------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 6 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2013, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Expander; use Expander;
with Exp_Ch6; use Exp_Ch6;
with Exp_Ch7; use Exp_Ch7;
with Exp_Ch9; use Exp_Ch9;
with Exp_Dbug; use Exp_Dbug;
with Exp_Disp; use Exp_Disp;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Fname; use Fname;
with Freeze; use Freeze;
with Itypes; use Itypes;
with Lib.Xref; use Lib.Xref;
with Layout; use Layout;
with Namet; use Namet;
with Lib; use Lib;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch4; use Sem_Ch4;
with Sem_Ch5; use Sem_Ch5;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch10; use Sem_Ch10;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Elim; use Sem_Elim;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Prag; use Sem_Prag;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Sem_Warn; use Sem_Warn;
with Sinput; use Sinput;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.CN; use Sinfo.CN;
with Snames; use Snames;
with Stringt; use Stringt;
with Style;
with Stylesw; use Stylesw;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
with Urealp; use Urealp;
with Validsw; use Validsw;
package body Sem_Ch6 is
May_Hide_Profile : Boolean := False;
-- This flag is used to indicate that two formals in two subprograms being
-- checked for conformance differ only in that one is an access parameter
-- while the other is of a general access type with the same designated
-- type. In this case, if the rest of the signatures match, a call to
-- either subprogram may be ambiguous, which is worth a warning. The flag
-- is set in Compatible_Types, and the warning emitted in
-- New_Overloaded_Entity.
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Null_Procedure
(N : Node_Id;
Is_Completion : out Boolean);
-- A null procedure can be a declaration or (Ada 2012) a completion.
procedure Analyze_Return_Statement (N : Node_Id);
-- Common processing for simple and extended return statements
procedure Analyze_Function_Return (N : Node_Id);
-- Subsidiary to Analyze_Return_Statement. Called when the return statement
-- applies to a [generic] function.
procedure Analyze_Return_Type (N : Node_Id);
-- Subsidiary to Process_Formals: analyze subtype mark in function
-- specification in a context where the formals are visible and hide
-- outer homographs.
procedure Analyze_Subprogram_Body_Helper (N : Node_Id);
-- Does all the real work of Analyze_Subprogram_Body. This is split out so
-- that we can use RETURN but not skip the debug output at the end.
procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
-- Analyze a generic subprogram body. N is the body to be analyzed, and
-- Gen_Id is the defining entity Id for the corresponding spec.
procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id);
-- If a subprogram has pragma Inline and inlining is active, use generic
-- machinery to build an unexpanded body for the subprogram. This body is
-- subsequently used for inline expansions at call sites. If subprogram can
-- be inlined (depending on size and nature of local declarations) this
-- function returns true. Otherwise subprogram body is treated normally.
-- If proper warnings are enabled and the subprogram contains a construct
-- that cannot be inlined, the offending construct is flagged accordingly.
function Can_Override_Operator (Subp : Entity_Id) return Boolean;
-- Returns true if Subp can override a predefined operator.
procedure Check_And_Build_Body_To_Inline
(N : Node_Id;
Spec_Id : Entity_Id;
Body_Id : Entity_Id);
-- Spec_Id and Body_Id are the entities of the specification and body of
-- the subprogram body N. If N can be inlined by the frontend (supported
-- cases documented in Check_Body_To_Inline) then build the body-to-inline
-- associated with N and attach it to the declaration node of Spec_Id.
procedure Check_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Ctype : Conformance_Type;
Errmsg : Boolean;
Conforms : out Boolean;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False;
Skip_Controlling_Formals : Boolean := False);
-- Given two entities, this procedure checks that the profiles associated
-- with these entities meet the conformance criterion given by the third
-- parameter. If they conform, Conforms is set True and control returns
-- to the caller. If they do not conform, Conforms is set to False, and
-- in addition, if Errmsg is True on the call, proper messages are output
-- to complain about the conformance failure. If Err_Loc is non_Empty
-- the error messages are placed on Err_Loc, if Err_Loc is empty, then
-- error messages are placed on the appropriate part of the construct
-- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
-- against a formal access-to-subprogram type so Get_Instance_Of must
-- be called.
procedure Check_Subprogram_Order (N : Node_Id);
-- N is the N_Subprogram_Body node for a subprogram. This routine applies
-- the alpha ordering rule for N if this ordering requirement applicable.
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean;
Proc : Entity_Id := Empty);
-- Called to check for missing return statements in a function body, or for
-- returns present in a procedure body which has No_Return set. HSS is the
-- handled statement sequence for the subprogram body. This procedure
-- checks all flow paths to make sure they either have return (Mode = 'F',
-- used for functions) or do not have a return (Mode = 'P', used for
-- No_Return procedures). The flag Err is set if there are any control
-- paths not explicitly terminated by a return in the function case, and is
-- True otherwise. Proc is the entity for the procedure case and is used
-- in posting the warning message.
procedure Check_Untagged_Equality (Eq_Op : Entity_Id);
-- In Ada 2012, a primitive equality operator on an untagged record type
-- must appear before the type is frozen, and have the same visibility as
-- that of the type. This procedure checks that this rule is met, and
-- otherwise emits an error on the subprogram declaration and a warning
-- on the earlier freeze point if it is easy to locate.
procedure Enter_Overloaded_Entity (S : Entity_Id);
-- This procedure makes S, a new overloaded entity, into the first visible
-- entity with that name.
function Is_Non_Overriding_Operation
(Prev_E : Entity_Id;
New_E : Entity_Id) return Boolean;
-- Enforce the rule given in 12.3(18): a private operation in an instance
-- overrides an inherited operation only if the corresponding operation
-- was overriding in the generic. This needs to be checked for primitive
-- operations of types derived (in the generic unit) from formal private
-- or formal derived types.
procedure Make_Inequality_Operator (S : Entity_Id);
-- Create the declaration for an inequality operator that is implicitly
-- created by a user-defined equality operator that yields a boolean.
procedure Process_PPCs
(N : Node_Id;
Spec_Id : Entity_Id;
Body_Id : Entity_Id);
-- Called from Analyze[_Generic]_Subprogram_Body to deal with scanning post
-- conditions for the body and assembling and inserting the _postconditions
-- procedure. N is the node for the subprogram body and Body_Id/Spec_Id are
-- the entities for the body and separate spec (if there is no separate
-- spec, Spec_Id is Empty). Note that invariants and predicates may also
-- provide postconditions, and are also handled in this procedure.
procedure Set_Formal_Validity (Formal_Id : Entity_Id);
-- Formal_Id is an formal parameter entity. This procedure deals with
-- setting the proper validity status for this entity, which depends on
-- the kind of parameter and the validity checking mode.
---------------------------------------------
-- Analyze_Abstract_Subprogram_Declaration --
---------------------------------------------
procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
Designator : constant Entity_Id :=
Analyze_Subprogram_Specification (Specification (N));
Scop : constant Entity_Id := Current_Scope;
begin
Check_SPARK_Restriction ("abstract subprogram is not allowed", N);
Generate_Definition (Designator);
Set_Contract (Designator, Make_Contract (Sloc (Designator)));
Set_Is_Abstract_Subprogram (Designator);
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
Set_Categorization_From_Scope (Designator, Scop);
if Ekind (Scope (Designator)) = E_Protected_Type then
Error_Msg_N
("abstract subprogram not allowed in protected type", N);
-- Issue a warning if the abstract subprogram is neither a dispatching
-- operation nor an operation that overrides an inherited subprogram or
-- predefined operator, since this most likely indicates a mistake.
elsif Warn_On_Redundant_Constructs
and then not Is_Dispatching_Operation (Designator)
and then not Present (Overridden_Operation (Designator))
and then (not Is_Operator_Symbol_Name (Chars (Designator))
or else Scop /= Scope (Etype (First_Formal (Designator))))
then
Error_Msg_N
("abstract subprogram is not dispatching or overriding?r?", N);
end if;
Generate_Reference_To_Formals (Designator);
Check_Eliminated (Designator);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Designator);
end if;
end Analyze_Abstract_Subprogram_Declaration;
---------------------------------
-- Analyze_Expression_Function --
---------------------------------
procedure Analyze_Expression_Function (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
LocX : constant Source_Ptr := Sloc (Expression (N));
Expr : constant Node_Id := Expression (N);
Spec : constant Node_Id := Specification (N);
Def_Id : Entity_Id;
Prev : Entity_Id;
-- If the expression is a completion, Prev is the entity whose
-- declaration is completed. Def_Id is needed to analyze the spec.
New_Body : Node_Id;
New_Decl : Node_Id;
New_Spec : Node_Id;
Ret : Node_Id;
begin
-- This is one of the occasions on which we transform the tree during
-- semantic analysis. If this is a completion, transform the expression
-- function into an equivalent subprogram body, and analyze it.
-- Expression functions are inlined unconditionally. The back-end will
-- determine whether this is possible.
Inline_Processing_Required := True;
-- Create a specification for the generated body. Types and defauts in
-- the profile are copies of the spec, but new entities must be created
-- for the unit name and the formals.
New_Spec := New_Copy_Tree (Spec);
Set_Defining_Unit_Name (New_Spec,
Make_Defining_Identifier (Sloc (Defining_Unit_Name (Spec)),
Chars (Defining_Unit_Name (Spec))));
if Present (Parameter_Specifications (New_Spec)) then
declare
Formal_Spec : Node_Id;
begin
Formal_Spec := First (Parameter_Specifications (New_Spec));
while Present (Formal_Spec) loop
Set_Defining_Identifier
(Formal_Spec,
Make_Defining_Identifier (Sloc (Formal_Spec),
Chars => Chars (Defining_Identifier (Formal_Spec))));
Next (Formal_Spec);
end loop;
end;
end if;
Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
-- If there are previous overloadable entities with the same name,
-- check whether any of them is completed by the expression function.
if Present (Prev) and then Is_Overloadable (Prev) then
Def_Id := Analyze_Subprogram_Specification (Spec);
Prev := Find_Corresponding_Spec (N);
end if;
Ret := Make_Simple_Return_Statement (LocX, Expression (N));
New_Body :=
Make_Subprogram_Body (Loc,
Specification => New_Spec,
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (LocX,
Statements => New_List (Ret)));
if Present (Prev) and then Ekind (Prev) = E_Generic_Function then
-- If the expression completes a generic subprogram, we must create a
-- separate node for the body, because at instantiation the original
-- node of the generic copy must be a generic subprogram body, and
-- cannot be a expression function. Otherwise we just rewrite the
-- expression with the non-generic body.
Insert_After (N, New_Body);
Rewrite (N, Make_Null_Statement (Loc));
Set_Has_Completion (Prev, False);
Analyze (N);
Analyze (New_Body);
Set_Is_Inlined (Prev);
elsif Present (Prev) and then Comes_From_Source (Prev) then
Set_Has_Completion (Prev, False);
-- For navigation purposes, indicate that the function is a body
Generate_Reference (Prev, Defining_Entity (N), 'b', Force => True);
Rewrite (N, New_Body);
Analyze (N);
-- Prev is the previous entity with the same name, but it is can
-- be an unrelated spec that is not completed by the expression
-- function. In that case the relevant entity is the one in the body.
-- Not clear that the backend can inline it in this case ???
if Has_Completion (Prev) then
Set_Is_Inlined (Prev);
-- The formals of the expression function are body formals,
-- and do not appear in the ali file, which will only contain
-- references to the formals of the original subprogram spec.
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (Def_Id);
F2 := First_Formal (Prev);
while Present (F1) loop
Set_Spec_Entity (F1, F2);
Next_Formal (F1);
Next_Formal (F2);
end loop;
end;
else
Set_Is_Inlined (Defining_Entity (New_Body));
end if;
-- If this is not a completion, create both a declaration and a body, so
-- that the expression can be inlined whenever possible.
else
-- An expression function that is not a completion is not a
-- subprogram declaration, and thus cannot appear in a protected
-- definition.
if Nkind (Parent (N)) = N_Protected_Definition then
Error_Msg_N
("an expression function is not a legal protected operation", N);
end if;
New_Decl :=
Make_Subprogram_Declaration (Loc, Specification => Spec);
Rewrite (N, New_Decl);
Analyze (N);
Set_Is_Inlined (Defining_Entity (New_Decl));
-- To prevent premature freeze action, insert the new body at the end
-- of the current declarations, or at the end of the package spec.
-- However, resolve usage names now, to prevent spurious visibility
-- on later entities.
declare
Decls : List_Id := List_Containing (N);
Par : constant Node_Id := Parent (Decls);
Id : constant Entity_Id := Defining_Entity (New_Decl);
begin
if Nkind (Par) = N_Package_Specification
and then Decls = Visible_Declarations (Par)
and then Present (Private_Declarations (Par))
and then not Is_Empty_List (Private_Declarations (Par))
then
Decls := Private_Declarations (Par);
end if;
Insert_After (Last (Decls), New_Body);
Push_Scope (Id);
Install_Formals (Id);
-- Do a preanalysis of the expression on a separate copy, to
-- prevent visibility issues later with operators in instances.
-- Attach copy to tree so that parent links are available.
declare
Expr : constant Node_Id := New_Copy_Tree (Expression (Ret));
begin
Set_Parent (Expr, Ret);
Preanalyze_Spec_Expression (Expr, Etype (Id));
end;
End_Scope;
end;
end if;
-- If the return expression is a static constant, we suppress warning
-- messages on unused formals, which in most cases will be noise.
Set_Is_Trivial_Subprogram (Defining_Entity (New_Body),
Is_OK_Static_Expression (Expr));
end Analyze_Expression_Function;
----------------------------------------
-- Analyze_Extended_Return_Statement --
----------------------------------------
procedure Analyze_Extended_Return_Statement (N : Node_Id) is
begin
Analyze_Return_Statement (N);
end Analyze_Extended_Return_Statement;
----------------------------
-- Analyze_Function_Call --
----------------------------
procedure Analyze_Function_Call (N : Node_Id) is
Actuals : constant List_Id := Parameter_Associations (N);
Func_Nam : constant Node_Id := Name (N);
Actual : Node_Id;
begin
Analyze (Func_Nam);
-- A call of the form A.B (X) may be an Ada 2005 call, which is
-- rewritten as B (A, X). If the rewriting is successful, the call
-- has been analyzed and we just return.
if Nkind (Func_Nam) = N_Selected_Component
and then Name (N) /= Func_Nam
and then Is_Rewrite_Substitution (N)
and then Present (Etype (N))
then
return;
end if;
-- If error analyzing name, then set Any_Type as result type and return
if Etype (Func_Nam) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- Otherwise analyze the parameters
if Present (Actuals) then
Actual := First (Actuals);
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
Next (Actual);
end loop;
end if;
Analyze_Call (N);
end Analyze_Function_Call;
-----------------------------
-- Analyze_Function_Return --
-----------------------------
procedure Analyze_Function_Return (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Stm_Entity : constant Entity_Id := Return_Statement_Entity (N);
Scope_Id : constant Entity_Id := Return_Applies_To (Stm_Entity);
R_Type : constant Entity_Id := Etype (Scope_Id);
-- Function result subtype
procedure Check_Limited_Return (Expr : Node_Id);
-- Check the appropriate (Ada 95 or Ada 2005) rules for returning
-- limited types. Used only for simple return statements.
-- Expr is the expression returned.
procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id);
-- Check that the return_subtype_indication properly matches the result
-- subtype of the function, as required by RM-6.5(5.1/2-5.3/2).
--------------------------
-- Check_Limited_Return --
--------------------------
procedure Check_Limited_Return (Expr : Node_Id) is
begin
-- Ada 2005 (AI-318-02): Return-by-reference types have been
-- removed and replaced by anonymous access results. This is an
-- incompatibility with Ada 95. Not clear whether this should be
-- enforced yet or perhaps controllable with special switch. ???
-- A limited interface that is not immutably limited is OK.
if Is_Limited_Interface (R_Type)
and then
not (Is_Task_Interface (R_Type)
or else Is_Protected_Interface (R_Type)
or else Is_Synchronized_Interface (R_Type))
then
null;
elsif Is_Limited_Type (R_Type)
and then not Is_Interface (R_Type)
and then Comes_From_Source (N)
and then not In_Instance_Body
and then not OK_For_Limited_Init_In_05 (R_Type, Expr)
then
-- Error in Ada 2005
if Ada_Version >= Ada_2005
and then not Debug_Flag_Dot_L
and then not GNAT_Mode
then
Error_Msg_N
("(Ada 2005) cannot copy object of a limited type " &
"(RM-2005 6.5(5.5/2))", Expr);
if Is_Immutably_Limited_Type (R_Type) then
Error_Msg_N
("\return by reference not permitted in Ada 2005", Expr);
end if;
-- Warn in Ada 95 mode, to give folks a heads up about this
-- incompatibility.
-- In GNAT mode, this is just a warning, to allow it to be
-- evilly turned off. Otherwise it is a real error.
-- In a generic context, simplify the warning because it makes
-- no sense to discuss pass-by-reference or copy.
elsif Warn_On_Ada_2005_Compatibility or GNAT_Mode then
if Inside_A_Generic then
Error_Msg_N
("return of limited object not permitted in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
elsif Is_Immutably_Limited_Type (R_Type) then
Error_Msg_N
("return by reference not permitted in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
else
Error_Msg_N
("cannot copy object of a limited type in Ada 2005 "
& "(RM-2005 6.5(5.5/2))?y?", Expr);
end if;
-- Ada 95 mode, compatibility warnings disabled
else
return; -- skip continuation messages below
end if;
if not Inside_A_Generic then
Error_Msg_N
("\consider switching to return of access type", Expr);
Explain_Limited_Type (R_Type, Expr);
end if;
end if;
end Check_Limited_Return;
-------------------------------------
-- Check_Return_Subtype_Indication --
-------------------------------------
procedure Check_Return_Subtype_Indication (Obj_Decl : Node_Id) is
Return_Obj : constant Node_Id := Defining_Identifier (Obj_Decl);
R_Stm_Type : constant Entity_Id := Etype (Return_Obj);
-- Subtype given in the extended return statement (must match R_Type)
Subtype_Ind : constant Node_Id :=
Object_Definition (Original_Node (Obj_Decl));
R_Type_Is_Anon_Access :
constant Boolean :=
Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type
or else
Ekind (R_Type) = E_Anonymous_Access_Protected_Subprogram_Type
or else
Ekind (R_Type) = E_Anonymous_Access_Type;
-- True if return type of the function is an anonymous access type
-- Can't we make Is_Anonymous_Access_Type in einfo ???
R_Stm_Type_Is_Anon_Access :
constant Boolean :=
Ekind (R_Stm_Type) = E_Anonymous_Access_Subprogram_Type
or else
Ekind (R_Stm_Type) = E_Anonymous_Access_Protected_Subprogram_Type
or else
Ekind (R_Stm_Type) = E_Anonymous_Access_Type;
-- True if type of the return object is an anonymous access type
begin
-- First, avoid cascaded errors
if Error_Posted (Obj_Decl) or else Error_Posted (Subtype_Ind) then
return;
end if;
-- "return access T" case; check that the return statement also has
-- "access T", and that the subtypes statically match:
-- if this is an access to subprogram the signatures must match.
if R_Type_Is_Anon_Access then
if R_Stm_Type_Is_Anon_Access then
if
Ekind (Designated_Type (R_Stm_Type)) /= E_Subprogram_Type
then
if Base_Type (Designated_Type (R_Stm_Type)) /=
Base_Type (Designated_Type (R_Type))
or else not Subtypes_Statically_Match (R_Stm_Type, R_Type)
then
Error_Msg_N
("subtype must statically match function result subtype",
Subtype_Mark (Subtype_Ind));
end if;
else
-- For two anonymous access to subprogram types, the
-- types themselves must be type conformant.
if not Conforming_Types
(R_Stm_Type, R_Type, Fully_Conformant)
then
Error_Msg_N
("subtype must statically match function result subtype",
Subtype_Ind);
end if;
end if;
else
Error_Msg_N ("must use anonymous access type", Subtype_Ind);
end if;
-- If the return object is of an anonymous access type, then report
-- an error if the function's result type is not also anonymous.
elsif R_Stm_Type_Is_Anon_Access
and then not R_Type_Is_Anon_Access
then
Error_Msg_N ("anonymous access not allowed for function with " &
"named access result", Subtype_Ind);
-- Subtype indication case: check that the return object's type is
-- covered by the result type, and that the subtypes statically match
-- when the result subtype is constrained. Also handle record types
-- with unknown discriminants for which we have built the underlying
-- record view. Coverage is needed to allow specific-type return
-- objects when the result type is class-wide (see AI05-32).
elsif Covers (Base_Type (R_Type), Base_Type (R_Stm_Type))
or else (Is_Underlying_Record_View (Base_Type (R_Stm_Type))
and then
Covers
(Base_Type (R_Type),
Underlying_Record_View (Base_Type (R_Stm_Type))))
then
-- A null exclusion may be present on the return type, on the
-- function specification, on the object declaration or on the
-- subtype itself.
if Is_Access_Type (R_Type)
and then
(Can_Never_Be_Null (R_Type)
or else Null_Exclusion_Present (Parent (Scope_Id))) /=
Can_Never_Be_Null (R_Stm_Type)
then
Error_Msg_N
("subtype must statically match function result subtype",
Subtype_Ind);
end if;
-- AI05-103: for elementary types, subtypes must statically match
if Is_Constrained (R_Type)
or else Is_Access_Type (R_Type)
then
if not Subtypes_Statically_Match (R_Stm_Type, R_Type) then
Error_Msg_N
("subtype must statically match function result subtype",
Subtype_Ind);
end if;
end if;
elsif Etype (Base_Type (R_Type)) = R_Stm_Type
and then Is_Null_Extension (Base_Type (R_Type))
then
null;
else
Error_Msg_N
("wrong type for return_subtype_indication", Subtype_Ind);
end if;
end Check_Return_Subtype_Indication;
---------------------
-- Local Variables --
---------------------
Expr : Node_Id;
-- Start of processing for Analyze_Function_Return
begin
Set_Return_Present (Scope_Id);
if Nkind (N) = N_Simple_Return_Statement then
Expr := Expression (N);
-- Guard against a malformed expression. The parser may have tried to
-- recover but the node is not analyzable.
if Nkind (Expr) = N_Error then
Set_Etype (Expr, Any_Type);
Expander_Mode_Save_And_Set (False);
return;
else
-- The resolution of a controlled [extension] aggregate associated
-- with a return statement creates a temporary which needs to be
-- finalized on function exit. Wrap the return statement inside a
-- block so that the finalization machinery can detect this case.
-- This early expansion is done only when the return statement is
-- not part of a handled sequence of statements.
if Nkind_In (Expr, N_Aggregate,
N_Extension_Aggregate)
and then Needs_Finalization (R_Type)
and then Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
then
Rewrite (N,
Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Relocate_Node (N)))));
Analyze (N);
return;
end if;
Analyze_And_Resolve (Expr, R_Type);
Check_Limited_Return (Expr);
end if;
-- RETURN only allowed in SPARK as the last statement in function
if Nkind (Parent (N)) /= N_Handled_Sequence_Of_Statements
and then
(Nkind (Parent (Parent (N))) /= N_Subprogram_Body
or else Present (Next (N)))
then
Check_SPARK_Restriction
("RETURN should be the last statement in function", N);
end if;
else
Check_SPARK_Restriction ("extended RETURN is not allowed", N);
-- Analyze parts specific to extended_return_statement:
declare
Obj_Decl : constant Node_Id :=
Last (Return_Object_Declarations (N));
Has_Aliased : constant Boolean := Aliased_Present (Obj_Decl);
HSS : constant Node_Id := Handled_Statement_Sequence (N);
begin
Expr := Expression (Obj_Decl);
-- Note: The check for OK_For_Limited_Init will happen in
-- Analyze_Object_Declaration; we treat it as a normal
-- object declaration.
Set_Is_Return_Object (Defining_Identifier (Obj_Decl));
Analyze (Obj_Decl);
Check_Return_Subtype_Indication (Obj_Decl);
if Present (HSS) then
Analyze (HSS);
if Present (Exception_Handlers (HSS)) then
-- ???Has_Nested_Block_With_Handler needs to be set.
-- Probably by creating an actual N_Block_Statement.
-- Probably in Expand.
null;
end if;
end if;
-- Mark the return object as referenced, since the return is an
-- implicit reference of the object.
Set_Referenced (Defining_Identifier (Obj_Decl));
Check_References (Stm_Entity);
-- Check RM 6.5 (5.9/3)
if Has_Aliased then
if Ada_Version < Ada_2012 then
-- Shouldn't this test Warn_On_Ada_2012_Compatibility ???
-- Can it really happen (extended return???)
Error_Msg_N
("aliased only allowed for limited"
& " return objects in Ada 2012?", N);
elsif not Is_Immutably_Limited_Type (R_Type) then
Error_Msg_N ("aliased only allowed for limited"
& " return objects", N);
end if;
end if;
end;
end if;
-- Case of Expr present
if Present (Expr)
-- Defend against previous errors
and then Nkind (Expr) /= N_Empty
and then Present (Etype (Expr))
then
-- Apply constraint check. Note that this is done before the implicit
-- conversion of the expression done for anonymous access types to
-- ensure correct generation of the null-excluding check associated
-- with null-excluding expressions found in return statements.
Apply_Constraint_Check (Expr, R_Type);
-- Ada 2005 (AI-318-02): When the result type is an anonymous access
-- type, apply an implicit conversion of the expression to that type
-- to force appropriate static and run-time accessibility checks.
if Ada_Version >= Ada_2005
and then Ekind (R_Type) = E_Anonymous_Access_Type
then
Rewrite (Expr, Convert_To (R_Type, Relocate_Node (Expr)));
Analyze_And_Resolve (Expr, R_Type);
-- If this is a local anonymous access to subprogram, the
-- accessibility check can be applied statically. The return is
-- illegal if the access type of the return expression is declared
-- inside of the subprogram (except if it is the subtype indication
-- of an extended return statement).
elsif Ekind (R_Type) = E_Anonymous_Access_Subprogram_Type then
if not Comes_From_Source (Current_Scope)
or else Ekind (Current_Scope) = E_Return_Statement
then
null;
elsif
Scope_Depth (Scope (Etype (Expr))) >= Scope_Depth (Scope_Id)
then
Error_Msg_N ("cannot return local access to subprogram", N);
end if;
end if;
-- If the result type is class-wide, then check that the return
-- expression's type is not declared at a deeper level than the
-- function (RM05-6.5(5.6/2)).
if Ada_Version >= Ada_2005
and then Is_Class_Wide_Type (R_Type)
then
if Type_Access_Level (Etype (Expr)) >
Subprogram_Access_Level (Scope_Id)
then
Error_Msg_N
("level of return expression type is deeper than " &
"class-wide function!", Expr);
end if;
end if;
-- Check incorrect use of dynamically tagged expression
if Is_Tagged_Type (R_Type) then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => R_Type,
Related_Nod => N);
end if;
-- ??? A real run-time accessibility check is needed in cases
-- involving dereferences of access parameters. For now we just
-- check the static cases.
if (Ada_Version < Ada_2005 or else Debug_Flag_Dot_L)
and then Is_Immutably_Limited_Type (Etype (Scope_Id))
and then Object_Access_Level (Expr) >
Subprogram_Access_Level (Scope_Id)
then
-- Suppress the message in a generic, where the rewriting
-- is irrelevant.
if Inside_A_Generic then
null;
else
Rewrite (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Accessibility_Check_Failed));
Analyze (N);
Error_Msg_N
("cannot return a local value by reference??", N);
Error_Msg_NE
("\& will be raised at run time??",
N, Standard_Program_Error);
end if;
end if;
if Known_Null (Expr)
and then Nkind (Parent (Scope_Id)) = N_Function_Specification
and then Null_Exclusion_Present (Parent (Scope_Id))
then
Apply_Compile_Time_Constraint_Error
(N => Expr,
Msg => "(Ada 2005) null not allowed for "
& "null-excluding return??",
Reason => CE_Null_Not_Allowed);
end if;
end if;
end Analyze_Function_Return;
-------------------------------------
-- Analyze_Generic_Subprogram_Body --
-------------------------------------
procedure Analyze_Generic_Subprogram_Body
(N : Node_Id;
Gen_Id : Entity_Id)
is
Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
Kind : constant Entity_Kind := Ekind (Gen_Id);
Body_Id : Entity_Id;
New_N : Node_Id;
Spec : Node_Id;
begin
-- Copy body and disable expansion while analyzing the generic For a
-- stub, do not copy the stub (which would load the proper body), this
-- will be done when the proper body is analyzed.
if Nkind (N) /= N_Subprogram_Body_Stub then
New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
Rewrite (N, New_N);
Start_Generic;
end if;
Spec := Specification (N);
-- Within the body of the generic, the subprogram is callable, and
-- behaves like the corresponding non-generic unit.
Body_Id := Defining_Entity (Spec);
if Kind = E_Generic_Procedure
and then Nkind (Spec) /= N_Procedure_Specification
then
Error_Msg_N ("invalid body for generic procedure ", Body_Id);
return;
elsif Kind = E_Generic_Function
and then Nkind (Spec) /= N_Function_Specification
then
Error_Msg_N ("invalid body for generic function ", Body_Id);
return;
end if;
Set_Corresponding_Body (Gen_Decl, Body_Id);
if Has_Completion (Gen_Id)
and then Nkind (Parent (N)) /= N_Subunit
then
Error_Msg_N ("duplicate generic body", N);
return;
else
Set_Has_Completion (Gen_Id);
end if;
if Nkind (N) = N_Subprogram_Body_Stub then
Set_Ekind (Defining_Entity (Specification (N)), Kind);
else
Set_Corresponding_Spec (N, Gen_Id);
end if;
if Nkind (Parent (N)) = N_Compilation_Unit then
Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
end if;
-- Make generic parameters immediately visible in the body. They are
-- needed to process the formals declarations. Then make the formals
-- visible in a separate step.
Push_Scope (Gen_Id);
declare
E : Entity_Id;
First_Ent : Entity_Id;
begin
First_Ent := First_Entity (Gen_Id);
E := First_Ent;
while Present (E) and then not Is_Formal (E) loop
Install_Entity (E);
Next_Entity (E);
end loop;
Set_Use (Generic_Formal_Declarations (Gen_Decl));
-- Now generic formals are visible, and the specification can be
-- analyzed, for subsequent conformance check.
Body_Id := Analyze_Subprogram_Specification (Spec);
-- Make formal parameters visible
if Present (E) then
-- E is the first formal parameter, we loop through the formals
-- installing them so that they will be visible.
Set_First_Entity (Gen_Id, E);
while Present (E) loop
Install_Entity (E);
Next_Formal (E);
end loop;
end if;
-- Visible generic entity is callable within its own body
Set_Ekind (Gen_Id, Ekind (Body_Id));
Set_Contract (Body_Id, Empty);
Set_Ekind (Body_Id, E_Subprogram_Body);
Set_Convention (Body_Id, Convention (Gen_Id));
Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Gen_Id));
Set_Scope (Body_Id, Scope (Gen_Id));
Check_Fully_Conformant (Body_Id, Gen_Id, Body_Id);
if Nkind (N) = N_Subprogram_Body_Stub then
-- No body to analyze, so restore state of generic unit
Set_Ekind (Gen_Id, Kind);
Set_Ekind (Body_Id, Kind);
if Present (First_Ent) then
Set_First_Entity (Gen_Id, First_Ent);
end if;
End_Scope;
return;
end if;
-- If this is a compilation unit, it must be made visible explicitly,
-- because the compilation of the declaration, unlike other library
-- unit declarations, does not. If it is not a unit, the following
-- is redundant but harmless.
Set_Is_Immediately_Visible (Gen_Id);
Reference_Body_Formals (Gen_Id, Body_Id);
if Is_Child_Unit (Gen_Id) then
Generate_Reference (Gen_Id, Scope (Gen_Id), 'k', False);
end if;
Set_Actual_Subtypes (N, Current_Scope);
-- Deal with preconditions and postconditions. In formal verification
-- mode, we keep pre- and postconditions attached to entities rather
-- than inserted in the code, in order to facilitate a distinct
-- treatment for them.
if not SPARK_Mode then
Process_PPCs (N, Gen_Id, Body_Id);
end if;
-- If the generic unit carries pre- or post-conditions, copy them
-- to the original generic tree, so that they are properly added
-- to any instantiation.
declare
Orig : constant Node_Id := Original_Node (N);
Cond : Node_Id;
begin
Cond := First (Declarations (N));
while Present (Cond) loop
if Nkind (Cond) = N_Pragma
and then Pragma_Name (Cond) = Name_Check
then
Prepend (New_Copy_Tree (Cond), Declarations (Orig));
elsif Nkind (Cond) = N_Pragma
and then Pragma_Name (Cond) = Name_Postcondition
then
Set_Ekind (Defining_Entity (Orig), Ekind (Gen_Id));
Prepend (New_Copy_Tree (Cond), Declarations (Orig));
else
exit;
end if;
Next (Cond);
end loop;
end;
Analyze_Declarations (Declarations (N));
Check_Completion;
Analyze (Handled_Statement_Sequence (N));
Save_Global_References (Original_Node (N));
-- Prior to exiting the scope, include generic formals again (if any
-- are present) in the set of local entities.
if Present (First_Ent) then
Set_First_Entity (Gen_Id, First_Ent);
end if;
Check_References (Gen_Id);
end;
Process_End_Label (Handled_Statement_Sequence (N), 't', Current_Scope);
End_Scope;
Check_Subprogram_Order (N);
-- Outside of its body, unit is generic again
Set_Ekind (Gen_Id, Kind);
Generate_Reference (Gen_Id, Body_Id, 'b', Set_Ref => False);
if Style_Check then
Style.Check_Identifier (Body_Id, Gen_Id);
end if;
End_Generic;
end Analyze_Generic_Subprogram_Body;
----------------------------
-- Analyze_Null_Procedure --
----------------------------
procedure Analyze_Null_Procedure
(N : Node_Id;
Is_Completion : out Boolean)
is
Loc : constant Source_Ptr := Sloc (N);
Spec : constant Node_Id := Specification (N);
Designator : Entity_Id;
Form : Node_Id;
Null_Body : Node_Id := Empty;
Prev : Entity_Id;
begin
-- Capture the profile of the null procedure before analysis, for
-- expansion at the freeze point and at each point of call. The body is
-- used if the procedure has preconditions, or if it is a completion. In
-- the first case the body is analyzed at the freeze point, in the other
-- it replaces the null procedure declaration.
Null_Body :=
Make_Subprogram_Body (Loc,
Specification => New_Copy_Tree (Spec),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Make_Null_Statement (Loc))));
-- Create new entities for body and formals
Set_Defining_Unit_Name (Specification (Null_Body),
Make_Defining_Identifier (Loc, Chars (Defining_Entity (N))));
Form := First (Parameter_Specifications (Specification (Null_Body)));
while Present (Form) loop
Set_Defining_Identifier (Form,
Make_Defining_Identifier (Loc, Chars (Defining_Identifier (Form))));
Next (Form);
end loop;
-- Determine whether the null procedure may be a completion of a generic
-- suprogram, in which case we use the new null body as the completion
-- and set minimal semantic information on the original declaration,
-- which is rewritten as a null statement.
Prev := Current_Entity_In_Scope (Defining_Entity (Spec));
if Present (Prev) and then Is_Generic_Subprogram (Prev) then
Insert_Before (N, Null_Body);
Set_Ekind (Defining_Entity (N), Ekind (Prev));
Set_Contract (Defining_Entity (N), Make_Contract (Loc));
Rewrite (N, Make_Null_Statement (Loc));
Analyze_Generic_Subprogram_Body (Null_Body, Prev);
Is_Completion := True;
return;
else
-- Resolve the types of the formals now, because the freeze point
-- may appear in a different context, e.g. an instantiation.
Form := First (Parameter_Specifications (Specification (Null_Body)));
while Present (Form) loop
if Nkind (Parameter_Type (Form)) /= N_Access_Definition then
Find_Type (Parameter_Type (Form));
elsif
No (Access_To_Subprogram_Definition (Parameter_Type (Form)))
then
Find_Type (Subtype_Mark (Parameter_Type (Form)));
else
-- The case of a null procedure with a formal that is an
-- access_to_subprogram type, and that is used as an actual
-- in an instantiation is left to the enthusiastic reader.
null;
end if;
Next (Form);
end loop;
end if;
-- If there are previous overloadable entities with the same name,
-- check whether any of them is completed by the null procedure.
if Present (Prev) and then Is_Overloadable (Prev) then
Designator := Analyze_Subprogram_Specification (Spec);
Prev := Find_Corresponding_Spec (N);
end if;
if No (Prev) or else not Comes_From_Source (Prev) then
Designator := Analyze_Subprogram_Specification (Spec);
Set_Has_Completion (Designator);
-- Signal to caller that this is a procedure declaration
Is_Completion := False;
-- Null procedures are always inlined, but generic formal subprograms
-- which appear as such in the internal instance of formal packages,
-- need no completion and are not marked Inline.
if Expander_Active
and then Nkind (N) /= N_Formal_Concrete_Subprogram_Declaration
then
Set_Corresponding_Body (N, Defining_Entity (Null_Body));
Set_Body_To_Inline (N, Null_Body);
Set_Is_Inlined (Designator);
end if;
else
-- The null procedure is a completion
Is_Completion := True;
if Expander_Active then
Rewrite (N, Null_Body);
Analyze (N);
else
Designator := Analyze_Subprogram_Specification (Spec);
Set_Has_Completion (Designator);
Set_Has_Completion (Prev);
end if;
end if;
end Analyze_Null_Procedure;
-----------------------------
-- Analyze_Operator_Symbol --
-----------------------------
-- An operator symbol such as "+" or "and" may appear in context where the
-- literal denotes an entity name, such as "+"(x, y) or in context when it
-- is just a string, as in (conjunction = "or"). In these cases the parser
-- generates this node, and the semantics does the disambiguation. Other
-- such case are actuals in an instantiation, the generic unit in an
-- instantiation, and pragma arguments.
procedure Analyze_Operator_Symbol (N : Node_Id) is
Par : constant Node_Id := Parent (N);
begin
if (Nkind (Par) = N_Function_Call
and then N = Name (Par))
or else Nkind (Par) = N_Function_Instantiation
or else (Nkind (Par) = N_Indexed_Component
and then N = Prefix (Par))
or else (Nkind (Par) = N_Pragma_Argument_Association
and then not Is_Pragma_String_Literal (Par))
or else Nkind (Par) = N_Subprogram_Renaming_Declaration
or else (Nkind (Par) = N_Attribute_Reference
and then Attribute_Name (Par) /= Name_Value)
then
Find_Direct_Name (N);
else
Change_Operator_Symbol_To_String_Literal (N);
Analyze (N);
end if;
end Analyze_Operator_Symbol;
-----------------------------------
-- Analyze_Parameter_Association --
-----------------------------------
procedure Analyze_Parameter_Association (N : Node_Id) is
begin
Analyze (Explicit_Actual_Parameter (N));
end Analyze_Parameter_Association;
----------------------------
-- Analyze_Procedure_Call --
----------------------------
procedure Analyze_Procedure_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Name (N);
Actuals : constant List_Id := Parameter_Associations (N);
Actual : Node_Id;
New_N : Node_Id;
procedure Analyze_Call_And_Resolve;
-- Do Analyze and Resolve calls for procedure call
-- At end, check illegal order dependence.
------------------------------
-- Analyze_Call_And_Resolve --
------------------------------
procedure Analyze_Call_And_Resolve is
begin
if Nkind (N) = N_Procedure_Call_Statement then
Analyze_Call (N);
Resolve (N, Standard_Void_Type);
else
Analyze (N);
end if;
end Analyze_Call_And_Resolve;
-- Start of processing for Analyze_Procedure_Call
begin
-- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
-- a procedure call or an entry call. The prefix may denote an access
-- to subprogram type, in which case an implicit dereference applies.
-- If the prefix is an indexed component (without implicit dereference)
-- then the construct denotes a call to a member of an entire family.
-- If the prefix is a simple name, it may still denote a call to a
-- parameterless member of an entry family. Resolution of these various
-- interpretations is delicate.
Analyze (P);
-- If this is a call of the form Obj.Op, the call may have been
-- analyzed and possibly rewritten into a block, in which case
-- we are done.
if Analyzed (N) then
return;
end if;
-- If there is an error analyzing the name (which may have been
-- rewritten if the original call was in prefix notation) then error
-- has been emitted already, mark node and return.
if Error_Posted (N) or else Etype (Name (N)) = Any_Type then
Set_Etype (N, Any_Type);
return;
end if;
-- Otherwise analyze the parameters
if Present (Actuals) then
Actual := First (Actuals);
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
Next (Actual);
end loop;
end if;
-- Special processing for Elab_Spec, Elab_Body and Elab_Subp_Body calls
if Nkind (P) = N_Attribute_Reference
and then Nam_In (Attribute_Name (P), Name_Elab_Spec,
Name_Elab_Body,
Name_Elab_Subp_Body)
then
if Present (Actuals) then
Error_Msg_N
("no parameters allowed for this call", First (Actuals));
return;
end if;
Set_Etype (N, Standard_Void_Type);
Set_Analyzed (N);
elsif Is_Entity_Name (P)
and then Is_Record_Type (Etype (Entity (P)))
and then Remote_AST_I_Dereference (P)
then
return;
elsif Is_Entity_Name (P)
and then Ekind (Entity (P)) /= E_Entry_Family
then
if Is_Access_Type (Etype (P))
and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
and then No (Actuals)
and then Comes_From_Source (N)
then
Error_Msg_N ("missing explicit dereference in call", N);
end if;
Analyze_Call_And_Resolve;
-- If the prefix is the simple name of an entry family, this is
-- a parameterless call from within the task body itself.
elsif Is_Entity_Name (P)
and then Nkind (P) = N_Identifier
and then Ekind (Entity (P)) = E_Entry_Family
and then Present (Actuals)
and then No (Next (First (Actuals)))
then
-- Can be call to parameterless entry family. What appears to be the
-- sole argument is in fact the entry index. Rewrite prefix of node
-- accordingly. Source representation is unchanged by this
-- transformation.
New_N :=
Make_Indexed_Component (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
Expressions => Actuals);
Set_Name (N, New_N);
Set_Etype (New_N, Standard_Void_Type);
Set_Parameter_Associations (N, No_List);
Analyze_Call_And_Resolve;
elsif Nkind (P) = N_Explicit_Dereference then
if Ekind (Etype (P)) = E_Subprogram_Type then
Analyze_Call_And_Resolve;
else
Error_Msg_N ("expect access to procedure in call", P);
end if;
-- The name can be a selected component or an indexed component that
-- yields an access to subprogram. Such a prefix is legal if the call
-- has parameter associations.
elsif Is_Access_Type (Etype (P))
and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
then
if Present (Actuals) then
Analyze_Call_And_Resolve;
else
Error_Msg_N ("missing explicit dereference in call ", N);
end if;
-- If not an access to subprogram, then the prefix must resolve to the
-- name of an entry, entry family, or protected operation.
-- For the case of a simple entry call, P is a selected component where
-- the prefix is the task and the selector name is the entry. A call to
-- a protected procedure will have the same syntax. If the protected
-- object contains overloaded operations, the entity may appear as a
-- function, the context will select the operation whose type is Void.
elsif Nkind (P) = N_Selected_Component
and then Ekind_In (Entity (Selector_Name (P)), E_Entry,
E_Procedure,
E_Function)
then
Analyze_Call_And_Resolve;
elsif Nkind (P) = N_Selected_Component
and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
and then Present (Actuals)
and then No (Next (First (Actuals)))
then
-- Can be call to parameterless entry family. What appears to be the
-- sole argument is in fact the entry index. Rewrite prefix of node
-- accordingly. Source representation is unchanged by this
-- transformation.
New_N :=
Make_Indexed_Component (Loc,
Prefix => New_Copy (P),
Expressions => Actuals);
Set_Name (N, New_N);
Set_Etype (New_N, Standard_Void_Type);
Set_Parameter_Associations (N, No_List);
Analyze_Call_And_Resolve;
-- For the case of a reference to an element of an entry family, P is
-- an indexed component whose prefix is a selected component (task and
-- entry family), and whose index is the entry family index.
elsif Nkind (P) = N_Indexed_Component
and then Nkind (Prefix (P)) = N_Selected_Component
and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
then
Analyze_Call_And_Resolve;
-- If the prefix is the name of an entry family, it is a call from
-- within the task body itself.
elsif Nkind (P) = N_Indexed_Component
and then Nkind (Prefix (P)) = N_Identifier
and then Ekind (Entity (Prefix (P))) = E_Entry_Family
then
New_N :=
Make_Selected_Component (Loc,
Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
Rewrite (Prefix (P), New_N);
Analyze (P);
Analyze_Call_And_Resolve;
-- In Ada 2012. a qualified expression is a name, but it cannot be a
-- procedure name, so the construct can only be a qualified expression.
elsif Nkind (P) = N_Qualified_Expression
and then Ada_Version >= Ada_2012
then
Rewrite (N, Make_Code_Statement (Loc, Expression => P));
Analyze (N);
-- Anything else is an error
else
Error_Msg_N ("invalid procedure or entry call", N);
end if;
end Analyze_Procedure_Call;
------------------------------
-- Analyze_Return_Statement --
------------------------------
procedure Analyze_Return_Statement (N : Node_Id) is
pragma Assert (Nkind_In (N, N_Simple_Return_Statement,
N_Extended_Return_Statement));
Returns_Object : constant Boolean :=
Nkind (N) = N_Extended_Return_Statement
or else
(Nkind (N) = N_Simple_Return_Statement
and then Present (Expression (N)));
-- True if we're returning something; that is, "return <expression>;"
-- or "return Result : T [:= ...]". False for "return;". Used for error
-- checking: If Returns_Object is True, N should apply to a function
-- body; otherwise N should apply to a procedure body, entry body,
-- accept statement, or extended return statement.
function Find_What_It_Applies_To return Entity_Id;
-- Find the entity representing the innermost enclosing body, accept
-- statement, or extended return statement. If the result is a callable
-- construct or extended return statement, then this will be the value
-- of the Return_Applies_To attribute. Otherwise, the program is
-- illegal. See RM-6.5(4/2).
-----------------------------
-- Find_What_It_Applies_To --
-----------------------------
function Find_What_It_Applies_To return Entity_Id is
Result : Entity_Id := Empty;
begin
-- Loop outward through the Scope_Stack, skipping blocks, loops,
-- and postconditions.
for J in reverse 0 .. Scope_Stack.Last loop
Result := Scope_Stack.Table (J).Entity;
exit when not Ekind_In (Result, E_Block, E_Loop)
and then Chars (Result) /= Name_uPostconditions;
end loop;
pragma Assert (Present (Result));
return Result;
end Find_What_It_Applies_To;
-- Local declarations
Scope_Id : constant Entity_Id := Find_What_It_Applies_To;
Kind : constant Entity_Kind := Ekind (Scope_Id);
Loc : constant Source_Ptr := Sloc (N);
Stm_Entity : constant Entity_Id :=
New_Internal_Entity
(E_Return_Statement, Current_Scope, Loc, 'R');
-- Start of processing for Analyze_Return_Statement
begin
Set_Return_Statement_Entity (N, Stm_Entity);
Set_Etype (Stm_Entity, Standard_Void_Type);
Set_Return_Applies_To (Stm_Entity, Scope_Id);
-- Place Return entity on scope stack, to simplify enforcement of 6.5
-- (4/2): an inner return statement will apply to this extended return.
if Nkind (N) = N_Extended_Return_Statement then
Push_Scope (Stm_Entity);
end if;
-- Check that pragma No_Return is obeyed. Don't complain about the
-- implicitly-generated return that is placed at the end.
if No_Return (Scope_Id) and then Comes_From_Source (N) then
Error_Msg_N ("RETURN statement not allowed (No_Return)", N);
end if;
-- Warn on any unassigned OUT parameters if in procedure
if Ekind (Scope_Id) = E_Procedure then
Warn_On_Unassigned_Out_Parameter (N, Scope_Id);
end if;
-- Check that functions return objects, and other things do not
if Kind = E_Function or else Kind = E_Generic_Function then
if not Returns_Object then
Error_Msg_N ("missing expression in return from function", N);
end if;
elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
if Returns_Object then
Error_Msg_N ("procedure cannot return value (use function)", N);
end if;
elsif Kind = E_Entry or else Kind = E_Entry_Family then
if Returns_Object then
if Is_Protected_Type (Scope (Scope_Id)) then
Error_Msg_N ("entry body cannot return value", N);
else
Error_Msg_N ("accept statement cannot return value", N);
end if;
end if;
elsif Kind = E_Return_Statement then
-- We are nested within another return statement, which must be an
-- extended_return_statement.
if Returns_Object then
if Nkind (N) = N_Extended_Return_Statement then
Error_Msg_N
("extended return statement cannot be nested (use `RETURN;`)",
N);
-- Case of a simple return statement with a value inside extended
-- return statement.
else
Error_Msg_N
("return nested in extended return statement cannot return " &
"value (use `RETURN;`)", N);
end if;
end if;
else
Error_Msg_N ("illegal context for return statement", N);
end if;
if Ekind_In (Kind, E_Function, E_Generic_Function) then
Analyze_Function_Return (N);
elsif Ekind_In (Kind, E_Procedure, E_Generic_Procedure) then
Set_Return_Present (Scope_Id);
end if;
if Nkind (N) = N_Extended_Return_Statement then
End_Scope;
end if;
Kill_Current_Values (Last_Assignment_Only => True);
Check_Unreachable_Code (N);
Analyze_Dimension (N);
end Analyze_Return_Statement;
-------------------------------------
-- Analyze_Simple_Return_Statement --
-------------------------------------
procedure Analyze_Simple_Return_Statement (N : Node_Id) is
begin
if Present (Expression (N)) then
Mark_Coextensions (N, Expression (N));
end if;
Analyze_Return_Statement (N);
end Analyze_Simple_Return_Statement;
-------------------------
-- Analyze_Return_Type --
-------------------------
procedure Analyze_Return_Type (N : Node_Id) is
Designator : constant Entity_Id := Defining_Entity (N);
Typ : Entity_Id := Empty;
begin
-- Normal case where result definition does not indicate an error
if Result_Definition (N) /= Error then
if Nkind (Result_Definition (N)) = N_Access_Definition then
Check_SPARK_Restriction
("access result is not allowed", Result_Definition (N));
-- Ada 2005 (AI-254): Handle anonymous access to subprograms
declare
AD : constant Node_Id :=
Access_To_Subprogram_Definition (Result_Definition (N));
begin
if Present (AD) and then Protected_Present (AD) then
Typ := Replace_Anonymous_Access_To_Protected_Subprogram (N);
else
Typ := Access_Definition (N, Result_Definition (N));
end if;
end;
Set_Parent (Typ, Result_Definition (N));
Set_Is_Local_Anonymous_Access (Typ);
Set_Etype (Designator, Typ);
-- Ada 2005 (AI-231): Ensure proper usage of null exclusion
Null_Exclusion_Static_Checks (N);
-- Subtype_Mark case
else
Find_Type (Result_Definition (N));
Typ := Entity (Result_Definition (N));
Set_Etype (Designator, Typ);
-- Unconstrained array as result is not allowed in SPARK
if Is_Array_Type (Typ) and then not Is_Constrained (Typ) then
Check_SPARK_Restriction
("returning an unconstrained array is not allowed",
Result_Definition (N));
end if;
-- Ada 2005 (AI-231): Ensure proper usage of null exclusion
Null_Exclusion_Static_Checks (N);
-- If a null exclusion is imposed on the result type, then create
-- a null-excluding itype (an access subtype) and use it as the
-- function's Etype. Note that the null exclusion checks are done
-- right before this, because they don't get applied to types that
-- do not come from source.
if Is_Access_Type (Typ) and then Null_Exclusion_Present (N) then
Set_Etype (Designator,
Create_Null_Excluding_Itype
(T => Typ,
Related_Nod => N,
Scope_Id => Scope (Current_Scope)));
-- The new subtype must be elaborated before use because
-- it is visible outside of the function. However its base
-- type may not be frozen yet, so the reference that will
-- force elaboration must be attached to the freezing of
-- the base type.
-- If the return specification appears on a proper body,
-- the subtype will have been created already on the spec.
if Is_Frozen (Typ) then
if Nkind (Parent (N)) = N_Subprogram_Body
and then Nkind (Parent (Parent (N))) = N_Subunit
then
null;
else
Build_Itype_Reference (Etype (Designator), Parent (N));
end if;
else
Ensure_Freeze_Node (Typ);
declare
IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
begin
Set_Itype (IR, Etype (Designator));
Append_Freeze_Actions (Typ, New_List (IR));
end;
end if;
else
Set_Etype (Designator, Typ);
end if;
if Ekind (Typ) = E_Incomplete_Type
and then Is_Value_Type (Typ)
then
null;
elsif Ekind (Typ) = E_Incomplete_Type
or else (Is_Class_Wide_Type (Typ)
and then Ekind (Root_Type (Typ)) = E_Incomplete_Type)
then
-- AI05-0151: Tagged incomplete types are allowed in all formal
-- parts. Untagged incomplete types are not allowed in bodies.
if Ada_Version >= Ada_2012 then
if Is_Tagged_Type (Typ) then
null;
elsif Nkind_In (Parent (Parent (N)),
N_Accept_Statement,
N_Entry_Body,
N_Subprogram_Body)
then
Error_Msg_NE
("invalid use of untagged incomplete type&",
Designator, Typ);
end if;
-- The type must be completed in the current package. This
-- is checked at the end of the package declaraton, when
-- Taft-amendment types are identified. If the return type
-- is class-wide, there is no required check, the type can
-- be a bona fide TAT.
if Ekind (Scope (Current_Scope)) = E_Package
and then In_Private_Part (Scope (Current_Scope))
and then not Is_Class_Wide_Type (Typ)
then
Append_Elmt (Designator, Private_Dependents (Typ));
end if;
else
Error_Msg_NE
("invalid use of incomplete type&", Designator, Typ);
end if;
end if;
end if;
-- Case where result definition does indicate an error
else
Set_Etype (Designator, Any_Type);
end if;
end Analyze_Return_Type;
-----------------------------
-- Analyze_Subprogram_Body --
-----------------------------
procedure Analyze_Subprogram_Body (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Body_Spec : constant Node_Id := Specification (N);
Body_Id : constant Entity_Id := Defining_Entity (Body_Spec);
begin
if Debug_Flag_C then
Write_Str ("==> subprogram body ");
Write_Name (Chars (Body_Id));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
Indent;
end if;
Trace_Scope (N, Body_Id, " Analyze subprogram: ");
-- The real work is split out into the helper, so it can do "return;"
-- without skipping the debug output:
Analyze_Subprogram_Body_Helper (N);
if Debug_Flag_C then
Outdent;
Write_Str ("<== subprogram body ");
Write_Name (Chars (Body_Id));
Write_Str (" from ");
Write_Location (Loc);
Write_Eol;
end if;
end Analyze_Subprogram_Body;
------------------------------------
-- Analyze_Subprogram_Body_Helper --
------------------------------------
-- This procedure is called for regular subprogram bodies, generic bodies,
-- and for subprogram stubs of both kinds. In the case of stubs, only the
-- specification matters, and is used to create a proper declaration for
-- the subprogram, or to perform conformance checks.
procedure Analyze_Subprogram_Body_Helper (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Body_Spec : constant Node_Id := Specification (N);
Body_Id : Entity_Id := Defining_Entity (Body_Spec);
Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
Conformant : Boolean;
HSS : Node_Id;
Prot_Typ : Entity_Id := Empty;
Spec_Id : Entity_Id;
Spec_Decl : Node_Id := Empty;
Last_Real_Spec_Entity : Entity_Id := Empty;
-- When we analyze a separate spec, the entity chain ends up containing
-- the formals, as well as any itypes generated during analysis of the
-- default expressions for parameters, or the arguments of associated
-- precondition/postcondition pragmas (which are analyzed in the context
-- of the spec since they have visibility on formals).
--
-- These entities belong with the spec and not the body. However we do
-- the analysis of the body in the context of the spec (again to obtain
-- visibility to the formals), and all the entities generated during
-- this analysis end up also chained to the entity chain of the spec.
-- But they really belong to the body, and there is circuitry to move
-- them from the spec to the body.
--
-- However, when we do this move, we don't want to move the real spec
-- entities (first para above) to the body. The Last_Real_Spec_Entity
-- variable points to the last real spec entity, so we only move those
-- chained beyond that point. It is initialized to Empty to deal with
-- the case where there is no separate spec.
procedure Check_Anonymous_Return;
-- Ada 2005: if a function returns an access type that denotes a task,
-- or a type that contains tasks, we must create a master entity for
-- the anonymous type, which typically will be used in an allocator
-- in the body of the function.
procedure Check_Inline_Pragma (Spec : in out Node_Id);
-- Look ahead to recognize a pragma that may appear after the body.
-- If there is a previous spec, check that it appears in the same
-- declarative part. If the pragma is Inline_Always, perform inlining
-- unconditionally, otherwise only if Front_End_Inlining is requested.
-- If the body acts as a spec, and inlining is required, we create a
-- subprogram declaration for it, in order to attach the body to inline.
-- If pragma does not appear after the body, check whether there is
-- an inline pragma before any local declarations.
procedure Check_Missing_Return;
-- Checks for a function with a no return statements, and also performs
-- the warning checks implemented by Check_Returns. In formal mode, also
-- verify that a function ends with a RETURN and that a procedure does
-- not contain any RETURN.
function Disambiguate_Spec return Entity_Id;
-- When a primitive is declared between the private view and the full
-- view of a concurrent type which implements an interface, a special
-- mechanism is used to find the corresponding spec of the primitive
-- body.
procedure Exchange_Limited_Views (Subp_Id : Entity_Id);
-- Ada 2012 (AI05-0151): Detect whether the profile of Subp_Id contains
-- incomplete types coming from a limited context and swap their limited
-- views with the non-limited ones.
function Is_Private_Concurrent_Primitive
(Subp_Id : Entity_Id) return Boolean;
-- Determine whether subprogram Subp_Id is a primitive of a concurrent
-- type that implements an interface and has a private view.
procedure Set_Trivial_Subprogram (N : Node_Id);
-- Sets the Is_Trivial_Subprogram flag in both spec and body of the
-- subprogram whose body is being analyzed. N is the statement node
-- causing the flag to be set, if the following statement is a return
-- of an entity, we mark the entity as set in source to suppress any
-- warning on the stylized use of function stubs with a dummy return.
procedure Verify_Overriding_Indicator;
-- If there was a previous spec, the entity has been entered in the
-- current scope previously. If the body itself carries an overriding
-- indicator, check that it is consistent with the known status of the
-- entity.
----------------------------
-- Check_Anonymous_Return --
----------------------------
procedure Check_Anonymous_Return is
Decl : Node_Id;
Par : Node_Id;
Scop : Entity_Id;
begin
if Present (Spec_Id) then
Scop := Spec_Id;
else
Scop := Body_Id;
end if;
if Ekind (Scop) = E_Function
and then Ekind (Etype (Scop)) = E_Anonymous_Access_Type
and then not Is_Thunk (Scop)
and then (Has_Task (Designated_Type (Etype (Scop)))
or else
(Is_Class_Wide_Type (Designated_Type (Etype (Scop)))
and then
Is_Limited_Record (Designated_Type (Etype (Scop)))))
and then Expander_Active
-- Avoid cases with no tasking support
and then RTE_Available (RE_Current_Master)
and then not Restriction_Active (No_Task_Hierarchy)
then
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uMaster),
Constant_Present => True,
Object_Definition =>
New_Reference_To (RTE (RE_Master_Id), Loc),
Expression =>
Make_Explicit_Dereference (Loc,
New_Reference_To (RTE (RE_Current_Master), Loc)));
if Present (Declarations (N)) then
Prepend (Decl, Declarations (N));
else
Set_Declarations (N, New_List (Decl));
end if;
Set_Master_Id (Etype (Scop), Defining_Identifier (Decl));
Set_Has_Master_Entity (Scop);
-- Now mark the containing scope as a task master
Par := N;
while Nkind (Par) /= N_Compilation_Unit loop
Par := Parent (Par);
pragma Assert (Present (Par));
-- If we fall off the top, we are at the outer level, and
-- the environment task is our effective master, so nothing
-- to mark.
if Nkind_In
(Par, N_Task_Body, N_Block_Statement, N_Subprogram_Body)
then
Set_Is_Task_Master (Par, True);
exit;
end if;
end loop;
end if;
end Check_Anonymous_Return;
-------------------------
-- Check_Inline_Pragma --
-------------------------
procedure Check_Inline_Pragma (Spec : in out Node_Id) is
Prag : Node_Id;
Plist : List_Id;
function Is_Inline_Pragma (N : Node_Id) return Boolean;
-- True when N is a pragma Inline or Inline_Always that applies
-- to this subprogram.
-----------------------
-- Is_Inline_Pragma --
-----------------------
function Is_Inline_Pragma (N : Node_Id) return Boolean is
begin
return
Nkind (N) = N_Pragma
and then
(Pragma_Name (N) = Name_Inline_Always
or else
(Front_End_Inlining
and then Pragma_Name (N) = Name_Inline))
and then
Chars
(Expression (First (Pragma_Argument_Associations (N)))) =
Chars (Body_Id);
end Is_Inline_Pragma;
-- Start of processing for Check_Inline_Pragma
begin
if not Expander_Active then
return;
end if;
if Is_List_Member (N)
and then Present (Next (N))
and then Is_Inline_Pragma (Next (N))
then
Prag := Next (N);
elsif Nkind (N) /= N_Subprogram_Body_Stub
and then Present (Declarations (N))
and then Is_Inline_Pragma (First (Declarations (N)))
then
Prag := First (Declarations (N));
else
Prag := Empty;
end if;
if Present (Prag) then
if Present (Spec_Id) then
if In_Same_List (N, Unit_Declaration_Node (Spec_Id)) then
Analyze (Prag);
end if;
else
-- Create a subprogram declaration, to make treatment uniform
declare
Subp : constant Entity_Id :=
Make_Defining_Identifier (Loc, Chars (Body_Id));
Decl : constant Node_Id :=
Make_Subprogram_Declaration (Loc,
Specification =>
New_Copy_Tree (Specification (N)));
begin
Set_Defining_Unit_Name (Specification (Decl), Subp);
if Present (First_Formal (Body_Id)) then
Plist := Copy_Parameter_List (Body_Id);
Set_Parameter_Specifications
(Specification (Decl), Plist);
end if;
Insert_Before (N, Decl);
Analyze (Decl);
Analyze (Prag);
Set_Has_Pragma_Inline (Subp);
if Pragma_Name (Prag) = Name_Inline_Always then
Set_Is_Inlined (Subp);
Set_Has_Pragma_Inline_Always (Subp);
end if;
Spec := Subp;
end;
end if;
end if;
end Check_Inline_Pragma;
--------------------------
-- Check_Missing_Return --
--------------------------
procedure Check_Missing_Return is
Id : Entity_Id;
Missing_Ret : Boolean;
begin
if Nkind (Body_Spec) = N_Function_Specification then
if Present (Spec_Id) then
Id := Spec_Id;
else
Id := Body_Id;
end if;
if Return_Present (Id) then
Check_Returns (HSS, 'F', Missing_Ret);
if Missing_Ret then
Set_Has_Missing_Return (Id);
end if;
elsif Is_Generic_Subprogram (Id)
or else not Is_Machine_Code_Subprogram (Id)
then
Error_Msg_N ("missing RETURN statement in function body", N);
end if;
-- If procedure with No_Return, check returns
elsif Nkind (Body_Spec) = N_Procedure_Specification
and then Present (Spec_Id)
and then No_Return (Spec_Id)
then
Check_Returns (HSS, 'P', Missing_Ret, Spec_Id);
end if;
-- Special checks in SPARK mode
if Nkind (Body_Spec) = N_Function_Specification then
-- In SPARK mode, last statement of a function should be a return
declare
Stat : constant Node_Id := Last_Source_Statement (HSS);
begin
if Present (Stat)
and then not Nkind_In (Stat, N_Simple_Return_Statement,
N_Extended_Return_Statement)
then
Check_SPARK_Restriction
("last statement in function should be RETURN", Stat);
end if;
end;
-- In SPARK mode, verify that a procedure has no return
elsif Nkind (Body_Spec) = N_Procedure_Specification then
if Present (Spec_Id) then
Id := Spec_Id;
else
Id := Body_Id;
end if;
-- Would be nice to point to return statement here, can we
-- borrow the Check_Returns procedure here ???
if Return_Present (Id) then
Check_SPARK_Restriction
("procedure should not have RETURN", N);
end if;
end if;
end Check_Missing_Return;
-----------------------
-- Disambiguate_Spec --
-----------------------
function Disambiguate_Spec return Entity_Id is
Priv_Spec : Entity_Id;
Spec_N : Entity_Id;
procedure Replace_Types (To_Corresponding : Boolean);
-- Depending on the flag, replace the type of formal parameters of
-- Body_Id if it is a concurrent type implementing interfaces with
-- the corresponding record type or the other way around.
procedure Replace_Types (To_Corresponding : Boolean) is
Formal : Entity_Id;
Formal_Typ : Entity_Id;
begin
Formal := First_Formal (Body_Id);
while Present (Formal) loop
Formal_Typ := Etype (Formal);
if Is_Class_Wide_Type (Formal_Typ) then
Formal_Typ := Root_Type (Formal_Typ);
end if;
-- From concurrent type to corresponding record
if To_Corresponding then
if Is_Concurrent_Type (Formal_Typ)
and then Present (Corresponding_Record_Type (Formal_Typ))
and then Present (Interfaces (
Corresponding_Record_Type (Formal_Typ)))
then
Set_Etype (Formal,
Corresponding_Record_Type (Formal_Typ));
end if;
-- From corresponding record to concurrent type
else
if Is_Concurrent_Record_Type (Formal_Typ)
and then Present (Interfaces (Formal_Typ))
then
Set_Etype (Formal,
Corresponding_Concurrent_Type (Formal_Typ));
end if;
end if;
Next_Formal (Formal);
end loop;
end Replace_Types;
-- Start of processing for Disambiguate_Spec
begin
-- Try to retrieve the specification of the body as is. All error
-- messages are suppressed because the body may not have a spec in
-- its current state.
Spec_N := Find_Corresponding_Spec (N, False);
-- It is possible that this is the body of a primitive declared
-- between a private and a full view of a concurrent type. The
-- controlling parameter of the spec carries the concurrent type,
-- not the corresponding record type as transformed by Analyze_
-- Subprogram_Specification. In such cases, we undo the change
-- made by the analysis of the specification and try to find the
-- spec again.
-- Note that wrappers already have their corresponding specs and
-- bodies set during their creation, so if the candidate spec is
-- a wrapper, then we definitely need to swap all types to their
-- original concurrent status.
if No (Spec_N)
or else Is_Primitive_Wrapper (Spec_N)
then
-- Restore all references of corresponding record types to the
-- original concurrent types.
Replace_Types (To_Corresponding => False);
Priv_Spec := Find_Corresponding_Spec (N, False);
-- The current body truly belongs to a primitive declared between
-- a private and a full view. We leave the modified body as is,
-- and return the true spec.
if Present (Priv_Spec)
and then Is_Private_Primitive (Priv_Spec)
then
return Priv_Spec;
end if;
-- In case that this is some sort of error, restore the original
-- state of the body.
Replace_Types (To_Corresponding => True);
end if;
return Spec_N;
end Disambiguate_Spec;
----------------------------
-- Exchange_Limited_Views --
----------------------------
procedure Exchange_Limited_Views (Subp_Id : Entity_Id) is
procedure Detect_And_Exchange (Id : Entity_Id);
-- Determine whether Id's type denotes an incomplete type associated
-- with a limited with clause and exchange the limited view with the
-- non-limited one.
-------------------------
-- Detect_And_Exchange --
-------------------------
procedure Detect_And_Exchange (Id : Entity_Id) is
Typ : constant Entity_Id := Etype (Id);
begin
if Ekind (Typ) = E_Incomplete_Type
and then From_With_Type (Typ)
and then Present (Non_Limited_View (Typ))
then
Set_Etype (Id, Non_Limited_View (Typ));
end if;
end Detect_And_Exchange;
-- Local variables
Formal : Entity_Id;
-- Start of processing for Exchange_Limited_Views
begin
if No (Subp_Id) then
return;
-- Do not process subprogram bodies as they already use the non-
-- limited view of types.
elsif not Ekind_In (Subp_Id, E_Function, E_Procedure) then
return;
end if;
-- Examine all formals and swap views when applicable
Formal := First_Formal (Subp_Id);
while Present (Formal) loop
Detect_And_Exchange (Formal);
Next_Formal (Formal);
end loop;
-- Process the return type of a function
if Ekind (Subp_Id) = E_Function then
Detect_And_Exchange (Subp_Id);
end if;
end Exchange_Limited_Views;
-------------------------------------
-- Is_Private_Concurrent_Primitive --
-------------------------------------
function Is_Private_Concurrent_Primitive
(Subp_Id : Entity_Id) return Boolean
is
Formal_Typ : Entity_Id;
begin
if Present (First_Formal (Subp_Id)) then
Formal_Typ := Etype (First_Formal (Subp_Id));
if Is_Concurrent_Record_Type (Formal_Typ) then
if Is_Class_Wide_Type (Formal_Typ) then
Formal_Typ := Root_Type (Formal_Typ);
end if;
Formal_Typ := Corresponding_Concurrent_Type (Formal_Typ);
end if;
-- The type of the first formal is a concurrent tagged type with
-- a private view.
return
Is_Concurrent_Type (Formal_Typ)
and then Is_Tagged_Type (Formal_Typ)
and then Has_Private_Declaration (Formal_Typ);
end if;
return False;
end Is_Private_Concurrent_Primitive;
----------------------------
-- Set_Trivial_Subprogram --
----------------------------
procedure Set_Trivial_Subprogram (N : Node_Id) is
Nxt : constant Node_Id := Next (N);
begin
Set_Is_Trivial_Subprogram (Body_Id);
if Present (Spec_Id) then
Set_Is_Trivial_Subprogram (Spec_Id);
end if;
if Present (Nxt)
and then Nkind (Nxt) = N_Simple_Return_Statement
and then No (Next (Nxt))
and then Present (Expression (Nxt))
and then Is_Entity_Name (Expression (Nxt))
then
Set_Never_Set_In_Source (Entity (Expression (Nxt)), False);
end if;
end Set_Trivial_Subprogram;
---------------------------------
-- Verify_Overriding_Indicator --
---------------------------------
procedure Verify_Overriding_Indicator is
begin
if Must_Override (Body_Spec) then
if Nkind (Spec_Id) = N_Defining_Operator_Symbol
and then Operator_Matches_Spec (Spec_Id, Spec_Id)
then
null;
elsif not Present (Overridden_Operation (Spec_Id)) then
Error_Msg_NE
("subprogram& is not overriding", Body_Spec, Spec_Id);
end if;
elsif Must_Not_Override (Body_Spec) then
if Present (Overridden_Operation (Spec_Id)) then
Error_Msg_NE
("subprogram& overrides inherited operation",
Body_Spec, Spec_Id);
elsif Nkind (Spec_Id) = N_Defining_Operator_Symbol
and then Operator_Matches_Spec (Spec_Id, Spec_Id)
then
Error_Msg_NE
("subprogram & overrides predefined operator ",
Body_Spec, Spec_Id);
-- If this is not a primitive operation or protected subprogram,
-- then the overriding indicator is altogether illegal.
elsif not Is_Primitive (Spec_Id)
and then Ekind (Scope (Spec_Id)) /= E_Protected_Type
then
Error_Msg_N
("overriding indicator only allowed " &
"if subprogram is primitive",
Body_Spec);
end if;
elsif Style_Check
and then Present (Overridden_Operation (Spec_Id))
then
pragma Assert (Unit_Declaration_Node (Body_Id) = N);
Style.Missing_Overriding (N, Body_Id);
elsif Style_Check
and then Can_Override_Operator (Spec_Id)
and then not Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Spec_Id)))
then
pragma Assert (Unit_Declaration_Node (Body_Id) = N);
Style.Missing_Overriding (N, Body_Id);
end if;
end Verify_Overriding_Indicator;
-- Start of processing for Analyze_Subprogram_Body_Helper
begin
-- Generic subprograms are handled separately. They always have a
-- generic specification. Determine whether current scope has a
-- previous declaration.
-- If the subprogram body is defined within an instance of the same
-- name, the instance appears as a package renaming, and will be hidden
-- within the subprogram.
if Present (Prev_Id)
and then not Is_Overloadable (Prev_Id)
and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
or else Comes_From_Source (Prev_Id))
then
if Is_Generic_Subprogram (Prev_Id) then
Spec_Id := Prev_Id;
Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
Analyze_Generic_Subprogram_Body (N, Spec_Id);
if Nkind (N) = N_Subprogram_Body then
HSS := Handled_Statement_Sequence (N);
Check_Missing_Return;
end if;
return;
else
-- Previous entity conflicts with subprogram name. Attempting to
-- enter name will post error.
Enter_Name (Body_Id);
return;
end if;
-- Non-generic case, find the subprogram declaration, if one was seen,
-- or enter new overloaded entity in the current scope. If the
-- Current_Entity is the Body_Id itself, the unit is being analyzed as
-- part of the context of one of its subunits. No need to redo the
-- analysis.
elsif Prev_Id = Body_Id and then Has_Completion (Body_Id) then
return;
else
Body_Id := Analyze_Subprogram_Specification (Body_Spec);
if Nkind (N) = N_Subprogram_Body_Stub
or else No (Corresponding_Spec (N))
then
if Is_Private_Concurrent_Primitive (Body_Id) then
Spec_Id := Disambiguate_Spec;
else
Spec_Id := Find_Corresponding_Spec (N);
end if;
-- If this is a duplicate body, no point in analyzing it
if Error_Posted (N) then
return;
end if;
-- A subprogram body should cause freezing of its own declaration,
-- but if there was no previous explicit declaration, then the
-- subprogram will get frozen too late (there may be code within
-- the body that depends on the subprogram having been frozen,
-- such as uses of extra formals), so we force it to be frozen
-- here. Same holds if the body and spec are compilation units.
-- Finally, if the return type is an anonymous access to protected
-- subprogram, it must be frozen before the body because its
-- expansion has generated an equivalent type that is used when
-- elaborating the body.
-- An exception in the case of Ada 2012, AI05-177: The bodies
-- created for expression functions do not freeze.
if No (Spec_Id)
and then Nkind (Original_Node (N)) /= N_Expression_Function
then
Freeze_Before (N, Body_Id);
elsif Nkind (Parent (N)) = N_Compilation_Unit then
Freeze_Before (N, Spec_Id);
elsif Is_Access_Subprogram_Type (Etype (Body_Id)) then
Freeze_Before (N, Etype (Body_Id));
end if;
else
Spec_Id := Corresponding_Spec (N);
end if;
end if;
-- Language-defined aspects cannot appear in a subprogram body [stub] if
-- the corresponding spec already has aspects. An exception to this rule
-- are certain user-defined aspects.
if Has_Aspects (N) then
if Present (Spec_Id)
and then not Aspects_On_Body_Or_Stub_OK (N)
-- Do not emit an error on a subprogram body stub that act as
-- its own spec.
and then Nkind (Parent (Parent (Spec_Id))) /= N_Subprogram_Body_Stub
then
Error_Msg_N
("aspect specifications must appear in subprogram declaration",
N);
-- Delay the analysis of aspect specifications that apply to a body
-- stub until the proper body is analyzed. If the corresponding body
-- is missing, the aspects are still analyzed in Analyze_Proper_Body.
elsif Nkind (N) in N_Body_Stub then
null;
else
Analyze_Aspect_Specifications (N, Body_Id);
end if;
end if;
-- Previously we scanned the body to look for nested subprograms, and
-- rejected an inline directive if nested subprograms were present,
-- because the back-end would generate conflicting symbols for the
-- nested bodies. This is now unnecessary.
-- Look ahead to recognize a pragma Inline that appears after the body
Check_Inline_Pragma (Spec_Id);
-- Deal with special case of a fully private operation in the body of
-- the protected type. We must create a declaration for the subprogram,
-- in order to attach the protected subprogram that will be used in
-- internal calls. We exclude compiler generated bodies from the
-- expander since the issue does not arise for those cases.
if No (Spec_Id)
and then Comes_From_Source (N)
and then Is_Protected_Type (Current_Scope)
then
Spec_Id := Build_Private_Protected_Declaration (N);
end if;
-- If a separate spec is present, then deal with freezing issues
if Present (Spec_Id) then
Spec_Decl := Unit_Declaration_Node (Spec_Id);
Verify_Overriding_Indicator;
-- In general, the spec will be frozen when we start analyzing the
-- body. However, for internally generated operations, such as
-- wrapper functions for inherited operations with controlling
-- results, the spec may not have been frozen by the time we expand
-- the freeze actions that include the bodies. In particular, extra
-- formals for accessibility or for return-in-place may need to be
-- generated. Freeze nodes, if any, are inserted before the current
-- body. These freeze actions are also needed in ASIS mode to enable
-- the proper back-annotations.
if not Is_Frozen (Spec_Id)
and then (Expander_Active or ASIS_Mode)
then
-- Force the generation of its freezing node to ensure proper
-- management of access types in the backend.
-- This is definitely needed for some cases, but it is not clear
-- why, to be investigated further???
Set_Has_Delayed_Freeze (Spec_Id);
Freeze_Before (N, Spec_Id);
end if;
end if;
-- Mark presence of postcondition procedure in current scope and mark
-- the procedure itself as needing debug info. The latter is important
-- when analyzing decision coverage (for example, for MC/DC coverage).
if Chars (Body_Id) = Name_uPostconditions then
Set_Has_Postconditions (Current_Scope);
Set_Debug_Info_Needed (Body_Id);
end if;
-- Place subprogram on scope stack, and make formals visible. If there
-- is a spec, the visible entity remains that of the spec.
if Present (Spec_Id) then
Generate_Reference (Spec_Id, Body_Id, 'b', Set_Ref => False);
if Is_Child_Unit (Spec_Id) then
Generate_Reference (Spec_Id, Scope (Spec_Id), 'k', False);
end if;
if Style_Check then
Style.Check_Identifier (Body_Id, Spec_Id);
end if;
Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
if Is_Abstract_Subprogram (Spec_Id) then
Error_Msg_N ("an abstract subprogram cannot have a body", N);
return;
else
Set_Convention (Body_Id, Convention (Spec_Id));
Set_Has_Completion (Spec_Id);
if Is_Protected_Type (Scope (Spec_Id)) then
Prot_Typ := Scope (Spec_Id);
end if;
-- If this is a body generated for a renaming, do not check for
-- full conformance. The check is redundant, because the spec of
-- the body is a copy of the spec in the renaming declaration,
-- and the test can lead to spurious errors on nested defaults.
if Present (Spec_Decl)
and then not Comes_From_Source (N)
and then
(Nkind (Original_Node (Spec_Decl)) =
N_Subprogram_Renaming_Declaration
or else (Present (Corresponding_Body (Spec_Decl))
and then
Nkind (Unit_Declaration_Node
(Corresponding_Body (Spec_Decl))) =
N_Subprogram_Renaming_Declaration))
then
Conformant := True;
-- Conversely, the spec may have been generated for specless body
-- with an inline pragma.
elsif Comes_From_Source (N)
and then not Comes_From_Source (Spec_Id)
and then Has_Pragma_Inline (Spec_Id)
then
Conformant := True;
else
Check_Conformance
(Body_Id, Spec_Id,
Fully_Conformant, True, Conformant, Body_Id);
end if;
-- If the body is not fully conformant, we have to decide if we
-- should analyze it or not. If it has a really messed up profile
-- then we probably should not analyze it, since we will get too
-- many bogus messages.
-- Our decision is to go ahead in the non-fully conformant case
-- only if it is at least mode conformant with the spec. Note
-- that the call to Check_Fully_Conformant has issued the proper
-- error messages to complain about the lack of conformance.
if not Conformant
and then not Mode_Conformant (Body_Id, Spec_Id)
then
return;
end if;
end if;
if Spec_Id /= Body_Id then
Reference_Body_Formals (Spec_Id, Body_Id);
end if;
if Nkind (N) = N_Subprogram_Body_Stub then
Set_Corresponding_Spec_Of_Stub (N, Spec_Id);
-- Regular body
else
Set_Corresponding_Spec (N, Spec_Id);
-- Ada 2005 (AI-345): If the operation is a primitive operation
-- of a concurrent type, the type of the first parameter has been
-- replaced with the corresponding record, which is the proper
-- run-time structure to use. However, within the body there may
-- be uses of the formals that depend on primitive operations
-- of the type (in particular calls in prefixed form) for which
-- we need the original concurrent type. The operation may have
-- several controlling formals, so the replacement must be done
-- for all of them.
if Comes_From_Source (Spec_Id)
and then Present (First_Entity (Spec_Id))
and then Ekind (Etype (First_Entity (Spec_Id))) = E_Record_Type
and then Is_Tagged_Type (Etype (First_Entity (Spec_Id)))
and then Present (Interfaces (Etype (First_Entity (Spec_Id))))
and then Present (Corresponding_Concurrent_Type
(Etype (First_Entity (Spec_Id))))
then
declare
Typ : constant Entity_Id := Etype (First_Entity (Spec_Id));
Form : Entity_Id;
begin
Form := First_Formal (Spec_Id);
while Present (Form) loop
if Etype (Form) = Typ then
Set_Etype (Form, Corresponding_Concurrent_Type (Typ));
end if;
Next_Formal (Form);
end loop;
end;
end if;
-- Make the formals visible, and place subprogram on scope stack.
-- This is also the point at which we set Last_Real_Spec_Entity
-- to mark the entities which will not be moved to the body.
Install_Formals (Spec_Id);
Last_Real_Spec_Entity := Last_Entity (Spec_Id);
-- Within an instance, add local renaming declarations so that
-- gdb can retrieve the values of actuals more easily. This is
-- only relevant if generating code (and indeed we definitely
-- do not want these definitions -gnatc mode, because that would
-- confuse ASIS).
if Is_Generic_Instance (Spec_Id)
and then Is_Wrapper_Package (Current_Scope)
and then Expander_Active
then
Build_Subprogram_Instance_Renamings (N, Current_Scope);
end if;
Push_Scope (Spec_Id);
-- Make sure that the subprogram is immediately visible. For
-- child units that have no separate spec this is indispensable.
-- Otherwise it is safe albeit redundant.
Set_Is_Immediately_Visible (Spec_Id);
end if;
Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
Set_Contract (Body_Id, Empty);
Set_Ekind (Body_Id, E_Subprogram_Body);
Set_Scope (Body_Id, Scope (Spec_Id));
Set_Is_Obsolescent (Body_Id, Is_Obsolescent (Spec_Id));
-- Case of subprogram body with no previous spec
else
-- Check for style warning required
if Style_Check
-- Only apply check for source level subprograms for which checks
-- have not been suppressed.
and then Comes_From_Source (Body_Id)
and then not Suppress_Style_Checks (Body_Id)
-- No warnings within an instance
and then not In_Instance
-- No warnings for expression functions
and then Nkind (Original_Node (N)) /= N_Expression_Function
then
Style.Body_With_No_Spec (N);
end if;
New_Overloaded_Entity (Body_Id);
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Acts_As_Spec (N);
Generate_Definition (Body_Id);
Set_Contract (Body_Id, Make_Contract (Sloc (Body_Id)));
Generate_Reference
(Body_Id, Body_Id, 'b', Set_Ref => False, Force => True);
Install_Formals (Body_Id);
Push_Scope (Body_Id);
end if;
-- For stubs and bodies with no previous spec, generate references to
-- formals.
Generate_Reference_To_Formals (Body_Id);
end if;
-- If the return type is an anonymous access type whose designated type
-- is the limited view of a class-wide type and the non-limited view is
-- available, update the return type accordingly.
if Ada_Version >= Ada_2005 and then Comes_From_Source (N) then
declare
Etyp : Entity_Id;
Rtyp : Entity_Id;
begin
Rtyp := Etype (Current_Scope);
if Ekind (Rtyp) = E_Anonymous_Access_Type then
Etyp := Directly_Designated_Type (Rtyp);
if Is_Class_Wide_Type (Etyp) and then From_With_Type (Etyp) then
Set_Directly_Designated_Type
(Etype (Current_Scope), Available_View (Etyp));
end if;
end if;
end;
end if;
-- If this is the proper body of a stub, we must verify that the stub
-- conforms to the body, and to the previous spec if one was present.
-- We know already that the body conforms to that spec. This test is
-- only required for subprograms that come from source.
if Nkind (Parent (N)) = N_Subunit
and then Comes_From_Source (N)
and then not Error_Posted (Body_Id)
and then Nkind (Corresponding_Stub (Parent (N))) =
N_Subprogram_Body_Stub
then
declare
Old_Id : constant Entity_Id :=
Defining_Entity
(Specification (Corresponding_Stub (Parent (N))));
Conformant : Boolean := False;
begin
if No (Spec_Id) then
Check_Fully_Conformant (Body_Id, Old_Id);
else
Check_Conformance
(Body_Id, Old_Id, Fully_Conformant, False, Conformant);
if not Conformant then
-- The stub was taken to be a new declaration. Indicate that
-- it lacks a body.
Set_Has_Completion (Old_Id, False);
end if;
end if;
end;
end if;
Set_Has_Completion (Body_Id);
Check_Eliminated (Body_Id);
if Nkind (N) = N_Subprogram_Body_Stub then
return;
end if;
-- Handle frontend inlining. There is no need to prepare us for inlining
-- if we will not generate the code.
-- Old semantics
if not Debug_Flag_Dot_K then
if Present (Spec_Id)
and then Expander_Active
and then
(Has_Pragma_Inline_Always (Spec_Id)
or else (Has_Pragma_Inline (Spec_Id) and Front_End_Inlining))
then
Build_Body_To_Inline (N, Spec_Id);
end if;
-- New semantics
elsif Expander_Active
and then Serious_Errors_Detected = 0
and then Present (Spec_Id)
and then Has_Pragma_Inline (Spec_Id)
then
Check_And_Build_Body_To_Inline (N, Spec_Id, Body_Id);
end if;
-- Ada 2005 (AI-262): In library subprogram bodies, after the analysis
-- of the specification we have to install the private withed units.
-- This holds for child units as well.
if Is_Compilation_Unit (Body_Id)
or else Nkind (Parent (N)) = N_Compilation_Unit
then
Install_Private_With_Clauses (Body_Id);
end if;
Check_Anonymous_Return;
-- Set the Protected_Formal field of each extra formal of the protected
-- subprogram to reference the corresponding extra formal of the
-- subprogram that implements it. For regular formals this occurs when
-- the protected subprogram's declaration is expanded, but the extra
-- formals don't get created until the subprogram is frozen. We need to
-- do this before analyzing the protected subprogram's body so that any
-- references to the original subprogram's extra formals will be changed
-- refer to the implementing subprogram's formals (see Expand_Formal).
if Present (Spec_Id)
and then Is_Protected_Type (Scope (Spec_Id))
and then Present (Protected_Body_Subprogram (Spec_Id))
then
declare
Impl_Subp : constant Entity_Id :=
Protected_Body_Subprogram (Spec_Id);
Prot_Ext_Formal : Entity_Id := Extra_Formals (Spec_Id);
Impl_Ext_Formal : Entity_Id := Extra_Formals (Impl_Subp);
begin
while Present (Prot_Ext_Formal) loop
pragma Assert (Present (Impl_Ext_Formal));
Set_Protected_Formal (Prot_Ext_Formal, Impl_Ext_Formal);
Next_Formal_With_Extras (Prot_Ext_Formal);
Next_Formal_With_Extras (Impl_Ext_Formal);
end loop;
end;
end if;
-- Now we can go on to analyze the body
HSS := Handled_Statement_Sequence (N);
Set_Actual_Subtypes (N, Current_Scope);
-- Deal with preconditions and postconditions. In formal verification
-- mode, we keep pre- and postconditions attached to entities rather
-- than inserted in the code, in order to facilitate a distinct
-- treatment for them.
if not SPARK_Mode then
Process_PPCs (N, Spec_Id, Body_Id);
end if;
-- Add a declaration for the Protection object, renaming declarations
-- for discriminals and privals and finally a declaration for the entry
-- family index (if applicable). This form of early expansion is done
-- when the Expander is active because Install_Private_Data_Declarations
-- references entities which were created during regular expansion. The
-- body may be the rewritting of an expression function, and we need to
-- verify that the original node is in the source.
if Full_Expander_Active
and then Comes_From_Source (Original_Node (N))
and then Present (Prot_Typ)
and then Present (Spec_Id)
and then not Is_Eliminated (Spec_Id)
then
Install_Private_Data_Declarations
(Sloc (N), Spec_Id, Prot_Typ, N, Declarations (N));
end if;
-- Ada 2012 (AI05-0151): Incomplete types coming from a limited context
-- may now appear in parameter and result profiles. Since the analysis
-- of a subprogram body may use the parameter and result profile of the
-- spec, swap any limited views with their non-limited counterpart.
if Ada_Version >= Ada_2012 then
Exchange_Limited_Views (Spec_Id);
end if;
-- Analyze the declarations (this call will analyze the precondition
-- Check pragmas we prepended to the list, as well as the declaration
-- of the _Postconditions procedure).
Analyze_Declarations (Declarations (N));
-- Check completion, and analyze the statements
Check_Completion;
Inspect_Deferred_Constant_Completion (Declarations (N));
Analyze (HSS);
-- Deal with end of scope processing for the body
Process_End_Label (HSS, 't', Current_Scope);
End_Scope;
Check_Subprogram_Order (N);
Set_Analyzed (Body_Id);
-- If we have a separate spec, then the analysis of the declarations
-- caused the entities in the body to be chained to the spec id, but
-- we want them chained to the body id. Only the formal parameters
-- end up chained to the spec id in this case.
if Present (Spec_Id) then
-- We must conform to the categorization of our spec
Validate_Categorization_Dependency (N, Spec_Id);
-- And if this is a child unit, the parent units must conform
if Is_Child_Unit (Spec_Id) then
Validate_Categorization_Dependency
(Unit_Declaration_Node (Spec_Id), Spec_Id);
end if;
-- Here is where we move entities from the spec to the body
-- Case where there are entities that stay with the spec
if Present (Last_Real_Spec_Entity) then
-- No body entities (happens when the only real spec entities come
-- from precondition and postcondition pragmas).
if No (Last_Entity (Body_Id)) then
Set_First_Entity
(Body_Id, Next_Entity (Last_Real_Spec_Entity));
-- Body entities present (formals), so chain stuff past them
else
Set_Next_Entity
(Last_Entity (Body_Id), Next_Entity (Last_Real_Spec_Entity));
end if;
Set_Next_Entity (Last_Real_Spec_Entity, Empty);
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_Last_Entity (Spec_Id, Last_Real_Spec_Entity);
-- Case where there are no spec entities, in this case there can be
-- no body entities either, so just move everything.
else
pragma Assert (No (Last_Entity (Body_Id)));
Set_First_Entity (Body_Id, First_Entity (Spec_Id));
Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
Set_First_Entity (Spec_Id, Empty);
Set_Last_Entity (Spec_Id, Empty);
end if;
end if;
Check_Missing_Return;
-- Now we are going to check for variables that are never modified in
-- the body of the procedure. But first we deal with a special case
-- where we want to modify this check. If the body of the subprogram
-- starts with a raise statement or its equivalent, or if the body
-- consists entirely of a null statement, then it is pretty obvious
-- that it is OK to not reference the parameters. For example, this
-- might be the following common idiom for a stubbed function:
-- statement of the procedure raises an exception. In particular this
-- deals with the common idiom of a stubbed function, which might
-- appear as something like:
-- function F (A : Integer) return Some_Type;
-- X : Some_Type;
-- begin
-- raise Program_Error;
-- return X;
-- end F;
-- Here the purpose of X is simply to satisfy the annoying requirement
-- in Ada that there be at least one return, and we certainly do not
-- want to go posting warnings on X that it is not initialized! On
-- the other hand, if X is entirely unreferenced that should still
-- get a warning.
-- What we do is to detect these cases, and if we find them, flag the
-- subprogram as being Is_Trivial_Subprogram and then use that flag to
-- suppress unwanted warnings. For the case of the function stub above
-- we have a special test to set X as apparently assigned to suppress
-- the warning.
declare
Stm : Node_Id;
begin
-- Skip initial labels (for one thing this occurs when we are in
-- front end ZCX mode, but in any case it is irrelevant), and also
-- initial Push_xxx_Error_Label nodes, which are also irrelevant.
Stm := First (Statements (HSS));
while Nkind (Stm) = N_Label
or else Nkind (Stm) in N_Push_xxx_Label
loop
Next (Stm);
end loop;
-- Do the test on the original statement before expansion
declare
Ostm : constant Node_Id := Original_Node (Stm);
begin
-- If explicit raise statement, turn on flag
if Nkind (Ostm) = N_Raise_Statement then
Set_Trivial_Subprogram (Stm);
-- If null statement, and no following statements, turn on flag
elsif Nkind (Stm) = N_Null_Statement
and then Comes_From_Source (Stm)
and then No (Next (Stm))
then
Set_Trivial_Subprogram (Stm);
-- Check for explicit call cases which likely raise an exception
elsif Nkind (Ostm) = N_Procedure_Call_Statement then
if Is_Entity_Name (Name (Ostm)) then
declare
Ent : constant Entity_Id := Entity (Name (Ostm));
begin
-- If the procedure is marked No_Return, then likely it
-- raises an exception, but in any case it is not coming
-- back here, so turn on the flag.
if Present (Ent)
and then Ekind (Ent) = E_Procedure
and then No_Return (Ent)
then
Set_Trivial_Subprogram (Stm);
end if;
end;
end if;
end if;
end;
end;
-- Check for variables that are never modified
declare
E1, E2 : Entity_Id;
begin
-- If there is a separate spec, then transfer Never_Set_In_Source
-- flags from out parameters to the corresponding entities in the
-- body. The reason we do that is we want to post error flags on
-- the body entities, not the spec entities.
if Present (Spec_Id) then
E1 := First_Entity (Spec_Id);
while Present (E1) loop
if Ekind (E1) = E_Out_Parameter then
E2 := First_Entity (Body_Id);
while Present (E2) loop
exit when Chars (E1) = Chars (E2);
Next_Entity (E2);
end loop;
if Present (E2) then
Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
end if;
end if;
Next_Entity (E1);
end loop;
end if;
-- Check references in body
Check_References (Body_Id);
end;
end Analyze_Subprogram_Body_Helper;
---------------------------------
-- Analyze_Subprogram_Contract --
---------------------------------
procedure Analyze_Subprogram_Contract (Subp : Entity_Id) is
Result_Seen : Boolean := False;
-- A flag which keeps track of whether at least one postcondition or
-- contract-case mentions attribute 'Result (set True if so).
procedure Check_Result_And_Post_State
(Prag : Node_Id;
Error_Nod : in out Node_Id);
-- Determine whether pragma Prag mentions attribute 'Result and whether
-- the pragma contains an expression that evaluates differently in pre-
-- and post-state. Prag is a postcondition or a contract-cases pragma.
-- Error_Nod denotes the proper error node.
---------------------------------
-- Check_Result_And_Post_State --
---------------------------------
procedure Check_Result_And_Post_State
(Prag : Node_Id;
Error_Nod : in out Node_Id)
is
procedure Check_Expression (Expr : Node_Id);
-- Perform the 'Result and post-state checks on a given expression
function Is_Function_Result (N : Node_Id) return Traverse_Result;
-- Attempt to find attribute 'Result in a subtree denoted by N
function Is_Trivial_Boolean (N : Node_Id) return Boolean;
-- Determine whether source node N denotes "True" or "False"
function Mentions_Post_State (N : Node_Id) return Boolean;
-- Determine whether a subtree denoted by N mentions any construct
-- that denotes a post-state.
procedure Check_Function_Result is
new Traverse_Proc (Is_Function_Result);
----------------------
-- Check_Expression --
----------------------
procedure Check_Expression (Expr : Node_Id) is
begin
if not Is_Trivial_Boolean (Expr) then
Check_Function_Result (Expr);
if not Mentions_Post_State (Expr) then
if Pragma_Name (Prag) = Name_Contract_Cases then
Error_Msg_N
("contract case refers only to pre-state?T?", Expr);
else
Error_Msg_N
("postcondition refers only to pre-state?T?", Prag);
end if;
end if;
end if;
end Check_Expression;
------------------------
-- Is_Function_Result --
------------------------
function Is_Function_Result (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) = Name_Result
then
Result_Seen := True;
return Abandon;
-- Continue the traversal
else
return OK;
end if;
end Is_Function_Result;
------------------------
-- Is_Trivial_Boolean --
------------------------
function Is_Trivial_Boolean (N : Node_Id) return Boolean is
begin
return
Comes_From_Source (N)
and then Is_Entity_Name (N)
and then (Entity (N) = Standard_True
or else Entity (N) = Standard_False);
end Is_Trivial_Boolean;
-------------------------
-- Mentions_Post_State --
-------------------------
function Mentions_Post_State (N : Node_Id) return Boolean is
Post_State_Seen : Boolean := False;
function Is_Post_State (N : Node_Id) return Traverse_Result;
-- Attempt to find a construct that denotes a post-state. If this
-- is the case, set flag Post_State_Seen.
-------------------
-- Is_Post_State --
-------------------
function Is_Post_State (N : Node_Id) return Traverse_Result is
Ent : Entity_Id;
begin
if Nkind_In (N, N_Explicit_Dereference, N_Function_Call) then
Post_State_Seen := True;
return Abandon;
elsif Nkind_In (N, N_Expanded_Name, N_Identifier) then
Ent := Entity (N);
if No (Ent) or else Ekind (Ent) in Assignable_Kind then
Post_State_Seen := True;
return Abandon;
end if;
elsif Nkind (N) = N_Attribute_Reference then
if Attribute_Name (N) = Name_Old then
return Skip;
elsif Attribute_Name (N) = Name_Result then
Post_State_Seen := True;
return Abandon;
end if;
end if;
return OK;
end Is_Post_State;
procedure Find_Post_State is new Traverse_Proc (Is_Post_State);
-- Start of processing for Mentions_Post_State
begin
Find_Post_State (N);
return Post_State_Seen;
end Mentions_Post_State;
-- Local variables
Expr : constant Node_Id :=
Expression (First (Pragma_Argument_Associations (Prag)));
Nam : constant Name_Id := Pragma_Name (Prag);
CCase : Node_Id;
-- Start of processing for Check_Result_And_Post_State
begin
if No (Error_Nod) then
Error_Nod := Prag;
end if;
-- Examine all consequences
if Nam = Name_Contract_Cases then
CCase := First (Component_Associations (Expr));
while Present (CCase) loop
Check_Expression (Expression (CCase));
Next (CCase);
end loop;
-- Examine the expression of a postcondition
else
pragma Assert (Nam = Name_Postcondition);
Check_Expression (Expr);
end if;
end Check_Result_And_Post_State;
-- Local variables
Items : constant Node_Id := Contract (Subp);
Error_CCase : Node_Id;
Error_Post : Node_Id;
Prag : Node_Id;
-- Start of processing for Analyze_Subprogram_Contract
begin
Error_CCase := Empty;
Error_Post := Empty;
if Present (Items) then
-- Analyze pre- and postconditions
Prag := Pre_Post_Conditions (Items);
while Present (Prag) loop
Analyze_PPC_In_Decl_Part (Prag, Subp);
-- Verify whether a postcondition mentions attribute 'Result and
-- its expression introduces a post-state.
if Warn_On_Suspicious_Contract
and then Pragma_Name (Prag) = Name_Postcondition
then
Check_Result_And_Post_State (Prag, Error_Post);
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze contract-cases and test-cases
Prag := Contract_Test_Cases (Items);
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Contract_Cases then
Analyze_Contract_Cases_In_Decl_Part (Prag);
-- Verify whether contract-cases mention attribute 'Result and
-- its expression introduces a post-state. Perform the check
-- only when the pragma is legal.
if Warn_On_Suspicious_Contract
and then not Error_Posted (Prag)
then
Check_Result_And_Post_State (Prag, Error_CCase);
end if;
else
pragma Assert (Pragma_Name (Prag) = Name_Test_Case);
Analyze_Test_Case_In_Decl_Part (Prag, Subp);
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Analyze classification pragmas
Prag := Classifications (Contract (Subp));
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Depends then
Analyze_Depends_In_Decl_Part (Prag);
else
pragma Assert (Pragma_Name (Prag) = Name_Global);
Analyze_Global_In_Decl_Part (Prag);
end if;
Prag := Next_Pragma (Prag);
end loop;
end if;
-- Emit an error when none of the postconditions or contract-cases
-- mention attribute 'Result in the context of a function.
if Warn_On_Suspicious_Contract
and then Ekind_In (Subp, E_Function, E_Generic_Function)
and then not Result_Seen
then
if Present (Error_Post) and then Present (Error_CCase) then
Error_Msg_N
("neither function postcondition nor contract cases mention "
& "result?T?", Error_Post);
elsif Present (Error_Post) then
Error_Msg_N
("function postcondition does not mention result?T?",
Error_Post);
elsif Present (Error_CCase) then
Error_Msg_N
("contract cases do not mention result?T?", Error_CCase);
end if;
end if;
end Analyze_Subprogram_Contract;
------------------------------------
-- Analyze_Subprogram_Declaration --
------------------------------------
procedure Analyze_Subprogram_Declaration (N : Node_Id) is
Scop : constant Entity_Id := Current_Scope;
Designator : Entity_Id;
Is_Completion : Boolean;
-- Indicates whether a null procedure declaration is a completion
begin
-- Null procedures are not allowed in SPARK
if Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
Check_SPARK_Restriction ("null procedure is not allowed", N);
if Is_Protected_Type (Current_Scope) then
Error_Msg_N ("protected operation cannot be a null procedure", N);
end if;
Analyze_Null_Procedure (N, Is_Completion);
if Is_Completion then
-- The null procedure acts as a body, nothing further is needed.
return;
end if;
end if;
Designator := Analyze_Subprogram_Specification (Specification (N));
-- A reference may already have been generated for the unit name, in
-- which case the following call is redundant. However it is needed for
-- declarations that are the rewriting of an expression function.
Generate_Definition (Designator);
if Debug_Flag_C then
Write_Str ("==> subprogram spec ");
Write_Name (Chars (Designator));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
Indent;
end if;
Validate_RCI_Subprogram_Declaration (N);
New_Overloaded_Entity (Designator);
Check_Delayed_Subprogram (Designator);
-- If the type of the first formal of the current subprogram is a
-- non-generic tagged private type, mark the subprogram as being a
-- private primitive. Ditto if this is a function with controlling
-- result, and the return type is currently private. In both cases,
-- the type of the controlling argument or result must be in the
-- current scope for the operation to be primitive.
if Has_Controlling_Result (Designator)
and then Is_Private_Type (Etype (Designator))
and then Scope (Etype (Designator)) = Current_Scope
and then not Is_Generic_Actual_Type (Etype (Designator))
then
Set_Is_Private_Primitive (Designator);
elsif Present (First_Formal (Designator)) then
declare
Formal_Typ : constant Entity_Id :=
Etype (First_Formal (Designator));
begin
Set_Is_Private_Primitive (Designator,
Is_Tagged_Type (Formal_Typ)
and then Scope (Formal_Typ) = Current_Scope
and then Is_Private_Type (Formal_Typ)
and then not Is_Generic_Actual_Type (Formal_Typ));
end;
end if;
-- Ada 2005 (AI-251): Abstract interface primitives must be abstract
-- or null.
if Ada_Version >= Ada_2005
and then Comes_From_Source (N)
and then Is_Dispatching_Operation (Designator)
then
declare
E : Entity_Id;
Etyp : Entity_Id;
begin
if Has_Controlling_Result (Designator) then
Etyp := Etype (Designator);
else
E := First_Entity (Designator);
while Present (E)
and then Is_Formal (E)
and then not Is_Controlling_Formal (E)
loop
Next_Entity (E);
end loop;
Etyp := Etype (E);
end if;
if Is_Access_Type (Etyp) then
Etyp := Directly_Designated_Type (Etyp);
end if;
if Is_Interface (Etyp)
and then not Is_Abstract_Subprogram (Designator)
and then not (Ekind (Designator) = E_Procedure
and then Null_Present (Specification (N)))
then
Error_Msg_Name_1 := Chars (Defining_Entity (N));
-- Specialize error message based on procedures vs. functions,
-- since functions can't be null subprograms.
if Ekind (Designator) = E_Procedure then
Error_Msg_N
("interface procedure % must be abstract or null", N);
else
Error_Msg_N ("interface function % must be abstract", N);
end if;
end if;
end;
end if;
-- What is the following code for, it used to be
-- ??? Set_Suppress_Elaboration_Checks
-- ??? (Designator, Elaboration_Checks_Suppressed (Designator));
-- The following seems equivalent, but a bit dubious
if Elaboration_Checks_Suppressed (Designator) then
Set_Kill_Elaboration_Checks (Designator);
end if;
if Scop /= Standard_Standard and then not Is_Child_Unit (Designator) then
Set_Categorization_From_Scope (Designator, Scop);
else
-- For a compilation unit, check for library-unit pragmas
Push_Scope (Designator);
Set_Categorization_From_Pragmas (N);
Validate_Categorization_Dependency (N, Designator);
Pop_Scope;
end if;
-- For a compilation unit, set body required. This flag will only be
-- reset if a valid Import or Interface pragma is processed later on.
if Nkind (Parent (N)) = N_Compilation_Unit then
Set_Body_Required (Parent (N), True);
if Ada_Version >= Ada_2005
and then Nkind (Specification (N)) = N_Procedure_Specification
and then Null_Present (Specification (N))
then
Error_Msg_N
("null procedure cannot be declared at library level", N);
end if;
end if;
Generate_Reference_To_Formals (Designator);
Check_Eliminated (Designator);
if Debug_Flag_C then
Outdent;
Write_Str ("<== subprogram spec ");
Write_Name (Chars (Designator));
Write_Str (" from ");
Write_Location (Sloc (N));
Write_Eol;
end if;
if Is_Protected_Type (Current_Scope) then
-- Indicate that this is a protected operation, because it may be
-- used in subsequent declarations within the protected type.
Set_Convention (Designator, Convention_Protected);
end if;
List_Inherited_Pre_Post_Aspects (Designator);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Designator);
end if;
end Analyze_Subprogram_Declaration;
--------------------------------------
-- Analyze_Subprogram_Specification --
--------------------------------------
-- Reminder: N here really is a subprogram specification (not a subprogram
-- declaration). This procedure is called to analyze the specification in
-- both subprogram bodies and subprogram declarations (specs).
function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id is
Designator : constant Entity_Id := Defining_Entity (N);
Formals : constant List_Id := Parameter_Specifications (N);
-- Start of processing for Analyze_Subprogram_Specification
begin
-- User-defined operator is not allowed in SPARK, except as a renaming
if Nkind (Defining_Unit_Name (N)) = N_Defining_Operator_Symbol
and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
then
Check_SPARK_Restriction ("user-defined operator is not allowed", N);
end if;
-- Proceed with analysis. Do not emit a cross-reference entry if the
-- specification comes from an expression function, because it may be
-- the completion of a previous declaration. It is is not, the cross-
-- reference entry will be emitted for the new subprogram declaration.
if Nkind (Parent (N)) /= N_Expression_Function then
Generate_Definition (Designator);
end if;
Set_Contract (Designator, Make_Contract (Sloc (Designator)));
if Nkind (N) = N_Function_Specification then
Set_Ekind (Designator, E_Function);
Set_Mechanism (Designator, Default_Mechanism);
else
Set_Ekind (Designator, E_Procedure);
Set_Etype (Designator, Standard_Void_Type);
end if;
-- Introduce new scope for analysis of the formals and the return type
Set_Scope (Designator, Current_Scope);
if Present (Formals) then
Push_Scope (Designator);
Process_Formals (Formals, N);
-- Check dimensions in N for formals with default expression
Analyze_Dimension_Formals (N, Formals);
-- Ada 2005 (AI-345): If this is an overriding operation of an
-- inherited interface operation, and the controlling type is
-- a synchronized type, replace the type with its corresponding
-- record, to match the proper signature of an overriding operation.
-- Same processing for an access parameter whose designated type is
-- derived from a synchronized interface.
if Ada_Version >= Ada_2005 then
declare
Formal : Entity_Id;
Formal_Typ : Entity_Id;
Rec_Typ : Entity_Id;
Desig_Typ : Entity_Id;
begin
Formal := First_Formal (Designator);
while Present (Formal) loop
Formal_Typ := Etype (Formal);
if Is_Concurrent_Type (Formal_Typ)
and then Present (Corresponding_Record_Type (Formal_Typ))
then
Rec_Typ := Corresponding_Record_Type (Formal_Typ);
if Present (Interfaces (Rec_Typ)) then
Set_Etype (Formal, Rec_Typ);
end if;
elsif Ekind (Formal_Typ) = E_Anonymous_Access_Type then
Desig_Typ := Designated_Type (Formal_Typ);
if Is_Concurrent_Type (Desig_Typ)
and then Present (Corresponding_Record_Type (Desig_Typ))
then
Rec_Typ := Corresponding_Record_Type (Desig_Typ);
if Present (Interfaces (Rec_Typ)) then
Set_Directly_Designated_Type (Formal_Typ, Rec_Typ);
end if;
end if;
end if;
Next_Formal (Formal);
end loop;
end;
end if;
End_Scope;
-- The subprogram scope is pushed and popped around the processing of
-- the return type for consistency with call above to Process_Formals
-- (which itself can call Analyze_Return_Type), and to ensure that any
-- itype created for the return type will be associated with the proper
-- scope.
elsif Nkind (N) = N_Function_Specification then
Push_Scope (Designator);
Analyze_Return_Type (N);
End_Scope;
end if;
-- Function case
if Nkind (N) = N_Function_Specification then
-- Deal with operator symbol case
if Nkind (Designator) = N_Defining_Operator_Symbol then
Valid_Operator_Definition (Designator);
end if;
May_Need_Actuals (Designator);
-- Ada 2005 (AI-251): If the return type is abstract, verify that
-- the subprogram is abstract also. This does not apply to renaming
-- declarations, where abstractness is inherited, and to subprogram
-- bodies generated for stream operations, which become renamings as
-- bodies.
-- In case of primitives associated with abstract interface types
-- the check is applied later (see Analyze_Subprogram_Declaration).
if not Nkind_In (Original_Node (Parent (N)),
N_Subprogram_Renaming_Declaration,
N_Abstract_Subprogram_Declaration,
N_Formal_Abstract_Subprogram_Declaration)
then
if Is_Abstract_Type (Etype (Designator))
and then not Is_Interface (Etype (Designator))
then
Error_Msg_N
("function that returns abstract type must be abstract", N);
-- Ada 2012 (AI-0073): Extend this test to subprograms with an
-- access result whose designated type is abstract.
elsif Nkind (Result_Definition (N)) = N_Access_Definition
and then
not Is_Class_Wide_Type (Designated_Type (Etype (Designator)))
and then Is_Abstract_Type (Designated_Type (Etype (Designator)))
and then Ada_Version >= Ada_2012
then
Error_Msg_N ("function whose access result designates "
& "abstract type must be abstract", N);
end if;
end if;
end if;
return Designator;
end Analyze_Subprogram_Specification;
--------------------------
-- Build_Body_To_Inline --
--------------------------
procedure Build_Body_To_Inline (N : Node_Id; Subp : Entity_Id) is
Decl : constant Node_Id := Unit_Declaration_Node (Subp);
Original_Body : Node_Id;
Body_To_Analyze : Node_Id;
Max_Size : constant := 10;
Stat_Count : Integer := 0;
function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
-- Check for declarations that make inlining not worthwhile
function Has_Excluded_Statement (Stats : List_Id) return Boolean;
-- Check for statements that make inlining not worthwhile: any tasking
-- statement, nested at any level. Keep track of total number of
-- elementary statements, as a measure of acceptable size.
function Has_Pending_Instantiation return Boolean;
-- If some enclosing body contains instantiations that appear before the
-- corresponding generic body, the enclosing body has a freeze node so
-- that it can be elaborated after the generic itself. This might
-- conflict with subsequent inlinings, so that it is unsafe to try to
-- inline in such a case.
function Has_Single_Return return Boolean;
-- In general we cannot inline functions that return unconstrained type.
-- However, we can handle such functions if all return statements return
-- a local variable that is the only declaration in the body of the
-- function. In that case the call can be replaced by that local
-- variable as is done for other inlined calls.
procedure Remove_Pragmas;
-- A pragma Unreferenced or pragma Unmodified that mentions a formal
-- parameter has no meaning when the body is inlined and the formals
-- are rewritten. Remove it from body to inline. The analysis of the
-- non-inlined body will handle the pragma properly.
function Uses_Secondary_Stack (Bod : Node_Id) return Boolean;
-- If the body of the subprogram includes a call that returns an
-- unconstrained type, the secondary stack is involved, and it
-- is not worth inlining.
------------------------------
-- Has_Excluded_Declaration --
------------------------------
function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
D : Node_Id;
function Is_Unchecked_Conversion (D : Node_Id) return Boolean;
-- Nested subprograms make a given body ineligible for inlining, but
-- we make an exception for instantiations of unchecked conversion.
-- The body has not been analyzed yet, so check the name, and verify
-- that the visible entity with that name is the predefined unit.
-----------------------------
-- Is_Unchecked_Conversion --
-----------------------------
function Is_Unchecked_Conversion (D : Node_Id) return Boolean is
Id : constant Node_Id := Name (D);
Conv : Entity_Id;
begin
if Nkind (Id) = N_Identifier
and then Chars (Id) = Name_Unchecked_Conversion
then
Conv := Current_Entity (Id);
elsif Nkind_In (Id, N_Selected_Component, N_Expanded_Name)
and then Chars (Selector_Name (Id)) = Name_Unchecked_Conversion
then
Conv := Current_Entity (Selector_Name (Id));
else
return False;
end if;
return Present (Conv)
and then Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Conv)))
and then Is_Intrinsic_Subprogram (Conv);
end Is_Unchecked_Conversion;
-- Start of processing for Has_Excluded_Declaration
begin
D := First (Decls);
while Present (D) loop
if (Nkind (D) = N_Function_Instantiation
and then not Is_Unchecked_Conversion (D))
or else Nkind_In (D, N_Protected_Type_Declaration,
N_Package_Declaration,
N_Package_Instantiation,
N_Subprogram_Body,
N_Procedure_Instantiation,
N_Task_Type_Declaration)
then
Cannot_Inline
("cannot inline & (non-allowed declaration)?", D, Subp);
return True;
end if;
Next (D);
end loop;
return False;
end Has_Excluded_Declaration;
----------------------------
-- Has_Excluded_Statement --
----------------------------
function Has_Excluded_Statement (Stats : List_Id) return Boolean is
S : Node_Id;
E : Node_Id;
begin
S := First (Stats);
while Present (S) loop
Stat_Count := Stat_Count + 1;
if Nkind_In (S, N_Abort_Statement,
N_Asynchronous_Select,
N_Conditional_Entry_Call,
N_Delay_Relative_Statement,
N_Delay_Until_Statement,
N_Selective_Accept,
N_Timed_Entry_Call)
then
Cannot_Inline
("cannot inline & (non-allowed statement)?", S, Subp);
return True;
elsif Nkind (S) = N_Block_Statement then
if Present (Declarations (S))
and then Has_Excluded_Declaration (Declarations (S))
then
return True;
elsif Present (Handled_Statement_Sequence (S))
and then
(Present
(Exception_Handlers (Handled_Statement_Sequence (S)))
or else
Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (S))))
then
return True;
end if;
elsif Nkind (S) = N_Case_Statement then
E := First (Alternatives (S));
while Present (E) loop
if Has_Excluded_Statement (Statements (E)) then
return True;
end if;
Next (E);
end loop;
elsif Nkind (S) = N_If_Statement then
if Has_Excluded_Statement (Then_Statements (S)) then
return True;
end if;
if Present (Elsif_Parts (S)) then
E := First (Elsif_Parts (S));
while Present (E) loop
if Has_Excluded_Statement (Then_Statements (E)) then
return True;
end if;
Next (E);
end loop;
end if;
if Present (Else_Statements (S))
and then Has_Excluded_Statement (Else_Statements (S))
then
return True;
end if;
elsif Nkind (S) = N_Loop_Statement
and then Has_Excluded_Statement (Statements (S))
then
return True;
elsif Nkind (S) = N_Extended_Return_Statement then
if Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (S)))
or else Present
(Exception_Handlers (Handled_Statement_Sequence (S)))
then
return True;
end if;
end if;
Next (S);
end loop;
return False;
end Has_Excluded_Statement;
-------------------------------
-- Has_Pending_Instantiation --
-------------------------------
function Has_Pending_Instantiation return Boolean is
S : Entity_Id;
begin
S := Current_Scope;
while Present (S) loop
if Is_Compilation_Unit (S)
or else Is_Child_Unit (S)
then
return False;
elsif Ekind (S) = E_Package
and then Has_Forward_Instantiation (S)
then
return True;
end if;
S := Scope (S);
end loop;
return False;
end Has_Pending_Instantiation;
------------------------
-- Has_Single_Return --
------------------------
function Has_Single_Return return Boolean is
Return_Statement : Node_Id := Empty;
function Check_Return (N : Node_Id) return Traverse_Result;
------------------
-- Check_Return --
------------------
function Check_Return (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Simple_Return_Statement then
if Present (Expression (N))
and then Is_Entity_Name (Expression (N))
then
if No (Return_Statement) then
Return_Statement := N;
return OK;
elsif Chars (Expression (N)) =
Chars (Expression (Return_Statement))
then
return OK;
else
return Abandon;
end if;
-- A return statement within an extended return is a noop
-- after inlining.
elsif No (Expression (N))
and then Nkind (Parent (Parent (N))) =
N_Extended_Return_Statement
then
return OK;
else
-- Expression has wrong form
return Abandon;
end if;
-- We can only inline a build-in-place function if
-- it has a single extended return.
elsif Nkind (N) = N_Extended_Return_Statement then
if No (Return_Statement) then
Return_Statement := N;
return OK;
else
return Abandon;
end if;
else
return OK;
end if;
end Check_Return;
function Check_All_Returns is new Traverse_Func (Check_Return);
-- Start of processing for Has_Single_Return
begin
if Check_All_Returns (N) /= OK then
return False;
elsif Nkind (Return_Statement) = N_Extended_Return_Statement then
return True;
else
return Present (Declarations (N))
and then Present (First (Declarations (N)))
and then Chars (Expression (Return_Statement)) =
Chars (Defining_Identifier (First (Declarations (N))));
end if;
end Has_Single_Return;
--------------------
-- Remove_Pragmas --
--------------------
procedure Remove_Pragmas is
Decl : Node_Id;
Nxt : Node_Id;
begin
Decl := First (Declarations (Body_To_Analyze));
while Present (Decl) loop
Nxt := Next (Decl);
if Nkind (Decl) = N_Pragma
and then Nam_In (Pragma_Name (Decl), Name_Unreferenced,
Name_Unmodified)
then
Remove (Decl);
end if;
Decl := Nxt;
end loop;
end Remove_Pragmas;
--------------------------
-- Uses_Secondary_Stack --
--------------------------
function Uses_Secondary_Stack (Bod : Node_Id) return Boolean is
function Check_Call (N : Node_Id) return Traverse_Result;
-- Look for function calls that return an unconstrained type
----------------
-- Check_Call --
----------------
function Check_Call (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Function_Call
and then Is_Entity_Name (Name (N))
and then Is_Composite_Type (Etype (Entity (Name (N))))
and then not Is_Constrained (Etype (Entity (Name (N))))
then
Cannot_Inline
("cannot inline & (call returns unconstrained type)?",
N, Subp);
return Abandon;
else
return OK;
end if;
end Check_Call;
function Check_Calls is new Traverse_Func (Check_Call);
begin
return Check_Calls (Bod) = Abandon;
end Uses_Secondary_Stack;
-- Start of processing for Build_Body_To_Inline
begin
-- Return immediately if done already
if Nkind (Decl) = N_Subprogram_Declaration
and then Present (Body_To_Inline (Decl))
then
return;
-- Functions that return unconstrained composite types require
-- secondary stack handling, and cannot currently be inlined, unless
-- all return statements return a local variable that is the first
-- local declaration in the body.
elsif Ekind (Subp) = E_Function
and then not Is_Scalar_Type (Etype (Subp))
and then not Is_Access_Type (Etype (Subp))
and then not Is_Constrained (Etype (Subp))
then
if not Has_Single_Return then
Cannot_Inline
("cannot inline & (unconstrained return type)?", N, Subp);
return;
end if;
-- Ditto for functions that return controlled types, where controlled
-- actions interfere in complex ways with inlining.
elsif Ekind (Subp) = E_Function
and then Needs_Finalization (Etype (Subp))
then
Cannot_Inline
("cannot inline & (controlled return type)?", N, Subp);
return;
end if;
if Present (Declarations (N))
and then Has_Excluded_Declaration (Declarations (N))
then
return;
end if;
if Present (Handled_Statement_Sequence (N)) then
if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then
Cannot_Inline
("cannot inline& (exception handler)?",
First (Exception_Handlers (Handled_Statement_Sequence (N))),
Subp);
return;
elsif
Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (N)))
then
return;
end if;
end if;
-- We do not inline a subprogram that is too large, unless it is
-- marked Inline_Always. This pragma does not suppress the other
-- checks on inlining (forbidden declarations, handlers, etc).
if Stat_Count > Max_Size
and then not Has_Pragma_Inline_Always (Subp)
then
Cannot_Inline ("cannot inline& (body too large)?", N, Subp);
return;
end if;
if Has_Pending_Instantiation then
Cannot_Inline
("cannot inline& (forward instance within enclosing body)?",
N, Subp);
return;
end if;
-- Within an instance, the body to inline must be treated as a nested
-- generic, so that the proper global references are preserved.
-- Note that we do not do this at the library level, because it is not
-- needed, and furthermore this causes trouble if front end inlining
-- is activated (-gnatN).
if In_Instance and then Scope (Current_Scope) /= Standard_Standard then
Save_Env (Scope (Current_Scope), Scope (Current_Scope));
Original_Body := Copy_Generic_Node (N, Empty, True);
else
Original_Body := Copy_Separate_Tree (N);
end if;
-- We need to capture references to the formals in order to substitute
-- the actuals at the point of inlining, i.e. instantiation. To treat
-- the formals as globals to the body to inline, we nest it within
-- a dummy parameterless subprogram, declared within the real one.
-- To avoid generating an internal name (which is never public, and
-- which affects serial numbers of other generated names), we use
-- an internal symbol that cannot conflict with user declarations.
Set_Parameter_Specifications (Specification (Original_Body), No_List);
Set_Defining_Unit_Name
(Specification (Original_Body),
Make_Defining_Identifier (Sloc (N), Name_uParent));
Set_Corresponding_Spec (Original_Body, Empty);
Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
-- Set return type of function, which is also global and does not need
-- to be resolved.
if Ekind (Subp) = E_Function then
Set_Result_Definition (Specification (Body_To_Analyze),
New_Occurrence_Of (Etype (Subp), Sloc (N)));
end if;
if No (Declarations (N)) then
Set_Declarations (N, New_List (Body_To_Analyze));
else
Append (Body_To_Analyze, Declarations (N));
end if;
Expander_Mode_Save_And_Set (False);
Remove_Pragmas;
Analyze (Body_To_Analyze);
Push_Scope (Defining_Entity (Body_To_Analyze));
Save_Global_References (Original_Body);
End_Scope;
Remove (Body_To_Analyze);
Expander_Mode_Restore;
-- Restore environment if previously saved
if In_Instance and then Scope (Current_Scope) /= Standard_Standard then
Restore_Env;
end if;
-- If secondary stk used there is no point in inlining. We have
-- already issued the warning in this case, so nothing to do.
if Uses_Secondary_Stack (Body_To_Analyze) then
return;
end if;
Set_Body_To_Inline (Decl, Original_Body);
Set_Ekind (Defining_Entity (Original_Body), Ekind (Subp));
Set_Is_Inlined (Subp);
end Build_Body_To_Inline;
-------------------
-- Cannot_Inline --
-------------------
procedure Cannot_Inline
(Msg : String;
N : Node_Id;
Subp : Entity_Id;
Is_Serious : Boolean := False)
is
begin
pragma Assert (Msg (Msg'Last) = '?');
-- Old semantics
if not Debug_Flag_Dot_K then
-- Do not emit warning if this is a predefined unit which is not
-- the main unit. With validity checks enabled, some predefined
-- subprograms may contain nested subprograms and become ineligible
-- for inlining.
if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp)))
and then not In_Extended_Main_Source_Unit (Subp)
then
null;
elsif Has_Pragma_Inline_Always (Subp) then
-- Remove last character (question mark) to make this into an
-- error, because the Inline_Always pragma cannot be obeyed.
Error_Msg_NE (Msg (Msg'First .. Msg'Last - 1), N, Subp);
elsif Ineffective_Inline_Warnings then
Error_Msg_NE (Msg & "p?", N, Subp);
end if;
return;
-- New semantics
elsif Is_Serious then
-- Remove last character (question mark) to make this into an error.
Error_Msg_NE (Msg (Msg'First .. Msg'Last - 1), N, Subp);
elsif Optimization_Level = 0 then
-- Do not emit warning if this is a predefined unit which is not
-- the main unit. This behavior is currently provided for backward
-- compatibility but it will be removed when we enforce the
-- strictness of the new rules.
if Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (Subp)))
and then not In_Extended_Main_Source_Unit (Subp)
then
null;
elsif Has_Pragma_Inline_Always (Subp) then
-- Emit a warning if this is a call to a runtime subprogram
-- which is located inside a generic. Previously this call
-- was silently skipped!
if Is_Generic_Instance (Subp) then
declare
Gen_P : constant Entity_Id := Generic_Parent (Parent (Subp));
begin
if Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Gen_P)))
then
Set_Is_Inlined (Subp, False);
Error_Msg_NE (Msg & "p?", N, Subp);
return;
end if;
end;
end if;
-- Remove last character (question mark) to make this into an
-- error, because the Inline_Always pragma cannot be obeyed.
Error_Msg_NE (Msg (Msg'First .. Msg'Last - 1), N, Subp);
else pragma Assert (Front_End_Inlining);
Set_Is_Inlined (Subp, False);
-- When inlining cannot take place we must issue an error.
-- For backward compatibility we still report a warning.
if Ineffective_Inline_Warnings then
Error_Msg_NE (Msg & "p?", N, Subp);
end if;
end if;
-- Compiling with optimizations enabled it is too early to report
-- problems since the backend may still perform inlining. In order
-- to report unhandled inlinings the program must be compiled with
-- -Winline and the error is reported by the backend.
else
null;
end if;
end Cannot_Inline;
------------------------------------
-- Check_And_Build_Body_To_Inline --
------------------------------------
procedure Check_And_Build_Body_To_Inline
(N : Node_Id;
Spec_Id : Entity_Id;
Body_Id : Entity_Id)
is
procedure Build_Body_To_Inline (N : Node_Id; Spec_Id : Entity_Id);
-- Use generic machinery to build an unexpanded body for the subprogram.
-- This body is subsequently used for inline expansions at call sites.
function Can_Split_Unconstrained_Function (N : Node_Id) return Boolean;
-- Return true if we generate code for the function body N, the function
-- body N has no local declarations and its unique statement is a single
-- extended return statement with a handled statements sequence.
function Check_Body_To_Inline
(N : Node_Id;
Subp : Entity_Id) return Boolean;
-- N is the N_Subprogram_Body of Subp. Return true if Subp can be
-- inlined by the frontend. These are the rules:
-- * At -O0 use fe inlining when inline_always is specified except if
-- the function returns a controlled type.
-- * At other optimization levels use the fe inlining for both inline
-- and inline_always in the following cases:
-- - function returning a known at compile time constant
-- - function returning a call to an intrinsic function
-- - function returning an unconstrained type (see Can_Split
-- Unconstrained_Function).
-- - function returning a call to a frontend-inlined function
-- Use the back-end mechanism otherwise
--
-- In addition, in the following cases the function cannot be inlined by
-- the frontend:
-- - functions that uses the secondary stack
-- - functions that have declarations of:
-- - Concurrent types
-- - Packages
-- - Instantiations
-- - Subprograms
-- - functions that have some of the following statements:
-- - abort
-- - asynchronous-select
-- - conditional-entry-call
-- - delay-relative
-- - delay-until
-- - selective-accept
-- - timed-entry-call
-- - functions that have exception handlers
-- - functions that have some enclosing body containing instantiations
-- that appear before the corresponding generic body.
procedure Generate_Body_To_Inline
(N : Node_Id;
Body_To_Inline : out Node_Id);
-- Generate a parameterless duplicate of subprogram body N. Occurrences
-- of pragmas referencing the formals are removed since they have no
-- meaning when the body is inlined and the formals are rewritten (the
-- analysis of the non-inlined body will handle these pragmas properly).
-- A new internal name is associated with Body_To_Inline.
procedure Split_Unconstrained_Function
(N : Node_Id;
Spec_Id : Entity_Id);
-- N is an inlined function body that returns an unconstrained type and
-- has a single extended return statement. Split N in two subprograms:
-- a procedure P' and a function F'. The formals of P' duplicate the
-- formals of N plus an extra formal which is used return a value;
-- its body is composed by the declarations and list of statements
-- of the extended return statement of N.
--------------------------
-- Build_Body_To_Inline --
--------------------------
procedure Build_Body_To_Inline (N : Node_Id; Spec_Id : Entity_Id) is
Decl : constant Node_Id := Unit_Declaration_Node (Spec_Id);
Original_Body : Node_Id;
Body_To_Analyze : Node_Id;
begin
pragma Assert (Current_Scope = Spec_Id);
-- Within an instance, the body to inline must be treated as a nested
-- generic, so that the proper global references are preserved. We
-- do not do this at the library level, because it is not needed, and
-- furthermore this causes trouble if front end inlining is activated
-- (-gnatN).
if In_Instance
and then Scope (Current_Scope) /= Standard_Standard
then
Save_Env (Scope (Current_Scope), Scope (Current_Scope));
end if;
-- We need to capture references to the formals in order
-- to substitute the actuals at the point of inlining, i.e.
-- instantiation. To treat the formals as globals to the body to
-- inline, we nest it within a dummy parameterless subprogram,
-- declared within the real one.
Generate_Body_To_Inline (N, Original_Body);
Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
-- Set return type of function, which is also global and does not
-- need to be resolved.
if Ekind (Spec_Id) = E_Function then
Set_Result_Definition (Specification (Body_To_Analyze),
New_Occurrence_Of (Etype (Spec_Id), Sloc (N)));
end if;
if No (Declarations (N)) then
Set_Declarations (N, New_List (Body_To_Analyze));
else
Append_To (Declarations (N), Body_To_Analyze);
end if;
Preanalyze (Body_To_Analyze);
Push_Scope (Defining_Entity (Body_To_Analyze));
Save_Global_References (Original_Body);
End_Scope;
Remove (Body_To_Analyze);
-- Restore environment if previously saved
if In_Instance
and then Scope (Current_Scope) /= Standard_Standard
then
Restore_Env;
end if;
pragma Assert (No (Body_To_Inline (Decl)));
Set_Body_To_Inline (Decl, Original_Body);
Set_Ekind (Defining_Entity (Original_Body), Ekind (Spec_Id));
end Build_Body_To_Inline;
--------------------------
-- Check_Body_To_Inline --
--------------------------
function Check_Body_To_Inline
(N : Node_Id;
Subp : Entity_Id) return Boolean
is
Max_Size : constant := 10;
Stat_Count : Integer := 0;
function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
-- Check for declarations that make inlining not worthwhile
function Has_Excluded_Statement (Stats : List_Id) return Boolean;
-- Check for statements that make inlining not worthwhile: any
-- tasking statement, nested at any level. Keep track of total
-- number of elementary statements, as a measure of acceptable size.
function Has_Pending_Instantiation return Boolean;
-- Return True if some enclosing body contains instantiations that
-- appear before the corresponding generic body.
function Returns_Compile_Time_Constant (N : Node_Id) return Boolean;
-- Return True if all the return statements of the function body N
-- are simple return statements and return a compile time constant
function Returns_Intrinsic_Function_Call (N : Node_Id) return Boolean;
-- Return True if all the return statements of the function body N
-- are simple return statements and return an intrinsic function call
function Uses_Secondary_Stack (N : Node_Id) return Boolean;
-- If the body of the subprogram includes a call that returns an
-- unconstrained type, the secondary stack is involved, and it
-- is not worth inlining.
------------------------------
-- Has_Excluded_Declaration --
------------------------------
function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
D : Node_Id;
function Is_Unchecked_Conversion (D : Node_Id) return Boolean;
-- Nested subprograms make a given body ineligible for inlining,
-- but we make an exception for instantiations of unchecked
-- conversion. The body has not been analyzed yet, so check the
-- name, and verify that the visible entity with that name is the
-- predefined unit.
-----------------------------
-- Is_Unchecked_Conversion --
-----------------------------
function Is_Unchecked_Conversion (D : Node_Id) return Boolean is
Id : constant Node_Id := Name (D);
Conv : Entity_Id;
begin
if Nkind (Id) = N_Identifier
and then Chars (Id) = Name_Unchecked_Conversion
then
Conv := Current_Entity (Id);
elsif Nkind_In (Id, N_Selected_Component, N_Expanded_Name)
and then
Chars (Selector_Name (Id)) = Name_Unchecked_Conversion
then
Conv := Current_Entity (Selector_Name (Id));
else
return False;
end if;
return Present (Conv)
and then Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Conv)))
and then Is_Intrinsic_Subprogram (Conv);
end Is_Unchecked_Conversion;
-- Start of processing for Has_Excluded_Declaration
begin
D := First (Decls);
while Present (D) loop
if (Nkind (D) = N_Function_Instantiation
and then not Is_Unchecked_Conversion (D))
or else Nkind_In (D, N_Protected_Type_Declaration,
N_Package_Declaration,
N_Package_Instantiation,
N_Subprogram_Body,
N_Procedure_Instantiation,
N_Task_Type_Declaration)
then
Cannot_Inline
("cannot inline & (non-allowed declaration)?", D, Subp);
return True;
end if;
Next (D);
end loop;
return False;
end Has_Excluded_Declaration;
----------------------------
-- Has_Excluded_Statement --
----------------------------
function Has_Excluded_Statement (Stats : List_Id) return Boolean is
S : Node_Id;
E : Node_Id;
begin
S := First (Stats);
while Present (S) loop
Stat_Count := Stat_Count + 1;
if Nkind_In (S, N_Abort_Statement,
N_Asynchronous_Select,
N_Conditional_Entry_Call,
N_Delay_Relative_Statement,
N_Delay_Until_Statement,
N_Selective_Accept,
N_Timed_Entry_Call)
then
Cannot_Inline
("cannot inline & (non-allowed statement)?", S, Subp);
return True;
elsif Nkind (S) = N_Block_Statement then
if Present (Declarations (S))
and then Has_Excluded_Declaration (Declarations (S))
then
return True;
elsif Present (Handled_Statement_Sequence (S)) then
if Present
(Exception_Handlers (Handled_Statement_Sequence (S)))
then
Cannot_Inline
("cannot inline& (exception handler)?",
First (Exception_Handlers
(Handled_Statement_Sequence (S))),
Subp);
return True;
elsif Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (S)))
then
return True;
end if;
end if;
elsif Nkind (S) = N_Case_Statement then
E := First (Alternatives (S));
while Present (E) loop
if Has_Excluded_Statement (Statements (E)) then
return True;
end if;
Next (E);
end loop;
elsif Nkind (S) = N_If_Statement then
if Has_Excluded_Statement (Then_Statements (S)) then
return True;
end if;
if Present (Elsif_Parts (S)) then
E := First (Elsif_Parts (S));
while Present (E) loop
if Has_Excluded_Statement (Then_Statements (E)) then
return True;
end if;
Next (E);
end loop;
end if;
if Present (Else_Statements (S))
and then Has_Excluded_Statement (Else_Statements (S))
then
return True;
end if;
elsif Nkind (S) = N_Loop_Statement
and then Has_Excluded_Statement (Statements (S))
then
return True;
elsif Nkind (S) = N_Extended_Return_Statement then
if Present (Handled_Statement_Sequence (S))
and then
Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (S)))
then
return True;
elsif Present (Handled_Statement_Sequence (S))
and then
Present (Exception_Handlers
(Handled_Statement_Sequence (S)))
then
Cannot_Inline
("cannot inline& (exception handler)?",
First (Exception_Handlers
(Handled_Statement_Sequence (S))),
Subp);
return True;
end if;
end if;
Next (S);
end loop;
return False;
end Has_Excluded_Statement;
-------------------------------
-- Has_Pending_Instantiation --
-------------------------------
function Has_Pending_Instantiation return Boolean is
S : Entity_Id;
begin
S := Current_Scope;
while Present (S) loop
if Is_Compilation_Unit (S)
or else Is_Child_Unit (S)
then
return False;
elsif Ekind (S) = E_Package
and then Has_Forward_Instantiation (S)
then
return True;
end if;
S := Scope (S);
end loop;
return False;
end Has_Pending_Instantiation;
------------------------------------
-- Returns_Compile_Time_Constant --
------------------------------------
function Returns_Compile_Time_Constant (N : Node_Id) return Boolean is
function Check_Return (N : Node_Id) return Traverse_Result;
------------------
-- Check_Return --
------------------
function Check_Return (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Extended_Return_Statement then
return Abandon;
elsif Nkind (N) = N_Simple_Return_Statement then
if Present (Expression (N)) then
declare
Orig_Expr : constant Node_Id :=
Original_Node (Expression (N));
begin
if Nkind_In (Orig_Expr, N_Integer_Literal,
N_Real_Literal,
N_Character_Literal)
then
return OK;
elsif Is_Entity_Name (Orig_Expr)
and then Ekind (Entity (Orig_Expr)) = E_Constant
and then Is_Static_Expression (Orig_Expr)
then
return OK;
else
return Abandon;
end if;
end;
-- Expression has wrong form
else
return Abandon;
end if;
-- Continue analyzing statements
else
return OK;
end if;
end Check_Return;
function Check_All_Returns is new Traverse_Func (Check_Return);
-- Start of processing for Returns_Compile_Time_Constant
begin
return Check_All_Returns (N) = OK;
end Returns_Compile_Time_Constant;
--------------------------------------
-- Returns_Intrinsic_Function_Call --
--------------------------------------
function Returns_Intrinsic_Function_Call
(N : Node_Id) return Boolean
is
function Check_Return (N : Node_Id) return Traverse_Result;
------------------
-- Check_Return --
------------------
function Check_Return (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Extended_Return_Statement then
return Abandon;
elsif Nkind (N) = N_Simple_Return_Statement then
if Present (Expression (N)) then
declare
Orig_Expr : constant Node_Id :=
Original_Node (Expression (N));
begin
if Nkind (Orig_Expr) in N_Op
and then Is_Intrinsic_Subprogram (Entity (Orig_Expr))
then
return OK;
elsif Nkind (Orig_Expr) in N_Has_Entity
and then Present (Entity (Orig_Expr))
and then Ekind (Entity (Orig_Expr)) = E_Function
and then Is_Inlined (Entity (Orig_Expr))
then
return OK;
elsif Nkind (Orig_Expr) in N_Has_Entity
and then Present (Entity (Orig_Expr))
and then Is_Intrinsic_Subprogram (Entity (Orig_Expr))
then
return OK;
else
return Abandon;
end if;
end;
-- Expression has wrong form
else
return Abandon;
end if;
-- Continue analyzing statements
else
return OK;
end if;
end Check_Return;
function Check_All_Returns is new Traverse_Func (Check_Return);
-- Start of processing for Returns_Intrinsic_Function_Call
begin
return Check_All_Returns (N) = OK;
end Returns_Intrinsic_Function_Call;
--------------------------
-- Uses_Secondary_Stack --
--------------------------
function Uses_Secondary_Stack (N : Node_Id) return Boolean is
function Check_Call (N : Node_Id) return Traverse_Result;
-- Look for function calls that return an unconstrained type
----------------
-- Check_Call --
----------------
function Check_Call (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Function_Call
and then Is_Entity_Name (Name (N))
and then Is_Composite_Type (Etype (Entity (Name (N))))
and then not Is_Constrained (Etype (Entity (Name (N))))
then
Cannot_Inline
("cannot inline & (call returns unconstrained type)?",
N, Subp);
return Abandon;
else
return OK;
end if;
end Check_Call;
function Check_Calls is new Traverse_Func (Check_Call);
-- Start of processing for Uses_Secondary_Stack
begin
return Check_Calls (N) = Abandon;
end Uses_Secondary_Stack;
-- Local variables
Decl : constant Node_Id := Unit_Declaration_Node (Spec_Id);
May_Inline : constant Boolean :=
Has_Pragma_Inline_Always (Spec_Id)
or else (Has_Pragma_Inline (Spec_Id)
and then ((Optimization_Level > 0
and then Ekind (Spec_Id)
= E_Function)
or else Front_End_Inlining));
Body_To_Analyze : Node_Id;
-- Start of processing for Check_Body_To_Inline
begin
-- No action needed in stubs since the attribute Body_To_Inline
-- is not available
if Nkind (Decl) = N_Subprogram_Body_Stub then
return False;
-- Cannot build the body to inline if the attribute is already set.
-- This attribute may have been set if this is a subprogram renaming
-- declarations (see Freeze.Build_Renamed_Body).
elsif Present (Body_To_Inline (Decl)) then
return False;
-- No action needed if the subprogram does not fulfill the minimum
-- conditions to be inlined by the frontend
elsif not May_Inline then
return False;
end if;
-- Check excluded declarations
if Present (Declarations (N))
and then Has_Excluded_Declaration (Declarations (N))
then
return False;
end if;
-- Check excluded statements
if Present (Handled_Statement_Sequence (N)) then
if Present
(Exception_Handlers (Handled_Statement_Sequence (N)))
then
Cannot_Inline
("cannot inline& (exception handler)?",
First
(Exception_Handlers (Handled_Statement_Sequence (N))),
Subp);
return False;
elsif Has_Excluded_Statement
(Statements (Handled_Statement_Sequence (N)))
then
return False;
end if;
end if;
-- For backward compatibility, compiling under -gnatN we do not
-- inline a subprogram that is too large, unless it is marked
-- Inline_Always. This pragma does not suppress the other checks
-- on inlining (forbidden declarations, handlers, etc).
if Front_End_Inlining
and then not Has_Pragma_Inline_Always (Subp)
and then Stat_Count > Max_Size
then
Cannot_Inline ("cannot inline& (body too large)?", N, Subp);
return False;
end if;
-- If some enclosing body contains instantiations that appear before
-- the corresponding generic body, the enclosing body has a freeze
-- node so that it can be elaborated after the generic itself. This
-- might conflict with subsequent inlinings, so that it is unsafe to
-- try to inline in such a case.
if Has_Pending_Instantiation then
Cannot_Inline
("cannot inline& (forward instance within enclosing body)?",
N, Subp);
return False;
end if;
-- Generate and preanalyze the body to inline (needed to perform
-- the rest of the checks)
Generate_Body_To_Inline (N, Body_To_Analyze);
if Ekind (Subp) = E_Function then
Set_Result_Definition (Specification (Body_To_Analyze),
New_Occurrence_Of (Etype (Subp), Sloc (N)));
end if;
-- Nest the body to analyze within the real one
if No (Declarations (N)) then
Set_Declarations (N, New_List (Body_To_Analyze));
else
Append_To (Declarations (N), Body_To_Analyze);
end if;
Preanalyze (Body_To_Analyze);
Remove (Body_To_Analyze);
-- Keep separate checks needed when compiling without optimizations
if Optimization_Level = 0
-- AAMP and VM targets have no support for inlining in the backend
-- and hence we use frontend inlining at all optimization levels.
or else AAMP_On_Target
or else VM_Target /= No_VM
then
-- Cannot inline functions whose body has a call that returns an
-- unconstrained type since the secondary stack is involved, and
-- it is not worth inlining.
if Uses_Secondary_Stack (Body_To_Analyze) then
return False;
-- Cannot inline functions that return controlled types since
-- controlled actions interfere in complex ways with inlining.
elsif Ekind (Subp) = E_Function
and then Needs_Finalization (Etype (Subp))
then
Cannot_Inline
("cannot inline & (controlled return type)?", N, Subp);
return False;
elsif Returns_Unconstrained_Type (Subp) then
Cannot_Inline
("cannot inline & (unconstrained return type)?", N, Subp);
return False;
end if;
-- Compiling with optimizations enabled
else
-- Procedures are never frontend inlined in this case!
if Ekind (Subp) /= E_Function then
return False;
-- Functions returning unconstrained types are tested
-- separately (see Can_Split_Unconstrained_Function).
elsif Returns_Unconstrained_Type (Subp) then
null;
-- Check supported cases
elsif not Returns_Compile_Time_Constant (Body_To_Analyze)
and then Convention (Subp) /= Convention_Intrinsic
and then not Returns_Intrinsic_Function_Call (Body_To_Analyze)
then
return False;
end if;
end if;
return True;
end Check_Body_To_Inline;
--------------------------------------
-- Can_Split_Unconstrained_Function --
--------------------------------------
function Can_Split_Unconstrained_Function (N : Node_Id) return Boolean
is
Ret_Node : constant Node_Id :=
First (Statements (Handled_Statement_Sequence (N)));
D : Node_Id;
begin
-- No user defined declarations allowed in the function except inside
-- the unique return statement; implicit labels are the only allowed
-- declarations.
if not Is_Empty_List (Declarations (N)) then
D := First (Declarations (N));
while Present (D) loop
if Nkind (D) /= N_Implicit_Label_Declaration then
return False;
end if;
Next (D);
end loop;
end if;
-- We only split the inlined function when we are generating the code
-- of its body; otherwise we leave duplicated split subprograms in
-- the tree which (if referenced) generate wrong references at link
-- time.
return In_Extended_Main_Code_Unit (N)
and then Present (Ret_Node)
and then Nkind (Ret_Node) = N_Extended_Return_Statement
and then No (Next (Ret_Node))
and then Present (Handled_Statement_Sequence (Ret_Node));
end Can_Split_Unconstrained_Function;
-----------------------------
-- Generate_Body_To_Inline --
-----------------------------
procedure Generate_Body_To_Inline
(N : Node_Id;
Body_To_Inline : out Node_Id)
is
procedure Remove_Pragmas (N : Node_Id);
-- Remove occurrences of pragmas that may reference the formals of
-- N. The analysis of the non-inlined body will handle these pragmas
-- properly.
--------------------
-- Remove_Pragmas --
--------------------
procedure Remove_Pragmas (N : Node_Id) is
Decl : Node_Id;
Nxt : Node_Id;
begin
Decl := First (Declarations (N));
while Present (Decl) loop
Nxt := Next (Decl);
if Nkind (Decl) = N_Pragma
and then Nam_In (Pragma_Name (Decl), Name_Unreferenced,
Name_Unmodified)
then
Remove (Decl);
end if;
Decl := Nxt;
end loop;
end Remove_Pragmas;
-- Start of processing for Generate_Body_To_Inline
begin
-- Within an instance, the body to inline must be treated as a nested
-- generic, so that the proper global references are preserved.
-- Note that we do not do this at the library level, because it
-- is not needed, and furthermore this causes trouble if front
-- end inlining is activated (-gnatN).
if In_Instance
and then Scope (Current_Scope) /= Standard_Standard
then
Body_To_Inline := Copy_Generic_Node (N, Empty, True);
else
Body_To_Inline := Copy_Separate_Tree (N);
end if;
-- A pragma Unreferenced or pragma Unmodified that mentions a formal
-- parameter has no meaning when the body is inlined and the formals
-- are rewritten. Remove it from body to inline. The analysis of the
-- non-inlined body will handle the pragma properly.
Remove_Pragmas (Body_To_Inline);
-- We need to capture references to the formals in order
-- to substitute the actuals at the point of inlining, i.e.
-- instantiation. To treat the formals as globals to the body to
-- inline, we nest it within a dummy parameterless subprogram,
-- declared within the real one.
Set_Parameter_Specifications
(Specification (Body_To_Inline), No_List);
-- A new internal name is associated with Body_To_Inline to avoid
-- conflicts when the non-inlined body N is analyzed.
Set_Defining_Unit_Name (Specification (Body_To_Inline),
Make_Defining_Identifier (Sloc (N), New_Internal_Name ('P')));
Set_Corresponding_Spec (Body_To_Inline, Empty);
end Generate_Body_To_Inline;
----------------------------------
-- Split_Unconstrained_Function --
----------------------------------
procedure Split_Unconstrained_Function
(N : Node_Id;
Spec_Id : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Ret_Node : constant Node_Id :=
First (Statements (Handled_Statement_Sequence (N)));
Ret_Obj : constant Node_Id :=
First (Return_Object_Declarations (Ret_Node));
procedure Build_Procedure
(Proc_Id : out Entity_Id;
Decl_List : out List_Id);
-- Build a procedure containing the statements found in the extended
-- return statement of the unconstrained function body N.
procedure Build_Procedure
(Proc_Id : out Entity_Id;
Decl_List : out List_Id)
is
Formal : Entity_Id;
Formal_List : constant List_Id := New_List;
Proc_Spec : Node_Id;
Proc_Body : Node_Id;
Subp_Name : constant Name_Id := New_Internal_Name ('F');
Body_Decl_List : List_Id := No_List;
Param_Type : Node_Id;
begin
if Nkind (Object_Definition (Ret_Obj)) = N_Identifier then
Param_Type := New_Copy (Object_Definition (Ret_Obj));
else
Param_Type :=
New_Copy (Subtype_Mark (Object_Definition (Ret_Obj)));
end if;
Append_To (Formal_List,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc,
Chars => Chars (Defining_Identifier (Ret_Obj))),
In_Present => False,
Out_Present => True,
Null_Exclusion_Present => False,
Parameter_Type => Param_Type));
Formal := First_Formal (Spec_Id);
while Present (Formal) loop
Append_To (Formal_List,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Sloc (Formal),
Chars => Chars (Formal)),
In_Present => In_Present (Parent (Formal)),
Out_Present => Out_Present (Parent (Formal)),
Null_Exclusion_Present =>
Null_Exclusion_Present (Parent (Formal)),
Parameter_Type =>
New_Reference_To (Etype (Formal), Loc),
Expression =>
Copy_Separate_Tree (Expression (Parent (Formal)))));
Next_Formal (Formal);
end loop;
Proc_Id :=
Make_Defining_Identifier (Loc, Chars => Subp_Name);
Proc_Spec :=
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Proc_Id,
Parameter_Specifications => Formal_List);
Decl_List := New_List;
Append_To (Decl_List,
Make_Subprogram_Declaration (Loc, Proc_Spec));
-- Can_Convert_Unconstrained_Function checked that the function
-- has no local declarations except implicit label declarations.
-- Copy these declarations to the built procedure.
if Present (Declarations (N)) then
Body_Decl_List := New_List;
declare
D : Node_Id;
New_D : Node_Id;
begin
D := First (Declarations (N));
while Present (D) loop
pragma Assert (Nkind (D) = N_Implicit_Label_Declaration);
New_D :=
Make_Implicit_Label_Declaration (Loc,
Make_Defining_Identifier (Loc,
Chars => Chars (Defining_Identifier (D))),
Label_Construct => Empty);
Append_To (Body_Decl_List, New_D);
Next (D);
end loop;
end;
end if;
pragma Assert (Present (Handled_Statement_Sequence (Ret_Node)));
Proc_Body :=
Make_Subprogram_Body (Loc,
Specification => Copy_Separate_Tree (Proc_Spec),
Declarations => Body_Decl_List,
Handled_Statement_Sequence =>
Copy_Separate_Tree (Handled_Statement_Sequence (Ret_Node)));
Set_Defining_Unit_Name (Specification (Proc_Body),
Make_Defining_Identifier (Loc, Subp_Name));
Append_To (Decl_List, Proc_Body);
end Build_Procedure;
-- Local variables
New_Obj : constant Node_Id := Copy_Separate_Tree (Ret_Obj);
Blk_Stmt : Node_Id;
Proc_Id : Entity_Id;
Proc_Call : Node_Id;
-- Start of processing for Split_Unconstrained_Function
begin
-- Build the associated procedure, analyze it and insert it before
-- the function body N
declare
Scope : constant Entity_Id := Current_Scope;
Decl_List : List_Id;
begin
Pop_Scope;
Build_Procedure (Proc_Id, Decl_List);
Insert_Actions (N, Decl_List);
Push_Scope (Scope);
end;
-- Build the call to the generated procedure
declare
Actual_List : constant List_Id := New_List;
Formal : Entity_Id;
begin
Append_To (Actual_List,
New_Reference_To (Defining_Identifier (New_Obj), Loc));
Formal := First_Formal (Spec_Id);
while Present (Formal) loop
Append_To (Actual_List, New_Reference_To (Formal, Loc));
-- Avoid spurious warning on unreferenced formals
Set_Referenced (Formal);
Next_Formal (Formal);
end loop;
Proc_Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Proc_Id, Loc),
Parameter_Associations => Actual_List);
end;
-- Generate
-- declare
-- New_Obj : ...
-- begin
-- main_1__F1b (New_Obj, ...);
-- return Obj;
-- end B10b;
Blk_Stmt :=
Make_Block_Statement (Loc,
Declarations => New_List (New_Obj),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Proc_Call,
Make_Simple_Return_Statement (Loc,
Expression =>
New_Reference_To
(Defining_Identifier (New_Obj), Loc)))));
Rewrite (Ret_Node, Blk_Stmt);
end Split_Unconstrained_Function;
-- Start of processing for Check_And_Build_Body_To_Inline
begin
-- Do not inline any subprogram that contains nested subprograms, since
-- the backend inlining circuit seems to generate uninitialized
-- references in this case. We know this happens in the case of front
-- end ZCX support, but it also appears it can happen in other cases as
-- well. The backend often rejects attempts to inline in the case of
-- nested procedures anyway, so little if anything is lost by this.
-- Note that this is test is for the benefit of the back-end. There is
-- a separate test for front-end inlining that also rejects nested
-- subprograms.
-- Do not do this test if errors have been detected, because in some
-- error cases, this code blows up, and we don't need it anyway if
-- there have been errors, since we won't get to the linker anyway.
if Comes_From_Source (Body_Id)
and then (Has_Pragma_Inline_Always (Spec_Id)
or else Optimization_Level > 0)
and then Serious_Errors_Detected = 0
then
declare
P_Ent : Node_Id;
begin
P_Ent := Body_Id;
loop
P_Ent := Scope (P_Ent);
exit when No (P_Ent) or else P_Ent = Standard_Standard;
if Is_Subprogram (P_Ent) then
Set_Is_Inlined (P_Ent, False);
if Comes_From_Source (P_Ent)
and then Has_Pragma_Inline (P_Ent)
then
Cannot_Inline
("cannot inline& (nested subprogram)?", N, P_Ent,
Is_Serious => True);
end if;
end if;
end loop;
end;
end if;
-- Build the body to inline only if really needed!
if Check_Body_To_Inline (N, Spec_Id)
and then Serious_Errors_Detected = 0
then
if Returns_Unconstrained_Type (Spec_Id) then
if Can_Split_Unconstrained_Function (N) then
Split_Unconstrained_Function (N, Spec_Id);
Build_Body_To_Inline (N, Spec_Id);
Set_Is_Inlined (Spec_Id);
end if;
else
Build_Body_To_Inline (N, Spec_Id);
Set_Is_Inlined (Spec_Id);
end if;
end if;
end Check_And_Build_Body_To_Inline;
-----------------------
-- Check_Conformance --
-----------------------
procedure Check_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Ctype : Conformance_Type;
Errmsg : Boolean;
Conforms : out Boolean;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False;
Skip_Controlling_Formals : Boolean := False)
is
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
-- Sets Conforms to False. If Errmsg is False, then that's all it does.
-- If Errmsg is True, then processing continues to post an error message
-- for conformance error on given node. Two messages are output. The
-- first message points to the previous declaration with a general "no
-- conformance" message. The second is the detailed reason, supplied as
-- Msg. The parameter N provide information for a possible & insertion
-- in the message, and also provides the location for posting the
-- message in the absence of a specified Err_Loc location.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
Enode : Node_Id;
begin
Conforms := False;
if Errmsg then
if No (Err_Loc) then
Enode := N;
else
Enode := Err_Loc;
end if;
Error_Msg_Sloc := Sloc (Old_Id);
case Ctype is
when Type_Conformant =>
Error_Msg_N -- CODEFIX
("not type conformant with declaration#!", Enode);
when Mode_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N
("not mode conformant with operation inherited#!",
Enode);
else
Error_Msg_N
("not mode conformant with declaration#!", Enode);
end if;
when Subtype_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N
("not subtype conformant with operation inherited#!",
Enode);
else
Error_Msg_N
("not subtype conformant with declaration#!", Enode);
end if;
when Fully_Conformant =>
if Nkind (Parent (Old_Id)) = N_Full_Type_Declaration then
Error_Msg_N -- CODEFIX
("not fully conformant with operation inherited#!",
Enode);
else
Error_Msg_N -- CODEFIX
("not fully conformant with declaration#!", Enode);
end if;
end case;
Error_Msg_NE (Msg, Enode, N);
end if;
end Conformance_Error;
-- Local Variables
Old_Type : constant Entity_Id := Etype (Old_Id);
New_Type : constant Entity_Id := Etype (New_Id);
Old_Formal : Entity_Id;
New_Formal : Entity_Id;
Access_Types_Match : Boolean;
Old_Formal_Base : Entity_Id;
New_Formal_Base : Entity_Id;
-- Start of processing for Check_Conformance
begin
Conforms := True;
-- We need a special case for operators, since they don't appear
-- explicitly.
if Ctype = Type_Conformant then
if Ekind (New_Id) = E_Operator
and then Operator_Matches_Spec (New_Id, Old_Id)
then
return;
end if;
end if;
-- If both are functions/operators, check return types conform
if Old_Type /= Standard_Void_Type
and then New_Type /= Standard_Void_Type
then
-- If we are checking interface conformance we omit controlling
-- arguments and result, because we are only checking the conformance
-- of the remaining parameters.
if Has_Controlling_Result (Old_Id)
and then Has_Controlling_Result (New_Id)
and then Skip_Controlling_Formals
then
null;
elsif not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
Conformance_Error ("\return type does not match!", New_Id);
return;
end if;
-- Ada 2005 (AI-231): In case of anonymous access types check the
-- null-exclusion and access-to-constant attributes match.
if Ada_Version >= Ada_2005
and then Ekind (Etype (Old_Type)) = E_Anonymous_Access_Type
and then
(Can_Never_Be_Null (Old_Type) /= Can_Never_Be_Null (New_Type)
or else Is_Access_Constant (Etype (Old_Type)) /=
Is_Access_Constant (Etype (New_Type)))
then
Conformance_Error ("\return type does not match!", New_Id);
return;
end if;
-- If either is a function/operator and the other isn't, error
elsif Old_Type /= Standard_Void_Type
or else New_Type /= Standard_Void_Type
then
Conformance_Error ("\functions can only match functions!", New_Id);
return;
end if;
-- In subtype conformant case, conventions must match (RM 6.3.1(16)).
-- If this is a renaming as body, refine error message to indicate that
-- the conflict is with the original declaration. If the entity is not
-- frozen, the conventions don't have to match, the one of the renamed
-- entity is inherited.
if Ctype >= Subtype_Conformant then
if Convention (Old_Id) /= Convention (New_Id) then
if not Is_Frozen (New_Id) then
null;
elsif Present (Err_Loc)
and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Spec (Err_Loc))
then
Error_Msg_Name_1 := Chars (New_Id);
Error_Msg_Name_2 :=
Name_Ada + Convention_Id'Pos (Convention (New_Id));
Conformance_Error ("\prior declaration for% has convention %!");
else
Conformance_Error ("\calling conventions do not match!");
end if;
return;
elsif Is_Formal_Subprogram (Old_Id)
or else Is_Formal_Subprogram (New_Id)
then
Conformance_Error ("\formal subprograms not allowed!");
return;
end if;
end if;
-- Deal with parameters
-- Note: we use the entity information, rather than going directly
-- to the specification in the tree. This is not only simpler, but
-- absolutely necessary for some cases of conformance tests between
-- operators, where the declaration tree simply does not exist!
Old_Formal := First_Formal (Old_Id);
New_Formal := First_Formal (New_Id);
while Present (Old_Formal) and then Present (New_Formal) loop
if Is_Controlling_Formal (Old_Formal)
and then Is_Controlling_Formal (New_Formal)
and then Skip_Controlling_Formals
then
-- The controlling formals will have different types when
-- comparing an interface operation with its match, but both
-- or neither must be access parameters.
if Is_Access_Type (Etype (Old_Formal))
=
Is_Access_Type (Etype (New_Formal))
then
goto Skip_Controlling_Formal;
else
Conformance_Error
("\access parameter does not match!", New_Formal);
end if;
end if;
-- Ada 2012: Mode conformance also requires that formal parameters
-- be both aliased, or neither.
if Ctype >= Mode_Conformant and then Ada_Version >= Ada_2012 then
if Is_Aliased (Old_Formal) /= Is_Aliased (New_Formal) then
Conformance_Error
("\aliased parameter mismatch!", New_Formal);
end if;
end if;
if Ctype = Fully_Conformant then
-- Names must match. Error message is more accurate if we do
-- this before checking that the types of the formals match.
if Chars (Old_Formal) /= Chars (New_Formal) then
Conformance_Error ("\name & does not match!", New_Formal);
-- Set error posted flag on new formal as well to stop
-- junk cascaded messages in some cases.
Set_Error_Posted (New_Formal);
return;
end if;
-- Null exclusion must match
if Null_Exclusion_Present (Parent (Old_Formal))
/=
Null_Exclusion_Present (Parent (New_Formal))
then
-- Only give error if both come from source. This should be
-- investigated some time, since it should not be needed ???
if Comes_From_Source (Old_Formal)
and then
Comes_From_Source (New_Formal)
then
Conformance_Error
("\null exclusion for & does not match", New_Formal);
-- Mark error posted on the new formal to avoid duplicated
-- complaint about types not matching.
Set_Error_Posted (New_Formal);
end if;
end if;
end if;
-- Ada 2005 (AI-423): Possible access [sub]type and itype match. This
-- case occurs whenever a subprogram is being renamed and one of its
-- parameters imposes a null exclusion. For example:
-- type T is null record;
-- type Acc_T is access T;
-- subtype Acc_T_Sub is Acc_T;
-- procedure P (Obj : not null Acc_T_Sub); -- itype
-- procedure Ren_P (Obj : Acc_T_Sub) -- subtype
-- renames P;
Old_Formal_Base := Etype (Old_Formal);
New_Formal_Base := Etype (New_Formal);
if Get_Inst then
Old_Formal_Base := Get_Instance_Of (Old_Formal_Base);
New_Formal_Base := Get_Instance_Of (New_Formal_Base);
end if;
Access_Types_Match := Ada_Version >= Ada_2005
-- Ensure that this rule is only applied when New_Id is a
-- renaming of Old_Id.
and then Nkind (Parent (Parent (New_Id))) =
N_Subprogram_Renaming_Declaration
and then Nkind (Name (Parent (Parent (New_Id)))) in N_Has_Entity
and then Present (Entity (Name (Parent (Parent (New_Id)))))
and then Entity (Name (Parent (Parent (New_Id)))) = Old_Id
-- Now handle the allowed access-type case
and then Is_Access_Type (Old_Formal_Base)
and then Is_Access_Type (New_Formal_Base)
-- The type kinds must match. The only exception occurs with
-- multiple generics of the form:
-- generic generic
-- type F is private; type A is private;
-- type F_Ptr is access F; type A_Ptr is access A;
-- with proc F_P (X : F_Ptr); with proc A_P (X : A_Ptr);
-- package F_Pack is ... package A_Pack is
-- package F_Inst is
-- new F_Pack (A, A_Ptr, A_P);
-- When checking for conformance between the parameters of A_P
-- and F_P, the type kinds of F_Ptr and A_Ptr will not match
-- because the compiler has transformed A_Ptr into a subtype of
-- F_Ptr. We catch this case in the code below.
and then (Ekind (Old_Formal_Base) = Ekind (New_Formal_Base)
or else
(Is_Generic_Type (Old_Formal_Base)
and then Is_Generic_Type (New_Formal_Base)
and then Is_Internal (New_Formal_Base)
and then Etype (Etype (New_Formal_Base)) =
Old_Formal_Base))
and then Directly_Designated_Type (Old_Formal_Base) =
Directly_Designated_Type (New_Formal_Base)
and then ((Is_Itype (Old_Formal_Base)
and then Can_Never_Be_Null (Old_Formal_Base))
or else
(Is_Itype (New_Formal_Base)
and then Can_Never_Be_Null (New_Formal_Base)));
-- Types must always match. In the visible part of an instance,
-- usual overloading rules for dispatching operations apply, and
-- we check base types (not the actual subtypes).
if In_Instance_Visible_Part
and then Is_Dispatching_Operation (New_Id)
then
if not Conforming_Types
(T1 => Base_Type (Etype (Old_Formal)),
T2 => Base_Type (Etype (New_Formal)),
Ctype => Ctype,
Get_Inst => Get_Inst)
and then not Access_Types_Match
then
Conformance_Error ("\type of & does not match!", New_Formal);
return;
end if;
elsif not Conforming_Types
(T1 => Old_Formal_Base,
T2 => New_Formal_Base,
Ctype => Ctype,
Get_Inst => Get_Inst)
and then not Access_Types_Match
then
-- Don't give error message if old type is Any_Type. This test
-- avoids some cascaded errors, e.g. in case of a bad spec.
if Errmsg and then Old_Formal_Base = Any_Type then
Conforms := False;
else
Conformance_Error ("\type of & does not match!", New_Formal);
end if;
return;
end if;
-- For mode conformance, mode must match
if Ctype >= Mode_Conformant then
if Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal) then
if not Ekind_In (New_Id, E_Function, E_Procedure)
or else not Is_Primitive_Wrapper (New_Id)
then
Conformance_Error ("\mode of & does not match!", New_Formal);
else
declare
T : constant Entity_Id := Find_Dispatching_Type (New_Id);
begin
if Is_Protected_Type
(Corresponding_Concurrent_Type (T))
then
Error_Msg_PT (T, New_Id);
else
Conformance_Error
("\mode of & does not match!", New_Formal);
end if;
end;
end if;
return;
-- Part of mode conformance for access types is having the same
-- constant modifier.
elsif Access_Types_Match
and then Is_Access_Constant (Old_Formal_Base) /=
Is_Access_Constant (New_Formal_Base)
then
Conformance_Error
("\constant modifier does not match!", New_Formal);
return;
end if;
end if;
if Ctype >= Subtype_Conformant then
-- Ada 2005 (AI-231): In case of anonymous access types check
-- the null-exclusion and access-to-constant attributes must
-- match. For null exclusion, we test the types rather than the
-- formals themselves, since the attribute is only set reliably
-- on the formals in the Ada 95 case, and we exclude the case
-- where Old_Formal is marked as controlling, to avoid errors
-- when matching completing bodies with dispatching declarations
-- (access formals in the bodies aren't marked Can_Never_Be_Null).
if Ada_Version >= Ada_2005
and then Ekind (Etype (Old_Formal)) = E_Anonymous_Access_Type
and then Ekind (Etype (New_Formal)) = E_Anonymous_Access_Type
and then
((Can_Never_Be_Null (Etype (Old_Formal)) /=
Can_Never_Be_Null (Etype (New_Formal))
and then
not Is_Controlling_Formal (Old_Formal))
or else
Is_Access_Constant (Etype (Old_Formal)) /=
Is_Access_Constant (Etype (New_Formal)))
-- Do not complain if error already posted on New_Formal. This
-- avoids some redundant error messages.
and then not Error_Posted (New_Formal)
then
-- It is allowed to omit the null-exclusion in case of stream
-- attribute subprograms. We recognize stream subprograms
-- through their TSS-generated suffix.
declare
TSS_Name : constant TSS_Name_Type := Get_TSS_Name (New_Id);
begin
if TSS_Name /= TSS_Stream_Read
and then TSS_Name /= TSS_Stream_Write
and then TSS_Name /= TSS_Stream_Input
and then TSS_Name /= TSS_Stream_Output
then
-- Here we have a definite conformance error. It is worth
-- special casing the error message for the case of a
-- controlling formal (which excludes null).
if Is_Controlling_Formal (New_Formal) then
Error_Msg_Node_2 := Scope (New_Formal);
Conformance_Error
("\controlling formal& of& excludes null, "
& "declaration must exclude null as well",
New_Formal);
-- Normal case (couldn't we give more detail here???)
else
Conformance_Error
("\type of & does not match!", New_Formal);
end if;
return;
end if;
end;
end if;
end if;
-- Full conformance checks
if Ctype = Fully_Conformant then
-- We have checked already that names match
if Parameter_Mode (Old_Formal) = E_In_Parameter then
-- Check default expressions for in parameters
declare
NewD : constant Boolean :=
Present (Default_Value (New_Formal));
OldD : constant Boolean :=
Present (Default_Value (Old_Formal));
begin
if NewD or OldD then
-- The old default value has been analyzed because the
-- current full declaration will have frozen everything
-- before. The new default value has not been analyzed,
-- so analyze it now before we check for conformance.
if NewD then
Push_Scope (New_Id);
Preanalyze_Spec_Expression
(Default_Value (New_Formal), Etype (New_Formal));
End_Scope;
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Default_Value (Old_Formal),
Default_Value (New_Formal))
then
Conformance_Error
("\default expression for & does not match!",
New_Formal);
return;
end if;
end if;
end;
end if;
end if;
-- A couple of special checks for Ada 83 mode. These checks are
-- skipped if either entity is an operator in package Standard,
-- or if either old or new instance is not from the source program.
if Ada_Version = Ada_83
and then Sloc (Old_Id) > Standard_Location
and then Sloc (New_Id) > Standard_Location
and then Comes_From_Source (Old_Id)
and then Comes_From_Source (New_Id)
then
declare
Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
New_Param : constant Node_Id := Declaration_Node (New_Formal);
begin
-- Explicit IN must be present or absent in both cases. This
-- test is required only in the full conformance case.
if In_Present (Old_Param) /= In_Present (New_Param)
and then Ctype = Fully_Conformant
then
Conformance_Error
("\(Ada 83) IN must appear in both declarations",
New_Formal);
return;
end if;
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A, B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Param) /= More_Ids (New_Param)
or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
then
Conformance_Error
("\grouping of & does not match!", New_Formal);
return;
end if;
end;
end if;
-- This label is required when skipping controlling formals
<<Skip_Controlling_Formal>>
Next_Formal (Old_Formal);
Next_Formal (New_Formal);
end loop;
if Present (Old_Formal) then
Conformance_Error ("\too few parameters!");
return;
elsif Present (New_Formal) then
Conformance_Error ("\too many parameters!", New_Formal);
return;
end if;
end Check_Conformance;
-----------------------
-- Check_Conventions --
-----------------------
procedure Check_Conventions (Typ : Entity_Id) is
Ifaces_List : Elist_Id;
procedure Check_Convention (Op : Entity_Id);
-- Verify that the convention of inherited dispatching operation Op is
-- consistent among all subprograms it overrides. In order to minimize
-- the search, Search_From is utilized to designate a specific point in
-- the list rather than iterating over the whole list once more.
----------------------
-- Check_Convention --
----------------------
procedure Check_Convention (Op : Entity_Id) is
function Convention_Of (Id : Entity_Id) return Convention_Id;
-- Given an entity, return its convention. The function treats Ghost
-- as convention Ada because the two have the same dynamic semantics.
-------------------
-- Convention_Of --
-------------------
function Convention_Of (Id : Entity_Id) return Convention_Id is
Conv : constant Convention_Id := Convention (Id);
begin
if Conv = Convention_Ghost then
return Convention_Ada;
else
return Conv;
end if;
end Convention_Of;
-- Local variables
Op_Conv : constant Convention_Id := Convention_Of (Op);
Iface_Conv : Convention_Id;
Iface_Elmt : Elmt_Id;
Iface_Prim_Elmt : Elmt_Id;
Iface_Prim : Entity_Id;
-- Start of processing for Check_Convention
begin
Iface_Elmt := First_Elmt (Ifaces_List);
while Present (Iface_Elmt) loop
Iface_Prim_Elmt :=
First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
while Present (Iface_Prim_Elmt) loop
Iface_Prim := Node (Iface_Prim_Elmt);
Iface_Conv := Convention_Of (Iface_Prim);
if Is_Interface_Conformant (Typ, Iface_Prim, Op)
and then Iface_Conv /= Op_Conv
then
Error_Msg_N
("inconsistent conventions in primitive operations", Typ);
Error_Msg_Name_1 := Chars (Op);
Error_Msg_Name_2 := Get_Convention_Name (Op_Conv);
Error_Msg_Sloc := Sloc (Op);
if Comes_From_Source (Op) or else No (Alias (Op)) then
if not Present (Overridden_Operation (Op)) then
Error_Msg_N ("\\primitive % defined #", Typ);
else
Error_Msg_N
("\\overriding operation % with " &
"convention % defined #", Typ);
end if;
else pragma Assert (Present (Alias (Op)));
Error_Msg_Sloc := Sloc (Alias (Op));
Error_Msg_N
("\\inherited operation % with " &
"convention % defined #", Typ);
end if;
Error_Msg_Name_1 := Chars (Op);
Error_Msg_Name_2 := Get_Convention_Name (Iface_Conv);
Error_Msg_Sloc := Sloc (Iface_Prim);
Error_Msg_N
("\\overridden operation % with " &
"convention % defined #", Typ);
-- Avoid cascading errors
return;
end if;
Next_Elmt (Iface_Prim_Elmt);
end loop;
Next_Elmt (Iface_Elmt);
end loop;
end Check_Convention;
-- Local variables
Prim_Op : Entity_Id;
Prim_Op_Elmt : Elmt_Id;
-- Start of processing for Check_Conventions
begin
if not Has_Interfaces (Typ) then
return;
end if;
Collect_Interfaces (Typ, Ifaces_List);
-- The algorithm checks every overriding dispatching operation against
-- all the corresponding overridden dispatching operations, detecting
-- differences in conventions.
Prim_Op_Elmt := First_Elmt (Primitive_Operations (Typ));
while Present (Prim_Op_Elmt) loop
Prim_Op := Node (Prim_Op_Elmt);
-- A small optimization: skip the predefined dispatching operations
-- since they always have the same convention.
if not Is_Predefined_Dispatching_Operation (Prim_Op) then
Check_Convention (Prim_Op);
end if;
Next_Elmt (Prim_Op_Elmt);
end loop;
end Check_Conventions;
------------------------------
-- Check_Delayed_Subprogram --
------------------------------
procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
F : Entity_Id;
procedure Possible_Freeze (T : Entity_Id);
-- T is the type of either a formal parameter or of the return type.
-- If T is not yet frozen and needs a delayed freeze, then the
-- subprogram itself must be delayed. If T is the limited view of an
-- incomplete type the subprogram must be frozen as well, because
-- T may depend on local types that have not been frozen yet.
---------------------
-- Possible_Freeze --
---------------------
procedure Possible_Freeze (T : Entity_Id) is
begin
if Has_Delayed_Freeze (T) and then not Is_Frozen (T) then
Set_Has_Delayed_Freeze (Designator);
elsif Is_Access_Type (T)
and then Has_Delayed_Freeze (Designated_Type (T))
and then not Is_Frozen (Designated_Type (T))
then
Set_Has_Delayed_Freeze (Designator);
elsif Ekind (T) = E_Incomplete_Type and then From_With_Type (T) then
Set_Has_Delayed_Freeze (Designator);
-- AI05-0151: In Ada 2012, Incomplete types can appear in the profile
-- of a subprogram or entry declaration.
elsif Ekind (T) = E_Incomplete_Type
and then Ada_Version >= Ada_2012
then
Set_Has_Delayed_Freeze (Designator);
end if;
end Possible_Freeze;
-- Start of processing for Check_Delayed_Subprogram
begin
-- All subprograms, including abstract subprograms, may need a freeze
-- node if some formal type or the return type needs one.
Possible_Freeze (Etype (Designator));
Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
-- Need delayed freeze if any of the formal types themselves need
-- a delayed freeze and are not yet frozen.
F := First_Formal (Designator);
while Present (F) loop
Possible_Freeze (Etype (F));
Possible_Freeze (Base_Type (Etype (F))); -- needed ???
Next_Formal (F);
end loop;
-- Mark functions that return by reference. Note that it cannot be
-- done for delayed_freeze subprograms because the underlying
-- returned type may not be known yet (for private types)
if not Has_Delayed_Freeze (Designator) and then Expander_Active then
declare
Typ : constant Entity_Id := Etype (Designator);
Utyp : constant Entity_Id := Underlying_Type (Typ);
begin
if Is_Immutably_Limited_Type (Typ) then
Set_Returns_By_Ref (Designator);
elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
Set_Returns_By_Ref (Designator);
end if;
end;
end if;
end Check_Delayed_Subprogram;
------------------------------------
-- Check_Discriminant_Conformance --
------------------------------------
procedure Check_Discriminant_Conformance
(N : Node_Id;
Prev : Entity_Id;
Prev_Loc : Node_Id)
is
Old_Discr : Entity_Id := First_Discriminant (Prev);
New_Discr : Node_Id := First (Discriminant_Specifications (N));
New_Discr_Id : Entity_Id;
New_Discr_Type : Entity_Id;
procedure Conformance_Error (Msg : String; N : Node_Id);
-- Post error message for conformance error on given node. Two messages
-- are output. The first points to the previous declaration with a
-- general "no conformance" message. The second is the detailed reason,
-- supplied as Msg. The parameter N provide information for a possible
-- & insertion in the message.
-----------------------
-- Conformance_Error --
-----------------------
procedure Conformance_Error (Msg : String; N : Node_Id) is
begin
Error_Msg_Sloc := Sloc (Prev_Loc);
Error_Msg_N -- CODEFIX
("not fully conformant with declaration#!", N);
Error_Msg_NE (Msg, N, N);
end Conformance_Error;
-- Start of processing for Check_Discriminant_Conformance
begin
while Present (Old_Discr) and then Present (New_Discr) loop
New_Discr_Id := Defining_Identifier (New_Discr);
-- The subtype mark of the discriminant on the full type has not
-- been analyzed so we do it here. For an access discriminant a new
-- type is created.
if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
New_Discr_Type :=
Access_Definition (N, Discriminant_Type (New_Discr));
else
Analyze (Discriminant_Type (New_Discr));
New_Discr_Type := Etype (Discriminant_Type (New_Discr));
-- Ada 2005: if the discriminant definition carries a null
-- exclusion, create an itype to check properly for consistency
-- with partial declaration.
if Is_Access_Type (New_Discr_Type)
and then Null_Exclusion_Present (New_Discr)
then
New_Discr_Type :=
Create_Null_Excluding_Itype
(T => New_Discr_Type,
Related_Nod => New_Discr,
Scope_Id => Current_Scope);
end if;
end if;
if not Conforming_Types
(Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
then
Conformance_Error ("type of & does not match!", New_Discr_Id);
return;
else
-- Treat the new discriminant as an occurrence of the old one,
-- for navigation purposes, and fill in some semantic
-- information, for completeness.
Generate_Reference (Old_Discr, New_Discr_Id, 'r');
Set_Etype (New_Discr_Id, Etype (Old_Discr));
Set_Scope (New_Discr_Id, Scope (Old_Discr));
end if;
-- Names must match
if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
Conformance_Error ("name & does not match!", New_Discr_Id);
return;
end if;
-- Default expressions must match
declare
NewD : constant Boolean :=
Present (Expression (New_Discr));
OldD : constant Boolean :=
Present (Expression (Parent (Old_Discr)));
begin
if NewD or OldD then
-- The old default value has been analyzed and expanded,
-- because the current full declaration will have frozen
-- everything before. The new default values have not been
-- expanded, so expand now to check conformance.
if NewD then
Preanalyze_Spec_Expression
(Expression (New_Discr), New_Discr_Type);
end if;
if not (NewD and OldD)
or else not Fully_Conformant_Expressions
(Expression (Parent (Old_Discr)),
Expression (New_Discr))
then
Conformance_Error
("default expression for & does not match!",
New_Discr_Id);
return;
end if;
end if;
end;
-- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
if Ada_Version = Ada_83 then
declare
Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
begin
-- Grouping (use of comma in param lists) must be the same
-- This is where we catch a misconformance like:
-- A, B : Integer
-- A : Integer; B : Integer
-- which are represented identically in the tree except
-- for the setting of the flags More_Ids and Prev_Ids.
if More_Ids (Old_Disc) /= More_Ids (New_Discr)
or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
then
Conformance_Error
("grouping of & does not match!", New_Discr_Id);
return;
end if;
end;
end if;
Next_Discriminant (Old_Discr);
Next (New_Discr);
end loop;
if Present (Old_Discr) then
Conformance_Error ("too few discriminants!", Defining_Identifier (N));
return;
elsif Present (New_Discr) then
Conformance_Error
("too many discriminants!", Defining_Identifier (New_Discr));
return;
end if;
end Check_Discriminant_Conformance;
----------------------------
-- Check_Fully_Conformant --
----------------------------
procedure Check_Fully_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
end Check_Fully_Conformant;
---------------------------
-- Check_Mode_Conformant --
---------------------------
procedure Check_Mode_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
end Check_Mode_Conformant;
--------------------------------
-- Check_Overriding_Indicator --
--------------------------------
procedure Check_Overriding_Indicator
(Subp : Entity_Id;
Overridden_Subp : Entity_Id;
Is_Primitive : Boolean)
is
Decl : Node_Id;
Spec : Node_Id;
begin
-- No overriding indicator for literals
if Ekind (Subp) = E_Enumeration_Literal then
return;
elsif Ekind (Subp) = E_Entry then
Decl := Parent (Subp);
-- No point in analyzing a malformed operator
elsif Nkind (Subp) = N_Defining_Operator_Symbol
and then Error_Posted (Subp)
then
return;
else
Decl := Unit_Declaration_Node (Subp);
end if;
if Nkind_In (Decl, N_Subprogram_Body,
N_Subprogram_Body_Stub,
N_Subprogram_Declaration,
N_Abstract_Subprogram_Declaration,
N_Subprogram_Renaming_Declaration)
then
Spec := Specification (Decl);
elsif Nkind (Decl) = N_Entry_Declaration then
Spec := Decl;
else
return;
end if;
-- The overriding operation is type conformant with the overridden one,
-- but the names of the formals are not required to match. If the names
-- appear permuted in the overriding operation, this is a possible
-- source of confusion that is worth diagnosing. Controlling formals
-- often carry names that reflect the type, and it is not worthwhile
-- requiring that their names match.
if Present (Overridden_Subp)
and then Nkind (Subp) /= N_Defining_Operator_Symbol
then
declare
Form1 : Entity_Id;
Form2 : Entity_Id;
begin
Form1 := First_Formal (Subp);
Form2 := First_Formal (Overridden_Subp);
-- If the overriding operation is a synchronized operation, skip
-- the first parameter of the overridden operation, which is
-- implicit in the new one. If the operation is declared in the
-- body it is not primitive and all formals must match.
if Is_Concurrent_Type (Scope (Subp))
and then Is_Tagged_Type (Scope (Subp))
and then not Has_Completion (Scope (Subp))
then
Form2 := Next_Formal (Form2);
end if;
if Present (Form1) then
Form1 := Next_Formal (Form1);
Form2 := Next_Formal (Form2);
end if;
while Present (Form1) loop
if not Is_Controlling_Formal (Form1)
and then Present (Next_Formal (Form2))
and then Chars (Form1) = Chars (Next_Formal (Form2))
then
Error_Msg_Node_2 := Alias (Overridden_Subp);
Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
Error_Msg_NE
("& does not match corresponding formal of&#",
Form1, Form1);
exit;
end if;
Next_Formal (Form1);
Next_Formal (Form2);
end loop;
end;
end if;
-- If there is an overridden subprogram, then check that there is no
-- "not overriding" indicator, and mark the subprogram as overriding.
-- This is not done if the overridden subprogram is marked as hidden,
-- which can occur for the case of inherited controlled operations
-- (see Derive_Subprogram), unless the inherited subprogram's parent
-- subprogram is not itself hidden. (Note: This condition could probably
-- be simplified, leaving out the testing for the specific controlled
-- cases, but it seems safer and clearer this way, and echoes similar
-- special-case tests of this kind in other places.)
if Present (Overridden_Subp)
and then (not Is_Hidden (Overridden_Subp)
or else
(Nam_In (Chars (Overridden_Subp), Name_Initialize,
Name_Adjust,
Name_Finalize)
and then Present (Alias (Overridden_Subp))
and then not Is_Hidden (Alias (Overridden_Subp))))
then
if Must_Not_Override (Spec) then
Error_Msg_Sloc := Sloc (Overridden_Subp);
if Ekind (Subp) = E_Entry then
Error_Msg_NE
("entry & overrides inherited operation #", Spec, Subp);
else
Error_Msg_NE
("subprogram & overrides inherited operation #", Spec, Subp);
end if;
-- Special-case to fix a GNAT oddity: Limited_Controlled is declared
-- as an extension of Root_Controlled, and thus has a useless Adjust
-- operation. This operation should not be inherited by other limited
-- controlled types. An explicit Adjust for them is not overriding.
elsif Must_Override (Spec)
and then Chars (Overridden_Subp) = Name_Adjust
and then Is_Limited_Type (Etype (First_Formal (Subp)))
and then Present (Alias (Overridden_Subp))
and then
Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Alias (Overridden_Subp))))
then
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
elsif Is_Subprogram (Subp) then
if Is_Init_Proc (Subp) then
null;
elsif No (Overridden_Operation (Subp)) then
-- For entities generated by Derive_Subprograms the overridden
-- operation is the inherited primitive (which is available
-- through the attribute alias)
if (Is_Dispatching_Operation (Subp)
or else Is_Dispatching_Operation (Overridden_Subp))
and then not Comes_From_Source (Overridden_Subp)
and then Find_Dispatching_Type (Overridden_Subp) =
Find_Dispatching_Type (Subp)
and then Present (Alias (Overridden_Subp))
and then Comes_From_Source (Alias (Overridden_Subp))
then
Set_Overridden_Operation (Subp, Alias (Overridden_Subp));
else
Set_Overridden_Operation (Subp, Overridden_Subp);
end if;
end if;
end if;
-- If primitive flag is set or this is a protected operation, then
-- the operation is overriding at the point of its declaration, so
-- warn if necessary. Otherwise it may have been declared before the
-- operation it overrides and no check is required.
if Style_Check
and then not Must_Override (Spec)
and then (Is_Primitive
or else Ekind (Scope (Subp)) = E_Protected_Type)
then
Style.Missing_Overriding (Decl, Subp);
end if;
-- If Subp is an operator, it may override a predefined operation, if
-- it is defined in the same scope as the type to which it applies.
-- In that case Overridden_Subp is empty because of our implicit
-- representation for predefined operators. We have to check whether the
-- signature of Subp matches that of a predefined operator. Note that
-- first argument provides the name of the operator, and the second
-- argument the signature that may match that of a standard operation.
-- If the indicator is overriding, then the operator must match a
-- predefined signature, because we know already that there is no
-- explicit overridden operation.
elsif Nkind (Subp) = N_Defining_Operator_Symbol then
if Must_Not_Override (Spec) then
-- If this is not a primitive or a protected subprogram, then
-- "not overriding" is illegal.
if not Is_Primitive
and then Ekind (Scope (Subp)) /= E_Protected_Type
then
Error_Msg_N
("overriding indicator only allowed "
& "if subprogram is primitive", Subp);
elsif Can_Override_Operator (Subp) then
Error_Msg_NE
("subprogram& overrides predefined operator ", Spec, Subp);
end if;
elsif Must_Override (Spec) then
if No (Overridden_Operation (Subp))
and then not Can_Override_Operator (Subp)
then
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
end if;
elsif not Error_Posted (Subp)
and then Style_Check
and then Can_Override_Operator (Subp)
and then
not Is_Predefined_File_Name
(Unit_File_Name (Get_Source_Unit (Subp)))
then
-- If style checks are enabled, indicate that the indicator is
-- missing. However, at the point of declaration, the type of
-- which this is a primitive operation may be private, in which
-- case the indicator would be premature.
if Has_Private_Declaration (Etype (Subp))
or else Has_Private_Declaration (Etype (First_Formal (Subp)))
then
null;
else
Style.Missing_Overriding (Decl, Subp);
end if;
end if;
elsif Must_Override (Spec) then
if Ekind (Subp) = E_Entry then
Error_Msg_NE ("entry & is not overriding", Spec, Subp);
else
Error_Msg_NE ("subprogram & is not overriding", Spec, Subp);
end if;
-- If the operation is marked "not overriding" and it's not primitive
-- then an error is issued, unless this is an operation of a task or
-- protected type (RM05-8.3.1(3/2-4/2)). Error cases where "overriding"
-- has been specified have already been checked above.
elsif Must_Not_Override (Spec)
and then not Is_Primitive
and then Ekind (Subp) /= E_Entry
and then Ekind (Scope (Subp)) /= E_Protected_Type
then
Error_Msg_N
("overriding indicator only allowed if subprogram is primitive",
Subp);
return;
end if;
end Check_Overriding_Indicator;
-------------------
-- Check_Returns --
-------------------
-- Note: this procedure needs to know far too much about how the expander
-- messes with exceptions. The use of the flag Exception_Junk and the
-- incorporation of knowledge of Exp_Ch11.Expand_Local_Exception_Handlers
-- works, but is not very clean. It would be better if the expansion
-- routines would leave Original_Node working nicely, and we could use
-- Original_Node here to ignore all the peculiar expander messing ???
procedure Check_Returns
(HSS : Node_Id;
Mode : Character;
Err : out Boolean;
Proc : Entity_Id := Empty)
is
Handler : Node_Id;
procedure Check_Statement_Sequence (L : List_Id);
-- Internal recursive procedure to check a list of statements for proper
-- termination by a return statement (or a transfer of control or a
-- compound statement that is itself internally properly terminated).
------------------------------
-- Check_Statement_Sequence --
------------------------------
procedure Check_Statement_Sequence (L : List_Id) is
Last_Stm : Node_Id;
Stm : Node_Id;
Kind : Node_Kind;
Raise_Exception_Call : Boolean;
-- Set True if statement sequence terminated by Raise_Exception call
-- or a Reraise_Occurrence call.
begin
Raise_Exception_Call := False;
-- Get last real statement
Last_Stm := Last (L);
-- Deal with digging out exception handler statement sequences that
-- have been transformed by the local raise to goto optimization.
-- See Exp_Ch11.Expand_Local_Exception_Handlers for details. If this
-- optimization has occurred, we are looking at something like:
-- begin
-- original stmts in block
-- exception \
-- when excep1 => |
-- goto L1; | omitted if No_Exception_Propagation
-- when excep2 => |
-- goto L2; /
-- end;
-- goto L3; -- skip handler when exception not raised
-- <<L1>> -- target label for local exception
-- begin
-- estmts1
-- end;
-- goto L3;
-- <<L2>>
-- begin
-- estmts2
-- end;
-- <<L3>>
-- and what we have to do is to dig out the estmts1 and estmts2
-- sequences (which were the original sequences of statements in
-- the exception handlers) and check them.
if Nkind (Last_Stm) = N_Label and then Exception_Junk (Last_Stm) then
Stm := Last_Stm;
loop
Prev (Stm);
exit when No (Stm);
exit when Nkind (Stm) /= N_Block_Statement;
exit when not Exception_Junk (Stm);
Prev (Stm);
exit when No (Stm);
exit when Nkind (Stm) /= N_Label;
exit when not Exception_Junk (Stm);
Check_Statement_Sequence
(Statements (Handled_Statement_Sequence (Next (Stm))));
Prev (Stm);
Last_Stm := Stm;
exit when No (Stm);
exit when Nkind (Stm) /= N_Goto_Statement;
exit when not Exception_Junk (Stm);
end loop;
end if;
-- Don't count pragmas
while Nkind (Last_Stm) = N_Pragma
-- Don't count call to SS_Release (can happen after Raise_Exception)
or else
(Nkind (Last_Stm) = N_Procedure_Call_Statement
and then
Nkind (Name (Last_Stm)) = N_Identifier
and then
Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
-- Don't count exception junk
or else
(Nkind_In (Last_Stm, N_Goto_Statement,
N_Label,
N_Object_Declaration)
and then Exception_Junk (Last_Stm))
or else Nkind (Last_Stm) in N_Push_xxx_Label
or else Nkind (Last_Stm) in N_Pop_xxx_Label
-- Inserted code, such as finalization calls, is irrelevant: we only
-- need to check original source.
or else Is_Rewrite_Insertion (Last_Stm)
loop
Prev (Last_Stm);
end loop;
-- Here we have the "real" last statement
Kind := Nkind (Last_Stm);
-- Transfer of control, OK. Note that in the No_Return procedure
-- case, we already diagnosed any explicit return statements, so
-- we can treat them as OK in this context.
if Is_Transfer (Last_Stm) then
return;
-- Check cases of explicit non-indirect procedure calls
elsif Kind = N_Procedure_Call_Statement
and then Is_Entity_Name (Name (Last_Stm))
then
-- Check call to Raise_Exception procedure which is treated
-- specially, as is a call to Reraise_Occurrence.
-- We suppress the warning in these cases since it is likely that
-- the programmer really does not expect to deal with the case
-- of Null_Occurrence, and thus would find a warning about a
-- missing return curious, and raising Program_Error does not
-- seem such a bad behavior if this does occur.
-- Note that in the Ada 2005 case for Raise_Exception, the actual
-- behavior will be to raise Constraint_Error (see AI-329).
if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
or else
Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
then
Raise_Exception_Call := True;
-- For Raise_Exception call, test first argument, if it is
-- an attribute reference for a 'Identity call, then we know
-- that the call cannot possibly return.
declare
Arg : constant Node_Id :=
Original_Node (First_Actual (Last_Stm));
begin
if Nkind (Arg) = N_Attribute_Reference
and then Attribute_Name (Arg) = Name_Identity
then
return;
end if;
end;
end if;
-- If statement, need to look inside if there is an else and check
-- each constituent statement sequence for proper termination.
elsif Kind = N_If_Statement
and then Present (Else_Statements (Last_Stm))
then
Check_Statement_Sequence (Then_Statements (Last_Stm));
Check_Statement_Sequence (Else_Statements (Last_Stm));
if Present (Elsif_Parts (Last_Stm)) then
declare
Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
begin
while Present (Elsif_Part) loop
Check_Statement_Sequence (Then_Statements (Elsif_Part));
Next (Elsif_Part);
end loop;
end;
end if;
return;
-- Case statement, check each case for proper termination
elsif Kind = N_Case_Statement then
declare
Case_Alt : Node_Id;
begin
Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
while Present (Case_Alt) loop
Check_Statement_Sequence (Statements (Case_Alt));
Next_Non_Pragma (Case_Alt);
end loop;
end;
return;
-- Block statement, check its handled sequence of statements
elsif Kind = N_Block_Statement then
declare
Err1 : Boolean;
begin
Check_Returns
(Handled_Statement_Sequence (Last_Stm), Mode, Err1);
if Err1 then
Err := True;
end if;
return;
end;
-- Loop statement. If there is an iteration scheme, we can definitely
-- fall out of the loop. Similarly if there is an exit statement, we
-- can fall out. In either case we need a following return.
elsif Kind = N_Loop_Statement then
if Present (Iteration_Scheme (Last_Stm))
or else Has_Exit (Entity (Identifier (Last_Stm)))
then
null;
-- A loop with no exit statement or iteration scheme is either
-- an infinite loop, or it has some other exit (raise/return).
-- In either case, no warning is required.
else
return;
end if;
-- Timed entry call, check entry call and delay alternatives
-- Note: in expanded code, the timed entry call has been converted
-- to a set of expanded statements on which the check will work
-- correctly in any case.
elsif Kind = N_Timed_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
DCA : constant Node_Id := Delay_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- If statement sequence of delay alternative is missing, then
-- we can definitely fall through, and we post the error
-- message on the delay alternative itself.
-- Note: if both ECA and DCA are missing the return, then we
-- post only one message, should be enough to fix the bugs.
-- If not we will get a message next time on the DCA when the
-- ECA is fixed!
elsif No (Statements (DCA)) then
Last_Stm := DCA;
-- Else check both statement sequences
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Statements (DCA));
return;
end if;
end;
-- Conditional entry call, check entry call and else part
-- Note: in expanded code, the conditional entry call has been
-- converted to a set of expanded statements on which the check
-- will work correctly in any case.
elsif Kind = N_Conditional_Entry_Call then
declare
ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
begin
-- If statement sequence of entry call alternative is missing,
-- then we can definitely fall through, and we post the error
-- message on the entry call alternative itself.
if No (Statements (ECA)) then
Last_Stm := ECA;
-- Else check statement sequence and else part
else
Check_Statement_Sequence (Statements (ECA));
Check_Statement_Sequence (Else_Statements (Last_Stm));
return;
end if;
end;
end if;
-- If we fall through, issue appropriate message
if Mode = 'F' then
if not Raise_Exception_Call then
Error_Msg_N
("RETURN statement missing following this statement??!",
Last_Stm);
Error_Msg_N
("\Program_Error may be raised at run time??!",
Last_Stm);
end if;
-- Note: we set Err even though we have not issued a warning
-- because we still have a case of a missing return. This is
-- an extremely marginal case, probably will never be noticed
-- but we might as well get it right.
Err := True;
-- Otherwise we have the case of a procedure marked No_Return
else
if not Raise_Exception_Call then
Error_Msg_N
("implied return after this statement " &
"will raise Program_Error??",
Last_Stm);
Error_Msg_NE
("\procedure & is marked as No_Return??!",
Last_Stm, Proc);
end if;
declare
RE : constant Node_Id :=
Make_Raise_Program_Error (Sloc (Last_Stm),
Reason => PE_Implicit_Return);
begin
Insert_After (Last_Stm, RE);
Analyze (RE);
end;
end if;
end Check_Statement_Sequence;
-- Start of processing for Check_Returns
begin
Err := False;
Check_Statement_Sequence (Statements (HSS));
if Present (Exception_Handlers (HSS)) then
Handler := First_Non_Pragma (Exception_Handlers (HSS));
while Present (Handler) loop
Check_Statement_Sequence (Statements (Handler));
Next_Non_Pragma (Handler);
end loop;
end if;
end Check_Returns;
----------------------------
-- Check_Subprogram_Order --
----------------------------
procedure Check_Subprogram_Order (N : Node_Id) is
function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
-- This is used to check if S1 > S2 in the sense required by this test,
-- for example nameab < namec, but name2 < name10.
-----------------------------
-- Subprogram_Name_Greater --
-----------------------------
function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
L1, L2 : Positive;
N1, N2 : Natural;
begin
-- Deal with special case where names are identical except for a
-- numerical suffix. These are handled specially, taking the numeric
-- ordering from the suffix into account.
L1 := S1'Last;
while S1 (L1) in '0' .. '9' loop
L1 := L1 - 1;
end loop;
L2 := S2'Last;
while S2 (L2) in '0' .. '9' loop
L2 := L2 - 1;
end loop;
-- If non-numeric parts non-equal, do straight compare
if S1 (S1'First .. L1) /= S2 (S2'First .. L2) then
return S1 > S2;
-- If non-numeric parts equal, compare suffixed numeric parts. Note
-- that a missing suffix is treated as numeric zero in this test.
else
N1 := 0;
while L1 < S1'Last loop
L1 := L1 + 1;
N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
end loop;
N2 := 0;
while L2 < S2'Last loop
L2 := L2 + 1;
N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
end loop;
return N1 > N2;
end if;
end Subprogram_Name_Greater;
-- Start of processing for Check_Subprogram_Order
begin
-- Check body in alpha order if this is option
if Style_Check
and then Style_Check_Order_Subprograms
and then Nkind (N) = N_Subprogram_Body
and then Comes_From_Source (N)
and then In_Extended_Main_Source_Unit (N)
then
declare
LSN : String_Ptr
renames Scope_Stack.Table
(Scope_Stack.Last).Last_Subprogram_Name;
Body_Id : constant Entity_Id :=
Defining_Entity (Specification (N));
begin
Get_Decoded_Name_String (Chars (Body_Id));
if LSN /= null then
if Subprogram_Name_Greater
(LSN.all, Name_Buffer (1 .. Name_Len))
then
Style.Subprogram_Not_In_Alpha_Order (Body_Id);
end if;
Free (LSN);
end if;
LSN := new String'(Name_Buffer (1 .. Name_Len));
end;
end if;
end Check_Subprogram_Order;
------------------------------
-- Check_Subtype_Conformant --
------------------------------
procedure Check_Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Skip_Controlling_Formals : Boolean := False;
Get_Inst : Boolean := False)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc,
Skip_Controlling_Formals => Skip_Controlling_Formals,
Get_Inst => Get_Inst);
end Check_Subtype_Conformant;
---------------------------
-- Check_Type_Conformant --
---------------------------
procedure Check_Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty)
is
Result : Boolean;
pragma Warnings (Off, Result);
begin
Check_Conformance
(New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
end Check_Type_Conformant;
---------------------------
-- Can_Override_Operator --
---------------------------
function Can_Override_Operator (Subp : Entity_Id) return Boolean is
Typ : Entity_Id;
begin
if Nkind (Subp) /= N_Defining_Operator_Symbol then
return False;
else
Typ := Base_Type (Etype (First_Formal (Subp)));
-- Check explicitly that the operation is a primitive of the type
return Operator_Matches_Spec (Subp, Subp)
and then not Is_Generic_Type (Typ)
and then Scope (Subp) = Scope (Typ)
and then not Is_Class_Wide_Type (Typ);
end if;
end Can_Override_Operator;
----------------------
-- Conforming_Types --
----------------------
function Conforming_Types
(T1 : Entity_Id;
T2 : Entity_Id;
Ctype : Conformance_Type;
Get_Inst : Boolean := False) return Boolean
is
Type_1 : Entity_Id := T1;
Type_2 : Entity_Id := T2;
Are_Anonymous_Access_To_Subprogram_Types : Boolean := False;
function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
-- If neither T1 nor T2 are generic actual types, or if they are in
-- different scopes (e.g. parent and child instances), then verify that
-- the base types are equal. Otherwise T1 and T2 must be on the same
-- subtype chain. The whole purpose of this procedure is to prevent
-- spurious ambiguities in an instantiation that may arise if two
-- distinct generic types are instantiated with the same actual.
function Find_Designated_Type (T : Entity_Id) return Entity_Id;
-- An access parameter can designate an incomplete type. If the
-- incomplete type is the limited view of a type from a limited_
-- with_clause, check whether the non-limited view is available. If
-- it is a (non-limited) incomplete type, get the full view.
function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean;
-- Returns True if and only if either T1 denotes a limited view of T2
-- or T2 denotes a limited view of T1. This can arise when the limited
-- with view of a type is used in a subprogram declaration and the
-- subprogram body is in the scope of a regular with clause for the
-- same unit. In such a case, the two type entities can be considered
-- identical for purposes of conformance checking.
----------------------
-- Base_Types_Match --
----------------------
function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
BT1 : constant Entity_Id := Base_Type (T1);
BT2 : constant Entity_Id := Base_Type (T2);
begin
if T1 = T2 then
return True;
elsif BT1 = BT2 then
-- The following is too permissive. A more precise test should
-- check that the generic actual is an ancestor subtype of the
-- other ???.
-- See code in Find_Corresponding_Spec that applies an additional
-- filter to handle accidental amiguities in instances.
return not Is_Generic_Actual_Type (T1)
or else not Is_Generic_Actual_Type (T2)
or else Scope (T1) /= Scope (T2);
-- If T2 is a generic actual type it is declared as the subtype of
-- the actual. If that actual is itself a subtype we need to use its
-- own base type to check for compatibility.
elsif Ekind (BT2) = Ekind (T2) and then BT1 = Base_Type (BT2) then
return True;
elsif Ekind (BT1) = Ekind (T1) and then BT2 = Base_Type (BT1) then
return True;
else
return False;
end if;
end Base_Types_Match;
--------------------------
-- Find_Designated_Type --
--------------------------
function Find_Designated_Type (T : Entity_Id) return Entity_Id is
Desig : Entity_Id;
begin
Desig := Directly_Designated_Type (T);
if Ekind (Desig) = E_Incomplete_Type then
-- If regular incomplete type, get full view if available
if Present (Full_View (Desig)) then
Desig := Full_View (Desig);
-- If limited view of a type, get non-limited view if available,
-- and check again for a regular incomplete type.
elsif Present (Non_Limited_View (Desig)) then
Desig := Get_Full_View (Non_Limited_View (Desig));
end if;
end if;
return Desig;
end Find_Designated_Type;
-------------------------------
-- Matches_Limited_With_View --
-------------------------------
function Matches_Limited_With_View (T1, T2 : Entity_Id) return Boolean is
begin
-- In some cases a type imported through a limited_with clause, and
-- its nonlimited view are both visible, for example in an anonymous
-- access-to-class-wide type in a formal. Both entities designate the
-- same type.
if From_With_Type (T1) and then T2 = Available_View (T1) then
return True;
elsif From_With_Type (T2) and then T1 = Available_View (T2) then
return True;
elsif From_With_Type (T1)
and then From_With_Type (T2)
and then Available_View (T1) = Available_View (T2)
then
return True;
else
return False;
end if;
end Matches_Limited_With_View;
-- Start of processing for Conforming_Types
begin
-- The context is an instance association for a formal access-to-
-- subprogram type; the formal parameter types require mapping because
-- they may denote other formal parameters of the generic unit.
if Get_Inst then
Type_1 := Get_Instance_Of (T1);
Type_2 := Get_Instance_Of (T2);
end if;
-- If one of the types is a view of the other introduced by a limited
-- with clause, treat these as conforming for all purposes.
if Matches_Limited_With_View (T1, T2) then
return True;
elsif Base_Types_Match (Type_1, Type_2) then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Type_2);
elsif Is_Incomplete_Or_Private_Type (Type_1)
and then Present (Full_View (Type_1))
and then Base_Types_Match (Full_View (Type_1), Type_2)
then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
elsif Ekind (Type_2) = E_Incomplete_Type
and then Present (Full_View (Type_2))
and then Base_Types_Match (Type_1, Full_View (Type_2))
then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
elsif Is_Private_Type (Type_2)
and then In_Instance
and then Present (Full_View (Type_2))
and then Base_Types_Match (Type_1, Full_View (Type_2))
then
return Ctype <= Mode_Conformant
or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
end if;
-- Ada 2005 (AI-254): Anonymous access-to-subprogram types must be
-- treated recursively because they carry a signature. As far as
-- conformance is concerned, convention plays no role, and either
-- or both could be access to protected subprograms.
Are_Anonymous_Access_To_Subprogram_Types :=
Ekind_In (Type_1, E_Anonymous_Access_Subprogram_Type,
E_Anonymous_Access_Protected_Subprogram_Type)
and then
Ekind_In (Type_2, E_Anonymous_Access_Subprogram_Type,
E_Anonymous_Access_Protected_Subprogram_Type);
-- Test anonymous access type case. For this case, static subtype
-- matching is required for mode conformance (RM 6.3.1(15)). We check
-- the base types because we may have built internal subtype entities
-- to handle null-excluding types (see Process_Formals).
if (Ekind (Base_Type (Type_1)) = E_Anonymous_Access_Type
and then
Ekind (Base_Type (Type_2)) = E_Anonymous_Access_Type)
-- Ada 2005 (AI-254)
or else Are_Anonymous_Access_To_Subprogram_Types
then
declare
Desig_1 : Entity_Id;
Desig_2 : Entity_Id;
begin
-- In Ada 2005, access constant indicators must match for
-- subtype conformance.
if Ada_Version >= Ada_2005
and then Ctype >= Subtype_Conformant
and then
Is_Access_Constant (Type_1) /= Is_Access_Constant (Type_2)
then
return False;
end if;
Desig_1 := Find_Designated_Type (Type_1);
Desig_2 := Find_Designated_Type (Type_2);
-- If the context is an instance association for a formal
-- access-to-subprogram type; formal access parameter designated
-- types require mapping because they may denote other formal
-- parameters of the generic unit.
if Get_Inst then
Desig_1 := Get_Instance_Of (Desig_1);
Desig_2 := Get_Instance_Of (Desig_2);
end if;
-- It is possible for a Class_Wide_Type to be introduced for an
-- incomplete type, in which case there is a separate class_ wide
-- type for the full view. The types conform if their Etypes
-- conform, i.e. one may be the full view of the other. This can
-- only happen in the context of an access parameter, other uses
-- of an incomplete Class_Wide_Type are illegal.
if Is_Class_Wide_Type (Desig_1)
and then
Is_Class_Wide_Type (Desig_2)
then
return
Conforming_Types
(Etype (Base_Type (Desig_1)),
Etype (Base_Type (Desig_2)), Ctype);
elsif Are_Anonymous_Access_To_Subprogram_Types then
if Ada_Version < Ada_2005 then
return Ctype = Type_Conformant
or else
Subtypes_Statically_Match (Desig_1, Desig_2);
-- We must check the conformance of the signatures themselves
else
declare
Conformant : Boolean;
begin
Check_Conformance
(Desig_1, Desig_2, Ctype, False, Conformant);
return Conformant;
end;
end if;
else
return Base_Type (Desig_1) = Base_Type (Desig_2)
and then (Ctype = Type_Conformant
or else
Subtypes_Statically_Match (Desig_1, Desig_2));
end if;
end;
-- Otherwise definitely no match
else
if ((Ekind (Type_1) = E_Anonymous_Access_Type
and then Is_Access_Type (Type_2))
or else (Ekind (Type_2) = E_Anonymous_Access_Type
and then Is_Access_Type (Type_1)))
and then
Conforming_Types
(Designated_Type (Type_1), Designated_Type (Type_2), Ctype)
then
May_Hide_Profile := True;
end if;
return False;
end if;
end Conforming_Types;
--------------------------
-- Create_Extra_Formals --
--------------------------
procedure Create_Extra_Formals (E : Entity_Id) is
Formal : Entity_Id;
First_Extra : Entity_Id := Empty;
Last_Extra : Entity_Id;
Formal_Type : Entity_Id;
P_Formal : Entity_Id := Empty;
function Add_Extra_Formal
(Assoc_Entity : Entity_Id;
Typ : Entity_Id;
Scope : Entity_Id;
Suffix : String) return Entity_Id;
-- Add an extra formal to the current list of formals and extra formals.
-- The extra formal is added to the end of the list of extra formals,
-- and also returned as the result. These formals are always of mode IN.
-- The new formal has the type Typ, is declared in Scope, and its name
-- is given by a concatenation of the name of Assoc_Entity and Suffix.
-- The following suffixes are currently used. They should not be changed
-- without coordinating with CodePeer, which makes use of these to
-- provide better messages.
-- O denotes the Constrained bit.
-- L denotes the accessibility level.
-- BIP_xxx denotes an extra formal for a build-in-place function. See
-- the full list in exp_ch6.BIP_Formal_Kind.
----------------------
-- Add_Extra_Formal --
----------------------
function Add_Extra_Formal
(Assoc_Entity : Entity_Id;
Typ : Entity_Id;
Scope : Entity_Id;
Suffix : String) return Entity_Id
is
EF : constant Entity_Id :=
Make_Defining_Identifier (Sloc (Assoc_Entity),
Chars => New_External_Name (Chars (Assoc_Entity),
Suffix => Suffix));
begin
-- A little optimization. Never generate an extra formal for the
-- _init operand of an initialization procedure, since it could
-- never be used.
if Chars (Formal) = Name_uInit then
return Empty;
end if;
Set_Ekind (EF, E_In_Parameter);
Set_Actual_Subtype (EF, Typ);
Set_Etype (EF, Typ);
Set_Scope (EF, Scope);
Set_Mechanism (EF, Default_Mechanism);
Set_Formal_Validity (EF);
if No (First_Extra) then
First_Extra := EF;
Set_Extra_Formals (Scope, First_Extra);
end if;
if Present (Last_Extra) then
Set_Extra_Formal (Last_Extra, EF);
end if;
Last_Extra := EF;
return EF;
end Add_Extra_Formal;
-- Start of processing for Create_Extra_Formals
begin
-- We never generate extra formals if expansion is not active because we
-- don't need them unless we are generating code.
if not Expander_Active then
return;
end if;
-- No need to generate extra formals in interface thunks whose target
-- primitive has no extra formals.
if Is_Thunk (E) and then No (Extra_Formals (Thunk_Entity (E))) then
return;
end if;
-- If this is a derived subprogram then the subtypes of the parent
-- subprogram's formal parameters will be used to determine the need
-- for extra formals.
if Is_Overloadable (E) and then Present (Alias (E)) then
P_Formal := First_Formal (Alias (E));
end if;
Last_Extra := Empty;
Formal := First_Formal (E);
while Present (Formal) loop
Last_Extra := Formal;
Next_Formal (Formal);
end loop;
-- If Extra_formals were already created, don't do it again. This
-- situation may arise for subprogram types created as part of
-- dispatching calls (see Expand_Dispatching_Call)
if Present (Last_Extra) and then Present (Extra_Formal (Last_Extra)) then
return;
end if;
-- If the subprogram is a predefined dispatching subprogram then don't
-- generate any extra constrained or accessibility level formals. In
-- general we suppress these for internal subprograms (by not calling
-- Freeze_Subprogram and Create_Extra_Formals at all), but internally
-- generated stream attributes do get passed through because extra
-- build-in-place formals are needed in some cases (limited 'Input).
if Is_Predefined_Internal_Operation (E) then
goto Test_For_Func_Result_Extras;
end if;
Formal := First_Formal (E);
while Present (Formal) loop
-- Create extra formal for supporting the attribute 'Constrained.
-- The case of a private type view without discriminants also
-- requires the extra formal if the underlying type has defaulted
-- discriminants.
if Ekind (Formal) /= E_In_Parameter then
if Present (P_Formal) then
Formal_Type := Etype (P_Formal);
else
Formal_Type := Etype (Formal);
end if;
-- Do not produce extra formals for Unchecked_Union parameters.
-- Jump directly to the end of the loop.
if Is_Unchecked_Union (Base_Type (Formal_Type)) then
goto Skip_Extra_Formal_Generation;
end if;
if not Has_Discriminants (Formal_Type)
and then Ekind (Formal_Type) in Private_Kind
and then Present (Underlying_Type (Formal_Type))
then
Formal_Type := Underlying_Type (Formal_Type);
end if;
-- Suppress the extra formal if formal's subtype is constrained or
-- indefinite, or we're compiling for Ada 2012 and the underlying
-- type is tagged and limited. In Ada 2012, a limited tagged type
-- can have defaulted discriminants, but 'Constrained is required
-- to return True, so the formal is never needed (see AI05-0214).
-- Note that this ensures consistency of calling sequences for
-- dispatching operations when some types in a class have defaults
-- on discriminants and others do not (and requiring the extra
-- formal would introduce distributed overhead).
-- If the type does not have a completion yet, treat as prior to
-- Ada 2012 for consistency.
if Has_Discriminants (Formal_Type)
and then not Is_Constrained (Formal_Type)
and then not Is_Indefinite_Subtype (Formal_Type)
and then (Ada_Version < Ada_2012
or else No (Underlying_Type (Formal_Type))
or else not
(Is_Limited_Type (Formal_Type)
and then
(Is_Tagged_Type
(Underlying_Type (Formal_Type)))))
then
Set_Extra_Constrained
(Formal, Add_Extra_Formal (Formal, Standard_Boolean, E, "O"));
end if;
end if;
-- Create extra formal for supporting accessibility checking. This
-- is done for both anonymous access formals and formals of named
-- access types that are marked as controlling formals. The latter
-- case can occur when Expand_Dispatching_Call creates a subprogram
-- type and substitutes the types of access-to-class-wide actuals
-- for the anonymous access-to-specific-type of controlling formals.
-- Base_Type is applied because in cases where there is a null
-- exclusion the formal may have an access subtype.
-- This is suppressed if we specifically suppress accessibility
-- checks at the package level for either the subprogram, or the
-- package in which it resides. However, we do not suppress it
-- simply if the scope has accessibility checks suppressed, since
-- this could cause trouble when clients are compiled with a
-- different suppression setting. The explicit checks at the
-- package level are safe from this point of view.
if (Ekind (Base_Type (Etype (Formal))) = E_Anonymous_Access_Type
or else (Is_Controlling_Formal (Formal)
and then Is_Access_Type (Base_Type (Etype (Formal)))))
and then not
(Explicit_Suppress (E, Accessibility_Check)
or else
Explicit_Suppress (Scope (E), Accessibility_Check))
and then
(No (P_Formal)
or else Present (Extra_Accessibility (P_Formal)))
then
Set_Extra_Accessibility
(Formal, Add_Extra_Formal (Formal, Standard_Natural, E, "L"));
end if;
-- This label is required when skipping extra formal generation for
-- Unchecked_Union parameters.
<<Skip_Extra_Formal_Generation>>
if Present (P_Formal) then
Next_Formal (P_Formal);
end if;
Next_Formal (Formal);
end loop;
<<Test_For_Func_Result_Extras>>
-- Ada 2012 (AI05-234): "the accessibility level of the result of a
-- function call is ... determined by the point of call ...".
if Needs_Result_Accessibility_Level (E) then
Set_Extra_Accessibility_Of_Result
(E, Add_Extra_Formal (E, Standard_Natural, E, "L"));
end if;
-- Ada 2005 (AI-318-02): In the case of build-in-place functions, add
-- appropriate extra formals. See type Exp_Ch6.BIP_Formal_Kind.
if Ada_Version >= Ada_2005 and then Is_Build_In_Place_Function (E) then
declare
Result_Subt : constant Entity_Id := Etype (E);
Full_Subt : constant Entity_Id := Available_View (Result_Subt);
Formal_Typ : Entity_Id;
Discard : Entity_Id;
pragma Warnings (Off, Discard);
begin
-- In the case of functions with unconstrained result subtypes,
-- add a 4-state formal indicating whether the return object is
-- allocated by the caller (1), or should be allocated by the
-- callee on the secondary stack (2), in the global heap (3), or
-- in a user-defined storage pool (4). For the moment we just use
-- Natural for the type of this formal. Note that this formal
-- isn't usually needed in the case where the result subtype is
-- constrained, but it is needed when the function has a tagged
-- result, because generally such functions can be called in a
-- dispatching context and such calls must be handled like calls
-- to a class-wide function.
if Needs_BIP_Alloc_Form (E) then
Discard :=
Add_Extra_Formal
(E, Standard_Natural,
E, BIP_Formal_Suffix (BIP_Alloc_Form));
-- Add BIP_Storage_Pool, in case BIP_Alloc_Form indicates to
-- use a user-defined pool. This formal is not added on
-- .NET/JVM/ZFP as those targets do not support pools.
if VM_Target = No_VM
and then RTE_Available (RE_Root_Storage_Pool_Ptr)
then
Discard :=
Add_Extra_Formal
(E, RTE (RE_Root_Storage_Pool_Ptr),
E, BIP_Formal_Suffix (BIP_Storage_Pool));
end if;
end if;
-- In the case of functions whose result type needs finalization,
-- add an extra formal which represents the finalization master.
if Needs_BIP_Finalization_Master (E) then
Discard :=
Add_Extra_Formal
(E, RTE (RE_Finalization_Master_Ptr),
E, BIP_Formal_Suffix (BIP_Finalization_Master));
end if;
-- When the result type contains tasks, add two extra formals: the
-- master of the tasks to be created, and the caller's activation
-- chain.
if Has_Task (Full_Subt) then
Discard :=
Add_Extra_Formal
(E, RTE (RE_Master_Id),
E, BIP_Formal_Suffix (BIP_Task_Master));
Discard :=
Add_Extra_Formal
(E, RTE (RE_Activation_Chain_Access),
E, BIP_Formal_Suffix (BIP_Activation_Chain));
end if;
-- All build-in-place functions get an extra formal that will be
-- passed the address of the return object within the caller.
Formal_Typ :=
Create_Itype (E_Anonymous_Access_Type, E, Scope_Id => Scope (E));
Set_Directly_Designated_Type (Formal_Typ, Result_Subt);
Set_Etype (Formal_Typ, Formal_Typ);
Set_Depends_On_Private
(Formal_Typ, Has_Private_Component (Formal_Typ));
Set_Is_Public (Formal_Typ, Is_Public (Scope (Formal_Typ)));
Set_Is_Access_Constant (Formal_Typ, False);
-- Ada 2005 (AI-50217): Propagate the attribute that indicates
-- the designated type comes from the limited view (for back-end
-- purposes).
Set_From_With_Type (Formal_Typ, From_With_Type (Result_Subt));
Layout_Type (Formal_Typ);
Discard :=
Add_Extra_Formal
(E, Formal_Typ, E, BIP_Formal_Suffix (BIP_Object_Access));
end;
end if;
end Create_Extra_Formals;
-----------------------------
-- Enter_Overloaded_Entity --
-----------------------------
procedure Enter_Overloaded_Entity (S : Entity_Id) is
E : Entity_Id := Current_Entity_In_Scope (S);
C_E : Entity_Id := Current_Entity (S);
begin
if Present (E) then
Set_Has_Homonym (E);
Set_Has_Homonym (S);
end if;
Set_Is_Immediately_Visible (S);
Set_Scope (S, Current_Scope);
-- Chain new entity if front of homonym in current scope, so that
-- homonyms are contiguous.
if Present (E) and then E /= C_E then
while Homonym (C_E) /= E loop
C_E := Homonym (C_E);
end loop;
Set_Homonym (C_E, S);
else
E := C_E;
Set_Current_Entity (S);
end if;
Set_Homonym (S, E);
if Is_Inherited_Operation (S) then
Append_Inherited_Subprogram (S);
else
Append_Entity (S, Current_Scope);
end if;
Set_Public_Status (S);
if Debug_Flag_E then
Write_Str ("New overloaded entity chain: ");
Write_Name (Chars (S));
E := S;
while Present (E) loop
Write_Str (" "); Write_Int (Int (E));
E := Homonym (E);
end loop;
Write_Eol;
end if;
-- Generate warning for hiding
if Warn_On_Hiding
and then Comes_From_Source (S)
and then In_Extended_Main_Source_Unit (S)
then
E := S;
loop
E := Homonym (E);
exit when No (E);
-- Warn unless genuine overloading. Do not emit warning on
-- hiding predefined operators in Standard (these are either an
-- (artifact of our implicit declarations, or simple noise) but
-- keep warning on a operator defined on a local subtype, because
-- of the real danger that different operators may be applied in
-- various parts of the program.
-- Note that if E and S have the same scope, there is never any
-- hiding. Either the two conflict, and the program is illegal,
-- or S is overriding an implicit inherited subprogram.
if Scope (E) /= Scope (S)
and then (not Is_Overloadable (E)
or else Subtype_Conformant (E, S))
and then (Is_Immediately_Visible (E)
or else
Is_Potentially_Use_Visible (S))
then
if Scope (E) /= Standard_Standard then
Error_Msg_Sloc := Sloc (E);
Error_Msg_N ("declaration of & hides one#?h?", S);
elsif Nkind (S) = N_Defining_Operator_Symbol
and then
Scope (Base_Type (Etype (First_Formal (S)))) /= Scope (S)
then
Error_Msg_N
("declaration of & hides predefined operator?h?", S);
end if;
end if;
end loop;
end if;
end Enter_Overloaded_Entity;
-----------------------------
-- Check_Untagged_Equality --
-----------------------------
procedure Check_Untagged_Equality (Eq_Op : Entity_Id) is
Typ : constant Entity_Id := Etype (First_Formal (Eq_Op));
Decl : constant Node_Id := Unit_Declaration_Node (Eq_Op);
Obj_Decl : Node_Id;
begin
if Nkind (Decl) = N_Subprogram_Declaration
and then Is_Record_Type (Typ)
and then not Is_Tagged_Type (Typ)
then
-- If the type is not declared in a package, or if we are in the
-- body of the package or in some other scope, the new operation is
-- not primitive, and therefore legal, though suspicious. If the
-- type is a generic actual (sub)type, the operation is not primitive
-- either because the base type is declared elsewhere.
if Is_Frozen (Typ) then
if Ekind (Scope (Typ)) /= E_Package
or else Scope (Typ) /= Current_Scope
then
null;
elsif Is_Generic_Actual_Type (Typ) then
null;
elsif In_Package_Body (Scope (Typ)) then
Error_Msg_NE
("equality operator must be declared "
& "before type& is frozen", Eq_Op, Typ);
Error_Msg_N
("\move declaration to package spec", Eq_Op);
else
Error_Msg_NE
("equality operator must be declared "
& "before type& is frozen", Eq_Op, Typ);
Obj_Decl := Next (Parent (Typ));
while Present (Obj_Decl) and then Obj_Decl /= Decl loop
if Nkind (Obj_Decl) = N_Object_Declaration
and then Etype (Defining_Identifier (Obj_Decl)) = Typ
then
Error_Msg_NE
("type& is frozen by declaration??", Obj_Decl, Typ);
Error_Msg_N
("\an equality operator cannot be declared after this "
& "point (RM 4.5.2 (9.8)) (Ada 2012))??", Obj_Decl);
exit;
end if;
Next (Obj_Decl);
end loop;
end if;
elsif not In_Same_List (Parent (Typ), Decl)
and then not Is_Limited_Type (Typ)
then
-- This makes it illegal to have a primitive equality declared in
-- the private part if the type is visible.
Error_Msg_N ("equality operator appears too late", Eq_Op);
end if;
end if;
end Check_Untagged_Equality;
-----------------------------
-- Find_Corresponding_Spec --
-----------------------------
function Find_Corresponding_Spec
(N : Node_Id;
Post_Error : Boolean := True) return Entity_Id
is
Spec : constant Node_Id := Specification (N);
Designator : constant Entity_Id := Defining_Entity (Spec);
E : Entity_Id;
function Different_Generic_Profile (E : Entity_Id) return Boolean;
-- Even if fully conformant, a body may depend on a generic actual when
-- the spec does not, or vice versa, in which case they were distinct
-- entities in the generic.
-------------------------------
-- Different_Generic_Profile --
-------------------------------
function Different_Generic_Profile (E : Entity_Id) return Boolean is
F1, F2 : Entity_Id;
function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean;
-- Check that the types of corresponding formals have the same
-- generic actual if any. We have to account for subtypes of a
-- generic formal, declared between a spec and a body, which may
-- appear distinct in an instance but matched in the generic.
-------------------------
-- Same_Generic_Actual --
-------------------------
function Same_Generic_Actual (T1, T2 : Entity_Id) return Boolean is
begin
return Is_Generic_Actual_Type (T1) = Is_Generic_Actual_Type (T2)
or else
(Present (Parent (T1))
and then Comes_From_Source (Parent (T1))
and then Nkind (Parent (T1)) = N_Subtype_Declaration
and then Is_Entity_Name (Subtype_Indication (Parent (T1)))
and then Entity (Subtype_Indication (Parent (T1))) = T2);
end Same_Generic_Actual;
-- Start of processing for Different_Generic_Profile
begin
if not In_Instance then
return False;
elsif Ekind (E) = E_Function
and then not Same_Generic_Actual (Etype (E), Etype (Designator))
then
return True;
end if;
F1 := First_Formal (Designator);
F2 := First_Formal (E);
while Present (F1) loop
if not Same_Generic_Actual (Etype (F1), Etype (F2)) then
return True;
end if;
Next_Formal (F1);
Next_Formal (F2);
end loop;
return False;
end Different_Generic_Profile;
-- Start of processing for Find_Corresponding_Spec
begin
E := Current_Entity (Designator);
while Present (E) loop
-- We are looking for a matching spec. It must have the same scope,
-- and the same name, and either be type conformant, or be the case
-- of a library procedure spec and its body (which belong to one
-- another regardless of whether they are type conformant or not).
if Scope (E) = Current_Scope then
if Current_Scope = Standard_Standard
or else (Ekind (E) = Ekind (Designator)
and then Type_Conformant (E, Designator))
then
-- Within an instantiation, we know that spec and body are
-- subtype conformant, because they were subtype conformant in
-- the generic. We choose the subtype-conformant entity here as
-- well, to resolve spurious ambiguities in the instance that
-- were not present in the generic (i.e. when two different
-- types are given the same actual). If we are looking for a
-- spec to match a body, full conformance is expected.
if In_Instance then
Set_Convention (Designator, Convention (E));
-- Skip past subprogram bodies and subprogram renamings that
-- may appear to have a matching spec, but that aren't fully
-- conformant with it. That can occur in cases where an
-- actual type causes unrelated homographs in the instance.
if Nkind_In (N, N_Subprogram_Body,
N_Subprogram_Renaming_Declaration)
and then Present (Homonym (E))
and then not Fully_Conformant (Designator, E)
then
goto Next_Entity;
elsif not Subtype_Conformant (Designator, E) then
goto Next_Entity;
elsif Different_Generic_Profile (E) then
goto Next_Entity;
end if;
end if;
-- Ada 2012 (AI05-0165): For internally generated bodies of
-- null procedures locate the internally generated spec. We
-- enforce mode conformance since a tagged type may inherit
-- from interfaces several null primitives which differ only
-- in the mode of the formals.
if not (Comes_From_Source (E))
and then Is_Null_Procedure (E)
and then not Mode_Conformant (Designator, E)
then
null;
-- For null procedures coming from source that are completions,
-- analysis of the generated body will establish the link.
elsif Comes_From_Source (E)
and then Nkind (Spec) = N_Procedure_Specification
and then Null_Present (Spec)
then
return E;
elsif not Has_Completion (E) then
if Nkind (N) /= N_Subprogram_Body_Stub then
Set_Corresponding_Spec (N, E);
end if;
Set_Has_Completion (E);
return E;
elsif Nkind (Parent (N)) = N_Subunit then
-- If this is the proper body of a subunit, the completion
-- flag is set when analyzing the stub.
return E;
-- If E is an internal function with a controlling result that
-- was created for an operation inherited by a null extension,
-- it may be overridden by a body without a previous spec (one
-- more reason why these should be shunned). In that case we
-- remove the generated body if present, because the current
-- one is the explicit overriding.
elsif Ekind (E) = E_Function
and then Ada_Version >= Ada_2005
and then not Comes_From_Source (E)
and then Has_Controlling_Result (E)
and then Is_Null_Extension (Etype (E))
and then Comes_From_Source (Spec)
then
Set_Has_Completion (E, False);
if Expander_Active
and then Nkind (Parent (E)) = N_Function_Specification
then
Remove
(Unit_Declaration_Node
(Corresponding_Body (Unit_Declaration_Node (E))));
return E;
-- If expansion is disabled, or if the wrapper function has
-- not been generated yet, this a late body overriding an
-- inherited operation, or it is an overriding by some other
-- declaration before the controlling result is frozen. In
-- either case this is a declaration of a new entity.
else
return Empty;
end if;
-- If the body already exists, then this is an error unless
-- the previous declaration is the implicit declaration of a
-- derived subprogram. It is also legal for an instance to
-- contain type conformant overloadable declarations (but the
-- generic declaration may not), per 8.3(26/2).
elsif No (Alias (E))
and then not Is_Intrinsic_Subprogram (E)
and then not In_Instance
and then Post_Error
then
Error_Msg_Sloc := Sloc (E);
if Is_Imported (E) then
Error_Msg_NE
("body not allowed for imported subprogram & declared#",
N, E);
else
Error_Msg_NE ("duplicate body for & declared#", N, E);
end if;
end if;
-- Child units cannot be overloaded, so a conformance mismatch
-- between body and a previous spec is an error.
elsif Is_Child_Unit (E)
and then
Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
and then
Nkind (Parent (Unit_Declaration_Node (Designator))) =
N_Compilation_Unit
and then Post_Error
then
Error_Msg_N
("body of child unit does not match previous declaration", N);
end if;
end if;
<<Next_Entity>>
E := Homonym (E);
end loop;
-- On exit, we know that no previous declaration of subprogram exists
return Empty;
end Find_Corresponding_Spec;
----------------------
-- Fully_Conformant --
----------------------
function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
return Result;
end Fully_Conformant;
----------------------------------
-- Fully_Conformant_Expressions --
----------------------------------
function Fully_Conformant_Expressions
(Given_E1 : Node_Id;
Given_E2 : Node_Id) return Boolean
is
E1 : constant Node_Id := Original_Node (Given_E1);
E2 : constant Node_Id := Original_Node (Given_E2);
-- We always test conformance on original nodes, since it is possible
-- for analysis and/or expansion to make things look as though they
-- conform when they do not, e.g. by converting 1+2 into 3.
function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
renames Fully_Conformant_Expressions;
function FCL (L1, L2 : List_Id) return Boolean;
-- Compare elements of two lists for conformance. Elements have to be
-- conformant, and actuals inserted as default parameters do not match
-- explicit actuals with the same value.
function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
-- Compare an operator node with a function call
---------
-- FCL --
---------
function FCL (L1, L2 : List_Id) return Boolean is
N1, N2 : Node_Id;
begin
if L1 = No_List then
N1 := Empty;
else
N1 := First (L1);
end if;
if L2 = No_List then
N2 := Empty;
else
N2 := First (L2);
end if;
-- Compare two lists, skipping rewrite insertions (we want to compare
-- the original trees, not the expanded versions!)
loop
if Is_Rewrite_Insertion (N1) then
Next (N1);
elsif Is_Rewrite_Insertion (N2) then
Next (N2);
elsif No (N1) then
return No (N2);
elsif No (N2) then
return False;
elsif not FCE (N1, N2) then
return False;
else
Next (N1);
Next (N2);
end if;
end loop;
end FCL;
---------
-- FCO --
---------
function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
Actuals : constant List_Id := Parameter_Associations (Call_Node);
Act : Node_Id;
begin
if No (Actuals)
or else Entity (Op_Node) /= Entity (Name (Call_Node))
then
return False;
else
Act := First (Actuals);
if Nkind (Op_Node) in N_Binary_Op then
if not FCE (Left_Opnd (Op_Node), Act) then
return False;
end if;
Next (Act);
end if;
return Present (Act)
and then FCE (Right_Opnd (Op_Node), Act)
and then No (Next (Act));
end if;
end FCO;
-- Start of processing for Fully_Conformant_Expressions
begin
-- Non-conformant if paren count does not match. Note: if some idiot
-- complains that we don't do this right for more than 3 levels of
-- parentheses, they will be treated with the respect they deserve!
if Paren_Count (E1) /= Paren_Count (E2) then
return False;
-- If same entities are referenced, then they are conformant even if
-- they have different forms (RM 8.3.1(19-20)).
elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
if Present (Entity (E1)) then
return Entity (E1) = Entity (E2)
or else (Chars (Entity (E1)) = Chars (Entity (E2))
and then Ekind (Entity (E1)) = E_Discriminant
and then Ekind (Entity (E2)) = E_In_Parameter);
elsif Nkind (E1) = N_Expanded_Name
and then Nkind (E2) = N_Expanded_Name
and then Nkind (Selector_Name (E1)) = N_Character_Literal
and then Nkind (Selector_Name (E2)) = N_Character_Literal
then
return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
else
-- Identifiers in component associations don't always have
-- entities, but their names must conform.
return Nkind (E1) = N_Identifier
and then Nkind (E2) = N_Identifier
and then Chars (E1) = Chars (E2);
end if;
elsif Nkind (E1) = N_Character_Literal
and then Nkind (E2) = N_Expanded_Name
then
return Nkind (Selector_Name (E2)) = N_Character_Literal
and then Chars (E1) = Chars (Selector_Name (E2));
elsif Nkind (E2) = N_Character_Literal
and then Nkind (E1) = N_Expanded_Name
then
return Nkind (Selector_Name (E1)) = N_Character_Literal
and then Chars (E2) = Chars (Selector_Name (E1));
elsif Nkind (E1) in N_Op and then Nkind (E2) = N_Function_Call then
return FCO (E1, E2);
elsif Nkind (E2) in N_Op and then Nkind (E1) = N_Function_Call then
return FCO (E2, E1);
-- Otherwise we must have the same syntactic entity
elsif Nkind (E1) /= Nkind (E2) then
return False;
-- At this point, we specialize by node type
else
case Nkind (E1) is
when N_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then
FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Allocator =>
if Nkind (Expression (E1)) = N_Qualified_Expression
or else
Nkind (Expression (E2)) = N_Qualified_Expression
then
return FCE (Expression (E1), Expression (E2));
-- Check that the subtype marks and any constraints
-- are conformant
else
declare
Indic1 : constant Node_Id := Expression (E1);
Indic2 : constant Node_Id := Expression (E2);
Elt1 : Node_Id;
Elt2 : Node_Id;
begin
if Nkind (Indic1) /= N_Subtype_Indication then
return
Nkind (Indic2) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
elsif Nkind (Indic2) /= N_Subtype_Indication then
return
Nkind (Indic1) /= N_Subtype_Indication
and then Entity (Indic1) = Entity (Indic2);
else
if Entity (Subtype_Mark (Indic1)) /=
Entity (Subtype_Mark (Indic2))
then
return False;
end if;
Elt1 := First (Constraints (Constraint (Indic1)));
Elt2 := First (Constraints (Constraint (Indic2)));
while Present (Elt1) and then Present (Elt2) loop
if not FCE (Elt1, Elt2) then
return False;
end if;
Next (Elt1);
Next (Elt2);
end loop;
return True;
end if;
end;
end if;
when N_Attribute_Reference =>
return
Attribute_Name (E1) = Attribute_Name (E2)
and then FCL (Expressions (E1), Expressions (E2));
when N_Binary_Op =>
return
Entity (E1) = Entity (E2)
and then FCE (Left_Opnd (E1), Left_Opnd (E2))
and then FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Short_Circuit | N_Membership_Test =>
return
FCE (Left_Opnd (E1), Left_Opnd (E2))
and then
FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Case_Expression =>
declare
Alt1 : Node_Id;
Alt2 : Node_Id;
begin
if not FCE (Expression (E1), Expression (E2)) then
return False;
else
Alt1 := First (Alternatives (E1));
Alt2 := First (Alternatives (E2));
loop
if Present (Alt1) /= Present (Alt2) then
return False;
elsif No (Alt1) then
return True;
end if;
if not FCE (Expression (Alt1), Expression (Alt2))
or else not FCL (Discrete_Choices (Alt1),
Discrete_Choices (Alt2))
then
return False;
end if;
Next (Alt1);
Next (Alt2);
end loop;
end if;
end;
when N_Character_Literal =>
return
Char_Literal_Value (E1) = Char_Literal_Value (E2);
when N_Component_Association =>
return
FCL (Choices (E1), Choices (E2))
and then
FCE (Expression (E1), Expression (E2));
when N_Explicit_Dereference =>
return
FCE (Prefix (E1), Prefix (E2));
when N_Extension_Aggregate =>
return
FCL (Expressions (E1), Expressions (E2))
and then Null_Record_Present (E1) =
Null_Record_Present (E2)
and then FCL (Component_Associations (E1),
Component_Associations (E2));
when N_Function_Call =>
return
FCE (Name (E1), Name (E2))
and then
FCL (Parameter_Associations (E1),
Parameter_Associations (E2));
when N_If_Expression =>
return
FCL (Expressions (E1), Expressions (E2));
when N_Indexed_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCL (Expressions (E1), Expressions (E2));
when N_Integer_Literal =>
return (Intval (E1) = Intval (E2));
when N_Null =>
return True;
when N_Operator_Symbol =>
return
Chars (E1) = Chars (E2);
when N_Others_Choice =>
return True;
when N_Parameter_Association =>
return
Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
and then FCE (Explicit_Actual_Parameter (E1),
Explicit_Actual_Parameter (E2));
when N_Qualified_Expression =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then
FCE (Expression (E1), Expression (E2));
when N_Quantified_Expression =>
if not FCE (Condition (E1), Condition (E2)) then
return False;
end if;
if Present (Loop_Parameter_Specification (E1))
and then Present (Loop_Parameter_Specification (E2))
then
declare
L1 : constant Node_Id :=
Loop_Parameter_Specification (E1);
L2 : constant Node_Id :=
Loop_Parameter_Specification (E2);
begin
return
Reverse_Present (L1) = Reverse_Present (L2)
and then
FCE (Defining_Identifier (L1),
Defining_Identifier (L2))
and then
FCE (Discrete_Subtype_Definition (L1),
Discrete_Subtype_Definition (L2));
end;
elsif Present (Iterator_Specification (E1))
and then Present (Iterator_Specification (E2))
then
declare
I1 : constant Node_Id := Iterator_Specification (E1);
I2 : constant Node_Id := Iterator_Specification (E2);
begin
return
FCE (Defining_Identifier (I1),
Defining_Identifier (I2))
and then
Of_Present (I1) = Of_Present (I2)
and then
Reverse_Present (I1) = Reverse_Present (I2)
and then FCE (Name (I1), Name (I2))
and then FCE (Subtype_Indication (I1),
Subtype_Indication (I2));
end;
-- The quantified expressions used different specifications to
-- walk their respective ranges.
else
return False;
end if;
when N_Range =>
return
FCE (Low_Bound (E1), Low_Bound (E2))
and then
FCE (High_Bound (E1), High_Bound (E2));
when N_Real_Literal =>
return (Realval (E1) = Realval (E2));
when N_Selected_Component =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCE (Selector_Name (E1), Selector_Name (E2));
when N_Slice =>
return
FCE (Prefix (E1), Prefix (E2))
and then
FCE (Discrete_Range (E1), Discrete_Range (E2));
when N_String_Literal =>
declare
S1 : constant String_Id := Strval (E1);
S2 : constant String_Id := Strval (E2);
L1 : constant Nat := String_Length (S1);
L2 : constant Nat := String_Length (S2);
begin
if L1 /= L2 then
return False;
else
for J in 1 .. L1 loop
if Get_String_Char (S1, J) /=
Get_String_Char (S2, J)
then
return False;
end if;
end loop;
return True;
end if;
end;
when N_Type_Conversion =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then
FCE (Expression (E1), Expression (E2));
when N_Unary_Op =>
return
Entity (E1) = Entity (E2)
and then
FCE (Right_Opnd (E1), Right_Opnd (E2));
when N_Unchecked_Type_Conversion =>
return
FCE (Subtype_Mark (E1), Subtype_Mark (E2))
and then
FCE (Expression (E1), Expression (E2));
-- All other node types cannot appear in this context. Strictly
-- we should raise a fatal internal error. Instead we just ignore
-- the nodes. This means that if anyone makes a mistake in the
-- expander and mucks an expression tree irretrievably, the result
-- will be a failure to detect a (probably very obscure) case
-- of non-conformance, which is better than bombing on some
-- case where two expressions do in fact conform.
when others =>
return True;
end case;
end if;
end Fully_Conformant_Expressions;
----------------------------------------
-- Fully_Conformant_Discrete_Subtypes --
----------------------------------------
function Fully_Conformant_Discrete_Subtypes
(Given_S1 : Node_Id;
Given_S2 : Node_Id) return Boolean
is
S1 : constant Node_Id := Original_Node (Given_S1);
S2 : constant Node_Id := Original_Node (Given_S2);
function Conforming_Bounds (B1, B2 : Node_Id) return Boolean;
-- Special-case for a bound given by a discriminant, which in the body
-- is replaced with the discriminal of the enclosing type.
function Conforming_Ranges (R1, R2 : Node_Id) return Boolean;
-- Check both bounds
-----------------------
-- Conforming_Bounds --
-----------------------
function Conforming_Bounds (B1, B2 : Node_Id) return Boolean is
begin
if Is_Entity_Name (B1)
and then Is_Entity_Name (B2)
and then Ekind (Entity (B1)) = E_Discriminant
then
return Chars (B1) = Chars (B2);
else
return Fully_Conformant_Expressions (B1, B2);
end if;
end Conforming_Bounds;
-----------------------
-- Conforming_Ranges --
-----------------------
function Conforming_Ranges (R1, R2 : Node_Id) return Boolean is
begin
return
Conforming_Bounds (Low_Bound (R1), Low_Bound (R2))
and then
Conforming_Bounds (High_Bound (R1), High_Bound (R2));
end Conforming_Ranges;
-- Start of processing for Fully_Conformant_Discrete_Subtypes
begin
if Nkind (S1) /= Nkind (S2) then
return False;
elsif Is_Entity_Name (S1) then
return Entity (S1) = Entity (S2);
elsif Nkind (S1) = N_Range then
return Conforming_Ranges (S1, S2);
elsif Nkind (S1) = N_Subtype_Indication then
return
Entity (Subtype_Mark (S1)) = Entity (Subtype_Mark (S2))
and then
Conforming_Ranges
(Range_Expression (Constraint (S1)),
Range_Expression (Constraint (S2)));
else
return True;
end if;
end Fully_Conformant_Discrete_Subtypes;
--------------------
-- Install_Entity --
--------------------
procedure Install_Entity (E : Entity_Id) is
Prev : constant Entity_Id := Current_Entity (E);
begin
Set_Is_Immediately_Visible (E);
Set_Current_Entity (E);
Set_Homonym (E, Prev);
end Install_Entity;
---------------------
-- Install_Formals --
---------------------
procedure Install_Formals (Id : Entity_Id) is
F : Entity_Id;
begin
F := First_Formal (Id);
while Present (F) loop
Install_Entity (F);
Next_Formal (F);
end loop;
end Install_Formals;
-----------------------------
-- Is_Interface_Conformant --
-----------------------------
function Is_Interface_Conformant
(Tagged_Type : Entity_Id;
Iface_Prim : Entity_Id;
Prim : Entity_Id) return Boolean
is
-- The operation may in fact be an inherited (implicit) operation
-- rather than the original interface primitive, so retrieve the
-- ultimate ancestor.
Iface : constant Entity_Id :=
Find_Dispatching_Type (Ultimate_Alias (Iface_Prim));
Typ : constant Entity_Id := Find_Dispatching_Type (Prim);
function Controlling_Formal (Prim : Entity_Id) return Entity_Id;
-- Return the controlling formal of Prim
------------------------
-- Controlling_Formal --
------------------------
function Controlling_Formal (Prim : Entity_Id) return Entity_Id is
E : Entity_Id;
begin
E := First_Entity (Prim);
while Present (E) loop
if Is_Formal (E) and then Is_Controlling_Formal (E) then
return E;
end if;
Next_Entity (E);
end loop;
return Empty;
end Controlling_Formal;
-- Local variables
Iface_Ctrl_F : constant Entity_Id := Controlling_Formal (Iface_Prim);
Prim_Ctrl_F : constant Entity_Id := Controlling_Formal (Prim);
-- Start of processing for Is_Interface_Conformant
begin
pragma Assert (Is_Subprogram (Iface_Prim)
and then Is_Subprogram (Prim)
and then Is_Dispatching_Operation (Iface_Prim)
and then Is_Dispatching_Operation (Prim));
pragma Assert (Is_Interface (Iface)
or else (Present (Alias (Iface_Prim))
and then
Is_Interface
(Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
if Prim = Iface_Prim
or else not Is_Subprogram (Prim)
or else Ekind (Prim) /= Ekind (Iface_Prim)
or else not Is_Dispatching_Operation (Prim)
or else Scope (Prim) /= Scope (Tagged_Type)
or else No (Typ)
or else Base_Type (Typ) /= Base_Type (Tagged_Type)
or else not Primitive_Names_Match (Iface_Prim, Prim)
then
return False;
-- The mode of the controlling formals must match
elsif Present (Iface_Ctrl_F)
and then Present (Prim_Ctrl_F)
and then Ekind (Iface_Ctrl_F) /= Ekind (Prim_Ctrl_F)
then
return False;
-- Case of a procedure, or a function whose result type matches the
-- result type of the interface primitive, or a function that has no
-- controlling result (I or access I).
elsif Ekind (Iface_Prim) = E_Procedure
or else Etype (Prim) = Etype (Iface_Prim)
or else not Has_Controlling_Result (Prim)
then
return Type_Conformant
(Iface_Prim, Prim, Skip_Controlling_Formals => True);
-- Case of a function returning an interface, or an access to one. Check
-- that the return types correspond.
elsif Implements_Interface (Typ, Iface) then
if (Ekind (Etype (Prim)) = E_Anonymous_Access_Type)
/=
(Ekind (Etype (Iface_Prim)) = E_Anonymous_Access_Type)
then
return False;
else
return
Type_Conformant (Prim, Ultimate_Alias (Iface_Prim),
Skip_Controlling_Formals => True);
end if;
else
return False;
end if;
end Is_Interface_Conformant;
---------------------------------
-- Is_Non_Overriding_Operation --
---------------------------------
function Is_Non_Overriding_Operation
(Prev_E : Entity_Id;
New_E : Entity_Id) return Boolean
is
Formal : Entity_Id;
F_Typ : Entity_Id;
G_Typ : Entity_Id := Empty;
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
-- If F_Type is a derived type associated with a generic actual subtype,
-- then return its Generic_Parent_Type attribute, else return Empty.
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id) return Boolean;
-- Returns true if and only if the types (or designated types in the
-- case of anonymous access types) are the same or N_Type is derived
-- directly or indirectly from P_Type.
-----------------------------
-- Get_Generic_Parent_Type --
-----------------------------
function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
G_Typ : Entity_Id;
Defn : Node_Id;
Indic : Node_Id;
begin
if Is_Derived_Type (F_Typ)
and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
then
-- The tree must be traversed to determine the parent subtype in
-- the generic unit, which unfortunately isn't always available
-- via semantic attributes. ??? (Note: The use of Original_Node
-- is needed for cases where a full derived type has been
-- rewritten.)
Defn := Type_Definition (Original_Node (Parent (F_Typ)));
if Nkind (Defn) = N_Derived_Type_Definition then
Indic := Subtype_Indication (Defn);
if Nkind (Indic) = N_Subtype_Indication then
G_Typ := Entity (Subtype_Mark (Indic));
else
G_Typ := Entity (Indic);
end if;
if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
and then Present (Generic_Parent_Type (Parent (G_Typ)))
then
return Generic_Parent_Type (Parent (G_Typ));
end if;
end if;
end if;
return Empty;
end Get_Generic_Parent_Type;
----------------------
-- Types_Correspond --
----------------------
function Types_Correspond
(P_Type : Entity_Id;
N_Type : Entity_Id) return Boolean
is
Prev_Type : Entity_Id := Base_Type (P_Type);
New_Type : Entity_Id := Base_Type (N_Type);
begin
if Ekind (Prev_Type) = E_Anonymous_Access_Type then
Prev_Type := Designated_Type (Prev_Type);
end if;
if Ekind (New_Type) = E_Anonymous_Access_Type then
New_Type := Designated_Type (New_Type);
end if;
if Prev_Type = New_Type then
return True;
elsif not Is_Class_Wide_Type (New_Type) then
while Etype (New_Type) /= New_Type loop
New_Type := Etype (New_Type);
if New_Type = Prev_Type then
return True;
end if;
end loop;
end if;
return False;
end Types_Correspond;
-- Start of processing for Is_Non_Overriding_Operation
begin
-- In the case where both operations are implicit derived subprograms
-- then neither overrides the other. This can only occur in certain
-- obscure cases (e.g., derivation from homographs created in a generic
-- instantiation).
if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
return True;
elsif Ekind (Current_Scope) = E_Package
and then Is_Generic_Instance (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Comes_From_Source (New_E)
then
-- We examine the formals and result type of the inherited operation,
-- to determine whether their type is derived from (the instance of)
-- a generic type. The first such formal or result type is the one
-- tested.
Formal := First_Formal (Prev_E);
while Present (Formal) loop
F_Typ := Base_Type (Etype (Formal));
if Ekind (F_Typ) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (F_Typ);
end if;
G_Typ := Get_Generic_Parent_Type (F_Typ);
exit when Present (G_Typ);
Next_Formal (Formal);
end loop;
if No (G_Typ) and then Ekind (Prev_E) = E_Function then
G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
end if;
if No (G_Typ) then
return False;
end if;
-- If the generic type is a private type, then the original operation
-- was not overriding in the generic, because there was no primitive
-- operation to override.
if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
N_Formal_Private_Type_Definition
then
return True;
-- The generic parent type is the ancestor of a formal derived
-- type declaration. We need to check whether it has a primitive
-- operation that should be overridden by New_E in the generic.
else
declare
P_Formal : Entity_Id;
N_Formal : Entity_Id;
P_Typ : Entity_Id;
N_Typ : Entity_Id;
P_Prim : Entity_Id;
Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
begin
while Present (Prim_Elt) loop
P_Prim := Node (Prim_Elt);
if Chars (P_Prim) = Chars (New_E)
and then Ekind (P_Prim) = Ekind (New_E)
then
P_Formal := First_Formal (P_Prim);
N_Formal := First_Formal (New_E);
while Present (P_Formal) and then Present (N_Formal) loop
P_Typ := Etype (P_Formal);
N_Typ := Etype (N_Formal);
if not Types_Correspond (P_Typ, N_Typ) then
exit;
end if;
Next_Entity (P_Formal);
Next_Entity (N_Formal);
end loop;
-- Found a matching primitive operation belonging to the
-- formal ancestor type, so the new subprogram is
-- overriding.
if No (P_Formal)
and then No (N_Formal)
and then (Ekind (New_E) /= E_Function
or else
Types_Correspond
(Etype (P_Prim), Etype (New_E)))
then
return False;
end if;
end if;
Next_Elmt (Prim_Elt);
end loop;
-- If no match found, then the new subprogram does not override
-- in the generic (nor in the instance).
-- If the type in question is not abstract, and the subprogram
-- is, this will be an error if the new operation is in the
-- private part of the instance. Emit a warning now, which will
-- make the subsequent error message easier to understand.
if not Is_Abstract_Type (F_Typ)
and then Is_Abstract_Subprogram (Prev_E)
and then In_Private_Part (Current_Scope)
then
Error_Msg_Node_2 := F_Typ;
Error_Msg_NE
("private operation& in generic unit does not override " &
"any primitive operation of& (RM 12.3 (18))??",
New_E, New_E);
end if;
return True;
end;
end if;
else
return False;
end if;
end Is_Non_Overriding_Operation;
-------------------------------------
-- List_Inherited_Pre_Post_Aspects --
-------------------------------------
procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id) is
begin
if Opt.List_Inherited_Aspects
and then (Is_Subprogram (E) or else Is_Generic_Subprogram (E))
then
declare
Inherited : constant Subprogram_List := Inherited_Subprograms (E);
P : Node_Id;
begin
for J in Inherited'Range loop
P := Pre_Post_Conditions (Contract (Inherited (J)));
while Present (P) loop
Error_Msg_Sloc := Sloc (P);
if Class_Present (P) and then not Split_PPC (P) then
if Pragma_Name (P) = Name_Precondition then
Error_Msg_N
("info: & inherits `Pre''Class` aspect from #?L?",
E);
else
Error_Msg_N
("info: & inherits `Post''Class` aspect from #?L?",
E);
end if;
end if;
P := Next_Pragma (P);
end loop;
end loop;
end;
end if;
end List_Inherited_Pre_Post_Aspects;
------------------------------
-- Make_Inequality_Operator --
------------------------------
-- S is the defining identifier of an equality operator. We build a
-- subprogram declaration with the right signature. This operation is
-- intrinsic, because it is always expanded as the negation of the
-- call to the equality function.
procedure Make_Inequality_Operator (S : Entity_Id) is
Loc : constant Source_Ptr := Sloc (S);
Decl : Node_Id;
Formals : List_Id;
Op_Name : Entity_Id;
FF : constant Entity_Id := First_Formal (S);
NF : constant Entity_Id := Next_Formal (FF);
begin
-- Check that equality was properly defined, ignore call if not
if No (NF) then
return;
end if;
declare
A : constant Entity_Id :=
Make_Defining_Identifier (Sloc (FF),
Chars => Chars (FF));
B : constant Entity_Id :=
Make_Defining_Identifier (Sloc (NF),
Chars => Chars (NF));
begin
Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
Formals := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => A,
Parameter_Type =>
New_Reference_To (Etype (First_Formal (S)),
Sloc (Etype (First_Formal (S))))),
Make_Parameter_Specification (Loc,
Defining_Identifier => B,
Parameter_Type =>
New_Reference_To (Etype (Next_Formal (First_Formal (S))),
Sloc (Etype (Next_Formal (First_Formal (S)))))));
Decl :=
Make_Subprogram_Declaration (Loc,
Specification =>
Make_Function_Specification (Loc,
Defining_Unit_Name => Op_Name,
Parameter_Specifications => Formals,
Result_Definition =>
New_Reference_To (Standard_Boolean, Loc)));
-- Insert inequality right after equality if it is explicit or after
-- the derived type when implicit. These entities are created only
-- for visibility purposes, and eventually replaced in the course
-- of expansion, so they do not need to be attached to the tree and
-- seen by the back-end. Keeping them internal also avoids spurious
-- freezing problems. The declaration is inserted in the tree for
-- analysis, and removed afterwards. If the equality operator comes
-- from an explicit declaration, attach the inequality immediately
-- after. Else the equality is inherited from a derived type
-- declaration, so insert inequality after that declaration.
if No (Alias (S)) then
Insert_After (Unit_Declaration_Node (S), Decl);
elsif Is_List_Member (Parent (S)) then
Insert_After (Parent (S), Decl);
else
Insert_After (Parent (Etype (First_Formal (S))), Decl);
end if;
Mark_Rewrite_Insertion (Decl);
Set_Is_Intrinsic_Subprogram (Op_Name);
Analyze (Decl);
Remove (Decl);
Set_Has_Completion (Op_Name);
Set_Corresponding_Equality (Op_Name, S);
Set_Is_Abstract_Subprogram (Op_Name, Is_Abstract_Subprogram (S));
end;
end Make_Inequality_Operator;
----------------------
-- May_Need_Actuals --
----------------------
procedure May_Need_Actuals (Fun : Entity_Id) is
F : Entity_Id;
B : Boolean;
begin
F := First_Formal (Fun);
B := True;
while Present (F) loop
if No (Default_Value (F)) then
B := False;
exit;
end if;
Next_Formal (F);
end loop;
Set_Needs_No_Actuals (Fun, B);
end May_Need_Actuals;
---------------------
-- Mode_Conformant --
---------------------
function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
return Result;
end Mode_Conformant;
---------------------------
-- New_Overloaded_Entity --
---------------------------
procedure New_Overloaded_Entity
(S : Entity_Id;
Derived_Type : Entity_Id := Empty)
is
Overridden_Subp : Entity_Id := Empty;
-- Set if the current scope has an operation that is type-conformant
-- with S, and becomes hidden by S.
Is_Primitive_Subp : Boolean;
-- Set to True if the new subprogram is primitive
E : Entity_Id;
-- Entity that S overrides
Prev_Vis : Entity_Id := Empty;
-- Predecessor of E in Homonym chain
procedure Check_For_Primitive_Subprogram
(Is_Primitive : out Boolean;
Is_Overriding : Boolean := False);
-- If the subprogram being analyzed is a primitive operation of the type
-- of a formal or result, set the Has_Primitive_Operations flag on the
-- type, and set Is_Primitive to True (otherwise set to False). Set the
-- corresponding flag on the entity itself for later use.
procedure Check_Synchronized_Overriding
(Def_Id : Entity_Id;
Overridden_Subp : out Entity_Id);
-- First determine if Def_Id is an entry or a subprogram either defined
-- in the scope of a task or protected type, or is a primitive of such
-- a type. Check whether Def_Id overrides a subprogram of an interface
-- implemented by the synchronized type, return the overridden entity
-- or Empty.
function Is_Private_Declaration (E : Entity_Id) return Boolean;
-- Check that E is declared in the private part of the current package,
-- or in the package body, where it may hide a previous declaration.
-- We can't use In_Private_Part by itself because this flag is also
-- set when freezing entities, so we must examine the place of the
-- declaration in the tree, and recognize wrapper packages as well.
function Is_Overriding_Alias
(Old_E : Entity_Id;
New_E : Entity_Id) return Boolean;
-- Check whether new subprogram and old subprogram are both inherited
-- from subprograms that have distinct dispatch table entries. This can
-- occur with derivations from instances with accidental homonyms. The
-- function is conservative given that the converse is only true within
-- instances that contain accidental overloadings.
------------------------------------
-- Check_For_Primitive_Subprogram --
------------------------------------
procedure Check_For_Primitive_Subprogram
(Is_Primitive : out Boolean;
Is_Overriding : Boolean := False)
is
Formal : Entity_Id;
F_Typ : Entity_Id;
B_Typ : Entity_Id;
function Visible_Part_Type (T : Entity_Id) return Boolean;
-- Returns true if T is declared in the visible part of the current
-- package scope; otherwise returns false. Assumes that T is declared
-- in a package.
procedure Check_Private_Overriding (T : Entity_Id);
-- Checks that if a primitive abstract subprogram of a visible
-- abstract type is declared in a private part, then it must override
-- an abstract subprogram declared in the visible part. Also checks
-- that if a primitive function with a controlling result is declared
-- in a private part, then it must override a function declared in
-- the visible part.
------------------------------
-- Check_Private_Overriding --
------------------------------
procedure Check_Private_Overriding (T : Entity_Id) is
begin
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Visible_Part_Type (T)
and then not In_Instance
then
if Is_Abstract_Type (T)
and then Is_Abstract_Subprogram (S)
and then (not Is_Overriding
or else not Is_Abstract_Subprogram (E))
then
Error_Msg_N
("abstract subprograms must be visible "
& "(RM 3.9.3(10))!", S);
elsif Ekind (S) = E_Function and then not Is_Overriding then
if Is_Tagged_Type (T) and then T = Base_Type (Etype (S)) then
Error_Msg_N
("private function with tagged result must"
& " override visible-part function", S);
Error_Msg_N
("\move subprogram to the visible part"
& " (RM 3.9.3(10))", S);
-- AI05-0073: extend this test to the case of a function
-- with a controlling access result.
elsif Ekind (Etype (S)) = E_Anonymous_Access_Type
and then Is_Tagged_Type (Designated_Type (Etype (S)))
and then
not Is_Class_Wide_Type (Designated_Type (Etype (S)))
and then Ada_Version >= Ada_2012
then
Error_Msg_N
("private function with controlling access result "
& "must override visible-part function", S);
Error_Msg_N
("\move subprogram to the visible part"
& " (RM 3.9.3(10))", S);
end if;
end if;
end if;
end Check_Private_Overriding;
-----------------------
-- Visible_Part_Type --
-----------------------
function Visible_Part_Type (T : Entity_Id) return Boolean is
P : constant Node_Id := Unit_Declaration_Node (Scope (T));
N : Node_Id;
begin
-- If the entity is a private type, then it must be declared in a
-- visible part.
if Ekind (T) in Private_Kind then
return True;
end if;
-- Otherwise, we traverse the visible part looking for its
-- corresponding declaration. We cannot use the declaration
-- node directly because in the private part the entity of a
-- private type is the one in the full view, which does not
-- indicate that it is the completion of something visible.
N := First (Visible_Declarations (Specification (P)));
while Present (N) loop
if Nkind (N) = N_Full_Type_Declaration
and then Present (Defining_Identifier (N))
and then T = Defining_Identifier (N)
then
return True;
elsif Nkind_In (N, N_Private_Type_Declaration,
N_Private_Extension_Declaration)
and then Present (Defining_Identifier (N))
and then T = Full_View (Defining_Identifier (N))
then
return True;
end if;
Next (N);
end loop;
return False;
end Visible_Part_Type;
-- Start of processing for Check_For_Primitive_Subprogram
begin
Is_Primitive := False;
if not Comes_From_Source (S) then
null;
-- If subprogram is at library level, it is not primitive operation
elsif Current_Scope = Standard_Standard then
null;
elsif (Is_Package_Or_Generic_Package (Current_Scope)
and then not In_Package_Body (Current_Scope))
or else Is_Overriding
then
-- For function, check return type
if Ekind (S) = E_Function then
if Ekind (Etype (S)) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (Etype (S));
else
F_Typ := Etype (S);
end if;
B_Typ := Base_Type (F_Typ);
if Scope (B_Typ) = Current_Scope
and then not Is_Class_Wide_Type (B_Typ)
and then not Is_Generic_Type (B_Typ)
then
Is_Primitive := True;
Set_Has_Primitive_Operations (B_Typ);
Set_Is_Primitive (S);
Check_Private_Overriding (B_Typ);
end if;
end if;
-- For all subprograms, check formals
Formal := First_Formal (S);
while Present (Formal) loop
if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
F_Typ := Designated_Type (Etype (Formal));
else
F_Typ := Etype (Formal);
end if;
B_Typ := Base_Type (F_Typ);
if Ekind (B_Typ) = E_Access_Subtype then
B_Typ := Base_Type (B_Typ);
end if;
if Scope (B_Typ) = Current_Scope
and then not Is_Class_Wide_Type (B_Typ)
and then not Is_Generic_Type (B_Typ)
then
Is_Primitive := True;
Set_Is_Primitive (S);
Set_Has_Primitive_Operations (B_Typ);
Check_Private_Overriding (B_Typ);
end if;
Next_Formal (Formal);
end loop;
-- Special case: An equality function can be redefined for a type
-- occurring in a declarative part, and won't otherwise be treated as
-- a primitive because it doesn't occur in a package spec and doesn't
-- override an inherited subprogram. It's important that we mark it
-- primitive so it can be returned by Collect_Primitive_Operations
-- and be used in composing the equality operation of later types
-- that have a component of the type.
elsif Chars (S) = Name_Op_Eq
and then Etype (S) = Standard_Boolean
then
B_Typ := Base_Type (Etype (First_Formal (S)));
if Scope (B_Typ) = Current_Scope
and then
Base_Type (Etype (Next_Formal (First_Formal (S)))) = B_Typ
and then not Is_Limited_Type (B_Typ)
then
Is_Primitive := True;
Set_Is_Primitive (S);
Set_Has_Primitive_Operations (B_Typ);
Check_Private_Overriding (B_Typ);
end if;
end if;
end Check_For_Primitive_Subprogram;
-----------------------------------
-- Check_Synchronized_Overriding --
-----------------------------------
procedure Check_Synchronized_Overriding
(Def_Id : Entity_Id;
Overridden_Subp : out Entity_Id)
is
Ifaces_List : Elist_Id;
In_Scope : Boolean;
Typ : Entity_Id;
function Matches_Prefixed_View_Profile
(Prim_Params : List_Id;
Iface_Params : List_Id) return Boolean;
-- Determine whether a subprogram's parameter profile Prim_Params
-- matches that of a potentially overridden interface subprogram
-- Iface_Params. Also determine if the type of first parameter of
-- Iface_Params is an implemented interface.
-----------------------------------
-- Matches_Prefixed_View_Profile --
-----------------------------------
function Matches_Prefixed_View_Profile
(Prim_Params : List_Id;
Iface_Params : List_Id) return Boolean
is
Iface_Id : Entity_Id;
Iface_Param : Node_Id;
Iface_Typ : Entity_Id;
Prim_Id : Entity_Id;
Prim_Param : Node_Id;
Prim_Typ : Entity_Id;
function Is_Implemented
(Ifaces_List : Elist_Id;
Iface : Entity_Id) return Boolean;
-- Determine if Iface is implemented by the current task or
-- protected type.
--------------------
-- Is_Implemented --
--------------------
function Is_Implemented
(Ifaces_List : Elist_Id;
Iface : Entity_Id) return Boolean
is
Iface_Elmt : Elmt_Id;
begin
Iface_Elmt := First_Elmt (Ifaces_List);
while Present (Iface_Elmt) loop
if Node (Iface_Elmt) = Iface then
return True;
end if;
Next_Elmt (Iface_Elmt);
end loop;
return False;
end Is_Implemented;
-- Start of processing for Matches_Prefixed_View_Profile
begin
Iface_Param := First (Iface_Params);
Iface_Typ := Etype (Defining_Identifier (Iface_Param));
if Is_Access_Type (Iface_Typ) then
Iface_Typ := Designated_Type (Iface_Typ);
end if;
Prim_Param := First (Prim_Params);
-- The first parameter of the potentially overridden subprogram
-- must be an interface implemented by Prim.
if not Is_Interface (Iface_Typ)
or else not Is_Implemented (Ifaces_List, Iface_Typ)
then
return False;
end if;
-- The checks on the object parameters are done, move onto the
-- rest of the parameters.
if not In_Scope then
Prim_Param := Next (Prim_Param);
end if;
Iface_Param := Next (Iface_Param);
while Present (Iface_Param) and then Present (Prim_Param) loop
Iface_Id := Defining_Identifier (Iface_Param);
Iface_Typ := Find_Parameter_Type (Iface_Param);
Prim_Id := Defining_Identifier (Prim_Param);
Prim_Typ := Find_Parameter_Type (Prim_Param);
if Ekind (Iface_Typ) = E_Anonymous_Access_Type
and then Ekind (Prim_Typ) = E_Anonymous_Access_Type
and then Is_Concurrent_Type (Designated_Type (Prim_Typ))
then
Iface_Typ := Designated_Type (Iface_Typ);
Prim_Typ := Designated_Type (Prim_Typ);
end if;
-- Case of multiple interface types inside a parameter profile
-- (Obj_Param : in out Iface; ...; Param : Iface)
-- If the interface type is implemented, then the matching type
-- in the primitive should be the implementing record type.
if Ekind (Iface_Typ) = E_Record_Type
and then Is_Interface (Iface_Typ)
and then Is_Implemented (Ifaces_List, Iface_Typ)
then
if Prim_Typ /= Typ then
return False;
end if;
-- The two parameters must be both mode and subtype conformant
elsif Ekind (Iface_Id) /= Ekind (Prim_Id)
or else not
Conforming_Types (Iface_Typ, Prim_Typ, Subtype_Conformant)
then
return False;
end if;
Next (Iface_Param);
Next (Prim_Param);
end loop;
-- One of the two lists contains more parameters than the other
if Present (Iface_Param) or else Present (Prim_Param) then
return False;
end if;
return True;
end Matches_Prefixed_View_Profile;
-- Start of processing for Check_Synchronized_Overriding
begin
Overridden_Subp := Empty;
-- Def_Id must be an entry or a subprogram. We should skip predefined
-- primitives internally generated by the frontend; however at this
-- stage predefined primitives are still not fully decorated. As a
-- minor optimization we skip here internally generated subprograms.
if (Ekind (Def_Id) /= E_Entry
and then Ekind (Def_Id) /= E_Function
and then Ekind (Def_Id) /= E_Procedure)
or else not Comes_From_Source (Def_Id)
then
return;
end if;
-- Search for the concurrent declaration since it contains the list
-- of all implemented interfaces. In this case, the subprogram is
-- declared within the scope of a protected or a task type.
if Present (Scope (Def_Id))
and then Is_Concurrent_Type (Scope (Def_Id))
and then not Is_Generic_Actual_Type (Scope (Def_Id))
then
Typ := Scope (Def_Id);
In_Scope := True;
-- The enclosing scope is not a synchronized type and the subprogram
-- has no formals.
elsif No (First_Formal (Def_Id)) then
return;
-- The subprogram has formals and hence it may be a primitive of a
-- concurrent type.
else
Typ := Etype (First_Formal (Def_Id));
if Is_Access_Type (Typ) then
Typ := Directly_Designated_Type (Typ);
end if;
if Is_Concurrent_Type (Typ)
and then not Is_Generic_Actual_Type (Typ)
then
In_Scope := False;
-- This case occurs when the concurrent type is declared within
-- a generic unit. As a result the corresponding record has been
-- built and used as the type of the first formal, we just have
-- to retrieve the corresponding concurrent type.
elsif Is_Concurrent_Record_Type (Typ)
and then not Is_Class_Wide_Type (Typ)
and then Present (Corresponding_Concurrent_Type (Typ))
then
Typ := Corresponding_Concurrent_Type (Typ);
In_Scope := False;
else
return;
end if;
end if;
-- There is no overriding to check if is an inherited operation in a
-- type derivation on for a generic actual.
Collect_Interfaces (Typ, Ifaces_List);
if Is_Empty_Elmt_List (Ifaces_List) then
return;
end if;
-- Determine whether entry or subprogram Def_Id overrides a primitive
-- operation that belongs to one of the interfaces in Ifaces_List.
declare
Candidate : Entity_Id := Empty;
Hom : Entity_Id := Empty;
Iface_Typ : Entity_Id;
Subp : Entity_Id := Empty;
begin
-- Traverse the homonym chain, looking for a potentially
-- overridden subprogram that belongs to an implemented
-- interface.
Hom := Current_Entity_In_Scope (Def_Id);
while Present (Hom) loop
Subp := Hom;
if Subp = Def_Id
or else not Is_Overloadable (Subp)
or else not Is_Primitive (Subp)
or else not Is_Dispatching_Operation (Subp)
or else not Present (Find_Dispatching_Type (Subp))
or else not Is_Interface (Find_Dispatching_Type (Subp))
then
null;
-- Entries and procedures can override abstract or null
-- interface procedures.
elsif (Ekind (Def_Id) = E_Procedure
or else Ekind (Def_Id) = E_Entry)
and then Ekind (Subp) = E_Procedure
and then Matches_Prefixed_View_Profile
(Parameter_Specifications (Parent (Def_Id)),
Parameter_Specifications (Parent (Subp)))
then
Candidate := Subp;
-- For an overridden subprogram Subp, check whether the mode
-- of its first parameter is correct depending on the kind
-- of synchronized type.
declare
Formal : constant Node_Id := First_Formal (Candidate);
begin
-- In order for an entry or a protected procedure to
-- override, the first parameter of the overridden
-- routine must be of mode "out", "in out" or
-- access-to-variable.
if Ekind_In (Candidate, E_Entry, E_Procedure)
and then Is_Protected_Type (Typ)
and then Ekind (Formal) /= E_In_Out_Parameter
and then Ekind (Formal) /= E_Out_Parameter
and then Nkind (Parameter_Type (Parent (Formal))) /=
N_Access_Definition
then
null;
-- All other cases are OK since a task entry or routine
-- does not have a restriction on the mode of the first
-- parameter of the overridden interface routine.
else
Overridden_Subp := Candidate;
return;
end if;
end;
-- Functions can override abstract interface functions
elsif Ekind (Def_Id) = E_Function
and then Ekind (Subp) = E_Function
and then Matches_Prefixed_View_Profile
(Parameter_Specifications (Parent (Def_Id)),
Parameter_Specifications (Parent (Subp)))
and then Etype (Result_Definition (Parent (Def_Id))) =
Etype (Result_Definition (Parent (Subp)))
then
Overridden_Subp := Subp;
return;
end if;
Hom := Homonym (Hom);
end loop;
-- After examining all candidates for overriding, we are left with
-- the best match which is a mode incompatible interface routine.
-- Do not emit an error if the Expander is active since this error
-- will be detected later on after all concurrent types are
-- expanded and all wrappers are built. This check is meant for
-- spec-only compilations.
if Present (Candidate) and then not Expander_Active then
Iface_Typ :=
Find_Parameter_Type (Parent (First_Formal (Candidate)));
-- Def_Id is primitive of a protected type, declared inside the
-- type, and the candidate is primitive of a limited or
-- synchronized interface.
if In_Scope
and then Is_Protected_Type (Typ)
and then
(Is_Limited_Interface (Iface_Typ)
or else Is_Protected_Interface (Iface_Typ)
or else Is_Synchronized_Interface (Iface_Typ)
or else Is_Task_Interface (Iface_Typ))
then
Error_Msg_PT (Parent (Typ), Candidate);
end if;
end if;
Overridden_Subp := Candidate;
return;
end;
end Check_Synchronized_Overriding;
----------------------------
-- Is_Private_Declaration --
----------------------------
function Is_Private_Declaration (E : Entity_Id) return Boolean is
Priv_Decls : List_Id;
Decl : constant Node_Id := Unit_Declaration_Node (E);
begin
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Priv_Decls :=
Private_Declarations
(Specification (Unit_Declaration_Node (Current_Scope)));
return In_Package_Body (Current_Scope)
or else
(Is_List_Member (Decl)
and then List_Containing (Decl) = Priv_Decls)
or else (Nkind (Parent (Decl)) = N_Package_Specification
and then not
Is_Compilation_Unit
(Defining_Entity (Parent (Decl)))
and then List_Containing (Parent (Parent (Decl))) =
Priv_Decls);
else
return False;
end if;
end Is_Private_Declaration;
--------------------------
-- Is_Overriding_Alias --
--------------------------
function Is_Overriding_Alias
(Old_E : Entity_Id;
New_E : Entity_Id) return Boolean
is
AO : constant Entity_Id := Alias (Old_E);
AN : constant Entity_Id := Alias (New_E);
begin
return Scope (AO) /= Scope (AN)
or else No (DTC_Entity (AO))
or else No (DTC_Entity (AN))
or else DT_Position (AO) = DT_Position (AN);
end Is_Overriding_Alias;
-- Start of processing for New_Overloaded_Entity
begin
-- We need to look for an entity that S may override. This must be a
-- homonym in the current scope, so we look for the first homonym of
-- S in the current scope as the starting point for the search.
E := Current_Entity_In_Scope (S);
-- Ada 2005 (AI-251): Derivation of abstract interface primitives.
-- They are directly added to the list of primitive operations of
-- Derived_Type, unless this is a rederivation in the private part
-- of an operation that was already derived in the visible part of
-- the current package.
if Ada_Version >= Ada_2005
and then Present (Derived_Type)
and then Present (Alias (S))
and then Is_Dispatching_Operation (Alias (S))
and then Present (Find_Dispatching_Type (Alias (S)))
and then Is_Interface (Find_Dispatching_Type (Alias (S)))
then
-- For private types, when the full-view is processed we propagate to
-- the full view the non-overridden entities whose attribute "alias"
-- references an interface primitive. These entities were added by
-- Derive_Subprograms to ensure that interface primitives are
-- covered.
-- Inside_Freeze_Actions is non zero when S corresponds with an
-- internal entity that links an interface primitive with its
-- covering primitive through attribute Interface_Alias (see
-- Add_Internal_Interface_Entities).
if Inside_Freezing_Actions = 0
and then Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
and then Nkind (Parent (E)) = N_Private_Extension_Declaration
and then Nkind (Parent (S)) = N_Full_Type_Declaration
and then Full_View (Defining_Identifier (Parent (E)))
= Defining_Identifier (Parent (S))
and then Alias (E) = Alias (S)
then
Check_Operation_From_Private_View (S, E);
Set_Is_Dispatching_Operation (S);
-- Common case
else
Enter_Overloaded_Entity (S);
Check_Dispatching_Operation (S, Empty);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
end if;
return;
end if;
-- If there is no homonym then this is definitely not overriding
if No (E) then
Enter_Overloaded_Entity (S);
Check_Dispatching_Operation (S, Empty);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
-- If subprogram has an explicit declaration, check whether it has an
-- overriding indicator.
if Comes_From_Source (S) then
Check_Synchronized_Overriding (S, Overridden_Subp);
-- (Ada 2012: AI05-0125-1): If S is a dispatching operation then
-- it may have overridden some hidden inherited primitive. Update
-- Overridden_Subp to avoid spurious errors when checking the
-- overriding indicator.
if Ada_Version >= Ada_2012
and then No (Overridden_Subp)
and then Is_Dispatching_Operation (S)
and then Present (Overridden_Operation (S))
then
Overridden_Subp := Overridden_Operation (S);
end if;
Check_Overriding_Indicator
(S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
end if;
-- If there is a homonym that is not overloadable, then we have an
-- error, except for the special cases checked explicitly below.
elsif not Is_Overloadable (E) then
-- Check for spurious conflict produced by a subprogram that has the
-- same name as that of the enclosing generic package. The conflict
-- occurs within an instance, between the subprogram and the renaming
-- declaration for the package. After the subprogram, the package
-- renaming declaration becomes hidden.
if Ekind (E) = E_Package
and then Present (Renamed_Object (E))
and then Renamed_Object (E) = Current_Scope
and then Nkind (Parent (Renamed_Object (E))) =
N_Package_Specification
and then Present (Generic_Parent (Parent (Renamed_Object (E))))
then
Set_Is_Hidden (E);
Set_Is_Immediately_Visible (E, False);
Enter_Overloaded_Entity (S);
Set_Homonym (S, Homonym (E));
Check_Dispatching_Operation (S, Empty);
Check_Overriding_Indicator (S, Empty, Is_Primitive => False);
-- If the subprogram is implicit it is hidden by the previous
-- declaration. However if it is dispatching, it must appear in the
-- dispatch table anyway, because it can be dispatched to even if it
-- cannot be called directly.
elsif Present (Alias (S)) and then not Comes_From_Source (S) then
Set_Scope (S, Current_Scope);
if Is_Dispatching_Operation (Alias (S)) then
Check_Dispatching_Operation (S, Empty);
end if;
return;
else
Error_Msg_Sloc := Sloc (E);
-- Generate message, with useful additional warning if in generic
if Is_Generic_Unit (E) then
Error_Msg_N ("previous generic unit cannot be overloaded", S);
Error_Msg_N ("\& conflicts with declaration#", S);
else
Error_Msg_N ("& conflicts with declaration#", S);
end if;
return;
end if;
-- E exists and is overloadable
else
Check_Synchronized_Overriding (S, Overridden_Subp);
-- Loop through E and its homonyms to determine if any of them is
-- the candidate for overriding by S.
while Present (E) loop
-- Definitely not interesting if not in the current scope
if Scope (E) /= Current_Scope then
null;
-- Ada 2012 (AI05-0165): For internally generated bodies of null
-- procedures locate the internally generated spec. We enforce
-- mode conformance since a tagged type may inherit from
-- interfaces several null primitives which differ only in
-- the mode of the formals.
elsif not Comes_From_Source (S)
and then Is_Null_Procedure (S)
and then not Mode_Conformant (E, S)
then
null;
-- Check if we have type conformance
elsif Type_Conformant (E, S) then
-- If the old and new entities have the same profile and one
-- is not the body of the other, then this is an error, unless
-- one of them is implicitly declared.
-- There are some cases when both can be implicit, for example
-- when both a literal and a function that overrides it are
-- inherited in a derivation, or when an inherited operation
-- of a tagged full type overrides the inherited operation of
-- a private extension. Ada 83 had a special rule for the
-- literal case. In Ada 95, the later implicit operation hides
-- the former, and the literal is always the former. In the
-- odd case where both are derived operations declared at the
-- same point, both operations should be declared, and in that
-- case we bypass the following test and proceed to the next
-- part. This can only occur for certain obscure cases in
-- instances, when an operation on a type derived from a formal
-- private type does not override a homograph inherited from
-- the actual. In subsequent derivations of such a type, the
-- DT positions of these operations remain distinct, if they
-- have been set.
if Present (Alias (S))
and then (No (Alias (E))
or else Comes_From_Source (E)
or else Is_Abstract_Subprogram (S)
or else
(Is_Dispatching_Operation (E)
and then Is_Overriding_Alias (E, S)))
and then Ekind (E) /= E_Enumeration_Literal
then
-- When an derived operation is overloaded it may be due to
-- the fact that the full view of a private extension
-- re-inherits. It has to be dealt with.
if Is_Package_Or_Generic_Package (Current_Scope)
and then In_Private_Part (Current_Scope)
then
Check_Operation_From_Private_View (S, E);
end if;
-- In any case the implicit operation remains hidden by the
-- existing declaration, which is overriding. Indicate that
-- E overrides the operation from which S is inherited.
if Present (Alias (S)) then
Set_Overridden_Operation (E, Alias (S));
else
Set_Overridden_Operation (E, S);
end if;
if Comes_From_Source (E) then
Check_Overriding_Indicator (E, S, Is_Primitive => False);
end if;
return;
-- Within an instance, the renaming declarations for actual
-- subprograms may become ambiguous, but they do not hide each
-- other.
elsif Ekind (E) /= E_Entry
and then not Comes_From_Source (E)
and then not Is_Generic_Instance (E)
and then (Present (Alias (E))
or else Is_Intrinsic_Subprogram (E))
and then (not In_Instance
or else No (Parent (E))
or else Nkind (Unit_Declaration_Node (E)) /=
N_Subprogram_Renaming_Declaration)
then
-- A subprogram child unit is not allowed to override an
-- inherited subprogram (10.1.1(20)).
if Is_Child_Unit (S) then
Error_Msg_N
("child unit overrides inherited subprogram in parent",
S);
return;
end if;
if Is_Non_Overriding_Operation (E, S) then
Enter_Overloaded_Entity (S);
if No (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
return;
end if;
-- E is a derived operation or an internal operator which
-- is being overridden. Remove E from further visibility.
-- Furthermore, if E is a dispatching operation, it must be
-- replaced in the list of primitive operations of its type
-- (see Override_Dispatching_Operation).
Overridden_Subp := E;
declare
Prev : Entity_Id;
begin
Prev := First_Entity (Current_Scope);
while Present (Prev) and then Next_Entity (Prev) /= E loop
Next_Entity (Prev);
end loop;
-- It is possible for E to be in the current scope and
-- yet not in the entity chain. This can only occur in a
-- generic context where E is an implicit concatenation
-- in the formal part, because in a generic body the
-- entity chain starts with the formals.
pragma Assert
(Present (Prev) or else Chars (E) = Name_Op_Concat);
-- E must be removed both from the entity_list of the
-- current scope, and from the visibility chain
if Debug_Flag_E then
Write_Str ("Override implicit operation ");
Write_Int (Int (E));
Write_Eol;
end if;
-- If E is a predefined concatenation, it stands for four
-- different operations. As a result, a single explicit
-- declaration does not hide it. In a possible ambiguous
-- situation, Disambiguate chooses the user-defined op,
-- so it is correct to retain the previous internal one.
if Chars (E) /= Name_Op_Concat
or else Ekind (E) /= E_Operator
then
-- For nondispatching derived operations that are
-- overridden by a subprogram declared in the private
-- part of a package, we retain the derived subprogram
-- but mark it as not immediately visible. If the
-- derived operation was declared in the visible part
-- then this ensures that it will still be visible
-- outside the package with the proper signature
-- (calls from outside must also be directed to this
-- version rather than the overriding one, unlike the
-- dispatching case). Calls from inside the package
-- will still resolve to the overriding subprogram
-- since the derived one is marked as not visible
-- within the package.
-- If the private operation is dispatching, we achieve
-- the overriding by keeping the implicit operation
-- but setting its alias to be the overriding one. In
-- this fashion the proper body is executed in all
-- cases, but the original signature is used outside
-- of the package.
-- If the overriding is not in the private part, we
-- remove the implicit operation altogether.
if Is_Private_Declaration (S) then
if not Is_Dispatching_Operation (E) then
Set_Is_Immediately_Visible (E, False);
else
-- Work done in Override_Dispatching_Operation,
-- so nothing else needs to be done here.
null;
end if;
else
-- Find predecessor of E in Homonym chain
if E = Current_Entity (E) then
Prev_Vis := Empty;
else
Prev_Vis := Current_Entity (E);
while Homonym (Prev_Vis) /= E loop
Prev_Vis := Homonym (Prev_Vis);
end loop;
end if;
if Prev_Vis /= Empty then
-- Skip E in the visibility chain
Set_Homonym (Prev_Vis, Homonym (E));
else
Set_Name_Entity_Id (Chars (E), Homonym (E));
end if;
Set_Next_Entity (Prev, Next_Entity (E));
if No (Next_Entity (Prev)) then
Set_Last_Entity (Current_Scope, Prev);
end if;
end if;
end if;
Enter_Overloaded_Entity (S);
-- For entities generated by Derive_Subprograms the
-- overridden operation is the inherited primitive
-- (which is available through the attribute alias).
if not (Comes_From_Source (E))
and then Is_Dispatching_Operation (E)
and then Find_Dispatching_Type (E) =
Find_Dispatching_Type (S)
and then Present (Alias (E))
and then Comes_From_Source (Alias (E))
then
Set_Overridden_Operation (S, Alias (E));
-- Normal case of setting entity as overridden
-- Note: Static_Initialization and Overridden_Operation
-- attributes use the same field in subprogram entities.
-- Static_Initialization is only defined for internal
-- initialization procedures, where Overridden_Operation
-- is irrelevant. Therefore the setting of this attribute
-- must check whether the target is an init_proc.
elsif not Is_Init_Proc (S) then
Set_Overridden_Operation (S, E);
end if;
Check_Overriding_Indicator (S, E, Is_Primitive => True);
-- If S is a user-defined subprogram or a null procedure
-- expanded to override an inherited null procedure, or a
-- predefined dispatching primitive then indicate that E
-- overrides the operation from which S is inherited.
if Comes_From_Source (S)
or else
(Present (Parent (S))
and then
Nkind (Parent (S)) = N_Procedure_Specification
and then
Null_Present (Parent (S)))
or else
(Present (Alias (E))
and then
Is_Predefined_Dispatching_Operation (Alias (E)))
then
if Present (Alias (E)) then
Set_Overridden_Operation (S, Alias (E));
end if;
end if;
if Is_Dispatching_Operation (E) then
-- An overriding dispatching subprogram inherits the
-- convention of the overridden subprogram (AI-117).
Set_Convention (S, Convention (E));
Check_Dispatching_Operation (S, E);
else
Check_Dispatching_Operation (S, Empty);
end if;
Check_For_Primitive_Subprogram
(Is_Primitive_Subp, Is_Overriding => True);
goto Check_Inequality;
end;
-- Apparent redeclarations in instances can occur when two
-- formal types get the same actual type. The subprograms in
-- in the instance are legal, even if not callable from the
-- outside. Calls from within are disambiguated elsewhere.
-- For dispatching operations in the visible part, the usual
-- rules apply, and operations with the same profile are not
-- legal (B830001).
elsif (In_Instance_Visible_Part
and then not Is_Dispatching_Operation (E))
or else In_Instance_Not_Visible
then
null;
-- Here we have a real error (identical profile)
else
Error_Msg_Sloc := Sloc (E);
-- Avoid cascaded errors if the entity appears in
-- subsequent calls.
Set_Scope (S, Current_Scope);
-- Generate error, with extra useful warning for the case
-- of a generic instance with no completion.
if Is_Generic_Instance (S)
and then not Has_Completion (E)
then
Error_Msg_N
("instantiation cannot provide body for&", S);
Error_Msg_N ("\& conflicts with declaration#", S);
else
Error_Msg_N ("& conflicts with declaration#", S);
end if;
return;
end if;
else
-- If one subprogram has an access parameter and the other
-- a parameter of an access type, calls to either might be
-- ambiguous. Verify that parameters match except for the
-- access parameter.
if May_Hide_Profile then
declare
F1 : Entity_Id;
F2 : Entity_Id;
begin
F1 := First_Formal (S);
F2 := First_Formal (E);
while Present (F1) and then Present (F2) loop
if Is_Access_Type (Etype (F1)) then
if not Is_Access_Type (Etype (F2))
or else not Conforming_Types
(Designated_Type (Etype (F1)),
Designated_Type (Etype (F2)),
Type_Conformant)
then
May_Hide_Profile := False;
end if;
elsif
not Conforming_Types
(Etype (F1), Etype (F2), Type_Conformant)
then
May_Hide_Profile := False;
end if;
Next_Formal (F1);
Next_Formal (F2);
end loop;
if May_Hide_Profile
and then No (F1)
and then No (F2)
then
Error_Msg_NE ("calls to& may be ambiguous??", S, S);
end if;
end;
end if;
end if;
E := Homonym (E);
end loop;
-- On exit, we know that S is a new entity
Enter_Overloaded_Entity (S);
Check_For_Primitive_Subprogram (Is_Primitive_Subp);
Check_Overriding_Indicator
(S, Overridden_Subp, Is_Primitive => Is_Primitive_Subp);
-- Overloading is not allowed in SPARK, except for operators
if Nkind (S) /= N_Defining_Operator_Symbol then
Error_Msg_Sloc := Sloc (Homonym (S));
Check_SPARK_Restriction
("overloading not allowed with entity#", S);
end if;
-- If S is a derived operation for an untagged type then by
-- definition it's not a dispatching operation (even if the parent
-- operation was dispatching), so Check_Dispatching_Operation is not
-- called in that case.
if No (Derived_Type)
or else Is_Tagged_Type (Derived_Type)
then
Check_Dispatching_Operation (S, Empty);
end if;
end if;
-- If this is a user-defined equality operator that is not a derived
-- subprogram, create the corresponding inequality. If the operation is
-- dispatching, the expansion is done elsewhere, and we do not create
-- an explicit inequality operation.
<<Check_Inequality>>
if Chars (S) = Name_Op_Eq
and then Etype (S) = Standard_Boolean
and then Present (Parent (S))
and then not Is_Dispatching_Operation (S)
then
Make_Inequality_Operator (S);
if Ada_Version >= Ada_2012 then
Check_Untagged_Equality (S);
end if;
end if;
end New_Overloaded_Entity;
---------------------
-- Process_Formals --
---------------------
procedure Process_Formals
(T : List_Id;
Related_Nod : Node_Id)
is
Param_Spec : Node_Id;
Formal : Entity_Id;
Formal_Type : Entity_Id;
Default : Node_Id;
Ptype : Entity_Id;
Num_Out_Params : Nat := 0;
First_Out_Param : Entity_Id := Empty;
-- Used for setting Is_Only_Out_Parameter
function Designates_From_With_Type (Typ : Entity_Id) return Boolean;
-- Determine whether an access type designates a type coming from a
-- limited view.
function Is_Class_Wide_Default (D : Node_Id) return Boolean;
-- Check whether the default has a class-wide type. After analysis the
-- default has the type of the formal, so we must also check explicitly
-- for an access attribute.
-------------------------------
-- Designates_From_With_Type --
-------------------------------
function Designates_From_With_Type (Typ : Entity_Id) return Boolean is
Desig : Entity_Id := Typ;
begin
if Is_Access_Type (Desig) then
Desig := Directly_Designated_Type (Desig);
end if;
if Is_Class_Wide_Type (Desig) then
Desig := Root_Type (Desig);
end if;
return
Ekind (Desig) = E_Incomplete_Type and then From_With_Type (Desig);
end Designates_From_With_Type;
---------------------------
-- Is_Class_Wide_Default --
---------------------------
function Is_Class_Wide_Default (D : Node_Id) return Boolean is
begin
return Is_Class_Wide_Type (Designated_Type (Etype (D)))
or else (Nkind (D) = N_Attribute_Reference
and then Attribute_Name (D) = Name_Access
and then Is_Class_Wide_Type (Etype (Prefix (D))));
end Is_Class_Wide_Default;
-- Start of processing for Process_Formals
begin
-- In order to prevent premature use of the formals in the same formal
-- part, the Ekind is left undefined until all default expressions are
-- analyzed. The Ekind is established in a separate loop at the end.
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Set_Never_Set_In_Source (Formal, True);
Enter_Name (Formal);
-- Case of ordinary parameters
if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
Find_Type (Parameter_Type (Param_Spec));
Ptype := Parameter_Type (Param_Spec);
if Ptype = Error then
goto Continue;
end if;
Formal_Type := Entity (Ptype);
if Is_Incomplete_Type (Formal_Type)
or else
(Is_Class_Wide_Type (Formal_Type)
and then Is_Incomplete_Type (Root_Type (Formal_Type)))
then
-- Ada 2005 (AI-326): Tagged incomplete types allowed in
-- primitive operations, as long as their completion is
-- in the same declarative part. If in the private part
-- this means that the type cannot be a Taft-amendment type.
-- Check is done on package exit. For access to subprograms,
-- the use is legal for Taft-amendment types.
-- Ada 2012: tagged incomplete types are allowed as generic
-- formal types. They do not introduce dependencies and the
-- corresponding generic subprogram does not have a delayed
-- freeze, because it does not need a freeze node.
if Is_Tagged_Type (Formal_Type) then
if Ekind (Scope (Current_Scope)) = E_Package
and then not From_With_Type (Formal_Type)
and then not Is_Generic_Type (Formal_Type)
and then not Is_Class_Wide_Type (Formal_Type)
then
if not Nkind_In
(Parent (T), N_Access_Function_Definition,
N_Access_Procedure_Definition)
then
Append_Elmt
(Current_Scope,
Private_Dependents (Base_Type (Formal_Type)));
-- Freezing is delayed to ensure that Register_Prim
-- will get called for this operation, which is needed
-- in cases where static dispatch tables aren't built.
-- (Note that the same is done for controlling access
-- parameter cases in function Access_Definition.)
Set_Has_Delayed_Freeze (Current_Scope);
end if;
end if;
-- Special handling of Value_Type for CIL case
elsif Is_Value_Type (Formal_Type) then
null;
elsif not Nkind_In (Parent (T), N_Access_Function_Definition,
N_Access_Procedure_Definition)
then
-- AI05-0151: Tagged incomplete types are allowed in all
-- formal parts. Untagged incomplete types are not allowed
-- in bodies.
if Ada_Version >= Ada_2012 then
if Is_Tagged_Type (Formal_Type) then
null;
elsif Nkind_In (Parent (Parent (T)), N_Accept_Statement,
N_Entry_Body,
N_Subprogram_Body)
then
Error_Msg_NE
("invalid use of untagged incomplete type&",
Ptype, Formal_Type);
end if;
else
Error_Msg_NE
("invalid use of incomplete type&",
Param_Spec, Formal_Type);
-- Further checks on the legality of incomplete types
-- in formal parts are delayed until the freeze point
-- of the enclosing subprogram or access to subprogram.
end if;
end if;
elsif Ekind (Formal_Type) = E_Void then
Error_Msg_NE
("premature use of&",
Parameter_Type (Param_Spec), Formal_Type);
end if;
-- Ada 2012 (AI-142): Handle aliased parameters
if Ada_Version >= Ada_2012
and then Aliased_Present (Param_Spec)
then
Set_Is_Aliased (Formal);
end if;
-- Ada 2005 (AI-231): Create and decorate an internal subtype
-- declaration corresponding to the null-excluding type of the
-- formal in the enclosing scope. Finally, replace the parameter
-- type of the formal with the internal subtype.
if Ada_Version >= Ada_2005
and then Null_Exclusion_Present (Param_Spec)
then
if not Is_Access_Type (Formal_Type) then
Error_Msg_N
("`NOT NULL` allowed only for an access type", Param_Spec);
else
if Can_Never_Be_Null (Formal_Type)
and then Comes_From_Source (Related_Nod)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)",
Param_Spec, Formal_Type);
end if;
Formal_Type :=
Create_Null_Excluding_Itype
(T => Formal_Type,
Related_Nod => Related_Nod,
Scope_Id => Scope (Current_Scope));
-- If the designated type of the itype is an itype that is
-- not frozen yet, we set the Has_Delayed_Freeze attribute
-- on the access subtype, to prevent order-of-elaboration
-- issues in the backend.
-- Example:
-- type T is access procedure;
-- procedure Op (O : not null T);
if Is_Itype (Directly_Designated_Type (Formal_Type))
and then
not Is_Frozen (Directly_Designated_Type (Formal_Type))
then
Set_Has_Delayed_Freeze (Formal_Type);
end if;
end if;
end if;
-- An access formal type
else
Formal_Type :=
Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
-- No need to continue if we already notified errors
if not Present (Formal_Type) then
return;
end if;
-- Ada 2005 (AI-254)
declare
AD : constant Node_Id :=
Access_To_Subprogram_Definition
(Parameter_Type (Param_Spec));
begin
if Present (AD) and then Protected_Present (AD) then
Formal_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram
(Param_Spec);
end if;
end;
end if;
Set_Etype (Formal, Formal_Type);
-- Deal with default expression if present
Default := Expression (Param_Spec);
if Present (Default) then
Check_SPARK_Restriction
("default expression is not allowed", Default);
if Out_Present (Param_Spec) then
Error_Msg_N
("default initialization only allowed for IN parameters",
Param_Spec);
end if;
-- Do the special preanalysis of the expression (see section on
-- "Handling of Default Expressions" in the spec of package Sem).
Preanalyze_Spec_Expression (Default, Formal_Type);
-- An access to constant cannot be the default for
-- an access parameter that is an access to variable.
if Ekind (Formal_Type) = E_Anonymous_Access_Type
and then not Is_Access_Constant (Formal_Type)
and then Is_Access_Type (Etype (Default))
and then Is_Access_Constant (Etype (Default))
then
Error_Msg_N
("formal that is access to variable cannot be initialized " &
"with an access-to-constant expression", Default);
end if;
-- Check that the designated type of an access parameter's default
-- is not a class-wide type unless the parameter's designated type
-- is also class-wide.
if Ekind (Formal_Type) = E_Anonymous_Access_Type
and then not Designates_From_With_Type (Formal_Type)
and then Is_Class_Wide_Default (Default)
and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
then
Error_Msg_N
("access to class-wide expression not allowed here", Default);
end if;
-- Check incorrect use of dynamically tagged expressions
if Is_Tagged_Type (Formal_Type) then
Check_Dynamically_Tagged_Expression
(Expr => Default,
Typ => Formal_Type,
Related_Nod => Default);
end if;
end if;
-- Ada 2005 (AI-231): Static checks
if Ada_Version >= Ada_2005
and then Is_Access_Type (Etype (Formal))
and then Can_Never_Be_Null (Etype (Formal))
then
Null_Exclusion_Static_Checks (Param_Spec);
end if;
<<Continue>>
Next (Param_Spec);
end loop;
-- If this is the formal part of a function specification, analyze the
-- subtype mark in the context where the formals are visible but not
-- yet usable, and may hide outer homographs.
if Nkind (Related_Nod) = N_Function_Specification then
Analyze_Return_Type (Related_Nod);
end if;
-- Now set the kind (mode) of each formal
Param_Spec := First (T);
while Present (Param_Spec) loop
Formal := Defining_Identifier (Param_Spec);
Set_Formal_Mode (Formal);
if Ekind (Formal) = E_In_Parameter then
Set_Default_Value (Formal, Expression (Param_Spec));
if Present (Expression (Param_Spec)) then
Default := Expression (Param_Spec);
if Is_Scalar_Type (Etype (Default)) then
if Nkind (Parameter_Type (Param_Spec)) /=
N_Access_Definition
then
Formal_Type := Entity (Parameter_Type (Param_Spec));
else
Formal_Type :=
Access_Definition
(Related_Nod, Parameter_Type (Param_Spec));
end if;
Apply_Scalar_Range_Check (Default, Formal_Type);
end if;
end if;
elsif Ekind (Formal) = E_Out_Parameter then
Num_Out_Params := Num_Out_Params + 1;
if Num_Out_Params = 1 then
First_Out_Param := Formal;
end if;
elsif Ekind (Formal) = E_In_Out_Parameter then
Num_Out_Params := Num_Out_Params + 1;
end if;
-- Skip remaining processing if formal type was in error
if Etype (Formal) = Any_Type or else Error_Posted (Formal) then
goto Next_Parameter;
end if;
-- Force call by reference if aliased
if Is_Aliased (Formal) then
Set_Mechanism (Formal, By_Reference);
-- Warn if user asked this to be passed by copy
if Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then
Error_Msg_N
("cannot pass aliased parameter & by copy?", Formal);
end if;
-- Force mechanism if type has Convention Ada_Pass_By_Ref/Copy
elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Copy then
Set_Mechanism (Formal, By_Copy);
elsif Convention (Formal_Type) = Convention_Ada_Pass_By_Reference then
Set_Mechanism (Formal, By_Reference);
end if;
<<Next_Parameter>>
Next (Param_Spec);
end loop;
if Present (First_Out_Param) and then Num_Out_Params = 1 then
Set_Is_Only_Out_Parameter (First_Out_Param);
end if;
end Process_Formals;
------------------
-- Process_PPCs --
------------------
procedure Process_PPCs
(N : Node_Id;
Spec_Id : Entity_Id;
Body_Id : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Prag : Node_Id;
Parms : List_Id;
Designator : Entity_Id;
-- Subprogram designator, set from Spec_Id if present, else Body_Id
Precond : Node_Id := Empty;
-- Set non-Empty if we prepend precondition to the declarations. This
-- is used to hook up inherited preconditions (adding the condition
-- expression with OR ELSE, and adding the message).
Inherited_Precond : Node_Id;
-- Precondition inherited from parent subprogram
Inherited : constant Subprogram_List :=
Inherited_Subprograms (Spec_Id);
-- List of subprograms inherited by this subprogram
Plist : List_Id := No_List;
-- List of generated postconditions
procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id);
-- Append a node to a list. If there is no list, create a new one. When
-- the item denotes a pragma, it is added to the list only when it is
-- enabled.
procedure Check_Access_Invariants (E : Entity_Id);
-- If the subprogram returns an access to a type with invariants, or
-- has access parameters whose designated type has an invariant, then
-- under the same visibility conditions as for other invariant checks,
-- the type invariant must be applied to the returned value.
function Grab_PPC (Pspec : Entity_Id := Empty) return Node_Id;
-- Prag contains an analyzed precondition or postcondition pragma. This
-- function copies the pragma, changes it to the corresponding Check
-- pragma and returns the Check pragma as the result. If Pspec is non-
-- empty, this is the case of inheriting a PPC, where we must change
-- references to parameters of the inherited subprogram to point to the
-- corresponding parameters of the current subprogram.
function Has_Checked_Predicate (Typ : Entity_Id) return Boolean;
-- Determine whether type Typ has or inherits at least one predicate
-- aspect or pragma, for which the applicable policy is Checked.
function Has_Null_Body (Proc_Id : Entity_Id) return Boolean;
-- Determine whether the body of procedure Proc_Id contains a sole null
-- statement, possibly followed by an optional return.
procedure Insert_After_Last_Declaration (Nod : Node_Id);
-- Insert node Nod after the last declaration of the context
function Is_Public_Subprogram_For (T : Entity_Id) return Boolean;
-- T is the entity for a private type for which invariants are defined.
-- This function returns True if the procedure corresponding to the
-- value of Designator is a public procedure from the point of view of
-- this type (i.e. its spec is in the visible part of the package that
-- contains the declaration of the private type). A True value means
-- that an invariant check is required (for an IN OUT parameter, or
-- the returned value of a function.
-------------------------
-- Append_Enabled_Item --
-------------------------
procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id) is
begin
-- Do not chain ignored or disabled pragmas
if Nkind (Item) = N_Pragma
and then (Is_Ignored (Item) or else Is_Disabled (Item))
then
null;
-- Add the item
else
if No (List) then
List := New_List;
end if;
Append (Item, List);
end if;
end Append_Enabled_Item;
-----------------------------
-- Check_Access_Invariants --
-----------------------------
procedure Check_Access_Invariants (E : Entity_Id) is
Call : Node_Id;
Obj : Node_Id;
Typ : Entity_Id;
begin
if Is_Access_Type (Etype (E))
and then not Is_Access_Constant (Etype (E))
then
Typ := Designated_Type (Etype (E));
if Has_Invariants (Typ)
and then Present (Invariant_Procedure (Typ))
and then not Has_Null_Body (Invariant_Procedure (Typ))
and then Is_Public_Subprogram_For (Typ)
then
Obj :=
Make_Explicit_Dereference (Loc,
Prefix => New_Occurrence_Of (E, Loc));
Set_Etype (Obj, Typ);
Call := Make_Invariant_Call (Obj);
Append_Enabled_Item
(Make_If_Statement (Loc,
Condition =>
Make_Op_Ne (Loc,
Left_Opnd => Make_Null (Loc),
Right_Opnd => New_Occurrence_Of (E, Loc)),
Then_Statements => New_List (Call)),
List => Plist);
end if;
end if;
end Check_Access_Invariants;
--------------
-- Grab_PPC --
--------------
function Grab_PPC (Pspec : Entity_Id := Empty) return Node_Id is
Nam : constant Name_Id := Pragma_Name (Prag);
Map : Elist_Id;
CP : Node_Id;
Ename : Name_Id;
-- Effective name of pragma (maybe Pre/Post rather than Precondition/
-- Postcodition if the pragma came from a Pre/Post aspect). We need
-- the name right when we generate the Check pragma, since we want
-- the right set of check policies to apply.
begin
-- Prepare map if this is the case where we have to map entities of
-- arguments in the overridden subprogram to corresponding entities
-- of the current subprogram.
if No (Pspec) then
Map := No_Elist;
else
declare
PF : Entity_Id;
CF : Entity_Id;
begin
Map := New_Elmt_List;
PF := First_Formal (Pspec);
CF := First_Formal (Designator);
while Present (PF) loop
Append_Elmt (PF, Map);
Append_Elmt (CF, Map);
Next_Formal (PF);
Next_Formal (CF);
end loop;
end;
end if;
-- Now we can copy the tree, doing any required substitutions
CP := New_Copy_Tree (Prag, Map => Map, New_Scope => Current_Scope);
-- Set Analyzed to false, since we want to reanalyze the check
-- procedure. Note that it is only at the outer level that we
-- do this fiddling, for the spec cases, the already preanalyzed
-- parameters are not affected.
Set_Analyzed (CP, False);
-- We also make sure Comes_From_Source is False for the copy
Set_Comes_From_Source (CP, False);
-- For a postcondition pragma within a generic, preserve the pragma
-- for later expansion. This is also used when an error was detected,
-- thus setting Expander_Active to False.
if Nam = Name_Postcondition
and then not Expander_Active
then
return CP;
end if;
-- Get effective name of aspect
if Present (Corresponding_Aspect (Prag)) then
Ename := Chars (Identifier (Corresponding_Aspect (Prag)));
else
Ename := Nam;
end if;
-- Change copy of pragma into corresponding pragma Check
Prepend_To (Pragma_Argument_Associations (CP),
Make_Pragma_Argument_Association (Sloc (Prag),
Expression => Make_Identifier (Loc, Ename)));
Set_Pragma_Identifier (CP, Make_Identifier (Sloc (Prag), Name_Check));
-- If this is inherited case and the current message starts with
-- "failed p", we change it to "failed inherited p...".
if Present (Pspec) then
declare
Msg : constant Node_Id :=
Last (Pragma_Argument_Associations (CP));
begin
if Chars (Msg) = Name_Message then
String_To_Name_Buffer (Strval (Expression (Msg)));
if Name_Buffer (1 .. 8) = "failed p" then
Insert_Str_In_Name_Buffer ("inherited ", 8);
Set_Strval
(Expression (Last (Pragma_Argument_Associations (CP))),
String_From_Name_Buffer);
end if;
end if;
end;
end if;
-- Return the check pragma
return CP;
end Grab_PPC;
---------------------------
-- Has_Checked_Predicate --
---------------------------
function Has_Checked_Predicate (Typ : Entity_Id) return Boolean is
Anc : Entity_Id;
Pred : Node_Id;
begin
-- Climb the ancestor type chain staring from the input. This is done
-- because the input type may lack aspect/pragma predicate and simply
-- inherit those from its ancestor.
-- Note that predicate pragmas include all three cases of predicate
-- aspects (Predicate, Dynamic_Predicate, Static_Predicate), so this
-- routine checks for all three cases.
Anc := Typ;
while Present (Anc) loop
Pred := Get_Pragma (Anc, Pragma_Predicate);
if Present (Pred) and then not Is_Ignored (Pred) then
return True;
end if;
Anc := Nearest_Ancestor (Anc);
end loop;
return False;
end Has_Checked_Predicate;
-------------------
-- Has_Null_Body --
-------------------
function Has_Null_Body (Proc_Id : Entity_Id) return Boolean is
Body_Id : Entity_Id;
Decl : Node_Id;
Spec : Node_Id;
Stmt1 : Node_Id;
Stmt2 : Node_Id;
begin
Spec := Parent (Proc_Id);
Decl := Parent (Spec);
-- Retrieve the entity of the invariant procedure body
if Nkind (Spec) = N_Procedure_Specification
and then Nkind (Decl) = N_Subprogram_Declaration
then
Body_Id := Corresponding_Body (Decl);
-- The body acts as a spec
else
Body_Id := Proc_Id;
end if;
-- The body will be generated later
if No (Body_Id) then
return False;
end if;
Spec := Parent (Body_Id);
Decl := Parent (Spec);
pragma Assert
(Nkind (Spec) = N_Procedure_Specification
and then Nkind (Decl) = N_Subprogram_Body);
Stmt1 := First (Statements (Handled_Statement_Sequence (Decl)));
-- Look for a null statement followed by an optional return statement
if Nkind (Stmt1) = N_Null_Statement then
Stmt2 := Next (Stmt1);
if Present (Stmt2) then
return Nkind (Stmt2) = N_Simple_Return_Statement;
else
return True;
end if;
end if;
return False;
end Has_Null_Body;
-----------------------------------
-- Insert_After_Last_Declaration --
-----------------------------------
procedure Insert_After_Last_Declaration (Nod : Node_Id) is
Decls : constant List_Id := Declarations (N);
begin
if No (Decls) then
Set_Declarations (N, New_List (Nod));
else
Append_To (Decls, Nod);
end if;
end Insert_After_Last_Declaration;
------------------------------
-- Is_Public_Subprogram_For --
------------------------------
-- The type T is a private type, its declaration is therefore in
-- the list of public declarations of some package. The test for a
-- public subprogram is that its declaration is in this same list
-- of declarations for the same package (note that all the public
-- declarations are in one list, and all the private declarations
-- in another, so this deals with the public/private distinction).
function Is_Public_Subprogram_For (T : Entity_Id) return Boolean is
DD : constant Node_Id := Unit_Declaration_Node (Designator);
-- The subprogram declaration for the subprogram in question
TL : constant List_Id :=
Visible_Declarations
(Specification (Unit_Declaration_Node (Scope (T))));
-- The list of declarations containing the private declaration of
-- the type. We know it is a private type, so we know its scope is
-- the package in question, and we know it must be in the visible
-- declarations of this package.
begin
-- If the subprogram declaration is not a list member, it must be
-- an Init_Proc, in which case we want to consider it to be a
-- public subprogram, since we do get initializations to deal with.
-- Other internally generated subprograms are not public.
if not Is_List_Member (DD)
and then Is_Init_Proc (Defining_Entity (DD))
then
return True;
-- The declaration may have been generated for an expression function
-- so check whether that function comes from source.
elsif not Comes_From_Source (DD)
and then
(Nkind (Original_Node (DD)) /= N_Expression_Function
or else not Comes_From_Source (Defining_Entity (DD)))
then
return False;
-- Otherwise we test whether the subprogram is declared in the
-- visible declarations of the package containing the type.
else
return TL = List_Containing (DD);
end if;
end Is_Public_Subprogram_For;
-- Local variables
Formal : Node_Id;
Formal_Typ : Entity_Id;
Func_Typ : Entity_Id;
Post_Proc : Entity_Id;
Result : Node_Id;
-- Start of processing for Process_PPCs
begin
-- Capture designator from spec if present, else from body
if Present (Spec_Id) then
Designator := Spec_Id;
else
Designator := Body_Id;
end if;
-- Do not process a predicate function as its body will contain a
-- recursive call to itself and blow up the stack.
if Ekind (Designator) = E_Function
and then Is_Predicate_Function (Designator)
then
return;
-- Internally generated subprograms, such as type-specific functions,
-- don't get assertion checks.
elsif Get_TSS_Name (Designator) /= TSS_Null then
return;
end if;
-- Grab preconditions from spec
if Present (Spec_Id) then
-- Loop through PPC pragmas from spec. Note that preconditions from
-- the body will be analyzed and converted when we scan the body
-- declarations below.
Prag := Pre_Post_Conditions (Contract (Spec_Id));
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Precondition then
-- For Pre (or Precondition pragma), we simply prepend the
-- pragma to the list of declarations right away so that it
-- will be executed at the start of the procedure. Note that
-- this processing reverses the order of the list, which is
-- what we want since new entries were chained to the head of
-- the list. There can be more than one precondition when we
-- use pragma Precondition.
if not Class_Present (Prag) then
Prepend (Grab_PPC, Declarations (N));
-- For Pre'Class there can only be one pragma, and we save
-- it in Precond for now. We will add inherited Pre'Class
-- stuff before inserting this pragma in the declarations.
else
Precond := Grab_PPC;
end if;
end if;
Prag := Next_Pragma (Prag);
end loop;
-- Now deal with inherited preconditions
for J in Inherited'Range loop
Prag := Pre_Post_Conditions (Contract (Inherited (J)));
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Precondition
and then Class_Present (Prag)
then
Inherited_Precond := Grab_PPC (Inherited (J));
-- No precondition so far, so establish this as the first
if No (Precond) then
Precond := Inherited_Precond;
-- Here we already have a precondition, add inherited one
else
-- Add new precondition to old one using OR ELSE
declare
New_Expr : constant Node_Id :=
Get_Pragma_Arg
(Next (First (Pragma_Argument_Associations
(Inherited_Precond))));
Old_Expr : constant Node_Id :=
Get_Pragma_Arg
(Next (First (Pragma_Argument_Associations
(Precond))));
begin
if Paren_Count (Old_Expr) = 0 then
Set_Paren_Count (Old_Expr, 1);
end if;
if Paren_Count (New_Expr) = 0 then
Set_Paren_Count (New_Expr, 1);
end if;
Rewrite (Old_Expr,
Make_Or_Else (Sloc (Old_Expr),
Left_Opnd => Relocate_Node (Old_Expr),
Right_Opnd => New_Expr));
end;
-- Add new message in the form:
-- failed precondition from bla
-- also failed inherited precondition from bla
-- ...
-- Skip this if exception locations are suppressed
if not Exception_Locations_Suppressed then
declare
New_Msg : constant Node_Id :=
Get_Pragma_Arg
(Last
(Pragma_Argument_Associations
(Inherited_Precond)));
Old_Msg : constant Node_Id :=
Get_Pragma_Arg
(Last
(Pragma_Argument_Associations
(Precond)));
begin
Start_String (Strval (Old_Msg));
Store_String_Chars (ASCII.LF & " also ");
Store_String_Chars (Strval (New_Msg));
Set_Strval (Old_Msg, End_String);
end;
end if;
end if;
end if;
Prag := Next_Pragma (Prag);
end loop;
end loop;
-- If we have built a precondition for Pre'Class (including any
-- Pre'Class aspects inherited from parent subprograms), then we
-- insert this composite precondition at this stage.
if Present (Precond) then
Prepend (Precond, Declarations (N));
end if;
end if;
-- Build postconditions procedure if needed and prepend the following
-- declaration to the start of the declarations for the subprogram.
-- procedure _postconditions [(_Result : resulttype)] is
-- begin
-- pragma Check (Postcondition, condition [,message]);
-- pragma Check (Postcondition, condition [,message]);
-- ...
-- Invariant_Procedure (_Result) ...
-- Invariant_Procedure (Arg1)
-- ...
-- end;
-- First we deal with the postconditions in the body
if Is_Non_Empty_List (Declarations (N)) then
-- Loop through declarations
Prag := First (Declarations (N));
while Present (Prag) loop
if Nkind (Prag) = N_Pragma then
-- Capture postcondition pragmas
if Pragma_Name (Prag) = Name_Postcondition then
Analyze (Prag);
-- If expansion is disabled, as in a generic unit, save
-- pragma for later expansion.
if not Expander_Active then
Prepend (Grab_PPC, Declarations (N));
else
Append_Enabled_Item (Grab_PPC, Plist);
end if;
end if;
Next (Prag);
-- Not a pragma, if comes from source, then end scan
elsif Comes_From_Source (Prag) then
exit;
-- Skip stuff not coming from source
else
Next (Prag);
end if;
end loop;
end if;
-- Now deal with any postconditions from the spec
if Present (Spec_Id) then
Spec_Postconditions : declare
procedure Process_Contract_Cases (Spec : Node_Id);
-- This processes the Contract_Test_Cases from Spec, processing
-- any contract-cases from the list. The caller has checked that
-- Contract_Test_Cases is non-Empty.
procedure Process_Post_Conditions
(Spec : Node_Id;
Class : Boolean);
-- This processes the Pre_Post_Conditions from Spec, processing
-- any postconditions from the list. If Class is True, then only
-- postconditions marked with Class_Present are considered. The
-- caller has checked that Pre_Post_Conditions is non-Empty.
----------------------------
-- Process_Contract_Cases --
----------------------------
procedure Process_Contract_Cases (Spec : Node_Id) is
begin
-- Loop through Contract_Cases pragmas from spec
Prag := Contract_Test_Cases (Contract (Spec));
loop
if Pragma_Name (Prag) = Name_Contract_Cases then
Expand_Contract_Cases
(CCs => Prag,
Subp_Id => Spec_Id,
Decls => Declarations (N),
Stmts => Plist);
end if;
Prag := Next_Pragma (Prag);
exit when No (Prag);
end loop;
end Process_Contract_Cases;
-----------------------------
-- Process_Post_Conditions --
-----------------------------
procedure Process_Post_Conditions
(Spec : Node_Id;
Class : Boolean)
is
Pspec : Node_Id;
begin
if Class then
Pspec := Spec;
else
Pspec := Empty;
end if;
-- Loop through PPC pragmas from spec
Prag := Pre_Post_Conditions (Contract (Spec));
loop
if Pragma_Name (Prag) = Name_Postcondition
and then (not Class or else Class_Present (Prag))
then
if not Expander_Active then
Prepend (Grab_PPC (Pspec), Declarations (N));
else
Append_Enabled_Item (Grab_PPC (Pspec), Plist);
end if;
end if;
Prag := Next_Pragma (Prag);
exit when No (Prag);
end loop;
end Process_Post_Conditions;
-- Start of processing for Spec_Postconditions
begin
-- Process postconditions expressed as contract-cases
if Present (Contract_Test_Cases (Contract (Spec_Id))) then
Process_Contract_Cases (Spec_Id);
end if;
-- Process spec postconditions
if Present (Pre_Post_Conditions (Contract (Spec_Id))) then
Process_Post_Conditions (Spec_Id, Class => False);
end if;
-- Process inherited postconditions
for J in Inherited'Range loop
if Present (Pre_Post_Conditions (Contract (Inherited (J)))) then
Process_Post_Conditions (Inherited (J), Class => True);
end if;
end loop;
end Spec_Postconditions;
end if;
-- Add an invariant call to check the result of a function
if Ekind (Designator) /= E_Procedure and then Expander_Active then
Func_Typ := Etype (Designator);
Result := Make_Defining_Identifier (Loc, Name_uResult);
Set_Etype (Result, Func_Typ);
-- Add argument for return
Parms := New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Result,
Parameter_Type => New_Occurrence_Of (Func_Typ, Loc)));
-- Add invariant call if returning type with invariants and this is a
-- public function, i.e. a function declared in the visible part of
-- the package defining the private type.
if Has_Invariants (Func_Typ)
and then Present (Invariant_Procedure (Func_Typ))
and then not Has_Null_Body (Invariant_Procedure (Func_Typ))
and then Is_Public_Subprogram_For (Func_Typ)
then
Append_Enabled_Item
(Make_Invariant_Call (New_Occurrence_Of (Result, Loc)), Plist);
end if;
-- Same if return value is an access to type with invariants
Check_Access_Invariants (Result);
-- Procedure case
else
Parms := No_List;
end if;
-- Add invariant calls and predicate calls for parameters. Note that
-- this is done for functions as well, since in Ada 2012 they can have
-- IN OUT args.
if Expander_Active then
Formal := First_Formal (Designator);
while Present (Formal) loop
if Ekind (Formal) /= E_In_Parameter
or else Is_Access_Type (Etype (Formal))
then
Formal_Typ := Etype (Formal);
if Has_Invariants (Formal_Typ)
and then Present (Invariant_Procedure (Formal_Typ))
and then not Has_Null_Body (Invariant_Procedure (Formal_Typ))
and then Is_Public_Subprogram_For (Formal_Typ)
then
Append_Enabled_Item
(Make_Invariant_Call (New_Occurrence_Of (Formal, Loc)),
Plist);
end if;
Check_Access_Invariants (Formal);
if Has_Predicates (Formal_Typ)
and then Present (Predicate_Function (Formal_Typ))
and then Has_Checked_Predicate (Formal_Typ)
then
Append_Enabled_Item
(Make_Predicate_Check
(Formal_Typ, New_Occurrence_Of (Formal, Loc)),
Plist);
end if;
end if;
Next_Formal (Formal);
end loop;
end if;
-- Build and insert postcondition procedure
if Expander_Active and then Present (Plist) then
Post_Proc :=
Make_Defining_Identifier (Loc, Chars => Name_uPostconditions);
-- Insert the corresponding body of a post condition pragma after the
-- last declaration of the context. This ensures that the body will
-- not cause any premature freezing as it may mention types:
-- procedure Proc (Obj : Array_Typ) is
-- procedure _postconditions is
-- begin
-- ... Obj ...
-- end _postconditions;
-- subtype T is Array_Typ (Obj'First (1) .. Obj'Last (1));
-- begin
-- In the example above, Obj is of type T but the incorrect placement
-- of _postconditions will cause a crash in gigi due to an out of
-- order reference. The body of _postconditions must be placed after
-- the declaration of Temp to preserve correct visibility.
Insert_After_Last_Declaration (
Make_Subprogram_Body (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Post_Proc,
Parameter_Specifications => Parms),
Declarations => Empty_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Plist)));
Set_Ekind (Post_Proc, E_Procedure);
-- If this is a procedure, set the Postcondition_Proc attribute on
-- the proper defining entity for the subprogram.
if Ekind (Designator) = E_Procedure then
Set_Postcondition_Proc (Designator, Post_Proc);
end if;
Set_Has_Postconditions (Designator);
end if;
end Process_PPCs;
----------------------------
-- Reference_Body_Formals --
----------------------------
procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id) is
Fs : Entity_Id;
Fb : Entity_Id;
begin
if Error_Posted (Spec) then
return;
end if;
-- Iterate over both lists. They may be of different lengths if the two
-- specs are not conformant.
Fs := First_Formal (Spec);
Fb := First_Formal (Bod);
while Present (Fs) and then Present (Fb) loop
Generate_Reference (Fs, Fb, 'b');
if Style_Check then
Style.Check_Identifier (Fb, Fs);
end if;
Set_Spec_Entity (Fb, Fs);
Set_Referenced (Fs, False);
Next_Formal (Fs);
Next_Formal (Fb);
end loop;
end Reference_Body_Formals;
-------------------------
-- Set_Actual_Subtypes --
-------------------------
procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
Decl : Node_Id;
Formal : Entity_Id;
T : Entity_Id;
First_Stmt : Node_Id := Empty;
AS_Needed : Boolean;
begin
-- If this is an empty initialization procedure, no need to create
-- actual subtypes (small optimization).
if Ekind (Subp) = E_Procedure and then Is_Null_Init_Proc (Subp) then
return;
end if;
Formal := First_Formal (Subp);
while Present (Formal) loop
T := Etype (Formal);
-- We never need an actual subtype for a constrained formal
if Is_Constrained (T) then
AS_Needed := False;
-- If we have unknown discriminants, then we do not need an actual
-- subtype, or more accurately we cannot figure it out! Note that
-- all class-wide types have unknown discriminants.
elsif Has_Unknown_Discriminants (T) then
AS_Needed := False;
-- At this stage we have an unconstrained type that may need an
-- actual subtype. For sure the actual subtype is needed if we have
-- an unconstrained array type.
elsif Is_Array_Type (T) then
AS_Needed := True;
-- The only other case needing an actual subtype is an unconstrained
-- record type which is an IN parameter (we cannot generate actual
-- subtypes for the OUT or IN OUT case, since an assignment can
-- change the discriminant values. However we exclude the case of
-- initialization procedures, since discriminants are handled very
-- specially in this context, see the section entitled "Handling of
-- Discriminants" in Einfo.
-- We also exclude the case of Discrim_SO_Functions (functions used
-- in front end layout mode for size/offset values), since in such
-- functions only discriminants are referenced, and not only are such
-- subtypes not needed, but they cannot always be generated, because
-- of order of elaboration issues.
elsif Is_Record_Type (T)
and then Ekind (Formal) = E_In_Parameter
and then Chars (Formal) /= Name_uInit
and then not Is_Unchecked_Union (T)
and then not Is_Discrim_SO_Function (Subp)
then
AS_Needed := True;
-- All other cases do not need an actual subtype
else
AS_Needed := False;
end if;
-- Generate actual subtypes for unconstrained arrays and
-- unconstrained discriminated records.
if AS_Needed then
if Nkind (N) = N_Accept_Statement then
-- If expansion is active, the formal is replaced by a local
-- variable that renames the corresponding entry of the
-- parameter block, and it is this local variable that may
-- require an actual subtype.
if Full_Expander_Active then
Decl := Build_Actual_Subtype (T, Renamed_Object (Formal));
else
Decl := Build_Actual_Subtype (T, Formal);
end if;
if Present (Handled_Statement_Sequence (N)) then
First_Stmt :=
First (Statements (Handled_Statement_Sequence (N)));
Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
Mark_Rewrite_Insertion (Decl);
else
-- If the accept statement has no body, there will be no
-- reference to the actuals, so no need to compute actual
-- subtypes.
return;
end if;
else
Decl := Build_Actual_Subtype (T, Formal);
Prepend (Decl, Declarations (N));
Mark_Rewrite_Insertion (Decl);
end if;
-- The declaration uses the bounds of an existing object, and
-- therefore needs no constraint checks.
Analyze (Decl, Suppress => All_Checks);
-- We need to freeze manually the generated type when it is
-- inserted anywhere else than in a declarative part.
if Present (First_Stmt) then
Insert_List_Before_And_Analyze (First_Stmt,
Freeze_Entity (Defining_Identifier (Decl), N));
end if;
if Nkind (N) = N_Accept_Statement
and then Full_Expander_Active
then
Set_Actual_Subtype (Renamed_Object (Formal),
Defining_Identifier (Decl));
else
Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
end if;
end if;
Next_Formal (Formal);
end loop;
end Set_Actual_Subtypes;
---------------------
-- Set_Formal_Mode --
---------------------
procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
Spec : constant Node_Id := Parent (Formal_Id);
begin
-- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
-- since we ensure that corresponding actuals are always valid at the
-- point of the call.
if Out_Present (Spec) then
if Ekind (Scope (Formal_Id)) = E_Function
or else Ekind (Scope (Formal_Id)) = E_Generic_Function
then
-- [IN] OUT parameters allowed for functions in Ada 2012
if Ada_Version >= Ada_2012 then
-- Even in Ada 2012 operators can only have IN parameters
if Is_Operator_Symbol_Name (Chars (Scope (Formal_Id))) then
Error_Msg_N ("operators can only have IN parameters", Spec);
end if;
if In_Present (Spec) then
Set_Ekind (Formal_Id, E_In_Out_Parameter);
else
Set_Ekind (Formal_Id, E_Out_Parameter);
end if;
-- But not in earlier versions of Ada
else
Error_Msg_N ("functions can only have IN parameters", Spec);
Set_Ekind (Formal_Id, E_In_Parameter);
end if;
elsif In_Present (Spec) then
Set_Ekind (Formal_Id, E_In_Out_Parameter);
else
Set_Ekind (Formal_Id, E_Out_Parameter);
Set_Never_Set_In_Source (Formal_Id, True);
Set_Is_True_Constant (Formal_Id, False);
Set_Current_Value (Formal_Id, Empty);
end if;
else
Set_Ekind (Formal_Id, E_In_Parameter);
end if;
-- Set Is_Known_Non_Null for access parameters since the language
-- guarantees that access parameters are always non-null. We also set
-- Can_Never_Be_Null, since there is no way to change the value.
if Nkind (Parameter_Type (Spec)) = N_Access_Definition then
-- Ada 2005 (AI-231): In Ada 95, access parameters are always non-
-- null; In Ada 2005, only if then null_exclusion is explicit.
if Ada_Version < Ada_2005
or else Can_Never_Be_Null (Etype (Formal_Id))
then
Set_Is_Known_Non_Null (Formal_Id);
Set_Can_Never_Be_Null (Formal_Id);
end if;
-- Ada 2005 (AI-231): Null-exclusion access subtype
elsif Is_Access_Type (Etype (Formal_Id))
and then Can_Never_Be_Null (Etype (Formal_Id))
then
Set_Is_Known_Non_Null (Formal_Id);
-- We can also set Can_Never_Be_Null (thus preventing some junk
-- access checks) for the case of an IN parameter, which cannot
-- be changed, or for an IN OUT parameter, which can be changed but
-- not to a null value. But for an OUT parameter, the initial value
-- passed in can be null, so we can't set this flag in that case.
if Ekind (Formal_Id) /= E_Out_Parameter then
Set_Can_Never_Be_Null (Formal_Id);
end if;
end if;
Set_Mechanism (Formal_Id, Default_Mechanism);
Set_Formal_Validity (Formal_Id);
end Set_Formal_Mode;
-------------------------
-- Set_Formal_Validity --
-------------------------
procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
begin
-- If no validity checking, then we cannot assume anything about the
-- validity of parameters, since we do not know there is any checking
-- of the validity on the call side.
if not Validity_Checks_On then
return;
-- If validity checking for parameters is enabled, this means we are
-- not supposed to make any assumptions about argument values.
elsif Validity_Check_Parameters then
return;
-- If we are checking in parameters, we will assume that the caller is
-- also checking parameters, so we can assume the parameter is valid.
elsif Ekind (Formal_Id) = E_In_Parameter
and then Validity_Check_In_Params
then
Set_Is_Known_Valid (Formal_Id, True);
-- Similar treatment for IN OUT parameters
elsif Ekind (Formal_Id) = E_In_Out_Parameter
and then Validity_Check_In_Out_Params
then
Set_Is_Known_Valid (Formal_Id, True);
end if;
end Set_Formal_Validity;
------------------------
-- Subtype_Conformant --
------------------------
function Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean
is
Result : Boolean;
begin
Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result,
Skip_Controlling_Formals => Skip_Controlling_Formals);
return Result;
end Subtype_Conformant;
---------------------
-- Type_Conformant --
---------------------
function Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean
is
Result : Boolean;
begin
May_Hide_Profile := False;
Check_Conformance
(New_Id, Old_Id, Type_Conformant, False, Result,
Skip_Controlling_Formals => Skip_Controlling_Formals);
return Result;
end Type_Conformant;
-------------------------------
-- Valid_Operator_Definition --
-------------------------------
procedure Valid_Operator_Definition (Designator : Entity_Id) is
N : Integer := 0;
F : Entity_Id;
Id : constant Name_Id := Chars (Designator);
N_OK : Boolean;
begin
F := First_Formal (Designator);
while Present (F) loop
N := N + 1;
if Present (Default_Value (F)) then
Error_Msg_N
("default values not allowed for operator parameters",
Parent (F));
end if;
Next_Formal (F);
end loop;
-- Verify that user-defined operators have proper number of arguments
-- First case of operators which can only be unary
if Nam_In (Id, Name_Op_Not, Name_Op_Abs) then
N_OK := (N = 1);
-- Case of operators which can be unary or binary
elsif Nam_In (Id, Name_Op_Add, Name_Op_Subtract) then
N_OK := (N in 1 .. 2);
-- All other operators can only be binary
else
N_OK := (N = 2);
end if;
if not N_OK then
Error_Msg_N
("incorrect number of arguments for operator", Designator);
end if;
if Id = Name_Op_Ne
and then Base_Type (Etype (Designator)) = Standard_Boolean
and then not Is_Intrinsic_Subprogram (Designator)
then
Error_Msg_N
("explicit definition of inequality not allowed", Designator);
end if;
end Valid_Operator_Definition;
end Sem_Ch6;