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|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ I N T R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2017, 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. --
-- --
------------------------------------------------------------------------------
-- Processing for intrinsic subprogram declarations
with Atree; use Atree;
with Einfo; use Einfo;
with Errout; use Errout;
with Lib; use Lib;
with Namet; use Namet;
with Opt; use Opt;
with Sem_Aux; use Sem_Aux;
with Sem_Eval; use Sem_Eval;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Uintp; use Uintp;
package body Sem_Intr is
-----------------------
-- Local Subprograms --
-----------------------
procedure Check_Exception_Function (E : Entity_Id; N : Node_Id);
-- Check use of intrinsic Exception_Message, Exception_Info or
-- Exception_Name, as used in the DEC compatible Current_Exceptions
-- package. In each case we must have a parameterless function that
-- returns type String.
procedure Check_Intrinsic_Operator (E : Entity_Id; N : Node_Id);
-- Check that operator is one of the binary arithmetic operators, and that
-- the types involved both have underlying integer types.
procedure Check_Shift (E : Entity_Id; N : Node_Id);
-- Check intrinsic shift subprogram, the two arguments are the same
-- as for Check_Intrinsic_Subprogram (i.e. the entity of the subprogram
-- declaration, and the node for the pragma argument, used for messages).
procedure Errint
(Msg : String; S : Node_Id; N : Node_Id; Relaxed : Boolean := False);
-- Post error message for bad intrinsic, the message itself is posted
-- on the appropriate spec node and another message is placed on the
-- pragma itself, referring to the spec. S is the node in the spec on
-- which the message is to be placed, and N is the pragma argument node.
-- Relaxed is True if the message should not be emitted in
-- Relaxed_RM_Semantics mode.
------------------------------
-- Check_Exception_Function --
------------------------------
procedure Check_Exception_Function (E : Entity_Id; N : Node_Id) is
begin
if not Ekind_In (E, E_Function, E_Generic_Function) then
Errint
("intrinsic exception subprogram must be a function", E, N);
elsif Present (First_Formal (E)) then
Errint
("intrinsic exception subprogram may not have parameters",
E, First_Formal (E));
return;
elsif Etype (E) /= Standard_String then
Errint
("return type of exception subprogram must be String", E, N);
return;
end if;
end Check_Exception_Function;
--------------------------
-- Check_Intrinsic_Call --
--------------------------
procedure Check_Intrinsic_Call (N : Node_Id) is
Nam : constant Entity_Id := Entity (Name (N));
Arg1 : constant Node_Id := First_Actual (N);
Typ : Entity_Id;
Rtyp : Entity_Id := Empty;
Cnam : Name_Id;
Unam : Node_Id;
begin
-- Set argument type if argument present
if Present (Arg1) then
Typ := Etype (Arg1);
Rtyp := Underlying_Type (Root_Type (Typ));
end if;
-- Set intrinsic name (getting original name in the generic case)
Unam := Ultimate_Alias (Nam);
if Present (Parent (Unam))
and then Present (Generic_Parent (Parent (Unam)))
then
Cnam := Chars (Generic_Parent (Parent (Unam)));
else
Cnam := Chars (Nam);
end if;
-- For Import_xxx calls, argument must be static string. A string
-- literal is legal even in Ada 83 mode, where such literals are
-- not static.
if Nam_In (Cnam, Name_Import_Address,
Name_Import_Largest_Value,
Name_Import_Value)
then
if Etype (Arg1) = Any_Type
or else Raises_Constraint_Error (Arg1)
then
null;
elsif Nkind (Arg1) /= N_String_Literal
and then not Is_OK_Static_Expression (Arg1)
then
Error_Msg_FE
("call to & requires static string argument!", N, Nam);
Why_Not_Static (Arg1);
elsif String_Length (Strval (Expr_Value_S (Arg1))) = 0 then
Error_Msg_NE
("call to & does not permit null string", N, Nam);
end if;
-- Check for the case of freeing a non-null object which will raise
-- Constraint_Error. Issue warning here, do the expansion in Exp_Intr.
elsif Cnam = Name_Unchecked_Deallocation
and then Can_Never_Be_Null (Etype (Arg1))
then
Error_Msg_N
("freeing `NOT NULL` object will raise Constraint_Error??", N);
-- For unchecked deallocation, error to deallocate from empty pool.
-- Note: this test used to be in Exp_Intr as a warning, but AI 157
-- issues a binding interpretation that this should be an error, and
-- consequently it needs to be done in the semantic analysis so that
-- the error is issued even in semantics only mode.
elsif Cnam = Name_Unchecked_Deallocation
and then No_Pool_Assigned (Rtyp)
then
Error_Msg_N ("deallocation from empty storage pool!", N);
-- For now, no other special checks are required
else
return;
end if;
end Check_Intrinsic_Call;
------------------------------
-- Check_Intrinsic_Operator --
------------------------------
procedure Check_Intrinsic_Operator (E : Entity_Id; N : Node_Id) is
Ret : constant Entity_Id := Etype (E);
Nam : constant Name_Id := Chars (E);
T1 : Entity_Id;
T2 : Entity_Id;
begin
-- Arithmetic operators
if Nam_In (Nam, Name_Op_Add, Name_Op_Subtract, Name_Op_Multiply,
Name_Op_Divide, Name_Op_Rem, Name_Op_Mod, Name_Op_Abs)
then
T1 := Etype (First_Formal (E));
if No (Next_Formal (First_Formal (E))) then
if Nam_In (Nam, Name_Op_Add, Name_Op_Subtract, Name_Op_Abs) then
T2 := T1;
-- Previous error in declaration
else
return;
end if;
else
T2 := Etype (Next_Formal (First_Formal (E)));
end if;
-- Same types, predefined operator will apply
if Root_Type (T1) = Root_Type (T2)
or else Root_Type (T1) = Root_Type (Ret)
then
null;
-- Expansion will introduce conversions if sizes are not equal
elsif Is_Integer_Type (Underlying_Type (T1))
and then Is_Integer_Type (Underlying_Type (T2))
and then Is_Integer_Type (Underlying_Type (Ret))
then
null;
else
Errint
("types of intrinsic operator operands do not match", E, N);
end if;
-- Comparison operators
elsif Nam_In (Nam, Name_Op_Eq, Name_Op_Ge, Name_Op_Gt, Name_Op_Le,
Name_Op_Lt, Name_Op_Ne)
then
T1 := Etype (First_Formal (E));
-- Return if previous error in declaration, otherwise get T2 type
if No (Next_Formal (First_Formal (E))) then
Check_Error_Detected;
return;
else
T2 := Etype (Next_Formal (First_Formal (E)));
end if;
if Root_Type (T1) /= Root_Type (T2) then
Errint
("types of intrinsic operator must have the same size", E, N);
end if;
if Root_Type (Ret) /= Standard_Boolean then
Errint
("result type of intrinsic comparison must be boolean", E, N);
end if;
-- Exponentiation
elsif Nam = Name_Op_Expon then
T1 := Etype (First_Formal (E));
if No (Next_Formal (First_Formal (E))) then
-- Previous error in declaration
return;
else
T2 := Etype (Next_Formal (First_Formal (E)));
end if;
if not (Is_Integer_Type (T1)
or else
Is_Floating_Point_Type (T1))
or else Root_Type (T1) /= Root_Type (Ret)
or else Root_Type (T2) /= Root_Type (Standard_Integer)
then
Errint ("incorrect operands for intrinsic operator", N, E);
end if;
-- All other operators (are there any?) are not handled
else
Errint ("incorrect context for ""Intrinsic"" convention", E, N);
return;
end if;
-- The type must be fully defined and numeric.
if No (Underlying_Type (T1))
or else not Is_Numeric_Type (Underlying_Type (T1))
then
Errint ("intrinsic operator can only apply to numeric types", E, N);
end if;
end Check_Intrinsic_Operator;
--------------------------------
-- Check_Intrinsic_Subprogram --
--------------------------------
procedure Check_Intrinsic_Subprogram (E : Entity_Id; N : Node_Id) is
Spec : constant Node_Id := Specification (Unit_Declaration_Node (E));
Nam : Name_Id;
begin
if Present (Spec)
and then Present (Generic_Parent (Spec))
then
Nam := Chars (Generic_Parent (Spec));
else
Nam := Chars (E);
end if;
-- Check name is valid intrinsic name
Get_Name_String (Nam);
if Name_Buffer (1) /= 'O'
and then Nam /= Name_Asm
and then Nam /= Name_To_Address
and then Nam not in First_Intrinsic_Name .. Last_Intrinsic_Name
then
Errint ("unrecognized intrinsic subprogram", E, N);
-- Shift cases. We allow user specification of intrinsic shift operators
-- for any numeric types.
elsif Nam_In (Nam, Name_Rotate_Left, Name_Rotate_Right, Name_Shift_Left,
Name_Shift_Right, Name_Shift_Right_Arithmetic)
then
Check_Shift (E, N);
-- We always allow intrinsic specifications in language defined units
-- and in expanded code. We assume that the GNAT implementors know what
-- they are doing, and do not write or generate junk use of intrinsic.
elsif not Comes_From_Source (E)
or else not Comes_From_Source (N)
or else In_Predefined_Unit (N)
then
null;
-- Exception functions
elsif Nam_In (Nam, Name_Exception_Information,
Name_Exception_Message,
Name_Exception_Name)
then
Check_Exception_Function (E, N);
-- Intrinsic operators
elsif Nkind (E) = N_Defining_Operator_Symbol then
Check_Intrinsic_Operator (E, N);
-- Source_Location and navigation functions
elsif Nam_In (Nam, Name_File,
Name_Line,
Name_Source_Location,
Name_Enclosing_Entity,
Name_Compilation_ISO_Date,
Name_Compilation_Date,
Name_Compilation_Time)
then
null;
-- For now, no other intrinsic subprograms are recognized in user code
else
Errint ("incorrect context for ""Intrinsic"" convention", E, N);
end if;
end Check_Intrinsic_Subprogram;
-----------------
-- Check_Shift --
-----------------
procedure Check_Shift (E : Entity_Id; N : Node_Id) is
Arg1 : Node_Id;
Arg2 : Node_Id;
Size : Nat;
Typ1 : Entity_Id;
Typ2 : Entity_Id;
Ptyp1 : Node_Id;
Ptyp2 : Node_Id;
begin
if not Ekind_In (E, E_Function, E_Generic_Function) then
Errint ("intrinsic shift subprogram must be a function", E, N);
return;
end if;
Arg1 := First_Formal (E);
if Present (Arg1) then
Arg2 := Next_Formal (Arg1);
else
Arg2 := Empty;
end if;
if Arg1 = Empty or else Arg2 = Empty then
Errint ("intrinsic shift function must have two arguments", E, N);
return;
end if;
Typ1 := Etype (Arg1);
Typ2 := Etype (Arg2);
Ptyp1 := Parameter_Type (Parent (Arg1));
Ptyp2 := Parameter_Type (Parent (Arg2));
if not Is_Integer_Type (Typ1) then
Errint ("first argument to shift must be integer type", Ptyp1, N);
return;
end if;
if Typ2 /= Standard_Natural then
Errint ("second argument to shift must be type Natural", Ptyp2, N);
return;
end if;
-- type'Size (not 'Object_Size) must be one of the allowed values
Size := UI_To_Int (RM_Size (Typ1));
if Size /= 8 and then
Size /= 16 and then
Size /= 32 and then
Size /= 64
then
Errint
("first argument for shift must have size 8, 16, 32 or 64",
Ptyp1, N, Relaxed => True);
return;
elsif Non_Binary_Modulus (Typ1) then
Errint ("shifts not allowed for nonbinary modular types", Ptyp1, N);
-- For modular type, modulus must be 2**8, 2**16, 2**32, or 2**64.
-- Don't apply to generic types, since we may not have a modulus value.
elsif Is_Modular_Integer_Type (Typ1)
and then not Is_Generic_Type (Typ1)
and then Modulus (Typ1) /= Uint_2 ** 8
and then Modulus (Typ1) /= Uint_2 ** 16
and then Modulus (Typ1) /= Uint_2 ** 32
and then Modulus (Typ1) /= Uint_2 ** 64
then
Errint
("modular type for shift must have modulus of 2'*'*8, "
& "2'*'*16, 2'*'*32, or 2'*'*64", Ptyp1, N, Relaxed => True);
elsif Etype (Arg1) /= Etype (E) then
Errint
("first argument of shift must match return type", Ptyp1, N);
return;
end if;
Set_Has_Shift_Operator (Base_Type (Typ1));
end Check_Shift;
------------
-- Errint --
------------
procedure Errint
(Msg : String; S : Node_Id; N : Node_Id; Relaxed : Boolean := False) is
begin
-- Ignore errors on Intrinsic in Relaxed_RM_Semantics mode where we can
-- be more liberal.
if not (Relaxed and Relaxed_RM_Semantics) then
Error_Msg_N (Msg, S);
Error_Msg_N ("incorrect intrinsic subprogram, see spec", N);
end if;
end Errint;
end Sem_Intr;
|