------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ S M E M --
-- --
-- B o d y --
-- --
-- Copyright (C) 1998-2010, 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 Atree; use Atree;
with Einfo; use Einfo;
with Exp_Ch9; use Exp_Ch9;
with Exp_Util; use Exp_Util;
with Nmake; use Nmake;
with Namet; use Namet;
with Nlists; use Nlists;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Stringt; use Stringt;
with Tbuild; use Tbuild;
package body Exp_Smem is
Insert_Node : Node_Id;
-- Node after which a write call is to be inserted
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_Read_Before (N : Node_Id);
-- Insert a Shared_Var_ROpen call for variable before node N
procedure Add_Write_After (N : Node_Id);
-- Insert a Shared_Var_WOpen call for variable after the node
-- Insert_Node, as recorded by On_Lhs_Of_Assignment (where it points
-- to the assignment statement) or Is_Out_Actual (where it points to
-- the procedure call statement).
procedure Build_Full_Name (E : Entity_Id; N : out String_Id);
-- Build the fully qualified string name of a shared variable
function On_Lhs_Of_Assignment (N : Node_Id) return Boolean;
-- Determines if N is on the left hand of the assignment. This means
-- that either it is a simple variable, or it is a record or array
-- variable with a corresponding selected or indexed component on
-- the left side of an assignment. If the result is True, then
-- Insert_Node is set to point to the assignment
function Is_Out_Actual (N : Node_Id) return Boolean;
-- In a similar manner, this function determines if N appears as an
-- OUT or IN OUT parameter to a procedure call. If the result is
-- True, then Insert_Node is set to point to the call.
function Build_Shared_Var_Proc_Call
(Loc : Source_Ptr;
E : Node_Id;
N : Name_Id) return Node_Id;
-- Build a call to support procedure N for shared object E (provided by
-- the instance of System.Shared_Storage.Shared_Var_Procs associated to E).
--------------------------------
-- Build_Shared_Var_Proc_Call --
--------------------------------
function Build_Shared_Var_Proc_Call
(Loc : Source_Ptr;
E : Entity_Id;
N : Name_Id) return Node_Id is
begin
return Make_Procedure_Call_Statement (Loc,
Name => Make_Selected_Component (Loc,
Prefix =>
New_Occurrence_Of (Shared_Var_Procs_Instance (E), Loc),
Selector_Name => Make_Identifier (Loc, N)));
end Build_Shared_Var_Proc_Call;
---------------------
-- Add_Read_Before --
---------------------
procedure Add_Read_Before (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Node_Id := Entity (N);
begin
if Present (Shared_Var_Procs_Instance (Ent)) then
Insert_Action (N, Build_Shared_Var_Proc_Call (Loc, Ent, Name_Read));
end if;
end Add_Read_Before;
-------------------------------
-- Add_Shared_Var_Lock_Procs --
-------------------------------
procedure Add_Shared_Var_Lock_Procs (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Obj : constant Entity_Id := Entity (Expression (First_Actual (N)));
Inode : Node_Id;
Vnm : String_Id;
begin
-- We have to add Shared_Var_Lock and Shared_Var_Unlock calls around
-- the procedure or function call node. First we locate the right
-- place to do the insertion, which is the call itself in the
-- procedure call case, or else the nearest non subexpression
-- node that contains the function call.
Inode := N;
while Nkind (Inode) /= N_Procedure_Call_Statement
and then Nkind (Inode) in N_Subexpr
loop
Inode := Parent (Inode);
end loop;
-- Now insert the Lock and Unlock calls and the read/write calls
-- Two concerns here. First we are not dealing with the exception
-- case, really we need some kind of cleanup routine to do the
-- Unlock. Second, these lock calls should be inside the protected
-- object processing, not outside, otherwise they can be done at
-- the wrong priority, resulting in dead lock situations ???
Build_Full_Name (Obj, Vnm);
-- First insert the Lock call before
Insert_Before_And_Analyze (Inode,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (RTE (RE_Shared_Var_Lock), Loc),
Parameter_Associations => New_List (
Make_String_Literal (Loc, Vnm))));
-- Now, right after the Lock, insert a call to read the object
Insert_Before_And_Analyze (Inode,
Build_Shared_Var_Proc_Call (Loc, Obj, Name_Read));
-- Now insert the Unlock call after
Insert_After_And_Analyze (Inode,
Make_Procedure_Call_Statement (Loc,
Name => New_Occurrence_Of (RTE (RE_Shared_Var_Unlock), Loc),
Parameter_Associations => New_List (
Make_String_Literal (Loc, Vnm))));
-- Now for a procedure call, but not a function call, insert the
-- call to write the object just before the unlock.
if Nkind (N) = N_Procedure_Call_Statement then
Insert_After_And_Analyze (Inode,
Build_Shared_Var_Proc_Call (Loc, Obj, Name_Write));
end if;
end Add_Shared_Var_Lock_Procs;
---------------------
-- Add_Write_After --
---------------------
procedure Add_Write_After (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Node_Id := Entity (N);
begin
if Present (Shared_Var_Procs_Instance (Ent)) then
Insert_After_And_Analyze (Insert_Node,
Build_Shared_Var_Proc_Call (Loc, Ent, Name_Write));
end if;
end Add_Write_After;
---------------------
-- Build_Full_Name --
---------------------
procedure Build_Full_Name (E : Entity_Id; N : out String_Id) is
procedure Build_Name (E : Entity_Id);
-- This is a recursive routine used to construct the fully qualified
-- string name of the package corresponding to the shared variable.
----------------
-- Build_Name --
----------------
procedure Build_Name (E : Entity_Id) is
begin
if Scope (E) /= Standard_Standard then
Build_Name (Scope (E));
Store_String_Char ('.');
end if;
Get_Decoded_Name_String (Chars (E));
Store_String_Chars (Name_Buffer (1 .. Name_Len));
end Build_Name;
-- Start of processing for Build_Full_Name
begin
Start_String;
Build_Name (E);
N := End_String;
end Build_Full_Name;
------------------------------------
-- Expand_Shared_Passive_Variable --
------------------------------------
procedure Expand_Shared_Passive_Variable (N : Node_Id) is
Typ : constant Entity_Id := Etype (N);
begin
-- Nothing to do for protected or limited objects
if Is_Limited_Type (Typ) or else Is_Concurrent_Type (Typ) then
return;
-- If we are on the left hand side of an assignment, then we add
-- the write call after the assignment.
elsif On_Lhs_Of_Assignment (N) then
Add_Write_After (N);
-- If we are a parameter for an out or in out formal, then put
-- the read before and the write after.
elsif Is_Out_Actual (N) then
Add_Read_Before (N);
Add_Write_After (N);
-- All other cases are simple reads
else
Add_Read_Before (N);
end if;
end Expand_Shared_Passive_Variable;
-------------------
-- Is_Out_Actual --
-------------------
function Is_Out_Actual (N : Node_Id) return Boolean is
Formal : Entity_Id;
Call : Node_Id;
begin
Find_Actual (N, Formal, Call);
if No (Formal) then
return False;
else
if Ekind_In (Formal, E_Out_Parameter, E_In_Out_Parameter) then
Insert_Node := Call;
return True;
else
return False;
end if;
end if;
end Is_Out_Actual;
---------------------------
-- Make_Shared_Var_Procs --
---------------------------
function Make_Shared_Var_Procs (N : Node_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (N);
Ent : constant Entity_Id := Defining_Identifier (N);
Typ : constant Entity_Id := Etype (Ent);
Vnm : String_Id;
Obj : Node_Id;
Obj_Typ : Entity_Id;
After : constant Node_Id := Next (N);
-- Node located right after N originally (after insertion of the SV
-- procs this node is right after the last inserted node).
SVP_Instance : constant Entity_Id := Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Ent), 'G'));
-- Instance of System.Shared_Storage.Shared_Var_Procs associated
-- with Ent.
Instantiation : Node_Id;
-- Package instantiation node for SVP_Instance
-- Start of processing for Make_Shared_Var_Procs
begin
Build_Full_Name (Ent, Vnm);
-- We turn off Shared_Passive during construction and analysis of
-- the generic package instantiation, to avoid improper attempts to
-- process the variable references within these instantiation.
Set_Is_Shared_Passive (Ent, False);
-- Construct generic package instantiation
-- package varG is new Shared_Var_Procs (typ, var, "pkg.var");
Obj := New_Occurrence_Of (Ent, Loc);
Obj_Typ := Typ;
if Is_Concurrent_Type (Typ) then
Obj := Convert_Concurrent (N => Obj, Typ => Typ);
Obj_Typ := Corresponding_Record_Type (Typ);
end if;
Instantiation :=
Make_Package_Instantiation (Loc,
Defining_Unit_Name => SVP_Instance,
Name =>
New_Occurrence_Of (RTE (RE_Shared_Var_Procs), Loc),
Generic_Associations => New_List (
Make_Generic_Association (Loc,
Explicit_Generic_Actual_Parameter =>
New_Occurrence_Of (Obj_Typ, Loc)),
Make_Generic_Association (Loc,
Explicit_Generic_Actual_Parameter => Obj),
Make_Generic_Association (Loc,
Explicit_Generic_Actual_Parameter =>
Make_String_Literal (Loc, Vnm))));
Insert_After_And_Analyze (N, Instantiation);
Set_Is_Shared_Passive (Ent, True);
Set_Shared_Var_Procs_Instance
(Ent, Defining_Entity (Instance_Spec (Instantiation)));
-- Return last node before After
declare
Nod : Node_Id := Next (N);
begin
while Next (Nod) /= After loop
Nod := Next (Nod);
end loop;
return Nod;
end;
end Make_Shared_Var_Procs;
--------------------------
-- On_Lhs_Of_Assignment --
--------------------------
function On_Lhs_Of_Assignment (N : Node_Id) return Boolean is
P : constant Node_Id := Parent (N);
begin
if Nkind (P) = N_Assignment_Statement then
if N = Name (P) then
Insert_Node := P;
return True;
else
return False;
end if;
elsif (Nkind (P) = N_Indexed_Component
or else
Nkind (P) = N_Selected_Component)
and then N = Prefix (P)
then
return On_Lhs_Of_Assignment (P);
else
return False;
end if;
end On_Lhs_Of_Assignment;
end Exp_Smem;