| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- E X P _ S M E M -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1998-2013, 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 Atree; use Atree; |
| with Einfo; use Einfo; |
| with Exp_Ch7; use Exp_Ch7; |
| with Exp_Ch9; use Exp_Ch9; |
| with Exp_Tss; use Exp_Tss; |
| 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 (N : Node_Id; Call : Node_Id := Empty); |
| -- Insert a Shared_Var_ROpen call for variable before node N, unless |
| -- Call is a call to an init-proc, in which case the call is inserted |
| -- after Call. |
| |
| 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 subprogram call). |
| -- When Insert_Node is a function call, establish a transient scope around |
| -- the expression, and insert the write as an after-action of the transient |
| -- scope. |
| |
| 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 -- |
| -------------- |
| |
| procedure Add_Read (N : Node_Id; Call : Node_Id := Empty) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Ent : constant Node_Id := Entity (N); |
| SVC : Node_Id; |
| |
| begin |
| if Present (Shared_Var_Procs_Instance (Ent)) then |
| SVC := Build_Shared_Var_Proc_Call (Loc, Ent, Name_Read); |
| |
| if Present (Call) and then Is_Init_Proc (Name (Call)) then |
| Insert_After_And_Analyze (Call, SVC); |
| else |
| Insert_Action (N, SVC); |
| end if; |
| end if; |
| end Add_Read; |
| |
| ------------------------------- |
| -- 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 Entity_Id := Entity (N); |
| Par : constant Node_Id := Insert_Node; |
| begin |
| if Present (Shared_Var_Procs_Instance (Ent)) then |
| if Nkind (Insert_Node) = N_Function_Call then |
| Establish_Transient_Scope (Insert_Node, Sec_Stack => False); |
| Store_After_Actions_In_Scope (New_List ( |
| Build_Shared_Var_Proc_Call (Loc, Ent, Name_Write))); |
| else |
| Insert_After_And_Analyze (Par, |
| Build_Shared_Var_Proc_Call (Loc, Ent, Name_Write)); |
| end if; |
| 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 in general |
| -- we do: |
| |
| -- read |
| -- call |
| -- write |
| |
| -- but in the special case of a call to an init proc, we need to first |
| -- call the init proc (to set discriminants), then read (to possibly |
| -- set other components), then write (to record the updated components |
| -- to the backing store): |
| |
| -- init-proc-call |
| -- read |
| -- write |
| |
| elsif Is_Out_Actual (N) then |
| |
| -- Note: For an init proc call, Add_Read inserts just after the |
| -- call node, and we want to have first the read, then the write, |
| -- so we need to first Add_Write_After, then Add_Read. |
| |
| Add_Write_After (N); |
| Add_Read (N, Call => Insert_Node); |
| |
| -- All other cases are simple reads |
| |
| else |
| Add_Read (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 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_In (P, N_Indexed_Component, 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; |
