| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S T R U B -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2021-2022, 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Package containing utility procedures related to Stack Scrubbing |
| |
| with Atree; use Atree; |
| with Einfo; use Einfo; |
| with Einfo.Entities; use Einfo.Entities; |
| with Errout; use Errout; |
| with Namet; use Namet; |
| with Nlists; use Nlists; |
| with Sem_Eval; use Sem_Eval; |
| with Sinfo; use Sinfo; |
| with Sinfo.Nodes; use Sinfo.Nodes; |
| with Sinfo.Utils; use Sinfo.Utils; |
| with Snames; use Snames; |
| with Stringt; use Stringt; |
| |
| package body Strub is |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Find_Explicit_Strub_Pragma (Id : Entity_Id) return Node_Id; |
| -- Return a pragma Machine_Attribute (Id, "strub"[, "mode"]) node |
| -- if Id has one. |
| |
| function Strub_Pragma_Arg (Item : Node_Id) return Node_Id is |
| (Get_Pragma_Arg |
| (Next (Next (First (Pragma_Argument_Associations (Item)))))); |
| -- Return the pragma argument holding the strub mode associated |
| -- with Item, a subprogram, variable, constant, or type. Bear in |
| -- mind that strub pragmas with an explicit strub mode argument, |
| -- naming access-to-subprogram types, are applied to the |
| -- designated subprogram type. |
| |
| function Strub_Pragma_Arg_To_String (Item : Node_Id) return String is |
| (To_String (Strval (Expr_Value_S (Item)))); |
| -- Extract and return as a String the strub mode held in a node |
| -- returned by Strub_Pragma_Arg. |
| |
| function Strub_Pragma_Mode |
| (Id : Entity_Id; |
| Item : Node_Id) return Strub_Mode; |
| -- Return the strub mode associated with Item expressed in Id. |
| -- Strub_Pragma_P (Id) must hold. |
| |
| --------------------------- |
| -- Check_Same_Strub_Mode -- |
| --------------------------- |
| |
| procedure Check_Same_Strub_Mode |
| (Dest, Src : Entity_Id; |
| Report : Boolean := True) |
| is |
| Src_Strub_Mode : constant Strub_Mode := Explicit_Strub_Mode (Src); |
| Dest_Strub_Mode : constant Strub_Mode := Explicit_Strub_Mode (Dest); |
| |
| begin |
| if Dest_Strub_Mode = Src_Strub_Mode then |
| return; |
| end if; |
| |
| -- Internal is not part of the interface, it's an *internal* |
| -- implementation detail, so consider it equivalent to unspecified here. |
| -- ??? -fstrub=relaxed|strict makes them interface-equivalent to |
| -- Callable or Disabled, respectively, but we don't look at that flag in |
| -- the front-end, and it seems undesirable for that flag to affect |
| -- whether specifications are conformant. Maybe there should be some |
| -- means to specify Callable or Disabled along with Internal? |
| |
| if Dest_Strub_Mode in Unspecified | Internal |
| and then Src_Strub_Mode in Unspecified | Internal |
| then |
| return; |
| end if; |
| |
| if not Report then |
| return; |
| end if; |
| |
| if Src_Strub_Mode /= Unspecified then |
| Error_Msg_Sloc := Sloc (Find_Explicit_Strub_Pragma (Src)); |
| else |
| Error_Msg_Sloc := Sloc (Src); |
| end if; |
| Error_Msg_Node_2 := Src; |
| Error_Msg_NE ("& requires the same `strub` mode as &#", |
| (if Dest_Strub_Mode /= Unspecified |
| then Find_Explicit_Strub_Pragma (Dest) |
| else Dest), |
| Dest); |
| end Check_Same_Strub_Mode; |
| |
| ---------------------------- |
| -- Compatible_Strub_Modes -- |
| ---------------------------- |
| |
| function Compatible_Strub_Modes |
| (Dest, Src : Entity_Id) return Boolean |
| is |
| Src_Strub_Mode : constant Strub_Mode := Explicit_Strub_Mode (Src); |
| Dest_Strub_Mode : constant Strub_Mode := Explicit_Strub_Mode (Dest); |
| |
| begin |
| return Src_Strub_Mode = Dest_Strub_Mode |
| or else At_Calls not in Src_Strub_Mode | Dest_Strub_Mode; |
| end Compatible_Strub_Modes; |
| |
| --------------------- |
| -- Copy_Strub_Mode -- |
| --------------------- |
| |
| procedure Copy_Strub_Mode (Dest, Src : Entity_Id) is |
| Strub : Node_Id := Find_Explicit_Strub_Pragma (Src); |
| Src_Strub_Mode : constant Strub_Mode := Strub_Pragma_Mode (Src, Strub); |
| |
| begin |
| pragma Assert (Explicit_Strub_Mode (Dest) = Unspecified); |
| |
| -- Refrain from copying Internal to subprogram types. |
| -- It affects code generation for the subprogram, |
| -- but it has no effect on its type or interface. |
| |
| if Src_Strub_Mode = Unspecified |
| or else (Ekind (Dest) = E_Subprogram_Type |
| and then Src_Strub_Mode = Internal) |
| then |
| return; |
| end if; |
| |
| Strub := New_Copy (Strub); |
| Set_Next_Rep_Item (Strub, First_Rep_Item (Dest)); |
| Set_First_Rep_Item (Dest, Strub); |
| Set_Has_Gigi_Rep_Item (Dest); |
| end Copy_Strub_Mode; |
| |
| ------------------------- |
| -- Explicit_Strub_Mode -- |
| ------------------------- |
| |
| function Explicit_Strub_Mode (Id : Entity_Id) return Strub_Mode is |
| Item : constant Node_Id := Find_Explicit_Strub_Pragma (Id); |
| |
| begin |
| return Strub_Pragma_Mode (Id, Item); |
| end Explicit_Strub_Mode; |
| |
| -------------------------------- |
| -- Find_Explicit_Strub_Pragma -- |
| -------------------------------- |
| |
| function Find_Explicit_Strub_Pragma (Id : Entity_Id) return Node_Id is |
| Item : Node_Id; |
| |
| begin |
| if not Has_Gigi_Rep_Item (Id) then |
| return Empty; |
| end if; |
| |
| Item := First_Rep_Item (Id); |
| while Present (Item) loop |
| if Strub_Pragma_P (Item) then |
| return Item; |
| end if; |
| Item := Next_Rep_Item (Item); |
| end loop; |
| |
| return Empty; |
| end Find_Explicit_Strub_Pragma; |
| |
| ----------------------- |
| -- Strub_Pragma_Mode -- |
| ----------------------- |
| |
| function Strub_Pragma_Mode |
| (Id : Entity_Id; |
| Item : Node_Id) return Strub_Mode |
| is |
| Arg : Node_Id := Empty; |
| |
| begin |
| -- ??? Enumeration literals, despite being conceptually functions, have |
| -- neither bodies nor stack frames, and it's not clear whether it would |
| -- make more sense to treat them as subprograms or as constants, but |
| -- they can be renamed as functions. Should we require all literals of |
| -- a type to have the same strub mode? Rule out their annotation? |
| |
| if Ekind (Id) in E_Subprogram_Type |
| | Overloadable_Kind |
| | Generic_Subprogram_Kind |
| then |
| if Item = Empty then |
| return Unspecified; |
| end if; |
| |
| Arg := Strub_Pragma_Arg (Item); |
| if Arg = Empty then |
| return At_Calls; |
| end if; |
| |
| declare |
| Str : constant String := Strub_Pragma_Arg_To_String (Arg); |
| begin |
| if Str'Length /= 8 then |
| return Unspecified; |
| end if; |
| |
| case Str (Str'First) is |
| when 'a' => |
| if Str = "at-calls" then |
| return At_Calls; |
| end if; |
| |
| when 'i' => |
| if Str = "internal" then |
| return Internal; |
| end if; |
| |
| when 'c' => |
| if Str = "callable" then |
| return Callable; |
| end if; |
| |
| when 'd' => |
| if Str = "disabled" then |
| return Disabled; |
| end if; |
| |
| when others => |
| null; |
| end case; |
| return Unspecified; |
| end; |
| |
| -- Access-to-subprogram types and variables can be treated just like |
| -- other access types, because the pragma logic has already promoted to |
| -- subprogram types any annotations applicable to them. |
| |
| elsif Ekind (Id) in Type_Kind -- except E_Subprogram_Type, covered above |
| | Scalar_Kind |
| | Object_Kind |
| | Named_Kind |
| then |
| if Item = Empty then |
| return Unspecified; |
| end if; |
| |
| Arg := Strub_Pragma_Arg (Item); |
| if Arg /= Empty then |
| -- A strub parameter is not applicable to variables, |
| -- and will be ignored. |
| |
| return Unspecified; |
| end if; |
| |
| return Enabled; |
| |
| else |
| pragma Assert (Item = Empty); |
| return Not_Applicable; |
| end if; |
| end Strub_Pragma_Mode; |
| |
| -------------------- |
| -- Strub_Pragma_P -- |
| -------------------- |
| |
| function Strub_Pragma_P |
| (Item : Node_Id) return Boolean is |
| (Nkind (Item) = N_Pragma |
| and then Pragma_Name (Item) = Name_Machine_Attribute |
| and then |
| Strub_Pragma_Arg_To_String |
| (Get_Pragma_Arg |
| (Next (First (Pragma_Argument_Associations (Item))))) |
| = "strub"); |
| |
| end Strub; |
