+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- E X P _ C H 2 --
--- --
--- B o d y --
--- --
--- $Revision: 1.2.10.1 $
--- --
--- Copyright (C) 1992-2001 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 2, 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 COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
--- --
--- 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 Elists; use Elists;
-with Exp_Smem; use Exp_Smem;
-with Exp_Util; use Exp_Util;
-with Exp_VFpt; use Exp_VFpt;
-with Nmake; use Nmake;
-with Sem; use Sem;
-with Sem_Res; use Sem_Res;
-with Sem_Util; use Sem_Util;
-with Sinfo; use Sinfo;
-with Tbuild; use Tbuild;
-with Snames; use Snames;
-
-package body Exp_Ch2 is
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- procedure Expand_Discriminant (N : Node_Id);
- -- An occurrence of a discriminant within a discriminated type is replaced
- -- with the corresponding discriminal, that is to say the formal parameter
- -- of the initialization procedure for the type that is associated with
- -- that particular discriminant. This replacement is not performed for
- -- discriminants of records that appear in constraints of component of the
- -- record, because Gigi uses the discriminant name to retrieve its value.
- -- In the other hand, it has to be performed for default expressions of
- -- components because they are used in the record init procedure. See
- -- Einfo for more details, and Exp_Ch3, Exp_Ch9 for examples of use.
- -- For discriminants of tasks and protected types, the transformation is
- -- more complex when it occurs within a default expression for an entry
- -- or protected operation. The corresponding default_expression_function
- -- has an additional parameter which is the target of an entry call, and
- -- the discriminant of the task must be replaced with a reference to the
- -- discriminant of that formal parameter.
-
- procedure Expand_Entity_Reference (N : Node_Id);
- -- Common processing for expansion of identifiers and expanded names
-
- procedure Expand_Entry_Index_Parameter (N : Node_Id);
- -- A reference to the identifier in the entry index specification
- -- of a protected entry body is modified to a reference to a constant
- -- definintion equal to the index of the entry family member being
- -- called. This constant is calculated as part of the elaboration
- -- of the expanded code for the body, and is calculated from the
- -- object-wide entry index returned by Next_Entry_Call.
-
- procedure Expand_Entry_Parameter (N : Node_Id);
- -- A reference to an entry parameter is modified to be a reference to
- -- the corresponding component of the entry parameter record that is
- -- passed by the runtime to the accept body procedure
-
- procedure Expand_Formal (N : Node_Id);
- -- A reference to a formal parameter of a protected subprogram is
- -- expanded to the corresponding formal of the unprotected procedure
- -- used to represent the protected subprogram within the protected object.
-
- procedure Expand_Protected_Private (N : Node_Id);
- -- A reference to a private object of a protected type is expanded
- -- to a component selected from the record used to implement
- -- the protected object. Such a record is passed to all operations
- -- on a protected object in a parameter named _object. Such an object
- -- is a constant within a function, and a variable otherwise.
-
- procedure Expand_Renaming (N : Node_Id);
- -- For renamings, just replace the identifier by the corresponding
- -- name expression. Note that this has been evaluated (see routine
- -- Exp_Ch8.Expand_N_Object_Renaming.Evaluate_Name) so this gives
- -- the correct renaming semantics.
-
- -------------------------
- -- Expand_Discriminant --
- -------------------------
-
- procedure Expand_Discriminant (N : Node_Id) is
- Scop : constant Entity_Id := Scope (Entity (N));
- P : Node_Id := N;
- Parent_P : Node_Id := Parent (P);
- In_Entry : Boolean := False;
-
- begin
- -- The Incomplete_Or_Private_Kind happens while resolving the
- -- discriminant constraint involved in a derived full type,
- -- such as:
-
- -- type D is private;
- -- type D(C : ...) is new T(C);
-
- if Ekind (Scop) = E_Record_Type
- or Ekind (Scop) in Incomplete_Or_Private_Kind
- then
-
- -- Find the origin by walking up the tree till the component
- -- declaration
-
- while Present (Parent_P)
- and then Nkind (Parent_P) /= N_Component_Declaration
- loop
- P := Parent_P;
- Parent_P := Parent (P);
- end loop;
-
- -- If the discriminant reference was part of the default expression
- -- it has to be "discriminalized"
-
- if Present (Parent_P) and then P = Expression (Parent_P) then
- Set_Entity (N, Discriminal (Entity (N)));
- end if;
-
- elsif Is_Concurrent_Type (Scop) then
- while Present (Parent_P)
- and then Nkind (Parent_P) /= N_Subprogram_Body
- loop
- P := Parent_P;
-
- if Nkind (P) = N_Entry_Declaration then
- In_Entry := True;
- end if;
-
- Parent_P := Parent (Parent_P);
- end loop;
-
- -- If the discriminant occurs within the default expression for
- -- a formal of an entry or protected operation, create a default
- -- function for it, and replace the discriminant with a reference
- -- to the discriminant of the formal of the default function.
- -- The discriminant entity is the one defined in the corresponding
- -- record.
-
- if Present (Parent_P)
- and then Present (Corresponding_Spec (Parent_P))
- then
-
- declare
- Loc : constant Source_Ptr := Sloc (N);
- D_Fun : Entity_Id := Corresponding_Spec (Parent_P);
- Formal : Entity_Id := First_Formal (D_Fun);
- New_N : Node_Id;
- Disc : Entity_Id;
-
- begin
- -- Verify that we are within a default function: the type of
- -- its formal parameter is the same task or protected type.
-
- if Present (Formal)
- and then Etype (Formal) = Scope (Entity (N))
- then
- Disc := CR_Discriminant (Entity (N));
-
- New_N :=
- Make_Selected_Component (Loc,
- Prefix => New_Occurrence_Of (Formal, Loc),
- Selector_Name => New_Occurrence_Of (Disc, Loc));
-
- Set_Etype (New_N, Etype (N));
- Rewrite (N, New_N);
-
- else
- Set_Entity (N, Discriminal (Entity (N)));
- end if;
- end;
-
- elsif Nkind (Parent (N)) = N_Range
- and then In_Entry
- then
- Set_Entity (N, CR_Discriminant (Entity (N)));
- else
- Set_Entity (N, Discriminal (Entity (N)));
- end if;
-
- else
- Set_Entity (N, Discriminal (Entity (N)));
- end if;
- end Expand_Discriminant;
-
- -----------------------------
- -- Expand_Entity_Reference --
- -----------------------------
-
- procedure Expand_Entity_Reference (N : Node_Id) is
- E : constant Entity_Id := Entity (N);
-
- begin
- if Ekind (E) = E_Discriminant then
- Expand_Discriminant (N);
-
- elsif Is_Entry_Formal (E) then
- Expand_Entry_Parameter (N);
-
- elsif Ekind (E) = E_Component
- and then Is_Protected_Private (E)
- then
- Expand_Protected_Private (N);
-
- elsif Ekind (E) = E_Entry_Index_Parameter then
- Expand_Entry_Index_Parameter (N);
-
- elsif Is_Formal (E) then
- Expand_Formal (N);
-
- elsif Is_Renaming_Of_Object (E) then
- Expand_Renaming (N);
-
- elsif Ekind (E) = E_Variable
- and then Is_Shared_Passive (E)
- then
- Expand_Shared_Passive_Variable (N);
- end if;
- end Expand_Entity_Reference;
-
- ----------------------------------
- -- Expand_Entry_Index_Parameter --
- ----------------------------------
-
- procedure Expand_Entry_Index_Parameter (N : Node_Id) is
- begin
- Set_Entity (N, Entry_Index_Constant (Entity (N)));
- end Expand_Entry_Index_Parameter;
-
- ----------------------------
- -- Expand_Entry_Parameter --
- ----------------------------
-
- procedure Expand_Entry_Parameter (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- Ent_Formal : constant Entity_Id := Entity (N);
- Ent_Spec : constant Entity_Id := Scope (Ent_Formal);
- Parm_Type : constant Entity_Id := Entry_Parameters_Type (Ent_Spec);
- Acc_Stack : constant Elist_Id := Accept_Address (Ent_Spec);
- Addr_Ent : constant Entity_Id := Node (Last_Elmt (Acc_Stack));
- P_Comp_Ref : Entity_Id;
-
- begin
- -- What we need is a reference to the corresponding component of the
- -- parameter record object. The Accept_Address field of the entry
- -- entity references the address variable that contains the address
- -- of the accept parameters record. We first have to do an unchecked
- -- conversion to turn this into a pointer to the parameter record and
- -- then we select the required parameter field.
-
- P_Comp_Ref :=
- Make_Selected_Component (Loc,
- Prefix =>
- Unchecked_Convert_To (Parm_Type,
- New_Reference_To (Addr_Ent, Loc)),
- Selector_Name =>
- New_Reference_To (Entry_Component (Ent_Formal), Loc));
-
- -- For all types of parameters, the constructed parameter record
- -- object contains a pointer to the parameter. Thus we must
- -- dereference them to access them (this will often be redundant,
- -- since the needed deference is implicit, but no harm is done by
- -- making it explicit).
-
- Rewrite (N,
- Make_Explicit_Dereference (Loc, P_Comp_Ref));
-
- Analyze (N);
- end Expand_Entry_Parameter;
-
- -------------------
- -- Expand_Formal --
- -------------------
-
- procedure Expand_Formal (N : Node_Id) is
- E : constant Entity_Id := Entity (N);
- Subp : constant Entity_Id := Scope (E);
-
- begin
- if Is_Protected_Type (Scope (Subp))
- and then Chars (Subp) /= Name_uInit_Proc
- and then Present (Protected_Formal (E))
- then
- Set_Entity (N, Protected_Formal (E));
- end if;
- end Expand_Formal;
-
- ----------------------------
- -- Expand_N_Expanded_Name --
- ----------------------------
-
- procedure Expand_N_Expanded_Name (N : Node_Id) is
- begin
- Expand_Entity_Reference (N);
- end Expand_N_Expanded_Name;
-
- -------------------------
- -- Expand_N_Identifier --
- -------------------------
-
- procedure Expand_N_Identifier (N : Node_Id) is
- begin
- Expand_Entity_Reference (N);
- end Expand_N_Identifier;
-
- ---------------------------
- -- Expand_N_Real_Literal --
- ---------------------------
-
- procedure Expand_N_Real_Literal (N : Node_Id) is
- begin
- if Vax_Float (Etype (N)) then
- Expand_Vax_Real_Literal (N);
- end if;
- end Expand_N_Real_Literal;
-
- ------------------------------
- -- Expand_Protected_Private --
- ------------------------------
-
- procedure Expand_Protected_Private (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- E : constant Entity_Id := Entity (N);
- Op : constant Node_Id := Protected_Operation (E);
- Scop : Entity_Id;
- Lo : Node_Id;
- Hi : Node_Id;
- D_Range : Node_Id;
-
- begin
- if Nkind (Op) /= N_Subprogram_Body
- or else Nkind (Specification (Op)) /= N_Function_Specification
- then
- Set_Ekind (Prival (E), E_Variable);
- else
- Set_Ekind (Prival (E), E_Constant);
- end if;
-
- -- If the private component appears in an assignment (either lhs or
- -- rhs) and is a one-dimensional array constrained by a discriminant,
- -- rewrite as P (Lo .. Hi) with an explicit range, so that discriminal
- -- is directly visible. This solves delicate visibility problems.
-
- if Comes_From_Source (N)
- and then Is_Array_Type (Etype (E))
- and then Number_Dimensions (Etype (E)) = 1
- and then not Within_Init_Proc
- then
- Lo := Type_Low_Bound (Etype (First_Index (Etype (E))));
- Hi := Type_High_Bound (Etype (First_Index (Etype (E))));
-
- if Nkind (Parent (N)) = N_Assignment_Statement
- and then ((Is_Entity_Name (Lo)
- and then Ekind (Entity (Lo)) = E_In_Parameter)
- or else (Is_Entity_Name (Hi)
- and then
- Ekind (Entity (Hi)) = E_In_Parameter))
- then
- D_Range := New_Node (N_Range, Loc);
-
- if Is_Entity_Name (Lo)
- and then Ekind (Entity (Lo)) = E_In_Parameter
- then
- Set_Low_Bound (D_Range,
- Make_Identifier (Loc, Chars (Entity (Lo))));
- else
- Set_Low_Bound (D_Range, Duplicate_Subexpr (Lo));
- end if;
-
- if Is_Entity_Name (Hi)
- and then Ekind (Entity (Hi)) = E_In_Parameter
- then
- Set_High_Bound (D_Range,
- Make_Identifier (Loc, Chars (Entity (Hi))));
- else
- Set_High_Bound (D_Range, Duplicate_Subexpr (Hi));
- end if;
-
- Rewrite (N,
- Make_Slice (Loc,
- Prefix => New_Occurrence_Of (E, Loc),
- Discrete_Range => D_Range));
-
- Analyze_And_Resolve (N, Etype (E));
- return;
- end if;
- end if;
-
- -- The type of the reference is the type of the prival, which may
- -- differ from that of the original component if it is an itype.
-
- Set_Entity (N, Prival (E));
- Set_Etype (N, Etype (Prival (E)));
- Scop := Current_Scope;
-
- -- Find entity for protected operation, which must be on scope stack.
-
- while not Is_Protected_Type (Scope (Scop)) loop
- Scop := Scope (Scop);
- end loop;
-
- Append_Elmt (N, Privals_Chain (Scop));
- end Expand_Protected_Private;
-
- ---------------------
- -- Expand_Renaming --
- ---------------------
-
- procedure Expand_Renaming (N : Node_Id) is
- E : constant Entity_Id := Entity (N);
- T : constant Entity_Id := Etype (N);
-
- begin
- Rewrite (N, New_Copy_Tree (Renamed_Object (E)));
-
- -- We mark the copy as unanalyzed, so that it is sure to be
- -- reanalyzed at the top level. This is needed in the packed
- -- case since we specifically avoided expanding packed array
- -- references when the renaming declaration was analyzed.
-
- Reset_Analyzed_Flags (N);
- Analyze_And_Resolve (N, T);
- end Expand_Renaming;
-
- ------------------
- -- Param_Entity --
- ------------------
-
- -- This would be trivial, simply a test for an identifier that was a
- -- reference to a formal, if it were not for the fact that a previous
- -- call to Expand_Entry_Parameter will have modified the reference
- -- to the identifier to be of the form
-
- -- typ!(recobj).rec.all'Constrained
-
- -- where rec is a selector whose Entry_Formal link points to the formal
-
- function Param_Entity (N : Node_Id) return Entity_Id is
- begin
- -- Simple reference case
-
- if Nkind (N) = N_Identifier then
- if Is_Formal (Entity (N)) then
- return Entity (N);
- end if;
-
- else
- if Nkind (N) = N_Explicit_Dereference then
- declare
- P : constant Node_Id := Prefix (N);
- S : Node_Id;
-
- begin
- if Nkind (P) = N_Selected_Component then
- S := Selector_Name (P);
-
- if Present (Entry_Formal (Entity (S))) then
- return Entry_Formal (Entity (S));
- end if;
- end if;
- end;
- end if;
- end if;
-
- return (Empty);
- end Param_Entity;
-
-end Exp_Ch2;
projects / msp430-gcc.git / blobdiff