-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2005, 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- --
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Cat; use Sem_Cat;
+with Sem_Ch3; use Sem_Ch3;
with Sem_Ch13; use Sem_Ch13;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Sinfo; use Sinfo;
-with Sinfo.CN; use Sinfo.CN;
with Snames; use Snames;
with Stand; use Stand;
with Targparm; use Targparm;
-- for created object. If context is an access parameter, create a
-- local access type to have a usable finalization list.
+ function Has_Inferable_Discriminants (N : Node_Id) return Boolean;
+ -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
+ -- discriminants if it has a constrained nominal type, unless the object
+ -- is a component of an enclosing Unchecked_Union object that is subject
+ -- to a per-object constraint and the enclosing object lacks inferable
+ -- discriminants.
+ --
+ -- An expression of an Unchecked_Union type has inferable discriminants
+ -- if it is either a name of an object with inferable discriminants or a
+ -- qualified expression whose subtype mark denotes a constrained subtype.
+
procedure Insert_Dereference_Action (N : Node_Id);
-- N is an expression whose type is an access. When the type of the
-- associated storage pool is derived from Checked_Pool, generate a
if Kind = N_Op_Not then
if Nkind (Op1) in N_Binary_Op then
- -- Use negated version of the binary operators.
+ -- Use negated version of the binary operators
if Nkind (Op1) = N_Op_And then
Proc_Name := RTE (RE_Vector_Nand);
if Controlled_Type (T)
and then Ekind (PtrT) = E_Anonymous_Access_Type
then
- -- Create local finalization list for access parameter.
+ -- Create local finalization list for access parameter
Flist := Get_Allocator_Final_List (N, Base_Type (T), PtrT);
end if;
Make_Selected_Component (Loc,
Prefix => New_Reference_To (Temp, Loc),
Selector_Name =>
- New_Reference_To (Tag_Component (T), Loc)),
+ New_Reference_To (First_Tag_Component (T), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
- New_Reference_To (Access_Disp_Table (T), Loc)));
+ New_Reference_To
+ (Elists.Node (First_Elmt (Access_Disp_Table (T))),
+ Loc)));
-- The previous assignment has to be done in any case
Make_Selected_Component (Loc,
Prefix => Ref,
Selector_Name =>
- New_Reference_To (Tag_Component (Utyp), Loc)),
+ New_Reference_To (First_Tag_Component (Utyp), Loc)),
Expression =>
Unchecked_Convert_To (RTE (RE_Tag),
New_Reference_To (
- Access_Disp_Table (Utyp), Loc)));
+ Elists.Node (First_Elmt (Access_Disp_Table (Utyp))),
+ Loc)));
Set_Assignment_OK (Name (Tag_Assign));
Insert_Action (N, Tag_Assign);
-- Normal case, not a secondary stack allocation
else
- Flist := Find_Final_List (PtrT);
+ if Controlled_Type (T)
+ and then Ekind (PtrT) = E_Anonymous_Access_Type
+ then
+ -- Create local finalization list for access parameter
+
+ Flist :=
+ Get_Allocator_Final_List (N, Base_Type (T), PtrT);
+ else
+ Flist := Find_Final_List (PtrT);
+ end if;
+
Attach := Make_Integer_Literal (Loc, 2);
end if;
(Arr : Entity_Id;
Nam : Name_Id;
Num : Int) return Node_Id;
- -- This builds the attribute reference Arr'Nam (Expr).
+ -- This builds the attribute reference Arr'Nam (Expr)
function Component_Equality (Typ : Entity_Id) return Node_Id;
-- Create one statement to compare corresponding components,
Test := Expand_Composite_Equality
(Nod, Component_Type (Typ), L, R, Decls);
- return
- Make_Implicit_If_Statement (Nod,
- Condition => Make_Op_Not (Loc, Right_Opnd => Test),
- Then_Statements => New_List (
- Make_Return_Statement (Loc,
- Expression => New_Occurrence_Of (Standard_False, Loc))));
+ -- If some (sub)component is an unchecked_union, the whole operation
+ -- will raise program error.
+
+ if Nkind (Test) = N_Raise_Program_Error then
+
+ -- This node is going to be inserted at a location where a
+ -- statement is expected: clear its Etype so analysis will
+ -- set it to the expected Standard_Void_Type.
+
+ Set_Etype (Test, Empty);
+ return Test;
+
+ else
+ return
+ Make_Implicit_If_Statement (Nod,
+ Condition => Make_Op_Not (Loc, Right_Opnd => Test),
+ Then_Statements => New_List (
+ Make_Return_Statement (Loc,
+ Expression => New_Occurrence_Of (Standard_False, Loc))));
+ end if;
end Component_Equality;
------------------
Handle_One_Dimension (N + 1, Next_Index (Index)));
if Need_Separate_Indexes then
- -- Generate guard for loop, followed by increments of indices.
+
+ -- Generate guard for loop, followed by increments of indices
Append_To (Stm_List,
Make_Exit_Statement (Loc,
Expressions => New_List (New_Reference_To (Bn, Loc)))));
end if;
- -- If separate indexes, we need a declare block for An and Bn,
- -- and a loop without an iteration scheme.
+ -- If separate indexes, we need a declare block for An and Bn, and a
+ -- loop without an iteration scheme.
if Need_Separate_Indexes then
Loop_Stm :=
Typ : constant Entity_Id := Etype (N);
begin
- if Is_Bit_Packed_Array (Typ) then
+ -- Special case of bit packed array where both operands are known
+ -- to be properly aligned. In this case we use an efficient run time
+ -- routine to carry out the operation (see System.Bit_Ops).
+
+ if Is_Bit_Packed_Array (Typ)
+ and then not Is_Possibly_Unaligned_Object (Left_Opnd (N))
+ and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
+ then
Expand_Packed_Boolean_Operator (N);
+ return;
+ end if;
- else
- -- For the normal non-packed case, the general expansion is
- -- to build a function for carrying out the comparison (using
- -- Make_Boolean_Array_Op) and then inserting it into the tree.
- -- The original operator node is then rewritten as a call to
- -- this function.
+ -- For the normal non-packed case, the general expansion is to build
+ -- function for carrying out the comparison (use Make_Boolean_Array_Op)
+ -- and then inserting it into the tree. The original operator node is
+ -- then rewritten as a call to this function. We also use this in the
+ -- packed case if either operand is a possibly unaligned object.
- declare
- Loc : constant Source_Ptr := Sloc (N);
- L : constant Node_Id := Relocate_Node (Left_Opnd (N));
- R : constant Node_Id := Relocate_Node (Right_Opnd (N));
- Func_Body : Node_Id;
- Func_Name : Entity_Id;
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ L : constant Node_Id := Relocate_Node (Left_Opnd (N));
+ R : constant Node_Id := Relocate_Node (Right_Opnd (N));
+ Func_Body : Node_Id;
+ Func_Name : Entity_Id;
- begin
- Convert_To_Actual_Subtype (L);
- Convert_To_Actual_Subtype (R);
- Ensure_Defined (Etype (L), N);
- Ensure_Defined (Etype (R), N);
- Apply_Length_Check (R, Etype (L));
-
- if Nkind (Parent (N)) = N_Assignment_Statement
- and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
- then
- Build_Boolean_Array_Proc_Call (Parent (N), L, R);
+ begin
+ Convert_To_Actual_Subtype (L);
+ Convert_To_Actual_Subtype (R);
+ Ensure_Defined (Etype (L), N);
+ Ensure_Defined (Etype (R), N);
+ Apply_Length_Check (R, Etype (L));
+
+ if Nkind (Parent (N)) = N_Assignment_Statement
+ and then Safe_In_Place_Array_Op (Name (Parent (N)), L, R)
+ then
+ Build_Boolean_Array_Proc_Call (Parent (N), L, R);
- elsif Nkind (Parent (N)) = N_Op_Not
- and then Nkind (N) = N_Op_And
- and then
- Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
- then
- return;
- else
+ elsif Nkind (Parent (N)) = N_Op_Not
+ and then Nkind (N) = N_Op_And
+ and then
+ Safe_In_Place_Array_Op (Name (Parent (Parent (N))), L, R)
+ then
+ return;
+ else
- Func_Body := Make_Boolean_Array_Op (Etype (L), N);
- Func_Name := Defining_Unit_Name (Specification (Func_Body));
- Insert_Action (N, Func_Body);
+ Func_Body := Make_Boolean_Array_Op (Etype (L), N);
+ Func_Name := Defining_Unit_Name (Specification (Func_Body));
+ Insert_Action (N, Func_Body);
- -- Now rewrite the expression with a call
+ -- Now rewrite the expression with a call
- Rewrite (N,
- Make_Function_Call (Loc,
- Name => New_Reference_To (Func_Name, Loc),
- Parameter_Associations =>
- New_List
- (L, Make_Type_Conversion
- (Loc, New_Reference_To (Etype (L), Loc), R))));
+ Rewrite (N,
+ Make_Function_Call (Loc,
+ Name => New_Reference_To (Func_Name, Loc),
+ Parameter_Associations =>
+ New_List (
+ L,
+ Make_Type_Conversion
+ (Loc, New_Reference_To (Etype (L), Loc), R))));
- Analyze_And_Resolve (N, Typ);
- end if;
- end;
- end if;
+ Analyze_And_Resolve (N, Typ);
+ end if;
+ end;
end Expand_Boolean_Operator;
-------------------------------
end;
else
+ -- Comparison between Unchecked_Union components
+
+ if Is_Unchecked_Union (Full_Type) then
+ declare
+ Lhs_Type : Node_Id := Full_Type;
+ Rhs_Type : Node_Id := Full_Type;
+ Lhs_Discr_Val : Node_Id;
+ Rhs_Discr_Val : Node_Id;
+
+ begin
+ -- Lhs subtype
+
+ if Nkind (Lhs) = N_Selected_Component then
+ Lhs_Type := Etype (Entity (Selector_Name (Lhs)));
+ end if;
+
+ -- Rhs subtype
+
+ if Nkind (Rhs) = N_Selected_Component then
+ Rhs_Type := Etype (Entity (Selector_Name (Rhs)));
+ end if;
+
+ -- Lhs of the composite equality
+
+ if Is_Constrained (Lhs_Type) then
+
+ -- Since the enclosing record can never be an
+ -- Unchecked_Union (this code is executed for records
+ -- that do not have variants), we may reference its
+ -- discriminant(s).
+
+ if Nkind (Lhs) = N_Selected_Component
+ and then Has_Per_Object_Constraint (
+ Entity (Selector_Name (Lhs)))
+ then
+ Lhs_Discr_Val :=
+ Make_Selected_Component (Loc,
+ Prefix => Prefix (Lhs),
+ Selector_Name =>
+ New_Copy (
+ Get_Discriminant_Value (
+ First_Discriminant (Lhs_Type),
+ Lhs_Type,
+ Stored_Constraint (Lhs_Type))));
+
+ else
+ Lhs_Discr_Val := New_Copy (
+ Get_Discriminant_Value (
+ First_Discriminant (Lhs_Type),
+ Lhs_Type,
+ Stored_Constraint (Lhs_Type)));
+
+ end if;
+ else
+ -- It is not possible to infer the discriminant since
+ -- the subtype is not constrained.
+
+ return
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction);
+ end if;
+
+ -- Rhs of the composite equality
+
+ if Is_Constrained (Rhs_Type) then
+ if Nkind (Rhs) = N_Selected_Component
+ and then Has_Per_Object_Constraint (
+ Entity (Selector_Name (Rhs)))
+ then
+ Rhs_Discr_Val :=
+ Make_Selected_Component (Loc,
+ Prefix => Prefix (Rhs),
+ Selector_Name =>
+ New_Copy (
+ Get_Discriminant_Value (
+ First_Discriminant (Rhs_Type),
+ Rhs_Type,
+ Stored_Constraint (Rhs_Type))));
+
+ else
+ Rhs_Discr_Val := New_Copy (
+ Get_Discriminant_Value (
+ First_Discriminant (Rhs_Type),
+ Rhs_Type,
+ Stored_Constraint (Rhs_Type)));
+
+ end if;
+ else
+ return
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction);
+ end if;
+
+ -- Call the TSS equality function with the inferred
+ -- discriminant values.
+
+ return
+ Make_Function_Call (Loc,
+ Name => New_Reference_To (Eq_Op, Loc),
+ Parameter_Associations => New_List (
+ Lhs,
+ Rhs,
+ Lhs_Discr_Val,
+ Rhs_Discr_Val));
+ end;
+ end if;
+
+ -- Shouldn't this be an else, we can't fall through
+ -- the above IF, right???
+
return
Make_Function_Call (Loc,
Name => New_Reference_To (Eq_Op, Loc),
-- end loop;
-- end if;
- -- ...
+ -- . . .
-- if Sn'Length /= 0 then
-- P := Sn'First;
-- L := Si'First; otherwise (where I is the input param given)
function H return Node_Id;
- -- Builds reference to identifier H.
+ -- Builds reference to identifier H
function Ind_Val (E : Node_Id) return Node_Id;
-- Builds expression Ind_Typ'Val (E);
function L return Node_Id;
- -- Builds reference to identifier L.
+ -- Builds reference to identifier L
function L_Pos return Node_Id;
- -- Builds expression Integer_Type'(Ind_Typ'Pos (L)).
- -- We qualify the expression to avoid universal_integer computations
- -- whenever possible, in the expression for the upper bound H.
+ -- Builds expression Integer_Type'(Ind_Typ'Pos (L)). We qualify the
+ -- expression to avoid universal_integer computations whenever possible,
+ -- in the expression for the upper bound H.
function L_Succ return Node_Id;
- -- Builds expression Ind_Typ'Succ (L).
+ -- Builds expression Ind_Typ'Succ (L)
function One return Node_Id;
- -- Builds integer literal one.
+ -- Builds integer literal one
function P return Node_Id;
- -- Builds reference to identifier P.
+ -- Builds reference to identifier P
function P_Succ return Node_Id;
- -- Builds expression Ind_Typ'Succ (P).
+ -- Builds expression Ind_Typ'Succ (P)
function R return Node_Id;
- -- Builds reference to identifier R.
+ -- Builds reference to identifier R
function S (I : Nat) return Node_Id;
- -- Builds reference to identifier Si, where I is the value given.
+ -- Builds reference to identifier Si, where I is the value given
function S_First (I : Nat) return Node_Id;
- -- Builds expression Si'First, where I is the value given.
+ -- Builds expression Si'First, where I is the value given
function S_Last (I : Nat) return Node_Id;
- -- Builds expression Si'Last, where I is the value given.
+ -- Builds expression Si'Last, where I is the value given
function S_Length (I : Nat) return Node_Id;
- -- Builds expression Si'Length, where I is the value given.
+ -- Builds expression Si'Length, where I is the value given
function S_Length_Test (I : Nat) return Node_Id;
- -- Builds expression Si'Length /= 0, where I is the value given.
+ -- Builds expression Si'Length /= 0, where I is the value given
-------------------
-- Copy_Into_R_S --
-- Cnn := else-expr
-- end if;
- -- and replace the conditional expression by a reference to Cnn.
+ -- and replace the conditional expression by a reference to Cnn
if Present (Then_Actions (N)) or else Present (Else_Actions (N)) then
Cnn := Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
Prefix => New_Reference_To (Typ, Loc))));
Analyze_And_Resolve (N, Rtyp);
return;
+
+ -- Ada 2005 (AI-216): Program_Error is raised when evaluating
+ -- a membership test if the subtype mark denotes a constrained
+ -- Unchecked_Union subtype and the expression lacks inferable
+ -- discriminants.
+
+ elsif Is_Unchecked_Union (Base_Type (Typ))
+ and then Is_Constrained (Typ)
+ and then not Has_Inferable_Discriminants (Lop)
+ then
+ Insert_Action (N,
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction));
+
+ -- Prevent Gigi from generating incorrect code by rewriting
+ -- the test as a standard False.
+
+ Rewrite (N,
+ New_Occurrence_Of (Standard_False, Loc));
+
+ return;
end if;
-- Here we have a non-scalar type
-- was necessary, but it cleans up the code to do it all the time.
if Is_Access_Type (T) then
- Rewrite (P,
- Make_Explicit_Dereference (Sloc (N),
- Prefix => Relocate_Node (P)));
+ Insert_Explicit_Dereference (P);
Analyze_And_Resolve (P, Designated_Type (T));
end if;
-- build and analyze call, adding conversions if the operation is
-- inherited.
+ function Has_Unconstrained_UU_Component (Typ : Node_Id) return Boolean;
+ -- Determines whether a type has a subcompoment of an unconstrained
+ -- Unchecked_Union subtype. Typ is a record type.
+
-------------------------
-- Build_Equality_Call --
-------------------------
R_Exp := OK_Convert_To (Op_Type, R_Exp);
end if;
- Rewrite (N,
- Make_Function_Call (Loc,
- Name => New_Reference_To (Eq, Loc),
- Parameter_Associations => New_List (L_Exp, R_Exp)));
+ -- If we have an Unchecked_Union, we need to add the inferred
+ -- discriminant values as actuals in the function call. At this
+ -- point, the expansion has determined that both operands have
+ -- inferable discriminants.
+
+ if Is_Unchecked_Union (Op_Type) then
+ declare
+ Lhs_Type : constant Node_Id := Etype (L_Exp);
+ Rhs_Type : constant Node_Id := Etype (R_Exp);
+ Lhs_Discr_Val : Node_Id;
+ Rhs_Discr_Val : Node_Id;
+
+ begin
+ -- Per-object constrained selected components require special
+ -- attention. If the enclosing scope of the component is an
+ -- Unchecked_Union, we can not reference its discriminants
+ -- directly. This is why we use the two extra parameters of
+ -- the equality function of the enclosing Unchecked_Union.
+
+ -- type UU_Type (Discr : Integer := 0) is
+ -- . . .
+ -- end record;
+ -- pragma Unchecked_Union (UU_Type);
+
+ -- 1. Unchecked_Union enclosing record:
+
+ -- type Enclosing_UU_Type (Discr : Integer := 0) is record
+ -- . . .
+ -- Comp : UU_Type (Discr);
+ -- . . .
+ -- end Enclosing_UU_Type;
+ -- pragma Unchecked_Union (Enclosing_UU_Type);
+
+ -- Obj1 : Enclosing_UU_Type;
+ -- Obj2 : Enclosing_UU_Type (1);
+
+ -- [. . .] Obj1 = Obj2 [. . .]
+
+ -- Generated code:
+
+ -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
+
+ -- A and B are the formal parameters of the equality function
+ -- of Enclosing_UU_Type. The function always has two extra
+ -- formals to capture the inferred discriminant values.
+
+ -- 2. Non-Unchecked_Union enclosing record:
+
+ -- type
+ -- Enclosing_Non_UU_Type (Discr : Integer := 0)
+ -- is record
+ -- . . .
+ -- Comp : UU_Type (Discr);
+ -- . . .
+ -- end Enclosing_Non_UU_Type;
+
+ -- Obj1 : Enclosing_Non_UU_Type;
+ -- Obj2 : Enclosing_Non_UU_Type (1);
+
+ -- . . . Obj1 = Obj2 . . .
+
+ -- Generated code:
+
+ -- if not (uu_typeEQ (obj1.comp, obj2.comp,
+ -- obj1.discr, obj2.discr)) then
+
+ -- In this case we can directly reference the discriminants of
+ -- the enclosing record.
+
+ -- Lhs of equality
+
+ if Nkind (Lhs) = N_Selected_Component
+ and then Has_Per_Object_Constraint
+ (Entity (Selector_Name (Lhs)))
+ then
+ -- Enclosing record is an Unchecked_Union, use formal A
+
+ if Is_Unchecked_Union (Scope
+ (Entity (Selector_Name (Lhs))))
+ then
+ Lhs_Discr_Val :=
+ Make_Identifier (Loc,
+ Chars => Name_A);
+
+ -- Enclosing record is of a non-Unchecked_Union type, it is
+ -- possible to reference the discriminant.
+
+ else
+ Lhs_Discr_Val :=
+ Make_Selected_Component (Loc,
+ Prefix => Prefix (Lhs),
+ Selector_Name =>
+ New_Copy
+ (Get_Discriminant_Value
+ (First_Discriminant (Lhs_Type),
+ Lhs_Type,
+ Stored_Constraint (Lhs_Type))));
+ end if;
+
+ -- Comment needed here ???
+
+ else
+ -- Infer the discriminant value
+
+ Lhs_Discr_Val :=
+ New_Copy
+ (Get_Discriminant_Value
+ (First_Discriminant (Lhs_Type),
+ Lhs_Type,
+ Stored_Constraint (Lhs_Type)));
+ end if;
+
+ -- Rhs of equality
+
+ if Nkind (Rhs) = N_Selected_Component
+ and then Has_Per_Object_Constraint
+ (Entity (Selector_Name (Rhs)))
+ then
+ if Is_Unchecked_Union
+ (Scope (Entity (Selector_Name (Rhs))))
+ then
+ Rhs_Discr_Val :=
+ Make_Identifier (Loc,
+ Chars => Name_B);
+
+ else
+ Rhs_Discr_Val :=
+ Make_Selected_Component (Loc,
+ Prefix => Prefix (Rhs),
+ Selector_Name =>
+ New_Copy (Get_Discriminant_Value (
+ First_Discriminant (Rhs_Type),
+ Rhs_Type,
+ Stored_Constraint (Rhs_Type))));
+
+ end if;
+ else
+ Rhs_Discr_Val :=
+ New_Copy (Get_Discriminant_Value (
+ First_Discriminant (Rhs_Type),
+ Rhs_Type,
+ Stored_Constraint (Rhs_Type)));
+
+ end if;
+
+ Rewrite (N,
+ Make_Function_Call (Loc,
+ Name => New_Reference_To (Eq, Loc),
+ Parameter_Associations => New_List (
+ L_Exp,
+ R_Exp,
+ Lhs_Discr_Val,
+ Rhs_Discr_Val)));
+ end;
+
+ -- Normal case, not an unchecked union
+
+ else
+ Rewrite (N,
+ Make_Function_Call (Loc,
+ Name => New_Reference_To (Eq, Loc),
+ Parameter_Associations => New_List (L_Exp, R_Exp)));
+ end if;
Analyze_And_Resolve (N, Standard_Boolean, Suppress => All_Checks);
end Build_Equality_Call;
+ ------------------------------------
+ -- Has_Unconstrained_UU_Component --
+ ------------------------------------
+
+ function Has_Unconstrained_UU_Component
+ (Typ : Node_Id) return Boolean
+ is
+ Tdef : constant Node_Id :=
+ Type_Definition (Declaration_Node (Base_Type (Typ)));
+ Clist : Node_Id;
+ Vpart : Node_Id;
+
+ function Component_Is_Unconstrained_UU
+ (Comp : Node_Id) return Boolean;
+ -- Determines whether the subtype of the component is an
+ -- unconstrained Unchecked_Union.
+
+ function Variant_Is_Unconstrained_UU
+ (Variant : Node_Id) return Boolean;
+ -- Determines whether a component of the variant has an unconstrained
+ -- Unchecked_Union subtype.
+
+ -----------------------------------
+ -- Component_Is_Unconstrained_UU --
+ -----------------------------------
+
+ function Component_Is_Unconstrained_UU
+ (Comp : Node_Id) return Boolean
+ is
+ begin
+ if Nkind (Comp) /= N_Component_Declaration then
+ return False;
+ end if;
+
+ declare
+ Sindic : constant Node_Id :=
+ Subtype_Indication (Component_Definition (Comp));
+
+ begin
+ -- Unconstrained nominal type. In the case of a constraint
+ -- present, the node kind would have been N_Subtype_Indication.
+
+ if Nkind (Sindic) = N_Identifier then
+ return Is_Unchecked_Union (Base_Type (Etype (Sindic)));
+ end if;
+
+ return False;
+ end;
+ end Component_Is_Unconstrained_UU;
+
+ ---------------------------------
+ -- Variant_Is_Unconstrained_UU --
+ ---------------------------------
+
+ function Variant_Is_Unconstrained_UU
+ (Variant : Node_Id) return Boolean
+ is
+ Clist : constant Node_Id := Component_List (Variant);
+
+ begin
+ if Is_Empty_List (Component_Items (Clist)) then
+ return False;
+ end if;
+
+ declare
+ Comp : Node_Id := First (Component_Items (Clist));
+
+ begin
+ while Present (Comp) loop
+
+ -- One component is sufficent
+
+ if Component_Is_Unconstrained_UU (Comp) then
+ return True;
+ end if;
+
+ Next (Comp);
+ end loop;
+ end;
+
+ -- None of the components withing the variant were of
+ -- unconstrained Unchecked_Union type.
+
+ return False;
+ end Variant_Is_Unconstrained_UU;
+
+ -- Start of processing for Has_Unconstrained_UU_Component
+
+ begin
+ if Null_Present (Tdef) then
+ return False;
+ end if;
+
+ Clist := Component_List (Tdef);
+ Vpart := Variant_Part (Clist);
+
+ -- Inspect available components
+
+ if Present (Component_Items (Clist)) then
+ declare
+ Comp : Node_Id := First (Component_Items (Clist));
+
+ begin
+ while Present (Comp) loop
+
+ -- One component is sufficent
+
+ if Component_Is_Unconstrained_UU (Comp) then
+ return True;
+ end if;
+
+ Next (Comp);
+ end loop;
+ end;
+ end if;
+
+ -- Inspect available components withing variants
+
+ if Present (Vpart) then
+ declare
+ Variant : Node_Id := First (Variants (Vpart));
+
+ begin
+ while Present (Variant) loop
+
+ -- One component within a variant is sufficent
+
+ if Variant_Is_Unconstrained_UU (Variant) then
+ return True;
+ end if;
+
+ Next (Variant);
+ end loop;
+ end;
+ end if;
+
+ -- Neither the available components, nor the components inside the
+ -- variant parts were of an unconstrained Unchecked_Union subtype.
+
+ return False;
+ end Has_Unconstrained_UU_Component;
+
-- Start of processing for Expand_N_Op_Eq
begin
Force_Validity_Checks := Save_Force_Validity_Checks;
end;
- -- Packed case
+ -- Packed case where both operands are known aligned
- elsif Is_Bit_Packed_Array (Typl) then
+ elsif Is_Bit_Packed_Array (Typl)
+ and then not Is_Possibly_Unaligned_Object (Lhs)
+ and then not Is_Possibly_Unaligned_Object (Rhs)
+ then
Expand_Packed_Eq (N);
- -- For non-floating-point elementary types, the primitive equality
- -- always applies, and block-bit comparison is fine. Floating-point
- -- is an exception because of negative zeroes.
+ -- Where the component type is elementary we can use a block bit
+ -- comparison (if supported on the target) exception in the case
+ -- of floating-point (negative zero issues require element by
+ -- element comparison), and atomic types (where we must be sure
+ -- to load elements independently) and possibly unaligned arrays.
elsif Is_Elementary_Type (Component_Type (Typl))
and then not Is_Floating_Point_Type (Component_Type (Typl))
+ and then not Is_Atomic (Component_Type (Typl))
+ and then not Is_Possibly_Unaligned_Object (Lhs)
+ and then not Is_Possibly_Unaligned_Object (Rhs)
and then Support_Composite_Compare_On_Target
then
null;
end if;
Prim := First_Elmt (Primitive_Operations (Typl));
-
while Present (Prim) loop
exit when Chars (Node (Prim)) = Name_Op_Eq
and then Etype (First_Formal (Node (Prim))) =
Build_Equality_Call (Op_Name);
+ -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
+ -- predefined equality operator for a type which has a subcomponent
+ -- of an Unchecked_Union type whose nominal subtype is unconstrained.
+
+ elsif Has_Unconstrained_UU_Component (Typl) then
+ Insert_Action (N,
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction));
+
+ -- Prevent Gigi from generating incorrect code by rewriting the
+ -- equality as a standard False.
+
+ Rewrite (N,
+ New_Occurrence_Of (Standard_False, Loc));
+
+ elsif Is_Unchecked_Union (Typl) then
+
+ -- If we can infer the discriminants of the operands, we make a
+ -- call to the TSS equality function.
+
+ if Has_Inferable_Discriminants (Lhs)
+ and then
+ Has_Inferable_Discriminants (Rhs)
+ then
+ Build_Equality_Call
+ (TSS (Root_Type (Typl), TSS_Composite_Equality));
+
+ else
+ -- Ada 2005 (AI-216): Program_Error is raised when evaluating
+ -- the predefined equality operator for an Unchecked_Union type
+ -- if either of the operands lack inferable discriminants.
+
+ Insert_Action (N,
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction));
+
+ -- Prevent Gigi from generating incorrect code by rewriting
+ -- the equality as a standard False.
+
+ Rewrite (N,
+ New_Occurrence_Of (Standard_False, Loc));
+
+ end if;
+
-- If a type support function is present (for complex cases), use it
elsif Present (TSS (Root_Type (Typl), TSS_Composite_Equality)) then
return;
end if;
- -- Case of array operand. If bit packed, handle it in Exp_Pakd
+ -- Case of array operand. If bit packed with a component size of 1,
+ -- handle it in Exp_Pakd if the operand is known to be aligned.
- if Is_Bit_Packed_Array (Typ) and then Component_Size (Typ) = 1 then
+ if Is_Bit_Packed_Array (Typ)
+ and then Component_Size (Typ) = 1
+ and then not Is_Possibly_Unaligned_Object (Right_Opnd (N))
+ then
Expand_Packed_Not (N);
return;
end if;
Build_Boolean_Array_Proc_Call (Parent (N), Opnd, Empty);
return;
- -- Special case the negation of a binary operation.
+ -- Special case the negation of a binary operation
elsif (Nkind (Opnd) = N_Op_And
or else Nkind (Opnd) = N_Op_Or
if N = Op1
and then Nkind (Op2) = N_Op_Not
then
- -- (not A) op (not B) can be reduced to a single call.
+ -- (not A) op (not B) can be reduced to a single call
return;
elsif N = Op2
and then Nkind (Parent (N)) = N_Op_Xor
then
- -- A xor (not B) can also be special-cased.
+ -- A xor (not B) can also be special-cased
return;
end if;
elsif Nkind (Parent (N)) = N_Case_Statement
and then Etype (Node (Dcon)) /= Etype (Disc)
then
- -- RBKD is suspicious of the following code. The
- -- call to New_Copy instead of New_Copy_Tree is
- -- suspicious, and the call to Analyze instead
- -- of Analyze_And_Resolve is also suspicious ???
-
- -- Wouldn't it be good enough to do a perfectly
- -- normal Analyze_And_Resolve call using the
- -- subtype of the discriminant here???
-
Rewrite (N,
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Occurrence_Of (Etype (Disc), Loc),
Expression =>
- New_Copy (Node (Dcon))));
- Analyze (N);
+ New_Copy_Tree (Node (Dcon))));
+ Analyze_And_Resolve (N, Etype (Disc));
-- In case that comes out as a static expression,
-- reset it (a selected component is never static).
return;
-- Otherwise we can just copy the constraint, but the
- -- result is certainly not static!
-
- -- Again the New_Copy here and the failure to even
- -- to an analyze call is uneasy ???
+ -- result is certainly not static! In some cases the
+ -- discriminant constraint has been analyzed in the
+ -- context of the original subtype indication, but for
+ -- itypes the constraint might not have been analyzed
+ -- yet, and this must be done now.
else
- Rewrite (N, New_Copy (Node (Dcon)));
+ Rewrite (N, New_Copy_Tree (Node (Dcon)));
+ Analyze_And_Resolve (N);
Set_Is_Static_Expression (N, False);
return;
end if;
Ptp : Entity_Id := Etype (Pfx);
function Is_Procedure_Actual (N : Node_Id) return Boolean;
- -- Check whether context is a procedure call, in which case
- -- expansion of a bit-packed slice is deferred until the call
- -- itself is expanded.
+ -- Check whether the argument is an actual for a procedure call,
+ -- in which case the expansion of a bit-packed slice is deferred
+ -- until the call itself is expanded. The reason this is required
+ -- is that we might have an IN OUT or OUT parameter, and the copy out
+ -- is essential, and that copy out would be missed if we created a
+ -- temporary here in Expand_N_Slice. Note that we don't bother
+ -- to test specifically for an IN OUT or OUT mode parameter, since it
+ -- is a bit tricky to do, and it is harmless to defer expansion
+ -- in the IN case, since the call processing will still generate the
+ -- appropriate copy in operation, which will take care of the slice.
procedure Make_Temporary;
-- Create a named variable for the value of the slice, in
Par : Node_Id := Parent (N);
begin
- while Present (Par)
- and then Nkind (Par) not in N_Statement_Other_Than_Procedure_Call
loop
+ -- If our parent is a procedure call we can return
+
if Nkind (Par) = N_Procedure_Call_Statement then
return True;
- elsif Nkind (Par) = N_Function_Call then
- return False;
+ -- If our parent is a type conversion, keep climbing the
+ -- tree, since a type conversion can be a procedure actual.
+ -- Also keep climbing if parameter association or a qualified
+ -- expression, since these are additional cases that do can
+ -- appear on procedure actuals.
- else
+ elsif Nkind (Par) = N_Type_Conversion
+ or else Nkind (Par) = N_Parameter_Association
+ or else Nkind (Par) = N_Qualified_Expression
+ then
Par := Parent (Par);
+
+ -- Any other case is not what we are looking for
+
+ else
+ return False;
end if;
end loop;
-
- return False;
end Is_Procedure_Actual;
--------------------
Condition => Cond,
Reason => CE_Tag_Check_Failed));
- Change_Conversion_To_Unchecked (N);
- Analyze_And_Resolve (N, Target_Type);
+ declare
+ Conv : Node_Id;
+ begin
+ Conv :=
+ Make_Unchecked_Type_Conversion (Loc,
+ Subtype_Mark => New_Occurrence_Of (Target_Type, Loc),
+ Expression => Relocate_Node (Expression (N)));
+ Rewrite (N, Conv);
+ Analyze_And_Resolve (N, Target_Type);
+ end;
end if;
end;
-- ityp (x)
- -- with the Float_Truncate flag set. This is clearly more efficient.
+ -- with the Float_Truncate flag set. This is clearly more efficient
if Nkind (Operand) = N_Attribute_Reference
and then Attribute_Name (Operand) = Name_Truncation
-- assignment processing.
elsif Is_Record_Type (Target_Type) then
- Handle_Changed_Representation;
+
+ -- Ada 2005 (AI-216): Program_Error is raised when converting from
+ -- a derived Unchecked_Union type to an unconstrained non-Unchecked_
+ -- Union type if the operand lacks inferable discriminants.
+
+ if Is_Derived_Type (Operand_Type)
+ and then Is_Unchecked_Union (Base_Type (Operand_Type))
+ and then not Is_Constrained (Target_Type)
+ and then not Is_Unchecked_Union (Base_Type (Target_Type))
+ and then not Has_Inferable_Discriminants (Operand)
+ then
+ -- To prevent Gigi from generating illegal code, we make a
+ -- Program_Error node, but we give it the target type of the
+ -- conversion.
+
+ declare
+ PE : constant Node_Id := Make_Raise_Program_Error (Loc,
+ Reason => PE_Unchecked_Union_Restriction);
+
+ begin
+ Set_Etype (PE, Target_Type);
+ Rewrite (N, PE);
+
+ end;
+ else
+ Handle_Changed_Representation;
+ end if;
-- Case of conversions of enumeration types
-- only if Conversion_OK is set, i.e. if the fixed-point values
-- are to be treated as integers.
- -- No other conversions should be passed to Gigi.
+ -- No other conversions should be passed to Gigi
+
+ -- Check: are these rules stated in sinfo??? if so, why restate here???
-- The only remaining step is to generate a range check if we still
-- have a type conversion at this stage and Do_Range_Check is set.
-- Start of processing for Expand_Record_Equality
begin
- -- Special processing for the unchecked union case, which will occur
- -- only in the context of tagged types and dynamic dispatching, since
- -- other cases are handled statically. We return True, but insert a
- -- raise Program_Error statement.
-
- if Is_Unchecked_Union (Typ) then
-
- -- If this is a component of an enclosing record, return the Raise
- -- statement directly.
-
- if No (Parent (Lhs)) then
- Result :=
- Make_Raise_Program_Error (Loc,
- Reason => PE_Unchecked_Union_Restriction);
- Set_Etype (Result, Standard_Boolean);
- return Result;
-
- else
- Insert_Action (Lhs,
- Make_Raise_Program_Error (Loc,
- Reason => PE_Unchecked_Union_Restriction));
- return New_Occurrence_Of (Standard_True, Loc);
- end if;
- end if;
-
-- Generates the following code: (assuming that Typ has one Discr and
-- component C2 is also a record)
declare
New_Lhs : Node_Id;
New_Rhs : Node_Id;
+ Check : Node_Id;
begin
if First_Time then
New_Rhs := New_Copy_Tree (Rhs);
end if;
- Result :=
- Make_And_Then (Loc,
- Left_Opnd => Result,
- Right_Opnd =>
- Expand_Composite_Equality (Nod, Etype (C),
- Lhs =>
- Make_Selected_Component (Loc,
- Prefix => New_Lhs,
- Selector_Name => New_Reference_To (C, Loc)),
- Rhs =>
- Make_Selected_Component (Loc,
- Prefix => New_Rhs,
- Selector_Name => New_Reference_To (C, Loc)),
- Bodies => Bodies));
+ Check :=
+ Expand_Composite_Equality (Nod, Etype (C),
+ Lhs =>
+ Make_Selected_Component (Loc,
+ Prefix => New_Lhs,
+ Selector_Name => New_Reference_To (C, Loc)),
+ Rhs =>
+ Make_Selected_Component (Loc,
+ Prefix => New_Rhs,
+ Selector_Name => New_Reference_To (C, Loc)),
+ Bodies => Bodies);
+
+ -- If some (sub)component is an unchecked_union, the whole
+ -- operation will raise program error.
+
+ if Nkind (Check) = N_Raise_Program_Error then
+ Result := Check;
+ Set_Etype (Result, Standard_Boolean);
+ exit;
+ else
+ Result :=
+ Make_And_Then (Loc,
+ Left_Opnd => Result,
+ Right_Opnd => Check);
+ end if;
end;
C := Suitable_Element (Next_Entity (C));
return Find_Final_List (Owner);
end Get_Allocator_Final_List;
+ ---------------------------------
+ -- Has_Inferable_Discriminants --
+ ---------------------------------
+
+ function Has_Inferable_Discriminants (N : Node_Id) return Boolean is
+
+ function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean;
+ -- Determines whether the left-most prefix of a selected component is a
+ -- formal parameter in a subprogram. Assumes N is a selected component.
+
+ --------------------------------
+ -- Prefix_Is_Formal_Parameter --
+ --------------------------------
+
+ function Prefix_Is_Formal_Parameter (N : Node_Id) return Boolean is
+ Sel_Comp : Node_Id := N;
+
+ begin
+ -- Move to the left-most prefix by climbing up the tree
+
+ while Present (Parent (Sel_Comp))
+ and then Nkind (Parent (Sel_Comp)) = N_Selected_Component
+ loop
+ Sel_Comp := Parent (Sel_Comp);
+ end loop;
+
+ return Ekind (Entity (Prefix (Sel_Comp))) in Formal_Kind;
+ end Prefix_Is_Formal_Parameter;
+
+ -- Start of processing for Has_Inferable_Discriminants
+
+ begin
+ -- For identifiers and indexed components, it is sufficent to have a
+ -- constrained Unchecked_Union nominal subtype.
+
+ if Nkind (N) = N_Identifier
+ or else
+ Nkind (N) = N_Indexed_Component
+ then
+ return Is_Unchecked_Union (Base_Type (Etype (N)))
+ and then
+ Is_Constrained (Etype (N));
+
+ -- For selected components, the subtype of the selector must be a
+ -- constrained Unchecked_Union. If the component is subject to a
+ -- per-object constraint, then the enclosing object must have inferable
+ -- discriminants.
+
+ elsif Nkind (N) = N_Selected_Component then
+ if Has_Per_Object_Constraint (Entity (Selector_Name (N))) then
+
+ -- A small hack. If we have a per-object constrained selected
+ -- component of a formal parameter, return True since we do not
+ -- know the actual parameter association yet.
+
+ if Prefix_Is_Formal_Parameter (N) then
+ return True;
+ end if;
+
+ -- Otherwise, check the enclosing object and the selector
+
+ return Has_Inferable_Discriminants (Prefix (N))
+ and then
+ Has_Inferable_Discriminants (Selector_Name (N));
+ end if;
+
+ -- The call to Has_Inferable_Discriminants will determine whether
+ -- the selector has a constrained Unchecked_Union nominal type.
+
+ return Has_Inferable_Discriminants (Selector_Name (N));
+
+ -- A qualified expression has inferable discriminants if its subtype
+ -- mark is a constrained Unchecked_Union subtype.
+
+ elsif Nkind (N) = N_Qualified_Expression then
+ return Is_Unchecked_Union (Subtype_Mark (N))
+ and then
+ Is_Constrained (Subtype_Mark (N));
+
+ end if;
+
+ return False;
+ end Has_Inferable_Discriminants;
+
-------------------------------
-- Insert_Dereference_Action --
-------------------------------
-- is safe. The operand can be empty in the case of negation.
function Is_Unaliased (N : Node_Id) return Boolean;
- -- Check that N is a stand-alone entity.
+ -- Check that N is a stand-alone entity
------------------
-- Is_Unaliased --
Obj_Tag :=
Make_Selected_Component (Loc,
Prefix => Relocate_Node (Left),
- Selector_Name => New_Reference_To (Tag_Component (Left_Type), Loc));
+ Selector_Name =>
+ New_Reference_To (First_Tag_Component (Left_Type), Loc));
if Is_Class_Wide_Type (Right_Type) then
return
Action => CW_Membership,
Args => New_List (
Obj_Tag,
- New_Reference_To (
- Access_Disp_Table (Root_Type (Right_Type)), Loc)));
+ New_Reference_To
+ (Node (First_Elmt
+ (Access_Disp_Table (Root_Type (Right_Type)))),
+ Loc)));
else
return
Make_Op_Eq (Loc,
Left_Opnd => Obj_Tag,
Right_Opnd =>
- New_Reference_To (Access_Disp_Table (Right_Type), Loc));
+ New_Reference_To
+ (Node (First_Elmt (Access_Disp_Table (Right_Type))), Loc));
end if;
end Tagged_Membership;
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