| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ R E S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2004, 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 Checks; use Checks; |
| with Debug; use Debug; |
| with Debug_A; use Debug_A; |
| with Einfo; use Einfo; |
| with Errout; use Errout; |
| with Expander; use Expander; |
| with Exp_Ch7; use Exp_Ch7; |
| with Exp_Tss; use Exp_Tss; |
| with Exp_Util; use Exp_Util; |
| with Freeze; use Freeze; |
| with Itypes; use Itypes; |
| with Lib; use Lib; |
| with Lib.Xref; use Lib.Xref; |
| with Namet; use Namet; |
| with Nmake; use Nmake; |
| with Nlists; use Nlists; |
| with Opt; use Opt; |
| with Output; use Output; |
| with Restrict; use Restrict; |
| with Rtsfind; use Rtsfind; |
| with Sem; use Sem; |
| with Sem_Aggr; use Sem_Aggr; |
| with Sem_Attr; use Sem_Attr; |
| with Sem_Cat; use Sem_Cat; |
| with Sem_Ch4; use Sem_Ch4; |
| with Sem_Ch6; use Sem_Ch6; |
| with Sem_Ch8; use Sem_Ch8; |
| with Sem_Disp; use Sem_Disp; |
| with Sem_Dist; use Sem_Dist; |
| with Sem_Elab; use Sem_Elab; |
| with Sem_Eval; use Sem_Eval; |
| with Sem_Intr; use Sem_Intr; |
| with Sem_Util; use Sem_Util; |
| with Sem_Type; use Sem_Type; |
| with Sem_Warn; use Sem_Warn; |
| with Sinfo; use Sinfo; |
| with Snames; use Snames; |
| with Stand; use Stand; |
| with Stringt; use Stringt; |
| with Targparm; use Targparm; |
| with Tbuild; use Tbuild; |
| with Uintp; use Uintp; |
| with Urealp; use Urealp; |
| |
| package body Sem_Res is |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| -- Second pass (top-down) type checking and overload resolution procedures |
| -- Typ is the type required by context. These procedures propagate the |
| -- type information recursively to the descendants of N. If the node |
| -- is not overloaded, its Etype is established in the first pass. If |
| -- overloaded, the Resolve routines set the correct type. For arith. |
| -- operators, the Etype is the base type of the context. |
| |
| -- Note that Resolve_Attribute is separated off in Sem_Attr |
| |
| procedure Ambiguous_Character (C : Node_Id); |
| -- Give list of candidate interpretations when a character literal cannot |
| -- be resolved. |
| |
| procedure Check_Direct_Boolean_Op (N : Node_Id); |
| -- N is a binary operator node which may possibly operate on Boolean |
| -- operands. If the operator does have Boolean operands, then a call is |
| -- made to check the restriction No_Direct_Boolean_Operators. |
| |
| procedure Check_Discriminant_Use (N : Node_Id); |
| -- Enforce the restrictions on the use of discriminants when constraining |
| -- a component of a discriminated type (record or concurrent type). |
| |
| procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id); |
| -- Given a node for an operator associated with type T, check that |
| -- the operator is visible. Operators all of whose operands are |
| -- universal must be checked for visibility during resolution |
| -- because their type is not determinable based on their operands. |
| |
| function Check_Infinite_Recursion (N : Node_Id) return Boolean; |
| -- Given a call node, N, which is known to occur immediately within the |
| -- subprogram being called, determines whether it is a detectable case of |
| -- an infinite recursion, and if so, outputs appropriate messages. Returns |
| -- True if an infinite recursion is detected, and False otherwise. |
| |
| procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id); |
| -- If the type of the object being initialized uses the secondary stack |
| -- directly or indirectly, create a transient scope for the call to the |
| -- init proc. This is because we do not create transient scopes for the |
| -- initialization of individual components within the init proc itself. |
| -- Could be optimized away perhaps? |
| |
| function Is_Predefined_Op (Nam : Entity_Id) return Boolean; |
| -- Utility to check whether the name in the call is a predefined |
| -- operator, in which case the call is made into an operator node. |
| -- An instance of an intrinsic conversion operation may be given |
| -- an operator name, but is not treated like an operator. |
| |
| procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id); |
| -- If a default expression in entry call N depends on the discriminants |
| -- of the task, it must be replaced with a reference to the discriminant |
| -- of the task being called. |
| |
| procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Call (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Null (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Range (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id); |
| procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id); |
| |
| function Operator_Kind |
| (Op_Name : Name_Id; |
| Is_Binary : Boolean) |
| return Node_Kind; |
| -- Utility to map the name of an operator into the corresponding Node. Used |
| -- by other node rewriting procedures. |
| |
| procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id); |
| -- Resolve actuals of call, and add default expressions for missing ones. |
| |
| procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id); |
| -- Called from Resolve_Call, when the prefix denotes an entry or element |
| -- of entry family. Actuals are resolved as for subprograms, and the node |
| -- is rebuilt as an entry call. Also called for protected operations. Typ |
| -- is the context type, which is used when the operation is a protected |
| -- function with no arguments, and the return value is indexed. |
| |
| procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id); |
| -- A call to a user-defined intrinsic operator is rewritten as a call |
| -- to the corresponding predefined operator, with suitable conversions. |
| |
| procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id); |
| -- Ditto, for unary operators (only arithmetic ones). |
| |
| procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id); |
| -- If an operator node resolves to a call to a user-defined operator, |
| -- rewrite the node as a function call. |
| |
| procedure Make_Call_Into_Operator |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Op_Id : Entity_Id); |
| -- Inverse transformation: if an operator is given in functional notation, |
| -- then after resolving the node, transform into an operator node, so |
| -- that operands are resolved properly. Recall that predefined operators |
| -- do not have a full signature and special resolution rules apply. |
| |
| procedure Rewrite_Renamed_Operator (N : Node_Id; Op : Entity_Id); |
| -- An operator can rename another, e.g. in an instantiation. In that |
| -- case, the proper operator node must be constructed. |
| |
| procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id); |
| -- The String_Literal_Subtype is built for all strings that are not |
| -- operands of a static concatenation operation. If the argument is |
| -- not a N_String_Literal node, then the call has no effect. |
| |
| procedure Set_Slice_Subtype (N : Node_Id); |
| -- Build subtype of array type, with the range specified by the slice |
| |
| function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id; |
| -- A universal_fixed expression in an universal context is unambiguous |
| -- if there is only one applicable fixed point type. Determining whether |
| -- there is only one requires a search over all visible entities, and |
| -- happens only in very pathological cases (see 6115-006). |
| |
| function Valid_Conversion |
| (N : Node_Id; |
| Target : Entity_Id; |
| Operand : Node_Id) |
| return Boolean; |
| -- Verify legality rules given in 4.6 (8-23). Target is the target |
| -- type of the conversion, which may be an implicit conversion of |
| -- an actual parameter to an anonymous access type (in which case |
| -- N denotes the actual parameter and N = Operand). |
| |
| ------------------------- |
| -- Ambiguous_Character -- |
| ------------------------- |
| |
| procedure Ambiguous_Character (C : Node_Id) is |
| E : Entity_Id; |
| |
| begin |
| if Nkind (C) = N_Character_Literal then |
| Error_Msg_N ("ambiguous character literal", C); |
| Error_Msg_N |
| ("\possible interpretations: Character, Wide_Character!", C); |
| |
| E := Current_Entity (C); |
| |
| if Present (E) then |
| |
| while Present (E) loop |
| Error_Msg_NE ("\possible interpretation:}!", C, Etype (E)); |
| E := Homonym (E); |
| end loop; |
| end if; |
| end if; |
| end Ambiguous_Character; |
| |
| ------------------------- |
| -- Analyze_And_Resolve -- |
| ------------------------- |
| |
| procedure Analyze_And_Resolve (N : Node_Id) is |
| begin |
| Analyze (N); |
| Resolve (N); |
| end Analyze_And_Resolve; |
| |
| procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Analyze (N); |
| Resolve (N, Typ); |
| end Analyze_And_Resolve; |
| |
| -- Version withs check(s) suppressed |
| |
| procedure Analyze_And_Resolve |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Suppress : Check_Id) |
| is |
| Scop : constant Entity_Id := Current_Scope; |
| |
| begin |
| if Suppress = All_Checks then |
| declare |
| Svg : constant Suppress_Array := Scope_Suppress; |
| |
| begin |
| Scope_Suppress := (others => True); |
| Analyze_And_Resolve (N, Typ); |
| Scope_Suppress := Svg; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress (Suppress); |
| |
| begin |
| Scope_Suppress (Suppress) := True; |
| Analyze_And_Resolve (N, Typ); |
| Scope_Suppress (Suppress) := Svg; |
| end; |
| end if; |
| |
| if Current_Scope /= Scop |
| and then Scope_Is_Transient |
| then |
| -- This can only happen if a transient scope was created |
| -- for an inner expression, which will be removed upon |
| -- completion of the analysis of an enclosing construct. |
| -- The transient scope must have the suppress status of |
| -- the enclosing environment, not of this Analyze call. |
| |
| Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress := |
| Scope_Suppress; |
| end if; |
| end Analyze_And_Resolve; |
| |
| procedure Analyze_And_Resolve |
| (N : Node_Id; |
| Suppress : Check_Id) |
| is |
| Scop : constant Entity_Id := Current_Scope; |
| |
| begin |
| if Suppress = All_Checks then |
| declare |
| Svg : constant Suppress_Array := Scope_Suppress; |
| |
| begin |
| Scope_Suppress := (others => True); |
| Analyze_And_Resolve (N); |
| Scope_Suppress := Svg; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress (Suppress); |
| |
| begin |
| Scope_Suppress (Suppress) := True; |
| Analyze_And_Resolve (N); |
| Scope_Suppress (Suppress) := Svg; |
| end; |
| end if; |
| |
| if Current_Scope /= Scop |
| and then Scope_Is_Transient |
| then |
| Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress := |
| Scope_Suppress; |
| end if; |
| end Analyze_And_Resolve; |
| |
| ----------------------------- |
| -- Check_Direct_Boolean_Op -- |
| ----------------------------- |
| |
| procedure Check_Direct_Boolean_Op (N : Node_Id) is |
| begin |
| if Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean then |
| Check_Restriction (No_Direct_Boolean_Operators, N); |
| end if; |
| end Check_Direct_Boolean_Op; |
| |
| ---------------------------- |
| -- Check_Discriminant_Use -- |
| ---------------------------- |
| |
| procedure Check_Discriminant_Use (N : Node_Id) is |
| PN : constant Node_Id := Parent (N); |
| Disc : constant Entity_Id := Entity (N); |
| P : Node_Id; |
| D : Node_Id; |
| |
| begin |
| -- Any use in a default expression is legal. |
| |
| if In_Default_Expression then |
| null; |
| |
| elsif Nkind (PN) = N_Range then |
| |
| -- Discriminant cannot be used to constrain a scalar type. |
| |
| P := Parent (PN); |
| |
| if Nkind (P) = N_Range_Constraint |
| and then Nkind (Parent (P)) = N_Subtype_Indication |
| and then Nkind (Parent (Parent (P))) = N_Component_Definition |
| then |
| Error_Msg_N ("discriminant cannot constrain scalar type", N); |
| |
| elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then |
| |
| -- The following check catches the unusual case where |
| -- a discriminant appears within an index constraint |
| -- that is part of a larger expression within a constraint |
| -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))". |
| -- For now we only check case of record components, and |
| -- note that a similar check should also apply in the |
| -- case of discriminant constraints below. ??? |
| |
| -- Note that the check for N_Subtype_Declaration below is to |
| -- detect the valid use of discriminants in the constraints of a |
| -- subtype declaration when this subtype declaration appears |
| -- inside the scope of a record type (which is syntactically |
| -- illegal, but which may be created as part of derived type |
| -- processing for records). See Sem_Ch3.Build_Derived_Record_Type |
| -- for more info. |
| |
| if Ekind (Current_Scope) = E_Record_Type |
| and then Scope (Disc) = Current_Scope |
| and then not |
| (Nkind (Parent (P)) = N_Subtype_Indication |
| and then |
| (Nkind (Parent (Parent (P))) = N_Component_Definition |
| or else |
| Nkind (Parent (Parent (P))) = N_Subtype_Declaration) |
| and then Paren_Count (N) = 0) |
| then |
| Error_Msg_N |
| ("discriminant must appear alone in component constraint", N); |
| return; |
| end if; |
| |
| -- Detect a common beginner error: |
| |
| -- type R (D : Positive := 100) is record |
| -- Name : String (1 .. D); |
| -- end record; |
| |
| -- The default value causes an object of type R to be |
| -- allocated with room for Positive'Last characters. |
| |
| declare |
| SI : Node_Id; |
| T : Entity_Id; |
| TB : Node_Id; |
| CB : Entity_Id; |
| |
| function Large_Storage_Type (T : Entity_Id) return Boolean; |
| -- Return True if type T has a large enough range that |
| -- any array whose index type covered the whole range of |
| -- the type would likely raise Storage_Error. |
| |
| ------------------------ |
| -- Large_Storage_Type -- |
| ------------------------ |
| |
| function Large_Storage_Type (T : Entity_Id) return Boolean is |
| begin |
| return |
| T = Standard_Integer |
| or else |
| T = Standard_Positive |
| or else |
| T = Standard_Natural; |
| end Large_Storage_Type; |
| |
| begin |
| -- Check that the Disc has a large range |
| |
| if not Large_Storage_Type (Etype (Disc)) then |
| goto No_Danger; |
| end if; |
| |
| -- If the enclosing type is limited, we allocate only the |
| -- default value, not the maximum, and there is no need for |
| -- a warning. |
| |
| if Is_Limited_Type (Scope (Disc)) then |
| goto No_Danger; |
| end if; |
| |
| -- Check that it is the high bound |
| |
| if N /= High_Bound (PN) |
| or else not Present (Discriminant_Default_Value (Disc)) |
| then |
| goto No_Danger; |
| end if; |
| |
| -- Check the array allows a large range at this bound. |
| -- First find the array |
| |
| SI := Parent (P); |
| |
| if Nkind (SI) /= N_Subtype_Indication then |
| goto No_Danger; |
| end if; |
| |
| T := Entity (Subtype_Mark (SI)); |
| |
| if not Is_Array_Type (T) then |
| goto No_Danger; |
| end if; |
| |
| -- Next, find the dimension |
| |
| TB := First_Index (T); |
| CB := First (Constraints (P)); |
| while True |
| and then Present (TB) |
| and then Present (CB) |
| and then CB /= PN |
| loop |
| Next_Index (TB); |
| Next (CB); |
| end loop; |
| |
| if CB /= PN then |
| goto No_Danger; |
| end if; |
| |
| -- Now, check the dimension has a large range |
| |
| if not Large_Storage_Type (Etype (TB)) then |
| goto No_Danger; |
| end if; |
| |
| -- Warn about the danger |
| |
| Error_Msg_N |
| ("creation of & object may raise Storage_Error?", |
| Scope (Disc)); |
| |
| <<No_Danger>> |
| null; |
| |
| end; |
| end if; |
| |
| -- Legal case is in index or discriminant constraint |
| |
| elsif Nkind (PN) = N_Index_Or_Discriminant_Constraint |
| or else Nkind (PN) = N_Discriminant_Association |
| then |
| if Paren_Count (N) > 0 then |
| Error_Msg_N |
| ("discriminant in constraint must appear alone", N); |
| end if; |
| |
| return; |
| |
| -- Otherwise, context is an expression. It should not be within |
| -- (i.e. a subexpression of) a constraint for a component. |
| |
| else |
| D := PN; |
| P := Parent (PN); |
| |
| while Nkind (P) /= N_Component_Declaration |
| and then Nkind (P) /= N_Subtype_Indication |
| and then Nkind (P) /= N_Entry_Declaration |
| loop |
| D := P; |
| P := Parent (P); |
| exit when No (P); |
| end loop; |
| |
| -- If the discriminant is used in an expression that is a bound |
| -- of a scalar type, an Itype is created and the bounds are attached |
| -- to its range, not to the original subtype indication. Such use |
| -- is of course a double fault. |
| |
| if (Nkind (P) = N_Subtype_Indication |
| and then |
| (Nkind (Parent (P)) = N_Component_Definition |
| or else |
| Nkind (Parent (P)) = N_Derived_Type_Definition) |
| and then D = Constraint (P)) |
| |
| -- The constraint itself may be given by a subtype indication, |
| -- rather than by a more common discrete range. |
| |
| or else (Nkind (P) = N_Subtype_Indication |
| and then |
| Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint) |
| or else Nkind (P) = N_Entry_Declaration |
| or else Nkind (D) = N_Defining_Identifier |
| then |
| Error_Msg_N |
| ("discriminant in constraint must appear alone", N); |
| end if; |
| end if; |
| end Check_Discriminant_Use; |
| |
| -------------------------------- |
| -- Check_For_Visible_Operator -- |
| -------------------------------- |
| |
| procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is |
| begin |
| if Is_Invisible_Operator (N, T) then |
| Error_Msg_NE |
| ("operator for} is not directly visible!", N, First_Subtype (T)); |
| Error_Msg_N ("use clause would make operation legal!", N); |
| end if; |
| end Check_For_Visible_Operator; |
| |
| ------------------------------ |
| -- Check_Infinite_Recursion -- |
| ------------------------------ |
| |
| function Check_Infinite_Recursion (N : Node_Id) return Boolean is |
| P : Node_Id; |
| C : Node_Id; |
| |
| function Same_Argument_List return Boolean; |
| -- Check whether list of actuals is identical to list of formals |
| -- of called function (which is also the enclosing scope). |
| |
| ------------------------ |
| -- Same_Argument_List -- |
| ------------------------ |
| |
| function Same_Argument_List return Boolean is |
| A : Node_Id; |
| F : Entity_Id; |
| Subp : Entity_Id; |
| |
| begin |
| if not Is_Entity_Name (Name (N)) then |
| return False; |
| else |
| Subp := Entity (Name (N)); |
| end if; |
| |
| F := First_Formal (Subp); |
| A := First_Actual (N); |
| |
| while Present (F) and then Present (A) loop |
| if not Is_Entity_Name (A) |
| or else Entity (A) /= F |
| then |
| return False; |
| end if; |
| |
| Next_Actual (A); |
| Next_Formal (F); |
| end loop; |
| |
| return True; |
| end Same_Argument_List; |
| |
| -- Start of processing for Check_Infinite_Recursion |
| |
| begin |
| -- Loop moving up tree, quitting if something tells us we are |
| -- definitely not in an infinite recursion situation. |
| |
| C := N; |
| loop |
| P := Parent (C); |
| exit when Nkind (P) = N_Subprogram_Body; |
| |
| if Nkind (P) = N_Or_Else or else |
| Nkind (P) = N_And_Then or else |
| Nkind (P) = N_If_Statement or else |
| Nkind (P) = N_Case_Statement |
| then |
| return False; |
| |
| elsif Nkind (P) = N_Handled_Sequence_Of_Statements |
| and then C /= First (Statements (P)) |
| then |
| -- If the call is the expression of a return statement and |
| -- the actuals are identical to the formals, it's worth a |
| -- warning. However, we skip this if there is an immediately |
| -- preceding raise statement, since the call is never executed. |
| |
| -- Furthermore, this corresponds to a common idiom: |
| |
| -- function F (L : Thing) return Boolean is |
| -- begin |
| -- raise Program_Error; |
| -- return F (L); |
| -- end F; |
| |
| -- for generating a stub function |
| |
| if Nkind (Parent (N)) = N_Return_Statement |
| and then Same_Argument_List |
| then |
| exit when not Is_List_Member (Parent (N)) |
| or else (Nkind (Prev (Parent (N))) /= N_Raise_Statement |
| and then |
| (Nkind (Prev (Parent (N))) not in N_Raise_xxx_Error |
| or else |
| Present (Condition (Prev (Parent (N)))))); |
| end if; |
| |
| return False; |
| |
| else |
| C := P; |
| end if; |
| end loop; |
| |
| Error_Msg_N ("possible infinite recursion?", N); |
| Error_Msg_N ("\Storage_Error may be raised at run time?", N); |
| |
| return True; |
| end Check_Infinite_Recursion; |
| |
| ------------------------------- |
| -- Check_Initialization_Call -- |
| ------------------------------- |
| |
| procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is |
| Typ : constant Entity_Id := Etype (First_Formal (Nam)); |
| |
| function Uses_SS (T : Entity_Id) return Boolean; |
| -- Check whether the creation of an object of the type will involve |
| -- use of the secondary stack. If T is a record type, this is true |
| -- if the expression for some component uses the secondary stack, eg. |
| -- through a call to a function that returns an unconstrained value. |
| -- False if T is controlled, because cleanups occur elsewhere. |
| |
| ------------- |
| -- Uses_SS -- |
| ------------- |
| |
| function Uses_SS (T : Entity_Id) return Boolean is |
| Comp : Entity_Id; |
| Expr : Node_Id; |
| |
| begin |
| if Is_Controlled (T) then |
| return False; |
| |
| elsif Is_Array_Type (T) then |
| return Uses_SS (Component_Type (T)); |
| |
| elsif Is_Record_Type (T) then |
| Comp := First_Component (T); |
| |
| while Present (Comp) loop |
| |
| if Ekind (Comp) = E_Component |
| and then Nkind (Parent (Comp)) = N_Component_Declaration |
| then |
| Expr := Expression (Parent (Comp)); |
| |
| -- The expression for a dynamic component may be |
| -- rewritten as a dereference. Retrieve original |
| -- call. |
| |
| if Nkind (Original_Node (Expr)) = N_Function_Call |
| and then Requires_Transient_Scope (Etype (Expr)) |
| then |
| return True; |
| |
| elsif Uses_SS (Etype (Comp)) then |
| return True; |
| end if; |
| end if; |
| |
| Next_Component (Comp); |
| end loop; |
| |
| return False; |
| |
| else |
| return False; |
| end if; |
| end Uses_SS; |
| |
| -- Start of processing for Check_Initialization_Call |
| |
| begin |
| -- Nothing to do if functions do not use the secondary stack for |
| -- returns (i.e. they use a depressed stack pointer instead). |
| |
| if Functions_Return_By_DSP_On_Target then |
| return; |
| |
| -- Otherwise establish a transient scope if the type needs it |
| |
| elsif Uses_SS (Typ) then |
| Establish_Transient_Scope (First_Actual (N), Sec_Stack => True); |
| end if; |
| end Check_Initialization_Call; |
| |
| ------------------------------ |
| -- Check_Parameterless_Call -- |
| ------------------------------ |
| |
| procedure Check_Parameterless_Call (N : Node_Id) is |
| Nam : Node_Id; |
| |
| begin |
| -- Defend against junk stuff if errors already detected |
| |
| if Total_Errors_Detected /= 0 then |
| if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then |
| return; |
| elsif Nkind (N) in N_Has_Chars |
| and then Chars (N) in Error_Name_Or_No_Name |
| then |
| return; |
| end if; |
| |
| Require_Entity (N); |
| end if; |
| |
| -- Rewrite as call if overloadable entity that is (or could be, in |
| -- the overloaded case) a function call. If we know for sure that |
| -- the entity is an enumeration literal, we do not rewrite it. |
| |
| if (Is_Entity_Name (N) |
| and then Is_Overloadable (Entity (N)) |
| and then (Ekind (Entity (N)) /= E_Enumeration_Literal |
| or else Is_Overloaded (N))) |
| |
| -- Rewrite as call if it is an explicit deference of an expression of |
| -- a subprogram access type, and the suprogram type is not that of a |
| -- procedure or entry. |
| |
| or else |
| (Nkind (N) = N_Explicit_Dereference |
| and then Ekind (Etype (N)) = E_Subprogram_Type |
| and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type) |
| |
| -- Rewrite as call if it is a selected component which is a function, |
| -- this is the case of a call to a protected function (which may be |
| -- overloaded with other protected operations). |
| |
| or else |
| (Nkind (N) = N_Selected_Component |
| and then (Ekind (Entity (Selector_Name (N))) = E_Function |
| or else |
| ((Ekind (Entity (Selector_Name (N))) = E_Entry |
| or else |
| Ekind (Entity (Selector_Name (N))) = E_Procedure) |
| and then Is_Overloaded (Selector_Name (N))))) |
| |
| -- If one of the above three conditions is met, rewrite as call. |
| -- Apply the rewriting only once. |
| |
| then |
| if Nkind (Parent (N)) /= N_Function_Call |
| or else N /= Name (Parent (N)) |
| then |
| Nam := New_Copy (N); |
| |
| -- If overloaded, overload set belongs to new copy. |
| |
| Save_Interps (N, Nam); |
| |
| -- Change node to parameterless function call (note that the |
| -- Parameter_Associations associations field is left set to Empty, |
| -- its normal default value since there are no parameters) |
| |
| Change_Node (N, N_Function_Call); |
| Set_Name (N, Nam); |
| Set_Sloc (N, Sloc (Nam)); |
| Analyze_Call (N); |
| end if; |
| |
| elsif Nkind (N) = N_Parameter_Association then |
| Check_Parameterless_Call (Explicit_Actual_Parameter (N)); |
| end if; |
| end Check_Parameterless_Call; |
| |
| ---------------------- |
| -- Is_Predefined_Op -- |
| ---------------------- |
| |
| function Is_Predefined_Op (Nam : Entity_Id) return Boolean is |
| begin |
| return Is_Intrinsic_Subprogram (Nam) |
| and then not Is_Generic_Instance (Nam) |
| and then Chars (Nam) in Any_Operator_Name |
| and then (No (Alias (Nam)) |
| or else Is_Predefined_Op (Alias (Nam))); |
| end Is_Predefined_Op; |
| |
| ----------------------------- |
| -- Make_Call_Into_Operator -- |
| ----------------------------- |
| |
| procedure Make_Call_Into_Operator |
| (N : Node_Id; |
| Typ : Entity_Id; |
| Op_Id : Entity_Id) |
| is |
| Op_Name : constant Name_Id := Chars (Op_Id); |
| Act1 : Node_Id := First_Actual (N); |
| Act2 : Node_Id := Next_Actual (Act1); |
| Error : Boolean := False; |
| Is_Binary : constant Boolean := Present (Act2); |
| Op_Node : Node_Id; |
| Opnd_Type : Entity_Id; |
| Orig_Type : Entity_Id := Empty; |
| Pack : Entity_Id; |
| |
| type Kind_Test is access function (E : Entity_Id) return Boolean; |
| |
| function Is_Definite_Access_Type (E : Entity_Id) return Boolean; |
| -- Determine whether E is an access type declared by an access decla- |
| -- ration, and not an (anonymous) allocator type. |
| |
| function Operand_Type_In_Scope (S : Entity_Id) return Boolean; |
| -- If the operand is not universal, and the operator is given by a |
| -- expanded name, verify that the operand has an interpretation with |
| -- a type defined in the given scope of the operator. |
| |
| function Type_In_P (Test : Kind_Test) return Entity_Id; |
| -- Find a type of the given class in the package Pack that contains |
| -- the operator. |
| |
| ----------------------------- |
| -- Is_Definite_Access_Type -- |
| ----------------------------- |
| |
| function Is_Definite_Access_Type (E : Entity_Id) return Boolean is |
| Btyp : constant Entity_Id := Base_Type (E); |
| begin |
| return Ekind (Btyp) = E_Access_Type |
| or else (Ekind (Btyp) = E_Access_Subprogram_Type |
| and then Comes_From_Source (Btyp)); |
| end Is_Definite_Access_Type; |
| |
| --------------------------- |
| -- Operand_Type_In_Scope -- |
| --------------------------- |
| |
| function Operand_Type_In_Scope (S : Entity_Id) return Boolean is |
| Nod : constant Node_Id := Right_Opnd (Op_Node); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| if not Is_Overloaded (Nod) then |
| return Scope (Base_Type (Etype (Nod))) = S; |
| |
| else |
| Get_First_Interp (Nod, I, It); |
| |
| while Present (It.Typ) loop |
| |
| if Scope (Base_Type (It.Typ)) = S then |
| return True; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| return False; |
| end if; |
| end Operand_Type_In_Scope; |
| |
| --------------- |
| -- Type_In_P -- |
| --------------- |
| |
| function Type_In_P (Test : Kind_Test) return Entity_Id is |
| E : Entity_Id; |
| |
| function In_Decl return Boolean; |
| -- Verify that node is not part of the type declaration for the |
| -- candidate type, which would otherwise be invisible. |
| |
| ------------- |
| -- In_Decl -- |
| ------------- |
| |
| function In_Decl return Boolean is |
| Decl_Node : constant Node_Id := Parent (E); |
| N2 : Node_Id; |
| |
| begin |
| N2 := N; |
| |
| if Etype (E) = Any_Type then |
| return True; |
| |
| elsif No (Decl_Node) then |
| return False; |
| |
| else |
| while Present (N2) |
| and then Nkind (N2) /= N_Compilation_Unit |
| loop |
| if N2 = Decl_Node then |
| return True; |
| else |
| N2 := Parent (N2); |
| end if; |
| end loop; |
| |
| return False; |
| end if; |
| end In_Decl; |
| |
| -- Start of processing for Type_In_P |
| |
| begin |
| -- If the context type is declared in the prefix package, this |
| -- is the desired base type. |
| |
| if Scope (Base_Type (Typ)) = Pack |
| and then Test (Typ) |
| then |
| return Base_Type (Typ); |
| |
| else |
| E := First_Entity (Pack); |
| |
| while Present (E) loop |
| |
| if Test (E) |
| and then not In_Decl |
| then |
| return E; |
| end if; |
| |
| Next_Entity (E); |
| end loop; |
| |
| return Empty; |
| end if; |
| end Type_In_P; |
| |
| -- Start of processing for Make_Call_Into_Operator |
| |
| begin |
| Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N)); |
| |
| -- Binary operator |
| |
| if Is_Binary then |
| Set_Left_Opnd (Op_Node, Relocate_Node (Act1)); |
| Set_Right_Opnd (Op_Node, Relocate_Node (Act2)); |
| Save_Interps (Act1, Left_Opnd (Op_Node)); |
| Save_Interps (Act2, Right_Opnd (Op_Node)); |
| Act1 := Left_Opnd (Op_Node); |
| Act2 := Right_Opnd (Op_Node); |
| |
| -- Unary operator |
| |
| else |
| Set_Right_Opnd (Op_Node, Relocate_Node (Act1)); |
| Save_Interps (Act1, Right_Opnd (Op_Node)); |
| Act1 := Right_Opnd (Op_Node); |
| end if; |
| |
| -- If the operator is denoted by an expanded name, and the prefix is |
| -- not Standard, but the operator is a predefined one whose scope is |
| -- Standard, then this is an implicit_operator, inserted as an |
| -- interpretation by the procedure of the same name. This procedure |
| -- overestimates the presence of implicit operators, because it does |
| -- not examine the type of the operands. Verify now that the operand |
| -- type appears in the given scope. If right operand is universal, |
| -- check the other operand. In the case of concatenation, either |
| -- argument can be the component type, so check the type of the result. |
| -- If both arguments are literals, look for a type of the right kind |
| -- defined in the given scope. This elaborate nonsense is brought to |
| -- you courtesy of b33302a. The type itself must be frozen, so we must |
| -- find the type of the proper class in the given scope. |
| |
| -- A final wrinkle is the multiplication operator for fixed point |
| -- types, which is defined in Standard only, and not in the scope of |
| -- the fixed_point type itself. |
| |
| if Nkind (Name (N)) = N_Expanded_Name then |
| Pack := Entity (Prefix (Name (N))); |
| |
| -- If the entity being called is defined in the given package, |
| -- it is a renaming of a predefined operator, and known to be |
| -- legal. |
| |
| if Scope (Entity (Name (N))) = Pack |
| and then Pack /= Standard_Standard |
| then |
| null; |
| |
| elsif (Op_Name = Name_Op_Multiply |
| or else Op_Name = Name_Op_Divide) |
| and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node))) |
| and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node))) |
| then |
| if Pack /= Standard_Standard then |
| Error := True; |
| end if; |
| |
| else |
| Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node))); |
| |
| if Op_Name = Name_Op_Concat then |
| Opnd_Type := Base_Type (Typ); |
| |
| elsif (Scope (Opnd_Type) = Standard_Standard |
| and then Is_Binary) |
| or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference |
| and then Is_Binary |
| and then not Comes_From_Source (Opnd_Type)) |
| then |
| Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node))); |
| end if; |
| |
| if Scope (Opnd_Type) = Standard_Standard then |
| |
| -- Verify that the scope contains a type that corresponds to |
| -- the given literal. Optimize the case where Pack is Standard. |
| |
| if Pack /= Standard_Standard then |
| |
| if Opnd_Type = Universal_Integer then |
| Orig_Type := Type_In_P (Is_Integer_Type'Access); |
| |
| elsif Opnd_Type = Universal_Real then |
| Orig_Type := Type_In_P (Is_Real_Type'Access); |
| |
| elsif Opnd_Type = Any_String then |
| Orig_Type := Type_In_P (Is_String_Type'Access); |
| |
| elsif Opnd_Type = Any_Access then |
| Orig_Type := Type_In_P (Is_Definite_Access_Type'Access); |
| |
| elsif Opnd_Type = Any_Composite then |
| Orig_Type := Type_In_P (Is_Composite_Type'Access); |
| |
| if Present (Orig_Type) then |
| if Has_Private_Component (Orig_Type) then |
| Orig_Type := Empty; |
| else |
| Set_Etype (Act1, Orig_Type); |
| |
| if Is_Binary then |
| Set_Etype (Act2, Orig_Type); |
| end if; |
| end if; |
| end if; |
| |
| else |
| Orig_Type := Empty; |
| end if; |
| |
| Error := No (Orig_Type); |
| end if; |
| |
| elsif Ekind (Opnd_Type) = E_Allocator_Type |
| and then No (Type_In_P (Is_Definite_Access_Type'Access)) |
| then |
| Error := True; |
| |
| -- If the type is defined elsewhere, and the operator is not |
| -- defined in the given scope (by a renaming declaration, e.g.) |
| -- then this is an error as well. If an extension of System is |
| -- present, and the type may be defined there, Pack must be |
| -- System itself. |
| |
| elsif Scope (Opnd_Type) /= Pack |
| and then Scope (Op_Id) /= Pack |
| and then (No (System_Aux_Id) |
| or else Scope (Opnd_Type) /= System_Aux_Id |
| or else Pack /= Scope (System_Aux_Id)) |
| then |
| Error := True; |
| |
| elsif Pack = Standard_Standard |
| and then not Operand_Type_In_Scope (Standard_Standard) |
| then |
| Error := True; |
| end if; |
| end if; |
| |
| if Error then |
| Error_Msg_Node_2 := Pack; |
| Error_Msg_NE |
| ("& not declared in&", N, Selector_Name (Name (N))); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| end if; |
| |
| Set_Chars (Op_Node, Op_Name); |
| |
| if not Is_Private_Type (Etype (N)) then |
| Set_Etype (Op_Node, Base_Type (Etype (N))); |
| else |
| Set_Etype (Op_Node, Etype (N)); |
| end if; |
| |
| Set_Entity (Op_Node, Op_Id); |
| Generate_Reference (Op_Id, N, ' '); |
| Rewrite (N, Op_Node); |
| |
| -- If this is an arithmetic operator and the result type is private, |
| -- the operands and the result must be wrapped in conversion to |
| -- expose the underlying numeric type and expand the proper checks, |
| -- e.g. on division. |
| |
| if Is_Private_Type (Typ) then |
| case Nkind (N) is |
| when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide | |
| N_Op_Expon | N_Op_Mod | N_Op_Rem => |
| Resolve_Intrinsic_Operator (N, Typ); |
| |
| when N_Op_Plus | N_Op_Minus | N_Op_Abs => |
| Resolve_Intrinsic_Unary_Operator (N, Typ); |
| |
| when others => |
| Resolve (N, Typ); |
| end case; |
| else |
| Resolve (N, Typ); |
| end if; |
| |
| -- For predefined operators on literals, the operation freezes |
| -- their type. |
| |
| if Present (Orig_Type) then |
| Set_Etype (Act1, Orig_Type); |
| Freeze_Expression (Act1); |
| end if; |
| end Make_Call_Into_Operator; |
| |
| ------------------- |
| -- Operator_Kind -- |
| ------------------- |
| |
| function Operator_Kind |
| (Op_Name : Name_Id; |
| Is_Binary : Boolean) |
| return Node_Kind |
| is |
| Kind : Node_Kind; |
| |
| begin |
| if Is_Binary then |
| if Op_Name = Name_Op_And then Kind := N_Op_And; |
| elsif Op_Name = Name_Op_Or then Kind := N_Op_Or; |
| elsif Op_Name = Name_Op_Xor then Kind := N_Op_Xor; |
| elsif Op_Name = Name_Op_Eq then Kind := N_Op_Eq; |
| elsif Op_Name = Name_Op_Ne then Kind := N_Op_Ne; |
| elsif Op_Name = Name_Op_Lt then Kind := N_Op_Lt; |
| elsif Op_Name = Name_Op_Le then Kind := N_Op_Le; |
| elsif Op_Name = Name_Op_Gt then Kind := N_Op_Gt; |
| elsif Op_Name = Name_Op_Ge then Kind := N_Op_Ge; |
| elsif Op_Name = Name_Op_Add then Kind := N_Op_Add; |
| elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Subtract; |
| elsif Op_Name = Name_Op_Concat then Kind := N_Op_Concat; |
| elsif Op_Name = Name_Op_Multiply then Kind := N_Op_Multiply; |
| elsif Op_Name = Name_Op_Divide then Kind := N_Op_Divide; |
| elsif Op_Name = Name_Op_Mod then Kind := N_Op_Mod; |
| elsif Op_Name = Name_Op_Rem then Kind := N_Op_Rem; |
| elsif Op_Name = Name_Op_Expon then Kind := N_Op_Expon; |
| else |
| raise Program_Error; |
| end if; |
| |
| -- Unary operators |
| |
| else |
| if Op_Name = Name_Op_Add then Kind := N_Op_Plus; |
| elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Minus; |
| elsif Op_Name = Name_Op_Abs then Kind := N_Op_Abs; |
| elsif Op_Name = Name_Op_Not then Kind := N_Op_Not; |
| else |
| raise Program_Error; |
| end if; |
| end if; |
| |
| return Kind; |
| end Operator_Kind; |
| |
| ----------------------------- |
| -- Pre_Analyze_And_Resolve -- |
| ----------------------------- |
| |
| procedure Pre_Analyze_And_Resolve (N : Node_Id; T : Entity_Id) is |
| Save_Full_Analysis : constant Boolean := Full_Analysis; |
| |
| begin |
| Full_Analysis := False; |
| Expander_Mode_Save_And_Set (False); |
| |
| -- We suppress all checks for this analysis, since the checks will |
| -- be applied properly, and in the right location, when the default |
| -- expression is reanalyzed and reexpanded later on. |
| |
| Analyze_And_Resolve (N, T, Suppress => All_Checks); |
| |
| Expander_Mode_Restore; |
| Full_Analysis := Save_Full_Analysis; |
| end Pre_Analyze_And_Resolve; |
| |
| -- Version without context type. |
| |
| procedure Pre_Analyze_And_Resolve (N : Node_Id) is |
| Save_Full_Analysis : constant Boolean := Full_Analysis; |
| |
| begin |
| Full_Analysis := False; |
| Expander_Mode_Save_And_Set (False); |
| |
| Analyze (N); |
| Resolve (N, Etype (N), Suppress => All_Checks); |
| |
| Expander_Mode_Restore; |
| Full_Analysis := Save_Full_Analysis; |
| end Pre_Analyze_And_Resolve; |
| |
| ---------------------------------- |
| -- Replace_Actual_Discriminants -- |
| ---------------------------------- |
| |
| procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Tsk : Node_Id := Empty; |
| |
| function Process_Discr (Nod : Node_Id) return Traverse_Result; |
| |
| ------------------- |
| -- Process_Discr -- |
| ------------------- |
| |
| function Process_Discr (Nod : Node_Id) return Traverse_Result is |
| Ent : Entity_Id; |
| |
| begin |
| if Nkind (Nod) = N_Identifier then |
| Ent := Entity (Nod); |
| |
| if Present (Ent) |
| and then Ekind (Ent) = E_Discriminant |
| then |
| Rewrite (Nod, |
| Make_Selected_Component (Loc, |
| Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc), |
| Selector_Name => Make_Identifier (Loc, Chars (Ent)))); |
| |
| Set_Etype (Nod, Etype (Ent)); |
| end if; |
| |
| end if; |
| |
| return OK; |
| end Process_Discr; |
| |
| procedure Replace_Discrs is new Traverse_Proc (Process_Discr); |
| |
| -- Start of processing for Replace_Actual_Discriminants |
| |
| begin |
| if not Expander_Active then |
| return; |
| end if; |
| |
| if Nkind (Name (N)) = N_Selected_Component then |
| Tsk := Prefix (Name (N)); |
| |
| elsif Nkind (Name (N)) = N_Indexed_Component then |
| Tsk := Prefix (Prefix (Name (N))); |
| end if; |
| |
| if No (Tsk) then |
| return; |
| else |
| Replace_Discrs (Default); |
| end if; |
| end Replace_Actual_Discriminants; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| procedure Resolve (N : Node_Id; Typ : Entity_Id) is |
| I : Interp_Index; |
| I1 : Interp_Index := 0; -- prevent junk warning |
| It : Interp; |
| It1 : Interp; |
| Found : Boolean := False; |
| Seen : Entity_Id := Empty; -- prevent junk warning |
| Ctx_Type : Entity_Id := Typ; |
| Expr_Type : Entity_Id := Empty; -- prevent junk warning |
| Err_Type : Entity_Id := Empty; |
| Ambiguous : Boolean := False; |
| |
| procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id); |
| -- Try and fix up a literal so that it matches its expected type. New |
| -- literals are manufactured if necessary to avoid cascaded errors. |
| |
| procedure Resolution_Failed; |
| -- Called when attempt at resolving current expression fails |
| |
| -------------------- |
| -- Patch_Up_Value -- |
| -------------------- |
| |
| procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is |
| begin |
| if Nkind (N) = N_Integer_Literal |
| and then Is_Real_Type (Typ) |
| then |
| Rewrite (N, |
| Make_Real_Literal (Sloc (N), |
| Realval => UR_From_Uint (Intval (N)))); |
| Set_Etype (N, Universal_Real); |
| Set_Is_Static_Expression (N); |
| |
| elsif Nkind (N) = N_Real_Literal |
| and then Is_Integer_Type (Typ) |
| then |
| Rewrite (N, |
| Make_Integer_Literal (Sloc (N), |
| Intval => UR_To_Uint (Realval (N)))); |
| Set_Etype (N, Universal_Integer); |
| Set_Is_Static_Expression (N); |
| elsif Nkind (N) = N_String_Literal |
| and then Is_Character_Type (Typ) |
| then |
| Set_Character_Literal_Name (Char_Code (Character'Pos ('A'))); |
| Rewrite (N, |
| Make_Character_Literal (Sloc (N), |
| Chars => Name_Find, |
| Char_Literal_Value => Char_Code (Character'Pos ('A')))); |
| Set_Etype (N, Any_Character); |
| Set_Is_Static_Expression (N); |
| |
| elsif Nkind (N) /= N_String_Literal |
| and then Is_String_Type (Typ) |
| then |
| Rewrite (N, |
| Make_String_Literal (Sloc (N), |
| Strval => End_String)); |
| |
| elsif Nkind (N) = N_Range then |
| Patch_Up_Value (Low_Bound (N), Typ); |
| Patch_Up_Value (High_Bound (N), Typ); |
| end if; |
| end Patch_Up_Value; |
| |
| ----------------------- |
| -- Resolution_Failed -- |
| ----------------------- |
| |
| procedure Resolution_Failed is |
| begin |
| Patch_Up_Value (N, Typ); |
| Set_Etype (N, Typ); |
| Debug_A_Exit ("resolving ", N, " (done, resolution failed)"); |
| Set_Is_Overloaded (N, False); |
| |
| -- The caller will return without calling the expander, so we need |
| -- to set the analyzed flag. Note that it is fine to set Analyzed |
| -- to True even if we are in the middle of a shallow analysis, |
| -- (see the spec of sem for more details) since this is an error |
| -- situation anyway, and there is no point in repeating the |
| -- analysis later (indeed it won't work to repeat it later, since |
| -- we haven't got a clear resolution of which entity is being |
| -- referenced.) |
| |
| Set_Analyzed (N, True); |
| return; |
| end Resolution_Failed; |
| |
| -- Start of processing for Resolve |
| |
| begin |
| if N = Error then |
| return; |
| end if; |
| |
| -- Access attribute on remote subprogram cannot be used for |
| -- a non-remote access-to-subprogram type. |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then (Attribute_Name (N) = Name_Access |
| or else Attribute_Name (N) = Name_Unrestricted_Access |
| or else Attribute_Name (N) = Name_Unchecked_Access) |
| and then Comes_From_Source (N) |
| and then Is_Entity_Name (Prefix (N)) |
| and then Is_Subprogram (Entity (Prefix (N))) |
| and then Is_Remote_Call_Interface (Entity (Prefix (N))) |
| and then not Is_Remote_Access_To_Subprogram_Type (Typ) |
| then |
| Error_Msg_N |
| ("prefix must statically denote a non-remote subprogram", N); |
| end if; |
| |
| -- If the context is a Remote_Access_To_Subprogram, access attributes |
| -- must be resolved with the corresponding fat pointer. There is no need |
| -- to check for the attribute name since the return type of an |
| -- attribute is never a remote type. |
| |
| if Nkind (N) = N_Attribute_Reference |
| and then Comes_From_Source (N) |
| and then (Is_Remote_Call_Interface (Typ) |
| or else Is_Remote_Types (Typ)) |
| then |
| declare |
| Attr : constant Attribute_Id := |
| Get_Attribute_Id (Attribute_Name (N)); |
| Pref : constant Node_Id := Prefix (N); |
| Decl : Node_Id; |
| Spec : Node_Id; |
| Is_Remote : Boolean := True; |
| |
| begin |
| -- Check that Typ is a fat pointer with a reference to a RAS as |
| -- original access type. |
| |
| if |
| (Ekind (Typ) = E_Access_Subprogram_Type |
| and then Present (Equivalent_Type (Typ))) |
| or else |
| (Ekind (Typ) = E_Record_Type |
| and then Present (Corresponding_Remote_Type (Typ))) |
| |
| then |
| -- Prefix (N) must statically denote a remote subprogram |
| -- declared in a package specification. |
| |
| if Attr = Attribute_Access then |
| Decl := Unit_Declaration_Node (Entity (Pref)); |
| |
| if Nkind (Decl) = N_Subprogram_Body then |
| Spec := Corresponding_Spec (Decl); |
| |
| if not No (Spec) then |
| Decl := Unit_Declaration_Node (Spec); |
| end if; |
| end if; |
| |
| Spec := Parent (Decl); |
| |
| if not Is_Entity_Name (Prefix (N)) |
| or else Nkind (Spec) /= N_Package_Specification |
| or else |
| not Is_Remote_Call_Interface (Defining_Entity (Spec)) |
| then |
| Is_Remote := False; |
| Error_Msg_N |
| ("prefix must statically denote a remote subprogram ", |
| N); |
| end if; |
| end if; |
| |
| -- If we are generating code for a distributed program. |
| -- perform semantic checks against the corresponding |
| -- remote entities. |
| |
| if (Attr = Attribute_Access |
| or else Attr = Attribute_Unchecked_Access |
| or else Attr = Attribute_Unrestricted_Access) |
| and then Expander_Active |
| then |
| Check_Subtype_Conformant |
| (New_Id => Entity (Prefix (N)), |
| Old_Id => Designated_Type |
| (Corresponding_Remote_Type (Typ)), |
| Err_Loc => N); |
| if Is_Remote then |
| Process_Remote_AST_Attribute (N, Typ); |
| end if; |
| end if; |
| end if; |
| end; |
| end if; |
| |
| Debug_A_Entry ("resolving ", N); |
| |
| if Comes_From_Source (N) then |
| if Is_Fixed_Point_Type (Typ) then |
| Check_Restriction (No_Fixed_Point, N); |
| |
| elsif Is_Floating_Point_Type (Typ) |
| and then Typ /= Universal_Real |
| and then Typ /= Any_Real |
| then |
| Check_Restriction (No_Floating_Point, N); |
| end if; |
| end if; |
| |
| -- Return if already analyzed |
| |
| if Analyzed (N) then |
| Debug_A_Exit ("resolving ", N, " (done, already analyzed)"); |
| return; |
| |
| -- Return if type = Any_Type (previous error encountered) |
| |
| elsif Etype (N) = Any_Type then |
| Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)"); |
| return; |
| end if; |
| |
| Check_Parameterless_Call (N); |
| |
| -- If not overloaded, then we know the type, and all that needs doing |
| -- is to check that this type is compatible with the context. |
| |
| if not Is_Overloaded (N) then |
| Found := Covers (Typ, Etype (N)); |
| Expr_Type := Etype (N); |
| |
| -- In the overloaded case, we must select the interpretation that |
| -- is compatible with the context (i.e. the type passed to Resolve) |
| |
| else |
| Get_First_Interp (N, I, It); |
| |
| -- Loop through possible interpretations |
| |
| Interp_Loop : while Present (It.Typ) loop |
| |
| -- We are only interested in interpretations that are compatible |
| -- with the expected type, any other interpretations are ignored |
| |
| if not Covers (Typ, It.Typ) then |
| if Debug_Flag_V then |
| Write_Str (" interpretation incompatible with context"); |
| Write_Eol; |
| end if; |
| |
| else |
| -- First matching interpretation |
| |
| if not Found then |
| Found := True; |
| I1 := I; |
| Seen := It.Nam; |
| Expr_Type := It.Typ; |
| |
| -- Matching interpretation that is not the first, maybe an |
| -- error, but there are some cases where preference rules are |
| -- used to choose between the two possibilities. These and |
| -- some more obscure cases are handled in Disambiguate. |
| |
| else |
| Error_Msg_Sloc := Sloc (Seen); |
| It1 := Disambiguate (N, I1, I, Typ); |
| |
| -- Disambiguation has succeeded. Skip the remaining |
| -- interpretations. |
| |
| if It1 /= No_Interp then |
| Seen := It1.Nam; |
| Expr_Type := It1.Typ; |
| |
| while Present (It.Typ) loop |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| else |
| -- Before we issue an ambiguity complaint, check for |
| -- the case of a subprogram call where at least one |
| -- of the arguments is Any_Type, and if so, suppress |
| -- the message, since it is a cascaded error. |
| |
| if Nkind (N) = N_Function_Call |
| or else Nkind (N) = N_Procedure_Call_Statement |
| then |
| declare |
| A : Node_Id := First_Actual (N); |
| E : Node_Id; |
| |
| begin |
| while Present (A) loop |
| E := A; |
| |
| if Nkind (E) = N_Parameter_Association then |
| E := Explicit_Actual_Parameter (E); |
| end if; |
| |
| if Etype (E) = Any_Type then |
| if Debug_Flag_V then |
| Write_Str ("Any_Type in call"); |
| Write_Eol; |
| end if; |
| |
| exit Interp_Loop; |
| end if; |
| |
| Next_Actual (A); |
| end loop; |
| end; |
| |
| elsif Nkind (N) in N_Binary_Op |
| and then (Etype (Left_Opnd (N)) = Any_Type |
| or else Etype (Right_Opnd (N)) = Any_Type) |
| then |
| exit Interp_Loop; |
| |
| elsif Nkind (N) in N_Unary_Op |
| and then Etype (Right_Opnd (N)) = Any_Type |
| then |
| exit Interp_Loop; |
| end if; |
| |
| -- Not that special case, so issue message using the |
| -- flag Ambiguous to control printing of the header |
| -- message only at the start of an ambiguous set. |
| |
| if not Ambiguous then |
| Error_Msg_NE |
| ("ambiguous expression (cannot resolve&)!", |
| N, It.Nam); |
| |
| Error_Msg_N |
| ("possible interpretation#!", N); |
| Ambiguous := True; |
| end if; |
| |
| Error_Msg_Sloc := Sloc (It.Nam); |
| |
| -- By default, the error message refers to the candidate |
| -- interpretation. But if it is a predefined operator, |
| -- it is implicitly declared at the declaration of |
| -- the type of the operand. Recover the sloc of that |
| -- declaration for the error message. |
| |
| if Nkind (N) in N_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then not Is_Overloaded (Right_Opnd (N)) |
| and then Scope (Base_Type (Etype (Right_Opnd (N)))) |
| /= Standard_Standard |
| then |
| Err_Type := First_Subtype (Etype (Right_Opnd (N))); |
| |
| if Comes_From_Source (Err_Type) |
| and then Present (Parent (Err_Type)) |
| then |
| Error_Msg_Sloc := Sloc (Parent (Err_Type)); |
| end if; |
| |
| elsif Nkind (N) in N_Binary_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then not Is_Overloaded (Left_Opnd (N)) |
| and then Scope (Base_Type (Etype (Left_Opnd (N)))) |
| /= Standard_Standard |
| then |
| Err_Type := First_Subtype (Etype (Left_Opnd (N))); |
| |
| if Comes_From_Source (Err_Type) |
| and then Present (Parent (Err_Type)) |
| then |
| Error_Msg_Sloc := Sloc (Parent (Err_Type)); |
| end if; |
| else |
| Err_Type := Empty; |
| end if; |
| |
| if Nkind (N) in N_Op |
| and then Scope (It.Nam) = Standard_Standard |
| and then Present (Err_Type) |
| then |
| Error_Msg_N |
| ("possible interpretation (predefined)#!", N); |
| else |
| Error_Msg_N ("possible interpretation#!", N); |
| end if; |
| |
| end if; |
| end if; |
| |
| -- We have a matching interpretation, Expr_Type is the |
| -- type from this interpretation, and Seen is the entity. |
| |
| -- For an operator, just set the entity name. The type will |
| -- be set by the specific operator resolution routine. |
| |
| if Nkind (N) in N_Op then |
| Set_Entity (N, Seen); |
| Generate_Reference (Seen, N); |
| |
| elsif Nkind (N) = N_Character_Literal then |
| Set_Etype (N, Expr_Type); |
| |
| -- For an explicit dereference, attribute reference, range, |
| -- short-circuit form (which is not an operator node), |
| -- or a call with a name that is an explicit dereference, |
| -- there is nothing to be done at this point. |
| |
| elsif Nkind (N) = N_Explicit_Dereference |
| or else Nkind (N) = N_Attribute_Reference |
| or else Nkind (N) = N_And_Then |
| or else Nkind (N) = N_Indexed_Component |
| or else Nkind (N) = N_Or_Else |
| or else Nkind (N) = N_Range |
| or else Nkind (N) = N_Selected_Component |
| or else Nkind (N) = N_Slice |
| or else Nkind (Name (N)) = N_Explicit_Dereference |
| then |
| null; |
| |
| -- For procedure or function calls, set the type of the |
| -- name, and also the entity pointer for the prefix |
| |
| elsif (Nkind (N) = N_Procedure_Call_Statement |
| or else Nkind (N) = N_Function_Call) |
| and then (Is_Entity_Name (Name (N)) |
| or else Nkind (Name (N)) = N_Operator_Symbol) |
| then |
| Set_Etype (Name (N), Expr_Type); |
| Set_Entity (Name (N), Seen); |
| Generate_Reference (Seen, Name (N)); |
| |
| elsif Nkind (N) = N_Function_Call |
| and then Nkind (Name (N)) = N_Selected_Component |
| then |
| Set_Etype (Name (N), Expr_Type); |
| Set_Entity (Selector_Name (Name (N)), Seen); |
| Generate_Reference (Seen, Selector_Name (Name (N))); |
| |
| -- For all other cases, just set the type of the Name |
| |
| else |
| Set_Etype (Name (N), Expr_Type); |
| end if; |
| |
| end if; |
| |
| -- Move to next interpretation |
| |
| exit Interp_Loop when not Present (It.Typ); |
| |
| Get_Next_Interp (I, It); |
| end loop Interp_Loop; |
| end if; |
| |
| -- At this stage Found indicates whether or not an acceptable |
| -- interpretation exists. If not, then we have an error, except |
| -- that if the context is Any_Type as a result of some other error, |
| -- then we suppress the error report. |
| |
| if not Found then |
| if Typ /= Any_Type then |
| |
| -- If type we are looking for is Void, then this is the |
| -- procedure call case, and the error is simply that what |
| -- we gave is not a procedure name (we think of procedure |
| -- calls as expressions with types internally, but the user |
| -- doesn't think of them this way!) |
| |
| if Typ = Standard_Void_Type then |
| |
| -- Special case message if function used as a procedure |
| |
| if Nkind (N) = N_Procedure_Call_Statement |
| and then Is_Entity_Name (Name (N)) |
| and then Ekind (Entity (Name (N))) = E_Function |
| then |
| Error_Msg_NE |
| ("cannot use function & in a procedure call", |
| Name (N), Entity (Name (N))); |
| |
| -- Otherwise give general message (not clear what cases |
| -- this covers, but no harm in providing for them!) |
| |
| else |
| Error_Msg_N ("expect procedure name in procedure call", N); |
| end if; |
| |
| Found := True; |
| |
| -- Otherwise we do have a subexpression with the wrong type |
| |
| -- Check for the case of an allocator which uses an access |
| -- type instead of the designated type. This is a common |
| -- error and we specialize the message, posting an error |
| -- on the operand of the allocator, complaining that we |
| -- expected the designated type of the allocator. |
| |
| elsif Nkind (N) = N_Allocator |
| and then Ekind (Typ) in Access_Kind |
| and then Ekind (Etype (N)) in Access_Kind |
| and then Designated_Type (Etype (N)) = Typ |
| then |
| Wrong_Type (Expression (N), Designated_Type (Typ)); |
| Found := True; |
| |
| -- Check for view mismatch on Null in instances, for |
| -- which the view-swapping mechanism has no identifier. |
| |
| elsif (In_Instance or else In_Inlined_Body) |
| and then (Nkind (N) = N_Null) |
| and then Is_Private_Type (Typ) |
| and then Is_Access_Type (Full_View (Typ)) |
| then |
| Resolve (N, Full_View (Typ)); |
| Set_Etype (N, Typ); |
| return; |
| |
| -- Check for an aggregate. Sometimes we can get bogus |
| -- aggregates from misuse of parentheses, and we are |
| -- about to complain about the aggregate without even |
| -- looking inside it. |
| |
| -- Instead, if we have an aggregate of type Any_Composite, |
| -- then analyze and resolve the component fields, and then |
| -- only issue another message if we get no errors doing |
| -- this (otherwise assume that the errors in the aggregate |
| -- caused the problem). |
| |
| elsif Nkind (N) = N_Aggregate |
| and then Etype (N) = Any_Composite |
| then |
| -- Disable expansion in any case. If there is a type mismatch |
| -- it may be fatal to try to expand the aggregate. The flag |
| -- would otherwise be set to false when the error is posted. |
| |
| Expander_Active := False; |
| |
| declare |
| procedure Check_Aggr (Aggr : Node_Id); |
| -- Check one aggregate, and set Found to True if we |
| -- have a definite error in any of its elements |
| |
| procedure Check_Elmt (Aelmt : Node_Id); |
| -- Check one element of aggregate and set Found to |
| -- True if we definitely have an error in the element. |
| |
| procedure Check_Aggr (Aggr : Node_Id) is |
| Elmt : Node_Id; |
| |
| begin |
| if Present (Expressions (Aggr)) then |
| Elmt := First (Expressions (Aggr)); |
| while Present (Elmt) loop |
| Check_Elmt (Elmt); |
| Next (Elmt); |
| end loop; |
| end if; |
| |
| if Present (Component_Associations (Aggr)) then |
| Elmt := First (Component_Associations (Aggr)); |
| while Present (Elmt) loop |
| Check_Elmt (Expression (Elmt)); |
| Next (Elmt); |
| end loop; |
| end if; |
| end Check_Aggr; |
| |
| ---------------- |
| -- Check_Elmt -- |
| ---------------- |
| |
| procedure Check_Elmt (Aelmt : Node_Id) is |
| begin |
| -- If we have a nested aggregate, go inside it (to |
| -- attempt a naked analyze-resolve of the aggregate |
| -- can cause undesirable cascaded errors). Do not |
| -- resolve expression if it needs a type from context, |
| -- as for integer * fixed expression. |
| |
| if Nkind (Aelmt) = N_Aggregate then |
| Check_Aggr (Aelmt); |
| |
| else |
| Analyze (Aelmt); |
| |
| if not Is_Overloaded (Aelmt) |
| and then Etype (Aelmt) /= Any_Fixed |
| then |
| Resolve (Aelmt); |
| end if; |
| |
| if Etype (Aelmt) = Any_Type then |
| Found := True; |
| end if; |
| end if; |
| end Check_Elmt; |
| |
| begin |
| Check_Aggr (N); |
| end; |
| end if; |
| |
| -- If an error message was issued already, Found got reset |
| -- to True, so if it is still False, issue the standard |
| -- Wrong_Type message. |
| |
| if not Found then |
| if Is_Overloaded (N) |
| and then Nkind (N) = N_Function_Call |
| then |
| declare |
| Subp_Name : Node_Id; |
| begin |
| if Is_Entity_Name (Name (N)) then |
| Subp_Name := Name (N); |
| |
| elsif Nkind (Name (N)) = N_Selected_Component then |
| |
| -- Protected operation: retrieve operation name. |
| |
| Subp_Name := Selector_Name (Name (N)); |
| else |
| raise Program_Error; |
| end if; |
| |
| Error_Msg_Node_2 := Typ; |
| Error_Msg_NE ("no visible interpretation of&" & |
| " matches expected type&", N, Subp_Name); |
| end; |
| |
| if All_Errors_Mode then |
| declare |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| Error_Msg_N ("\possible interpretations:", N); |
| Get_First_Interp (Name (N), Index, It); |
| |
| while Present (It.Nam) loop |
| |
| Error_Msg_Sloc := Sloc (It.Nam); |
| Error_Msg_Node_2 := It.Typ; |
| Error_Msg_NE ("\& declared#, type&", |
| N, It.Nam); |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end; |
| else |
| Error_Msg_N ("\use -gnatf for details", N); |
| end if; |
| else |
| Wrong_Type (N, Typ); |
| end if; |
| end if; |
| end if; |
| |
| Resolution_Failed; |
| return; |
| |
| -- Test if we have more than one interpretation for the context |
| |
| elsif Ambiguous then |
| Resolution_Failed; |
| return; |
| |
| -- Here we have an acceptable interpretation for the context |
| |
| else |
| -- A user-defined operator is tranformed into a function call at |
| -- this point, so that further processing knows that operators are |
| -- really operators (i.e. are predefined operators). User-defined |
| -- operators that are intrinsic are just renamings of the predefined |
| -- ones, and need not be turned into calls either, but if they rename |
| -- a different operator, we must transform the node accordingly. |
| -- Instantiations of Unchecked_Conversion are intrinsic but are |
| -- treated as functions, even if given an operator designator. |
| |
| if Nkind (N) in N_Op |
| and then Present (Entity (N)) |
| and then Ekind (Entity (N)) /= E_Operator |
| then |
| |
| if not Is_Predefined_Op (Entity (N)) then |
| Rewrite_Operator_As_Call (N, Entity (N)); |
| |
| elsif Present (Alias (Entity (N))) then |
| Rewrite_Renamed_Operator (N, Alias (Entity (N))); |
| end if; |
| end if; |
| |
| -- Propagate type information and normalize tree for various |
| -- predefined operations. If the context only imposes a class of |
| -- types, rather than a specific type, propagate the actual type |
| -- downward. |
| |
| if Typ = Any_Integer |
| or else Typ = Any_Boolean |
| or else Typ = Any_Modular |
| or else Typ = Any_Real |
| or else Typ = Any_Discrete |
| then |
| Ctx_Type := Expr_Type; |
| |
| -- Any_Fixed is legal in a real context only if a specific |
| -- fixed point type is imposed. If Norman Cohen can be |
| -- confused by this, it deserves a separate message. |
| |
| if Typ = Any_Real |
| and then Expr_Type = Any_Fixed |
| then |
| Error_Msg_N ("Illegal context for mixed mode operation", N); |
| Set_Etype (N, Universal_Real); |
| Ctx_Type := Universal_Real; |
| end if; |
| end if; |
| |
| case N_Subexpr'(Nkind (N)) is |
| |
| when N_Aggregate => Resolve_Aggregate (N, Ctx_Type); |
| |
| when N_Allocator => Resolve_Allocator (N, Ctx_Type); |
| |
| when N_And_Then | N_Or_Else |
| => Resolve_Short_Circuit (N, Ctx_Type); |
| |
| when N_Attribute_Reference |
| => Resolve_Attribute (N, Ctx_Type); |
| |
| when N_Character_Literal |
| => Resolve_Character_Literal (N, Ctx_Type); |
| |
| when N_Conditional_Expression |
| => Resolve_Conditional_Expression (N, Ctx_Type); |
| |
| when N_Expanded_Name |
| => Resolve_Entity_Name (N, Ctx_Type); |
| |
| when N_Extension_Aggregate |
| => Resolve_Extension_Aggregate (N, Ctx_Type); |
| |
| when N_Explicit_Dereference |
| => Resolve_Explicit_Dereference (N, Ctx_Type); |
| |
| when N_Function_Call |
| => Resolve_Call (N, Ctx_Type); |
| |
| when N_Identifier |
| => Resolve_Entity_Name (N, Ctx_Type); |
| |
| when N_In | N_Not_In |
| => Resolve_Membership_Op (N, Ctx_Type); |
| |
| when N_Indexed_Component |
| => Resolve_Indexed_Component (N, Ctx_Type); |
| |
| when N_Integer_Literal |
| => Resolve_Integer_Literal (N, Ctx_Type); |
| |
| when N_Null => Resolve_Null (N, Ctx_Type); |
| |
| when N_Op_And | N_Op_Or | N_Op_Xor |
| => Resolve_Logical_Op (N, Ctx_Type); |
| |
| when N_Op_Eq | N_Op_Ne |
| => Resolve_Equality_Op (N, Ctx_Type); |
| |
| when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge |
| => Resolve_Comparison_Op (N, Ctx_Type); |
| |
| when N_Op_Not => Resolve_Op_Not (N, Ctx_Type); |
| |
| when N_Op_Add | N_Op_Subtract | N_Op_Multiply | |
| N_Op_Divide | N_Op_Mod | N_Op_Rem |
| |
| => Resolve_Arithmetic_Op (N, Ctx_Type); |
| |
| when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type); |
| |
| when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type); |
| |
| when N_Op_Plus | N_Op_Minus | N_Op_Abs |
| => Resolve_Unary_Op (N, Ctx_Type); |
| |
| when N_Op_Shift => Resolve_Shift (N, Ctx_Type); |
| |
| when N_Procedure_Call_Statement |
| => Resolve_Call (N, Ctx_Type); |
| |
| when N_Operator_Symbol |
| => Resolve_Operator_Symbol (N, Ctx_Type); |
| |
| when N_Qualified_Expression |
| => Resolve_Qualified_Expression (N, Ctx_Type); |
| |
| when N_Raise_xxx_Error |
| => Set_Etype (N, Ctx_Type); |
| |
| when N_Range => Resolve_Range (N, Ctx_Type); |
| |
| when N_Real_Literal |
| => Resolve_Real_Literal (N, Ctx_Type); |
| |
| when N_Reference => Resolve_Reference (N, Ctx_Type); |
| |
| when N_Selected_Component |
| => Resolve_Selected_Component (N, Ctx_Type); |
| |
| when N_Slice => Resolve_Slice (N, Ctx_Type); |
| |
| when N_String_Literal |
| => Resolve_String_Literal (N, Ctx_Type); |
| |
| when N_Subprogram_Info |
| => Resolve_Subprogram_Info (N, Ctx_Type); |
| |
| when N_Type_Conversion |
| => Resolve_Type_Conversion (N, Ctx_Type); |
| |
| when N_Unchecked_Expression => |
| Resolve_Unchecked_Expression (N, Ctx_Type); |
| |
| when N_Unchecked_Type_Conversion => |
| Resolve_Unchecked_Type_Conversion (N, Ctx_Type); |
| |
| end case; |
| |
| -- If the subexpression was replaced by a non-subexpression, then |
| -- all we do is to expand it. The only legitimate case we know of |
| -- is converting procedure call statement to entry call statements, |
| -- but there may be others, so we are making this test general. |
| |
| if Nkind (N) not in N_Subexpr then |
| Debug_A_Exit ("resolving ", N, " (done)"); |
| Expand (N); |
| return; |
| end if; |
| |
| -- The expression is definitely NOT overloaded at this point, so |
| -- we reset the Is_Overloaded flag to avoid any confusion when |
| -- reanalyzing the node. |
| |
| Set_Is_Overloaded (N, False); |
| |
| -- Freeze expression type, entity if it is a name, and designated |
| -- type if it is an allocator (RM 13.14(10,11,13)). |
| |
| -- Now that the resolution of the type of the node is complete, |
| -- and we did not detect an error, we can expand this node. We |
| -- skip the expand call if we are in a default expression, see |
| -- section "Handling of Default Expressions" in Sem spec. |
| |
| Debug_A_Exit ("resolving ", N, " (done)"); |
| |
| -- We unconditionally freeze the expression, even if we are in |
| -- default expression mode (the Freeze_Expression routine tests |
| -- this flag and only freezes static types if it is set). |
| |
| Freeze_Expression (N); |
| |
| -- Now we can do the expansion |
| |
| Expand (N); |
| end if; |
| end Resolve; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| -- Version with check(s) suppressed |
| |
| procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is |
| begin |
| if Suppress = All_Checks then |
| declare |
| Svg : constant Suppress_Array := Scope_Suppress; |
| |
| begin |
| Scope_Suppress := (others => True); |
| Resolve (N, Typ); |
| Scope_Suppress := Svg; |
| end; |
| |
| else |
| declare |
| Svg : constant Boolean := Scope_Suppress (Suppress); |
| |
| begin |
| Scope_Suppress (Suppress) := True; |
| Resolve (N, Typ); |
| Scope_Suppress (Suppress) := Svg; |
| end; |
| end if; |
| end Resolve; |
| |
| ------------- |
| -- Resolve -- |
| ------------- |
| |
| -- Version with implicit type |
| |
| procedure Resolve (N : Node_Id) is |
| begin |
| Resolve (N, Etype (N)); |
| end Resolve; |
| |
| --------------------- |
| -- Resolve_Actuals -- |
| --------------------- |
| |
| procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| A : Node_Id; |
| F : Entity_Id; |
| A_Typ : Entity_Id; |
| F_Typ : Entity_Id; |
| Prev : Node_Id := Empty; |
| |
| procedure Insert_Default; |
| -- If the actual is missing in a call, insert in the actuals list |
| -- an instance of the default expression. The insertion is always |
| -- a named association. |
| |
| function Same_Ancestor (T1, T2 : Entity_Id) return Boolean; |
| -- Check whether T1 and T2, or their full views, are derived from a |
| -- common type. Used to enforce the restrictions on array conversions |
| -- of AI95-00246. |
| |
| -------------------- |
| -- Insert_Default -- |
| -------------------- |
| |
| procedure Insert_Default is |
| Actval : Node_Id; |
| Assoc : Node_Id; |
| |
| begin |
| -- Missing argument in call, nothing to insert |
| |
| if No (Default_Value (F)) then |
| return; |
| |
| else |
| -- Note that we do a full New_Copy_Tree, so that any associated |
| -- Itypes are properly copied. This may not be needed any more, |
| -- but it does no harm as a safety measure! Defaults of a generic |
| -- formal may be out of bounds of the corresponding actual (see |
| -- cc1311b) and an additional check may be required. |
| |
| Actval := New_Copy_Tree (Default_Value (F), |
| New_Scope => Current_Scope, New_Sloc => Loc); |
| |
| if Is_Concurrent_Type (Scope (Nam)) |
| and then Has_Discriminants (Scope (Nam)) |
| then |
| Replace_Actual_Discriminants (N, Actval); |
| end if; |
| |
| if Is_Overloadable (Nam) |
| and then Present (Alias (Nam)) |
| then |
| if Base_Type (Etype (F)) /= Base_Type (Etype (Actval)) |
| and then not Is_Tagged_Type (Etype (F)) |
| then |
| -- If default is a real literal, do not introduce a |
| -- conversion whose effect may depend on the run-time |
| -- size of universal real. |
| |
| if Nkind (Actval) = N_Real_Literal then |
| Set_Etype (Actval, Base_Type (Etype (F))); |
| else |
| Actval := Unchecked_Convert_To (Etype (F), Actval); |
| end if; |
| end if; |
| |
| if Is_Scalar_Type (Etype (F)) then |
| Enable_Range_Check (Actval); |
| end if; |
| |
| Set_Parent (Actval, N); |
| |
| -- Resolve aggregates with their base type, to avoid scope |
| -- anomalies: the subtype was first built in the suprogram |
| -- declaration, and the current call may be nested. |
| |
| if Nkind (Actval) = N_Aggregate |
| and then Has_Discriminants (Etype (Actval)) |
| then |
| Analyze_And_Resolve (Actval, Base_Type (Etype (Actval))); |
| else |
| Analyze_And_Resolve (Actval, Etype (Actval)); |
| end if; |
| |
| else |
| Set_Parent (Actval, N); |
| |
| -- See note above concerning aggregates. |
| |
| if Nkind (Actval) = N_Aggregate |
| and then Has_Discriminants (Etype (Actval)) |
| then |
| Analyze_And_Resolve (Actval, Base_Type (Etype (Actval))); |
| |
| -- Resolve entities with their own type, which may differ |
| -- from the type of a reference in a generic context (the |
| -- view swapping mechanism did not anticipate the re-analysis |
| -- of default values in calls). |
| |
| elsif Is_Entity_Name (Actval) then |
| Analyze_And_Resolve (Actval, Etype (Entity (Actval))); |
| |
| else |
| Analyze_And_Resolve (Actval, Etype (Actval)); |
| end if; |
| end if; |
| |
| -- If default is a tag indeterminate function call, propagate |
| -- tag to obtain proper dispatching. |
| |
| if Is_Controlling_Formal (F) |
| and then Nkind (Default_Value (F)) = N_Function_Call |
| then |
| Set_Is_Controlling_Actual (Actval); |
| end if; |
| |
| end if; |
| |
| -- If the default expression raises constraint error, then just |
| -- silently replace it with an N_Raise_Constraint_Error node, |
| -- since we already gave the warning on the subprogram spec. |
| |
| if Raises_Constraint_Error (Actval) then |
| Rewrite (Actval, |
| Make_Raise_Constraint_Error (Loc, |
| Reason => CE_Range_Check_Failed)); |
| Set_Raises_Constraint_Error (Actval); |
| Set_Etype (Actval, Etype (F)); |
| end if; |
| |
| Assoc := |
| Make_Parameter_Association (Loc, |
| Explicit_Actual_Parameter => Actval, |
| Selector_Name => Make_Identifier (Loc, Chars (F))); |
| |
| -- Case of insertion is first named actual |
| |
| if No (Prev) or else |
| Nkind (Parent (Prev)) /= N_Parameter_Association |
| then |
| Set_Next_Named_Actual (Assoc, First_Named_Actual (N)); |
| Set_First_Named_Actual (N, Actval); |
| |
| if No (Prev) then |
| if not Present (Parameter_Associations (N)) then |
| Set_Parameter_Associations (N, New_List (Assoc)); |
| else |
| Append (Assoc, Parameter_Associations (N)); |
| end if; |
| |
| else |
| Insert_After (Prev, Assoc); |
| end if; |
| |
| -- Case of insertion is not first named actual |
| |
| else |
| Set_Next_Named_Actual |
| (Assoc, Next_Named_Actual (Parent (Prev))); |
| Set_Next_Named_Actual (Parent (Prev), Actval); |
| Append (Assoc, Parameter_Associations (N)); |
| end if; |
| |
| Mark_Rewrite_Insertion (Assoc); |
| Mark_Rewrite_Insertion (Actval); |
| |
| Prev := Actval; |
| end Insert_Default; |
| |
| ------------------- |
| -- Same_Ancestor -- |
| ------------------- |
| |
| function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is |
| FT1 : Entity_Id := T1; |
| FT2 : Entity_Id := T2; |
| |
| begin |
| if Is_Private_Type (T1) |
| and then Present (Full_View (T1)) |
| then |
| FT1 := Full_View (T1); |
| end if; |
| |
| if Is_Private_Type (T2) |
| and then Present (Full_View (T2)) |
| then |
| FT2 := Full_View (T2); |
| end if; |
| |
| return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2)); |
| end Same_Ancestor; |
| |
| -- Start of processing for Resolve_Actuals |
| |
| begin |
| A := First_Actual (N); |
| F := First_Formal (Nam); |
| |
| while Present (F) loop |
| if No (A) and then Needs_No_Actuals (Nam) then |
| null; |
| |
| -- If we have an error in any actual or formal, indicated by |
| -- a type of Any_Type, then abandon resolution attempt, and |
| -- set result type to Any_Type. |
| |
| elsif (Present (A) and then Etype (A) = Any_Type) |
| or else Etype (F) = Any_Type |
| then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| if Present (A) |
| and then (Nkind (Parent (A)) /= N_Parameter_Association |
| or else |
| Chars (Selector_Name (Parent (A))) = Chars (F)) |
| then |
| -- If the formal is Out or In_Out, do not resolve and expand the |
| -- conversion, because it is subsequently expanded into explicit |
| -- temporaries and assignments. However, the object of the |
| -- conversion can be resolved. An exception is the case of |
| -- a tagged type conversion with a class-wide actual. In that |
| -- case we want the tag check to occur and no temporary will |
| -- will be needed (no representation change can occur) and |
| -- the parameter is passed by reference, so we go ahead and |
| -- resolve the type conversion. |
| |
| if Ekind (F) /= E_In_Parameter |
| and then Nkind (A) = N_Type_Conversion |
| and then not Is_Class_Wide_Type (Etype (Expression (A))) |
| then |
| if Ekind (F) = E_In_Out_Parameter |
| and then Is_Array_Type (Etype (F)) |
| then |
| if Has_Aliased_Components (Etype (Expression (A))) |
| /= Has_Aliased_Components (Etype (F)) |
| then |
| Error_Msg_N |
| ("both component types in a view conversion must be" |
| & " aliased, or neither", A); |
| |
| elsif not Same_Ancestor (Etype (F), Etype (Expression (A))) |
| and then |
| (Is_By_Reference_Type (Etype (F)) |
| or else Is_By_Reference_Type (Etype (Expression (A)))) |
| then |
| Error_Msg_N |
| ("view conversion between unrelated by_reference " |
| & "array types not allowed (\A\I-00246)?", A); |
| end if; |
| end if; |
| |
| if Conversion_OK (A) |
| or else Valid_Conversion (A, Etype (A), Expression (A)) |
| then |
| Resolve (Expression (A)); |
| end if; |
| |
| else |
| if Nkind (A) = N_Type_Conversion |
| and then Is_Array_Type (Etype (F)) |
| and then not Same_Ancestor (Etype (F), Etype (Expression (A))) |
| and then |
| (Is_Limited_Type (Etype (F)) |
| or else Is_Limited_Type (Etype (Expression (A)))) |
| then |
| Error_Msg_N |
| ("Conversion between unrelated limited array types " |
| & "not allowed (\A\I-00246)?", A); |
| |
| -- Disable explanation (which produces additional errors) |
| -- until AI is approved and warning becomes an error. |
| |
| -- if Is_Limited_Type (Etype (F)) then |
| -- Explain_Limited_Type (Etype (F), A); |
| -- end if; |
| |
| -- if Is_Limited_Type (Etype (Expression (A))) then |
| -- Explain_Limited_Type (Etype (Expression (A)), A); |
| -- end if; |
| end if; |
| |
| Resolve (A, Etype (F)); |
| end if; |
| |
| A_Typ := Etype (A); |
| F_Typ := Etype (F); |
| |
| -- Perform error checks for IN and IN OUT parameters |
| |
| if Ekind (F) /= E_Out_Parameter then |
| |
| -- Check unset reference. For scalar parameters, it is clearly |
| -- wrong to pass an uninitialized value as either an IN or |
| -- IN-OUT parameter. For composites, it is also clearly an |
| -- error to pass a completely uninitialized value as an IN |
| -- parameter, but the case of IN OUT is trickier. We prefer |
| -- not to give a warning here. For example, suppose there is |
| -- a routine that sets some component of a record to False. |
| -- It is perfectly reasonable to make this IN-OUT and allow |
| -- either initialized or uninitialized records to be passed |
| -- in this case. |
| |
| -- For partially initialized composite values, we also avoid |
| -- warnings, since it is quite likely that we are passing a |
| -- partially initialized value and only the initialized fields |
| -- will in fact be read in the subprogram. |
| |
| if Is_Scalar_Type (A_Typ) |
| or else (Ekind (F) = E_In_Parameter |
| and then not Is_Partially_Initialized_Type (A_Typ)) |
| then |
| Check_Unset_Reference (A); |
| end if; |
| |
| -- In Ada 83 we cannot pass an OUT parameter as an IN |
| -- or IN OUT actual to a nested call, since this is a |
| -- case of reading an out parameter, which is not allowed. |
| |
| if Ada_83 |
| and then Is_Entity_Name (A) |
| and then Ekind (Entity (A)) = E_Out_Parameter |
| then |
| Error_Msg_N ("(Ada 83) illegal reading of out parameter", A); |
| end if; |
| end if; |
| |
| if Ekind (F) /= E_In_Parameter |
| and then not Is_OK_Variable_For_Out_Formal (A) |
| then |
| Error_Msg_NE ("actual for& must be a variable", A, F); |
| |
| if Is_Entity_Name (A) then |
| Kill_Checks (Entity (A)); |
| else |
| Kill_All_Checks; |
| end if; |
| end if; |
| |
| if Etype (A) = Any_Type then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Apply appropriate range checks for in, out, and in-out |
| -- parameters. Out and in-out parameters also need a separate |
| -- check, if there is a type conversion, to make sure the return |
| -- value meets the constraints of the variable before the |
| -- conversion. |
| |
| -- Gigi looks at the check flag and uses the appropriate types. |
| -- For now since one flag is used there is an optimization which |
| -- might not be done in the In Out case since Gigi does not do |
| -- any analysis. More thought required about this ??? |
| |
| if Ekind (F) = E_In_Parameter |
| or else Ekind (F) = E_In_Out_Parameter |
| then |
| if Is_Scalar_Type (Etype (A)) then |
| Apply_Scalar_Range_Check (A, F_Typ); |
| |
| elsif Is_Array_Type (Etype (A)) then |
| Apply_Length_Check (A, F_Typ); |
| |
| elsif Is_Record_Type (F_Typ) |
| and then Has_Discriminants (F_Typ) |
| and then Is_Constrained (F_Typ) |
| and then (not Is_Derived_Type (F_Typ) |
| or else Comes_From_Source (Nam)) |
| then |
| Apply_Discriminant_Check (A, F_Typ); |
| |
| elsif Is_Access_Type (F_Typ) |
| and then Is_Array_Type (Designated_Type (F_Typ)) |
| and then Is_Constrained (Designated_Type (F_Typ)) |
| then |
| Apply_Length_Check (A, F_Typ); |
| |
| elsif Is_Access_Type (F_Typ) |
| and then Has_Discriminants (Designated_Type (F_Typ)) |
| and then Is_Constrained (Designated_Type (F_Typ)) |
| then |
| Apply_Discriminant_Check (A, F_Typ); |
| |
| else |
| Apply_Range_Check (A, F_Typ); |
| end if; |
| end if; |
| |
| if Ekind (F) = E_Out_Parameter |
| or else Ekind (F) = E_In_Out_Parameter |
| then |
| if Nkind (A) = N_Type_Conversion then |
| if Is_Scalar_Type (A_Typ) then |
| Apply_Scalar_Range_Check |
| (Expression (A), Etype (Expression (A)), A_Typ); |
| else |
| Apply_Range_Check |
| (Expression (A), Etype (Expression (A)), A_Typ); |
| end if; |
| |
| else |
| if Is_Scalar_Type (F_Typ) then |
| Apply_Scalar_Range_Check (A, A_Typ, F_Typ); |
| |
| elsif Is_Array_Type (F_Typ) |
| and then Ekind (F) = E_Out_Parameter |
| then |
| Apply_Length_Check (A, F_Typ); |
| |
| else |
| Apply_Range_Check (A, A_Typ, F_Typ); |
| end if; |
| end if; |
| end if; |
| |
| -- An actual associated with an access parameter is implicitly |
| -- converted to the anonymous access type of the formal and |
| -- must satisfy the legality checks for access conversions. |
| |
| if Ekind (F_Typ) = E_Anonymous_Access_Type then |
| if not Valid_Conversion (A, F_Typ, A) then |
| Error_Msg_N |
| ("invalid implicit conversion for access parameter", A); |
| end if; |
| end if; |
| |
| -- Check bad case of atomic/volatile argument (RM C.6(12)) |
| |
| if Is_By_Reference_Type (Etype (F)) |
| and then Comes_From_Source (N) |
| then |
| if Is_Atomic_Object (A) |
| and then not Is_Atomic (Etype (F)) |
| then |
| Error_Msg_N |
| ("cannot pass atomic argument to non-atomic formal", |
| N); |
| |
| elsif Is_Volatile_Object (A) |
| and then not Is_Volatile (Etype (F)) |
| then |
| Error_Msg_N |
| ("cannot pass volatile argument to non-volatile formal", |
| N); |
| end if; |
| end if; |
| |
| -- Check that subprograms don't have improper controlling |
| -- arguments (RM 3.9.2 (9)) |
| |
| if Is_Controlling_Formal (F) then |
| Set_Is_Controlling_Actual (A); |
| elsif Nkind (A) = N_Explicit_Dereference then |
| Validate_Remote_Access_To_Class_Wide_Type (A); |
| end if; |
| |
| if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A)) |
| and then not Is_Class_Wide_Type (F_Typ) |
| and then not Is_Controlling_Formal (F) |
| then |
| Error_Msg_N ("class-wide argument not allowed here!", A); |
| |
| if Is_Subprogram (Nam) |
| and then Comes_From_Source (Nam) |
| then |
| Error_Msg_Node_2 := F_Typ; |
| Error_Msg_NE |
| ("& is not a primitive operation of &!", A, Nam); |
| end if; |
| |
| elsif Is_Access_Type (A_Typ) |
| and then Is_Access_Type (F_Typ) |
| and then Ekind (F_Typ) /= E_Access_Subprogram_Type |
| and then (Is_Class_Wide_Type (Designated_Type (A_Typ)) |
| or else (Nkind (A) = N_Attribute_Reference |
| and then |
| Is_Class_Wide_Type (Etype (Prefix (A))))) |
| and then not Is_Class_Wide_Type (Designated_Type (F_Typ)) |
| and then not Is_Controlling_Formal (F) |
| then |
| Error_Msg_N |
| ("access to class-wide argument not allowed here!", A); |
| |
| if Is_Subprogram (Nam) |
| and then Comes_From_Source (Nam) |
| then |
| Error_Msg_Node_2 := Designated_Type (F_Typ); |
| Error_Msg_NE |
| ("& is not a primitive operation of &!", A, Nam); |
| end if; |
| end if; |
| |
| Eval_Actual (A); |
| |
| -- If it is a named association, treat the selector_name as |
| -- a proper identifier, and mark the corresponding entity. |
| |
| if Nkind (Parent (A)) = N_Parameter_Association then |
| Set_Entity (Selector_Name (Parent (A)), F); |
| Generate_Reference (F, Selector_Name (Parent (A))); |
| Set_Etype (Selector_Name (Parent (A)), F_Typ); |
| Generate_Reference (F_Typ, N, ' '); |
| end if; |
| |
| Prev := A; |
| |
| if Ekind (F) /= E_Out_Parameter then |
| Check_Unset_Reference (A); |
| end if; |
| |
| Next_Actual (A); |
| |
| -- Case where actual is not present |
| |
| else |
| Insert_Default; |
| end if; |
| |
| Next_Formal (F); |
| end loop; |
| end Resolve_Actuals; |
| |
| ----------------------- |
| -- Resolve_Allocator -- |
| ----------------------- |
| |
| procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is |
| E : constant Node_Id := Expression (N); |
| Subtyp : Entity_Id; |
| Discrim : Entity_Id; |
| Constr : Node_Id; |
| Disc_Exp : Node_Id; |
| |
| function In_Dispatching_Context return Boolean; |
| -- If the allocator is an actual in a call, it is allowed to be |
| -- class-wide when the context is not because it is a controlling |
| -- actual. |
| |
| ---------------------------- |
| -- In_Dispatching_Context -- |
| ---------------------------- |
| |
| function In_Dispatching_Context return Boolean is |
| Par : constant Node_Id := Parent (N); |
| |
| begin |
| return (Nkind (Par) = N_Function_Call |
| or else Nkind (Par) = N_Procedure_Call_Statement) |
| and then Is_Entity_Name (Name (Par)) |
| and then Is_Dispatching_Operation (Entity (Name (Par))); |
| end In_Dispatching_Context; |
| |
| -- Start of processing for Resolve_Allocator |
| |
| begin |
| -- Replace general access with specific type |
| |
| if Ekind (Etype (N)) = E_Allocator_Type then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| if Is_Abstract (Typ) then |
| Error_Msg_N ("type of allocator cannot be abstract", N); |
| end if; |
| |
| -- For qualified expression, resolve the expression using the |
| -- given subtype (nothing to do for type mark, subtype indication) |
| |
| if Nkind (E) = N_Qualified_Expression then |
| if Is_Class_Wide_Type (Etype (E)) |
| and then not Is_Class_Wide_Type (Designated_Type (Typ)) |
| and then not In_Dispatching_Context |
| then |
| Error_Msg_N |
| ("class-wide allocator not allowed for this access type", N); |
| end if; |
| |
| Resolve (Expression (E), Etype (E)); |
| Check_Unset_Reference (Expression (E)); |
| |
| -- A qualified expression requires an exact match of the type, |
| -- class-wide matching is not allowed. |
| |
| if (Is_Class_Wide_Type (Etype (Expression (E))) |
| or else Is_Class_Wide_Type (Etype (E))) |
| and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E)) |
| then |
| Wrong_Type (Expression (E), Etype (E)); |
| end if; |
| |
| -- For a subtype mark or subtype indication, freeze the subtype |
| |
| else |
| Freeze_Expression (E); |
| |
| if Is_Access_Constant (Typ) and then not No_Initialization (N) then |
| Error_Msg_N |
| ("initialization required for access-to-constant allocator", N); |
| end if; |
| |
| -- A special accessibility check is needed for allocators that |
| -- constrain access discriminants. The level of the type of the |
| -- expression used to contrain an access discriminant cannot be |
| -- deeper than the type of the allocator (in constrast to access |
| -- parameters, where the level of the actual can be arbitrary). |
| -- We can't use Valid_Conversion to perform this check because |
| -- in general the type of the allocator is unrelated to the type |
| -- of the access discriminant. Note that specialized checks are |
| -- needed for the cases of a constraint expression which is an |
| -- access attribute or an access discriminant. |
| |
| if Nkind (Original_Node (E)) = N_Subtype_Indication |
| and then Ekind (Typ) /= E_Anonymous_Access_Type |
| then |
| Subtyp := Entity (Subtype_Mark (Original_Node (E))); |
| |
| if Has_Discriminants (Subtyp) then |
| Discrim := First_Discriminant (Base_Type (Subtyp)); |
| Constr := First (Constraints (Constraint (Original_Node (E)))); |
| |
| while Present (Discrim) and then Present (Constr) loop |
| if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then |
| if Nkind (Constr) = N_Discriminant_Association then |
| Disc_Exp := Original_Node (Expression (Constr)); |
| else |
| Disc_Exp := Original_Node (Constr); |
| end if; |
| |
| if Type_Access_Level (Etype (Disc_Exp)) |
| > Type_Access_Level (Typ) |
| then |
| Error_Msg_N |
| ("operand type has deeper level than allocator type", |
| Disc_Exp); |
| |
| elsif Nkind (Disc_Exp) = N_Attribute_Reference |
| and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) |
| = Attribute_Access |
| and then Object_Access_Level (Prefix (Disc_Exp)) |
| > Type_Access_Level (Typ) |
| then |
| Error_Msg_N |
| ("prefix of attribute has deeper level than" |
| & " allocator type", Disc_Exp); |
| |
| -- When the operand is an access discriminant the check |
| -- is against the level of the prefix object. |
| |
| elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type |
| and then Nkind (Disc_Exp) = N_Selected_Component |
| and then Object_Access_Level (Prefix (Disc_Exp)) |
| > Type_Access_Level (Typ) |
| then |
| Error_Msg_N |
| ("access discriminant has deeper level than" |
| & " allocator type", Disc_Exp); |
| end if; |
| end if; |
| Next_Discriminant (Discrim); |
| Next (Constr); |
| end loop; |
| end if; |
| end if; |
| end if; |
| |
| -- Check for allocation from an empty storage pool |
| |
| if No_Pool_Assigned (Typ) then |
| declare |
| Loc : constant Source_Ptr := Sloc (N); |
| |
| begin |
| Error_Msg_N ("?allocation from empty storage pool!", N); |
| Error_Msg_N ("?Storage_Error will be raised at run time!", N); |
| Insert_Action (N, |
| Make_Raise_Storage_Error (Loc, |
| Reason => SE_Empty_Storage_Pool)); |
| end; |
| end if; |
| end Resolve_Allocator; |
| |
| --------------------------- |
| -- Resolve_Arithmetic_Op -- |
| --------------------------- |
| |
| -- Used for resolving all arithmetic operators except exponentiation |
| |
| procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| TL : constant Entity_Id := Base_Type (Etype (L)); |
| TR : constant Entity_Id := Base_Type (Etype (R)); |
| T : Entity_Id; |
| Rop : Node_Id; |
| |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions always are of the base type, not a subtype of it. |
| |
| function Is_Integer_Or_Universal (N : Node_Id) return Boolean; |
| -- Return True iff given type is Integer or universal real/integer |
| |
| procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id); |
| -- Choose type of integer literal in fixed-point operation to conform |
| -- to available fixed-point type. T is the type of the other operand, |
| -- which is needed to determine the expected type of N. |
| |
| procedure Set_Operand_Type (N : Node_Id); |
| -- Set operand type to T if universal |
| |
| ----------------------------- |
| -- Is_Integer_Or_Universal -- |
| ----------------------------- |
| |
| function Is_Integer_Or_Universal (N : Node_Id) return Boolean is |
| T : Entity_Id; |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| if not Is_Overloaded (N) then |
| T := Etype (N); |
| return Base_Type (T) = Base_Type (Standard_Integer) |
| or else T = Universal_Integer |
| or else T = Universal_Real; |
| else |
| Get_First_Interp (N, Index, It); |
| |
| while Present (It.Typ) loop |
| |
| if Base_Type (It.Typ) = Base_Type (Standard_Integer) |
| or else It.Typ = Universal_Integer |
| or else It.Typ = Universal_Real |
| then |
| return True; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| end if; |
| |
| return False; |
| end Is_Integer_Or_Universal; |
| |
| ---------------------------- |
| -- Set_Mixed_Mode_Operand -- |
| ---------------------------- |
| |
| procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is |
| Index : Interp_Index; |
| It : Interp; |
| |
| begin |
| if Universal_Interpretation (N) = Universal_Integer then |
| |
| -- A universal integer literal is resolved as standard integer |
| -- except in the case of a fixed-point result, where we leave |
| -- it as universal (to be handled by Exp_Fixd later on) |
| |
| if Is_Fixed_Point_Type (T) then |
| Resolve (N, Universal_Integer); |
| else |
| Resolve (N, Standard_Integer); |
| end if; |
| |
| elsif Universal_Interpretation (N) = Universal_Real |
| and then (T = Base_Type (Standard_Integer) |
| or else T = Universal_Integer |
| or else T = Universal_Real) |
| then |
| -- A universal real can appear in a fixed-type context. We resolve |
| -- the literal with that context, even though this might raise an |
| -- exception prematurely (the other operand may be zero). |
| |
| Resolve (N, B_Typ); |
| |
| elsif Etype (N) = Base_Type (Standard_Integer) |
| and then T = Universal_Real |
| and then Is_Overloaded (N) |
| then |
| -- Integer arg in mixed-mode operation. Resolve with universal |
| -- type, in case preference rule must be applied. |
| |
| Resolve (N, Universal_Integer); |
| |
| elsif Etype (N) = T |
| and then B_Typ /= Universal_Fixed |
| then |
| -- Not a mixed-mode operation. Resolve with context. |
| |
| Resolve (N, B_Typ); |
| |
| elsif Etype (N) = Any_Fixed then |
| |
| -- N may itself be a mixed-mode operation, so use context type. |
| |
| Resolve (N, B_Typ); |
| |
| elsif Is_Fixed_Point_Type (T) |
| and then B_Typ = Universal_Fixed |
| and then Is_Overloaded (N) |
| then |
| -- Must be (fixed * fixed) operation, operand must have one |
| -- compatible interpretation. |
| |
| Resolve (N, Any_Fixed); |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (T = Universal_Real |
| or else Is_Fixed_Point_Type (T)) |
| and then Is_Overloaded (N) |
| then |
| -- C * F(X) in a fixed context, where C is a real literal or a |
| -- fixed-point expression. F must have either a fixed type |
| -- interpretation or an integer interpretation, but not both. |
| |
| Get_First_Interp (N, Index, It); |
| |
| while Present (It.Typ) loop |
| if Base_Type (It.Typ) = Base_Type (Standard_Integer) then |
| |
| if Analyzed (N) then |
| Error_Msg_N ("ambiguous operand in fixed operation", N); |
| else |
| Resolve (N, Standard_Integer); |
| end if; |
| |
| elsif Is_Fixed_Point_Type (It.Typ) then |
| |
| if Analyzed (N) then |
| Error_Msg_N ("ambiguous operand in fixed operation", N); |
| else |
| Resolve (N, It.Typ); |
| end if; |
| end if; |
| |
| Get_Next_Interp (Index, It); |
| end loop; |
| |
| -- Reanalyze the literal with the fixed type of the context. |
| |
| if N = L then |
| Set_Analyzed (R, False); |
| Resolve (R, B_Typ); |
| else |
| Set_Analyzed (L, False); |
| Resolve (L, B_Typ); |
| end if; |
| |
| else |
| Resolve (N); |
| end if; |
| end Set_Mixed_Mode_Operand; |
| |
| ---------------------- |
| -- Set_Operand_Type -- |
| ---------------------- |
| |
| procedure Set_Operand_Type (N : Node_Id) is |
| begin |
| if Etype (N) = Universal_Integer |
| or else Etype (N) = Universal_Real |
| then |
| Set_Etype (N, T); |
| end if; |
| end Set_Operand_Type; |
| |
| -- Start of processing for Resolve_Arithmetic_Op |
| |
| begin |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Operator (N, Typ); |
| return; |
| |
| -- Special-case for mixed-mode universal expressions or fixed point |
| -- type operation: each argument is resolved separately. The same |
| -- treatment is required if one of the operands of a fixed point |
| -- operation is universal real, since in this case we don't do a |
| -- conversion to a specific fixed-point type (instead the expander |
| -- takes care of the case). |
| |
| elsif (B_Typ = Universal_Integer |
| or else B_Typ = Universal_Real) |
| and then Present (Universal_Interpretation (L)) |
| and then Present (Universal_Interpretation (R)) |
| then |
| Resolve (L, Universal_Interpretation (L)); |
| Resolve (R, Universal_Interpretation (R)); |
| Set_Etype (N, B_Typ); |
| |
| elsif (B_Typ = Universal_Real |
| or else Etype (N) = Universal_Fixed |
| or else (Etype (N) = Any_Fixed |
| and then Is_Fixed_Point_Type (B_Typ)) |
| or else (Is_Fixed_Point_Type (B_Typ) |
| and then (Is_Integer_Or_Universal (L) |
| or else |
| Is_Integer_Or_Universal (R)))) |
| and then (Nkind (N) = N_Op_Multiply or else |
| Nkind (N) = N_Op_Divide) |
| then |
| if TL = Universal_Integer or else TR = Universal_Integer then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- If context is a fixed type and one operand is integer, the |
| -- other is resolved with the type of the context. |
| |
| if Is_Fixed_Point_Type (B_Typ) |
| and then (Base_Type (TL) = Base_Type (Standard_Integer) |
| or else TL = Universal_Integer) |
| then |
| Resolve (R, B_Typ); |
| Resolve (L, TL); |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (Base_Type (TR) = Base_Type (Standard_Integer) |
| or else TR = Universal_Integer) |
| then |
| Resolve (L, B_Typ); |
| Resolve (R, TR); |
| |
| else |
| Set_Mixed_Mode_Operand (L, TR); |
| Set_Mixed_Mode_Operand (R, TL); |
| end if; |
| |
| if Etype (N) = Universal_Fixed |
| or else Etype (N) = Any_Fixed |
| then |
| if B_Typ = Universal_Fixed |
| and then Nkind (Parent (N)) /= N_Type_Conversion |
| and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion |
| then |
| Error_Msg_N |
| ("type cannot be determined from context!", N); |
| Error_Msg_N |
| ("\explicit conversion to result type required", N); |
| |
| Set_Etype (L, Any_Type); |
| Set_Etype (R, Any_Type); |
| |
| else |
| if Ada_83 |
| and then Etype (N) = Universal_Fixed |
| and then Nkind (Parent (N)) /= N_Type_Conversion |
| and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion |
| then |
| Error_Msg_N |
| ("(Ada 83) fixed-point operation " & |
| "needs explicit conversion", |
| N); |
| end if; |
| |
| Set_Etype (N, B_Typ); |
| end if; |
| |
| elsif Is_Fixed_Point_Type (B_Typ) |
| and then (Is_Integer_Or_Universal (L) |
| or else Nkind (L) = N_Real_Literal |
| or else Nkind (R) = N_Real_Literal |
| or else |
| Is_Integer_Or_Universal (R)) |
| then |
| Set_Etype (N, B_Typ); |
| |
| elsif Etype (N) = Any_Fixed then |
| |
| -- If no previous errors, this is only possible if one operand |
| -- is overloaded and the context is universal. Resolve as such. |
| |
| Set_Etype (N, B_Typ); |
| end if; |
| |
| else |
| if (TL = Universal_Integer or else TL = Universal_Real) |
| and then (TR = Universal_Integer or else TR = Universal_Real) |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- If the context is Universal_Fixed and the operands are also |
| -- universal fixed, this is an error, unless there is only one |
| -- applicable fixed_point type (usually duration). |
| |
| if B_Typ = Universal_Fixed |
| and then Etype (L) = Universal_Fixed |
| then |
| T := Unique_Fixed_Point_Type (N); |
| |
| if T = Any_Type then |
| Set_Etype (N, T); |
| return; |
| else |
| Resolve (L, T); |
| Resolve (R, T); |
| end if; |
| |
| else |
| Resolve (L, B_Typ); |
| Resolve (R, B_Typ); |
| end if; |
| |
| -- If one of the arguments was resolved to a non-universal type. |
| -- label the result of the operation itself with the same type. |
| -- Do the same for the universal argument, if any. |
| |
| T := Intersect_Types (L, R); |
| Set_Etype (N, Base_Type (T)); |
| Set_Operand_Type (L); |
| Set_Operand_Type (R); |
| end if; |
| |
| Generate_Operator_Reference (N, Typ); |
| Eval_Arithmetic_Op (N); |
| |
| -- Set overflow and division checking bit. Much cleverer code needed |
| -- here eventually and perhaps the Resolve routines should be separated |
| -- for the various arithmetic operations, since they will need |
| -- different processing. ??? |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| |
| -- Give warning if explicit division by zero |
| |
| if (Nkind (N) = N_Op_Divide |
| or else Nkind (N) = N_Op_Rem |
| or else Nkind (N) = N_Op_Mod) |
| and then not Division_Checks_Suppressed (Etype (N)) |
| then |
| Rop := Right_Opnd (N); |
| |
| if Compile_Time_Known_Value (Rop) |
| and then ((Is_Integer_Type (Etype (Rop)) |
| and then Expr_Value (Rop) = Uint_0) |
| or else |
| (Is_Real_Type (Etype (Rop)) |
| and then Expr_Value_R (Rop) = Ureal_0)) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "division by zero?", CE_Divide_By_Zero, |
| Loc => Sloc (Right_Opnd (N))); |
| |
| -- Otherwise just set the flag to check at run time |
| |
| else |
| Set_Do_Division_Check (N); |
| end if; |
| end if; |
| end if; |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| end Resolve_Arithmetic_Op; |
| |
| ------------------ |
| -- Resolve_Call -- |
| ------------------ |
| |
| procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Subp : constant Node_Id := Name (N); |
| Nam : Entity_Id; |
| I : Interp_Index; |
| It : Interp; |
| Norm_OK : Boolean; |
| Scop : Entity_Id; |
| Decl : Node_Id; |
| |
| begin |
| -- The context imposes a unique interpretation with type Typ on |
| -- a procedure or function call. Find the entity of the subprogram |
| -- that yields the expected type, and propagate the corresponding |
| -- formal constraints on the actuals. The caller has established |
| -- that an interpretation exists, and emitted an error if not unique. |
| |
| -- First deal with the case of a call to an access-to-subprogram, |
| -- dereference made explicit in Analyze_Call. |
| |
| if Ekind (Etype (Subp)) = E_Subprogram_Type then |
| if not Is_Overloaded (Subp) then |
| Nam := Etype (Subp); |
| |
| else |
| -- Find the interpretation whose type (a subprogram type) |
| -- has a return type that is compatible with the context. |
| -- Analysis of the node has established that one exists. |
| |
| Get_First_Interp (Subp, I, It); |
| Nam := Empty; |
| |
| while Present (It.Typ) loop |
| if Covers (Typ, Etype (It.Typ)) then |
| Nam := It.Typ; |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| if No (Nam) then |
| raise Program_Error; |
| end if; |
| end if; |
| |
| -- If the prefix is not an entity, then resolve it |
| |
| if not Is_Entity_Name (Subp) then |
| Resolve (Subp, Nam); |
| end if; |
| |
| -- For an indirect call, we always invalidate checks, since we |
| -- do not know whether the subprogram is local or global. Yes |
| -- we could do better here, e.g. by knowing that there are no |
| -- local subprograms, but it does not seem worth the effort. |
| -- Similarly, we kill al knowledge of current constant values. |
| |
| Kill_Current_Values; |
| |
| -- If this is a procedure call which is really an entry call, do |
| -- the conversion of the procedure call to an entry call. Protected |
| -- operations use the same circuitry because the name in the call |
| -- can be an arbitrary expression with special resolution rules. |
| |
| elsif Nkind (Subp) = N_Selected_Component |
| or else Nkind (Subp) = N_Indexed_Component |
| or else (Is_Entity_Name (Subp) |
| and then Ekind (Entity (Subp)) = E_Entry) |
| then |
| Resolve_Entry_Call (N, Typ); |
| Check_Elab_Call (N); |
| |
| -- Kill checks and constant values, as above for indirect case |
| -- Who knows what happens when another task is activated? |
| |
| Kill_Current_Values; |
| return; |
| |
| -- Normal subprogram call with name established in Resolve |
| |
| elsif not (Is_Type (Entity (Subp))) then |
| Nam := Entity (Subp); |
| Set_Entity_With_Style_Check (Subp, Nam); |
| Generate_Reference (Nam, Subp); |
| |
| -- Otherwise we must have the case of an overloaded call |
| |
| else |
| pragma Assert (Is_Overloaded (Subp)); |
| Nam := Empty; -- We know that it will be assigned in loop below. |
| |
| Get_First_Interp (Subp, I, It); |
| |
| while Present (It.Typ) loop |
| if Covers (Typ, It.Typ) then |
| Nam := It.Nam; |
| Set_Entity_With_Style_Check (Subp, Nam); |
| Generate_Reference (Nam, Subp); |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end if; |
| |
| -- Check that a call to Current_Task does not occur in an entry body |
| |
| if Is_RTE (Nam, RE_Current_Task) then |
| declare |
| P : Node_Id; |
| |
| begin |
| P := N; |
| loop |
| P := Parent (P); |
| exit when No (P); |
| |
| if Nkind (P) = N_Entry_Body then |
| Error_Msg_NE |
| ("& should not be used in entry body ('R'M C.7(17))", |
| N, Nam); |
| exit; |
| end if; |
| end loop; |
| end; |
| end if; |
| |
| -- Cannot call thread body directly |
| |
| if Is_Thread_Body (Nam) then |
| Error_Msg_N ("cannot call thread body directly", N); |
| end if; |
| |
| -- If the subprogram is not global, then kill all checks. This is |
| -- a bit conservative, since in many cases we could do better, but |
| -- it is not worth the effort. Similarly, we kill constant values. |
| -- However we do not need to do this for internal entities (unless |
| -- they are inherited user-defined subprograms), since they are not |
| -- in the business of molesting global values. |
| |
| if not Is_Library_Level_Entity (Nam) |
| and then (Comes_From_Source (Nam) |
| or else (Present (Alias (Nam)) |
| and then Comes_From_Source (Alias (Nam)))) |
| then |
| Kill_Current_Values; |
| end if; |
| |
| -- Check for call to obsolescent subprogram |
| |
| if Warn_On_Obsolescent_Feature then |
| Decl := Parent (Parent (Nam)); |
| |
| if Nkind (Decl) = N_Subprogram_Declaration |
| and then Is_List_Member (Decl) |
| and then Nkind (Next (Decl)) = N_Pragma |
| then |
| declare |
| P : constant Node_Id := Next (Decl); |
| |
| begin |
| if Chars (P) = Name_Obsolescent then |
| Error_Msg_NE ("call to obsolescent subprogram&?", N, Nam); |
| |
| if Pragma_Argument_Associations (P) /= No_List then |
| Name_Buffer (1) := '|'; |
| Name_Buffer (2) := '?'; |
| Name_Len := 2; |
| Add_String_To_Name_Buffer |
| (Strval (Expression |
| (First (Pragma_Argument_Associations (P))))); |
| Error_Msg_N (Name_Buffer (1 .. Name_Len), N); |
| end if; |
| end if; |
| end; |
| end if; |
| end if; |
| |
| -- Check that a procedure call does not occur in the context |
| -- of the entry call statement of a conditional or timed |
| -- entry call. Note that the case of a call to a subprogram |
| -- renaming of an entry will also be rejected. The test |
| -- for N not being an N_Entry_Call_Statement is defensive, |
| -- covering the possibility that the processing of entry |
| -- calls might reach this point due to later modifications |
| -- of the code above. |
| |
| if Nkind (Parent (N)) = N_Entry_Call_Alternative |
| and then Nkind (N) /= N_Entry_Call_Statement |
| and then Entry_Call_Statement (Parent (N)) = N |
| then |
| Error_Msg_N ("entry call required in select statement", N); |
| end if; |
| |
| -- Check that this is not a call to a protected procedure or |
| -- entry from within a protected function. |
| |
| if Ekind (Current_Scope) = E_Function |
| and then Ekind (Scope (Current_Scope)) = E_Protected_Type |
| and then Ekind (Nam) /= E_Function |
| and then Scope (Nam) = Scope (Current_Scope) |
| then |
| Error_Msg_N ("within protected function, protected " & |
| "object is constant", N); |
| Error_Msg_N ("\cannot call operation that may modify it", N); |
| end if; |
| |
| -- Freeze the subprogram name if not in default expression. Note |
| -- that we freeze procedure calls as well as function calls. |
| -- Procedure calls are not frozen according to the rules (RM |
| -- 13.14(14)) because it is impossible to have a procedure call to |
| -- a non-frozen procedure in pure Ada, but in the code that we |
| -- generate in the expander, this rule needs extending because we |
| -- can generate procedure calls that need freezing. |
| |
| if Is_Entity_Name (Subp) and then not In_Default_Expression then |
| Freeze_Expression (Subp); |
| end if; |
| |
| -- For a predefined operator, the type of the result is the type |
| -- imposed by context, except for a predefined operation on universal |
| -- fixed. Otherwise The type of the call is the type returned by the |
| -- subprogram being called. |
| |
| if Is_Predefined_Op (Nam) then |
| if Etype (N) /= Universal_Fixed then |
| Set_Etype (N, Typ); |
| end if; |
| |
| -- If the subprogram returns an array type, and the context |
| -- requires the component type of that array type, the node is |
| -- really an indexing of the parameterless call. Resolve as such. |
| -- A pathological case occurs when the type of the component is |
| -- an access to the array type. In this case the call is truly |
| -- ambiguous. |
| |
| elsif Needs_No_Actuals (Nam) |
| and then |
| ((Is_Array_Type (Etype (Nam)) |
| and then Covers (Typ, Component_Type (Etype (Nam)))) |
| or else (Is_Access_Type (Etype (Nam)) |
| and then Is_Array_Type (Designated_Type (Etype (Nam))) |
| and then |
| Covers (Typ, |
| Component_Type (Designated_Type (Etype (Nam)))))) |
| then |
| declare |
| Index_Node : Node_Id; |
| New_Subp : Node_Id; |
| Ret_Type : constant Entity_Id := Etype (Nam); |
| |
| begin |
| if Is_Access_Type (Ret_Type) |
| and then Ret_Type = Component_Type (Designated_Type (Ret_Type)) |
| then |
| Error_Msg_N |
| ("cannot disambiguate function call and indexing", N); |
| else |
| New_Subp := Relocate_Node (Subp); |
| Set_Entity (Subp, Nam); |
| |
| if Component_Type (Ret_Type) /= Any_Type then |
| Index_Node := |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Function_Call (Loc, |
| Name => New_Subp), |
| Expressions => Parameter_Associations (N)); |
| |
| -- Since we are correcting a node classification error made |
| -- by the parser, we call Replace rather than Rewrite. |
| |
| Replace (N, Index_Node); |
| Set_Etype (Prefix (N), Ret_Type); |
| Set_Etype (N, Typ); |
| Resolve_Indexed_Component (N, Typ); |
| Check_Elab_Call (Prefix (N)); |
| end if; |
| end if; |
| |
| return; |
| end; |
| |
| else |
| Set_Etype (N, Etype (Nam)); |
| end if; |
| |
| -- In the case where the call is to an overloaded subprogram, Analyze |
| -- calls Normalize_Actuals once per overloaded subprogram. Therefore in |
| -- such a case Normalize_Actuals needs to be called once more to order |
| -- the actuals correctly. Otherwise the call will have the ordering |
| -- given by the last overloaded subprogram whether this is the correct |
| -- one being called or not. |
| |
| if Is_Overloaded (Subp) then |
| Normalize_Actuals (N, Nam, False, Norm_OK); |
| pragma Assert (Norm_OK); |
| end if; |
| |
| -- In any case, call is fully resolved now. Reset Overload flag, to |
| -- prevent subsequent overload resolution if node is analyzed again |
| |
| Set_Is_Overloaded (Subp, False); |
| Set_Is_Overloaded (N, False); |
| |
| -- If we are calling the current subprogram from immediately within |
| -- its body, then that is the case where we can sometimes detect |
| -- cases of infinite recursion statically. Do not try this in case |
| -- restriction No_Recursion is in effect anyway. |
| |
| Scop := Current_Scope; |
| |
| if Nam = Scop |
| and then not Restrictions (No_Recursion) |
| and then Check_Infinite_Recursion (N) |
| then |
| -- Here we detected and flagged an infinite recursion, so we do |
| -- not need to test the case below for further warnings. |
| |
| null; |
| |
| -- If call is to immediately containing subprogram, then check for |
| -- the case of a possible run-time detectable infinite recursion. |
| |
| else |
| while Scop /= Standard_Standard loop |
| if Nam = Scop then |
| -- Although in general recursion is not statically checkable, |
| -- the case of calling an immediately containing subprogram |
| -- is easy to catch. |
| |
| Check_Restriction (No_Recursion, N); |
| |
| -- If the recursive call is to a parameterless procedure, then |
| -- even if we can't statically detect infinite recursion, this |
| -- is pretty suspicious, and we output a warning. Furthermore, |
| -- we will try later to detect some cases here at run time by |
| -- expanding checking code (see Detect_Infinite_Recursion in |
| -- package Exp_Ch6). |
| -- If the recursive call is within a handler we do not emit a |
| -- warning, because this is a common idiom: loop until input |
| -- is correct, catch illegal input in handler and restart. |
| |
| if No (First_Formal (Nam)) |
| and then Etype (Nam) = Standard_Void_Type |
| and then not Error_Posted (N) |
| and then Nkind (Parent (N)) /= N_Exception_Handler |
| then |
| Set_Has_Recursive_Call (Nam); |
| Error_Msg_N ("possible infinite recursion?", N); |
| Error_Msg_N ("Storage_Error may be raised at run time?", N); |
| end if; |
| |
| exit; |
| end if; |
| |
| Scop := Scope (Scop); |
| end loop; |
| end if; |
| |
| -- If subprogram name is a predefined operator, it was given in |
| -- functional notation. Replace call node with operator node, so |
| -- that actuals can be resolved appropriately. |
| |
| if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then |
| Make_Call_Into_Operator (N, Typ, Entity (Name (N))); |
| return; |
| |
| elsif Present (Alias (Nam)) |
| and then Is_Predefined_Op (Alias (Nam)) |
| then |
| Resolve_Actuals (N, Nam); |
| Make_Call_Into_Operator (N, Typ, Alias (Nam)); |
| return; |
| end if; |
| |
| -- Create a transient scope if the resulting type requires it |
| |
| -- There are 3 notable exceptions: in init procs, the transient scope |
| -- overhead is not needed and even incorrect due to the actual expansion |
| -- of adjust calls; the second case is enumeration literal pseudo calls, |
| -- the other case is intrinsic subprograms (Unchecked_Conversion and |
| -- source information functions) that do not use the secondary stack |
| -- even though the return type is unconstrained. |
| |
| -- If this is an initialization call for a type whose initialization |
| -- uses the secondary stack, we also need to create a transient scope |
| -- for it, precisely because we will not do it within the init proc |
| -- itself. |
| |
| if Expander_Active |
| and then Is_Type (Etype (Nam)) |
| and then Requires_Transient_Scope (Etype (Nam)) |
| and then Ekind (Nam) /= E_Enumeration_Literal |
| and then not Within_Init_Proc |
| and then not Is_Intrinsic_Subprogram (Nam) |
| then |
| Establish_Transient_Scope |
| (N, Sec_Stack => not Functions_Return_By_DSP_On_Target); |
| |
| -- If the call appears within the bounds of a loop, it will |
| -- be rewritten and reanalyzed, nothing left to do here. |
| |
| if Nkind (N) /= N_Function_Call then |
| return; |
| end if; |
| |
| elsif Is_Init_Proc (Nam) |
| and then not Within_Init_Proc |
| then |
| Check_Initialization_Call (N, Nam); |
| end if; |
| |
| -- A protected function cannot be called within the definition of the |
| -- enclosing protected type. |
| |
| if Is_Protected_Type (Scope (Nam)) |
| and then In_Open_Scopes (Scope (Nam)) |
| and then not Has_Completion (Scope (Nam)) |
| then |
| Error_Msg_NE |
| ("& cannot be called before end of protected definition", N, Nam); |
| end if; |
| |
| -- Propagate interpretation to actuals, and add default expressions |
| -- where needed. |
| |
| if Present (First_Formal (Nam)) then |
| Resolve_Actuals (N, Nam); |
| |
| -- Overloaded literals are rewritten as function calls, for |
| -- purpose of resolution. After resolution, we can replace |
| -- the call with the literal itself. |
| |
| elsif Ekind (Nam) = E_Enumeration_Literal then |
| Copy_Node (Subp, N); |
| Resolve_Entity_Name (N, Typ); |
| |
| -- Avoid validation, since it is a static function call |
| |
| return; |
| end if; |
| |
| -- If the subprogram is a primitive operation, check whether or not |
| -- it is a correct dispatching call. |
| |
| if Is_Overloadable (Nam) |
| and then Is_Dispatching_Operation (Nam) |
| then |
| Check_Dispatching_Call (N); |
| |
| elsif Is_Abstract (Nam) |
| and then not In_Instance |
| then |
| Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam); |
| end if; |
| |
| if Is_Intrinsic_Subprogram (Nam) then |
| Check_Intrinsic_Call (N); |
| end if; |
| |
| -- If we fall through we definitely have a non-static call |
| |
| Check_Elab_Call (N); |
| end Resolve_Call; |
| |
| ------------------------------- |
| -- Resolve_Character_Literal -- |
| ------------------------------- |
| |
| procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| C : Entity_Id; |
| |
| begin |
| -- Verify that the character does belong to the type of the context |
| |
| Set_Etype (N, B_Typ); |
| Eval_Character_Literal (N); |
| |
| -- Wide_Character literals must always be defined, since the set of |
| -- wide character literals is complete, i.e. if a character literal |
| -- is accepted by the parser, then it is OK for wide character. |
| |
| if Root_Type (B_Typ) = Standard_Wide_Character then |
| return; |
| |
| -- Always accept character literal for type Any_Character, which |
| -- occurs in error situations and in comparisons of literals, both |
| -- of which should accept all literals. |
| |
| elsif B_Typ = Any_Character then |
| return; |
| |
| -- For Standard.Character or a type derived from it, check that |
| -- the literal is in range |
| |
| elsif Root_Type (B_Typ) = Standard_Character then |
| if In_Character_Range (Char_Literal_Value (N)) then |
| return; |
| end if; |
| |
| -- If the entity is already set, this has already been resolved in |
| -- a generic context, or comes from expansion. Nothing else to do. |
| |
| elsif Present (Entity (N)) then |
| return; |
| |
| -- Otherwise we have a user defined character type, and we can use |
| -- the standard visibility mechanisms to locate the referenced entity |
| |
| else |
| C := Current_Entity (N); |
| |
| while Present (C) loop |
| if Etype (C) = B_Typ then |
| Set_Entity_With_Style_Check (N, C); |
| Generate_Reference (C, N); |
| return; |
| end if; |
| |
| C := Homonym (C); |
| end loop; |
| end if; |
| |
| -- If we fall through, then the literal does not match any of the |
| -- entries of the enumeration type. This isn't just a constraint |
| -- error situation, it is an illegality (see RM 4.2). |
| |
| Error_Msg_NE |
| ("character not defined for }", N, First_Subtype (B_Typ)); |
| end Resolve_Character_Literal; |
| |
| --------------------------- |
| -- Resolve_Comparison_Op -- |
| --------------------------- |
| |
| -- Context requires a boolean type, and plays no role in resolution. |
| -- Processing identical to that for equality operators. The result |
| -- type is the base type, which matters when pathological subtypes of |
| -- booleans with limited ranges are used. |
| |
| procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id; |
| |
| begin |
| Check_Direct_Boolean_Op (N); |
| |
| -- If this is an intrinsic operation which is not predefined, use |
| -- the types of its declared arguments to resolve the possibly |
| -- overloaded operands. Otherwise the operands are unambiguous and |
| -- specify the expected type. |
| |
| if Scope (Entity (N)) /= Standard_Standard then |
| T := Etype (First_Entity (Entity (N))); |
| else |
| T := Find_Unique_Type (L, R); |
| |
| if T = Any_Fixed then |
| T := Unique_Fixed_Point_Type (L); |
| end if; |
| end if; |
| |
| Set_Etype (N, Base_Type (Typ)); |
| Generate_Reference (T, N, ' '); |
| |
| if T /= Any_Type then |
| if T = Any_String |
| or else T = Any_Composite |
| or else T = Any_Character |
| then |
| if T = Any_Character then |
| Ambiguous_Character (L); |
| else |
| Error_Msg_N ("ambiguous operands for comparison", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| |
| else |
| if Comes_From_Source (N) |
| and then Has_Unchecked_Union (T) |
| then |
| Error_Msg_N |
| ("cannot compare Unchecked_Union values", N); |
| end if; |
| |
| Resolve (L, T); |
| Resolve (R, T); |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, T); |
| Eval_Relational_Op (N); |
| end if; |
| end if; |
| end Resolve_Comparison_Op; |
| |
| ------------------------------------ |
| -- Resolve_Conditional_Expression -- |
| ------------------------------------ |
| |
| procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is |
| Condition : constant Node_Id := First (Expressions (N)); |
| Then_Expr : constant Node_Id := Next (Condition); |
| Else_Expr : constant Node_Id := Next (Then_Expr); |
| |
| begin |
| Resolve (Condition, Standard_Boolean); |
| Resolve (Then_Expr, Typ); |
| Resolve (Else_Expr, Typ); |
| |
| Set_Etype (N, Typ); |
| Eval_Conditional_Expression (N); |
| end Resolve_Conditional_Expression; |
| |
| ----------------------------------------- |
| -- Resolve_Discrete_Subtype_Indication -- |
| ----------------------------------------- |
| |
| procedure Resolve_Discrete_Subtype_Indication |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| R : Node_Id; |
| S : Entity_Id; |
| |
| begin |
| Analyze (Subtype_Mark (N)); |
| S := Entity (Subtype_Mark (N)); |
| |
| if Nkind (Constraint (N)) /= N_Range_Constraint then |
| Error_Msg_N ("expect range constraint for discrete type", N); |
| Set_Etype (N, Any_Type); |
| |
| else |
| R := Range_Expression (Constraint (N)); |
| |
| if R = Error then |
| return; |
| end if; |
| |
| Analyze (R); |
| |
| if Base_Type (S) /= Base_Type (Typ) then |
| Error_Msg_NE |
| ("expect subtype of }", N, First_Subtype (Typ)); |
| |
| -- Rewrite the constraint as a range of Typ |
| -- to allow compilation to proceed further. |
| |
| Set_Etype (N, Typ); |
| Rewrite (Low_Bound (R), |
| Make_Attribute_Reference (Sloc (Low_Bound (R)), |
| Prefix => New_Occurrence_Of (Typ, Sloc (R)), |
| Attribute_Name => Name_First)); |
| Rewrite (High_Bound (R), |
| Make_Attribute_Reference (Sloc (High_Bound (R)), |
| Prefix => New_Occurrence_Of (Typ, Sloc (R)), |
| Attribute_Name => Name_First)); |
| |
| else |
| Resolve (R, Typ); |
| Set_Etype (N, Etype (R)); |
| |
| -- Additionally, we must check that the bounds are compatible |
| -- with the given subtype, which might be different from the |
| -- type of the context. |
| |
| Apply_Range_Check (R, S); |
| |
| -- ??? If the above check statically detects a Constraint_Error |
| -- it replaces the offending bound(s) of the range R with a |
| -- Constraint_Error node. When the itype which uses these bounds |
| -- is frozen the resulting call to Duplicate_Subexpr generates |
| -- a new temporary for the bounds. |
| |
| -- Unfortunately there are other itypes that are also made depend |
| -- on these bounds, so when Duplicate_Subexpr is called they get |
| -- a forward reference to the newly created temporaries and Gigi |
| -- aborts on such forward references. This is probably sign of a |
| -- more fundamental problem somewhere else in either the order of |
| -- itype freezing or the way certain itypes are constructed. |
| |
| -- To get around this problem we call Remove_Side_Effects right |
| -- away if either bounds of R are a Constraint_Error. |
| |
| declare |
| L : constant Node_Id := Low_Bound (R); |
| H : constant Node_Id := High_Bound (R); |
| |
| begin |
| if Nkind (L) = N_Raise_Constraint_Error then |
| Remove_Side_Effects (L); |
| end if; |
| |
| if Nkind (H) = N_Raise_Constraint_Error then |
| Remove_Side_Effects (H); |
| end if; |
| end; |
| |
| Check_Unset_Reference (Low_Bound (R)); |
| Check_Unset_Reference (High_Bound (R)); |
| end if; |
| end if; |
| end Resolve_Discrete_Subtype_Indication; |
| |
| ------------------------- |
| -- Resolve_Entity_Name -- |
| ------------------------- |
| |
| -- Used to resolve identifiers and expanded names |
| |
| procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is |
| E : constant Entity_Id := Entity (N); |
| |
| begin |
| -- If garbage from errors, set to Any_Type and return |
| |
| if No (E) and then Total_Errors_Detected /= 0 then |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- Replace named numbers by corresponding literals. Note that this is |
| -- the one case where Resolve_Entity_Name must reset the Etype, since |
| -- it is currently marked as universal. |
| |
| if Ekind (E) = E_Named_Integer then |
| Set_Etype (N, Typ); |
| Eval_Named_Integer (N); |
| |
| elsif Ekind (E) = E_Named_Real then |
| Set_Etype (N, Typ); |
| Eval_Named_Real (N); |
| |
| -- Allow use of subtype only if it is a concurrent type where we are |
| -- currently inside the body. This will eventually be expanded |
| -- into a call to Self (for tasks) or _object (for protected |
| -- objects). Any other use of a subtype is invalid. |
| |
| elsif Is_Type (E) then |
| if Is_Concurrent_Type (E) |
| and then In_Open_Scopes (E) |
| then |
| null; |
| else |
| Error_Msg_N |
| ("Invalid use of subtype mark in expression or call", N); |
| end if; |
| |
| -- Check discriminant use if entity is discriminant in current scope, |
| -- i.e. discriminant of record or concurrent type currently being |
| -- analyzed. Uses in corresponding body are unrestricted. |
| |
| elsif Ekind (E) = E_Discriminant |
| and then Scope (E) = Current_Scope |
| and then not Has_Completion (Current_Scope) |
| then |
| Check_Discriminant_Use (N); |
| |
| -- A parameterless generic function cannot appear in a context that |
| -- requires resolution. |
| |
| elsif Ekind (E) = E_Generic_Function then |
| Error_Msg_N ("illegal use of generic function", N); |
| |
| elsif Ekind (E) = E_Out_Parameter |
| and then Ada_83 |
| and then (Nkind (Parent (N)) in N_Op |
| or else (Nkind (Parent (N)) = N_Assignment_Statement |
| and then N = Expression (Parent (N))) |
| or else Nkind (Parent (N)) = N_Explicit_Dereference) |
| then |
| Error_Msg_N ("(Ada 83) illegal reading of out parameter", N); |
| |
| -- In all other cases, just do the possible static evaluation |
| |
| else |
| -- A deferred constant that appears in an expression must have |
| -- a completion, unless it has been removed by in-place expansion |
| -- of an aggregate. |
| |
| if Ekind (E) = E_Constant |
| and then Comes_From_Source (E) |
| and then No (Constant_Value (E)) |
| and then Is_Frozen (Etype (E)) |
| and then not In_Default_Expression |
| and then not Is_Imported (E) |
| then |
| |
| if No_Initialization (Parent (E)) |
| or else (Present (Full_View (E)) |
| and then No_Initialization (Parent (Full_View (E)))) |
| then |
| null; |
| else |
| Error_Msg_N ( |
| "deferred constant is frozen before completion", N); |
| end if; |
| end if; |
| |
| Eval_Entity_Name (N); |
| end if; |
| end Resolve_Entity_Name; |
| |
| ------------------- |
| -- Resolve_Entry -- |
| ------------------- |
| |
| procedure Resolve_Entry (Entry_Name : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (Entry_Name); |
| Nam : Entity_Id; |
| New_N : Node_Id; |
| S : Entity_Id; |
| Tsk : Entity_Id; |
| E_Name : Node_Id; |
| Index : Node_Id; |
| |
| function Actual_Index_Type (E : Entity_Id) return Entity_Id; |
| -- If the bounds of the entry family being called depend on task |
| -- discriminants, build a new index subtype where a discriminant is |
| -- replaced with the value of the discriminant of the target task. |
| -- The target task is the prefix of the entry name in the call. |
| |
| ----------------------- |
| -- Actual_Index_Type -- |
| ----------------------- |
| |
| function Actual_Index_Type (E : Entity_Id) return Entity_Id is |
| Typ : constant Entity_Id := Entry_Index_Type (E); |
| Tsk : constant Entity_Id := Scope (E); |
| Lo : constant Node_Id := Type_Low_Bound (Typ); |
| Hi : constant Node_Id := Type_High_Bound (Typ); |
| New_T : Entity_Id; |
| |
| function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id; |
| -- If the bound is given by a discriminant, replace with a reference |
| -- to the discriminant of the same name in the target task. |
| -- If the entry name is the target of a requeue statement and the |
| -- entry is in the current protected object, the bound to be used |
| -- is the discriminal of the object (see apply_range_checks for |
| -- details of the transformation). |
| |
| ----------------------------- |
| -- Actual_Discriminant_Ref -- |
| ----------------------------- |
| |
| function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is |
| Typ : constant Entity_Id := Etype (Bound); |
| Ref : Node_Id; |
| |
| begin |
| Remove_Side_Effects (Bound); |
| |
| if not Is_Entity_Name (Bound) |
| or else Ekind (Entity (Bound)) /= E_Discriminant |
| then |
| return Bound; |
| |
| elsif Is_Protected_Type (Tsk) |
| and then In_Open_Scopes (Tsk) |
| and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement |
| then |
| return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc); |
| |
| else |
| Ref := |
| Make_Selected_Component (Loc, |
| Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))), |
| Selector_Name => New_Occurrence_Of (Entity (Bound), Loc)); |
| Analyze (Ref); |
| Resolve (Ref, Typ); |
| return Ref; |
| end if; |
| end Actual_Discriminant_Ref; |
| |
| -- Start of processing for Actual_Index_Type |
| |
| begin |
| if not Has_Discriminants (Tsk) |
| or else (not Is_Entity_Name (Lo) |
| and then not Is_Entity_Name (Hi)) |
| then |
| return Entry_Index_Type (E); |
| |
| else |
| New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name)); |
| Set_Etype (New_T, Base_Type (Typ)); |
| Set_Size_Info (New_T, Typ); |
| Set_RM_Size (New_T, RM_Size (Typ)); |
| Set_Scalar_Range (New_T, |
| Make_Range (Sloc (Entry_Name), |
| Low_Bound => Actual_Discriminant_Ref (Lo), |
| High_Bound => Actual_Discriminant_Ref (Hi))); |
| |
| return New_T; |
| end if; |
| end Actual_Index_Type; |
| |
| -- Start of processing of Resolve_Entry |
| |
| begin |
| -- Find name of entry being called, and resolve prefix of name |
| -- with its own type. The prefix can be overloaded, and the name |
| -- and signature of the entry must be taken into account. |
| |
| if Nkind (Entry_Name) = N_Indexed_Component then |
| |
| -- Case of dealing with entry family within the current tasks |
| |
| E_Name := Prefix (Entry_Name); |
| |
| else |
| E_Name := Entry_Name; |
| end if; |
| |
| if Is_Entity_Name (E_Name) then |
| -- Entry call to an entry (or entry family) in the current task. |
| -- This is legal even though the task will deadlock. Rewrite as |
| -- call to current task. |
| |
| -- This can also be a call to an entry in an enclosing task. |
| -- If this is a single task, we have to retrieve its name, |
| -- because the scope of the entry is the task type, not the |
| -- object. If the enclosing task is a task type, the identity |
| -- of the task is given by its own self variable. |
| |
| -- Finally this can be a requeue on an entry of the same task |
| -- or protected object. |
| |
| S := Scope (Entity (E_Name)); |
| |
| for J in reverse 0 .. Scope_Stack.Last loop |
| |
| if Is_Task_Type (Scope_Stack.Table (J).Entity) |
| and then not Comes_From_Source (S) |
| then |
| -- S is an enclosing task or protected object. The concurrent |
| -- declaration has been converted into a type declaration, and |
| -- the object itself has an object declaration that follows |
| -- the type in the same declarative part. |
| |
| Tsk := Next_Entity (S); |
| |
| while Etype (Tsk) /= S loop |
| Next_Entity (Tsk); |
| end loop; |
| |
| S := Tsk; |
| exit; |
| |
| elsif S = Scope_Stack.Table (J).Entity then |
| |
| -- Call to current task. Will be transformed into call to Self |
| |
| exit; |
| |
| end if; |
| end loop; |
| |
| New_N := |
| Make_Selected_Component (Loc, |
| Prefix => New_Occurrence_Of (S, Loc), |
| Selector_Name => |
| New_Occurrence_Of (Entity (E_Name), Loc)); |
| Rewrite (E_Name, New_N); |
| Analyze (E_Name); |
| |
| elsif Nkind (Entry_Name) = N_Selected_Component |
| and then Is_Overloaded (Prefix (Entry_Name)) |
| then |
| -- Use the entry name (which must be unique at this point) to |
| -- find the prefix that returns the corresponding task type or |
| -- protected type. |
| |
| declare |
| Pref : constant Node_Id := Prefix (Entry_Name); |
| Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name)); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (Pref, I, It); |
| |
| while Present (It.Typ) loop |
| |
| if Scope (Ent) = It.Typ then |
| Set_Etype (Pref, It.Typ); |
| exit; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| end if; |
| |
| if Nkind (Entry_Name) = N_Selected_Component then |
| Resolve (Prefix (Entry_Name)); |
| |
| else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component); |
| Nam := Entity (Selector_Name (Prefix (Entry_Name))); |
| Resolve (Prefix (Prefix (Entry_Name))); |
| Index := First (Expressions (Entry_Name)); |
| Resolve (Index, Entry_Index_Type (Nam)); |
| |
| -- Up to this point the expression could have been the actual |
| -- in a simple entry call, and be given by a named association. |
| |
| if Nkind (Index) = N_Parameter_Association then |
| Error_Msg_N ("expect expression for entry index", Index); |
| else |
| Apply_Range_Check (Index, Actual_Index_Type (Nam)); |
| end if; |
| end if; |
| end Resolve_Entry; |
| |
| ------------------------ |
| -- Resolve_Entry_Call -- |
| ------------------------ |
| |
| procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is |
| Entry_Name : constant Node_Id := Name (N); |
| Loc : constant Source_Ptr := Sloc (Entry_Name); |
| Actuals : List_Id; |
| First_Named : Node_Id; |
| Nam : Entity_Id; |
| Norm_OK : Boolean; |
| Obj : Node_Id; |
| Was_Over : Boolean; |
| |
| begin |
| -- We kill all checks here, because it does not seem worth the |
| -- effort to do anything better, an entry call is a big operation. |
| |
| Kill_All_Checks; |
| |
| -- Processing of the name is similar for entry calls and protected |
| -- operation calls. Once the entity is determined, we can complete |
| -- the resolution of the actuals. |
| |
| -- The selector may be overloaded, in the case of a protected object |
| -- with overloaded functions. The type of the context is used for |
| -- resolution. |
| |
| if Nkind (Entry_Name) = N_Selected_Component |
| and then Is_Overloaded (Selector_Name (Entry_Name)) |
| and then Typ /= Standard_Void_Type |
| then |
| declare |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (Selector_Name (Entry_Name), I, It); |
| |
| while Present (It.Typ) loop |
| |
| if Covers (Typ, It.Typ) then |
| Set_Entity (Selector_Name (Entry_Name), It.Nam); |
| Set_Etype (Entry_Name, It.Typ); |
| |
| Generate_Reference (It.Typ, N, ' '); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| end if; |
| |
| Resolve_Entry (Entry_Name); |
| |
| if Nkind (Entry_Name) = N_Selected_Component then |
| |
| -- Simple entry call. |
| |
| Nam := Entity (Selector_Name (Entry_Name)); |
| Obj := Prefix (Entry_Name); |
| Was_Over := Is_Overloaded (Selector_Name (Entry_Name)); |
| |
| else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component); |
| |
| -- Call to member of entry family. |
| |
| Nam := Entity (Selector_Name (Prefix (Entry_Name))); |
| Obj := Prefix (Prefix (Entry_Name)); |
| Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name))); |
| end if; |
| |
| -- We cannot in general check the maximum depth of protected entry |
| -- calls at compile time. But we can tell that any protected entry |
| -- call at all violates a specified nesting depth of zero. |
| |
| if Is_Protected_Type (Scope (Nam)) then |
| Check_Restriction (Max_Entry_Queue_Depth, N); |
| end if; |
| |
| -- Use context type to disambiguate a protected function that can be |
| -- called without actuals and that returns an array type, and where |
| -- the argument list may be an indexing of the returned value. |
| |
| if Ekind (Nam) = E_Function |
| and then Needs_No_Actuals (Nam) |
| and then Present (Parameter_Associations (N)) |
| and then |
| ((Is_Array_Type (Etype (Nam)) |
| and then Covers (Typ, Component_Type (Etype (Nam)))) |
| |
| or else (Is_Access_Type (Etype (Nam)) |
| and then Is_Array_Type (Designated_Type (Etype (Nam))) |
| and then Covers (Typ, |
| Component_Type (Designated_Type (Etype (Nam)))))) |
| then |
| declare |
| Index_Node : Node_Id; |
| |
| begin |
| Index_Node := |
| Make_Indexed_Component (Loc, |
| Prefix => |
| Make_Function_Call (Loc, |
| Name => Relocate_Node (Entry_Name)), |
| Expressions => Parameter_Associations (N)); |
| |
| -- Since we are correcting a node classification error made by |
| -- the parser, we call Replace rather than Rewrite. |
| |
| Replace (N, Index_Node); |
| Set_Etype (Prefix (N), Etype (Nam)); |
| Set_Etype (N, Typ); |
| Resolve_Indexed_Component (N, Typ); |
| return; |
| end; |
| end if; |
| |
| -- The operation name may have been overloaded. Order the actuals |
| -- according to the formals of the resolved entity, and set the |
| -- return type to that of the operation. |
| |
| if Was_Over then |
| Normalize_Actuals (N, Nam, False, Norm_OK); |
| pragma Assert (Norm_OK); |
| Set_Etype (N, Etype (Nam)); |
| end if; |
| |
| Resolve_Actuals (N, Nam); |
| Generate_Reference (Nam, Entry_Name); |
| |
| if Ekind (Nam) = E_Entry |
| or else Ekind (Nam) = E_Entry_Family |
| then |
| Check_Potentially_Blocking_Operation (N); |
| end if; |
| |
| -- Verify that a procedure call cannot masquerade as an entry |
| -- call where an entry call is expected. |
| |
| if Ekind (Nam) = E_Procedure then |
| if Nkind (Parent (N)) = N_Entry_Call_Alternative |
| and then N = Entry_Call_Statement (Parent (N)) |
| then |
| Error_Msg_N ("entry call required in select statement", N); |
| |
| elsif Nkind (Parent (N)) = N_Triggering_Alternative |
| and then N = Triggering_Statement (Parent (N)) |
| then |
| Error_Msg_N ("triggering statement cannot be procedure call", N); |
| |
| elsif Ekind (Scope (Nam)) = E_Task_Type |
| and then not In_Open_Scopes (Scope (Nam)) |
| then |
| Error_Msg_N ("Task has no entry with this name", Entry_Name); |
| end if; |
| end if; |
| |
| -- After resolution, entry calls and protected procedure calls |
| -- are changed into entry calls, for expansion. The structure |
| -- of the node does not change, so it can safely be done in place. |
| -- Protected function calls must keep their structure because they |
| -- are subexpressions. |
| |
| if Ekind (Nam) /= E_Function then |
| |
| -- A protected operation that is not a function may modify the |
| -- corresponding object, and cannot apply to a constant. |
| -- If this is an internal call, the prefix is the type itself. |
| |
| if Is_Protected_Type (Scope (Nam)) |
| and then not Is_Variable (Obj) |
| and then (not Is_Entity_Name (Obj) |
| or else not Is_Type (Entity (Obj))) |
| then |
| Error_Msg_N |
| ("prefix of protected procedure or entry call must be variable", |
| Entry_Name); |
| end if; |
| |
| Actuals := Parameter_Associations (N); |
| First_Named := First_Named_Actual (N); |
| |
| Rewrite (N, |
| Make_Entry_Call_Statement (Loc, |
| Name => Entry_Name, |
| Parameter_Associations => Actuals)); |
| |
| Set_First_Named_Actual (N, First_Named); |
| Set_Analyzed (N, True); |
| |
| -- Protected functions can return on the secondary stack, in which |
| -- case we must trigger the transient scope mechanism |
| |
| elsif Expander_Active |
| and then Requires_Transient_Scope (Etype (Nam)) |
| then |
| Establish_Transient_Scope (N, |
| Sec_Stack => not Functions_Return_By_DSP_On_Target); |
| end if; |
| end Resolve_Entry_Call; |
| |
| ------------------------- |
| -- Resolve_Equality_Op -- |
| ------------------------- |
| |
| -- Both arguments must have the same type, and the boolean context |
| -- does not participate in the resolution. The first pass verifies |
| -- that the interpretation is not ambiguous, and the type of the left |
| -- argument is correctly set, or is Any_Type in case of ambiguity. |
| -- If both arguments are strings or aggregates, allocators, or Null, |
| -- they are ambiguous even though they carry a single (universal) type. |
| -- Diagnose this case here. |
| |
| procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id := Find_Unique_Type (L, R); |
| |
| function Find_Unique_Access_Type return Entity_Id; |
| -- In the case of allocators, make a last-ditch attempt to find a single |
| -- access type with the right designated type. This is semantically |
| -- dubious, and of no interest to any real code, but c48008a makes it |
| -- all worthwhile. |
| |
| ----------------------------- |
| -- Find_Unique_Access_Type -- |
| ----------------------------- |
| |
| function Find_Unique_Access_Type return Entity_Id is |
| Acc : Entity_Id; |
| E : Entity_Id; |
| S : Entity_Id := Current_Scope; |
| |
| begin |
| if Ekind (Etype (R)) = E_Allocator_Type then |
| Acc := Designated_Type (Etype (R)); |
| |
| elsif Ekind (Etype (L)) = E_Allocator_Type then |
| Acc := Designated_Type (Etype (L)); |
| |
| else |
| return Empty; |
| end if; |
| |
| while S /= Standard_Standard loop |
| E := First_Entity (S); |
| |
| while Present (E) loop |
| |
| if Is_Type (E) |
| and then Is_Access_Type (E) |
| and then Ekind (E) /= E_Allocator_Type |
| and then Designated_Type (E) = Base_Type (Acc) |
| then |
| return E; |
| end if; |
| |
| Next_Entity (E); |
| end loop; |
| |
| S := Scope (S); |
| end loop; |
| |
| return Empty; |
| end Find_Unique_Access_Type; |
| |
| -- Start of processing for Resolve_Equality_Op |
| |
| begin |
| Check_Direct_Boolean_Op (N); |
| |
| Set_Etype (N, Base_Type (Typ)); |
| Generate_Reference (T, N, ' '); |
| |
| if T = Any_Fixed then |
| T := Unique_Fixed_Point_Type (L); |
| end if; |
| |
| if T /= Any_Type then |
| |
| if T = Any_String |
| or else T = Any_Composite |
| or else T = Any_Character |
| then |
| |
| if T = Any_Character then |
| Ambiguous_Character (L); |
| else |
| Error_Msg_N ("ambiguous operands for equality", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif T = Any_Access |
| or else Ekind (T) = E_Allocator_Type |
| then |
| T := Find_Unique_Access_Type; |
| |
| if No (T) then |
| Error_Msg_N ("ambiguous operands for equality", N); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| end if; |
| |
| if Comes_From_Source (N) |
| and then Has_Unchecked_Union (T) |
| then |
| Error_Msg_N |
| ("cannot compare Unchecked_Union values", N); |
| end if; |
| |
| Resolve (L, T); |
| Resolve (R, T); |
| |
| if Warn_On_Redundant_Constructs |
| and then Comes_From_Source (N) |
| and then Is_Entity_Name (R) |
| and then Entity (R) = Standard_True |
| and then Comes_From_Source (R) |
| then |
| Error_Msg_N ("comparison with True is redundant?", R); |
| end if; |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, T); |
| |
| -- If this is an inequality, it may be the implicit inequality |
| -- created for a user-defined operation, in which case the corres- |
| -- ponding equality operation is not intrinsic, and the operation |
| -- cannot be constant-folded. Else fold. |
| |
| if Nkind (N) = N_Op_Eq |
| or else Comes_From_Source (Entity (N)) |
| or else Ekind (Entity (N)) = E_Operator |
| or else Is_Intrinsic_Subprogram |
| (Corresponding_Equality (Entity (N))) |
| then |
| Eval_Relational_Op (N); |
| elsif Nkind (N) = N_Op_Ne |
| and then Is_Abstract (Entity (N)) |
| then |
| Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N)); |
| end if; |
| end if; |
| end Resolve_Equality_Op; |
| |
| ---------------------------------- |
| -- Resolve_Explicit_Dereference -- |
| ---------------------------------- |
| |
| procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is |
| P : constant Node_Id := Prefix (N); |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| -- Now that we know the type, check that this is not a |
| -- dereference of an uncompleted type. Note that this |
| -- is not entirely correct, because dereferences of |
| -- private types are legal in default expressions. |
| -- This consideration also applies to similar checks |
| -- for allocators, qualified expressions, and type |
| -- conversions. ??? |
| |
| Check_Fully_Declared (Typ, N); |
| |
| if Is_Overloaded (P) then |
| |
| -- Use the context type to select the prefix that has the |
| -- correct designated type. |
| |
| Get_First_Interp (P, I, It); |
| while Present (It.Typ) loop |
| exit when Is_Access_Type (It.Typ) |
| and then Covers (Typ, Designated_Type (It.Typ)); |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| Resolve (P, It.Typ); |
| Set_Etype (N, Designated_Type (It.Typ)); |
| |
| else |
| Resolve (P); |
| end if; |
| |
| if Is_Access_Type (Etype (P)) then |
| Apply_Access_Check (N); |
| end if; |
| |
| -- If the designated type is a packed unconstrained array type, |
| -- and the explicit dereference is not in the context of an |
| -- attribute reference, then we must compute and set the actual |
| -- subtype, since it is needed by Gigi. The reason we exclude |
| -- the attribute case is that this is handled fine by Gigi, and |
| -- in fact we use such attributes to build the actual subtype. |
| -- We also exclude generated code (which builds actual subtypes |
| -- directly if they are needed). |
| |
| if Is_Array_Type (Etype (N)) |
| and then Is_Packed (Etype (N)) |
| and then not Is_Constrained (Etype (N)) |
| and then Nkind (Parent (N)) /= N_Attribute_Reference |
| and then Comes_From_Source (N) |
| then |
| Set_Etype (N, Get_Actual_Subtype (N)); |
| end if; |
| |
| -- Note: there is no Eval processing required for an explicit |
| -- deference, because the type is known to be an allocators, and |
| -- allocator expressions can never be static. |
| |
| end Resolve_Explicit_Dereference; |
| |
| ------------------------------- |
| -- Resolve_Indexed_Component -- |
| ------------------------------- |
| |
| procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is |
| Name : constant Node_Id := Prefix (N); |
| Expr : Node_Id; |
| Array_Type : Entity_Id := Empty; -- to prevent junk warning |
| Index : Node_Id; |
| |
| begin |
| if Is_Overloaded (Name) then |
| |
| -- Use the context type to select the prefix that yields the |
| -- correct component type. |
| |
| declare |
| I : Interp_Index; |
| It : Interp; |
| I1 : Interp_Index := 0; |
| P : constant Node_Id := Prefix (N); |
| Found : Boolean := False; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| |
| while Present (It.Typ) loop |
| |
| if (Is_Array_Type (It.Typ) |
| and then Covers (Typ, Component_Type (It.Typ))) |
| or else (Is_Access_Type (It.Typ) |
| and then Is_Array_Type (Designated_Type (It.Typ)) |
| and then Covers |
| (Typ, Component_Type (Designated_Type (It.Typ)))) |
| then |
| if Found then |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N ("ambiguous prefix for indexing", N); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| |
| else |
| Array_Type := Etype (Name); |
| end if; |
| |
| Resolve (Name, Array_Type); |
| Array_Type := Get_Actual_Subtype_If_Available (Name); |
| |
| -- If prefix is access type, dereference to get real array type. |
| -- Note: we do not apply an access check because the expander always |
| -- introduces an explicit dereference, and the check will happen there. |
| |
| if Is_Access_Type (Array_Type) then |
| Array_Type := Designated_Type (Array_Type); |
| end if; |
| |
| -- If name was overloaded, set component type correctly now. |
| |
| Set_Etype (N, Component_Type (Array_Type)); |
| |
| Index := First_Index (Array_Type); |
| Expr := First (Expressions (N)); |
| |
| -- The prefix may have resolved to a string literal, in which case |
| -- its etype has a special representation. This is only possible |
| -- currently if the prefix is a static concatenation, written in |
| -- functional notation. |
| |
| if Ekind (Array_Type) = E_String_Literal_Subtype then |
| Resolve (Expr, Standard_Positive); |
| |
| else |
| while Present (Index) and Present (Expr) loop |
| Resolve (Expr, Etype (Index)); |
| Check_Unset_Reference (Expr); |
| |
| if Is_Scalar_Type (Etype (Expr)) then |
| Apply_Scalar_Range_Check (Expr, Etype (Index)); |
| else |
| Apply_Range_Check (Expr, Get_Actual_Subtype (Index)); |
| end if; |
| |
| Next_Index (Index); |
| Next (Expr); |
| end loop; |
| end if; |
| |
| Eval_Indexed_Component (N); |
| end Resolve_Indexed_Component; |
| |
| ----------------------------- |
| -- Resolve_Integer_Literal -- |
| ----------------------------- |
| |
| procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Set_Etype (N, Typ); |
| Eval_Integer_Literal (N); |
| end Resolve_Integer_Literal; |
| |
| --------------------------------- |
| -- Resolve_Intrinsic_Operator -- |
| --------------------------------- |
| |
| procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is |
| Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ)); |
| Op : Entity_Id; |
| Arg1 : Node_Id; |
| Arg2 : Node_Id; |
| |
| begin |
| Op := Entity (N); |
| |
| while Scope (Op) /= Standard_Standard loop |
| Op := Homonym (Op); |
| pragma Assert (Present (Op)); |
| end loop; |
| |
| Set_Entity (N, Op); |
| |
| -- If the operand type is private, rewrite with suitable |
| -- conversions on the operands and the result, to expose |
| -- the proper underlying numeric type. |
| |
| if Is_Private_Type (Typ) then |
| Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N)); |
| |
| if Nkind (N) = N_Op_Expon then |
| Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N)); |
| else |
| Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N)); |
| end if; |
| |
| Save_Interps (Left_Opnd (N), Expression (Arg1)); |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| |
| Set_Left_Opnd (N, Arg1); |
| Set_Right_Opnd (N, Arg2); |
| |
| Set_Etype (N, Btyp); |
| Rewrite (N, Unchecked_Convert_To (Typ, N)); |
| Resolve (N, Typ); |
| |
| elsif Typ /= Etype (Left_Opnd (N)) |
| or else Typ /= Etype (Right_Opnd (N)) |
| then |
| -- Add explicit conversion where needed, and save interpretations |
| -- if operands are overloaded. |
| |
| Arg1 := Convert_To (Typ, Left_Opnd (N)); |
| Arg2 := Convert_To (Typ, Right_Opnd (N)); |
| |
| if Nkind (Arg1) = N_Type_Conversion then |
| Save_Interps (Left_Opnd (N), Expression (Arg1)); |
| end if; |
| |
| if Nkind (Arg2) = N_Type_Conversion then |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| end if; |
| |
| Rewrite (Left_Opnd (N), Arg1); |
| Rewrite (Right_Opnd (N), Arg2); |
| Analyze (Arg1); |
| Analyze (Arg2); |
| Resolve_Arithmetic_Op (N, Typ); |
| |
| else |
| Resolve_Arithmetic_Op (N, Typ); |
| end if; |
| end Resolve_Intrinsic_Operator; |
| |
| -------------------------------------- |
| -- Resolve_Intrinsic_Unary_Operator -- |
| -------------------------------------- |
| |
| procedure Resolve_Intrinsic_Unary_Operator |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ)); |
| Op : Entity_Id; |
| Arg2 : Node_Id; |
| |
| begin |
| Op := Entity (N); |
| |
| while Scope (Op) /= Standard_Standard loop |
| Op := Homonym (Op); |
| pragma Assert (Present (Op)); |
| end loop; |
| |
| Set_Entity (N, Op); |
| |
| if Is_Private_Type (Typ) then |
| Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N)); |
| Save_Interps (Right_Opnd (N), Expression (Arg2)); |
| |
| Set_Right_Opnd (N, Arg2); |
| |
| Set_Etype (N, Btyp); |
| Rewrite (N, Unchecked_Convert_To (Typ, N)); |
| Resolve (N, Typ); |
| |
| else |
| Resolve_Unary_Op (N, Typ); |
| end if; |
| end Resolve_Intrinsic_Unary_Operator; |
| |
| ------------------------ |
| -- Resolve_Logical_Op -- |
| ------------------------ |
| |
| procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : Entity_Id; |
| |
| begin |
| Check_Direct_Boolean_Op (N); |
| |
| -- Predefined operations on scalar types yield the base type. On |
| -- the other hand, logical operations on arrays yield the type of |
| -- the arguments (and the context). |
| |
| if Is_Array_Type (Typ) then |
| B_Typ := Typ; |
| else |
| B_Typ := Base_Type (Typ); |
| end if; |
| |
| -- The following test is required because the operands of the operation |
| -- may be literals, in which case the resulting type appears to be |
| -- compatible with a signed integer type, when in fact it is compatible |
| -- only with modular types. If the context itself is universal, the |
| -- operation is illegal. |
| |
| if not Valid_Boolean_Arg (Typ) then |
| Error_Msg_N ("invalid context for logical operation", N); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif Typ = Any_Modular then |
| Error_Msg_N |
| ("no modular type available in this context", N); |
| Set_Etype (N, Any_Type); |
| return; |
| elsif Is_Modular_Integer_Type (Typ) |
| and then Etype (Left_Opnd (N)) = Universal_Integer |
| and then Etype (Right_Opnd (N)) = Universal_Integer |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| Resolve (Left_Opnd (N), B_Typ); |
| Resolve (Right_Opnd (N), B_Typ); |
| |
| Check_Unset_Reference (Left_Opnd (N)); |
| Check_Unset_Reference (Right_Opnd (N)); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Logical_Op (N); |
| end Resolve_Logical_Op; |
| |
| --------------------------- |
| -- Resolve_Membership_Op -- |
| --------------------------- |
| |
| -- The context can only be a boolean type, and does not determine |
| -- the arguments. Arguments should be unambiguous, but the preference |
| -- rule for universal types applies. |
| |
| procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, Typ); |
| |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| T : Entity_Id; |
| |
| begin |
| if L = Error or else R = Error then |
| return; |
| end if; |
| |
| if not Is_Overloaded (R) |
| and then |
| (Etype (R) = Universal_Integer or else |
| Etype (R) = Universal_Real) |
| and then Is_Overloaded (L) |
| then |
| T := Etype (R); |
| else |
| T := Intersect_Types (L, R); |
| end if; |
| |
| Resolve (L, T); |
| Check_Unset_Reference (L); |
| |
| if Nkind (R) = N_Range |
| and then not Is_Scalar_Type (T) |
| then |
| Error_Msg_N ("scalar type required for range", R); |
| end if; |
| |
| if Is_Entity_Name (R) then |
| Freeze_Expression (R); |
| else |
| Resolve (R, T); |
| Check_Unset_Reference (R); |
| end if; |
| |
| Eval_Membership_Op (N); |
| end Resolve_Membership_Op; |
| |
| ------------------ |
| -- Resolve_Null -- |
| ------------------ |
| |
| procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is |
| begin |
| -- For now allow circumvention of the restriction against |
| -- anonymous null access values via a debug switch to allow |
| -- for easier transition. |
| |
| if not Debug_Flag_J |
| and then Ekind (Typ) = E_Anonymous_Access_Type |
| and then Comes_From_Source (N) |
| then |
| -- In the common case of a call which uses an explicitly null |
| -- value for an access parameter, give specialized error msg |
| |
| if Nkind (Parent (N)) = N_Procedure_Call_Statement |
| or else |
| Nkind (Parent (N)) = N_Function_Call |
| then |
| Error_Msg_N |
| ("null is not allowed as argument for an access parameter", N); |
| |
| -- Standard message for all other cases (are there any?) |
| |
| else |
| Error_Msg_N |
| ("null cannot be of an anonymous access type", N); |
| end if; |
| end if; |
| |
| -- In a distributed context, null for a remote access to subprogram |
| -- may need to be replaced with a special record aggregate. In this |
| -- case, return after having done the transformation. |
| |
| if (Ekind (Typ) = E_Record_Type |
| or else Is_Remote_Access_To_Subprogram_Type (Typ)) |
| and then Remote_AST_Null_Value (N, Typ) |
| then |
| return; |
| end if; |
| |
| -- The null literal takes its type from the context. |
| |
| Set_Etype (N, Typ); |
| end Resolve_Null; |
| |
| ----------------------- |
| -- Resolve_Op_Concat -- |
| ----------------------- |
| |
| procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is |
| Btyp : constant Entity_Id := Base_Type (Typ); |
| Op1 : constant Node_Id := Left_Opnd (N); |
| Op2 : constant Node_Id := Right_Opnd (N); |
| |
| procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean); |
| -- Internal procedure to resolve one operand of concatenation operator. |
| -- The operand is either of the array type or of the component type. |
| -- If the operand is an aggregate, and the component type is composite, |
| -- this is ambiguous if component type has aggregates. |
| |
| ------------------------------- |
| -- Resolve_Concatenation_Arg -- |
| ------------------------------- |
| |
| procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean) is |
| begin |
| if In_Instance then |
| if Is_Comp |
| or else (not Is_Overloaded (Arg) |
| and then Etype (Arg) /= Any_Composite |
| and then Covers (Component_Type (Typ), Etype (Arg))) |
| then |
| Resolve (Arg, Component_Type (Typ)); |
| else |
| Resolve (Arg, Btyp); |
| end if; |
| |
| elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then |
| |
| if Nkind (Arg) = N_Aggregate |
| and then Is_Composite_Type (Component_Type (Typ)) |
| then |
| if Is_Private_Type (Component_Type (Typ)) then |
| Resolve (Arg, Btyp); |
| |
| else |
| Error_Msg_N ("ambiguous aggregate must be qualified", Arg); |
| Set_Etype (Arg, Any_Type); |
| end if; |
| |
| else |
| if Is_Overloaded (Arg) |
| and then Has_Compatible_Type (Arg, Typ) |
| and then Etype (Arg) /= Any_Type |
| then |
| Error_Msg_N ("ambiguous operand for concatenation!", Arg); |
| |
| declare |
| I : Interp_Index; |
| It : Interp; |
| |
| begin |
| Get_First_Interp (Arg, I, It); |
| |
| while Present (It.Nam) loop |
| |
| if Base_Type (Etype (It.Nam)) = Base_Type (Typ) |
| or else Base_Type (Etype (It.Nam)) = |
| Base_Type (Component_Type (Typ)) |
| then |
| Error_Msg_Sloc := Sloc (It.Nam); |
| Error_Msg_N ("\possible interpretation#", Arg); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| end if; |
| |
| Resolve (Arg, Component_Type (Typ)); |
| |
| if Nkind (Arg) = N_String_Literal then |
| Set_Etype (Arg, Component_Type (Typ)); |
| end if; |
| |
| if Arg = Left_Opnd (N) then |
| Set_Is_Component_Left_Opnd (N); |
| else |
| Set_Is_Component_Right_Opnd (N); |
| end if; |
| end if; |
| |
| else |
| Resolve (Arg, Btyp); |
| end if; |
| |
| Check_Unset_Reference (Arg); |
| end Resolve_Concatenation_Arg; |
| |
| -- Start of processing for Resolve_Op_Concat |
| |
| begin |
| Set_Etype (N, Btyp); |
| |
| if Is_Limited_Composite (Btyp) then |
| Error_Msg_N ("concatenation not available for limited array", N); |
| Explain_Limited_Type (Btyp, N); |
| end if; |
| |
| -- If the operands are themselves concatenations, resolve them as |
| -- such directly. This removes several layers of recursion and allows |
| -- GNAT to handle larger multiple concatenations. |
| |
| if Nkind (Op1) = N_Op_Concat |
| and then not Is_Array_Type (Component_Type (Typ)) |
| and then Entity (Op1) = Entity (N) |
| then |
| Resolve_Op_Concat (Op1, Typ); |
| else |
| Resolve_Concatenation_Arg |
| (Op1, Is_Component_Left_Opnd (N)); |
| end if; |
| |
| if Nkind (Op2) = N_Op_Concat |
| and then not Is_Array_Type (Component_Type (Typ)) |
| and then Entity (Op2) = Entity (N) |
| then |
| Resolve_Op_Concat (Op2, Typ); |
| else |
| Resolve_Concatenation_Arg |
| (Op2, Is_Component_Right_Opnd (N)); |
| end if; |
| |
| Generate_Operator_Reference (N, Typ); |
| |
| if Is_String_Type (Typ) then |
| Eval_Concatenation (N); |
| end if; |
| |
| -- If this is not a static concatenation, but the result is a |
| -- string type (and not an array of strings) insure that static |
| -- string operands have their subtypes properly constructed. |
| |
| if Nkind (N) /= N_String_Literal |
| and then Is_Character_Type (Component_Type (Typ)) |
| then |
| Set_String_Literal_Subtype (Op1, Typ); |
| Set_String_Literal_Subtype (Op2, Typ); |
| end if; |
| end Resolve_Op_Concat; |
| |
| ---------------------- |
| -- Resolve_Op_Expon -- |
| ---------------------- |
| |
| procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| |
| begin |
| -- Catch attempts to do fixed-point exponentation with universal |
| -- operands, which is a case where the illegality is not caught |
| -- during normal operator analysis. |
| |
| if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then |
| Error_Msg_N ("exponentiation not available for fixed point", N); |
| return; |
| end if; |
| |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Operator (N, Typ); |
| return; |
| end if; |
| |
| if Etype (Left_Opnd (N)) = Universal_Integer |
| or else Etype (Left_Opnd (N)) = Universal_Real |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions always are of the base type, not a subtype of it. |
| |
| Resolve (Left_Opnd (N), B_Typ); |
| Resolve (Right_Opnd (N), Standard_Integer); |
| |
| Check_Unset_Reference (Left_Opnd (N)); |
| Check_Unset_Reference (Right_Opnd (N)); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Op_Expon (N); |
| |
| -- Set overflow checking bit. Much cleverer code needed here eventually |
| -- and perhaps the Resolve routines should be separated for the various |
| -- arithmetic operations, since they will need different processing. ??? |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| end if; |
| end Resolve_Op_Expon; |
| |
| -------------------- |
| -- Resolve_Op_Not -- |
| -------------------- |
| |
| procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : Entity_Id; |
| |
| function Parent_Is_Boolean return Boolean; |
| -- This function determines if the parent node is a boolean operator |
| -- or operation (comparison op, membership test, or short circuit form) |
| -- and the not in question is the left operand of this operation. |
| -- Note that if the not is in parens, then false is returned. |
| |
| function Parent_Is_Boolean return Boolean is |
| begin |
| if Paren_Count (N) /= 0 then |
| return False; |
| |
| else |
| case Nkind (Parent (N)) is |
| when N_Op_And | |
| N_Op_Eq | |
| N_Op_Ge | |
| N_Op_Gt | |
| N_Op_Le | |
| N_Op_Lt | |
| N_Op_Ne | |
| N_Op_Or | |
| N_Op_Xor | |
| N_In | |
| N_Not_In | |
| N_And_Then | |
| N_Or_Else => |
| |
| return Left_Opnd (Parent (N)) = N; |
| |
| when others => |
| return False; |
| end case; |
| end if; |
| end Parent_Is_Boolean; |
| |
| -- Start of processing for Resolve_Op_Not |
| |
| begin |
| -- Predefined operations on scalar types yield the base type. On |
| -- the other hand, logical operations on arrays yield the type of |
| -- the arguments (and the context). |
| |
| if Is_Array_Type (Typ) then |
| B_Typ := Typ; |
| else |
| B_Typ := Base_Type (Typ); |
| end if; |
| |
| if not Valid_Boolean_Arg (Typ) then |
| Error_Msg_N ("invalid operand type for operator&", N); |
| Set_Etype (N, Any_Type); |
| return; |
| |
| elsif Typ = Universal_Integer or else Typ = Any_Modular then |
| if Parent_Is_Boolean then |
| Error_Msg_N |
| ("operand of not must be enclosed in parentheses", |
| Right_Opnd (N)); |
| else |
| Error_Msg_N |
| ("no modular type available in this context", N); |
| end if; |
| |
| Set_Etype (N, Any_Type); |
| return; |
| |
| else |
| if not Is_Boolean_Type (Typ) |
| and then Parent_Is_Boolean |
| then |
| Error_Msg_N ("?not expression should be parenthesized here", N); |
| end if; |
| |
| Resolve (Right_Opnd (N), B_Typ); |
| Check_Unset_Reference (Right_Opnd (N)); |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Op_Not (N); |
| end if; |
| end Resolve_Op_Not; |
| |
| ----------------------------- |
| -- Resolve_Operator_Symbol -- |
| ----------------------------- |
| |
| -- Nothing to be done, all resolved already |
| |
| procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, N); |
| pragma Warnings (Off, Typ); |
| |
| begin |
| null; |
| end Resolve_Operator_Symbol; |
| |
| ---------------------------------- |
| -- Resolve_Qualified_Expression -- |
| ---------------------------------- |
| |
| procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is |
| pragma Warnings (Off, Typ); |
| |
| Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N)); |
| Expr : constant Node_Id := Expression (N); |
| |
| begin |
| Resolve (Expr, Target_Typ); |
| |
| -- A qualified expression requires an exact match of the type, |
| -- class-wide matching is not allowed. |
| |
| if Is_Class_Wide_Type (Target_Typ) |
| and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ) |
| then |
| Wrong_Type (Expr, Target_Typ); |
| end if; |
| |
| -- If the target type is unconstrained, then we reset the type of |
| -- the result from the type of the expression. For other cases, the |
| -- actual subtype of the expression is the target type. |
| |
| if Is_Composite_Type (Target_Typ) |
| and then not Is_Constrained (Target_Typ) |
| then |
| Set_Etype (N, Etype (Expr)); |
| end if; |
| |
| Eval_Qualified_Expression (N); |
| end Resolve_Qualified_Expression; |
| |
| ------------------- |
| -- Resolve_Range -- |
| ------------------- |
| |
| procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is |
| L : constant Node_Id := Low_Bound (N); |
| H : constant Node_Id := High_Bound (N); |
| |
| begin |
| Set_Etype (N, Typ); |
| Resolve (L, Typ); |
| Resolve (H, Typ); |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (H); |
| |
| -- We have to check the bounds for being within the base range as |
| -- required for a non-static context. Normally this is automatic |
| -- and done as part of evaluating expressions, but the N_Range |
| -- node is an exception, since in GNAT we consider this node to |
| -- be a subexpression, even though in Ada it is not. The circuit |
| -- in Sem_Eval could check for this, but that would put the test |
| -- on the main evaluation path for expressions. |
| |
| Check_Non_Static_Context (L); |
| Check_Non_Static_Context (H); |
| |
| -- If bounds are static, constant-fold them, so size computations |
| -- are identical between front-end and back-end. Do not perform this |
| -- transformation while analyzing generic units, as type information |
| -- would then be lost when reanalyzing the constant node in the |
| -- instance. |
| |
| if Is_Discrete_Type (Typ) and then Expander_Active then |
| if Is_OK_Static_Expression (L) then |
| Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L)); |
| end if; |
| |
| if Is_OK_Static_Expression (H) then |
| Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H)); |
| end if; |
| end if; |
| end Resolve_Range; |
| |
| -------------------------- |
| -- Resolve_Real_Literal -- |
| -------------------------- |
| |
| procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is |
| Actual_Typ : constant Entity_Id := Etype (N); |
| |
| begin |
| -- Special processing for fixed-point literals to make sure that the |
| -- value is an exact multiple of small where this is required. We |
| -- skip this for the universal real case, and also for generic types. |
| |
| if Is_Fixed_Point_Type (Typ) |
| and then Typ /= Universal_Fixed |
| and then Typ /= Any_Fixed |
| and then not Is_Generic_Type (Typ) |
| then |
| declare |
| Val : constant Ureal := Realval (N); |
| Cintr : constant Ureal := Val / Small_Value (Typ); |
| Cint : constant Uint := UR_Trunc (Cintr); |
| Den : constant Uint := Norm_Den (Cintr); |
| Stat : Boolean; |
| |
| begin |
| -- Case of literal is not an exact multiple of the Small |
| |
| if Den /= 1 then |
| |
| -- For a source program literal for a decimal fixed-point |
| -- type, this is statically illegal (RM 4.9(36)). |
| |
| if Is_Decimal_Fixed_Point_Type (Typ) |
| and then Actual_Typ = Universal_Real |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_N ("value has extraneous low order digits", N); |
| end if; |
| |
| -- Replace literal by a value that is the exact representation |
| -- of a value of the type, i.e. a multiple of the small value, |
| -- by truncation, since Machine_Rounds is false for all GNAT |
| -- fixed-point types (RM 4.9(38)). |
| |
| Stat := Is_Static_Expression (N); |
| Rewrite (N, |
| Make_Real_Literal (Sloc (N), |
| Realval => Small_Value (Typ) * Cint)); |
| |
| Set_Is_Static_Expression (N, Stat); |
| end if; |
| |
| -- In all cases, set the corresponding integer field |
| |
| Set_Corresponding_Integer_Value (N, Cint); |
| end; |
| end if; |
| |
| -- Now replace the actual type by the expected type as usual |
| |
| Set_Etype (N, Typ); |
| Eval_Real_Literal (N); |
| end Resolve_Real_Literal; |
| |
| ----------------------- |
| -- Resolve_Reference -- |
| ----------------------- |
| |
| procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is |
| P : constant Node_Id := Prefix (N); |
| |
| begin |
| -- Replace general access with specific type |
| |
| if Ekind (Etype (N)) = E_Allocator_Type then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| Resolve (P, Designated_Type (Etype (N))); |
| |
| -- If we are taking the reference of a volatile entity, then treat |
| -- it as a potential modification of this entity. This is much too |
| -- conservative, but is necessary because remove side effects can |
| -- result in transformations of normal assignments into reference |
| -- sequences that otherwise fail to notice the modification. |
| |
| if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then |
| Note_Possible_Modification (P); |
| end if; |
| end Resolve_Reference; |
| |
| -------------------------------- |
| -- Resolve_Selected_Component -- |
| -------------------------------- |
| |
| procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is |
| Comp : Entity_Id; |
| Comp1 : Entity_Id := Empty; -- prevent junk warning |
| P : constant Node_Id := Prefix (N); |
| S : constant Node_Id := Selector_Name (N); |
| T : Entity_Id := Etype (P); |
| I : Interp_Index; |
| I1 : Interp_Index := 0; -- prevent junk warning |
| It : Interp; |
| It1 : Interp; |
| Found : Boolean; |
| |
| function Init_Component return Boolean; |
| -- Check whether this is the initialization of a component within an |
| -- init proc (by assignment or call to another init proc). If true, |
| -- there is no need for a discriminant check. |
| |
| -------------------- |
| -- Init_Component -- |
| -------------------- |
| |
| function Init_Component return Boolean is |
| begin |
| return Inside_Init_Proc |
| and then Nkind (Prefix (N)) = N_Identifier |
| and then Chars (Prefix (N)) = Name_uInit |
| and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative; |
| end Init_Component; |
| |
| -- Start of processing for Resolve_Selected_Component |
| |
| begin |
| if Is_Overloaded (P) then |
| |
| -- Use the context type to select the prefix that has a selector |
| -- of the correct name and type. |
| |
| Found := False; |
| Get_First_Interp (P, I, It); |
| |
| Search : while Present (It.Typ) loop |
| if Is_Access_Type (It.Typ) then |
| T := Designated_Type (It.Typ); |
| else |
| T := It.Typ; |
| end if; |
| |
| if Is_Record_Type (T) then |
| Comp := First_Entity (T); |
| |
| while Present (Comp) loop |
| |
| if Chars (Comp) = Chars (S) |
| and then Covers (Etype (Comp), Typ) |
| then |
| if not Found then |
| Found := True; |
| I1 := I; |
| It1 := It; |
| Comp1 := Comp; |
| |
| else |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N |
| ("ambiguous prefix for selected component", N); |
| Set_Etype (N, Typ); |
| return; |
| |
| else |
| It1 := It; |
| |
| if Scope (Comp1) /= It1.Typ then |
| |
| -- Resolution chooses the new interpretation. |
| -- Find the component with the right name. |
| |
| Comp1 := First_Entity (It1.Typ); |
| |
| while Present (Comp1) |
| and then Chars (Comp1) /= Chars (S) |
| loop |
| Comp1 := Next_Entity (Comp1); |
| end loop; |
| end if; |
| |
| exit Search; |
| end if; |
| end if; |
| end if; |
| |
| Comp := Next_Entity (Comp); |
| end loop; |
| |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop Search; |
| |
| Resolve (P, It1.Typ); |
| Set_Etype (N, Typ); |
| Set_Entity (S, Comp1); |
| |
| else |
| -- Resolve prefix with its type |
| |
| Resolve (P, T); |
| end if; |
| |
| -- Deal with access type case |
| |
| if Is_Access_Type (Etype (P)) then |
| Apply_Access_Check (N); |
| T := Designated_Type (Etype (P)); |
| else |
| T := Etype (P); |
| end if; |
| |
| if Has_Discriminants (T) |
| and then (Ekind (Entity (S)) = E_Component |
| or else |
| Ekind (Entity (S)) = E_Discriminant) |
| and then Present (Original_Record_Component (Entity (S))) |
| and then Ekind (Original_Record_Component (Entity (S))) = E_Component |
| and then Present (Discriminant_Checking_Func |
| (Original_Record_Component (Entity (S)))) |
| and then not Discriminant_Checks_Suppressed (T) |
| and then not Init_Component |
| then |
| Set_Do_Discriminant_Check (N); |
| end if; |
| |
| if Ekind (Entity (S)) = E_Void then |
| Error_Msg_N ("premature use of component", S); |
| end if; |
| |
| -- If the prefix is a record conversion, this may be a renamed |
| -- discriminant whose bounds differ from those of the original |
| -- one, so we must ensure that a range check is performed. |
| |
| if Nkind (P) = N_Type_Conversion |
| and then Ekind (Entity (S)) = E_Discriminant |
| and then Is_Discrete_Type (Typ) |
| then |
| Set_Etype (N, Base_Type (Typ)); |
| end if; |
| |
| -- Note: No Eval processing is required, because the prefix is of a |
| -- record type, or protected type, and neither can possibly be static. |
| |
| end Resolve_Selected_Component; |
| |
| ------------------- |
| -- Resolve_Shift -- |
| ------------------- |
| |
| procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| -- We do the resolution using the base type, because intermediate values |
| -- in expressions always are of the base type, not a subtype of it. |
| |
| Resolve (L, B_Typ); |
| Resolve (R, Standard_Natural); |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| |
| Set_Etype (N, B_Typ); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Shift (N); |
| end Resolve_Shift; |
| |
| --------------------------- |
| -- Resolve_Short_Circuit -- |
| --------------------------- |
| |
| procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| L : constant Node_Id := Left_Opnd (N); |
| R : constant Node_Id := Right_Opnd (N); |
| |
| begin |
| Resolve (L, B_Typ); |
| Resolve (R, B_Typ); |
| |
| Check_Unset_Reference (L); |
| Check_Unset_Reference (R); |
| |
| Set_Etype (N, B_Typ); |
| Eval_Short_Circuit (N); |
| end Resolve_Short_Circuit; |
| |
| ------------------- |
| -- Resolve_Slice -- |
| ------------------- |
| |
| procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is |
| Name : constant Node_Id := Prefix (N); |
| Drange : constant Node_Id := Discrete_Range (N); |
| Array_Type : Entity_Id := Empty; |
| Index : Node_Id; |
| |
| begin |
| if Is_Overloaded (Name) then |
| |
| -- Use the context type to select the prefix that yields the |
| -- correct array type. |
| |
| declare |
| I : Interp_Index; |
| I1 : Interp_Index := 0; |
| It : Interp; |
| P : constant Node_Id := Prefix (N); |
| Found : Boolean := False; |
| |
| begin |
| Get_First_Interp (P, I, It); |
| |
| while Present (It.Typ) loop |
| |
| if (Is_Array_Type (It.Typ) |
| and then Covers (Typ, It.Typ)) |
| or else (Is_Access_Type (It.Typ) |
| and then Is_Array_Type (Designated_Type (It.Typ)) |
| and then Covers (Typ, Designated_Type (It.Typ))) |
| then |
| if Found then |
| It := Disambiguate (P, I1, I, Any_Type); |
| |
| if It = No_Interp then |
| Error_Msg_N ("ambiguous prefix for slicing", N); |
| Set_Etype (N, Typ); |
| return; |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| else |
| Found := True; |
| Array_Type := It.Typ; |
| I1 := I; |
| end if; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| end; |
| |
| else |
| Array_Type := Etype (Name); |
| end if; |
| |
| Resolve (Name, Array_Type); |
| |
| if Is_Access_Type (Array_Type) then |
| Apply_Access_Check (N); |
| Array_Type := Designated_Type (Array_Type); |
| |
| elsif Is_Entity_Name (Name) |
| or else (Nkind (Name) = N_Function_Call |
| and then not Is_Constrained (Etype (Name))) |
| then |
| Array_Type := Get_Actual_Subtype (Name); |
| end if; |
| |
| -- If name was overloaded, set slice type correctly now |
| |
| Set_Etype (N, Array_Type); |
| |
| -- If the range is specified by a subtype mark, no resolution |
| -- is necessary. |
| |
| if not Is_Entity_Name (Drange) then |
| Index := First_Index (Array_Type); |
| Resolve (Drange, Base_Type (Etype (Index))); |
| |
| if Nkind (Drange) = N_Range then |
| Apply_Range_Check (Drange, Etype (Index)); |
| end if; |
| end if; |
| |
| Set_Slice_Subtype (N); |
| Eval_Slice (N); |
| end Resolve_Slice; |
| |
| ---------------------------- |
| -- Resolve_String_Literal -- |
| ---------------------------- |
| |
| procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is |
| C_Typ : constant Entity_Id := Component_Type (Typ); |
| R_Typ : constant Entity_Id := Root_Type (C_Typ); |
| Loc : constant Source_Ptr := Sloc (N); |
| Str : constant String_Id := Strval (N); |
| Strlen : constant Nat := String_Length (Str); |
| Subtype_Id : Entity_Id; |
| Need_Check : Boolean; |
| |
| begin |
| -- For a string appearing in a concatenation, defer creation of the |
| -- string_literal_subtype until the end of the resolution of the |
| -- concatenation, because the literal may be constant-folded away. |
| -- This is a useful optimization for long concatenation expressions. |
| |
| -- If the string is an aggregate built for a single character (which |
| -- happens in a non-static context) or a is null string to which special |
| -- checks may apply, we build the subtype. Wide strings must also get |
| -- a string subtype if they come from a one character aggregate. Strings |
| -- generated by attributes might be static, but it is often hard to |
| -- determine whether the enclosing context is static, so we generate |
| -- subtypes for them as well, thus losing some rarer optimizations ??? |
| -- Same for strings that come from a static conversion. |
| |
| Need_Check := |
| (Strlen = 0 and then Typ /= Standard_String) |
| or else Nkind (Parent (N)) /= N_Op_Concat |
| or else (N /= Left_Opnd (Parent (N)) |
| and then N /= Right_Opnd (Parent (N))) |
| or else (Typ = Standard_Wide_String |
| and then Nkind (Original_Node (N)) /= N_String_Literal); |
| |
| -- If the resolving type is itself a string literal subtype, we |
| -- can just reuse it, since there is no point in creating another. |
| |
| if Ekind (Typ) = E_String_Literal_Subtype then |
| Subtype_Id := Typ; |
| |
| elsif Nkind (Parent (N)) = N_Op_Concat |
| and then not Need_Check |
| and then Nkind (Original_Node (N)) /= N_Character_Literal |
| and then Nkind (Original_Node (N)) /= N_Attribute_Reference |
| and then Nkind (Original_Node (N)) /= N_Qualified_Expression |
| and then Nkind (Original_Node (N)) /= N_Type_Conversion |
| then |
| Subtype_Id := Typ; |
| |
| -- Otherwise we must create a string literal subtype. Note that the |
| -- whole idea of string literal subtypes is simply to avoid the need |
| -- for building a full fledged array subtype for each literal. |
| else |
| Set_String_Literal_Subtype (N, Typ); |
| Subtype_Id := Etype (N); |
| end if; |
| |
| if Nkind (Parent (N)) /= N_Op_Concat |
| or else Need_Check |
| then |
| Set_Etype (N, Subtype_Id); |
| Eval_String_Literal (N); |
| end if; |
| |
| if Is_Limited_Composite (Typ) |
| or else Is_Private_Composite (Typ) |
| then |
| Error_Msg_N ("string literal not available for private array", N); |
| Set_Etype (N, Any_Type); |
| return; |
| end if; |
| |
| -- The validity of a null string has been checked in the |
| -- call to Eval_String_Literal. |
| |
| if Strlen = 0 then |
| return; |
| |
| -- Always accept string literal with component type Any_Character, |
| -- which occurs in error situations and in comparisons of literals, |
| -- both of which should accept all literals. |
| |
| elsif R_Typ = Any_Character then |
| return; |
| |
| -- If the type is bit-packed, then we always tranform the string |
| -- literal into a full fledged aggregate. |
| |
| elsif Is_Bit_Packed_Array (Typ) then |
| null; |
| |
| -- Deal with cases of Wide_String and String |
| |
| else |
| -- For Standard.Wide_String, or any other type whose component |
| -- type is Standard.Wide_Character, we know that all the |
| -- characters in the string must be acceptable, since the parser |
| -- accepted the characters as valid character literals. |
| |
| if R_Typ = Standard_Wide_Character then |
| null; |
| |
| -- For the case of Standard.String, or any other type whose |
| -- component type is Standard.Character, we must make sure that |
| -- there are no wide characters in the string, i.e. that it is |
| -- entirely composed of characters in range of type String. |
| |
| -- If the string literal is the result of a static concatenation, |
| -- the test has already been performed on the components, and need |
| -- not be repeated. |
| |
| elsif R_Typ = Standard_Character |
| and then Nkind (Original_Node (N)) /= N_Op_Concat |
| then |
| for J in 1 .. Strlen loop |
| if not In_Character_Range (Get_String_Char (Str, J)) then |
| |
| -- If we are out of range, post error. This is one of the |
| -- very few places that we place the flag in the middle of |
| -- a token, right under the offending wide character. |
| |
| Error_Msg |
| ("literal out of range of type Character", |
| Source_Ptr (Int (Loc) + J)); |
| return; |
| end if; |
| end loop; |
| |
| -- If the root type is not a standard character, then we will convert |
| -- the string into an aggregate and will let the aggregate code do |
| -- the checking. |
| |
| else |
| null; |
| |
| end if; |
| |
| -- See if the component type of the array corresponding to the |
| -- string has compile time known bounds. If yes we can directly |
| -- check whether the evaluation of the string will raise constraint |
| -- error. Otherwise we need to transform the string literal into |
| -- the corresponding character aggregate and let the aggregate |
| -- code do the checking. |
| |
| if R_Typ = Standard_Wide_Character |
| or else R_Typ = Standard_Character |
| then |
| -- Check for the case of full range, where we are definitely OK |
| |
| if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then |
| return; |
| end if; |
| |
| -- Here the range is not the complete base type range, so check |
| |
| declare |
| Comp_Typ_Lo : constant Node_Id := |
| Type_Low_Bound (Component_Type (Typ)); |
| Comp_Typ_Hi : constant Node_Id := |
| Type_High_Bound (Component_Type (Typ)); |
| |
| Char_Val : Uint; |
| |
| begin |
| if Compile_Time_Known_Value (Comp_Typ_Lo) |
| and then Compile_Time_Known_Value (Comp_Typ_Hi) |
| then |
| for J in 1 .. Strlen loop |
| Char_Val := UI_From_Int (Int (Get_String_Char (Str, J))); |
| |
| if Char_Val < Expr_Value (Comp_Typ_Lo) |
| or else Char_Val > Expr_Value (Comp_Typ_Hi) |
| then |
| Apply_Compile_Time_Constraint_Error |
| (N, "character out of range?", CE_Range_Check_Failed, |
| Loc => Source_Ptr (Int (Loc) + J)); |
| end if; |
| end loop; |
| |
| return; |
| end if; |
| end; |
| end if; |
| end if; |
| |
| -- If we got here we meed to transform the string literal into the |
| -- equivalent qualified positional array aggregate. This is rather |
| -- heavy artillery for this situation, but it is hard work to avoid. |
| |
| declare |
| Lits : constant List_Id := New_List; |
| P : Source_Ptr := Loc + 1; |
| C : Char_Code; |
| |
| begin |
| -- Build the character literals, we give them source locations |
| -- that correspond to the string positions, which is a bit tricky |
| -- given the possible presence of wide character escape sequences. |
| |
| for J in 1 .. Strlen loop |
| C := Get_String_Char (Str, J); |
| Set_Character_Literal_Name (C); |
| |
| Append_To (Lits, |
| Make_Character_Literal (P, Name_Find, C)); |
| |
| if In_Character_Range (C) then |
| P := P + 1; |
| |
| -- Should we have a call to Skip_Wide here ??? |
| -- ??? else |
| -- Skip_Wide (P); |
| |
| end if; |
| end loop; |
| |
| Rewrite (N, |
| Make_Qualified_Expression (Loc, |
| Subtype_Mark => New_Reference_To (Typ, Loc), |
| Expression => |
| Make_Aggregate (Loc, Expressions => Lits))); |
| |
| Analyze_And_Resolve (N, Typ); |
| end; |
| end Resolve_String_Literal; |
| |
| ----------------------------- |
| -- Resolve_Subprogram_Info -- |
| ----------------------------- |
| |
| procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is |
| begin |
| Set_Etype (N, Typ); |
| end Resolve_Subprogram_Info; |
| |
| ----------------------------- |
| -- Resolve_Type_Conversion -- |
| ----------------------------- |
| |
| procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is |
| Target_Type : constant Entity_Id := Etype (N); |
| Conv_OK : constant Boolean := Conversion_OK (N); |
| Operand : Node_Id; |
| Opnd_Type : Entity_Id; |
| Rop : Node_Id; |
| Orig_N : Node_Id; |
| Orig_T : Node_Id; |
| |
| begin |
| Operand := Expression (N); |
| |
| if not Conv_OK |
| and then not Valid_Conversion (N, Target_Type, Operand) |
| then |
| return; |
| end if; |
| |
| if Etype (Operand) = Any_Fixed then |
| |
| -- Mixed-mode operation involving a literal. Context must be a fixed |
| -- type which is applied to the literal subsequently. |
| |
| if Is_Fixed_Point_Type (Typ) then |
| Set_Etype (Operand, Universal_Real); |
| |
| elsif Is_Numeric_Type (Typ) |
| and then (Nkind (Operand) = N_Op_Multiply |
| or else Nkind (Operand) = N_Op_Divide) |
| and then (Etype (Right_Opnd (Operand)) = Universal_Real |
| or else Etype (Left_Opnd (Operand)) = Universal_Real) |
| then |
| if Unique_Fixed_Point_Type (N) = Any_Type then |
| return; -- expression is ambiguous. |
| else |
| Set_Etype (Operand, Standard_Duration); |
| end if; |
| |
| if Etype (Right_Opnd (Operand)) = Universal_Real then |
| Rop := New_Copy_Tree (Right_Opnd (Operand)); |
| else |
| Rop := New_Copy_Tree (Left_Opnd (Operand)); |
| end if; |
| |
| Resolve (Rop, Standard_Long_Long_Float); |
| |
| if Realval (Rop) /= Ureal_0 |
| and then abs (Realval (Rop)) < Delta_Value (Standard_Duration) |
| then |
| Error_Msg_N ("universal real operand can only be interpreted?", |
| Rop); |
| Error_Msg_N ("\as Duration, and will lose precision?", Rop); |
| end if; |
| |
| elsif Is_Numeric_Type (Typ) |
| and then Nkind (Operand) in N_Op |
| and then Unique_Fixed_Point_Type (N) /= Any_Type |
| then |
| Set_Etype (Operand, Standard_Duration); |
| |
| else |
| Error_Msg_N ("invalid context for mixed mode operation", N); |
| Set_Etype (Operand, Any_Type); |
| return; |
| end if; |
| end if; |
| |
| Opnd_Type := Etype (Operand); |
| Resolve (Operand); |
| |
| -- Note: we do the Eval_Type_Conversion call before applying the |
| -- required checks for a subtype conversion. This is important, |
| -- since both are prepared under certain circumstances to change |
| -- the type conversion to a constraint error node, but in the case |
| -- of Eval_Type_Conversion this may reflect an illegality in the |
| -- static case, and we would miss the illegality (getting only a |
| -- warning message), if we applied the type conversion checks first. |
| |
| Eval_Type_Conversion (N); |
| |
| -- If after evaluation, we still have a type conversion, then we |
| -- may need to apply checks required for a subtype conversion. |
| |
| -- Skip these type conversion checks if universal fixed operands |
| -- operands involved, since range checks are handled separately for |
| -- these cases (in the appropriate Expand routines in unit Exp_Fixd). |
| |
| if Nkind (N) = N_Type_Conversion |
| and then not Is_Generic_Type (Root_Type (Target_Type)) |
| and then Target_Type /= Universal_Fixed |
| and then Opnd_Type /= Universal_Fixed |
| then |
| Apply_Type_Conversion_Checks (N); |
| end if; |
| |
| -- Issue warning for conversion of simple object to its own type |
| -- We have to test the original nodes, since they may have been |
| -- rewritten by various optimizations. |
| |
| Orig_N := Original_Node (N); |
| |
| if Warn_On_Redundant_Constructs |
| and then Comes_From_Source (Orig_N) |
| and then Nkind (Orig_N) = N_Type_Conversion |
| then |
| Orig_N := Original_Node (Expression (Orig_N)); |
| Orig_T := Target_Type; |
| |
| -- If the node is part of a larger expression, the Target_Type |
| -- may not be the original type of the node if the context is a |
| -- condition. Recover original type to see if conversion is needed. |
| |
| if Is_Boolean_Type (Orig_T) |
| and then Nkind (Parent (N)) in N_Op |
| then |
| Orig_T := Etype (Parent (N)); |
| end if; |
| |
| if Is_Entity_Name (Orig_N) |
| and then Etype (Entity (Orig_N)) = Orig_T |
| then |
| Error_Msg_NE |
| ("?useless conversion, & has this type", N, Entity (Orig_N)); |
| end if; |
| end if; |
| end Resolve_Type_Conversion; |
| |
| ---------------------- |
| -- Resolve_Unary_Op -- |
| ---------------------- |
| |
| procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is |
| B_Typ : constant Entity_Id := Base_Type (Typ); |
| R : constant Node_Id := Right_Opnd (N); |
| OK : Boolean; |
| Lo : Uint; |
| Hi : Uint; |
| |
| begin |
| -- Generate warning for expressions like abs (x mod 2) |
| |
| if Warn_On_Redundant_Constructs |
| and then Nkind (N) = N_Op_Abs |
| then |
| Determine_Range (Right_Opnd (N), OK, Lo, Hi); |
| |
| if OK and then Hi >= Lo and then Lo >= 0 then |
| Error_Msg_N |
| ("?abs applied to known non-negative value has no effect", N); |
| end if; |
| end if; |
| |
| -- Generate warning for expressions like -5 mod 3 |
| |
| if Paren_Count (N) = 0 |
| and then Nkind (N) = N_Op_Minus |
| and then Nkind (Right_Opnd (N)) = N_Op_Mod |
| and then Comes_From_Source (N) |
| then |
| Error_Msg_N |
| ("?unary minus expression should be parenthesized here", N); |
| end if; |
| |
| if Comes_From_Source (N) |
| and then Ekind (Entity (N)) = E_Function |
| and then Is_Imported (Entity (N)) |
| and then Is_Intrinsic_Subprogram (Entity (N)) |
| then |
| Resolve_Intrinsic_Unary_Operator (N, Typ); |
| return; |
| end if; |
| |
| if Etype (R) = Universal_Integer |
| or else Etype (R) = Universal_Real |
| then |
| Check_For_Visible_Operator (N, B_Typ); |
| end if; |
| |
| Set_Etype (N, B_Typ); |
| Resolve (R, B_Typ); |
| |
| Check_Unset_Reference (R); |
| Generate_Operator_Reference (N, B_Typ); |
| Eval_Unary_Op (N); |
| |
| -- Set overflow checking bit. Much cleverer code needed here eventually |
| -- and perhaps the Resolve routines should be separated for the various |
| -- arithmetic operations, since they will need different processing ??? |
| |
| if Nkind (N) in N_Op then |
| if not Overflow_Checks_Suppressed (Etype (N)) then |
| Enable_Overflow_Check (N); |
| end if; |
| end if; |
| end Resolve_Unary_Op; |
| |
| ---------------------------------- |
| -- Resolve_Unchecked_Expression -- |
| ---------------------------------- |
| |
| procedure Resolve_Unchecked_Expression |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| begin |
| Resolve (Expression (N), Typ, Suppress => All_Checks); |
| Set_Etype (N, Typ); |
| end Resolve_Unchecked_Expression; |
| |
| --------------------------------------- |
| -- Resolve_Unchecked_Type_Conversion -- |
| --------------------------------------- |
| |
| procedure Resolve_Unchecked_Type_Conversion |
| (N : Node_Id; |
| Typ : Entity_Id) |
| is |
| pragma Warnings (Off, Typ); |
| |
| Operand : constant Node_Id := Expression (N); |
| Opnd_Type : constant Entity_Id := Etype (Operand); |
| |
| begin |
| -- Resolve operand using its own type. |
| |
| Resolve (Operand, Opnd_Type); |
| Eval_Unchecked_Conversion (N); |
| |
| end Resolve_Unchecked_Type_Conversion; |
| |
| ------------------------------ |
| -- Rewrite_Operator_As_Call -- |
| ------------------------------ |
| |
| procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Actuals : constant List_Id := New_List; |
| New_N : Node_Id; |
| |
| begin |
| if Nkind (N) in N_Binary_Op then |
| Append (Left_Opnd (N), Actuals); |
| end if; |
| |
| Append (Right_Opnd (N), Actuals); |
| |
| New_N := |
| Make_Function_Call (Sloc => Loc, |
| Name => New_Occurrence_Of (Nam, Loc), |
| Parameter_Associations => Actuals); |
| |
| Preserve_Comes_From_Source (New_N, N); |
| Preserve_Comes_From_Source (Name (New_N), N); |
| Rewrite (N, New_N); |
| Set_Etype (N, Etype (Nam)); |
| end Rewrite_Operator_As_Call; |
| |
| ------------------------------ |
| -- Rewrite_Renamed_Operator -- |
| ------------------------------ |
| |
| procedure Rewrite_Renamed_Operator (N : Node_Id; Op : Entity_Id) is |
| Nam : constant Name_Id := Chars (Op); |
| Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op; |
| Op_Node : Node_Id; |
| |
| begin |
| -- Rewrite the operator node using the real operator, not its |
| -- renaming. Exclude user-defined intrinsic operations, which |
| -- are treated separately. |
| |
| if Ekind (Op) /= E_Function then |
| Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N)); |
| Set_Chars (Op_Node, Nam); |
| Set_Etype (Op_Node, Etype (N)); |
| Set_Entity (Op_Node, Op); |
| Set_Right_Opnd (Op_Node, Right_Opnd (N)); |
| |
| -- Indicate that both the original entity and its renaming |
| -- are referenced at this point. |
| |
| Generate_Reference (Entity (N), N); |
| Generate_Reference (Op, N); |
| |
| if Is_Binary then |
| Set_Left_Opnd (Op_Node, Left_Opnd (N)); |
| end if; |
| |
| Rewrite (N, Op_Node); |
| end if; |
| end Rewrite_Renamed_Operator; |
| |
| ----------------------- |
| -- Set_Slice_Subtype -- |
| ----------------------- |
| |
| -- Build an implicit subtype declaration to represent the type delivered |
| -- by the slice. This is an abbreviated version of an array subtype. We |
| -- define an index subtype for the slice, using either the subtype name |
| -- or the discrete range of the slice. To be consistent with index usage |
| -- elsewhere, we create a list header to hold the single index. This list |
| -- is not otherwise attached to the syntax tree. |
| |
| procedure Set_Slice_Subtype (N : Node_Id) is |
| Loc : constant Source_Ptr := Sloc (N); |
| Index_List : constant List_Id := New_List; |
| Index : Node_Id; |
| Index_Subtype : Entity_Id; |
| Index_Type : Entity_Id; |
| Slice_Subtype : Entity_Id; |
| Drange : constant Node_Id := Discrete_Range (N); |
| |
| begin |
| if Is_Entity_Name (Drange) then |
| Index_Subtype := Entity (Drange); |
| |
| else |
| -- We force the evaluation of a range. This is definitely needed in |
| -- the renamed case, and seems safer to do unconditionally. Note in |
| -- any case that since we will create and insert an Itype referring |
| -- to this range, we must make sure any side effect removal actions |
| -- are inserted before the Itype definition. |
| |
| if Nkind (Drange) = N_Range then |
| Force_Evaluation (Low_Bound (Drange)); |
| Force_Evaluation (High_Bound (Drange)); |
| end if; |
| |
| Index_Type := Base_Type (Etype (Drange)); |
| |
| Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N); |
| |
| Set_Scalar_Range (Index_Subtype, Drange); |
| Set_Etype (Index_Subtype, Index_Type); |
| Set_Size_Info (Index_Subtype, Index_Type); |
| Set_RM_Size (Index_Subtype, RM_Size (Index_Type)); |
| end if; |
| |
| Slice_Subtype := Create_Itype (E_Array_Subtype, N); |
| |
| Index := New_Occurrence_Of (Index_Subtype, Loc); |
| Set_Etype (Index, Index_Subtype); |
| Append (Index, Index_List); |
| |
| Set_First_Index (Slice_Subtype, Index); |
| Set_Etype (Slice_Subtype, Base_Type (Etype (N))); |
| Set_Is_Constrained (Slice_Subtype, True); |
| Init_Size_Align (Slice_Subtype); |
| |
| Check_Compile_Time_Size (Slice_Subtype); |
| |
| -- The Etype of the existing Slice node is reset to this slice |
| -- subtype. Its bounds are obtained from its first index. |
| |
| Set_Etype (N, Slice_Subtype); |
| |
| -- In the packed case, this must be immediately frozen |
| |
| -- Couldn't we always freeze here??? and if we did, then the above |
| -- call to Check_Compile_Time_Size could be eliminated, which would |
| -- be nice, because then that routine could be made private to Freeze. |
| |
| if Is_Packed (Slice_Subtype) and not In_Default_Expression then |
| Freeze_Itype (Slice_Subtype, N); |
| end if; |
| |
| end Set_Slice_Subtype; |
| |
| -------------------------------- |
| -- Set_String_Literal_Subtype -- |
| -------------------------------- |
| |
| procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is |
| Subtype_Id : Entity_Id; |
| |
| begin |
| if Nkind (N) /= N_String_Literal then |
| return; |
| else |
| Subtype_Id := Create_Itype (E_String_Literal_Subtype, N); |
| end if; |
| |
| Set_String_Literal_Length (Subtype_Id, UI_From_Int |
| (String_Length (Strval (N)))); |
| Set_Etype (Subtype_Id, Base_Type (Typ)); |
| Set_Is_Constrained (Subtype_Id); |
| |
| -- The low bound is set from the low bound of the corresponding |
| -- index type. Note that we do not store the high bound in the |
| -- string literal subtype, but it can be deduced if necssary |
| -- from the length and the low bound. |
| |
| Set_String_Literal_Low_Bound |
| (Subtype_Id, Type_Low_Bound (Etype (First_Index (Typ)))); |
| |
| Set_Etype (N, Subtype_Id); |
| end Set_String_Literal_Subtype; |
| |
| ----------------------------- |
| -- Unique_Fixed_Point_Type -- |
| ----------------------------- |
| |
| function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is |
| T1 : Entity_Id := Empty; |
| T2 : Entity_Id; |
| Item : Node_Id; |
| Scop : Entity_Id; |
| |
| procedure Fixed_Point_Error; |
| -- If true ambiguity, give details. |
| |
| procedure Fixed_Point_Error is |
| begin |
| Error_Msg_N ("ambiguous universal_fixed_expression", N); |
| Error_Msg_NE ("\possible interpretation as}", N, T1); |
| Error_Msg_NE ("\possible interpretation as}", N, T2); |
| end Fixed_Point_Error; |
| |
| begin |
| -- The operations on Duration are visible, so Duration is always a |
| -- possible interpretation. |
| |
| T1 := Standard_Duration; |
| |
| -- Look for fixed-point types in enclosing scopes. |
| |
| Scop := Current_Scope; |
| while Scop /= Standard_Standard loop |
| T2 := First_Entity (Scop); |
| |
| while Present (T2) loop |
| if Is_Fixed_Point_Type (T2) |
| and then Current_Entity (T2) = T2 |
| and then Scope (Base_Type (T2)) = Scop |
| then |
| if Present (T1) then |
| Fixed_Point_Error; |
| return Any_Type; |
| else |
| T1 := T2; |
| end if; |
| end if; |
| |
| Next_Entity (T2); |
| end loop; |
| |
| Scop := Scope (Scop); |
| end loop; |
| |
| -- Look for visible fixed type declarations in the context. |
| |
| Item := First (Context_Items (Cunit (Current_Sem_Unit))); |
| |
| while Present (Item) loop |
| if Nkind (Item) = N_With_Clause then |
| Scop := Entity (Name (Item)); |
| T2 := First_Entity (Scop); |
| |
| while Present (T2) loop |
| if Is_Fixed_Point_Type (T2) |
| and then Scope (Base_Type (T2)) = Scop |
| and then (Is_Potentially_Use_Visible (T2) |
| or else In_Use (T2)) |
| then |
| if Present (T1) then |
| Fixed_Point_Error; |
| return Any_Type; |
| else |
| T1 := T2; |
| end if; |
| end if; |
| |
| Next_Entity (T2); |
| end loop; |
| end if; |
| |
| Next (Item); |
| end loop; |
| |
| if Nkind (N) = N_Real_Literal then |
| Error_Msg_NE ("real literal interpreted as }?", N, T1); |
| |
| else |
| Error_Msg_NE ("universal_fixed expression interpreted as }?", N, T1); |
| end if; |
| |
| return T1; |
| end Unique_Fixed_Point_Type; |
| |
| ---------------------- |
| -- Valid_Conversion -- |
| ---------------------- |
| |
| function Valid_Conversion |
| (N : Node_Id; |
| Target : Entity_Id; |
| Operand : Node_Id) |
| return Boolean |
| is |
| Target_Type : constant Entity_Id := Base_Type (Target); |
| Opnd_Type : Entity_Id := Etype (Operand); |
| |
| function Conversion_Check |
| (Valid : Boolean; |
| Msg : String) |
| return Boolean; |
| -- Little routine to post Msg if Valid is False, returns Valid value |
| |
| function Valid_Tagged_Conversion |
| (Target_Type : Entity_Id; |
| Opnd_Type : Entity_Id) |
| return Boolean; |
| -- Specifically test for validity of tagged conversions |
| |
| ---------------------- |
| -- Conversion_Check -- |
| ---------------------- |
| |
| function Conversion_Check |
| (Valid : Boolean; |
| Msg : String) |
| return Boolean |
| is |
| begin |
| if not Valid then |
| Error_Msg_N (Msg, Operand); |
| end if; |
| |
| return Valid; |
| end Conversion_Check; |
| |
| ----------------------------- |
| -- Valid_Tagged_Conversion -- |
| ----------------------------- |
| |
| function Valid_Tagged_Conversion |
| (Target_Type : Entity_Id; |
| Opnd_Type : Entity_Id) |
| return Boolean |
| is |
| begin |
| -- Upward conversions are allowed (RM 4.6(22)). |
| |
| if Covers (Target_Type, Opnd_Type) |
| or else Is_Ancestor (Target_Type, Opnd_Type) |
| then |
| return True; |
| |
| -- Downward conversion are allowed if the operand is |
| -- is class-wide (RM 4.6(23)). |
| |
| elsif Is_Class_Wide_Type (Opnd_Type) |
| and then Covers (Opnd_Type, Target_Type) |
| then |
| return True; |
| |
| elsif Covers (Opnd_Type, Target_Type) |
| or else Is_Ancestor (Opnd_Type, Target_Type) |
| then |
| return |
| Conversion_Check (False, |
| "downward conversion of tagged objects not allowed"); |
| else |
| Error_Msg_NE |
| ("invalid tagged conversion, not compatible with}", |
| N, First_Subtype (Opnd_Type)); |
| return False; |
| end if; |
| end Valid_Tagged_Conversion; |
| |
| -- Start of processing for Valid_Conversion |
| |
| begin |
| Check_Parameterless_Call (Operand); |
| |
| if Is_Overloaded (Operand) then |
| declare |
| I : Interp_Index; |
| I1 : Interp_Index; |
| It : Interp; |
| It1 : Interp; |
| N1 : Entity_Id; |
| |
| begin |
| -- Remove procedure calls, which syntactically cannot appear |
| -- in this context, but which cannot be removed by type checking, |
| -- because the context does not impose a type. |
| |
| Get_First_Interp (Operand, I, It); |
| |
| while Present (It.Typ) loop |
| |
| if It.Typ = Standard_Void_Type then |
| Remove_Interp (I); |
| end if; |
| |
| Get_Next_Interp (I, It); |
| end loop; |
| |
| Get_First_Interp (Operand, I, It); |
| I1 := I; |
| It1 := It; |
| |
| if No (It.Typ) then |
| Error_Msg_N ("illegal operand in conversion", Operand); |
| return False; |
| end if; |
| |
| Get_Next_Interp (I, It); |
| |
| if Present (It.Typ) then |
| N1 := It1.Nam; |
| It1 := Disambiguate (Operand, I1, I, Any_Type); |
| |
| if It1 = No_Interp then |
| Error_Msg_N ("ambiguous operand in conversion", Operand); |
| |
| Error_Msg_Sloc := Sloc (It.Nam); |
| Error_Msg_N ("possible interpretation#!", Operand); |
| |
| Error_Msg_Sloc := Sloc (N1); |
| Error_Msg_N ("possible interpretation#!", Operand); |
| |
| return False; |
| end if; |
| end if; |
| |
| Set_Etype (Operand, It1.Typ); |
| Opnd_Type := It1.Typ; |
| end; |
| end if; |
| |
| if Chars (Current_Scope) = Name_Unchecked_Conversion then |
| |
| -- This check is dubious, what if there were a user defined |
| -- scope whose name was Unchecked_Conversion ??? |
| |
| return True; |
| |
| elsif Is_Numeric_Type (Target_Type) then |
| if Opnd_Type = Universal_Fixed then |
| return True; |
| else |
| return Conversion_Check (Is_Numeric_Type (Opnd_Type), |
| "illegal operand for numeric conversion"); |
| end if; |
| |
| elsif Is_Array_Type (Target_Type) then |
| if not Is_Array_Type (Opnd_Type) |
| or else Opnd_Type = Any_Composite |
| or else Opnd_Type = Any_String |
| then |
| Error_Msg_N |
| ("illegal operand for array conversion", Operand); |
| return False; |
| |
| elsif Number_Dimensions (Target_Type) /= |
| Number_Dimensions (Opnd_Type) |
| then |
| Error_Msg_N |
| ("incompatible number of dimensions for conversion", Operand); |
| return False; |
| |
| else |
| declare |
| Target_Index : Node_Id := First_Index (Target_Type); |
| Opnd_Index : Node_Id := First_Index (Opnd_Type); |
| |
| Target_Index_Type : Entity_Id; |
| Opnd_Index_Type : Entity_Id; |
| |
| Target_Comp_Type : constant Entity_Id := |
| Component_Type (Target_Type); |
| Opnd_Comp_Type : constant Entity_Id := |
| Component_Type (Opnd_Type); |
| |
| begin |
| while Present (Target_Index) and then Present (Opnd_Index) loop |
| Target_Index_Type := Etype (Target_Index); |
| Opnd_Index_Type := Etype (Opnd_Index); |
| |
| if not (Is_Integer_Type (Target_Index_Type) |
| and then Is_Integer_Type (Opnd_Index_Type)) |
| and then (Root_Type (Target_Index_Type) |
| /= Root_Type (Opnd_Index_Type)) |
| then |
| Error_Msg_N |
| ("incompatible index types for array conversion", |
| Operand); |
| return False; |
| end if; |
| |
| Next_Index (Target_Index); |
| Next_Index (Opnd_Index); |
| end loop; |
| |
| if Base_Type (Target_Comp_Type) /= |
| Base_Type (Opnd_Comp_Type) |
| then |
| Error_Msg_N |
| ("incompatible component types for array conversion", |
| Operand); |
| return False; |
| |
| elsif |
| Is_Constrained (Target_Comp_Type) |
| /= Is_Constrained (Opnd_Comp_Type) |
| or else not Subtypes_Statically_Match |
| (Target_Comp_Type, Opnd_Comp_Type) |
| then |
| Error_Msg_N |
| ("component subtypes must statically match", Operand); |
| return False; |
| |
| end if; |
| end; |
| end if; |
| |
| return True; |
| |
| elsif (Ekind (Target_Type) = E_General_Access_Type |
| or else Ekind (Target_Type) = E_Anonymous_Access_Type) |
| and then |
| Conversion_Check |
| (Is_Access_Type (Opnd_Type) |
| and then Ekind (Opnd_Type) /= |
| E_Access_Subprogram_Type |
| and then Ekind (Opnd_Type) /= |
| E_Access_Protected_Subprogram_Type, |
| "must be an access-to-object type") |
| then |
| if Is_Access_Constant (Opnd_Type) |
| and then not Is_Access_Constant (Target_Type) |
| then |
| Error_Msg_N |
| ("access-to-constant operand type not allowed", Operand); |
| return False; |
| end if; |
| |
| -- Check the static accessibility rule of 4.6(17). Note that |
| -- the check is not enforced when within an instance body, since |
| -- the RM requires such cases to be caught at run time. |
| |
| if Ekind (Target_Type) /= E_Anonymous_Access_Type then |
| if Type_Access_Level (Opnd_Type) |
| > Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we |
| -- know will fail, so generate an appropriate warning. |
| -- The raise will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_N |
| ("?cannot convert local pointer to non-local access type", |
| Operand); |
| Error_Msg_N |
| ("?Program_Error will be raised at run time", Operand); |
| |
| else |
| Error_Msg_N |
| ("cannot convert local pointer to non-local access type", |
| Operand); |
| return False; |
| end if; |
| |
| elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type then |
| |
| -- When the operand is a selected access discriminant |
| -- the check needs to be made against the level of the |
| -- object denoted by the prefix of the selected name. |
| -- (Object_Access_Level handles checking the prefix |
| -- of the operand for this case.) |
| |
| if Nkind (Operand) = N_Selected_Component |
| and then Object_Access_Level (Operand) |
| > Type_Access_Level (Target_Type) |
| then |
| -- In an instance, this is a run-time check, but one we |
| -- know will fail, so generate an appropriate warning. |
| -- The raise will be generated by Expand_N_Type_Conversion. |
| |
| if In_Instance_Body then |
| Error_Msg_N |
| ("?cannot convert access discriminant to non-local" & |
| " access type", Operand); |
| Error_Msg_N |
| ("?Program_Error will be raised at run time", Operand); |
| |
| else |
| Error_Msg_N |
| ("cannot convert access discriminant to non-local" & |
| " access type", Operand); |
| return False; |
| end if; |
| end if; |
| |
| -- The case of a reference to an access discriminant |
| -- from within a type declaration (which will appear |
| -- as a discriminal) is always illegal because the |
| -- level of the discriminant is considered to be |
| -- deeper than any (namable) access type. |
| |
| if Is_Entity_Name (Operand) |
| and then (Ekind (Entity (Operand)) = E_In_Parameter |
| or else Ekind (Entity (Operand)) = E_Constant) |
| and then Present (Discriminal_Link (Entity (Operand))) |
| then |
| Error_Msg_N |
| ("discriminant has deeper accessibility level than target", |
| Operand); |
| return False; |
| end if; |
| end if; |
| end if; |
| |
| declare |
| Target : constant Entity_Id := Designated_Type (Target_Type); |
| Opnd : constant Entity_Id := Designated_Type (Opnd_Type); |
| |
| begin |
| if Is_Tagged_Type (Target) then |
| return Valid_Tagged_Conversion (Target, Opnd); |
| |
| else |
| if Base_Type (Target) /= Base_Type (Opnd) then |
| Error_Msg_NE |
| ("target designated type not compatible with }", |
| N, Base_Type (Opnd)); |
| return False; |
| |
| elsif not Subtypes_Statically_Match (Target, Opnd) |
| and then (not Has_Discriminants (Target) |
| or else Is_Constrained (Target)) |
| then |
| Error_Msg_NE |
| ("target designated subtype not compatible with }", |
| N, Opnd); |
| return False; |
| |
| else |
| return True; |
| end if; |
| end if; |
| end; |
| |
| elsif Ekind (Target_Type) = E_Access_Subprogram_Type |
| and then Conversion_Check |
| (Ekind (Base_Type (Opnd_Type)) = E_Access_Subprogram_Type, |
| "illegal operand for access subprogram conversion") |
| then |
| -- Check that the designated types are subtype conformant |
| |
| if not Subtype_Conformant (Designated_Type (Opnd_Type), |
| Designated_Type (Target_Type)) |
| then |
| Error_Msg_N |
| ("operand type is not subtype conformant with target type", |
| Operand); |
| end if; |
| |
| -- Check the static accessibility rule of 4.6(20) |
| |
| if Type_Access_Level (Opnd_Type) > |
| Type_Access_Level (Target_Type) |
| then |
| Error_Msg_N |
| ("operand type has deeper accessibility level than target", |
| Operand); |
| |
| -- Check that if the operand type is declared in a generic body, |
| -- then the target type must be declared within that same body |
| -- (enforces last sentence of 4.6(20)). |
| |
| elsif Present (Enclosing_Generic_Body (Opnd_Type)) then |
| declare |
| O_Gen : constant Node_Id := |
| Enclosing_Generic_Body (Opnd_Type); |
| |
| T_Gen : Node_Id := |
| Enclosing_Generic_Body (Target_Type); |
| |
| begin |
| while Present (T_Gen) and then T_Gen /= O_Gen loop |
| T_Gen := Enclosing_Generic_Body (T_Gen); |
| end loop; |
| |
| if T_Gen /= O_Gen then |
| Error_Msg_N |
| ("target type must be declared in same generic body" |
| & " as operand type", N); |
| end if; |
| end; |
| end if; |
| |
| return True; |
| |
| elsif Is_Remote_Access_To_Subprogram_Type (Target_Type) |
| and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type) |
| then |
| -- It is valid to convert from one RAS type to another provided |
| -- that their specification statically match. |
| |
| Check_Subtype_Conformant |
| (New_Id => |
| Designated_Type (Corresponding_Remote_Type (Target_Type)), |
| Old_Id => |
| Designated_Type (Corresponding_Remote_Type (Opnd_Type)), |
| Err_Loc => |
| N); |
| return True; |
| |
| elsif Is_Tagged_Type (Target_Type) then |
| return Valid_Tagged_Conversion (Target_Type, Opnd_Type); |
| |
| -- Types derived from the same root type are convertible. |
| |
| elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then |
| return True; |
| |
| -- In an instance, there may be inconsistent views of the same |
| -- type, or types derived from the same type. |
| |
| elsif In_Instance |
| and then Underlying_Type (Target_Type) = Underlying_Type (Opnd_Type) |
| then |
| return True; |
| |
| -- Special check for common access type error case |
| |
| elsif Ekind (Target_Type) = E_Access_Type |
| and then Is_Access_Type (Opnd_Type) |
| then |
| Error_Msg_N ("target type must be general access type!", N); |
| Error_Msg_NE ("add ALL to }!", N, Target_Type); |
| |
| return False; |
| |
| else |
| Error_Msg_NE ("invalid conversion, not compatible with }", |
| N, Opnd_Type); |
| |
| return False; |
| end if; |
| end Valid_Conversion; |
| |
| end Sem_Res; |