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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 4 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Debug; use Debug;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Util; use Exp_Util;
with Itypes; use Itypes;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Namet.Sp; use Namet.Sp;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Case; use Sem_Case;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Snames; use Snames;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch4 is
-- Tables which speed up the identification of dangerous calls to Ada 2012
-- functions with writable actuals (AI05-0144).
-- The following table enumerates the Ada constructs which may evaluate in
-- arbitrary order. It does not cover all the language constructs which can
-- be evaluated in arbitrary order but the subset needed for AI05-0144.
Has_Arbitrary_Evaluation_Order : constant array (Node_Kind) of Boolean :=
(N_Aggregate => True,
N_Assignment_Statement => True,
N_Entry_Call_Statement => True,
N_Extension_Aggregate => True,
N_Full_Type_Declaration => True,
N_Indexed_Component => True,
N_Object_Declaration => True,
N_Pragma => True,
N_Range => True,
N_Slice => True,
N_Array_Type_Definition => True,
N_Membership_Test => True,
N_Binary_Op => True,
N_Subprogram_Call => True,
others => False);
-- The following table enumerates the nodes on which we stop climbing when
-- locating the outermost Ada construct that can be evaluated in arbitrary
-- order.
Stop_Subtree_Climbing : constant array (Node_Kind) of Boolean :=
(N_Aggregate => True,
N_Assignment_Statement => True,
N_Entry_Call_Statement => True,
N_Extended_Return_Statement => True,
N_Extension_Aggregate => True,
N_Full_Type_Declaration => True,
N_Object_Declaration => True,
N_Object_Renaming_Declaration => True,
N_Package_Specification => True,
N_Pragma => True,
N_Procedure_Call_Statement => True,
N_Simple_Return_Statement => True,
N_Has_Condition => True,
others => False);
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Concatenation_Rest (N : Node_Id);
-- Does the "rest" of the work of Analyze_Concatenation, after the left
-- operand has been analyzed. See Analyze_Concatenation for details.
procedure Analyze_Expression (N : Node_Id);
-- For expressions that are not names, this is just a call to analyze. If
-- the expression is a name, it may be a call to a parameterless function,
-- and if so must be converted into an explicit call node and analyzed as
-- such. This deproceduring must be done during the first pass of overload
-- resolution, because otherwise a procedure call with overloaded actuals
-- may fail to resolve.
procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id);
-- Analyze a call of the form "+"(x, y), etc. The prefix of the call is an
-- operator name or an expanded name whose selector is an operator name,
-- and one possible interpretation is as a predefined operator.
procedure Analyze_Overloaded_Selected_Component (N : Node_Id);
-- If the prefix of a selected_component is overloaded, the proper
-- interpretation that yields a record type with the proper selector
-- name must be selected.
procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id);
-- Procedure to analyze a user defined binary operator, which is resolved
-- like a function, but instead of a list of actuals it is presented
-- with the left and right operands of an operator node.
procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id);
-- Procedure to analyze a user defined unary operator, which is resolved
-- like a function, but instead of a list of actuals, it is presented with
-- the operand of the operator node.
procedure Ambiguous_Operands (N : Node_Id);
-- For equality, membership, and comparison operators with overloaded
-- arguments, list possible interpretations.
procedure Analyze_One_Call
(N : Node_Id;
Nam : Entity_Id;
Report : Boolean;
Success : out Boolean;
Skip_First : Boolean := False);
-- Check one interpretation of an overloaded subprogram name for
-- compatibility with the types of the actuals in a call. If there is a
-- single interpretation which does not match, post error if Report is
-- set to True.
--
-- Nam is the entity that provides the formals against which the actuals
-- are checked. Nam is either the name of a subprogram, or the internal
-- subprogram type constructed for an access_to_subprogram. If the actuals
-- are compatible with Nam, then Nam is added to the list of candidate
-- interpretations for N, and Success is set to True.
--
-- The flag Skip_First is used when analyzing a call that was rewritten
-- from object notation. In this case the first actual may have to receive
-- an explicit dereference, depending on the first formal of the operation
-- being called. The caller will have verified that the object is legal
-- for the call. If the remaining parameters match, the first parameter
-- will rewritten as a dereference if needed, prior to completing analysis.
procedure Check_Misspelled_Selector
(Prefix : Entity_Id;
Sel : Node_Id);
-- Give possible misspelling message if Sel seems likely to be a mis-
-- spelling of one of the selectors of the Prefix. This is called by
-- Analyze_Selected_Component after producing an invalid selector error
-- message.
function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean;
-- Verify that type T is declared in scope S. Used to find interpretations
-- for operators given by expanded names. This is abstracted as a separate
-- function to handle extensions to System, where S is System, but T is
-- declared in the extension.
procedure Find_Arithmetic_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- L and R are the operands of an arithmetic operator. Find consistent
-- pairs of interpretations for L and R that have a numeric type consistent
-- with the semantics of the operator.
procedure Find_Comparison_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- L and R are operands of a comparison operator. Find consistent pairs of
-- interpretations for L and R.
procedure Find_Concatenation_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- For the four varieties of concatenation
procedure Find_Equality_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Ditto for equality operators
procedure Find_Boolean_Types
(L, R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Ditto for binary logical operations
procedure Find_Negation_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Find consistent interpretation for operand of negation operator
procedure Find_Non_Universal_Interpretations
(N : Node_Id;
R : Node_Id;
Op_Id : Entity_Id;
T1 : Entity_Id);
-- For equality and comparison operators, the result is always boolean, and
-- the legality of the operation is determined from the visibility of the
-- operand types. If one of the operands has a universal interpretation,
-- the legality check uses some compatible non-universal interpretation of
-- the other operand. N can be an operator node, or a function call whose
-- name is an operator designator. Any_Access, which is the initial type of
-- the literal NULL, is a universal type for the purpose of this routine.
function Find_Primitive_Operation (N : Node_Id) return Boolean;
-- Find candidate interpretations for the name Obj.Proc when it appears in
-- a subprogram renaming declaration.
procedure Find_Unary_Types
(R : Node_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Unary arithmetic types: plus, minus, abs
procedure Check_Arithmetic_Pair
(T1, T2 : Entity_Id;
Op_Id : Entity_Id;
N : Node_Id);
-- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid types
-- for left and right operand. Determine whether they constitute a valid
-- pair for the given operator, and record the corresponding interpretation
-- of the operator node. The node N may be an operator node (the usual
-- case) or a function call whose prefix is an operator designator. In
-- both cases Op_Id is the operator name itself.
procedure Diagnose_Call (N : Node_Id; Nam : Node_Id);
-- Give detailed information on overloaded call where none of the
-- interpretations match. N is the call node, Nam the designator for
-- the overloaded entity being called.
function Junk_Operand (N : Node_Id) return Boolean;
-- Test for an operand that is an inappropriate entity (e.g. a package
-- name or a label). If so, issue an error message and return True. If
-- the operand is not an inappropriate entity kind, return False.
procedure Operator_Check (N : Node_Id);
-- Verify that an operator has received some valid interpretation. If none
-- was found, determine whether a use clause would make the operation
-- legal. The variable Candidate_Type (defined in Sem_Type) is set for
-- every type compatible with the operator, even if the operator for the
-- type is not directly visible. The routine uses this type to emit a more
-- informative message.
function Has_Possible_Literal_Aspects (N : Node_Id) return Boolean;
-- Ada_2022: if an operand is a literal it may be subject to an
-- implicit conversion to a type for which a user-defined literal
-- function exists. During the first pass of type resolution we do
-- not know the context imposed on the literal, so we assume that
-- the literal type is a valid candidate and rely on the second pass
-- of resolution to find the type with the proper aspect. We only
-- add this interpretation if no other one was found, which may be
-- too restrictive but seems sufficient to handle most proper uses
-- of the new aspect. It is unclear whether a full implementation of
-- these aspects can be achieved without larger modifications to the
-- two-pass resolution algorithm.
procedure Remove_Abstract_Operations (N : Node_Id);
-- Ada 2005: implementation of AI-310. An abstract non-dispatching
-- operation is not a candidate interpretation.
function Try_Container_Indexing
(N : Node_Id;
Prefix : Node_Id;
Exprs : List_Id) return Boolean;
-- AI05-0139: Generalized indexing to support iterators over containers
-- ??? Need to provide a more detailed spec of what this function does
function Try_Indexed_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id;
Skip_First : Boolean) return Boolean;
-- If a function has defaults for all its actuals, a call to it may in fact
-- be an indexing on the result of the call. Try_Indexed_Call attempts the
-- interpretation as an indexing, prior to analysis as a call. If both are
-- possible, the node is overloaded with both interpretations (same symbol
-- but two different types). If the call is written in prefix form, the
-- prefix becomes the first parameter in the call, and only the remaining
-- actuals must be checked for the presence of defaults.
function Try_Indirect_Call
(N : Node_Id;
Nam : Entity_Id;
Typ : Entity_Id) return Boolean;
-- Similarly, a function F that needs no actuals can return an access to a
-- subprogram, and the call F (X) interpreted as F.all (X). In this case
-- the call may be overloaded with both interpretations.
procedure wpo (T : Entity_Id);
pragma Warnings (Off, wpo);
-- Used for debugging: obtain list of primitive operations even if
-- type is not frozen and dispatch table is not built yet.
------------------------
-- Ambiguous_Operands --
------------------------
procedure Ambiguous_Operands (N : Node_Id) is
procedure List_Operand_Interps (Opnd : Node_Id);
--------------------------
-- List_Operand_Interps --
--------------------------
procedure List_Operand_Interps (Opnd : Node_Id) is
Nam : Node_Id := Empty;
Err : Node_Id := N;
begin
if Is_Overloaded (Opnd) then
if Nkind (Opnd) in N_Op then
Nam := Opnd;
elsif Nkind (Opnd) = N_Function_Call then
Nam := Name (Opnd);
elsif Ada_Version >= Ada_2012 then
declare
It : Interp;
I : Interp_Index;
begin
Get_First_Interp (Opnd, I, It);
while Present (It.Nam) loop
if Has_Implicit_Dereference (It.Typ) then
Error_Msg_N
("can be interpreted as implicit dereference", Opnd);
return;
end if;
Get_Next_Interp (I, It);
end loop;
end;
return;
end if;
else
return;
end if;
if Opnd = Left_Opnd (N) then
Error_Msg_N
("\left operand has the following interpretations", N);
else
Error_Msg_N
("\right operand has the following interpretations", N);
Err := Opnd;
end if;
List_Interps (Nam, Err);
end List_Operand_Interps;
-- Start of processing for Ambiguous_Operands
begin
if Nkind (N) in N_Membership_Test then
Error_Msg_N ("ambiguous operands for membership", N);
elsif Nkind (N) in N_Op_Eq | N_Op_Ne then
Error_Msg_N ("ambiguous operands for equality", N);
else
Error_Msg_N ("ambiguous operands for comparison", N);
end if;
if All_Errors_Mode then
List_Operand_Interps (Left_Opnd (N));
List_Operand_Interps (Right_Opnd (N));
else
Error_Msg_N ("\use -gnatf switch for details", N);
end if;
end Ambiguous_Operands;
-----------------------
-- Analyze_Aggregate --
-----------------------
-- Most of the analysis of Aggregates requires that the type be known, and
-- is therefore put off until resolution of the context. Delta aggregates
-- have a base component that determines the enclosing aggregate type so
-- its type can be ascertained earlier. This also allows delta aggregates
-- to appear in the context of a record type with a private extension, as
-- per the latest update of AI12-0127.
procedure Analyze_Aggregate (N : Node_Id) is
begin
if No (Etype (N)) then
if Nkind (N) = N_Delta_Aggregate then
declare
Base : constant Node_Id := Expression (N);
I : Interp_Index;
It : Interp;
begin
Analyze (Base);
-- If the base is overloaded, propagate interpretations to the
-- enclosing aggregate.
if Is_Overloaded (Base) then
Get_First_Interp (Base, I, It);
Set_Etype (N, Any_Type);
while Present (It.Nam) loop
Add_One_Interp (N, It.Typ, It.Typ);
Get_Next_Interp (I, It);
end loop;
else
Set_Etype (N, Etype (Base));
end if;
end;
else
Set_Etype (N, Any_Composite);
end if;
end if;
end Analyze_Aggregate;
-----------------------
-- Analyze_Allocator --
-----------------------
procedure Analyze_Allocator (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Sav_Errs : constant Nat := Serious_Errors_Detected;
E : Node_Id := Expression (N);
Acc_Type : Entity_Id;
Type_Id : Entity_Id;
P : Node_Id;
C : Node_Id;
Onode : Node_Id;
begin
-- Deal with allocator restrictions
-- In accordance with H.4(7), the No_Allocators restriction only applies
-- to user-written allocators. The same consideration applies to the
-- No_Standard_Allocators_Before_Elaboration restriction.
if Comes_From_Source (N) then
Check_Restriction (No_Allocators, N);
-- Processing for No_Standard_Allocators_After_Elaboration, loop to
-- look at enclosing context, checking task/main subprogram case.
C := N;
P := Parent (C);
while Present (P) loop
-- For the task case we need a handled sequence of statements,
-- where the occurrence of the allocator is within the statements
-- and the parent is a task body
if Nkind (P) = N_Handled_Sequence_Of_Statements
and then Is_List_Member (C)
and then List_Containing (C) = Statements (P)
then
Onode := Original_Node (Parent (P));
-- Check for allocator within task body, this is a definite
-- violation of No_Allocators_After_Elaboration we can detect
-- at compile time.
if Nkind (Onode) = N_Task_Body then
Check_Restriction
(No_Standard_Allocators_After_Elaboration, N);
exit;
end if;
end if;
-- The other case is appearance in a subprogram body. This is
-- a violation if this is a library level subprogram with no
-- parameters. Note that this is now a static error even if the
-- subprogram is not the main program (this is a change, in an
-- earlier version only the main program was affected, and the
-- check had to be done in the binder.
if Nkind (P) = N_Subprogram_Body
and then Nkind (Parent (P)) = N_Compilation_Unit
and then No (Parameter_Specifications (Specification (P)))
then
Check_Restriction
(No_Standard_Allocators_After_Elaboration, N);
end if;
C := P;
P := Parent (C);
end loop;
end if;
-- Ada 2012 (AI05-0111-3): Analyze the subpool_specification, if
-- any. The expected type for the name is any type. A non-overloading
-- rule then requires it to be of a type descended from
-- System.Storage_Pools.Subpools.Subpool_Handle.
-- This isn't exactly what the AI says, but it seems to be the right
-- rule. The AI should be fixed.???
declare
Subpool : constant Node_Id := Subpool_Handle_Name (N);
begin
if Present (Subpool) then
Analyze (Subpool);
if Is_Overloaded (Subpool) then
Error_Msg_N ("ambiguous subpool handle", Subpool);
end if;
-- Check that Etype (Subpool) is descended from Subpool_Handle
Resolve (Subpool);
end if;
end;
-- Analyze the qualified expression or subtype indication
if Nkind (E) = N_Qualified_Expression then
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Find_Type (Subtype_Mark (E));
-- Analyze the qualified expression, and apply the name resolution
-- rule given in 4.7(3).
Analyze (E);
Type_Id := Etype (E);
Set_Directly_Designated_Type (Acc_Type, Type_Id);
-- A qualified expression requires an exact match of the type,
-- class-wide matching is not allowed.
-- if Is_Class_Wide_Type (Type_Id)
-- and then Base_Type
-- (Etype (Expression (E))) /= Base_Type (Type_Id)
-- then
-- Wrong_Type (Expression (E), Type_Id);
-- end if;
-- We don't analyze the qualified expression itself because it's
-- part of the allocator. It is fully analyzed and resolved when
-- the allocator is resolved with the context type.
Set_Etype (E, Type_Id);
-- Case where allocator has a subtype indication
else
declare
Def_Id : Entity_Id;
Base_Typ : Entity_Id;
begin
-- If the allocator includes a N_Subtype_Indication then a
-- constraint is present, otherwise the node is a subtype mark.
-- Introduce an explicit subtype declaration into the tree
-- defining some anonymous subtype and rewrite the allocator to
-- use this subtype rather than the subtype indication.
-- It is important to introduce the explicit subtype declaration
-- so that the bounds of the subtype indication are attached to
-- the tree in case the allocator is inside a generic unit.
-- Finally, if there is no subtype indication and the type is
-- a tagged unconstrained type with discriminants, the designated
-- object is constrained by their default values, and it is
-- simplest to introduce an explicit constraint now. In some cases
-- this is done during expansion, but freeze actions are certain
-- to be emitted in the proper order if constraint is explicit.
if Is_Entity_Name (E) and then Expander_Active then
Find_Type (E);
Type_Id := Entity (E);
if Is_Tagged_Type (Type_Id)
and then Has_Defaulted_Discriminants (Type_Id)
and then not Is_Constrained (Type_Id)
then
declare
Constr : constant List_Id := New_List;
Loc : constant Source_Ptr := Sloc (E);
Discr : Entity_Id := First_Discriminant (Type_Id);
begin
while Present (Discr) loop
Append (Discriminant_Default_Value (Discr), Constr);
Next_Discriminant (Discr);
end loop;
Rewrite (E,
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Type_Id, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => Constr)));
end;
end if;
end if;
if Nkind (E) = N_Subtype_Indication then
-- A constraint is only allowed for a composite type in Ada
-- 95. In Ada 83, a constraint is also allowed for an
-- access-to-composite type, but the constraint is ignored.
Find_Type (Subtype_Mark (E));
Base_Typ := Entity (Subtype_Mark (E));
if Is_Elementary_Type (Base_Typ) then
if not (Ada_Version = Ada_83
and then Is_Access_Type (Base_Typ))
then
Error_Msg_N ("constraint not allowed here", E);
if Nkind (Constraint (E)) =
N_Index_Or_Discriminant_Constraint
then
Error_Msg_N -- CODEFIX
("\if qualified expression was meant, " &
"use apostrophe", Constraint (E));
end if;
end if;
-- Get rid of the bogus constraint:
Rewrite (E, New_Copy_Tree (Subtype_Mark (E)));
Analyze_Allocator (N);
return;
end if;
-- In GNATprove mode we need to preserve the link between
-- the original subtype indication and the anonymous subtype,
-- to extend proofs to constrained access types. We only do
-- that outside of spec expressions, otherwise the declaration
-- cannot be inserted and analyzed. In such a case, GNATprove
-- later rejects the allocator as it is not used here in
-- a non-interfering context (SPARK 4.8(2) and 7.1.3(10)).
if Expander_Active
or else (GNATprove_Mode and then not In_Spec_Expression)
then
Def_Id := Make_Temporary (Loc, 'S');
Insert_Action (E,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Relocate_Node (E)));
if Sav_Errs /= Serious_Errors_Detected
and then Nkind (Constraint (E)) =
N_Index_Or_Discriminant_Constraint
then
Error_Msg_N -- CODEFIX
("if qualified expression was meant, "
& "use apostrophe!", Constraint (E));
end if;
E := New_Occurrence_Of (Def_Id, Loc);
Rewrite (Expression (N), E);
end if;
end if;
Type_Id := Process_Subtype (E, N);
Acc_Type := Create_Itype (E_Allocator_Type, N);
Set_Etype (Acc_Type, Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Type_Id);
Check_Fully_Declared (Type_Id, N);
-- Ada 2005 (AI-231): If the designated type is itself an access
-- type that excludes null, its default initialization will
-- be a null object, and we can insert an unconditional raise
-- before the allocator.
-- Ada 2012 (AI-104): A not null indication here is altogether
-- illegal.
if Can_Never_Be_Null (Type_Id) then
declare
Not_Null_Check : constant Node_Id :=
Make_Raise_Constraint_Error (Sloc (E),
Reason => CE_Null_Not_Allowed);
begin
if Expander_Active then
Insert_Action (N, Not_Null_Check);
Analyze (Not_Null_Check);
elsif Warn_On_Ada_2012_Compatibility then
Error_Msg_N
("null value not allowed here in Ada 2012?y?", E);
end if;
end;
end if;
-- Check for missing initialization. Skip this check if we already
-- had errors on analyzing the allocator, since in that case these
-- are probably cascaded errors.
if not Is_Definite_Subtype (Type_Id)
and then Serious_Errors_Detected = Sav_Errs
then
-- The build-in-place machinery may produce an allocator when
-- the designated type is indefinite but the underlying type is
-- not. In this case the unknown discriminants are meaningless
-- and should not trigger error messages. Check the parent node
-- because the allocator is marked as coming from source.
if Present (Underlying_Type (Type_Id))
and then Is_Definite_Subtype (Underlying_Type (Type_Id))
and then not Comes_From_Source (Parent (N))
then
null;
-- An unusual case arises when the parent of a derived type is
-- a limited record extension with unknown discriminants, and
-- its full view has no discriminants.
--
-- A more general fix might be to create the proper underlying
-- type for such a derived type, but it is a record type with
-- no private attributes, so this required extending the
-- meaning of this attribute. ???
elsif Ekind (Etype (Type_Id)) = E_Record_Type_With_Private
and then Present (Underlying_Type (Etype (Type_Id)))
and then
not Has_Discriminants (Underlying_Type (Etype (Type_Id)))
and then not Comes_From_Source (Parent (N))
then
null;
elsif Is_Class_Wide_Type (Type_Id) then
Error_Msg_N
("initialization required in class-wide allocation", N);
else
if Ada_Version < Ada_2005
and then Is_Limited_Type (Type_Id)
then
Error_Msg_N ("unconstrained allocation not allowed", N);
if Is_Array_Type (Type_Id) then
Error_Msg_N
("\constraint with array bounds required", N);
elsif Has_Unknown_Discriminants (Type_Id) then
null;
else pragma Assert (Has_Discriminants (Type_Id));
Error_Msg_N
("\constraint with discriminant values required", N);
end if;
-- Limited Ada 2005 and general nonlimited case.
-- This is an error, except in the case of an
-- uninitialized allocator that is generated
-- for a build-in-place function return of a
-- discriminated but compile-time-known-size
-- type.
else
if Original_Node (N) /= N
and then Nkind (Original_Node (N)) = N_Allocator
then
declare
Qual : constant Node_Id :=
Expression (Original_Node (N));
pragma Assert
(Nkind (Qual) = N_Qualified_Expression);
Call : constant Node_Id := Expression (Qual);
pragma Assert
(Is_Expanded_Build_In_Place_Call (Call));
begin
null;
end;
else
Error_Msg_N
("uninitialized unconstrained allocation not "
& "allowed", N);
if Is_Array_Type (Type_Id) then
Error_Msg_N
("\qualified expression or constraint with "
& "array bounds required", N);
elsif Has_Unknown_Discriminants (Type_Id) then
Error_Msg_N ("\qualified expression required", N);
else pragma Assert (Has_Discriminants (Type_Id));
Error_Msg_N
("\qualified expression or constraint with "
& "discriminant values required", N);
end if;
end if;
end if;
end if;
end if;
end;
end if;
if Is_Abstract_Type (Type_Id) then
Error_Msg_N ("cannot allocate abstract object", E);
end if;
if Has_Task (Designated_Type (Acc_Type)) then
Check_Restriction (No_Tasking, N);
Check_Restriction (Max_Tasks, N);
Check_Restriction (No_Task_Allocators, N);
end if;
-- Check restriction against dynamically allocated protected objects
if Has_Protected (Designated_Type (Acc_Type)) then
Check_Restriction (No_Protected_Type_Allocators, N);
end if;
-- AI05-0013-1: No_Nested_Finalization forbids allocators if the access
-- type is nested, and the designated type needs finalization. The rule
-- is conservative in that class-wide types need finalization.
if Needs_Finalization (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Nested_Finalization, N);
end if;
-- Check that an allocator of a nested access type doesn't create a
-- protected object when restriction No_Local_Protected_Objects applies.
if Has_Protected (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Local_Protected_Objects, N);
end if;
-- Likewise for No_Local_Timing_Events
if Has_Timing_Event (Designated_Type (Acc_Type))
and then not Is_Library_Level_Entity (Acc_Type)
then
Check_Restriction (No_Local_Timing_Events, N);
end if;
-- If the No_Streams restriction is set, check that the type of the
-- object is not, and does not contain, any subtype derived from
-- Ada.Streams.Root_Stream_Type. Note that we guard the call to
-- Has_Stream just for efficiency reasons. There is no point in
-- spending time on a Has_Stream check if the restriction is not set.
if Restriction_Check_Required (No_Streams) then
if Has_Stream (Designated_Type (Acc_Type)) then
Check_Restriction (No_Streams, N);
end if;
end if;
Set_Etype (N, Acc_Type);
if not Is_Library_Level_Entity (Acc_Type) then
Check_Restriction (No_Local_Allocators, N);
end if;
if Serious_Errors_Detected > Sav_Errs then
Set_Error_Posted (N);
Set_Etype (N, Any_Type);
end if;
end Analyze_Allocator;
---------------------------
-- Analyze_Arithmetic_Op --
---------------------------
procedure Analyze_Arithmetic_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id;
begin
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
-- If the entity is already set, the node is the instantiation of a
-- generic node with a non-local reference, or was manufactured by a
-- call to Make_Op_xxx. In either case the entity is known to be valid,
-- and we do not need to collect interpretations, instead we just get
-- the single possible interpretation.
Op_Id := Entity (N);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Set_Etype (N, Any_Type);
Find_Arithmetic_Types (L, R, Op_Id, N);
else
Set_Etype (N, Any_Type);
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
-- Entity is not already set, so we do need to collect interpretations
else
Set_Etype (N, Any_Type);
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator
and then Present (Next_Entity (First_Entity (Op_Id)))
then
Find_Arithmetic_Types (L, R, Op_Id, N);
-- The following may seem superfluous, because an operator cannot
-- be generic, but this ignores the cleverness of the author of
-- ACVC bc1013a.
elsif Is_Overloadable (Op_Id) then
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Arithmetic_Op;
------------------
-- Analyze_Call --
------------------
-- Function, procedure, and entry calls are checked here. The Name in
-- the call may be overloaded. The actuals have been analyzed and may
-- themselves be overloaded. On exit from this procedure, the node N
-- may have zero, one or more interpretations. In the first case an
-- error message is produced. In the last case, the node is flagged
-- as overloaded and the interpretations are collected in All_Interp.
-- If the name is an Access_To_Subprogram, it cannot be overloaded, but
-- the type-checking is similar to that of other calls.
procedure Analyze_Call (N : Node_Id) is
Actuals : constant List_Id := Parameter_Associations (N);
Loc : constant Source_Ptr := Sloc (N);
Nam : Node_Id;
X : Interp_Index;
It : Interp;
Nam_Ent : Entity_Id := Empty;
Success : Boolean := False;
Deref : Boolean := False;
-- Flag indicates whether an interpretation of the prefix is a
-- parameterless call that returns an access_to_subprogram.
procedure Check_Writable_Actuals (N : Node_Id);
-- If the call has out or in-out parameters then mark its outermost
-- enclosing construct as a node on which the writable actuals check
-- must be performed.
function Name_Denotes_Function return Boolean;
-- If the type of the name is an access to subprogram, this may be the
-- type of a name, or the return type of the function being called. If
-- the name is not an entity then it can denote a protected function.
-- Until we distinguish Etype from Return_Type, we must use this routine
-- to resolve the meaning of the name in the call.
procedure No_Interpretation;
-- Output error message when no valid interpretation exists
----------------------------
-- Check_Writable_Actuals --
----------------------------
-- The identification of conflicts in calls to functions with writable
-- actuals is performed in the analysis phase of the front end to ensure
-- that it reports exactly the same errors compiling with and without
-- expansion enabled. It is performed in two stages:
-- 1) When a call to a function with out-mode parameters is found,
-- we climb to the outermost enclosing construct that can be
-- evaluated in arbitrary order and we mark it with the flag
-- Check_Actuals.
-- 2) When the analysis of the marked node is complete, we traverse
-- its decorated subtree searching for conflicts (see function
-- Sem_Util.Check_Function_Writable_Actuals).
-- The unique exception to this general rule is for aggregates, since
-- their analysis is performed by the front end in the resolution
-- phase. For aggregates we do not climb to their enclosing construct:
-- we restrict the analysis to the subexpressions initializing the
-- aggregate components.
-- This implies that the analysis of expressions containing aggregates
-- is not complete, since there may be conflicts on writable actuals
-- involving subexpressions of the enclosing logical or arithmetic
-- expressions. However, we cannot wait and perform the analysis when
-- the whole subtree is resolved, since the subtrees may be transformed,
-- thus adding extra complexity and computation cost to identify and
-- report exactly the same errors compiling with and without expansion
-- enabled.
procedure Check_Writable_Actuals (N : Node_Id) is
begin
if Comes_From_Source (N)
and then Present (Get_Subprogram_Entity (N))
and then Has_Out_Or_In_Out_Parameter (Get_Subprogram_Entity (N))
then
-- For procedures and entries there is no need to climb since
-- we only need to check if the actuals of this call invoke
-- functions whose out-mode parameters overlap.
if Nkind (N) /= N_Function_Call then
Set_Check_Actuals (N);
-- For calls to functions we climb to the outermost enclosing
-- construct where the out-mode actuals of this function may
-- introduce conflicts.
else
declare
Outermost : Node_Id := Empty; -- init to avoid warning
P : Node_Id := N;
begin
while Present (P) loop
-- For object declarations we can climb to the node from
-- its object definition branch or from its initializing
-- expression. We prefer to mark the child node as the
-- outermost construct to avoid adding further complexity
-- to the routine that will later take care of
-- performing the writable actuals check.
if Has_Arbitrary_Evaluation_Order (Nkind (P))
and then Nkind (P) not in
N_Assignment_Statement | N_Object_Declaration
then
Outermost := P;
end if;
-- Avoid climbing more than needed
exit when Stop_Subtree_Climbing (Nkind (P))
or else (Nkind (P) = N_Range
and then
Nkind (Parent (P)) not in N_In | N_Not_In);
P := Parent (P);
end loop;
Set_Check_Actuals (Outermost);
end;
end if;
end if;
end Check_Writable_Actuals;
---------------------------
-- Name_Denotes_Function --
---------------------------
function Name_Denotes_Function return Boolean is
begin
if Is_Entity_Name (Nam) then
return Ekind (Entity (Nam)) = E_Function;
elsif Nkind (Nam) = N_Selected_Component then
return Ekind (Entity (Selector_Name (Nam))) = E_Function;
else
return False;
end if;
end Name_Denotes_Function;
-----------------------
-- No_Interpretation --
-----------------------
procedure No_Interpretation is
L : constant Boolean := Is_List_Member (N);
K : constant Node_Kind := Nkind (Parent (N));
begin
-- If the node is in a list whose parent is not an expression then it
-- must be an attempted procedure call.
if L and then K not in N_Subexpr then
if Ekind (Entity (Nam)) = E_Generic_Procedure then
Error_Msg_NE
("must instantiate generic procedure& before call",
Nam, Entity (Nam));
else
Error_Msg_N ("procedure or entry name expected", Nam);
end if;
-- Check for tasking cases where only an entry call will do
elsif not L
and then K in N_Entry_Call_Alternative | N_Triggering_Alternative
then
Error_Msg_N ("entry name expected", Nam);
-- Otherwise give general error message
else
Error_Msg_N ("invalid prefix in call", Nam);
end if;
end No_Interpretation;
-- Start of processing for Analyze_Call
begin
-- Initialize the type of the result of the call to the error type,
-- which will be reset if the type is successfully resolved.
Set_Etype (N, Any_Type);
Nam := Name (N);
if not Is_Overloaded (Nam) then
-- Only one interpretation to check
if Ekind (Etype (Nam)) = E_Subprogram_Type then
Nam_Ent := Etype (Nam);
-- If the prefix is an access_to_subprogram, this may be an indirect
-- call. This is the case if the name in the call is not an entity
-- name, or if it is a function name in the context of a procedure
-- call. In this latter case, we have a call to a parameterless
-- function that returns a pointer_to_procedure which is the entity
-- being called. Finally, F (X) may be a call to a parameterless
-- function that returns a pointer to a function with parameters.
-- Note that if F returns an access-to-subprogram whose designated
-- type is an array, F (X) cannot be interpreted as an indirect call
-- through the result of the call to F.
elsif Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
and then
(not Name_Denotes_Function
or else Nkind (N) = N_Procedure_Call_Statement
or else
(Nkind (Parent (N)) /= N_Explicit_Dereference
and then Is_Entity_Name (Nam)
and then No (First_Formal (Entity (Nam)))
and then not
Is_Array_Type (Etype (Designated_Type (Etype (Nam))))
and then Present (Actuals)))
then
Nam_Ent := Designated_Type (Etype (Nam));
Insert_Explicit_Dereference (Nam);
-- Selected component case. Simple entry or protected operation,
-- where the entry name is given by the selector name.
elsif Nkind (Nam) = N_Selected_Component then
Nam_Ent := Entity (Selector_Name (Nam));
if Ekind (Nam_Ent) not in E_Entry
| E_Entry_Family
| E_Function
| E_Procedure
then
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
end if;
-- If the name is an Indexed component, it can be a call to a member
-- of an entry family. The prefix must be a selected component whose
-- selector is the entry. Analyze_Procedure_Call normalizes several
-- kinds of call into this form.
elsif Nkind (Nam) = N_Indexed_Component then
if Nkind (Prefix (Nam)) = N_Selected_Component then
Nam_Ent := Entity (Selector_Name (Prefix (Nam)));
else
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
end if;
elsif not Is_Entity_Name (Nam) then
Error_Msg_N ("name in call is not a callable entity", Nam);
Set_Etype (N, Any_Type);
return;
else
Nam_Ent := Entity (Nam);
-- If not overloadable, this may be a generalized indexing
-- operation with named associations. Rewrite again as an
-- indexed component and analyze as container indexing.
if not Is_Overloadable (Nam_Ent) then
if Present
(Find_Value_Of_Aspect
(Etype (Nam_Ent), Aspect_Constant_Indexing))
then
Replace (N,
Make_Indexed_Component (Sloc (N),
Prefix => Nam,
Expressions => Parameter_Associations (N)));
if Try_Container_Indexing (N, Nam, Expressions (N)) then
return;
else
No_Interpretation;
end if;
else
No_Interpretation;
end if;
return;
end if;
end if;
-- Operations generated for RACW stub types are called only through
-- dispatching, and can never be the static interpretation of a call.
if Is_RACW_Stub_Type_Operation (Nam_Ent) then
No_Interpretation;
return;
end if;
Analyze_One_Call (N, Nam_Ent, True, Success);
-- If the nonoverloaded interpretation is a call to an abstract
-- nondispatching operation, then flag an error and return.
-- Should this be incorporated in Remove_Abstract_Operations (which
-- currently only deals with cases where the name is overloaded)? ???
if Is_Overloadable (Nam_Ent)
and then Is_Abstract_Subprogram (Nam_Ent)
and then not Is_Dispatching_Operation (Nam_Ent)
then
Set_Etype (N, Any_Type);
Error_Msg_Sloc := Sloc (Nam_Ent);
Error_Msg_NE
("cannot call abstract operation& declared#", N, Nam_Ent);
return;
end if;
-- If this is an indirect call, the return type of the access_to
-- subprogram may be an incomplete type. At the point of the call,
-- use the full type if available, and at the same time update the
-- return type of the access_to_subprogram.
if Success
and then Nkind (Nam) = N_Explicit_Dereference
and then Ekind (Etype (N)) = E_Incomplete_Type
and then Present (Full_View (Etype (N)))
then
Set_Etype (N, Full_View (Etype (N)));
Set_Etype (Nam_Ent, Etype (N));
end if;
-- Overloaded call
else
-- An overloaded selected component must denote overloaded operations
-- of a concurrent type. The interpretations are attached to the
-- simple name of those operations.
if Nkind (Nam) = N_Selected_Component then
Nam := Selector_Name (Nam);
end if;
Get_First_Interp (Nam, X, It);
while Present (It.Nam) loop
Nam_Ent := It.Nam;
Deref := False;
-- Name may be call that returns an access to subprogram, or more
-- generally an overloaded expression one of whose interpretations
-- yields an access to subprogram. If the name is an entity, we do
-- not dereference, because the node is a call that returns the
-- access type: note difference between f(x), where the call may
-- return an access subprogram type, and f(x)(y), where the type
-- returned by the call to f is implicitly dereferenced to analyze
-- the outer call.
if Is_Access_Type (Nam_Ent) then
Nam_Ent := Designated_Type (Nam_Ent);
elsif Is_Access_Type (Etype (Nam_Ent))
and then
(not Is_Entity_Name (Nam)
or else Nkind (N) = N_Procedure_Call_Statement)
and then Ekind (Designated_Type (Etype (Nam_Ent)))
= E_Subprogram_Type
then
Nam_Ent := Designated_Type (Etype (Nam_Ent));
if Is_Entity_Name (Nam) then
Deref := True;
end if;
end if;
-- If the call has been rewritten from a prefixed call, the first
-- parameter has been analyzed, but may need a subsequent
-- dereference, so skip its analysis now.
if Is_Rewrite_Substitution (N)
and then Nkind (Original_Node (N)) = Nkind (N)
and then Nkind (Name (N)) /= Nkind (Name (Original_Node (N)))
and then Present (Parameter_Associations (N))
and then Present (Etype (First (Parameter_Associations (N))))
then
Analyze_One_Call
(N, Nam_Ent, False, Success, Skip_First => True);
else
Analyze_One_Call (N, Nam_Ent, False, Success);
end if;
-- If the interpretation succeeds, mark the proper type of the
-- prefix (any valid candidate will do). If not, remove the
-- candidate interpretation. If this is a parameterless call
-- on an anonymous access to subprogram, X is a variable with
-- an access discriminant D, the entity in the interpretation is
-- D, so rewrite X as X.D.all.
if Success then
if Deref
and then Nkind (Parent (N)) /= N_Explicit_Dereference
then
if Ekind (It.Nam) = E_Discriminant
and then Has_Implicit_Dereference (It.Nam)
then
Rewrite (Name (N),
Make_Explicit_Dereference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
New_Occurrence_Of (Entity (Nam), Loc),
Selector_Name =>
New_Occurrence_Of (It.Nam, Loc))));
Analyze (N);
return;
else
Set_Entity (Nam, It.Nam);
Insert_Explicit_Dereference (Nam);
Set_Etype (Nam, Nam_Ent);
end if;
else
Set_Etype (Nam, It.Typ);
end if;
elsif Nkind (Name (N)) in N_Function_Call | N_Selected_Component
then
Remove_Interp (X);
end if;
Get_Next_Interp (X, It);
end loop;
-- If the name is the result of a function call, it can only be a
-- call to a function returning an access to subprogram. Insert
-- explicit dereference.
if Nkind (Nam) = N_Function_Call then
Insert_Explicit_Dereference (Nam);
end if;
if Etype (N) = Any_Type then
-- None of the interpretations is compatible with the actuals
Diagnose_Call (N, Nam);
-- Special checks for uninstantiated put routines
if Nkind (N) = N_Procedure_Call_Statement
and then Is_Entity_Name (Nam)
and then Chars (Nam) = Name_Put
and then List_Length (Actuals) = 1
then
declare
Arg : constant Node_Id := First (Actuals);
Typ : Entity_Id;
begin
if Nkind (Arg) = N_Parameter_Association then
Typ := Etype (Explicit_Actual_Parameter (Arg));
else
Typ := Etype (Arg);
end if;
if Is_Signed_Integer_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Integer_'I'O!", Nam);
elsif Is_Modular_Integer_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Modular_'I'O!", Nam);
elsif Is_Floating_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Float_'I'O!", Nam);
elsif Is_Ordinary_Fixed_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Fixed_'I'O!", Nam);
elsif Is_Decimal_Fixed_Point_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Decimal_'I'O!", Nam);
elsif Is_Enumeration_Type (Typ) then
Error_Msg_N
("possible missing instantiation of "
& "'Text_'I'O.'Enumeration_'I'O!", Nam);
end if;
end;
end if;
elsif not Is_Overloaded (N)
and then Is_Entity_Name (Nam)
then
-- Resolution yields a single interpretation. Verify that the
-- reference has capitalization consistent with the declaration.
Set_Entity_With_Checks (Nam, Entity (Nam));
Generate_Reference (Entity (Nam), Nam);
Set_Etype (Nam, Etype (Entity (Nam)));
else
Remove_Abstract_Operations (N);
end if;
end if;
-- Check the accessibility level for actuals for explicitly aliased
-- formals.
if Nkind (N) = N_Function_Call
and then Comes_From_Source (N)
and then Present (Nam_Ent)
and then In_Return_Value (N)
then
declare
Form : Node_Id;
Act : Node_Id;
begin
Act := First_Actual (N);
Form := First_Formal (Nam_Ent);
while Present (Form) and then Present (Act) loop
-- Check whether the formal is aliased and if the accessibility
-- level of the actual is deeper than the accessibility level
-- of the enclosing subprogam to which the current return
-- statement applies.
-- Should we be checking Is_Entity_Name on Act? Won't this miss
-- other cases ???
if Is_Explicitly_Aliased (Form)
and then Is_Entity_Name (Act)
and then Static_Accessibility_Level
(Act, Zero_On_Dynamic_Level)
> Subprogram_Access_Level (Current_Subprogram)
then
Error_Msg_N ("actual for explicitly aliased formal is too"
& " short lived", Act);
end if;
Next_Formal (Form);
Next_Actual (Act);
end loop;
end;
end if;
if Ada_Version >= Ada_2012 then
-- Check if the call contains a function with writable actuals
Check_Writable_Actuals (N);
-- If found and the outermost construct that can be evaluated in
-- an arbitrary order is precisely this call, then check all its
-- actuals.
Check_Function_Writable_Actuals (N);
-- The return type of the function may be incomplete. This can be
-- the case if the type is a generic formal, or a limited view. It
-- can also happen when the function declaration appears before the
-- full view of the type (which is legal in Ada 2012) and the call
-- appears in a different unit, in which case the incomplete view
-- must be replaced with the full view (or the nonlimited view)
-- to prevent subsequent type errors. Note that the usual install/
-- removal of limited_with clauses is not sufficient to handle this
-- case, because the limited view may have been captured in another
-- compilation unit that defines the current function.
if Is_Incomplete_Type (Etype (N)) then
if Present (Full_View (Etype (N))) then
if Is_Entity_Name (Nam) then
Set_Etype (Nam, Full_View (Etype (N)));
Set_Etype (Entity (Nam), Full_View (Etype (N)));
end if;
Set_Etype (N, Full_View (Etype (N)));
elsif From_Limited_With (Etype (N))
and then Present (Non_Limited_View (Etype (N)))
then
Set_Etype (N, Non_Limited_View (Etype (N)));
-- If there is no completion for the type, this may be because
-- there is only a limited view of it and there is nothing in
-- the context of the current unit that has required a regular
-- compilation of the unit containing the type. We recognize
-- this unusual case by the fact that unit is not analyzed.
-- Note that the call being analyzed is in a different unit from
-- the function declaration, and nothing indicates that the type
-- is a limited view.
elsif Ekind (Scope (Etype (N))) = E_Package
and then Present (Limited_View (Scope (Etype (N))))
and then not Analyzed (Unit_Declaration_Node (Scope (Etype (N))))
then
Error_Msg_NE
("cannot call function that returns limited view of}",
N, Etype (N));
Error_Msg_NE
("\there must be a regular with_clause for package & in the "
& "current unit, or in some unit in its context",
N, Scope (Etype (N)));
Set_Etype (N, Any_Type);
end if;
end if;
end if;
end Analyze_Call;
-----------------------------
-- Analyze_Case_Expression --
-----------------------------
procedure Analyze_Case_Expression (N : Node_Id) is
procedure Non_Static_Choice_Error (Choice : Node_Id);
-- Error routine invoked by the generic instantiation below when
-- the case expression has a non static choice.
package Case_Choices_Analysis is new
Generic_Analyze_Choices
(Process_Associated_Node => No_OP);
use Case_Choices_Analysis;
package Case_Choices_Checking is new
Generic_Check_Choices
(Process_Empty_Choice => No_OP,
Process_Non_Static_Choice => Non_Static_Choice_Error,
Process_Associated_Node => No_OP);
use Case_Choices_Checking;
-----------------------------
-- Non_Static_Choice_Error --
-----------------------------
procedure Non_Static_Choice_Error (Choice : Node_Id) is
begin
Flag_Non_Static_Expr
("choice given in case expression is not static!", Choice);
end Non_Static_Choice_Error;
-- Local variables
Expr : constant Node_Id := Expression (N);
Alt : Node_Id;
Exp_Type : Entity_Id;
Exp_Btype : Entity_Id;
FirstX : Node_Id := Empty;
-- First expression in the case for which there is some type information
-- available, i.e. it is not Any_Type, which can happen because of some
-- error, or from the use of e.g. raise Constraint_Error.
Others_Present : Boolean;
-- Indicates if Others was present
Wrong_Alt : Node_Id := Empty;
-- For error reporting
-- Start of processing for Analyze_Case_Expression
begin
if Comes_From_Source (N) then
Check_Compiler_Unit ("case expression", N);
end if;
Analyze_And_Resolve (Expr, Any_Discrete);
Check_Unset_Reference (Expr);
Exp_Type := Etype (Expr);
Exp_Btype := Base_Type (Exp_Type);
Alt := First (Alternatives (N));
while Present (Alt) loop
if Error_Posted (Expression (Alt)) then
return;
end if;
Analyze (Expression (Alt));
if No (FirstX) and then Etype (Expression (Alt)) /= Any_Type then
FirstX := Expression (Alt);
end if;
Next (Alt);
end loop;
-- Get our initial type from the first expression for which we got some
-- useful type information from the expression.
if No (FirstX) then
return;
end if;
if not Is_Overloaded (FirstX) then
Set_Etype (N, Etype (FirstX));
else
declare
I : Interp_Index;
It : Interp;
begin
Set_Etype (N, Any_Type);
Get_First_Interp (FirstX, I, It);
while Present (It.Nam) loop
-- For each interpretation of the first expression, we only
-- add the interpretation if every other expression in the
-- case expression alternatives has a compatible type.
Alt := Next (First (Alternatives (N)));
while Present (Alt) loop
exit when not Has_Compatible_Type (Expression (Alt), It.Typ);
Next (Alt);
end loop;
if No (Alt) then
Add_One_Interp (N, It.Typ, It.Typ);
else
Wrong_Alt := Alt;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
Exp_Btype := Base_Type (Exp_Type);
-- The expression must be of a discrete type which must be determinable
-- independently of the context in which the expression occurs, but
-- using the fact that the expression must be of a discrete type.
-- Moreover, the type this expression must not be a character literal
-- (which is always ambiguous).
-- If error already reported by Resolve, nothing more to do
if Exp_Btype = Any_Discrete or else Exp_Btype = Any_Type then
return;
-- Special casee message for character literal
elsif Exp_Btype = Any_Character then
Error_Msg_N
("character literal as case expression is ambiguous", Expr);
return;
end if;
if Etype (N) = Any_Type and then Present (Wrong_Alt) then
Error_Msg_N
("type incompatible with that of previous alternatives",
Expression (Wrong_Alt));
return;
end if;
-- If the case expression is a formal object of mode in out, then
-- treat it as having a nonstatic subtype by forcing use of the base
-- type (which has to get passed to Check_Case_Choices below). Also
-- use base type when the case expression is parenthesized.
if Paren_Count (Expr) > 0
or else (Is_Entity_Name (Expr)
and then Ekind (Entity (Expr)) = E_Generic_In_Out_Parameter)
then
Exp_Type := Exp_Btype;
end if;
-- The case expression alternatives cover the range of a static subtype
-- subject to aspect Static_Predicate. Do not check the choices when the
-- case expression has not been fully analyzed yet because this may lead
-- to bogus errors.
if Is_OK_Static_Subtype (Exp_Type)
and then Has_Static_Predicate_Aspect (Exp_Type)
and then In_Spec_Expression
then
null;
-- Call Analyze_Choices and Check_Choices to do the rest of the work
else
Analyze_Choices (Alternatives (N), Exp_Type);
Check_Choices (N, Alternatives (N), Exp_Type, Others_Present);
if Exp_Type = Universal_Integer and then not Others_Present then
Error_Msg_N
("case on universal integer requires OTHERS choice", Expr);
end if;
end if;
end Analyze_Case_Expression;
---------------------------
-- Analyze_Comparison_Op --
---------------------------
procedure Analyze_Comparison_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Comparison_Types (L, R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
if Is_Overloaded (L) then
Set_Etype (L, Intersect_Types (L, R));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Comparison_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Comparison_Op;
---------------------------
-- Analyze_Concatenation --
---------------------------
procedure Analyze_Concatenation (N : Node_Id) is
-- We wish to avoid deep recursion, because concatenations are often
-- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
-- operands nonrecursively until we find something that is not a
-- concatenation (A in this case), or has already been analyzed. We
-- analyze that, and then walk back up the tree following Parent
-- pointers, calling Analyze_Concatenation_Rest to do the rest of the
-- work at each level. The Parent pointers allow us to avoid recursion,
-- and thus avoid running out of memory.
NN : Node_Id := N;
L : Node_Id;
begin
Candidate_Type := Empty;
-- The following code is equivalent to:
-- Set_Etype (N, Any_Type);
-- Analyze_Expression (Left_Opnd (N));
-- Analyze_Concatenation_Rest (N);
-- where the Analyze_Expression call recurses back here if the left
-- operand is a concatenation.
-- Walk down left operands
loop
Set_Etype (NN, Any_Type);
L := Left_Opnd (NN);
exit when Nkind (L) /= N_Op_Concat or else Analyzed (L);
NN := L;
end loop;
-- Now (given the above example) NN is A&B and L is A
-- First analyze L ...
Analyze_Expression (L);
-- ... then walk NN back up until we reach N (where we started), calling
-- Analyze_Concatenation_Rest along the way.
loop
Analyze_Concatenation_Rest (NN);
exit when NN = N;
NN := Parent (NN);
end loop;
end Analyze_Concatenation;
--------------------------------
-- Analyze_Concatenation_Rest --
--------------------------------
-- If the only one-dimensional array type in scope is String,
-- this is the resulting type of the operation. Otherwise there
-- will be a concatenation operation defined for each user-defined
-- one-dimensional array.
procedure Analyze_Concatenation_Rest (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
LT : Entity_Id;
RT : Entity_Id;
begin
Analyze_Expression (R);
-- If the entity is present, the node appears in an instance, and
-- denotes a predefined concatenation operation. The resulting type is
-- obtained from the arguments when possible. If the arguments are
-- aggregates, the array type and the concatenation type must be
-- visible.
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
LT := Base_Type (Etype (L));
RT := Base_Type (Etype (R));
if Is_Array_Type (LT)
and then (RT = LT or else RT = Base_Type (Component_Type (LT)))
then
Add_One_Interp (N, Op_Id, LT);
elsif Is_Array_Type (RT)
and then LT = Base_Type (Component_Type (RT))
then
Add_One_Interp (N, Op_Id, RT);
-- If one operand is a string type or a user-defined array type,
-- and the other is a literal, result is of the specific type.
elsif
(Root_Type (LT) = Standard_String
or else Scope (LT) /= Standard_Standard)
and then Etype (R) = Any_String
then
Add_One_Interp (N, Op_Id, LT);
elsif
(Root_Type (RT) = Standard_String
or else Scope (RT) /= Standard_Standard)
and then Etype (L) = Any_String
then
Add_One_Interp (N, Op_Id, RT);
elsif not Is_Generic_Type (Etype (Op_Id)) then
Add_One_Interp (N, Op_Id, Etype (Op_Id));
else
-- Type and its operations must be visible
Set_Entity (N, Empty);
Analyze_Concatenation (N);
end if;
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Name_Op_Concat);
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
-- Do not consider operators declared in dead code, they
-- cannot be part of the resolution.
if Is_Eliminated (Op_Id) then
null;
else
Find_Concatenation_Types (L, R, Op_Id, N);
end if;
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
end Analyze_Concatenation_Rest;
-------------------------
-- Analyze_Equality_Op --
-------------------------
procedure Analyze_Equality_Op (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id;
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
-- If the entity is set, the node is a generic instance with a non-local
-- reference to the predefined operator or to a user-defined function.
-- It can also be an inequality that is expanded into the negation of a
-- call to a user-defined equality operator.
-- For the predefined case, the result is Boolean, regardless of the
-- type of the operands. The operands may even be limited, if they are
-- generic actuals. If they are overloaded, label the left argument with
-- the common type that must be present, or with the type of the formal
-- of the user-defined function.
if Present (Entity (N)) then
Op_Id := Entity (N);
if Ekind (Op_Id) = E_Operator then
Add_One_Interp (N, Op_Id, Standard_Boolean);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
if Is_Overloaded (L) then
if Ekind (Op_Id) = E_Operator then
Set_Etype (L, Intersect_Types (L, R));
else
Set_Etype (L, Etype (First_Formal (Op_Id)));
end if;
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Equality_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
-- If there was no match, and the operator is inequality, this may be
-- a case where inequality has not been made explicit, as for tagged
-- types. Analyze the node as the negation of an equality operation.
-- This cannot be done earlier, because before analysis we cannot rule
-- out the presence of an explicit inequality.
if Etype (N) = Any_Type
and then Nkind (N) = N_Op_Ne
then
Op_Id := Get_Name_Entity_Id (Name_Op_Eq);
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Equality_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
if Etype (N) /= Any_Type then
Op_Id := Entity (N);
Rewrite (N,
Make_Op_Not (Loc,
Right_Opnd =>
Make_Op_Eq (Loc,
Left_Opnd => Left_Opnd (N),
Right_Opnd => Right_Opnd (N))));
Set_Entity (Right_Opnd (N), Op_Id);
Analyze (N);
end if;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Equality_Op;
----------------------------------
-- Analyze_Explicit_Dereference --
----------------------------------
procedure Analyze_Explicit_Dereference (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
P : constant Node_Id := Prefix (N);
T : Entity_Id;
I : Interp_Index;
It : Interp;
New_N : Node_Id;
function Is_Function_Type return Boolean;
-- Check whether node may be interpreted as an implicit function call
----------------------
-- Is_Function_Type --
----------------------
function Is_Function_Type return Boolean is
I : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (N) then
return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type
and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type;
else
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type
or else Etype (Base_Type (It.Typ)) = Standard_Void_Type
then
return False;
end if;
Get_Next_Interp (I, It);
end loop;
return True;
end if;
end Is_Function_Type;
-- Start of processing for Analyze_Explicit_Dereference
begin
-- In formal verification mode, keep track of all reads and writes
-- through explicit dereferences.
if GNATprove_Mode then
SPARK_Specific.Generate_Dereference (N);
end if;
Analyze (P);
Set_Etype (N, Any_Type);
-- Test for remote access to subprogram type, and if so return
-- after rewriting the original tree.
if Remote_AST_E_Dereference (P) then
return;
end if;
-- Normal processing for other than remote access to subprogram type
if not Is_Overloaded (P) then
if Is_Access_Type (Etype (P)) then
-- Set the Etype
declare
DT : constant Entity_Id := Designated_Type (Etype (P));
begin
-- An explicit dereference is a legal occurrence of an
-- incomplete type imported through a limited_with clause, if
-- the full view is visible, or if we are within an instance
-- body, where the enclosing body has a regular with_clause
-- on the unit.
if From_Limited_With (DT)
and then not From_Limited_With (Scope (DT))
and then
(Is_Immediately_Visible (Scope (DT))
or else
(Is_Child_Unit (Scope (DT))
and then Is_Visible_Lib_Unit (Scope (DT)))
or else In_Instance_Body)
then
Set_Etype (N, Available_View (DT));
else
Set_Etype (N, DT);
end if;
end;
elsif Etype (P) /= Any_Type then
Error_Msg_N ("prefix of dereference must be an access type", N);
return;
end if;
else
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
T := It.Typ;
if Is_Access_Type (T) then
Add_One_Interp (N, Designated_Type (T), Designated_Type (T));
end if;
Get_Next_Interp (I, It);
end loop;
-- Error if no interpretation of the prefix has an access type
if Etype (N) = Any_Type then
Error_Msg_N
("access type required in prefix of explicit dereference", P);
Set_Etype (N, Any_Type);
return;
end if;
end if;
if Is_Function_Type
and then Nkind (Parent (N)) /= N_Indexed_Component
and then (Nkind (Parent (N)) /= N_Function_Call
or else N /= Name (Parent (N)))
and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement
or else N /= Name (Parent (N)))
and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration
and then (Nkind (Parent (N)) /= N_Attribute_Reference
or else
(Attribute_Name (Parent (N)) /= Name_Address
and then
Attribute_Name (Parent (N)) /= Name_Access))
then
-- Name is a function call with no actuals, in a context that
-- requires deproceduring (including as an actual in an enclosing
-- function or procedure call). There are some pathological cases
-- where the prefix might include functions that return access to
-- subprograms and others that return a regular type. Disambiguation
-- of those has to take place in Resolve.
New_N :=
Make_Function_Call (Loc,
Name => Make_Explicit_Dereference (Loc, P),
Parameter_Associations => New_List);
-- If the prefix is overloaded, remove operations that have formals,
-- we know that this is a parameterless call.
if Is_Overloaded (P) then
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
T := It.Typ;
if No (First_Formal (Base_Type (Designated_Type (T)))) then
Set_Etype (P, T);
else
Remove_Interp (I);
end if;
Get_Next_Interp (I, It);
end loop;
end if;
Rewrite (N, New_N);
Analyze (N);
elsif not Is_Function_Type
and then Is_Overloaded (N)
then
-- The prefix may include access to subprograms and other access
-- types. If the context selects the interpretation that is a
-- function call (not a procedure call) we cannot rewrite the node
-- yet, but we include the result of the call interpretation.
Get_First_Interp (N, I, It);
while Present (It.Nam) loop
if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type
and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type
and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
then
Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ));
end if;
Get_Next_Interp (I, It);
end loop;
end if;
-- A value of remote access-to-class-wide must not be dereferenced
-- (RM E.2.2(16)).
Validate_Remote_Access_To_Class_Wide_Type (N);
end Analyze_Explicit_Dereference;
------------------------
-- Analyze_Expression --
------------------------
procedure Analyze_Expression (N : Node_Id) is
begin
-- If the expression is an indexed component that will be rewritten
-- as a container indexing, it has already been analyzed.
if Nkind (N) = N_Indexed_Component
and then Present (Generalized_Indexing (N))
then
null;
else
Analyze (N);
Check_Parameterless_Call (N);
end if;
end Analyze_Expression;
-------------------------------------
-- Analyze_Expression_With_Actions --
-------------------------------------
procedure Analyze_Expression_With_Actions (N : Node_Id) is
procedure Check_Action_OK (A : Node_Id);
-- Check that the action A is allowed as a declare_item of a declare
-- expression if N and A come from source.
---------------------
-- Check_Action_OK --
---------------------
procedure Check_Action_OK (A : Node_Id) is
begin
if not Comes_From_Source (N) or else not Comes_From_Source (A) then
return; -- Allow anything in generated code
end if;
case Nkind (A) is
when N_Object_Declaration =>
if Nkind (Object_Definition (A)) = N_Access_Definition then
Error_Msg_N
("anonymous access type not allowed in declare_expression",
Object_Definition (A));
end if;
if Aliased_Present (A) then
Error_Msg_N ("ALIASED not allowed in declare_expression", A);
end if;
if Constant_Present (A)
and then not Is_Limited_Type (Etype (Defining_Identifier (A)))
then
return; -- nonlimited constants are OK
end if;
when N_Object_Renaming_Declaration =>
if Present (Access_Definition (A)) then
Error_Msg_N
("anonymous access type not allowed in declare_expression",
Access_Definition (A));
end if;
if not Is_Limited_Type (Etype (Defining_Identifier (A))) then
return; -- ???For now; the RM rule is a bit more complicated
end if;
when others =>
null; -- Nothing else allowed, not even pragmas
end case;
Error_Msg_N ("object renaming or constant declaration expected", A);
end Check_Action_OK;
A : Node_Id;
EWA_Scop : Entity_Id;
-- Start of processing for Analyze_Expression_With_Actions
begin
-- Create a scope, which is needed to provide proper visibility of the
-- declare_items.
EWA_Scop := New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B');
Set_Etype (EWA_Scop, Standard_Void_Type);
Set_Scope (EWA_Scop, Current_Scope);
Set_Parent (EWA_Scop, N);
Push_Scope (EWA_Scop);
-- If this Expression_With_Actions node comes from source, then it
-- represents a declare_expression; increment the counter to take note
-- of that.
if Comes_From_Source (N) then
In_Declare_Expr := In_Declare_Expr + 1;
end if;
A := First (Actions (N));
while Present (A) loop
Analyze (A);
Check_Action_OK (A);
Next (A);
end loop;
Analyze_Expression (Expression (N));
Set_Etype (N, Etype (Expression (N)));
End_Scope;
if Comes_From_Source (N) then
In_Declare_Expr := In_Declare_Expr - 1;
end if;
end Analyze_Expression_With_Actions;
---------------------------
-- Analyze_If_Expression --
---------------------------
procedure Analyze_If_Expression (N : Node_Id) is
Condition : constant Node_Id := First (Expressions (N));
Then_Expr : Node_Id;
Else_Expr : Node_Id;
begin
-- Defend against error of missing expressions from previous error
if No (Condition) then
Check_Error_Detected;
return;
end if;
Then_Expr := Next (Condition);
if No (Then_Expr) then
Check_Error_Detected;
return;
end if;
Else_Expr := Next (Then_Expr);
if Comes_From_Source (N) then
Check_Compiler_Unit ("if expression", N);
end if;
-- Analyze and resolve the condition. We need to resolve this now so
-- that it gets folded to True/False if possible, before we analyze
-- the THEN/ELSE branches, because when analyzing these branches, we
-- may call Is_Statically_Unevaluated, which expects the condition of
-- an enclosing IF to have been analyze/resolved/evaluated.
Analyze_Expression (Condition);
Resolve (Condition, Any_Boolean);
-- Analyze THEN expression and (if present) ELSE expression. For those
-- we delay resolution in the normal manner, because of overloading etc.
Analyze_Expression (Then_Expr);
if Present (Else_Expr) then
Analyze_Expression (Else_Expr);
end if;
-- If then expression not overloaded, then that decides the type
if not Is_Overloaded (Then_Expr) then
Set_Etype (N, Etype (Then_Expr));
-- Case where then expression is overloaded
else
declare
I : Interp_Index;
It : Interp;
begin
Set_Etype (N, Any_Type);
-- Loop through interpretations of Then_Expr
Get_First_Interp (Then_Expr, I, It);
while Present (It.Nam) loop
-- Add possible interpretation of Then_Expr if no Else_Expr, or
-- Else_Expr is present and has a compatible type.
if No (Else_Expr)
or else Has_Compatible_Type (Else_Expr, It.Typ)
then
Add_One_Interp (N, It.Typ, It.Typ);
end if;
Get_Next_Interp (I, It);
end loop;
-- If no valid interpretation has been found, then the type of the
-- ELSE expression does not match any interpretation of the THEN
-- expression.
if Etype (N) = Any_Type then
Error_Msg_N
("type incompatible with that of THEN expression",
Else_Expr);
return;
end if;
end;
end if;
end Analyze_If_Expression;
------------------------------------
-- Analyze_Indexed_Component_Form --
------------------------------------
procedure Analyze_Indexed_Component_Form (N : Node_Id) is
P : constant Node_Id := Prefix (N);
Exprs : constant List_Id := Expressions (N);
Exp : Node_Id;
P_T : Entity_Id;
E : Node_Id;
U_N : Entity_Id;
procedure Process_Function_Call;
-- Prefix in indexed component form is an overloadable entity, so the
-- node is very likely a function call; reformat it as such. The only
-- exception is a call to a parameterless function that returns an
-- array type, or an access type thereof, in which case this will be
-- undone later by Resolve_Call or Resolve_Entry_Call.
procedure Process_Indexed_Component;
-- Prefix in indexed component form is actually an indexed component.
-- This routine processes it, knowing that the prefix is already
-- resolved.
procedure Process_Indexed_Component_Or_Slice;
-- An indexed component with a single index may designate a slice if
-- the index is a subtype mark. This routine disambiguates these two
-- cases by resolving the prefix to see if it is a subtype mark.
procedure Process_Overloaded_Indexed_Component;
-- If the prefix of an indexed component is overloaded, the proper
-- interpretation is selected by the index types and the context.
---------------------------
-- Process_Function_Call --
---------------------------
procedure Process_Function_Call is
Loc : constant Source_Ptr := Sloc (N);
Actual : Node_Id;
begin
Change_Node (N, N_Function_Call);
Set_Name (N, P);
Set_Parameter_Associations (N, Exprs);
-- Analyze actuals prior to analyzing the call itself
Actual := First (Parameter_Associations (N));
while Present (Actual) loop
Analyze (Actual);
Check_Parameterless_Call (Actual);
-- Move to next actual. Note that we use Next, not Next_Actual
-- here. The reason for this is a bit subtle. If a function call
-- includes named associations, the parser recognizes the node
-- as a call, and it is analyzed as such. If all associations are
-- positional, the parser builds an indexed_component node, and
-- it is only after analysis of the prefix that the construct
-- is recognized as a call, in which case Process_Function_Call
-- rewrites the node and analyzes the actuals. If the list of
-- actuals is malformed, the parser may leave the node as an
-- indexed component (despite the presence of named associations).
-- The iterator Next_Actual is equivalent to Next if the list is
-- positional, but follows the normalized chain of actuals when
-- named associations are present. In this case normalization has
-- not taken place, and actuals remain unanalyzed, which leads to
-- subsequent crashes or loops if there is an attempt to continue
-- analysis of the program.
-- IF there is a single actual and it is a type name, the node
-- can only be interpreted as a slice of a parameterless call.
-- Rebuild the node as such and analyze.
if No (Next (Actual))
and then Is_Entity_Name (Actual)
and then Is_Type (Entity (Actual))
and then Is_Discrete_Type (Entity (Actual))
and then not Is_Current_Instance (Actual)
then
Replace (N,
Make_Slice (Loc,
Prefix => P,
Discrete_Range =>
New_Occurrence_Of (Entity (Actual), Loc)));
Analyze (N);
return;
else
Next (Actual);
end if;
end loop;
Analyze_Call (N);
end Process_Function_Call;
-------------------------------
-- Process_Indexed_Component --
-------------------------------
procedure Process_Indexed_Component is
Exp : Node_Id;
Array_Type : Entity_Id;
Index : Node_Id;
Pent : Entity_Id := Empty;
begin
Exp := First (Exprs);
if Is_Overloaded (P) then
Process_Overloaded_Indexed_Component;
else
Array_Type := Etype (P);
if Is_Entity_Name (P) then
Pent := Entity (P);
elsif Nkind (P) = N_Selected_Component
and then Is_Entity_Name (Selector_Name (P))
then
Pent := Entity (Selector_Name (P));
end if;
-- Prefix must be appropriate for an array type, taking into
-- account a possible implicit dereference.
if Is_Access_Type (Array_Type) then
Error_Msg_NW
(Warn_On_Dereference, "?d?implicit dereference", N);
Array_Type := Implicitly_Designated_Type (Array_Type);
end if;
if Is_Array_Type (Array_Type) then
-- In order to correctly access First_Index component later,
-- replace string literal subtype by its parent type.
if Ekind (Array_Type) = E_String_Literal_Subtype then
Array_Type := Etype (Array_Type);
end if;
elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then
Analyze (Exp);
Set_Etype (N, Any_Type);
if not Has_Compatible_Type (Exp, Entry_Index_Type (Pent)) then
Error_Msg_N ("invalid index type in entry name", N);
elsif Present (Next (Exp)) then
Error_Msg_N ("too many subscripts in entry reference", N);
else
Set_Etype (N, Etype (P));
end if;
return;
elsif Is_Record_Type (Array_Type)
and then Remote_AST_I_Dereference (P)
then
return;
elsif Try_Container_Indexing (N, P, Exprs) then
return;
elsif Array_Type = Any_Type then
Set_Etype (N, Any_Type);
-- In most cases the analysis of the prefix will have emitted
-- an error already, but if the prefix may be interpreted as a
-- call in prefixed notation, the report is left to the caller.
-- To prevent cascaded errors, report only if no previous ones.
if Serious_Errors_Detected = 0 then
Error_Msg_N ("invalid prefix in indexed component", P);
if Nkind (P) = N_Expanded_Name then
Error_Msg_NE ("\& is not visible", P, Selector_Name (P));
end if;
end if;
return;
-- Here we definitely have a bad indexing
else
if Nkind (Parent (N)) = N_Requeue_Statement
and then Present (Pent) and then Ekind (Pent) = E_Entry
then
Error_Msg_N
("REQUEUE does not permit parameters", First (Exprs));
elsif Is_Entity_Name (P)
and then Etype (P) = Standard_Void_Type
then
Error_Msg_NE ("incorrect use of &", P, Entity (P));
else
Error_Msg_N ("array type required in indexed component", P);
end if;
Set_Etype (N, Any_Type);
return;
end if;
Index := First_Index (Array_Type);
while Present (Index) and then Present (Exp) loop
if not Has_Compatible_Type (Exp, Etype (Index)) then
Wrong_Type (Exp, Etype (Index));
Set_Etype (N, Any_Type);
return;
end if;
Next_Index (Index);
Next (Exp);
end loop;
Set_Etype (N, Component_Type (Array_Type));
Check_Implicit_Dereference (N, Etype (N));
if Present (Index) then
Error_Msg_N
("too few subscripts in array reference", First (Exprs));
elsif Present (Exp) then
Error_Msg_N ("too many subscripts in array reference", Exp);
end if;
end if;
end Process_Indexed_Component;
----------------------------------------
-- Process_Indexed_Component_Or_Slice --
----------------------------------------
procedure Process_Indexed_Component_Or_Slice is
begin
Exp := First (Exprs);
while Present (Exp) loop
Analyze_Expression (Exp);
Next (Exp);
end loop;
Exp := First (Exprs);
-- If one index is present, and it is a subtype name, then the node
-- denotes a slice (note that the case of an explicit range for a
-- slice was already built as an N_Slice node in the first place,
-- so that case is not handled here).
-- We use a replace rather than a rewrite here because this is one
-- of the cases in which the tree built by the parser is plain wrong.
if No (Next (Exp))
and then Is_Entity_Name (Exp)
and then Is_Type (Entity (Exp))
then
Replace (N,
Make_Slice (Sloc (N),
Prefix => P,
Discrete_Range => New_Copy (Exp)));
Analyze (N);
-- Otherwise (more than one index present, or single index is not
-- a subtype name), then we have the indexed component case.
else
Process_Indexed_Component;
end if;
end Process_Indexed_Component_Or_Slice;
------------------------------------------
-- Process_Overloaded_Indexed_Component --
------------------------------------------
procedure Process_Overloaded_Indexed_Component is
Exp : Node_Id;
I : Interp_Index;
It : Interp;
Typ : Entity_Id;
Index : Node_Id;
Found : Boolean;
begin
Set_Etype (N, Any_Type);
Get_First_Interp (P, I, It);
while Present (It.Nam) loop
Typ := It.Typ;
if Is_Access_Type (Typ) then
Typ := Designated_Type (Typ);
Error_Msg_NW
(Warn_On_Dereference, "?d?implicit dereference", N);
end if;
if Is_Array_Type (Typ) then
-- Got a candidate: verify that index types are compatible
Index := First_Index (Typ);
Found := True;
Exp := First (Exprs);
while Present (Index) and then Present (Exp) loop
if Has_Compatible_Type (Exp, Etype (Index)) then
null;
else
Found := False;
Remove_Interp (I);
exit;
end if;
Next_Index (Index);
Next (Exp);
end loop;
if Found and then No (Index) and then No (Exp) then
declare
CT : constant Entity_Id :=
Base_Type (Component_Type (Typ));
begin
Add_One_Interp (N, CT, CT);
Check_Implicit_Dereference (N, CT);
end;
end if;
elsif Try_Container_Indexing (N, P, Exprs) then
return;
end if;
Get_Next_Interp (I, It);
end loop;
if Etype (N) = Any_Type then
Error_Msg_N ("no legal interpretation for indexed component", N);
Set_Is_Overloaded (N, False);
end if;
end Process_Overloaded_Indexed_Component;
-- Start of processing for Analyze_Indexed_Component_Form
begin
-- Get name of array, function or type
Analyze (P);
-- If P is an explicit dereference whose prefix is of a remote access-
-- to-subprogram type, then N has already been rewritten as a subprogram
-- call and analyzed.
if Nkind (N) in N_Subprogram_Call then
return;
-- When the prefix is attribute 'Loop_Entry and the sole expression of
-- the indexed component denotes a loop name, the indexed form is turned
-- into an attribute reference.
elsif Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) = Name_Loop_Entry
then
return;
end if;
pragma Assert (Nkind (N) = N_Indexed_Component);
P_T := Base_Type (Etype (P));
if Is_Entity_Name (P) and then Present (Entity (P)) then
U_N := Entity (P);
if Is_Type (U_N) then
-- Reformat node as a type conversion
E := Remove_Head (Exprs);
if Present (First (Exprs)) then
Error_Msg_N
("argument of type conversion must be single expression", N);
end if;
Change_Node (N, N_Type_Conversion);
Set_Subtype_Mark (N, P);
Set_Etype (N, U_N);
Set_Expression (N, E);
-- After changing the node, call for the specific Analysis
-- routine directly, to avoid a double call to the expander.
Analyze_Type_Conversion (N);
return;
end if;
if Is_Overloadable (U_N) then
Process_Function_Call;
elsif Ekind (Etype (P)) = E_Subprogram_Type
or else (Is_Access_Type (Etype (P))
and then
Ekind (Designated_Type (Etype (P))) =
E_Subprogram_Type)
then
-- Call to access_to-subprogram with possible implicit dereference
Process_Function_Call;
elsif Is_Generic_Subprogram (U_N) then
-- A common beginner's (or C++ templates fan) error
Error_Msg_N ("generic subprogram cannot be called", N);
Set_Etype (N, Any_Type);
return;
else
Process_Indexed_Component_Or_Slice;
end if;
-- If not an entity name, prefix is an expression that may denote
-- an array or an access-to-subprogram.
else
if Ekind (P_T) = E_Subprogram_Type
or else (Is_Access_Type (P_T)
and then
Ekind (Designated_Type (P_T)) = E_Subprogram_Type)
then
Process_Function_Call;
elsif Nkind (P) = N_Selected_Component
and then Present (Entity (Selector_Name (P)))
and then Is_Overloadable (Entity (Selector_Name (P)))
then
Process_Function_Call;
else
-- Indexed component, slice, or a call to a member of a family
-- entry, which will be converted to an entry call later.
Process_Indexed_Component_Or_Slice;
end if;
end if;
Analyze_Dimension (N);
end Analyze_Indexed_Component_Form;
------------------------
-- Analyze_Logical_Op --
------------------------
procedure Analyze_Logical_Op (N : Node_Id) is
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (L);
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Boolean_Types (L, R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Boolean_Types (L, R, Op_Id, N);
else
Analyze_User_Defined_Binary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
Check_Function_Writable_Actuals (N);
end Analyze_Logical_Op;
---------------------------
-- Analyze_Membership_Op --
---------------------------
procedure Analyze_Membership_Op (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
L : constant Node_Id := Left_Opnd (N);
R : constant Node_Id := Right_Opnd (N);
Index : Interp_Index;
It : Interp;
Found : Boolean := False;
I_F : Interp_Index;
T_F : Entity_Id;
procedure Analyze_Set_Membership;
-- If a set of alternatives is present, analyze each and find the
-- common type to which they must all resolve.
procedure Find_Interpretation;
function Find_Interpretation return Boolean;
-- Routine and wrapper to find a matching interpretation in case
-- of overloading. The wrapper returns True iff a matching
-- interpretation is found. Beware, in absence of overloading,
-- using this function will break gnat's bootstrapping.
procedure Try_One_Interp (T1 : Entity_Id);
-- Routine to try one proposed interpretation. Note that the context
-- of the operation plays no role in resolving the arguments, so that
-- if there is more than one interpretation of the operands that is
-- compatible with a membership test, the operation is ambiguous.
----------------------------
-- Analyze_Set_Membership --
----------------------------
procedure Analyze_Set_Membership is
Alt : Node_Id;
Index : Interp_Index;
It : Interp;
Candidate_Interps : Node_Id;
Common_Type : Entity_Id := Empty;
begin
if Comes_From_Source (N) then
Check_Compiler_Unit ("set membership", N);
end if;
Analyze (L);
Candidate_Interps := L;
if not Is_Overloaded (L) then
Common_Type := Etype (L);
Alt := First (Alternatives (N));
while Present (Alt) loop
Analyze (Alt);
if not Has_Compatible_Type (Alt, Common_Type) then
Wrong_Type (Alt, Common_Type);
end if;
Next (Alt);
end loop;
else
Alt := First (Alternatives (N));
while Present (Alt) loop
Analyze (Alt);
if not Is_Overloaded (Alt) then
Common_Type := Etype (Alt);
else
Get_First_Interp (Alt, Index, It);
while Present (It.Typ) loop
if not
Has_Compatible_Type (Candidate_Interps, It.Typ)
then
Remove_Interp (Index);
end if;
Get_Next_Interp (Index, It);
end loop;
Get_First_Interp (Alt, Index, It);
if No (It.Typ) then
Error_Msg_N ("alternative has no legal type", Alt);
return;
end if;
-- If alternative is not overloaded, we have a unique type
-- for all of them.
Set_Etype (Alt, It.Typ);
-- If the alternative is an enumeration literal, use the one
-- for this interpretation.
if Is_Entity_Name (Alt) then
Set_Entity (Alt, It.Nam);
end if;
Get_Next_Interp (Index, It);
if No (It.Typ) then
Set_Is_Overloaded (Alt, False);
Common_Type := Etype (Alt);
end if;
Candidate_Interps := Alt;
end if;
Next (Alt);
end loop;
end if;
Set_Etype (N, Standard_Boolean);
if Present (Common_Type) then
Set_Etype (L, Common_Type);
-- The left operand may still be overloaded, to be resolved using
-- the Common_Type.
else
Error_Msg_N ("cannot resolve membership operation", N);
end if;
end Analyze_Set_Membership;
-------------------------
-- Find_Interpretation --
-------------------------
procedure Find_Interpretation is
begin
Get_First_Interp (L, Index, It);
while Present (It.Typ) loop
Try_One_Interp (It.Typ);
Get_Next_Interp (Index, It);
end loop;
end Find_Interpretation;
function Find_Interpretation return Boolean is
begin
Find_Interpretation;
return Found;
end Find_Interpretation;
--------------------
-- Try_One_Interp --
--------------------
procedure Try_One_Interp (T1 : Entity_Id) is
begin
if Has_Compatible_Type (R, T1) then
if Found
and then Base_Type (T1) /= Base_Type (T_F)
then
It := Disambiguate (L, I_F, Index, Any_Type);
if It = No_Interp then
Ambiguous_Operands (N);
Set_Etype (L, Any_Type);
return;
else
T_F := It.Typ;
end if;
else
Found := True;
T_F := T1;
I_F := Index;
end if;
Set_Etype (L, T_F);
end if;
end Try_One_Interp;
Op : Node_Id;
-- Start of processing for Analyze_Membership_Op
begin
Analyze_Expression (L);
if No (R) then
pragma Assert (Ada_Version >= Ada_2012);
Analyze_Set_Membership;
Check_Function_Writable_Actuals (N);
return;
end if;
if Nkind (R) = N_Range
or else (Nkind (R) = N_Attribute_Reference
and then Attribute_Name (R) = Name_Range)
then
Analyze (R);
if not Is_Overloaded (L) then
Try_One_Interp (Etype (L));
else
Find_Interpretation;
end if;
-- If not a range, it can be a subtype mark, or else it is a degenerate
-- membership test with a singleton value, i.e. a test for equality,
-- if the types are compatible.
else
Analyze (R);
if Is_Entity_Name (R)
and then Is_Type (Entity (R))
then
Find_Type (R);
Check_Fully_Declared (Entity (R), R);
elsif Ada_Version >= Ada_2012 and then
((Is_Overloaded (L) and then Find_Interpretation) or else
(not Is_Overloaded (L) and then Has_Compatible_Type (R, Etype (L))))
then
if Nkind (N) = N_In then
Op := Make_Op_Eq (Loc, Left_Opnd => L, Right_Opnd => R);
else
Op := Make_Op_Ne (Loc, Left_Opnd => L, Right_Opnd => R);
end if;
if Is_Record_Or_Limited_Type (Etype (L)) then
-- We reset the Entity in order to use the primitive equality
-- of the type, as per RM 4.5.2 (28.1/4).
Set_Entity (Op, Empty);
end if;
Rewrite (N, Op);
Analyze (N);
return;
else
-- In all versions of the language, if we reach this point there
-- is a previous error that will be diagnosed below.
Find_Type (R);
end if;
end if;
-- Compatibility between expression and subtype mark or range is
-- checked during resolution. The result of the operation is Boolean
-- in any case.
Set_Etype (N, Standard_Boolean);
if Comes_From_Source (N)
and then Present (Right_Opnd (N))
and then Is_CPP_Class (Etype (Etype (Right_Opnd (N))))
then
Error_Msg_N ("membership test not applicable to cpp-class types", N);
end if;
Check_Function_Writable_Actuals (N);
end Analyze_Membership_Op;
-----------------
-- Analyze_Mod --
-----------------
procedure Analyze_Mod (N : Node_Id) is
begin
-- A special warning check, if we have an expression of the form:
-- expr mod 2 * literal
-- where literal is 128 or less, then probably what was meant was
-- expr mod 2 ** literal
-- so issue an appropriate warning.
if Warn_On_Suspicious_Modulus_Value
and then Nkind (Right_Opnd (N)) = N_Integer_Literal
and then Intval (Right_Opnd (N)) = Uint_2
and then Nkind (Parent (N)) = N_Op_Multiply
and then Nkind (Right_Opnd (Parent (N))) = N_Integer_Literal
and then Intval (Right_Opnd (Parent (N))) <= Uint_128
then
Error_Msg_N
("suspicious MOD value, was '*'* intended'??.m?", Parent (N));
end if;
-- Remaining processing is same as for other arithmetic operators
Analyze_Arithmetic_Op (N);
end Analyze_Mod;
----------------------
-- Analyze_Negation --
----------------------
procedure Analyze_Negation (N : Node_Id) is
R : constant Node_Id := Right_Opnd (N);
Op_Id : Entity_Id := Entity (N);
begin
Set_Etype (N, Any_Type);
Candidate_Type := Empty;
Analyze_Expression (R);
if Present (Op_Id) then
if Ekind (Op_Id) = E_Operator then
Find_Negation_Types (R, Op_Id, N);
else
Add_One_Interp (N, Op_Id, Etype (Op_Id));
end if;
else
Op_Id := Get_Name_Entity_Id (Chars (N));
while Present (Op_Id) loop
if Ekind (Op_Id) = E_Operator then
Find_Negation_Types (R, Op_Id, N);
else
Analyze_User_Defined_Unary_Op (N, Op_Id);
end if;
Op_Id := Homonym (Op_Id);
end loop;
end if;
Operator_Check (N);
end Analyze_Negation;
------------------
-- Analyze_Null --
------------------
procedure Analyze_Null (N : Node_Id) is
begin
Set_Etype (N, Any_Access);
end Analyze_Null;
----------------------
-- Analyze_One_Call --
----------------------
procedure Analyze_One_Call
(N : Node_Id;
Nam : Entity_Id;
Report : Boolean;
Success : out Boolean;
Skip_First : Boolean := False)
is
Actuals : constant List_Id := Parameter_Associations (N);
Prev_T : constant Entity_Id := Etype (N);
-- Recognize cases of prefixed calls that have been rewritten in
-- various ways. The simplest case is a rewritten selected component,
-- but it can also be an already-examined indexed component, or a
-- prefix that is itself a rewritten prefixed call that is in turn
-- an indexed call (the syntactic ambiguity involving the indexing of
-- a function with defaulted parameters that returns an array).
-- A flag Maybe_Indexed_Call might be useful here ???
Must_Skip : constant Boolean := Skip_First
or else Nkind (Original_Node (N)) = N_Selected_Component
or else
(Nkind (Original_Node (N)) = N_Indexed_Component
and then Nkind (Prefix (Original_Node (N))) =
N_Selected_Component)
or else
(Nkind (Parent (N)) = N_Function_Call
and then Is_Array_Type (Etype (Name (N)))
and then Etype (Original_Node (N)) =
Component_Type (Etype (Name (N)))
and then Nkind (Original_Node (Parent (N))) =
N_Selected_Component);
-- The first formal must be omitted from the match when trying to find
-- a primitive operation that is a possible interpretation, and also
-- after the call has been rewritten, because the corresponding actual
-- is already known to be compatible, and because this may be an
-- indexing of a call with default parameters.
First_Form : Entity_Id;
Formal : Entity_Id;
Actual : Node_Id;
Is_Indexed : Boolean := False;
Is_Indirect : Boolean := False;
Subp_Type : constant Entity_Id := Etype (Nam);
Norm_OK : Boolean;
function Compatible_Types_In_Predicate
(T1 : Entity_Id;
T2 : Entity_Id) return Boolean;
-- For an Ada 2012 predicate or invariant, a call may mention an
-- incomplete type, while resolution of the corresponding predicate
-- function may see the full view, as a consequence of the delayed
-- resolution of the corresponding expressions. This may occur in
-- the body of a predicate function, or in a call to such. Anomalies
-- involving private and full views can also happen. In each case,
-- rewrite node or add conversions to remove spurious type errors.
procedure Indicate_Name_And_Type;
-- If candidate interpretation matches, indicate name and type of result
-- on call node.
function Operator_Hidden_By (Fun : Entity_Id) return Boolean;
-- There may be a user-defined operator that hides the current
-- interpretation. We must check for this independently of the
-- analysis of the call with the user-defined operation, because
-- the parameter names may be wrong and yet the hiding takes place.
-- This fixes a problem with ACATS test B34014O.
--
-- When the type Address is a visible integer type, and the DEC
-- system extension is visible, the predefined operator may be
-- hidden as well, by one of the address operations in auxdec.
-- Finally, the abstract operations on address do not hide the
-- predefined operator (this is the purpose of making them abstract).
-----------------------------------
-- Compatible_Types_In_Predicate --
-----------------------------------
function Compatible_Types_In_Predicate
(T1 : Entity_Id;
T2 : Entity_Id) return Boolean
is
function Common_Type (T : Entity_Id) return Entity_Id;
-- Find non-private underlying full view if any, without going to
-- ancestor type (as opposed to Underlying_Type).
-----------------
-- Common_Type --
-----------------
function Common_Type (T : Entity_Id) return Entity_Id is
CT : Entity_Id;
begin
CT := T;
if Is_Private_Type (CT) and then Present (Full_View (CT)) then
CT := Full_View (CT);
end if;
if Is_Private_Type (CT)
and then Present (Underlying_Full_View (CT))
then
CT := Underlying_Full_View (CT);
end if;
return Base_Type (CT);
end Common_Type;
-- Start of processing for Compatible_Types_In_Predicate
begin
if (Ekind (Current_Scope) = E_Function
and then Is_Predicate_Function (Current_Scope))
or else
(Ekind (Nam) = E_Function
and then Is_Predicate_Function (Nam))
then
if Is_Incomplete_Type (T1)
and then Present (Full_View (T1))
and then Full_View (T1) = T2
then
Set_Etype (Formal, Etype (Actual));
return True;
elsif Common_Type (T1) = Common_Type (T2) then
Rewrite (Actual, Unchecked_Convert_To (Etype (Formal), Actual));
return True;
else
return False;
end if;
else
return False;
end if;
end Compatible_Types_In_Predicate;
----------------------------
-- Indicate_Name_And_Type --
----------------------------
procedure Indicate_Name_And_Type is
begin
Add_One_Interp (N, Nam, Etype (Nam));
Check_Implicit_Dereference (N, Etype (Nam));
Success := True;
-- If the prefix of the call is a name, indicate the entity
-- being called. If it is not a name, it is an expression that
-- denotes an access to subprogram or else an entry or family. In
-- the latter case, the name is a selected component, and the entity
-- being called is noted on the selector.
if not Is_Type (Nam) then
if Is_Entity_Name (Name (N)) then
Set_Entity (Name (N), Nam);
Set_Etype (Name (N), Etype (Nam));
elsif Nkind (Name (N)) = N_Selected_Component then
Set_Entity (Selector_Name (Name (N)), Nam);
end if;
end if;
if Debug_Flag_E and not Report then
Write_Str (" Overloaded call ");
Write_Int (Int (N));
Write_Str (" compatible with ");
Write_Int (Int (Nam));
Write_Eol;
end if;
end Indicate_Name_And_Type;
------------------------
-- Operator_Hidden_By --
------------------------
function Operator_Hidden_By (Fun : Entity_Id) return Boolean is
Act1 : constant Node_Id := First_Actual (N);
Act2 : constant Node_Id := Next_Actual (Act1);
Form1 : constant Entity_Id := First_Formal (Fun);
Form2 : constant Entity_Id := Next_Formal (Form1);
begin
if Ekind (Fun) /= E_Function or else Is_Abstract_Subprogram (Fun) then
return False;
elsif not Has_Compatible_Type (Act1, Etype (Form1)) then
return False;
elsif Present (Form2) then
if No (Act2)
or else not Has_Compatible_Type (Act2, Etype (Form2))
then
return False;
end if;
elsif Present (Act2) then
return False;
end if;
-- Now we know that the arity of the operator matches the function,
-- and the function call is a valid interpretation. The function
-- hides the operator if it has the right signature, or if one of
-- its operands is a non-abstract operation on Address when this is
-- a visible integer type.
return Hides_Op (Fun, Nam)
or else Is_Descendant_Of_Address (Etype (Form1))
or else
(Present (Form2)
and then Is_Descendant_Of_Address (Etype (Form2)));
end Operator_Hidden_By;
-- Start of processing for Analyze_One_Call
begin
Success := False;
-- If the subprogram has no formals or if all the formals have defaults,
-- and the return type is an array type, the node may denote an indexing
-- of the result of a parameterless call. In Ada 2005, the subprogram
-- may have one non-defaulted formal, and the call may have been written
-- in prefix notation, so that the rebuilt parameter list has more than
-- one actual.
if not Is_Overloadable (Nam)
and then Ekind (Nam) /= E_Subprogram_Type
and then Ekind (Nam) /= E_Entry_Family
then
return;
end if;
-- An indexing requires at least one actual. The name of the call cannot
-- be an implicit indirect call, so it cannot be a generated explicit
-- dereference.
if not Is_Empty_List (Actuals)
and then
(Needs_No_Actuals (Nam)
or else
(Needs_One_Actual (Nam)
and then Present (Next_Actual (First (Actuals)))))
then
if Is_Array_Type (Subp_Type)
and then
(Nkind (Name (N)) /= N_Explicit_Dereference
or else Comes_From_Source (Name (N)))
then
Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip);
elsif Is_Access_Type (Subp_Type)
and then Is_Array_Type (Designated_Type (Subp_Type))
then
Is_Indexed :=
Try_Indexed_Call
(N, Nam, Designated_Type (Subp_Type), Must_Skip);
-- The prefix can also be a parameterless function that returns an
-- access to subprogram, in which case this is an indirect call.
-- If this succeeds, an explicit dereference is added later on,
-- in Analyze_Call or Resolve_Call.
elsif Is_Access_Type (Subp_Type)
and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type
then
Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type);
end if;
end if;
-- If the call has been transformed into a slice, it is of the form
-- F (Subtype) where F is parameterless. The node has been rewritten in
-- Try_Indexed_Call and there is nothing else to do.
if Is_Indexed
and then Nkind (N) = N_Slice
then
return;
end if;
Normalize_Actuals
(N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK);
if not Norm_OK then
-- If an indirect call is a possible interpretation, indicate
-- success to the caller. This may be an indexing of an explicit
-- dereference of a call that returns an access type (see above).
if Is_Indirect
or else (Is_Indexed
and then Nkind (Name (N)) = N_Explicit_Dereference
and then Comes_From_Source (Name (N)))
then
Success := True;
return;
-- Mismatch in number or names of parameters
elsif Debug_Flag_E then
Write_Str (" normalization fails in call ");
Write_Int (Int (N));
Write_Str (" with subprogram ");
Write_Int (Int (Nam));
Write_Eol;
end if;
-- If the context expects a function call, discard any interpretation
-- that is a procedure. If the node is not overloaded, leave as is for
-- better error reporting when type mismatch is found.
elsif Nkind (N) = N_Function_Call
and then Is_Overloaded (Name (N))
and then Ekind (Nam) = E_Procedure
then
return;
-- Ditto for function calls in a procedure context
elsif Nkind (N) = N_Procedure_Call_Statement
and then Is_Overloaded (Name (N))
and then Etype (Nam) /= Standard_Void_Type
then
return;
elsif No (Actuals) then
-- If Normalize succeeds, then there are default parameters for
-- all formals.
Indicate_Name_And_Type;
elsif Ekind (Nam) = E_Operator then
if Nkind (N) = N_Procedure_Call_Statement then
return;
end if;
-- This can occur when the prefix of the call is an operator
-- name or an expanded name whose selector is an operator name.
Analyze_Operator_Call (N, Nam);
if Etype (N) /= Prev_T then
-- Check that operator is not hidden by a function interpretation
if Is_Overloaded (Name (N)) then
declare
I : Interp_Index;
It : Interp;
begin
Get_First_Interp (Name (N), I, It);
while Present (It.Nam) loop
if Operator_Hidden_By (It.Nam) then
Set_Etype (N, Prev_T);
return;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
-- If operator matches formals, record its name on the call.
-- If the operator is overloaded, Resolve will select the
-- correct one from the list of interpretations. The call
-- node itself carries the first candidate.
Set_Entity (Name (N), Nam);
Success := True;
elsif Report and then Etype (N) = Any_Type then
Error_Msg_N ("incompatible arguments for operator", N);
end if;
else
-- Normalize_Actuals has chained the named associations in the
-- correct order of the formals.
Actual := First_Actual (N);
Formal := First_Formal (Nam);
First_Form := Formal;
-- If we are analyzing a call rewritten from object notation, skip
-- first actual, which may be rewritten later as an explicit
-- dereference.
if Must_Skip then
Next_Actual (Actual);
Next_Formal (Formal);
end if;
while Present (Actual) and then Present (Formal) loop
if Nkind (Parent (Actual)) /= N_Parameter_Association
or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal)
then
-- The actual can be compatible with the formal, but we must
-- also check that the context is not an address type that is