blob: 4e97b7ac2504c2458f3dc3f63f5baeac6505a9e7 [file] [log] [blame]
-- --
-- --
-- S E M _ R E S --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2022, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- 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. --
-- --
-- Resolution processing for all subexpression nodes. Note that the separate
-- package Sem_Aggr contains the actual resolution routines for aggregates,
-- which are separated off since aggregate processing is complex.
with Types; use Types;
package Sem_Res is
-- As described in Sem_Type, the type resolution proceeds in two phases.
-- The first phase is a bottom up pass that is achieved during the
-- recursive traversal performed by the Analyze procedures. This phase
-- determines unambiguous types, and collects sets of possible types
-- where the interpretation is potentially ambiguous.
-- On completing this bottom up pass, which corresponds to a call to
-- Analyze on a complete context, the Resolve routine is called which
-- performs a top down resolution with recursive calls to itself to
-- resolve operands.
-- Since in practice a lot of semantic analysis has to be postponed until
-- types are known (e.g. static folding, setting of suppress flags), the
-- Resolve routines also complete the semantic analysis, and call the
-- expander for possible expansion of the completely type resolved node.
procedure Ambiguous_Character (C : Node_Id);
-- Give list of candidate interpretations when a character literal cannot
-- be resolved, for example in a (useless) comparison such as 'A' = 'B'.
-- In Ada 95 the literals in question can be of type Character or Wide_
-- Character. In Ada 2005 Wide_Wide_Character is also a candidate. The
-- node may also be overloaded with user-defined character types.
procedure Analyze_And_Resolve (N : Node_Id);
procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id);
procedure Analyze_And_Resolve
(N : Node_Id;
Typ : Entity_Id;
Suppress : Check_Id);
procedure Analyze_And_Resolve
(N : Node_Id;
Suppress : Check_Id);
-- These routines combine the effect of Analyze and Resolve. If a Suppress
-- argument is present, then the analysis is done with the specified check
-- suppressed (can be All_Checks to suppress all checks). These checks are
-- suppressed for both the analysis and resolution. If the type argument
-- is not present, then the Etype of the expression after the Analyze
-- call is used for the Resolve.
procedure Check_Parameterless_Call (N : Node_Id);
-- Several forms of names can denote calls to entities without parameters.
-- The context determines whether the name denotes the entity or a call to
-- it. When it is a call, the node must be rebuilt accordingly and
-- reanalyzed to obtain possible interpretations.
-- The name may be that of an overloadable construct, or it can be an
-- explicit dereference of a prefix that denotes an access to subprogram.
-- In that case, we want to convert the name into a call only if the
-- context requires the return type of the subprogram. Finally, a
-- parameterless protected subprogram appears as a selected component.
-- The parameter T is the Typ for the corresponding resolve call.
procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id);
-- Performs a preanalysis of expression node N. During preanalysis, N is
-- analyzed and then resolved against type T, but no expansion is carried
-- out for N or its children. For more info on preanalysis read the spec
-- of Sem.
procedure Preanalyze_And_Resolve (N : Node_Id);
-- Same, but use type of node because context does not impose a single type
procedure Preanalyze_With_Freezing_And_Resolve (N : Node_Id; T : Entity_Id);
-- Same, but perform freezing of static expressions of N or its children.
procedure Resolve (N : Node_Id; Typ : Entity_Id);
procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id);
-- Top-level type-checking procedure, called in a complete context. The
-- construct N, which is a subexpression, has already been analyzed, and
-- is required to be of type Typ given the analysis of the context (which
-- uses the information gathered on the bottom-up phase in Analyze). The
-- resolve routines do various other processing, e.g. static evaluation.
-- If a Suppress argument is present, then the resolution is done with the
-- specified check suppressed (can be All_Checks to suppress all checks).
procedure Resolve (N : Node_Id);
-- A version of Resolve where the type to be used for resolution is taken
-- from the Etype (N). This is commonly used in cases where the context
-- does not add anything and the first pass of analysis found the correct
-- expected type.
procedure Resolve_Discrete_Subtype_Indication
(N : Node_Id;
Typ : Entity_Id);
-- Resolve subtype indications in choices (case statements and aggregates)
-- and in index constraints. Note that the resulting Etype of the subtype_
-- indication node is set to the Etype of the contained range (i.e. an
-- Itype is not constructed for the actual subtype).
procedure Resolve_Entry (Entry_Name : Node_Id);
-- Find name of entry being called, and resolve prefix of name with its
-- own type. For now we assume that the prefix cannot be overloaded and
-- the name of the entry plays no role in the resolution.
procedure Resolve_Membership_Equality (N : Node_Id; Typ : Entity_Id);
-- Resolve the equality operator in an individual membership test
function Valid_Conversion
(N : Node_Id;
Target : Entity_Id;
Operand : Node_Id;
Report_Errs : Boolean := True) return Boolean;
-- Verify legality rules given in 4.6 (8-23). Target is the target type
-- of the conversion, which may be an implicit conversion of an actual
-- parameter to an anonymous access type (in which case N denotes the
-- actual parameter and N = Operand). Returns a Boolean result indicating
-- whether the conversion is legal. Reports errors in the case of illegal
-- conversions, unless Report_Errs is False.
procedure Resolve_Implicit_Type (N : Node_Id) renames Resolve;
pragma Inline (Resolve_Implicit_Type);
-- We use this renaming to make the application of Inline very explicit to
-- this version, since other versions of Resolve are not inlined.
end Sem_Res;