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3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-1999 Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
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29 -- Resolution processing for all subexpression nodes. Note that the separate
30 -- package Sem_Aggr contains the actual resolution routines for aggregates,
31 -- which are separated off since aggregate processing is complex.
33 with Snames; use Snames;
34 with Types; use Types;
38 -- As described in Sem_Ch4, the type resolution proceeds in two phases.
39 -- The first phase is a bottom up pass that is achieved during the
40 -- recursive traversal performed by the Analyze procedures. This phase
41 -- determines unambiguous types, and collects sets of possible types
42 -- where the interpretation is potentially ambiguous.
44 -- On completing this bottom up pass, which corresponds to a call to
45 -- Analyze on a complete context, the Resolve routine is called which
46 -- performs a top down resolution with recursive calls to itself to
49 -- Since in practice a lot of semantic analysis has to be postponed until
50 -- types are known (e.g. static folding, setting of suppress flags), the
51 -- Resolve routines also complete the semantic analyze, and also call the
52 -- expander for possibly expansion of the completely type resolved node.
54 procedure Resolve (N : Node_Id; Typ : Entity_Id);
55 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id);
56 -- Top level type-checking procedure, called in a complete context. The
57 -- construct N, which is a subexpression, has already been analyzed, and
58 -- is required to be of type Typ given the analysis of the context (which
59 -- uses the information gathered on the bottom up phase in Analyze). The
60 -- resolve routines do various other processing, e.g. static evaluation.
61 -- If a Suppress argument is present, then the resolution is done with the
62 -- specified check suppressed (can be All_Checks to suppress all checks).
64 procedure Resolve_Discrete_Subtype_Indication
67 -- Resolve subtype indications in choices (case statements and
68 -- aggregates) and in index constraints. Note that the resulting Etype
69 -- of the subtype indication node is set to the Etype of the contained
70 -- range (i.e. an Itype is not constructed for the actual subtype).
72 procedure Resolve_Entry (Entry_Name : Node_Id);
73 -- Find name of entry being called, and resolve prefix of name with its
74 -- own type. For now we assume that the prefix cannot be overloaded and
75 -- the name of the entry plays no role in the resolution.
77 procedure Analyze_And_Resolve (N : Node_Id);
78 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id);
79 procedure Analyze_And_Resolve
83 procedure Analyze_And_Resolve
86 -- These routines combine the effect of Analyze and Resolve. If a Suppress
87 -- argument is present, then the analysis is done with the specified check
88 -- suppressed (can be All_Checks to suppress all checks). These checks are
89 -- suppressed for both the analysis and resolution. If the type argument
90 -- is not present, then the Etype of the expression after the Analyze
91 -- call is used for the Resolve.
93 procedure Check_Parameterless_Call (N : Node_Id);
94 -- Several forms of names can denote calls to entities without para-
95 -- meters. The context determines whether the name denotes the entity
96 -- or a call to it. When it is a call, the node must be rebuilt
97 -- accordingly (deprocedured, in A68 terms) and renalyzed to obtain
98 -- possible interpretations.
100 -- The name may be that of an overloadable construct, or it can be an
101 -- explicit dereference of a prefix that denotes an access to subprogram.
102 -- In that case, we want to convert the name into a call only if the
103 -- context requires the return type of the subprogram. Finally, a
104 -- parameterless protected subprogram appears as a selected component.
106 -- The parameter T is the Typ for the corresponding resolve call.
108 procedure Pre_Analyze_And_Resolve (N : Node_Id; T : Entity_Id);
109 -- Performs a pre-analysis of expression node N. During pre-analysis
110 -- N is analyzed and then resolved against type T, but no expansion
111 -- is carried out for N or its children. For more info on pre-analysis
112 -- read the spec of Sem.
114 procedure Pre_Analyze_And_Resolve (N : Node_Id);
115 -- Same, but use type of node because context does not impose a single