1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ R E S --
-- --
-- S p e c --
-- --
-- --
-- Copyright (C) 1992-1999 Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- 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 Snames; use Snames;
with Types; use Types;
package Sem_Res is
-- As described in Sem_Ch4, 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 analyze, and also call the
-- expander for possibly expansion of the completely type resolved node.
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_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 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 para-
-- meters. 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 (deprocedured, in A68 terms) and renalyzed 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 Pre_Analyze_And_Resolve (N : Node_Id; T : Entity_Id);
-- Performs a pre-analysis of expression node N. During pre-analysis
-- N is analyzed and then resolved against type T, but no expansion
-- is carried out for N or its children. For more info on pre-analysis
-- read the spec of Sem.
procedure Pre_Analyze_And_Resolve (N : Node_Id);
-- Same, but use type of node because context does not impose a single
-- type.
end Sem_Res;
|
