1/* Functions for deciding which macros are currently in scope.
2   Copyright (C) 2002, 2007 Free Software Foundation, Inc.
3   Contributed by Red Hat, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21
22#include "macroscope.h"
23#include "symtab.h"
24#include "source.h"
25#include "target.h"
26#include "frame.h"
27#include "inferior.h"
28#include "complaints.h"
29
30
31struct macro_scope *
32sal_macro_scope (struct symtab_and_line sal)
33{
34  struct macro_source_file *main_file, *inclusion;
35  struct macro_scope *ms;
36
37  if (! sal.symtab
38      || ! sal.symtab->macro_table)
39    return 0;
40
41  ms = (struct macro_scope *) xmalloc (sizeof (*ms));
42
43  main_file = macro_main (sal.symtab->macro_table);
44  inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename);
45
46  if (inclusion)
47    {
48      ms->file = inclusion;
49      ms->line = sal.line;
50    }
51  else
52    {
53      /* There are, unfortunately, cases where a compilation unit can
54         have a symtab for a source file that doesn't appear in the
55         macro table.  For example, at the moment, Dwarf doesn't have
56         any way in the .debug_macinfo section to describe the effect
57         of #line directives, so if you debug a YACC parser you'll get
58         a macro table which only mentions the .c files generated by
59         YACC, but symtabs that mention the .y files consumed by YACC.
60
61         In the long run, we should extend the Dwarf macro info
62         representation to handle #line directives, and get GCC to
63         emit it.
64
65         For the time being, though, we'll just treat these as
66         occurring at the end of the main source file.  */
67      ms->file = main_file;
68      ms->line = -1;
69
70      complaint (&symfile_complaints,
71                 _("symtab found for `%s', but that file\n"
72                 "is not covered in the compilation unit's macro information"),
73                 sal.symtab->filename);
74    }
75
76  return ms;
77}
78
79
80struct macro_scope *
81default_macro_scope (void)
82{
83  struct symtab_and_line sal;
84  struct macro_scope *ms;
85  struct frame_info *frame;
86
87  /* If there's a selected frame, use its PC.  */
88  frame = deprecated_safe_get_selected_frame ();
89  if (frame)
90    sal = find_pc_line (get_frame_pc (frame), 0);
91
92  /* Fall back to the current listing position.  */
93  else
94    {
95      /* Don't call select_source_symtab here.  That can raise an
96         error if symbols aren't loaded, but GDB calls the expression
97         evaluator in all sorts of contexts.
98
99         For example, commands like `set width' call the expression
100         evaluator to evaluate their numeric arguments.  If the
101         current language is C, then that may call this function to
102         choose a scope for macro expansion.  If you don't have any
103         symbol files loaded, then get_current_or_default would raise an
104         error.  But `set width' shouldn't raise an error just because
105         it can't decide which scope to macro-expand its argument in.  */
106      struct symtab_and_line cursal =
107      			get_current_source_symtab_and_line ();
108
109      sal.symtab = cursal.symtab;
110      sal.line = cursal.line;
111    }
112
113  return sal_macro_scope (sal);
114}
115
116
117/* Look up the definition of the macro named NAME in scope at the source
118   location given by BATON, which must be a pointer to a `struct
119   macro_scope' structure.  */
120struct macro_definition *
121standard_macro_lookup (const char *name, void *baton)
122{
123  struct macro_scope *ms = (struct macro_scope *) baton;
124
125  return macro_lookup_definition (ms->file, ms->line, name);
126}
127