1/* Functions for deciding which macros are currently in scope.
2   Copyright 2002 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 2 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, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, USA.  */
21
22#include "defs.h"
23
24#include "macroscope.h"
25#include "symtab.h"
26#include "source.h"
27#include "target.h"
28#include "frame.h"
29#include "inferior.h"
30#include "complaints.h"
31
32
33struct macro_scope *
34sal_macro_scope (struct symtab_and_line sal)
35{
36  struct macro_source_file *main, *inclusion;
37  struct macro_scope *ms;
38
39  if (! sal.symtab
40      || ! sal.symtab->macro_table)
41    return 0;
42
43  ms = (struct macro_scope *) xmalloc (sizeof (*ms));
44
45  main = macro_main (sal.symtab->macro_table);
46  inclusion = macro_lookup_inclusion (main, sal.symtab->filename);
47
48  if (inclusion)
49    {
50      ms->file = inclusion;
51      ms->line = sal.line;
52    }
53  else
54    {
55      /* There are, unfortunately, cases where a compilation unit can
56         have a symtab for a source file that doesn't appear in the
57         macro table.  For example, at the moment, Dwarf doesn't have
58         any way in the .debug_macinfo section to describe the effect
59         of #line directives, so if you debug a YACC parser you'll get
60         a macro table which only mentions the .c files generated by
61         YACC, but symtabs that mention the .y files consumed by YACC.
62
63         In the long run, we should extend the Dwarf macro info
64         representation to handle #line directives, and get GCC to
65         emit it.
66
67         For the time being, though, we'll just treat these as
68         occurring at the end of the main source file.  */
69      ms->file = main;
70      ms->line = -1;
71
72      complaint (&symfile_complaints,
73                 "symtab found for `%s', but that file\n"
74                 "is not covered in the compilation unit's macro information",
75                 sal.symtab->filename);
76    }
77
78  return ms;
79}
80
81
82struct macro_scope *
83default_macro_scope (void)
84{
85  struct symtab_and_line sal;
86  struct macro_source_file *main;
87  struct macro_scope *ms;
88
89  /* If there's a selected frame, use its PC.  */
90  if (deprecated_selected_frame)
91    sal = find_pc_line (get_frame_pc (deprecated_selected_frame), 0);
92
93  /* If the target has any registers at all, then use its PC.  Why we
94     would have registers but no stack, I'm not sure.  */
95  else if (target_has_registers)
96    sal = find_pc_line (read_pc (), 0);
97
98  /* If all else fails, fall back to the current listing position.  */
99  else
100    {
101      /* Don't call select_source_symtab here.  That can raise an
102         error if symbols aren't loaded, but GDB calls the expression
103         evaluator in all sorts of contexts.
104
105         For example, commands like `set width' call the expression
106         evaluator to evaluate their numeric arguments.  If the
107         current language is C, then that may call this function to
108         choose a scope for macro expansion.  If you don't have any
109         symbol files loaded, then get_current_or_default would raise an
110         error.  But `set width' shouldn't raise an error just because
111         it can't decide which scope to macro-expand its argument in.  */
112      struct symtab_and_line cursal =
113      			get_current_source_symtab_and_line ();
114
115      sal.symtab = cursal.symtab;
116      sal.line = cursal.line;
117    }
118
119  return sal_macro_scope (sal);
120}
121
122
123/* Look up the definition of the macro named NAME in scope at the source
124   location given by BATON, which must be a pointer to a `struct
125   macro_scope' structure.  */
126struct macro_definition *
127standard_macro_lookup (const char *name, void *baton)
128{
129  struct macro_scope *ms = (struct macro_scope *) baton;
130
131  return macro_lookup_definition (ms->file, ms->line, name);
132}
133