summaryrefslogtreecommitdiff
path: root/gdb/block.c
blob: 35915febf2581a16eef4b35e3512a020932dec37 (plain)
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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
/* Block-related functions for the GNU debugger, GDB.

   Copyright (C) 2003, 2007 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT 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
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"
#include "block.h"
#include "symtab.h"
#include "symfile.h"
#include "gdb_obstack.h"
#include "cp-support.h"

/* This is used by struct block to store namespace-related info for
   C++ files, namely using declarations and the current namespace in
   scope.  */

struct block_namespace_info
{
  const char *scope;
  struct using_direct *using;
};

static void block_initialize_namespace (struct block *block,
					struct obstack *obstack);

/* Return Nonzero if block a is lexically nested within block b,
   or if a and b have the same pc range.
   Return zero otherwise. */

int
contained_in (const struct block *a, const struct block *b)
{
  if (!a || !b)
    return 0;
  return BLOCK_START (a) >= BLOCK_START (b)
    && BLOCK_END (a) <= BLOCK_END (b);
}


/* Return the symbol for the function which contains a specified
   lexical block, described by a struct block BL.  */

struct symbol *
block_function (const struct block *bl)
{
  while (BLOCK_FUNCTION (bl) == 0 && BLOCK_SUPERBLOCK (bl) != 0)
    bl = BLOCK_SUPERBLOCK (bl);

  return BLOCK_FUNCTION (bl);
}

/* Return the blockvector immediately containing the innermost lexical block
   containing the specified pc value and section, or 0 if there is none.
   PINDEX is a pointer to the index value of the block.  If PINDEX
   is NULL, we don't pass this information back to the caller.  */

struct blockvector *
blockvector_for_pc_sect (CORE_ADDR pc, struct bfd_section *section,
			 int *pindex, struct symtab *symtab)
{
  struct block *b;
  int bot, top, half;
  struct blockvector *bl;

  if (symtab == 0)		/* if no symtab specified by caller */
    {
      /* First search all symtabs for one whose file contains our pc */
      symtab = find_pc_sect_symtab (pc, section);
      if (symtab == 0)
	return 0;
    }

  bl = BLOCKVECTOR (symtab);
  b = BLOCKVECTOR_BLOCK (bl, 0);

  /* Then search that symtab for the smallest block that wins.  */
  /* Use binary search to find the last block that starts before PC.  */

  bot = 0;
  top = BLOCKVECTOR_NBLOCKS (bl);

  while (top - bot > 1)
    {
      half = (top - bot + 1) >> 1;
      b = BLOCKVECTOR_BLOCK (bl, bot + half);
      if (BLOCK_START (b) <= pc)
	bot += half;
      else
	top = bot + half;
    }

  /* Now search backward for a block that ends after PC.  */

  while (bot >= 0)
    {
      b = BLOCKVECTOR_BLOCK (bl, bot);
      if (BLOCK_END (b) > pc)
	{
	  if (pindex)
	    *pindex = bot;
	  return bl;
	}
      bot--;
    }
  return 0;
}

/* Return the blockvector immediately containing the innermost lexical block
   containing the specified pc value, or 0 if there is none.
   Backward compatibility, no section.  */

struct blockvector *
blockvector_for_pc (CORE_ADDR pc, int *pindex)
{
  return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
				  pindex, NULL);
}

/* Return the innermost lexical block containing the specified pc value
   in the specified section, or 0 if there is none.  */

struct block *
block_for_pc_sect (CORE_ADDR pc, struct bfd_section *section)
{
  struct blockvector *bl;
  int index;

  bl = blockvector_for_pc_sect (pc, section, &index, NULL);
  if (bl)
    return BLOCKVECTOR_BLOCK (bl, index);
  return 0;
}

/* Return the innermost lexical block containing the specified pc value,
   or 0 if there is none.  Backward compatibility, no section.  */

struct block *
block_for_pc (CORE_ADDR pc)
{
  return block_for_pc_sect (pc, find_pc_mapped_section (pc));
}

/* Now come some functions designed to deal with C++ namespace issues.
   The accessors are safe to use even in the non-C++ case.  */

/* This returns the namespace that BLOCK is enclosed in, or "" if it
   isn't enclosed in a namespace at all.  This travels the chain of
   superblocks looking for a scope, if necessary.  */

const char *
block_scope (const struct block *block)
{
  for (; block != NULL; block = BLOCK_SUPERBLOCK (block))
    {
      if (BLOCK_NAMESPACE (block) != NULL
	  && BLOCK_NAMESPACE (block)->scope != NULL)
	return BLOCK_NAMESPACE (block)->scope;
    }

  return "";
}

/* Set BLOCK's scope member to SCOPE; if needed, allocate memory via
   OBSTACK.  (It won't make a copy of SCOPE, however, so that already
   has to be allocated correctly.)  */

void
block_set_scope (struct block *block, const char *scope,
		 struct obstack *obstack)
{
  block_initialize_namespace (block, obstack);

  BLOCK_NAMESPACE (block)->scope = scope;
}

/* This returns the first using directives associated to BLOCK, if
   any.  */

/* FIXME: carlton/2003-04-23: This uses the fact that we currently
   only have using directives in static blocks, because we only
   generate using directives from anonymous namespaces.  Eventually,
   when we support using directives everywhere, we'll want to replace
   this by some iterator functions.  */

struct using_direct *
block_using (const struct block *block)
{
  const struct block *static_block = block_static_block (block);

  if (static_block == NULL
      || BLOCK_NAMESPACE (static_block) == NULL)
    return NULL;
  else
    return BLOCK_NAMESPACE (static_block)->using;
}

/* Set BLOCK's using member to USING; if needed, allocate memory via
   OBSTACK.  (It won't make a copy of USING, however, so that already
   has to be allocated correctly.)  */

void
block_set_using (struct block *block,
		 struct using_direct *using,
		 struct obstack *obstack)
{
  block_initialize_namespace (block, obstack);

  BLOCK_NAMESPACE (block)->using = using;
}

/* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and
   ititialize its members to zero.  */

static void
block_initialize_namespace (struct block *block, struct obstack *obstack)
{
  if (BLOCK_NAMESPACE (block) == NULL)
    {
      BLOCK_NAMESPACE (block)
	= obstack_alloc (obstack, sizeof (struct block_namespace_info));
      BLOCK_NAMESPACE (block)->scope = NULL;
      BLOCK_NAMESPACE (block)->using = NULL;
    }
}

/* Return the static block associated to BLOCK.  Return NULL if block
   is NULL or if block is a global block.  */

const struct block *
block_static_block (const struct block *block)
{
  if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL)
    return NULL;

  while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL)
    block = BLOCK_SUPERBLOCK (block);

  return block;
}

/* Return the static block associated to BLOCK.  Return NULL if block
   is NULL.  */

const struct block *
block_global_block (const struct block *block)
{
  if (block == NULL)
    return NULL;

  while (BLOCK_SUPERBLOCK (block) != NULL)
    block = BLOCK_SUPERBLOCK (block);

  return block;
}

/* Allocate a block on OBSTACK, and initialize its elements to
   zero/NULL.  This is useful for creating "dummy" blocks that don't
   correspond to actual source files.

   Warning: it sets the block's BLOCK_DICT to NULL, which isn't a
   valid value.  If you really don't want the block to have a
   dictionary, then you should subsequently set its BLOCK_DICT to
   dict_create_linear (obstack, NULL).  */

struct block *
allocate_block (struct obstack *obstack)
{
  struct block *bl = obstack_alloc (obstack, sizeof (struct block));

  BLOCK_START (bl) = 0;
  BLOCK_END (bl) = 0;
  BLOCK_FUNCTION (bl) = NULL;
  BLOCK_SUPERBLOCK (bl) = NULL;
  BLOCK_DICT (bl) = NULL;
  BLOCK_NAMESPACE (bl) = NULL;
  BLOCK_GCC_COMPILED (bl) = 0;

  return bl;
}