1 /* Get info from stack frames; convert between frames, blocks,
2 functions and pc values.
4 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
5 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009,
6 2010, 2011 Free Software Foundation, Inc.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
34 #include "gdb_assert.h"
35 #include "dummy-frame.h"
39 #include "inline-frame.h"
42 /* Return the innermost lexical block in execution in a specified
43 stack frame. The frame address is assumed valid.
45 If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
46 address we used to choose the block. We use this to find a source
47 line, to decide which macro definitions are in scope.
49 The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
50 PC, and may not really be a valid PC at all. For example, in the
51 caller of a function declared to never return, the code at the
52 return address will never be reached, so the call instruction may
53 be the very last instruction in the block. So the address we use
54 to choose the block is actually one byte before the return address
55 --- hopefully pointing us at the call instruction, or its delay
59 get_frame_block (struct frame_info *frame, CORE_ADDR *addr_in_block)
65 if (!get_frame_address_in_block_if_available (frame, &pc))
71 bl = block_for_pc (pc);
75 inline_count = frame_inlined_callees (frame);
77 while (inline_count > 0)
79 if (block_inlined_p (bl))
82 bl = BLOCK_SUPERBLOCK (bl);
83 gdb_assert (bl != NULL);
90 get_pc_function_start (CORE_ADDR pc)
93 struct minimal_symbol *msymbol;
95 bl = block_for_pc (pc);
98 struct symbol *symbol = block_linkage_function (bl);
102 bl = SYMBOL_BLOCK_VALUE (symbol);
103 return BLOCK_START (bl);
107 msymbol = lookup_minimal_symbol_by_pc (pc);
110 CORE_ADDR fstart = SYMBOL_VALUE_ADDRESS (msymbol);
112 if (find_pc_section (fstart))
119 /* Return the symbol for the function executing in frame FRAME. */
122 get_frame_function (struct frame_info *frame)
124 struct block *bl = get_frame_block (frame, 0);
129 while (BLOCK_FUNCTION (bl) == NULL && BLOCK_SUPERBLOCK (bl) != NULL)
130 bl = BLOCK_SUPERBLOCK (bl);
132 return BLOCK_FUNCTION (bl);
136 /* Return the function containing pc value PC in section SECTION.
137 Returns 0 if function is not known. */
140 find_pc_sect_function (CORE_ADDR pc, struct obj_section *section)
142 struct block *b = block_for_pc_sect (pc, section);
146 return block_linkage_function (b);
149 /* Return the function containing pc value PC.
150 Returns 0 if function is not known.
151 Backward compatibility, no section */
154 find_pc_function (CORE_ADDR pc)
156 return find_pc_sect_function (pc, find_pc_mapped_section (pc));
159 /* These variables are used to cache the most recent result
160 of find_pc_partial_function. */
162 static CORE_ADDR cache_pc_function_low = 0;
163 static CORE_ADDR cache_pc_function_high = 0;
164 static char *cache_pc_function_name = 0;
165 static struct obj_section *cache_pc_function_section = NULL;
167 /* Clear cache, e.g. when symbol table is discarded. */
170 clear_pc_function_cache (void)
172 cache_pc_function_low = 0;
173 cache_pc_function_high = 0;
174 cache_pc_function_name = (char *) 0;
175 cache_pc_function_section = NULL;
178 /* Finds the "function" (text symbol) that is smaller than PC but
179 greatest of all of the potential text symbols in SECTION. Sets
180 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
181 If ENDADDR is non-null, then set *ENDADDR to be the end of the
182 function (exclusive), but passing ENDADDR as non-null means that
183 the function might cause symbols to be read. This function either
184 succeeds or fails (not halfway succeeds). If it succeeds, it sets
185 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
186 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
189 /* Backward compatibility, no section argument. */
192 find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address,
195 struct obj_section *section;
197 struct minimal_symbol *msymbol;
198 struct symtab *symtab = NULL;
199 struct objfile *objfile;
203 /* To ensure that the symbol returned belongs to the correct setion
204 (and that the last [random] symbol from the previous section
205 isn't returned) try to find the section containing PC. First try
206 the overlay code (which by default returns NULL); and second try
207 the normal section code (which almost always succeeds). */
208 section = find_pc_overlay (pc);
210 section = find_pc_section (pc);
212 mapped_pc = overlay_mapped_address (pc, section);
214 if (mapped_pc >= cache_pc_function_low
215 && mapped_pc < cache_pc_function_high
216 && section == cache_pc_function_section)
217 goto return_cached_value;
219 msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
220 ALL_OBJFILES (objfile)
223 symtab = objfile->sf->qf->find_pc_sect_symtab (objfile, msymbol,
224 mapped_pc, section, 0);
231 /* Checking whether the msymbol has a larger value is for the
232 "pathological" case mentioned in print_frame_info. */
233 f = find_pc_sect_function (mapped_pc, section);
236 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
237 >= SYMBOL_VALUE_ADDRESS (msymbol))))
239 cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
240 cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
241 cache_pc_function_name = SYMBOL_LINKAGE_NAME (f);
242 cache_pc_function_section = section;
243 goto return_cached_value;
247 /* Not in the normal symbol tables, see if the pc is in a known
248 section. If it's not, then give up. This ensures that anything
249 beyond the end of the text seg doesn't appear to be part of the
250 last function in the text segment. */
255 /* Must be in the minimal symbol table. */
258 /* No available symbol. */
268 cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
269 cache_pc_function_name = SYMBOL_LINKAGE_NAME (msymbol);
270 cache_pc_function_section = section;
272 /* If the minimal symbol has a size, use it for the cache.
273 Otherwise use the lesser of the next minimal symbol in the same
274 section, or the end of the section, as the end of the
277 if (MSYMBOL_SIZE (msymbol) != 0)
278 cache_pc_function_high = cache_pc_function_low + MSYMBOL_SIZE (msymbol);
281 /* Step over other symbols at this same address, and symbols in
282 other sections, to find the next symbol in this section with
283 a different address. */
285 for (i = 1; SYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++)
287 if (SYMBOL_VALUE_ADDRESS (msymbol + i)
288 != SYMBOL_VALUE_ADDRESS (msymbol)
289 && SYMBOL_OBJ_SECTION (msymbol + i)
290 == SYMBOL_OBJ_SECTION (msymbol))
294 if (SYMBOL_LINKAGE_NAME (msymbol + i) != NULL
295 && SYMBOL_VALUE_ADDRESS (msymbol + i)
296 < obj_section_endaddr (section))
297 cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
299 /* We got the start address from the last msymbol in the objfile.
300 So the end address is the end of the section. */
301 cache_pc_function_high = obj_section_endaddr (section);
308 if (pc_in_unmapped_range (pc, section))
309 *address = overlay_unmapped_address (cache_pc_function_low, section);
311 *address = cache_pc_function_low;
315 *name = cache_pc_function_name;
319 if (pc_in_unmapped_range (pc, section))
321 /* Because the high address is actually beyond the end of
322 the function (and therefore possibly beyond the end of
323 the overlay), we must actually convert (high - 1) and
324 then add one to that. */
326 *endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
330 *endaddr = cache_pc_function_high;
336 /* Return the innermost stack frame executing inside of BLOCK, or NULL
337 if there is no such frame. If BLOCK is NULL, just return NULL. */
340 block_innermost_frame (struct block *block)
342 struct frame_info *frame;
349 start = BLOCK_START (block);
350 end = BLOCK_END (block);
352 frame = get_current_frame ();
353 while (frame != NULL)
355 struct block *frame_block = get_frame_block (frame, NULL);
356 if (frame_block != NULL && contained_in (frame_block, block))
359 frame = get_prev_frame (frame);