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
;
166 static int cache_pc_function_is_gnu_ifunc
= 0;
168 /* Clear cache, e.g. when symbol table is discarded. */
171 clear_pc_function_cache (void)
173 cache_pc_function_low
= 0;
174 cache_pc_function_high
= 0;
175 cache_pc_function_name
= (char *) 0;
176 cache_pc_function_section
= NULL
;
177 cache_pc_function_is_gnu_ifunc
= 0;
180 /* Finds the "function" (text symbol) that is smaller than PC but
181 greatest of all of the potential text symbols in SECTION. Sets
182 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
183 If ENDADDR is non-null, then set *ENDADDR to be the end of the
184 function (exclusive), but passing ENDADDR as non-null means that
185 the function might cause symbols to be read. If IS_GNU_IFUNC_P is provided
186 *IS_GNU_IFUNC_P is set to 1 on return if the function is STT_GNU_IFUNC.
187 This function either succeeds or fails (not halfway succeeds). If it
188 succeeds, it sets *NAME, *ADDRESS, and *ENDADDR to real information and
189 returns 1. If it fails, it sets *NAME, *ADDRESS, *ENDADDR and
190 *IS_GNU_IFUNC_P to zero and returns 0. */
192 /* Backward compatibility, no section argument. */
195 find_pc_partial_function_gnu_ifunc (CORE_ADDR pc
, char **name
,
196 CORE_ADDR
*address
, CORE_ADDR
*endaddr
,
199 struct obj_section
*section
;
201 struct minimal_symbol
*msymbol
;
202 struct symtab
*symtab
= NULL
;
203 struct objfile
*objfile
;
207 /* To ensure that the symbol returned belongs to the correct setion
208 (and that the last [random] symbol from the previous section
209 isn't returned) try to find the section containing PC. First try
210 the overlay code (which by default returns NULL); and second try
211 the normal section code (which almost always succeeds). */
212 section
= find_pc_overlay (pc
);
214 section
= find_pc_section (pc
);
216 mapped_pc
= overlay_mapped_address (pc
, section
);
218 if (mapped_pc
>= cache_pc_function_low
219 && mapped_pc
< cache_pc_function_high
220 && section
== cache_pc_function_section
)
221 goto return_cached_value
;
223 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
224 ALL_OBJFILES (objfile
)
227 symtab
= objfile
->sf
->qf
->find_pc_sect_symtab (objfile
, msymbol
,
228 mapped_pc
, section
, 0);
235 /* Checking whether the msymbol has a larger value is for the
236 "pathological" case mentioned in print_frame_info. */
237 f
= find_pc_sect_function (mapped_pc
, section
);
240 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
241 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
243 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
244 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
245 cache_pc_function_name
= SYMBOL_LINKAGE_NAME (f
);
246 cache_pc_function_section
= section
;
247 cache_pc_function_is_gnu_ifunc
= TYPE_GNU_IFUNC (SYMBOL_TYPE (f
));
248 goto return_cached_value
;
252 /* Not in the normal symbol tables, see if the pc is in a known
253 section. If it's not, then give up. This ensures that anything
254 beyond the end of the text seg doesn't appear to be part of the
255 last function in the text segment. */
260 /* Must be in the minimal symbol table. */
263 /* No available symbol. */
270 if (is_gnu_ifunc_p
!= NULL
)
275 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
276 cache_pc_function_name
= SYMBOL_LINKAGE_NAME (msymbol
);
277 cache_pc_function_section
= section
;
278 cache_pc_function_is_gnu_ifunc
= MSYMBOL_TYPE (msymbol
) == mst_text_gnu_ifunc
;
280 /* If the minimal symbol has a size, use it for the cache.
281 Otherwise use the lesser of the next minimal symbol in the same
282 section, or the end of the section, as the end of the
285 if (MSYMBOL_SIZE (msymbol
) != 0)
286 cache_pc_function_high
= cache_pc_function_low
+ MSYMBOL_SIZE (msymbol
);
289 /* Step over other symbols at this same address, and symbols in
290 other sections, to find the next symbol in this section with
291 a different address. */
293 for (i
= 1; SYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
; i
++)
295 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
)
296 != SYMBOL_VALUE_ADDRESS (msymbol
)
297 && SYMBOL_OBJ_SECTION (msymbol
+ i
)
298 == SYMBOL_OBJ_SECTION (msymbol
))
302 if (SYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
303 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
)
304 < obj_section_endaddr (section
))
305 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
307 /* We got the start address from the last msymbol in the objfile.
308 So the end address is the end of the section. */
309 cache_pc_function_high
= obj_section_endaddr (section
);
316 if (pc_in_unmapped_range (pc
, section
))
317 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
319 *address
= cache_pc_function_low
;
323 *name
= cache_pc_function_name
;
327 if (pc_in_unmapped_range (pc
, section
))
329 /* Because the high address is actually beyond the end of
330 the function (and therefore possibly beyond the end of
331 the overlay), we must actually convert (high - 1) and
332 then add one to that. */
334 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
338 *endaddr
= cache_pc_function_high
;
342 *is_gnu_ifunc_p
= cache_pc_function_is_gnu_ifunc
;
347 /* See find_pc_partial_function_gnu_ifunc, only the IS_GNU_IFUNC_P parameter
348 is omitted here for backward API compatibility. */
351 find_pc_partial_function (CORE_ADDR pc
, char **name
, CORE_ADDR
*address
,
354 return find_pc_partial_function_gnu_ifunc (pc
, name
, address
, endaddr
, NULL
);
357 /* Return the innermost stack frame executing inside of BLOCK, or NULL
358 if there is no such frame. If BLOCK is NULL, just return NULL. */
361 block_innermost_frame (const struct block
*block
)
363 struct frame_info
*frame
;
370 start
= BLOCK_START (block
);
371 end
= BLOCK_END (block
);
373 frame
= get_current_frame ();
374 while (frame
!= NULL
)
376 struct block
*frame_block
= get_frame_block (frame
, NULL
);
377 if (frame_block
!= NULL
&& contained_in (frame_block
, block
))
380 frame
= get_prev_frame (frame
);