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 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"
41 /* Prototypes for exported functions. */
43 void _initialize_blockframe (void);
45 /* Return the innermost lexical block in execution
46 in a specified stack frame. The frame address is assumed valid.
48 If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
49 address we used to choose the block. We use this to find a source
50 line, to decide which macro definitions are in scope.
52 The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
53 PC, and may not really be a valid PC at all. For example, in the
54 caller of a function declared to never return, the code at the
55 return address will never be reached, so the call instruction may
56 be the very last instruction in the block. So the address we use
57 to choose the block is actually one byte before the return address
58 --- hopefully pointing us at the call instruction, or its delay
62 get_frame_block (struct frame_info
*frame
, CORE_ADDR
*addr_in_block
)
64 const CORE_ADDR pc
= get_frame_address_in_block (frame
);
65 struct frame_info
*next_frame
;
72 bl
= block_for_pc (pc
);
76 inline_count
= frame_inlined_callees (frame
);
78 while (inline_count
> 0)
80 if (block_inlined_p (bl
))
83 bl
= BLOCK_SUPERBLOCK (bl
);
84 gdb_assert (bl
!= NULL
);
91 get_pc_function_start (CORE_ADDR pc
)
94 struct minimal_symbol
*msymbol
;
96 bl
= block_for_pc (pc
);
99 struct symbol
*symbol
= block_linkage_function (bl
);
103 bl
= SYMBOL_BLOCK_VALUE (symbol
);
104 return BLOCK_START (bl
);
108 msymbol
= lookup_minimal_symbol_by_pc (pc
);
111 CORE_ADDR fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
113 if (find_pc_section (fstart
))
120 /* Return the symbol for the function executing in frame FRAME. */
123 get_frame_function (struct frame_info
*frame
)
125 struct block
*bl
= get_frame_block (frame
, 0);
130 while (BLOCK_FUNCTION (bl
) == NULL
&& BLOCK_SUPERBLOCK (bl
) != NULL
)
131 bl
= BLOCK_SUPERBLOCK (bl
);
133 return BLOCK_FUNCTION (bl
);
137 /* Return the function containing pc value PC in section SECTION.
138 Returns 0 if function is not known. */
141 find_pc_sect_function (CORE_ADDR pc
, struct obj_section
*section
)
143 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. Backward compatibility, no section */
153 find_pc_function (CORE_ADDR pc
)
155 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
158 /* These variables are used to cache the most recent result
159 * of find_pc_partial_function. */
161 static CORE_ADDR cache_pc_function_low
= 0;
162 static CORE_ADDR cache_pc_function_high
= 0;
163 static char *cache_pc_function_name
= 0;
164 static struct obj_section
*cache_pc_function_section
= NULL
;
166 /* Clear cache, e.g. when symbol table is discarded. */
169 clear_pc_function_cache (void)
171 cache_pc_function_low
= 0;
172 cache_pc_function_high
= 0;
173 cache_pc_function_name
= (char *) 0;
174 cache_pc_function_section
= NULL
;
177 /* Finds the "function" (text symbol) that is smaller than PC but
178 greatest of all of the potential text symbols in SECTION. Sets
179 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
180 If ENDADDR is non-null, then set *ENDADDR to be the end of the
181 function (exclusive), but passing ENDADDR as non-null means that
182 the function might cause symbols to be read. This function either
183 succeeds or fails (not halfway succeeds). If it succeeds, it sets
184 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
185 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
188 /* Backward compatibility, no section argument. */
191 find_pc_partial_function (CORE_ADDR pc
, char **name
, CORE_ADDR
*address
,
194 struct obj_section
*section
;
195 struct partial_symtab
*pst
;
197 struct minimal_symbol
*msymbol
;
198 struct partial_symbol
*psb
;
202 /* To ensure that the symbol returned belongs to the correct setion
203 (and that the last [random] symbol from the previous section
204 isn't returned) try to find the section containing PC. First try
205 the overlay code (which by default returns NULL); and second try
206 the normal section code (which almost always succeeds). */
207 section
= find_pc_overlay (pc
);
209 section
= find_pc_section (pc
);
211 mapped_pc
= overlay_mapped_address (pc
, section
);
213 if (mapped_pc
>= cache_pc_function_low
214 && mapped_pc
< cache_pc_function_high
215 && section
== cache_pc_function_section
)
216 goto return_cached_value
;
218 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
219 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
222 /* Need to read the symbols to get a good value for the end address. */
223 if (endaddr
!= NULL
&& !pst
->readin
)
225 /* Need to get the terminal in case symbol-reading produces
227 target_terminal_ours_for_output ();
228 PSYMTAB_TO_SYMTAB (pst
);
233 /* Checking whether the msymbol has a larger value is for the
234 "pathological" case mentioned in print_frame_info. */
235 f
= find_pc_sect_function (mapped_pc
, section
);
238 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
239 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
241 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
242 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
243 cache_pc_function_name
= SYMBOL_LINKAGE_NAME (f
);
244 cache_pc_function_section
= section
;
245 goto return_cached_value
;
250 /* Now that static symbols go in the minimal symbol table, perhaps
251 we could just ignore the partial symbols. But at least for now
252 we use the partial or minimal symbol, whichever is larger. */
253 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
256 && (msymbol
== NULL
||
257 (SYMBOL_VALUE_ADDRESS (psb
)
258 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
260 /* This case isn't being cached currently. */
262 *address
= SYMBOL_VALUE_ADDRESS (psb
);
264 *name
= SYMBOL_LINKAGE_NAME (psb
);
265 /* endaddr non-NULL can't happen here. */
271 /* Not in the normal symbol tables, see if the pc is in a known section.
272 If it's not, then give up. This ensures that anything beyond the end
273 of the text seg doesn't appear to be part of the last function in the
279 /* Must be in the minimal symbol table. */
282 /* No available symbol. */
292 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
293 cache_pc_function_name
= SYMBOL_LINKAGE_NAME (msymbol
);
294 cache_pc_function_section
= section
;
296 /* If the minimal symbol has a size, use it for the cache.
297 Otherwise use the lesser of the next minimal symbol in the same
298 section, or the end of the section, as the end of the
301 if (MSYMBOL_SIZE (msymbol
) != 0)
302 cache_pc_function_high
= cache_pc_function_low
+ MSYMBOL_SIZE (msymbol
);
305 /* Step over other symbols at this same address, and symbols in
306 other sections, to find the next symbol in this section with
307 a different address. */
309 for (i
= 1; SYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
; i
++)
311 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
312 && SYMBOL_OBJ_SECTION (msymbol
+ i
) == SYMBOL_OBJ_SECTION (msymbol
))
316 if (SYMBOL_LINKAGE_NAME (msymbol
+ i
) != NULL
317 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < obj_section_endaddr (section
))
318 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
320 /* We got the start address from the last msymbol in the objfile.
321 So the end address is the end of the section. */
322 cache_pc_function_high
= obj_section_endaddr (section
);
329 if (pc_in_unmapped_range (pc
, section
))
330 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
332 *address
= cache_pc_function_low
;
336 *name
= cache_pc_function_name
;
340 if (pc_in_unmapped_range (pc
, section
))
342 /* Because the high address is actually beyond the end of
343 the function (and therefore possibly beyond the end of
344 the overlay), we must actually convert (high - 1) and
345 then add one to that. */
347 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
351 *endaddr
= cache_pc_function_high
;
357 /* Return the innermost stack frame executing inside of BLOCK,
358 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
361 block_innermost_frame (struct block
*block
)
363 struct frame_info
*frame
;
366 CORE_ADDR calling_pc
;
371 start
= BLOCK_START (block
);
372 end
= BLOCK_END (block
);
374 frame
= get_current_frame ();
375 while (frame
!= NULL
)
377 struct block
*frame_block
= get_frame_block (frame
, NULL
);
378 if (frame_block
!= NULL
&& contained_in (frame_block
, block
))
381 frame
= get_prev_frame (frame
);