| /* Get info from stack frames; convert between frames, blocks, |
| functions and pc values. |
| |
| Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
| 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009 |
| 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "symtab.h" |
| #include "bfd.h" |
| #include "objfiles.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "value.h" |
| #include "target.h" |
| #include "inferior.h" |
| #include "annotate.h" |
| #include "regcache.h" |
| #include "gdb_assert.h" |
| #include "dummy-frame.h" |
| #include "command.h" |
| #include "gdbcmd.h" |
| #include "block.h" |
| |
| /* Prototypes for exported functions. */ |
| |
| void _initialize_blockframe (void); |
| |
| /* Return the innermost lexical block in execution |
| in a specified stack frame. The frame address is assumed valid. |
| |
| If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code |
| address we used to choose the block. We use this to find a source |
| line, to decide which macro definitions are in scope. |
| |
| The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's |
| PC, and may not really be a valid PC at all. For example, in the |
| caller of a function declared to never return, the code at the |
| return address will never be reached, so the call instruction may |
| be the very last instruction in the block. So the address we use |
| to choose the block is actually one byte before the return address |
| --- hopefully pointing us at the call instruction, or its delay |
| slot instruction. */ |
| |
| struct block * |
| get_frame_block (struct frame_info *frame, CORE_ADDR *addr_in_block) |
| { |
| const CORE_ADDR pc = get_frame_address_in_block (frame); |
| |
| if (addr_in_block) |
| *addr_in_block = pc; |
| |
| return block_for_pc (pc); |
| } |
| |
| CORE_ADDR |
| get_pc_function_start (CORE_ADDR pc) |
| { |
| struct block *bl; |
| struct minimal_symbol *msymbol; |
| |
| bl = block_for_pc (pc); |
| if (bl) |
| { |
| struct symbol *symbol = block_linkage_function (bl); |
| |
| if (symbol) |
| { |
| bl = SYMBOL_BLOCK_VALUE (symbol); |
| return BLOCK_START (bl); |
| } |
| } |
| |
| msymbol = lookup_minimal_symbol_by_pc (pc); |
| if (msymbol) |
| { |
| CORE_ADDR fstart = SYMBOL_VALUE_ADDRESS (msymbol); |
| |
| if (find_pc_section (fstart)) |
| return fstart; |
| } |
| |
| return 0; |
| } |
| |
| /* Return the symbol for the function executing in frame FRAME. */ |
| |
| struct symbol * |
| get_frame_function (struct frame_info *frame) |
| { |
| struct block *bl = get_frame_block (frame, 0); |
| if (bl == 0) |
| return 0; |
| return block_linkage_function (bl); |
| } |
| |
| |
| /* Return the function containing pc value PC in section SECTION. |
| Returns 0 if function is not known. */ |
| |
| struct symbol * |
| find_pc_sect_function (CORE_ADDR pc, struct obj_section *section) |
| { |
| struct block *b = block_for_pc_sect (pc, section); |
| if (b == 0) |
| return 0; |
| return block_linkage_function (b); |
| } |
| |
| /* Return the function containing pc value PC. |
| Returns 0 if function is not known. Backward compatibility, no section */ |
| |
| struct symbol * |
| find_pc_function (CORE_ADDR pc) |
| { |
| return find_pc_sect_function (pc, find_pc_mapped_section (pc)); |
| } |
| |
| /* These variables are used to cache the most recent result |
| * of find_pc_partial_function. */ |
| |
| static CORE_ADDR cache_pc_function_low = 0; |
| static CORE_ADDR cache_pc_function_high = 0; |
| static char *cache_pc_function_name = 0; |
| static struct obj_section *cache_pc_function_section = NULL; |
| |
| /* Clear cache, e.g. when symbol table is discarded. */ |
| |
| void |
| clear_pc_function_cache (void) |
| { |
| cache_pc_function_low = 0; |
| cache_pc_function_high = 0; |
| cache_pc_function_name = (char *) 0; |
| cache_pc_function_section = NULL; |
| } |
| |
| /* Finds the "function" (text symbol) that is smaller than PC but |
| greatest of all of the potential text symbols in SECTION. Sets |
| *NAME and/or *ADDRESS conditionally if that pointer is non-null. |
| If ENDADDR is non-null, then set *ENDADDR to be the end of the |
| function (exclusive), but passing ENDADDR as non-null means that |
| the function might cause symbols to be read. This function either |
| succeeds or fails (not halfway succeeds). If it succeeds, it sets |
| *NAME, *ADDRESS, and *ENDADDR to real information and returns 1. |
| If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and |
| returns 0. */ |
| |
| /* Backward compatibility, no section argument. */ |
| |
| int |
| find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address, |
| CORE_ADDR *endaddr) |
| { |
| struct obj_section *section; |
| struct partial_symtab *pst; |
| struct symbol *f; |
| struct minimal_symbol *msymbol; |
| struct partial_symbol *psb; |
| int i; |
| CORE_ADDR mapped_pc; |
| |
| /* To ensure that the symbol returned belongs to the correct setion |
| (and that the last [random] symbol from the previous section |
| isn't returned) try to find the section containing PC. First try |
| the overlay code (which by default returns NULL); and second try |
| the normal section code (which almost always succeeds). */ |
| section = find_pc_overlay (pc); |
| if (section == NULL) |
| section = find_pc_section (pc); |
| |
| mapped_pc = overlay_mapped_address (pc, section); |
| |
| if (mapped_pc >= cache_pc_function_low |
| && mapped_pc < cache_pc_function_high |
| && section == cache_pc_function_section) |
| goto return_cached_value; |
| |
| msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section); |
| pst = find_pc_sect_psymtab (mapped_pc, section); |
| if (pst) |
| { |
| /* Need to read the symbols to get a good value for the end address. */ |
| if (endaddr != NULL && !pst->readin) |
| { |
| /* Need to get the terminal in case symbol-reading produces |
| output. */ |
| target_terminal_ours_for_output (); |
| PSYMTAB_TO_SYMTAB (pst); |
| } |
| |
| if (pst->readin) |
| { |
| /* Checking whether the msymbol has a larger value is for the |
| "pathological" case mentioned in print_frame_info. */ |
| f = find_pc_sect_function (mapped_pc, section); |
| if (f != NULL |
| && (msymbol == NULL |
| || (BLOCK_START (SYMBOL_BLOCK_VALUE (f)) |
| >= SYMBOL_VALUE_ADDRESS (msymbol)))) |
| { |
| cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f)); |
| cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f)); |
| cache_pc_function_name = SYMBOL_LINKAGE_NAME (f); |
| cache_pc_function_section = section; |
| goto return_cached_value; |
| } |
| } |
| else |
| { |
| /* Now that static symbols go in the minimal symbol table, perhaps |
| we could just ignore the partial symbols. But at least for now |
| we use the partial or minimal symbol, whichever is larger. */ |
| psb = find_pc_sect_psymbol (pst, mapped_pc, section); |
| |
| if (psb |
| && (msymbol == NULL || |
| (SYMBOL_VALUE_ADDRESS (psb) |
| >= SYMBOL_VALUE_ADDRESS (msymbol)))) |
| { |
| /* This case isn't being cached currently. */ |
| if (address) |
| *address = SYMBOL_VALUE_ADDRESS (psb); |
| if (name) |
| *name = SYMBOL_LINKAGE_NAME (psb); |
| /* endaddr non-NULL can't happen here. */ |
| return 1; |
| } |
| } |
| } |
| |
| /* Not in the normal symbol tables, see if the pc is in a known section. |
| If it's not, then give up. This ensures that anything beyond the end |
| of the text seg doesn't appear to be part of the last function in the |
| text segment. */ |
| |
| if (!section) |
| msymbol = NULL; |
| |
| /* Must be in the minimal symbol table. */ |
| if (msymbol == NULL) |
| { |
| /* No available symbol. */ |
| if (name != NULL) |
| *name = 0; |
| if (address != NULL) |
| *address = 0; |
| if (endaddr != NULL) |
| *endaddr = 0; |
| return 0; |
| } |
| |
| cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol); |
| cache_pc_function_name = SYMBOL_LINKAGE_NAME (msymbol); |
| cache_pc_function_section = section; |
| |
| /* If the minimal symbol has a size, use it for the cache. |
| Otherwise use the lesser of the next minimal symbol in the same |
| section, or the end of the section, as the end of the |
| function. */ |
| |
| if (MSYMBOL_SIZE (msymbol) != 0) |
| cache_pc_function_high = cache_pc_function_low + MSYMBOL_SIZE (msymbol); |
| else |
| { |
| /* Step over other symbols at this same address, and symbols in |
| other sections, to find the next symbol in this section with |
| a different address. */ |
| |
| for (i = 1; SYMBOL_LINKAGE_NAME (msymbol + i) != NULL; i++) |
| { |
| if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol) |
| && SYMBOL_OBJ_SECTION (msymbol + i) == SYMBOL_OBJ_SECTION (msymbol)) |
| break; |
| } |
| |
| if (SYMBOL_LINKAGE_NAME (msymbol + i) != NULL |
| && SYMBOL_VALUE_ADDRESS (msymbol + i) < obj_section_endaddr (section)) |
| cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i); |
| else |
| /* We got the start address from the last msymbol in the objfile. |
| So the end address is the end of the section. */ |
| cache_pc_function_high = obj_section_endaddr (section); |
| } |
| |
| return_cached_value: |
| |
| if (address) |
| { |
| if (pc_in_unmapped_range (pc, section)) |
| *address = overlay_unmapped_address (cache_pc_function_low, section); |
| else |
| *address = cache_pc_function_low; |
| } |
| |
| if (name) |
| *name = cache_pc_function_name; |
| |
| if (endaddr) |
| { |
| if (pc_in_unmapped_range (pc, section)) |
| { |
| /* Because the high address is actually beyond the end of |
| the function (and therefore possibly beyond the end of |
| the overlay), we must actually convert (high - 1) and |
| then add one to that. */ |
| |
| *endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1, |
| section); |
| } |
| else |
| *endaddr = cache_pc_function_high; |
| } |
| |
| return 1; |
| } |
| |
| /* Return the innermost stack frame executing inside of BLOCK, |
| or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */ |
| |
| struct frame_info * |
| block_innermost_frame (struct block *block) |
| { |
| struct frame_info *frame; |
| CORE_ADDR start; |
| CORE_ADDR end; |
| CORE_ADDR calling_pc; |
| |
| if (block == NULL) |
| return NULL; |
| |
| start = BLOCK_START (block); |
| end = BLOCK_END (block); |
| |
| frame = get_current_frame (); |
| while (frame != NULL) |
| { |
| calling_pc = get_frame_address_in_block (frame); |
| if (calling_pc >= start && calling_pc < end) |
| return frame; |
| |
| frame = get_prev_frame (frame); |
| } |
| |
| return NULL; |
| } |