| /* Get info from stack frames; convert between frames, blocks, |
| functions and pc values. |
| |
| Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, |
| 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
| 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., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "symtab.h" |
| #include "bfd.h" |
| #include "objfiles.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "value.h" /* for read_register */ |
| #include "target.h" /* for target_has_stack */ |
| #include "inferior.h" /* for read_pc */ |
| #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); |
| |
| /* Test whether PC is in the range of addresses that corresponds to |
| the "main" function. */ |
| |
| int |
| inside_main_func (CORE_ADDR pc) |
| { |
| struct minimal_symbol *msymbol; |
| |
| if (symfile_objfile == 0) |
| return 0; |
| |
| msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile); |
| |
| /* If the address range hasn't been set up at symbol reading time, |
| set it up now. */ |
| |
| if (msymbol != NULL |
| && symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC |
| && symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC) |
| { |
| /* brobecker/2003-10-10: We used to rely on lookup_symbol() to |
| search the symbol associated to the "main" function. |
| Unfortunately, lookup_symbol() uses the current-language |
| la_lookup_symbol_nonlocal function to do the global symbol |
| search. Depending on the language, this can introduce |
| certain side-effects, because certain languages, for instance |
| Ada, may find more than one match. Therefore we prefer to |
| search the "main" function symbol using its address rather |
| than its name. */ |
| struct symbol *mainsym = |
| find_pc_function (SYMBOL_VALUE_ADDRESS (msymbol)); |
| |
| if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK) |
| { |
| symfile_objfile->ei.main_func_lowpc = |
| BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym)); |
| symfile_objfile->ei.main_func_highpc = |
| BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym)); |
| } |
| } |
| |
| /* Not in the normal symbol tables, see if "main" is in the partial |
| symbol table. If it's not, then give up. */ |
| if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_text) |
| { |
| CORE_ADDR maddr = SYMBOL_VALUE_ADDRESS (msymbol); |
| asection *msect = SYMBOL_BFD_SECTION (msymbol); |
| struct obj_section *osect = find_pc_sect_section (maddr, msect); |
| |
| if (osect != NULL) |
| { |
| int i; |
| |
| /* 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) != maddr |
| && SYMBOL_BFD_SECTION (msymbol + i) == msect) |
| break; |
| } |
| |
| symfile_objfile->ei.main_func_lowpc = maddr; |
| |
| /* 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 (SYMBOL_LINKAGE_NAME (msymbol + i) != NULL |
| && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr) |
| symfile_objfile->ei.main_func_highpc = |
| 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. */ |
| symfile_objfile->ei.main_func_highpc = osect->endaddr; |
| } |
| } |
| |
| return (symfile_objfile->ei.main_func_lowpc <= pc |
| && symfile_objfile->ei.main_func_highpc > pc); |
| } |
| |
| /* Test whether THIS_FRAME is inside the process entry point function. */ |
| |
| int |
| inside_entry_func (struct frame_info *this_frame) |
| { |
| return (get_frame_func (this_frame) == entry_point_address ()); |
| } |
| |
| /* Return nonzero if the function for this frame lacks a prologue. |
| Many machines can define DEPRECATED_FRAMELESS_FUNCTION_INVOCATION |
| to just call this function. */ |
| |
| int |
| legacy_frameless_look_for_prologue (struct frame_info *frame) |
| { |
| CORE_ADDR func_start; |
| |
| func_start = get_frame_func (frame); |
| if (func_start) |
| { |
| func_start += DEPRECATED_FUNCTION_START_OFFSET; |
| /* NOTE: cagney/2004-02-09: Eliminated per-architecture |
| PROLOGUE_FRAMELESS_P call as architectures with custom |
| implementations had all been deleted. Eventually even this |
| function can go - GDB no longer tries to differentiate |
| between framed, frameless and stackless functions. They are |
| all now considered equally evil :-^. */ |
| /* If skipping the prologue ends up skips nothing, there must be |
| no prologue and hence no code creating a frame. There for |
| the function is "frameless" :-/. */ |
| return func_start == SKIP_PROLOGUE (func_start); |
| } |
| else if (get_frame_pc (frame) == 0) |
| /* A frame with a zero PC is usually created by dereferencing a |
| NULL function pointer, normally causing an immediate core dump |
| of the inferior. Mark function as frameless, as the inferior |
| has no chance of setting up a stack frame. */ |
| return 1; |
| else |
| /* If we can't find the start of the function, we don't really |
| know whether the function is frameless, but we should be able |
| to get a reasonable (i.e. best we can do under the |
| circumstances) backtrace by saying that it isn't. */ |
| return 0; |
| } |
| |
| /* 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_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_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 bfd_section *section) |
| { |
| struct block *b = block_for_pc_sect (pc, section); |
| if (b == 0) |
| return 0; |
| return block_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 bfd_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 bfd_section *section; |
| struct partial_symtab *pst; |
| struct symbol *f; |
| struct minimal_symbol *msymbol; |
| struct partial_symbol *psb; |
| struct obj_section *osect; |
| 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) |
| { |
| struct obj_section *obj_section = find_pc_section (pc); |
| if (obj_section == NULL) |
| section = NULL; |
| else |
| section = obj_section->the_bfd_section; |
| } |
| |
| 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 = DEPRECATED_SYMBOL_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 = DEPRECATED_SYMBOL_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. */ |
| |
| osect = find_pc_sect_section (mapped_pc, section); |
| |
| if (!osect) |
| 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 = DEPRECATED_SYMBOL_NAME (msymbol); |
| cache_pc_function_section = section; |
| |
| /* Use the lesser of the next minimal symbol in the same section, or |
| the end of the section, as the end of the function. */ |
| |
| /* 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; DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL; i++) |
| { |
| if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol) |
| && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol)) |
| break; |
| } |
| |
| if (DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL |
| && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr) |
| 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 = osect->endaddr; |
| |
| 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 = NULL; |
| while (1) |
| { |
| frame = get_prev_frame (frame); |
| if (frame == NULL) |
| return NULL; |
| calling_pc = get_frame_address_in_block (frame); |
| if (calling_pc >= start && calling_pc < end) |
| return frame; |
| } |
| } |
| |
| /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK |
| below is for infrun.c, which may give the macro a pc without that |
| subtracted out. */ |
| |
| /* Returns true for a user frame or a call_function_by_hand dummy |
| frame, and false for the CRT0 start-up frame. Purpose is to |
| terminate backtrace. */ |
| |
| int |
| legacy_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi) |
| { |
| /* Don't prune CALL_DUMMY frames. */ |
| if (deprecated_pc_in_call_dummy (get_frame_pc (fi))) |
| return 1; |
| |
| /* If the new frame pointer is zero, then it isn't valid. */ |
| if (fp == 0) |
| return 0; |
| |
| /* If the new frame would be inside (younger than) the previous frame, |
| then it isn't valid. */ |
| if (INNER_THAN (fp, get_frame_base (fi))) |
| return 0; |
| |
| /* If the architecture has a custom DEPRECATED_FRAME_CHAIN_VALID, |
| call it now. */ |
| if (DEPRECATED_FRAME_CHAIN_VALID_P ()) |
| return DEPRECATED_FRAME_CHAIN_VALID (fp, fi); |
| |
| /* If we're already inside the entry function for the main objfile, |
| then it isn't valid. */ |
| if (inside_entry_func (fi)) |
| return 0; |
| |
| return 1; |
| } |