5520a790ef
* minsyms.c (lookup_minimal_symbol_text): Remove unused parameter. Remove SOFUN_ADDRESS_MAYBE_MISSING ifdeffed code. * symtab.h (lookup_minimal_symbol_text): Update. * breakpoint.c (create_overlay_event_breakpoint, create_longjmp_breakpoint): Update callers. * ppc-linux-tdep.c (ppc_linux_skip_trampoline_code): Update caller. * symtab.c (find_pc_sect_line): Ditto.
984 lines
33 KiB
C
984 lines
33 KiB
C
/* GDB routines for manipulating the minimal symbol tables.
|
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Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
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2002, 2003
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Free Software Foundation, Inc.
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Contributed by Cygnus Support, using pieces from other GDB modules.
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||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
|
||
(at your option) any later version.
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||
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||
This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
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||
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||
You should have received a copy of the GNU General Public License
|
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along with this program; if not, write to the Free Software
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||
Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* This file contains support routines for creating, manipulating, and
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destroying minimal symbol tables.
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Minimal symbol tables are used to hold some very basic information about
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all defined global symbols (text, data, bss, abs, etc). The only two
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required pieces of information are the symbol's name and the address
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associated with that symbol.
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In many cases, even if a file was compiled with no special options for
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debugging at all, as long as was not stripped it will contain sufficient
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information to build useful minimal symbol tables using this structure.
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Even when a file contains enough debugging information to build a full
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symbol table, these minimal symbols are still useful for quickly mapping
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between names and addresses, and vice versa. They are also sometimes used
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to figure out what full symbol table entries need to be read in. */
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#include "defs.h"
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#include <ctype.h>
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#include "gdb_string.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "demangle.h"
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#include "value.h"
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#include "cp-abi.h"
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/* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE.
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At the end, copy them all into one newly allocated location on an objfile's
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symbol obstack. */
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#define BUNCH_SIZE 127
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struct msym_bunch
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{
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struct msym_bunch *next;
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struct minimal_symbol contents[BUNCH_SIZE];
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};
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/* Bunch currently being filled up.
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The next field points to chain of filled bunches. */
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static struct msym_bunch *msym_bunch;
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/* Number of slots filled in current bunch. */
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static int msym_bunch_index;
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/* Total number of minimal symbols recorded so far for the objfile. */
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static int msym_count;
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/* Compute a hash code based using the same criteria as `strcmp_iw'. */
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unsigned int
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msymbol_hash_iw (const char *string)
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{
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unsigned int hash = 0;
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while (*string && *string != '(')
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{
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while (isspace (*string))
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++string;
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if (*string && *string != '(')
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{
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hash = hash * 67 + *string - 113;
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++string;
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}
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}
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return hash;
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}
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/* Compute a hash code for a string. */
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unsigned int
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msymbol_hash (const char *string)
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{
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unsigned int hash = 0;
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for (; *string; ++string)
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hash = hash * 67 + *string - 113;
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return hash;
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}
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/* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */
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void
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add_minsym_to_hash_table (struct minimal_symbol *sym,
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struct minimal_symbol **table)
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{
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if (sym->hash_next == NULL)
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{
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unsigned int hash
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= msymbol_hash (SYMBOL_LINKAGE_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
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sym->hash_next = table[hash];
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table[hash] = sym;
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}
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}
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/* Add the minimal symbol SYM to an objfile's minsym demangled hash table,
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TABLE. */
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static void
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add_minsym_to_demangled_hash_table (struct minimal_symbol *sym,
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struct minimal_symbol **table)
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{
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if (sym->demangled_hash_next == NULL)
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{
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unsigned int hash = msymbol_hash_iw (SYMBOL_DEMANGLED_NAME (sym)) % MINIMAL_SYMBOL_HASH_SIZE;
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sym->demangled_hash_next = table[hash];
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table[hash] = sym;
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}
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}
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/* Look through all the current minimal symbol tables and find the
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first minimal symbol that matches NAME. If OBJF is non-NULL, limit
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the search to that objfile. If SFILE is non-NULL, the only file-scope
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symbols considered will be from that source file (global symbols are
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still preferred). Returns a pointer to the minimal symbol that
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matches, or NULL if no match is found.
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Note: One instance where there may be duplicate minimal symbols with
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the same name is when the symbol tables for a shared library and the
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symbol tables for an executable contain global symbols with the same
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names (the dynamic linker deals with the duplication). */
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struct minimal_symbol *
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lookup_minimal_symbol (const char *name, const char *sfile,
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struct objfile *objf)
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{
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struct objfile *objfile;
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struct minimal_symbol *msymbol;
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struct minimal_symbol *found_symbol = NULL;
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struct minimal_symbol *found_file_symbol = NULL;
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struct minimal_symbol *trampoline_symbol = NULL;
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unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
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unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
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#ifdef SOFUN_ADDRESS_MAYBE_MISSING
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if (sfile != NULL)
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{
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char *p = strrchr (sfile, '/');
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if (p != NULL)
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sfile = p + 1;
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}
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#endif
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for (objfile = object_files;
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objfile != NULL && found_symbol == NULL;
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objfile = objfile->next)
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{
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if (objf == NULL || objf == objfile)
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{
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/* Do two passes: the first over the ordinary hash table,
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and the second over the demangled hash table. */
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int pass;
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for (pass = 1; pass <= 2 && found_symbol == NULL; pass++)
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{
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/* Select hash list according to pass. */
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if (pass == 1)
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msymbol = objfile->msymbol_hash[hash];
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else
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msymbol = objfile->msymbol_demangled_hash[dem_hash];
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while (msymbol != NULL && found_symbol == NULL)
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{
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/* FIXME: carlton/2003-02-27: This is an unholy
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mixture of linkage names and natural names. If
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you want to test the linkage names with strcmp,
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do that. If you want to test the natural names
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with strcmp_iw, use SYMBOL_MATCHES_NATURAL_NAME. */
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if (strcmp (DEPRECATED_SYMBOL_NAME (msymbol), (name)) == 0
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|| (SYMBOL_DEMANGLED_NAME (msymbol) != NULL
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&& strcmp_iw (SYMBOL_DEMANGLED_NAME (msymbol),
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(name)) == 0))
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{
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switch (MSYMBOL_TYPE (msymbol))
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{
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case mst_file_text:
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case mst_file_data:
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case mst_file_bss:
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#ifdef SOFUN_ADDRESS_MAYBE_MISSING
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if (sfile == NULL || STREQ (msymbol->filename, sfile))
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found_file_symbol = msymbol;
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#else
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/* We have neither the ability nor the need to
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deal with the SFILE parameter. If we find
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more than one symbol, just return the latest
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one (the user can't expect useful behavior in
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that case). */
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found_file_symbol = msymbol;
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#endif
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break;
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case mst_solib_trampoline:
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/* If a trampoline symbol is found, we prefer to
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keep looking for the *real* symbol. If the
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actual symbol is not found, then we'll use the
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trampoline entry. */
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if (trampoline_symbol == NULL)
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trampoline_symbol = msymbol;
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break;
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case mst_unknown:
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default:
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found_symbol = msymbol;
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break;
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}
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}
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/* Find the next symbol on the hash chain. */
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if (pass == 1)
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msymbol = msymbol->hash_next;
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else
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msymbol = msymbol->demangled_hash_next;
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}
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}
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}
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}
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/* External symbols are best. */
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if (found_symbol)
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return found_symbol;
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/* File-local symbols are next best. */
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if (found_file_symbol)
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return found_file_symbol;
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/* Symbols for shared library trampolines are next best. */
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if (trampoline_symbol)
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return trampoline_symbol;
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return NULL;
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}
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/* Look through all the current minimal symbol tables and find the
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first minimal symbol that matches NAME and has text type. If OBJF
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is non-NULL, limit the search to that objfile. Returns a pointer
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to the minimal symbol that matches, or NULL if no match is found.
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This function only searches the mangled (linkage) names. */
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struct minimal_symbol *
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lookup_minimal_symbol_text (const char *name, struct objfile *objf)
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{
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struct objfile *objfile;
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struct minimal_symbol *msymbol;
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struct minimal_symbol *found_symbol = NULL;
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struct minimal_symbol *found_file_symbol = NULL;
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unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
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for (objfile = object_files;
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objfile != NULL && found_symbol == NULL;
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objfile = objfile->next)
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{
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if (objf == NULL || objf == objfile)
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{
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for (msymbol = objfile->msymbol_hash[hash];
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msymbol != NULL && found_symbol == NULL;
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msymbol = msymbol->hash_next)
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{
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if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
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(MSYMBOL_TYPE (msymbol) == mst_text ||
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MSYMBOL_TYPE (msymbol) == mst_file_text))
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{
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switch (MSYMBOL_TYPE (msymbol))
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{
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case mst_file_text:
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found_file_symbol = msymbol;
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break;
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default:
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found_symbol = msymbol;
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break;
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}
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}
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}
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}
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}
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/* External symbols are best. */
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if (found_symbol)
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return found_symbol;
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/* File-local symbols are next best. */
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if (found_file_symbol)
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return found_file_symbol;
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return NULL;
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}
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/* Look through all the current minimal symbol tables and find the
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first minimal symbol that matches NAME and is a solib trampoline.
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If OBJF is non-NULL, limit the search to that objfile. Returns a
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pointer to the minimal symbol that matches, or NULL if no match is
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found.
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This function only searches the mangled (linkage) names. */
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struct minimal_symbol *
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lookup_minimal_symbol_solib_trampoline (const char *name,
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struct objfile *objf)
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{
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struct objfile *objfile;
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struct minimal_symbol *msymbol;
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struct minimal_symbol *found_symbol = NULL;
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unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
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for (objfile = object_files;
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objfile != NULL && found_symbol == NULL;
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objfile = objfile->next)
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{
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if (objf == NULL || objf == objfile)
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{
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for (msymbol = objfile->msymbol_hash[hash];
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msymbol != NULL && found_symbol == NULL;
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msymbol = msymbol->hash_next)
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{
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if (strcmp (SYMBOL_LINKAGE_NAME (msymbol), name) == 0 &&
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MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
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return msymbol;
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}
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}
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}
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return NULL;
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}
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/* Search through the minimal symbol table for each objfile and find
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the symbol whose address is the largest address that is still less
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than or equal to PC, and matches SECTION (if non-null). Returns a
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pointer to the minimal symbol if such a symbol is found, or NULL if
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PC is not in a suitable range. Note that we need to look through
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ALL the minimal symbol tables before deciding on the symbol that
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comes closest to the specified PC. This is because objfiles can
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overlap, for example objfile A has .text at 0x100 and .data at
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0x40000 and objfile B has .text at 0x234 and .data at 0x40048. */
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struct minimal_symbol *
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lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, asection *section)
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{
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int lo;
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int hi;
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int new;
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struct objfile *objfile;
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struct minimal_symbol *msymbol;
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struct minimal_symbol *best_symbol = NULL;
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struct obj_section *pc_section;
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/* pc has to be in a known section. This ensures that anything beyond
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the end of the last segment doesn't appear to be part of the last
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function in the last segment. */
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pc_section = find_pc_section (pc);
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if (pc_section == NULL)
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return NULL;
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/* If no section was specified, then just make sure that the PC is in
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the same section as the minimal symbol we find. */
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if (section == NULL)
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section = pc_section->the_bfd_section;
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/* FIXME drow/2003-07-19: Should we also check that PC is in SECTION
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if we were passed a non-NULL SECTION argument? */
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for (objfile = object_files;
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objfile != NULL;
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objfile = objfile->next)
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{
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/* If this objfile has a minimal symbol table, go search it using
|
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a binary search. Note that a minimal symbol table always consists
|
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of at least two symbols, a "real" symbol and the terminating
|
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"null symbol". If there are no real symbols, then there is no
|
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minimal symbol table at all. */
|
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if (objfile->minimal_symbol_count > 0)
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{
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msymbol = objfile->msymbols;
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lo = 0;
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hi = objfile->minimal_symbol_count - 1;
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/* This code assumes that the minimal symbols are sorted by
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ascending address values. If the pc value is greater than or
|
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equal to the first symbol's address, then some symbol in this
|
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minimal symbol table is a suitable candidate for being the
|
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"best" symbol. This includes the last real symbol, for cases
|
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where the pc value is larger than any address in this vector.
|
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|
||
By iterating until the address associated with the current
|
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hi index (the endpoint of the test interval) is less than
|
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or equal to the desired pc value, we accomplish two things:
|
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(1) the case where the pc value is larger than any minimal
|
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symbol address is trivially solved, (2) the address associated
|
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with the hi index is always the one we want when the interation
|
||
terminates. In essence, we are iterating the test interval
|
||
down until the pc value is pushed out of it from the high end.
|
||
|
||
Warning: this code is trickier than it would appear at first. */
|
||
|
||
/* Should also require that pc is <= end of objfile. FIXME! */
|
||
if (pc >= SYMBOL_VALUE_ADDRESS (&msymbol[lo]))
|
||
{
|
||
while (SYMBOL_VALUE_ADDRESS (&msymbol[hi]) > pc)
|
||
{
|
||
/* pc is still strictly less than highest address */
|
||
/* Note "new" will always be >= lo */
|
||
new = (lo + hi) / 2;
|
||
if ((SYMBOL_VALUE_ADDRESS (&msymbol[new]) >= pc) ||
|
||
(lo == new))
|
||
{
|
||
hi = new;
|
||
}
|
||
else
|
||
{
|
||
lo = new;
|
||
}
|
||
}
|
||
|
||
/* If we have multiple symbols at the same address, we want
|
||
hi to point to the last one. That way we can find the
|
||
right symbol if it has an index greater than hi. */
|
||
while (hi < objfile->minimal_symbol_count - 1
|
||
&& (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
|
||
== SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1])))
|
||
hi++;
|
||
|
||
/* The minimal symbol indexed by hi now is the best one in this
|
||
objfile's minimal symbol table. See if it is the best one
|
||
overall. */
|
||
|
||
/* Skip any absolute symbols. This is apparently what adb
|
||
and dbx do, and is needed for the CM-5. There are two
|
||
known possible problems: (1) on ELF, apparently end, edata,
|
||
etc. are absolute. Not sure ignoring them here is a big
|
||
deal, but if we want to use them, the fix would go in
|
||
elfread.c. (2) I think shared library entry points on the
|
||
NeXT are absolute. If we want special handling for this
|
||
it probably should be triggered by a special
|
||
mst_abs_or_lib or some such. */
|
||
while (hi >= 0
|
||
&& msymbol[hi].type == mst_abs)
|
||
--hi;
|
||
|
||
/* If "section" specified, skip any symbol from wrong section */
|
||
/* This is the new code that distinguishes it from the old function */
|
||
if (section)
|
||
while (hi >= 0
|
||
/* Some types of debug info, such as COFF,
|
||
don't fill the bfd_section member, so don't
|
||
throw away symbols on those platforms. */
|
||
&& SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
|
||
&& SYMBOL_BFD_SECTION (&msymbol[hi]) != section)
|
||
--hi;
|
||
|
||
if (hi >= 0
|
||
&& ((best_symbol == NULL) ||
|
||
(SYMBOL_VALUE_ADDRESS (best_symbol) <
|
||
SYMBOL_VALUE_ADDRESS (&msymbol[hi]))))
|
||
{
|
||
best_symbol = &msymbol[hi];
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return (best_symbol);
|
||
}
|
||
|
||
/* Backward compatibility: search through the minimal symbol table
|
||
for a matching PC (no section given) */
|
||
|
||
struct minimal_symbol *
|
||
lookup_minimal_symbol_by_pc (CORE_ADDR pc)
|
||
{
|
||
return lookup_minimal_symbol_by_pc_section (pc, find_pc_mapped_section (pc));
|
||
}
|
||
|
||
|
||
/* Return leading symbol character for a BFD. If BFD is NULL,
|
||
return the leading symbol character from the main objfile. */
|
||
|
||
static int get_symbol_leading_char (bfd *);
|
||
|
||
static int
|
||
get_symbol_leading_char (bfd *abfd)
|
||
{
|
||
if (abfd != NULL)
|
||
return bfd_get_symbol_leading_char (abfd);
|
||
if (symfile_objfile != NULL && symfile_objfile->obfd != NULL)
|
||
return bfd_get_symbol_leading_char (symfile_objfile->obfd);
|
||
return 0;
|
||
}
|
||
|
||
/* Prepare to start collecting minimal symbols. Note that presetting
|
||
msym_bunch_index to BUNCH_SIZE causes the first call to save a minimal
|
||
symbol to allocate the memory for the first bunch. */
|
||
|
||
void
|
||
init_minimal_symbol_collection (void)
|
||
{
|
||
msym_count = 0;
|
||
msym_bunch = NULL;
|
||
msym_bunch_index = BUNCH_SIZE;
|
||
}
|
||
|
||
void
|
||
prim_record_minimal_symbol (const char *name, CORE_ADDR address,
|
||
enum minimal_symbol_type ms_type,
|
||
struct objfile *objfile)
|
||
{
|
||
int section;
|
||
|
||
switch (ms_type)
|
||
{
|
||
case mst_text:
|
||
case mst_file_text:
|
||
case mst_solib_trampoline:
|
||
section = SECT_OFF_TEXT (objfile);
|
||
break;
|
||
case mst_data:
|
||
case mst_file_data:
|
||
section = SECT_OFF_DATA (objfile);
|
||
break;
|
||
case mst_bss:
|
||
case mst_file_bss:
|
||
section = SECT_OFF_BSS (objfile);
|
||
break;
|
||
default:
|
||
section = -1;
|
||
}
|
||
|
||
prim_record_minimal_symbol_and_info (name, address, ms_type,
|
||
NULL, section, NULL, objfile);
|
||
}
|
||
|
||
/* Record a minimal symbol in the msym bunches. Returns the symbol
|
||
newly created. */
|
||
|
||
struct minimal_symbol *
|
||
prim_record_minimal_symbol_and_info (const char *name, CORE_ADDR address,
|
||
enum minimal_symbol_type ms_type,
|
||
char *info, int section,
|
||
asection *bfd_section,
|
||
struct objfile *objfile)
|
||
{
|
||
struct msym_bunch *new;
|
||
struct minimal_symbol *msymbol;
|
||
|
||
if (ms_type == mst_file_text)
|
||
{
|
||
/* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
|
||
the minimal symbols, because if there is also another symbol
|
||
at the same address (e.g. the first function of the file),
|
||
lookup_minimal_symbol_by_pc would have no way of getting the
|
||
right one. */
|
||
if (name[0] == 'g'
|
||
&& (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
|
||
|| strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
|
||
return (NULL);
|
||
|
||
{
|
||
const char *tempstring = name;
|
||
if (tempstring[0] == get_symbol_leading_char (objfile->obfd))
|
||
++tempstring;
|
||
if (STREQN (tempstring, "__gnu_compiled", 14))
|
||
return (NULL);
|
||
}
|
||
}
|
||
|
||
if (msym_bunch_index == BUNCH_SIZE)
|
||
{
|
||
new = (struct msym_bunch *) xmalloc (sizeof (struct msym_bunch));
|
||
msym_bunch_index = 0;
|
||
new->next = msym_bunch;
|
||
msym_bunch = new;
|
||
}
|
||
msymbol = &msym_bunch->contents[msym_bunch_index];
|
||
SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown);
|
||
SYMBOL_LANGUAGE (msymbol) = language_auto;
|
||
SYMBOL_SET_NAMES (msymbol, (char *)name, strlen (name), objfile);
|
||
|
||
SYMBOL_VALUE_ADDRESS (msymbol) = address;
|
||
SYMBOL_SECTION (msymbol) = section;
|
||
SYMBOL_BFD_SECTION (msymbol) = bfd_section;
|
||
|
||
MSYMBOL_TYPE (msymbol) = ms_type;
|
||
/* FIXME: This info, if it remains, needs its own field. */
|
||
MSYMBOL_INFO (msymbol) = info; /* FIXME! */
|
||
|
||
/* The hash pointers must be cleared! If they're not,
|
||
add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
|
||
msymbol->hash_next = NULL;
|
||
msymbol->demangled_hash_next = NULL;
|
||
|
||
msym_bunch_index++;
|
||
msym_count++;
|
||
OBJSTAT (objfile, n_minsyms++);
|
||
return msymbol;
|
||
}
|
||
|
||
/* Compare two minimal symbols by address and return a signed result based
|
||
on unsigned comparisons, so that we sort into unsigned numeric order.
|
||
Within groups with the same address, sort by name. */
|
||
|
||
static int
|
||
compare_minimal_symbols (const void *fn1p, const void *fn2p)
|
||
{
|
||
const struct minimal_symbol *fn1;
|
||
const struct minimal_symbol *fn2;
|
||
|
||
fn1 = (const struct minimal_symbol *) fn1p;
|
||
fn2 = (const struct minimal_symbol *) fn2p;
|
||
|
||
if (SYMBOL_VALUE_ADDRESS (fn1) < SYMBOL_VALUE_ADDRESS (fn2))
|
||
{
|
||
return (-1); /* addr 1 is less than addr 2 */
|
||
}
|
||
else if (SYMBOL_VALUE_ADDRESS (fn1) > SYMBOL_VALUE_ADDRESS (fn2))
|
||
{
|
||
return (1); /* addr 1 is greater than addr 2 */
|
||
}
|
||
else
|
||
/* addrs are equal: sort by name */
|
||
{
|
||
char *name1 = SYMBOL_LINKAGE_NAME (fn1);
|
||
char *name2 = SYMBOL_LINKAGE_NAME (fn2);
|
||
|
||
if (name1 && name2) /* both have names */
|
||
return strcmp (name1, name2);
|
||
else if (name2)
|
||
return 1; /* fn1 has no name, so it is "less" */
|
||
else if (name1) /* fn2 has no name, so it is "less" */
|
||
return -1;
|
||
else
|
||
return (0); /* neither has a name, so they're equal. */
|
||
}
|
||
}
|
||
|
||
/* Discard the currently collected minimal symbols, if any. If we wish
|
||
to save them for later use, we must have already copied them somewhere
|
||
else before calling this function.
|
||
|
||
FIXME: We could allocate the minimal symbol bunches on their own
|
||
obstack and then simply blow the obstack away when we are done with
|
||
it. Is it worth the extra trouble though? */
|
||
|
||
static void
|
||
do_discard_minimal_symbols_cleanup (void *arg)
|
||
{
|
||
struct msym_bunch *next;
|
||
|
||
while (msym_bunch != NULL)
|
||
{
|
||
next = msym_bunch->next;
|
||
xfree (msym_bunch);
|
||
msym_bunch = next;
|
||
}
|
||
}
|
||
|
||
struct cleanup *
|
||
make_cleanup_discard_minimal_symbols (void)
|
||
{
|
||
return make_cleanup (do_discard_minimal_symbols_cleanup, 0);
|
||
}
|
||
|
||
|
||
|
||
/* Compact duplicate entries out of a minimal symbol table by walking
|
||
through the table and compacting out entries with duplicate addresses
|
||
and matching names. Return the number of entries remaining.
|
||
|
||
On entry, the table resides between msymbol[0] and msymbol[mcount].
|
||
On exit, it resides between msymbol[0] and msymbol[result_count].
|
||
|
||
When files contain multiple sources of symbol information, it is
|
||
possible for the minimal symbol table to contain many duplicate entries.
|
||
As an example, SVR4 systems use ELF formatted object files, which
|
||
usually contain at least two different types of symbol tables (a
|
||
standard ELF one and a smaller dynamic linking table), as well as
|
||
DWARF debugging information for files compiled with -g.
|
||
|
||
Without compacting, the minimal symbol table for gdb itself contains
|
||
over a 1000 duplicates, about a third of the total table size. Aside
|
||
from the potential trap of not noticing that two successive entries
|
||
identify the same location, this duplication impacts the time required
|
||
to linearly scan the table, which is done in a number of places. So we
|
||
just do one linear scan here and toss out the duplicates.
|
||
|
||
Note that we are not concerned here about recovering the space that
|
||
is potentially freed up, because the strings themselves are allocated
|
||
on the symbol_obstack, and will get automatically freed when the symbol
|
||
table is freed. The caller can free up the unused minimal symbols at
|
||
the end of the compacted region if their allocation strategy allows it.
|
||
|
||
Also note we only go up to the next to last entry within the loop
|
||
and then copy the last entry explicitly after the loop terminates.
|
||
|
||
Since the different sources of information for each symbol may
|
||
have different levels of "completeness", we may have duplicates
|
||
that have one entry with type "mst_unknown" and the other with a
|
||
known type. So if the one we are leaving alone has type mst_unknown,
|
||
overwrite its type with the type from the one we are compacting out. */
|
||
|
||
static int
|
||
compact_minimal_symbols (struct minimal_symbol *msymbol, int mcount,
|
||
struct objfile *objfile)
|
||
{
|
||
struct minimal_symbol *copyfrom;
|
||
struct minimal_symbol *copyto;
|
||
|
||
if (mcount > 0)
|
||
{
|
||
copyfrom = copyto = msymbol;
|
||
while (copyfrom < msymbol + mcount - 1)
|
||
{
|
||
if (SYMBOL_VALUE_ADDRESS (copyfrom) ==
|
||
SYMBOL_VALUE_ADDRESS ((copyfrom + 1)) &&
|
||
(STREQ (SYMBOL_LINKAGE_NAME (copyfrom),
|
||
SYMBOL_LINKAGE_NAME ((copyfrom + 1)))))
|
||
{
|
||
if (MSYMBOL_TYPE ((copyfrom + 1)) == mst_unknown)
|
||
{
|
||
MSYMBOL_TYPE ((copyfrom + 1)) = MSYMBOL_TYPE (copyfrom);
|
||
}
|
||
copyfrom++;
|
||
}
|
||
else
|
||
*copyto++ = *copyfrom++;
|
||
}
|
||
*copyto++ = *copyfrom++;
|
||
mcount = copyto - msymbol;
|
||
}
|
||
return (mcount);
|
||
}
|
||
|
||
/* Build (or rebuild) the minimal symbol hash tables. This is necessary
|
||
after compacting or sorting the table since the entries move around
|
||
thus causing the internal minimal_symbol pointers to become jumbled. */
|
||
|
||
static void
|
||
build_minimal_symbol_hash_tables (struct objfile *objfile)
|
||
{
|
||
int i;
|
||
struct minimal_symbol *msym;
|
||
|
||
/* Clear the hash tables. */
|
||
for (i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++)
|
||
{
|
||
objfile->msymbol_hash[i] = 0;
|
||
objfile->msymbol_demangled_hash[i] = 0;
|
||
}
|
||
|
||
/* Now, (re)insert the actual entries. */
|
||
for (i = objfile->minimal_symbol_count, msym = objfile->msymbols;
|
||
i > 0;
|
||
i--, msym++)
|
||
{
|
||
msym->hash_next = 0;
|
||
add_minsym_to_hash_table (msym, objfile->msymbol_hash);
|
||
|
||
msym->demangled_hash_next = 0;
|
||
if (SYMBOL_DEMANGLED_NAME (msym) != NULL)
|
||
add_minsym_to_demangled_hash_table (msym,
|
||
objfile->msymbol_demangled_hash);
|
||
}
|
||
}
|
||
|
||
/* Add the minimal symbols in the existing bunches to the objfile's official
|
||
minimal symbol table. In most cases there is no minimal symbol table yet
|
||
for this objfile, and the existing bunches are used to create one. Once
|
||
in a while (for shared libraries for example), we add symbols (e.g. common
|
||
symbols) to an existing objfile.
|
||
|
||
Because of the way minimal symbols are collected, we generally have no way
|
||
of knowing what source language applies to any particular minimal symbol.
|
||
Specifically, we have no way of knowing if the minimal symbol comes from a
|
||
C++ compilation unit or not. So for the sake of supporting cached
|
||
demangled C++ names, we have no choice but to try and demangle each new one
|
||
that comes in. If the demangling succeeds, then we assume it is a C++
|
||
symbol and set the symbol's language and demangled name fields
|
||
appropriately. Note that in order to avoid unnecessary demanglings, and
|
||
allocating obstack space that subsequently can't be freed for the demangled
|
||
names, we mark all newly added symbols with language_auto. After
|
||
compaction of the minimal symbols, we go back and scan the entire minimal
|
||
symbol table looking for these new symbols. For each new symbol we attempt
|
||
to demangle it, and if successful, record it as a language_cplus symbol
|
||
and cache the demangled form on the symbol obstack. Symbols which don't
|
||
demangle are marked as language_unknown symbols, which inhibits future
|
||
attempts to demangle them if we later add more minimal symbols. */
|
||
|
||
void
|
||
install_minimal_symbols (struct objfile *objfile)
|
||
{
|
||
int bindex;
|
||
int mcount;
|
||
struct msym_bunch *bunch;
|
||
struct minimal_symbol *msymbols;
|
||
int alloc_count;
|
||
char leading_char;
|
||
|
||
if (msym_count > 0)
|
||
{
|
||
/* Allocate enough space in the obstack, into which we will gather the
|
||
bunches of new and existing minimal symbols, sort them, and then
|
||
compact out the duplicate entries. Once we have a final table,
|
||
we will give back the excess space. */
|
||
|
||
alloc_count = msym_count + objfile->minimal_symbol_count + 1;
|
||
obstack_blank (&objfile->symbol_obstack,
|
||
alloc_count * sizeof (struct minimal_symbol));
|
||
msymbols = (struct minimal_symbol *)
|
||
obstack_base (&objfile->symbol_obstack);
|
||
|
||
/* Copy in the existing minimal symbols, if there are any. */
|
||
|
||
if (objfile->minimal_symbol_count)
|
||
memcpy ((char *) msymbols, (char *) objfile->msymbols,
|
||
objfile->minimal_symbol_count * sizeof (struct minimal_symbol));
|
||
|
||
/* Walk through the list of minimal symbol bunches, adding each symbol
|
||
to the new contiguous array of symbols. Note that we start with the
|
||
current, possibly partially filled bunch (thus we use the current
|
||
msym_bunch_index for the first bunch we copy over), and thereafter
|
||
each bunch is full. */
|
||
|
||
mcount = objfile->minimal_symbol_count;
|
||
leading_char = get_symbol_leading_char (objfile->obfd);
|
||
|
||
for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
|
||
{
|
||
for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
|
||
{
|
||
msymbols[mcount] = bunch->contents[bindex];
|
||
if (SYMBOL_LINKAGE_NAME (&msymbols[mcount])[0] == leading_char)
|
||
{
|
||
SYMBOL_LINKAGE_NAME (&msymbols[mcount])++;
|
||
}
|
||
}
|
||
msym_bunch_index = BUNCH_SIZE;
|
||
}
|
||
|
||
/* Sort the minimal symbols by address. */
|
||
|
||
qsort (msymbols, mcount, sizeof (struct minimal_symbol),
|
||
compare_minimal_symbols);
|
||
|
||
/* Compact out any duplicates, and free up whatever space we are
|
||
no longer using. */
|
||
|
||
mcount = compact_minimal_symbols (msymbols, mcount, objfile);
|
||
|
||
obstack_blank (&objfile->symbol_obstack,
|
||
(mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
|
||
msymbols = (struct minimal_symbol *)
|
||
obstack_finish (&objfile->symbol_obstack);
|
||
|
||
/* We also terminate the minimal symbol table with a "null symbol",
|
||
which is *not* included in the size of the table. This makes it
|
||
easier to find the end of the table when we are handed a pointer
|
||
to some symbol in the middle of it. Zero out the fields in the
|
||
"null symbol" allocated at the end of the array. Note that the
|
||
symbol count does *not* include this null symbol, which is why it
|
||
is indexed by mcount and not mcount-1. */
|
||
|
||
SYMBOL_LINKAGE_NAME (&msymbols[mcount]) = NULL;
|
||
SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0;
|
||
MSYMBOL_INFO (&msymbols[mcount]) = NULL;
|
||
MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown;
|
||
SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown);
|
||
|
||
/* Attach the minimal symbol table to the specified objfile.
|
||
The strings themselves are also located in the symbol_obstack
|
||
of this objfile. */
|
||
|
||
objfile->minimal_symbol_count = mcount;
|
||
objfile->msymbols = msymbols;
|
||
|
||
/* Try to guess the appropriate C++ ABI by looking at the names
|
||
of the minimal symbols in the table. */
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < mcount; i++)
|
||
{
|
||
/* If a symbol's name starts with _Z and was successfully
|
||
demangled, then we can assume we've found a GNU v3 symbol.
|
||
For now we set the C++ ABI globally; if the user is
|
||
mixing ABIs then the user will need to "set cp-abi"
|
||
manually. */
|
||
const char *name = SYMBOL_LINKAGE_NAME (&objfile->msymbols[i]);
|
||
if (name[0] == '_' && name[1] == 'Z'
|
||
&& SYMBOL_DEMANGLED_NAME (&objfile->msymbols[i]) != NULL)
|
||
{
|
||
set_cp_abi_as_auto_default ("gnu-v3");
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Now build the hash tables; we can't do this incrementally
|
||
at an earlier point since we weren't finished with the obstack
|
||
yet. (And if the msymbol obstack gets moved, all the internal
|
||
pointers to other msymbols need to be adjusted.) */
|
||
build_minimal_symbol_hash_tables (objfile);
|
||
}
|
||
}
|
||
|
||
/* Sort all the minimal symbols in OBJFILE. */
|
||
|
||
void
|
||
msymbols_sort (struct objfile *objfile)
|
||
{
|
||
qsort (objfile->msymbols, objfile->minimal_symbol_count,
|
||
sizeof (struct minimal_symbol), compare_minimal_symbols);
|
||
build_minimal_symbol_hash_tables (objfile);
|
||
}
|
||
|
||
/* Check if PC is in a shared library trampoline code stub.
|
||
Return minimal symbol for the trampoline entry or NULL if PC is not
|
||
in a trampoline code stub. */
|
||
|
||
struct minimal_symbol *
|
||
lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc)
|
||
{
|
||
struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
|
||
|
||
if (msymbol != NULL && MSYMBOL_TYPE (msymbol) == mst_solib_trampoline)
|
||
return msymbol;
|
||
return NULL;
|
||
}
|
||
|
||
/* If PC is in a shared library trampoline code stub, return the
|
||
address of the `real' function belonging to the stub.
|
||
Return 0 if PC is not in a trampoline code stub or if the real
|
||
function is not found in the minimal symbol table.
|
||
|
||
We may fail to find the right function if a function with the
|
||
same name is defined in more than one shared library, but this
|
||
is considered bad programming style. We could return 0 if we find
|
||
a duplicate function in case this matters someday. */
|
||
|
||
CORE_ADDR
|
||
find_solib_trampoline_target (CORE_ADDR pc)
|
||
{
|
||
struct objfile *objfile;
|
||
struct minimal_symbol *msymbol;
|
||
struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc);
|
||
|
||
if (tsymbol != NULL)
|
||
{
|
||
ALL_MSYMBOLS (objfile, msymbol)
|
||
{
|
||
if (MSYMBOL_TYPE (msymbol) == mst_text
|
||
&& STREQ (SYMBOL_LINKAGE_NAME (msymbol),
|
||
SYMBOL_LINKAGE_NAME (tsymbol)))
|
||
return SYMBOL_VALUE_ADDRESS (msymbol);
|
||
}
|
||
}
|
||
return 0;
|
||
}
|