| /* GDB routines for manipulating the minimal symbol tables. |
| Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 |
| Free Software Foundation, Inc. |
| Contributed by Cygnus Support, using pieces from other GDB modules. |
| |
| 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. */ |
| |
| |
| /* This file contains support routines for creating, manipulating, and |
| destroying minimal symbol tables. |
| |
| Minimal symbol tables are used to hold some very basic information about |
| all defined global symbols (text, data, bss, abs, etc). The only two |
| required pieces of information are the symbol's name and the address |
| associated with that symbol. |
| |
| In many cases, even if a file was compiled with no special options for |
| debugging at all, as long as was not stripped it will contain sufficient |
| information to build useful minimal symbol tables using this structure. |
| |
| Even when a file contains enough debugging information to build a full |
| symbol table, these minimal symbols are still useful for quickly mapping |
| between names and addresses, and vice versa. They are also sometimes used |
| to figure out what full symbol table entries need to be read in. */ |
| |
| |
| #include "defs.h" |
| #include <ctype.h> |
| #include "gdb_string.h" |
| #include "symtab.h" |
| #include "bfd.h" |
| #include "symfile.h" |
| #include "objfiles.h" |
| #include "demangle.h" |
| |
| /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. |
| At the end, copy them all into one newly allocated location on an objfile's |
| symbol obstack. */ |
| |
| #define BUNCH_SIZE 127 |
| |
| struct msym_bunch |
| { |
| struct msym_bunch *next; |
| struct minimal_symbol contents[BUNCH_SIZE]; |
| }; |
| |
| /* Bunch currently being filled up. |
| The next field points to chain of filled bunches. */ |
| |
| static struct msym_bunch *msym_bunch; |
| |
| /* Number of slots filled in current bunch. */ |
| |
| static int msym_bunch_index; |
| |
| /* Total number of minimal symbols recorded so far for the objfile. */ |
| |
| static int msym_count; |
| |
| /* Prototypes for local functions. */ |
| |
| static int compare_minimal_symbols (const void *, const void *); |
| |
| static int |
| compact_minimal_symbols (struct minimal_symbol *, int, struct objfile *); |
| |
| static void add_minsym_to_demangled_hash_table (struct minimal_symbol *sym, |
| struct minimal_symbol **table); |
| |
| /* Compute a hash code based using the same criteria as `strcmp_iw'. */ |
| |
| unsigned int |
| msymbol_hash_iw (const char *string) |
| { |
| unsigned int hash = 0; |
| while (*string && *string != '(') |
| { |
| while (isspace (*string)) |
| ++string; |
| if (*string && *string != '(') |
| hash = (31 * hash) + *string; |
| ++string; |
| } |
| return hash % MINIMAL_SYMBOL_HASH_SIZE; |
| } |
| |
| /* Compute a hash code for a string. */ |
| |
| unsigned int |
| msymbol_hash (const char *string) |
| { |
| unsigned int hash = 0; |
| for (; *string; ++string) |
| hash = (31 * hash) + *string; |
| return hash % MINIMAL_SYMBOL_HASH_SIZE; |
| } |
| |
| /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */ |
| void |
| add_minsym_to_hash_table (struct minimal_symbol *sym, |
| struct minimal_symbol **table) |
| { |
| if (sym->hash_next == NULL) |
| { |
| unsigned int hash = msymbol_hash (SYMBOL_NAME (sym)); |
| sym->hash_next = table[hash]; |
| table[hash] = sym; |
| } |
| } |
| |
| /* Add the minimal symbol SYM to an objfile's minsym demangled hash table, |
| TABLE. */ |
| static void |
| add_minsym_to_demangled_hash_table (struct minimal_symbol *sym, |
| struct minimal_symbol **table) |
| { |
| if (sym->demangled_hash_next == NULL) |
| { |
| unsigned int hash = msymbol_hash_iw (SYMBOL_DEMANGLED_NAME (sym)); |
| sym->demangled_hash_next = table[hash]; |
| table[hash] = sym; |
| } |
| } |
| |
| |
| /* Look through all the current minimal symbol tables and find the |
| first minimal symbol that matches NAME. If OBJF is non-NULL, limit |
| the search to that objfile. If SFILE is non-NULL, limit the search |
| to that source file. Returns a pointer to the minimal symbol that |
| matches, or NULL if no match is found. |
| |
| Note: One instance where there may be duplicate minimal symbols with |
| the same name is when the symbol tables for a shared library and the |
| symbol tables for an executable contain global symbols with the same |
| names (the dynamic linker deals with the duplication). */ |
| |
| struct minimal_symbol * |
| lookup_minimal_symbol (register const char *name, const char *sfile, |
| struct objfile *objf) |
| { |
| struct objfile *objfile; |
| struct minimal_symbol *msymbol; |
| struct minimal_symbol *found_symbol = NULL; |
| struct minimal_symbol *found_file_symbol = NULL; |
| struct minimal_symbol *trampoline_symbol = NULL; |
| |
| unsigned int hash = msymbol_hash (name); |
| unsigned int dem_hash = msymbol_hash_iw (name); |
| |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| if (sfile != NULL) |
| { |
| char *p = strrchr (sfile, '/'); |
| if (p != NULL) |
| sfile = p + 1; |
| } |
| #endif |
| |
| for (objfile = object_files; |
| objfile != NULL && found_symbol == NULL; |
| objfile = objfile->next) |
| { |
| if (objf == NULL || objf == objfile) |
| { |
| /* Do two passes: the first over the ordinary hash table, |
| and the second over the demangled hash table. */ |
| int pass; |
| |
| for (pass = 1; pass <= 2 && found_symbol == NULL; pass++) |
| { |
| /* Select hash list according to pass. */ |
| if (pass == 1) |
| msymbol = objfile->msymbol_hash[hash]; |
| else |
| msymbol = objfile->msymbol_demangled_hash[dem_hash]; |
| |
| while (msymbol != NULL && found_symbol == NULL) |
| { |
| if (SYMBOL_MATCHES_NAME (msymbol, name)) |
| { |
| switch (MSYMBOL_TYPE (msymbol)) |
| { |
| case mst_file_text: |
| case mst_file_data: |
| case mst_file_bss: |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| if (sfile == NULL || STREQ (msymbol->filename, sfile)) |
| found_file_symbol = msymbol; |
| #else |
| /* We have neither the ability nor the need to |
| deal with the SFILE parameter. If we find |
| more than one symbol, just return the latest |
| one (the user can't expect useful behavior in |
| that case). */ |
| found_file_symbol = msymbol; |
| #endif |
| break; |
| |
| case mst_solib_trampoline: |
| |
| /* If a trampoline symbol is found, we prefer to |
| keep looking for the *real* symbol. If the |
| actual symbol is not found, then we'll use the |
| trampoline entry. */ |
| if (trampoline_symbol == NULL) |
| trampoline_symbol = msymbol; |
| break; |
| |
| case mst_unknown: |
| default: |
| found_symbol = msymbol; |
| break; |
| } |
| } |
| |
| /* Find the next symbol on the hash chain. */ |
| if (pass == 1) |
| msymbol = msymbol->hash_next; |
| else |
| msymbol = msymbol->demangled_hash_next; |
| } |
| } |
| } |
| } |
| /* External symbols are best. */ |
| if (found_symbol) |
| return found_symbol; |
| |
| /* File-local symbols are next best. */ |
| if (found_file_symbol) |
| return found_file_symbol; |
| |
| /* Symbols for shared library trampolines are next best. */ |
| if (trampoline_symbol) |
| return trampoline_symbol; |
| |
| return NULL; |
| } |
| |
| /* Look through all the current minimal symbol tables and find the |
| first minimal symbol that matches NAME and of text type. |
| If OBJF is non-NULL, limit |
| the search to that objfile. If SFILE is non-NULL, limit the search |
| to that source file. Returns a pointer to the minimal symbol that |
| matches, or NULL if no match is found. |
| */ |
| |
| struct minimal_symbol * |
| lookup_minimal_symbol_text (register const char *name, const char *sfile, |
| struct objfile *objf) |
| { |
| struct objfile *objfile; |
| struct minimal_symbol *msymbol; |
| struct minimal_symbol *found_symbol = NULL; |
| struct minimal_symbol *found_file_symbol = NULL; |
| |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| if (sfile != NULL) |
| { |
| char *p = strrchr (sfile, '/'); |
| if (p != NULL) |
| sfile = p + 1; |
| } |
| #endif |
| |
| for (objfile = object_files; |
| objfile != NULL && found_symbol == NULL; |
| objfile = objfile->next) |
| { |
| if (objf == NULL || objf == objfile) |
| { |
| for (msymbol = objfile->msymbols; |
| msymbol != NULL && SYMBOL_NAME (msymbol) != NULL && |
| found_symbol == NULL; |
| msymbol++) |
| { |
| if (SYMBOL_MATCHES_NAME (msymbol, name) && |
| (MSYMBOL_TYPE (msymbol) == mst_text || |
| MSYMBOL_TYPE (msymbol) == mst_file_text)) |
| { |
| switch (MSYMBOL_TYPE (msymbol)) |
| { |
| case mst_file_text: |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| if (sfile == NULL || STREQ (msymbol->filename, sfile)) |
| found_file_symbol = msymbol; |
| #else |
| /* We have neither the ability nor the need to |
| deal with the SFILE parameter. If we find |
| more than one symbol, just return the latest |
| one (the user can't expect useful behavior in |
| that case). */ |
| found_file_symbol = msymbol; |
| #endif |
| break; |
| default: |
| found_symbol = msymbol; |
| break; |
| } |
| } |
| } |
| } |
| } |
| /* External symbols are best. */ |
| if (found_symbol) |
| return found_symbol; |
| |
| /* File-local symbols are next best. */ |
| if (found_file_symbol) |
| return found_file_symbol; |
| |
| return NULL; |
| } |
| |
| /* Look through all the current minimal symbol tables and find the |
| first minimal symbol that matches NAME and of solib trampoline type. |
| If OBJF is non-NULL, limit |
| the search to that objfile. If SFILE is non-NULL, limit the search |
| to that source file. Returns a pointer to the minimal symbol that |
| matches, or NULL if no match is found. |
| */ |
| |
| struct minimal_symbol * |
| lookup_minimal_symbol_solib_trampoline (register const char *name, |
| const char *sfile, struct objfile *objf) |
| { |
| struct objfile *objfile; |
| struct minimal_symbol *msymbol; |
| struct minimal_symbol *found_symbol = NULL; |
| |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| if (sfile != NULL) |
| { |
| char *p = strrchr (sfile, '/'); |
| if (p != NULL) |
| sfile = p + 1; |
| } |
| #endif |
| |
| for (objfile = object_files; |
| objfile != NULL && found_symbol == NULL; |
| objfile = objfile->next) |
| { |
| if (objf == NULL || objf == objfile) |
| { |
| for (msymbol = objfile->msymbols; |
| msymbol != NULL && SYMBOL_NAME (msymbol) != NULL && |
| found_symbol == NULL; |
| msymbol++) |
| { |
| if (SYMBOL_MATCHES_NAME (msymbol, name) && |
| MSYMBOL_TYPE (msymbol) == mst_solib_trampoline) |
| return msymbol; |
| } |
| } |
| } |
| |
| return NULL; |
| } |
| |
| |
| /* Search through the minimal symbol table for each objfile and find |
| the symbol whose address is the largest address that is still less |
| than or equal to PC, and matches SECTION (if non-null). Returns a |
| pointer to the minimal symbol if such a symbol is found, or NULL if |
| PC is not in a suitable range. Note that we need to look through |
| ALL the minimal symbol tables before deciding on the symbol that |
| comes closest to the specified PC. This is because objfiles can |
| overlap, for example objfile A has .text at 0x100 and .data at |
| 0x40000 and objfile B has .text at 0x234 and .data at 0x40048. */ |
| |
| struct minimal_symbol * |
| lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, asection *section) |
| { |
| int lo; |
| int hi; |
| int new; |
| struct objfile *objfile; |
| struct minimal_symbol *msymbol; |
| struct minimal_symbol *best_symbol = NULL; |
| |
| /* pc has to be in a known section. This ensures that anything beyond |
| the end of the last segment doesn't appear to be part of the last |
| function in the last segment. */ |
| if (find_pc_section (pc) == NULL) |
| return NULL; |
| |
| for (objfile = object_files; |
| objfile != NULL; |
| objfile = objfile->next) |
| { |
| /* If this objfile has a minimal symbol table, go search it using |
| a binary search. Note that a minimal symbol table always consists |
| of at least two symbols, a "real" symbol and the terminating |
| "null symbol". If there are no real symbols, then there is no |
| minimal symbol table at all. */ |
| |
| if ((msymbol = objfile->msymbols) != NULL) |
| { |
| lo = 0; |
| hi = objfile->minimal_symbol_count - 1; |
| |
| /* This code assumes that the minimal symbols are sorted by |
| ascending address values. If the pc value is greater than or |
| equal to the first symbol's address, then some symbol in this |
| minimal symbol table is a suitable candidate for being the |
| "best" symbol. This includes the last real symbol, for cases |
| where the pc value is larger than any address in this vector. |
| |
| By iterating until the address associated with the current |
| hi index (the endpoint of the test interval) is less than |
| or equal to the desired pc value, we accomplish two things: |
| (1) the case where the pc value is larger than any minimal |
| symbol address is trivially solved, (2) the address associated |
| 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)); |
| } |
| |
| #ifdef SOFUN_ADDRESS_MAYBE_MISSING |
| CORE_ADDR |
| find_stab_function_addr (char *namestring, char *filename, |
| struct objfile *objfile) |
| { |
| struct minimal_symbol *msym; |
| char *p; |
| int n; |
| |
| p = strchr (namestring, ':'); |
| if (p == NULL) |
| p = namestring; |
| n = p - namestring; |
| p = alloca (n + 2); |
| strncpy (p, namestring, n); |
| p[n] = 0; |
| |
| msym = lookup_minimal_symbol (p, filename, objfile); |
| if (msym == NULL) |
| { |
| /* Sun Fortran appends an underscore to the minimal symbol name, |
| try again with an appended underscore if the minimal symbol |
| was not found. */ |
| p[n] = '_'; |
| p[n + 1] = 0; |
| msym = lookup_minimal_symbol (p, filename, objfile); |
| } |
| |
| if (msym == NULL && filename != NULL) |
| { |
| /* Try again without the filename. */ |
| p[n] = 0; |
| msym = lookup_minimal_symbol (p, 0, objfile); |
| } |
| if (msym == NULL && filename != NULL) |
| { |
| /* And try again for Sun Fortran, but without the filename. */ |
| p[n] = '_'; |
| p[n + 1] = 0; |
| msym = lookup_minimal_symbol (p, 0, objfile); |
| } |
| |
| return msym == NULL ? 0 : SYMBOL_VALUE_ADDRESS (msym); |
| } |
| #endif /* SOFUN_ADDRESS_MAYBE_MISSING */ |
| |
| |
| /* 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) |
| { |
| register struct msym_bunch *new; |
| register 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_NAME (msymbol) = obsavestring ((char *) name, strlen (name), |
| &objfile->symbol_obstack); |
| SYMBOL_INIT_LANGUAGE_SPECIFIC (msymbol, language_unknown); |
| 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 PTR fn1p, const PTR fn2p) |
| { |
| register const struct minimal_symbol *fn1; |
| register 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_NAME (fn1); |
| char *name2 = SYMBOL_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) |
| { |
| register 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_NAME (copyfrom), SYMBOL_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) |
| { |
| register int bindex; |
| register int mcount; |
| register struct msym_bunch *bunch; |
| register struct minimal_symbol *msymbols; |
| int alloc_count; |
| register 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]; |
| SYMBOL_LANGUAGE (&msymbols[mcount]) = language_auto; |
| if (SYMBOL_NAME (&msymbols[mcount])[0] == leading_char) |
| { |
| SYMBOL_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_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; |
| |
| /* Now walk through all the minimal symbols, selecting the newly added |
| ones and attempting to cache their C++ demangled names. */ |
| |
| for (; mcount-- > 0; msymbols++) |
| SYMBOL_INIT_DEMANGLED_NAME (msymbols, &objfile->symbol_obstack); |
| |
| /* 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_NAME (msymbol), SYMBOL_NAME (tsymbol))) |
| return SYMBOL_VALUE_ADDRESS (msymbol); |
| } |
| } |
| return 0; |
| } |