| /* GDB routines for manipulating the minimal symbol tables. |
| Copyright (C) 1992-2021 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 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| |
| /* 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 "symtab.h" |
| #include "bfd.h" |
| #include "filenames.h" |
| #include "symfile.h" |
| #include "objfiles.h" |
| #include "demangle.h" |
| #include "value.h" |
| #include "cp-abi.h" |
| #include "target.h" |
| #include "cp-support.h" |
| #include "language.h" |
| #include "cli/cli-utils.h" |
| #include "gdbsupport/symbol.h" |
| #include <algorithm> |
| #include "safe-ctype.h" |
| #include "gdbsupport/parallel-for.h" |
| #include "inferior.h" |
| |
| #if CXX_STD_THREAD |
| #include <mutex> |
| #endif |
| |
| /* Return true if MINSYM is a cold clone symbol. |
| Recognize f.i. these symbols (mangled/demangled): |
| - _ZL3foov.cold |
| foo() [clone .cold] |
| - _ZL9do_rpo_vnP8functionP8edge_defP11bitmap_headbb.cold.138 |
| do_rpo_vn(function*, edge_def*, bitmap_head*, bool, bool) \ |
| [clone .cold.138]. */ |
| |
| static bool |
| msymbol_is_cold_clone (minimal_symbol *minsym) |
| { |
| const char *name = minsym->natural_name (); |
| size_t name_len = strlen (name); |
| if (name_len < 1) |
| return false; |
| |
| const char *last = &name[name_len - 1]; |
| if (*last != ']') |
| return false; |
| |
| const char *suffix = " [clone .cold"; |
| size_t suffix_len = strlen (suffix); |
| const char *found = strstr (name, suffix); |
| if (found == nullptr) |
| return false; |
| |
| const char *start = &found[suffix_len]; |
| if (*start == ']') |
| return true; |
| |
| if (*start != '.') |
| return false; |
| |
| const char *p; |
| for (p = start + 1; p <= last; ++p) |
| { |
| if (*p >= '0' && *p <= '9') |
| continue; |
| break; |
| } |
| |
| if (p == last) |
| return true; |
| |
| return false; |
| } |
| |
| /* See minsyms.h. */ |
| |
| bool |
| msymbol_is_function (struct objfile *objfile, minimal_symbol *minsym, |
| CORE_ADDR *func_address_p) |
| { |
| CORE_ADDR msym_addr = MSYMBOL_VALUE_ADDRESS (objfile, minsym); |
| |
| switch (minsym->type) |
| { |
| case mst_slot_got_plt: |
| case mst_data: |
| case mst_bss: |
| case mst_abs: |
| case mst_file_data: |
| case mst_file_bss: |
| case mst_data_gnu_ifunc: |
| { |
| struct gdbarch *gdbarch = objfile->arch (); |
| CORE_ADDR pc = gdbarch_convert_from_func_ptr_addr |
| (gdbarch, msym_addr, current_inferior ()->top_target ()); |
| if (pc != msym_addr) |
| { |
| if (func_address_p != NULL) |
| *func_address_p = pc; |
| return true; |
| } |
| return false; |
| } |
| case mst_file_text: |
| /* Ignore function symbol that is not a function entry. */ |
| if (msymbol_is_cold_clone (minsym)) |
| return false; |
| /* fallthru */ |
| default: |
| if (func_address_p != NULL) |
| *func_address_p = msym_addr; |
| return true; |
| } |
| } |
| |
| /* Accumulate the minimal symbols for each objfile in bunches of BUNCH_SIZE. |
| At the end, copy them all into one newly allocated array. */ |
| |
| #define BUNCH_SIZE 127 |
| |
| struct msym_bunch |
| { |
| struct msym_bunch *next; |
| struct minimal_symbol contents[BUNCH_SIZE]; |
| }; |
| |
| /* See minsyms.h. */ |
| |
| unsigned int |
| msymbol_hash_iw (const char *string) |
| { |
| unsigned int hash = 0; |
| |
| while (*string && *string != '(') |
| { |
| string = skip_spaces (string); |
| if (*string && *string != '(') |
| { |
| hash = SYMBOL_HASH_NEXT (hash, *string); |
| ++string; |
| } |
| } |
| return hash; |
| } |
| |
| /* See minsyms.h. */ |
| |
| unsigned int |
| msymbol_hash (const char *string) |
| { |
| unsigned int hash = 0; |
| |
| for (; *string; ++string) |
| hash = SYMBOL_HASH_NEXT (hash, *string); |
| return hash; |
| } |
| |
| /* Add the minimal symbol SYM to an objfile's minsym hash table, TABLE. */ |
| static void |
| add_minsym_to_hash_table (struct minimal_symbol *sym, |
| struct minimal_symbol **table, |
| unsigned int hash_value) |
| { |
| if (sym->hash_next == NULL) |
| { |
| unsigned int hash = hash_value % MINIMAL_SYMBOL_HASH_SIZE; |
| |
| 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 objfile *objfile, |
| unsigned int hash_value) |
| { |
| if (sym->demangled_hash_next == NULL) |
| { |
| objfile->per_bfd->demangled_hash_languages.set (sym->language ()); |
| |
| struct minimal_symbol **table |
| = objfile->per_bfd->msymbol_demangled_hash; |
| unsigned int hash_index = hash_value % MINIMAL_SYMBOL_HASH_SIZE; |
| sym->demangled_hash_next = table[hash_index]; |
| table[hash_index] = sym; |
| } |
| } |
| |
| /* Worker object for lookup_minimal_symbol. Stores temporary results |
| while walking the symbol tables. */ |
| |
| struct found_minimal_symbols |
| { |
| /* External symbols are best. */ |
| bound_minimal_symbol external_symbol {}; |
| |
| /* File-local symbols are next best. */ |
| bound_minimal_symbol file_symbol {}; |
| |
| /* Symbols for shared library trampolines are next best. */ |
| bound_minimal_symbol trampoline_symbol {}; |
| |
| /* Called when a symbol name matches. Check if the minsym is a |
| better type than what we had already found, and record it in one |
| of the members fields if so. Returns true if we collected the |
| real symbol, in which case we can stop searching. */ |
| bool maybe_collect (const char *sfile, objfile *objf, |
| minimal_symbol *msymbol); |
| }; |
| |
| /* See declaration above. */ |
| |
| bool |
| found_minimal_symbols::maybe_collect (const char *sfile, |
| struct objfile *objfile, |
| minimal_symbol *msymbol) |
| { |
| switch (MSYMBOL_TYPE (msymbol)) |
| { |
| case mst_file_text: |
| case mst_file_data: |
| case mst_file_bss: |
| if (sfile == NULL |
| || filename_cmp (msymbol->filename, sfile) == 0) |
| { |
| file_symbol.minsym = msymbol; |
| file_symbol.objfile = objfile; |
| } |
| 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.minsym == NULL) |
| { |
| trampoline_symbol.minsym = msymbol; |
| trampoline_symbol.objfile = objfile; |
| } |
| break; |
| |
| case mst_unknown: |
| default: |
| external_symbol.minsym = msymbol; |
| external_symbol.objfile = objfile; |
| /* We have the real symbol. No use looking further. */ |
| return true; |
| } |
| |
| /* Keep looking. */ |
| return false; |
| } |
| |
| /* Walk the mangled name hash table, and pass each symbol whose name |
| matches LOOKUP_NAME according to NAMECMP to FOUND. */ |
| |
| static void |
| lookup_minimal_symbol_mangled (const char *lookup_name, |
| const char *sfile, |
| struct objfile *objfile, |
| struct minimal_symbol **table, |
| unsigned int hash, |
| int (*namecmp) (const char *, const char *), |
| found_minimal_symbols &found) |
| { |
| for (minimal_symbol *msymbol = table[hash]; |
| msymbol != NULL; |
| msymbol = msymbol->hash_next) |
| { |
| const char *symbol_name = msymbol->linkage_name (); |
| |
| if (namecmp (symbol_name, lookup_name) == 0 |
| && found.maybe_collect (sfile, objfile, msymbol)) |
| return; |
| } |
| } |
| |
| /* Walk the demangled name hash table, and pass each symbol whose name |
| matches LOOKUP_NAME according to MATCHER to FOUND. */ |
| |
| static void |
| lookup_minimal_symbol_demangled (const lookup_name_info &lookup_name, |
| const char *sfile, |
| struct objfile *objfile, |
| struct minimal_symbol **table, |
| unsigned int hash, |
| symbol_name_matcher_ftype *matcher, |
| found_minimal_symbols &found) |
| { |
| for (minimal_symbol *msymbol = table[hash]; |
| msymbol != NULL; |
| msymbol = msymbol->demangled_hash_next) |
| { |
| const char *symbol_name = msymbol->search_name (); |
| |
| if (matcher (symbol_name, lookup_name, NULL) |
| && found.maybe_collect (sfile, objfile, msymbol)) |
| return; |
| } |
| } |
| |
| /* 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, the only file-scope |
| symbols considered will be from that source file (global symbols are |
| still preferred). 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). |
| |
| It's also possible to have minimal symbols with different mangled |
| names, but identical demangled names. For example, the GNU C++ v3 |
| ABI requires the generation of two (or perhaps three) copies of |
| constructor functions --- "in-charge", "not-in-charge", and |
| "allocate" copies; destructors may be duplicated as well. |
| Obviously, there must be distinct mangled names for each of these, |
| but the demangled names are all the same: S::S or S::~S. */ |
| |
| struct bound_minimal_symbol |
| lookup_minimal_symbol (const char *name, const char *sfile, |
| struct objfile *objf) |
| { |
| found_minimal_symbols found; |
| |
| unsigned int mangled_hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
| |
| auto *mangled_cmp |
| = (case_sensitivity == case_sensitive_on |
| ? strcmp |
| : strcasecmp); |
| |
| if (sfile != NULL) |
| sfile = lbasename (sfile); |
| |
| lookup_name_info lookup_name (name, symbol_name_match_type::FULL); |
| |
| for (objfile *objfile : current_program_space->objfiles ()) |
| { |
| if (found.external_symbol.minsym != NULL) |
| break; |
| |
| if (objf == NULL || objf == objfile |
| || objf == objfile->separate_debug_objfile_backlink) |
| { |
| if (symbol_lookup_debug) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "lookup_minimal_symbol (%s, %s, %s)\n", |
| name, sfile != NULL ? sfile : "NULL", |
| objfile_debug_name (objfile)); |
| } |
| |
| /* Do two passes: the first over the ordinary hash table, |
| and the second over the demangled hash table. */ |
| lookup_minimal_symbol_mangled (name, sfile, objfile, |
| objfile->per_bfd->msymbol_hash, |
| mangled_hash, mangled_cmp, found); |
| |
| /* If not found, try the demangled hash table. */ |
| if (found.external_symbol.minsym == NULL) |
| { |
| /* Once for each language in the demangled hash names |
| table (usually just zero or one languages). */ |
| for (unsigned iter = 0; iter < nr_languages; ++iter) |
| { |
| if (!objfile->per_bfd->demangled_hash_languages.test (iter)) |
| continue; |
| enum language lang = (enum language) iter; |
| |
| unsigned int hash |
| = (lookup_name.search_name_hash (lang) |
| % MINIMAL_SYMBOL_HASH_SIZE); |
| |
| symbol_name_matcher_ftype *match |
| = language_def (lang)->get_symbol_name_matcher |
| (lookup_name); |
| struct minimal_symbol **msymbol_demangled_hash |
| = objfile->per_bfd->msymbol_demangled_hash; |
| |
| lookup_minimal_symbol_demangled (lookup_name, sfile, objfile, |
| msymbol_demangled_hash, |
| hash, match, found); |
| |
| if (found.external_symbol.minsym != NULL) |
| break; |
| } |
| } |
| } |
| } |
| |
| /* External symbols are best. */ |
| if (found.external_symbol.minsym != NULL) |
| { |
| if (symbol_lookup_debug) |
| { |
| minimal_symbol *minsym = found.external_symbol.minsym; |
| |
| fprintf_unfiltered (gdb_stdlog, |
| "lookup_minimal_symbol (...) = %s (external)\n", |
| host_address_to_string (minsym)); |
| } |
| return found.external_symbol; |
| } |
| |
| /* File-local symbols are next best. */ |
| if (found.file_symbol.minsym != NULL) |
| { |
| if (symbol_lookup_debug) |
| { |
| minimal_symbol *minsym = found.file_symbol.minsym; |
| |
| fprintf_unfiltered (gdb_stdlog, |
| "lookup_minimal_symbol (...) = %s (file-local)\n", |
| host_address_to_string (minsym)); |
| } |
| return found.file_symbol; |
| } |
| |
| /* Symbols for shared library trampolines are next best. */ |
| if (found.trampoline_symbol.minsym != NULL) |
| { |
| if (symbol_lookup_debug) |
| { |
| minimal_symbol *minsym = found.trampoline_symbol.minsym; |
| |
| fprintf_unfiltered (gdb_stdlog, |
| "lookup_minimal_symbol (...) = %s (trampoline)\n", |
| host_address_to_string (minsym)); |
| } |
| |
| return found.trampoline_symbol; |
| } |
| |
| /* Not found. */ |
| if (symbol_lookup_debug) |
| fprintf_unfiltered (gdb_stdlog, "lookup_minimal_symbol (...) = NULL\n"); |
| return {}; |
| } |
| |
| /* See minsyms.h. */ |
| |
| struct bound_minimal_symbol |
| lookup_bound_minimal_symbol (const char *name) |
| { |
| return lookup_minimal_symbol (name, NULL, NULL); |
| } |
| |
| /* See gdbsupport/symbol.h. */ |
| |
| int |
| find_minimal_symbol_address (const char *name, CORE_ADDR *addr, |
| struct objfile *objfile) |
| { |
| struct bound_minimal_symbol sym |
| = lookup_minimal_symbol (name, NULL, objfile); |
| |
| if (sym.minsym != NULL) |
| *addr = BMSYMBOL_VALUE_ADDRESS (sym); |
| |
| return sym.minsym == NULL; |
| } |
| |
| /* Get the lookup name form best suitable for linkage name |
| matching. */ |
| |
| static const char * |
| linkage_name_str (const lookup_name_info &lookup_name) |
| { |
| /* Unlike most languages (including C++), Ada uses the |
| encoded/linkage name as the search name recorded in symbols. So |
| if debugging in Ada mode, prefer the Ada-encoded name. This also |
| makes Ada's verbatim match syntax ("<...>") work, because |
| "lookup_name.name()" includes the "<>"s, while |
| "lookup_name.ada().lookup_name()" is the encoded name with "<>"s |
| stripped. */ |
| if (current_language->la_language == language_ada) |
| return lookup_name.ada ().lookup_name ().c_str (); |
| |
| return lookup_name.c_str (); |
| } |
| |
| /* See minsyms.h. */ |
| |
| void |
| iterate_over_minimal_symbols |
| (struct objfile *objf, const lookup_name_info &lookup_name, |
| gdb::function_view<bool (struct minimal_symbol *)> callback) |
| { |
| /* The first pass is over the ordinary hash table. */ |
| { |
| const char *name = linkage_name_str (lookup_name); |
| unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
| auto *mangled_cmp |
| = (case_sensitivity == case_sensitive_on |
| ? strcmp |
| : strcasecmp); |
| |
| for (minimal_symbol *iter = objf->per_bfd->msymbol_hash[hash]; |
| iter != NULL; |
| iter = iter->hash_next) |
| { |
| if (mangled_cmp (iter->linkage_name (), name) == 0) |
| if (callback (iter)) |
| return; |
| } |
| } |
| |
| /* The second pass is over the demangled table. Once for each |
| language in the demangled hash names table (usually just zero or |
| one). */ |
| for (unsigned liter = 0; liter < nr_languages; ++liter) |
| { |
| if (!objf->per_bfd->demangled_hash_languages.test (liter)) |
| continue; |
| |
| enum language lang = (enum language) liter; |
| const language_defn *lang_def = language_def (lang); |
| symbol_name_matcher_ftype *name_match |
| = lang_def->get_symbol_name_matcher (lookup_name); |
| |
| unsigned int hash |
| = lookup_name.search_name_hash (lang) % MINIMAL_SYMBOL_HASH_SIZE; |
| for (minimal_symbol *iter = objf->per_bfd->msymbol_demangled_hash[hash]; |
| iter != NULL; |
| iter = iter->demangled_hash_next) |
| if (name_match (iter->search_name (), lookup_name, NULL)) |
| if (callback (iter)) |
| return; |
| } |
| } |
| |
| /* See minsyms.h. */ |
| |
| bound_minimal_symbol |
| lookup_minimal_symbol_linkage (const char *name, struct objfile *objf) |
| { |
| unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
| |
| for (objfile *objfile : objf->separate_debug_objfiles ()) |
| { |
| for (minimal_symbol *msymbol = objfile->per_bfd->msymbol_hash[hash]; |
| msymbol != NULL; |
| msymbol = msymbol->hash_next) |
| { |
| if (strcmp (msymbol->linkage_name (), name) == 0 |
| && (MSYMBOL_TYPE (msymbol) == mst_data |
| || MSYMBOL_TYPE (msymbol) == mst_bss)) |
| return {msymbol, objfile}; |
| } |
| } |
| |
| return {}; |
| } |
| |
| /* See minsyms.h. */ |
| |
| struct bound_minimal_symbol |
| lookup_minimal_symbol_text (const char *name, struct objfile *objf) |
| { |
| struct minimal_symbol *msymbol; |
| struct bound_minimal_symbol found_symbol = { NULL, NULL }; |
| struct bound_minimal_symbol found_file_symbol = { NULL, NULL }; |
| |
| unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
| |
| for (objfile *objfile : current_program_space->objfiles ()) |
| { |
| if (found_symbol.minsym != NULL) |
| break; |
| |
| if (objf == NULL || objf == objfile |
| || objf == objfile->separate_debug_objfile_backlink) |
| { |
| for (msymbol = objfile->per_bfd->msymbol_hash[hash]; |
| msymbol != NULL && found_symbol.minsym == NULL; |
| msymbol = msymbol->hash_next) |
| { |
| if (strcmp (msymbol->linkage_name (), name) == 0 && |
| (MSYMBOL_TYPE (msymbol) == mst_text |
| || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc |
| || MSYMBOL_TYPE (msymbol) == mst_file_text)) |
| { |
| switch (MSYMBOL_TYPE (msymbol)) |
| { |
| case mst_file_text: |
| found_file_symbol.minsym = msymbol; |
| found_file_symbol.objfile = objfile; |
| break; |
| default: |
| found_symbol.minsym = msymbol; |
| found_symbol.objfile = objfile; |
| break; |
| } |
| } |
| } |
| } |
| } |
| /* External symbols are best. */ |
| if (found_symbol.minsym) |
| return found_symbol; |
| |
| /* File-local symbols are next best. */ |
| return found_file_symbol; |
| } |
| |
| /* See minsyms.h. */ |
| |
| struct minimal_symbol * |
| lookup_minimal_symbol_by_pc_name (CORE_ADDR pc, const char *name, |
| struct objfile *objf) |
| { |
| struct minimal_symbol *msymbol; |
| |
| unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE; |
| |
| for (objfile *objfile : current_program_space->objfiles ()) |
| { |
| if (objf == NULL || objf == objfile |
| || objf == objfile->separate_debug_objfile_backlink) |
| { |
| for (msymbol = objfile->per_bfd->msymbol_hash[hash]; |
| msymbol != NULL; |
| msymbol = msymbol->hash_next) |
| { |
| if (MSYMBOL_VALUE_ADDRESS (objfile, msymbol) == pc |
| && strcmp (msymbol->linkage_name (), name) == 0) |
| return msymbol; |
| } |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* A helper function that makes *PC section-relative. This searches |
| the sections of OBJFILE and if *PC is in a section, it subtracts |
| the section offset and returns true. Otherwise it returns |
| false. */ |
| |
| static int |
| frob_address (struct objfile *objfile, CORE_ADDR *pc) |
| { |
| struct obj_section *iter; |
| |
| ALL_OBJFILE_OSECTIONS (objfile, iter) |
| { |
| if (*pc >= iter->addr () && *pc < iter->endaddr ()) |
| { |
| *pc -= iter->offset (); |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Helper for lookup_minimal_symbol_by_pc_section. Convert a |
| lookup_msym_prefer to a minimal_symbol_type. */ |
| |
| static minimal_symbol_type |
| msym_prefer_to_msym_type (lookup_msym_prefer prefer) |
| { |
| switch (prefer) |
| { |
| case lookup_msym_prefer::TEXT: |
| return mst_text; |
| case lookup_msym_prefer::TRAMPOLINE: |
| return mst_solib_trampoline; |
| case lookup_msym_prefer::GNU_IFUNC: |
| return mst_text_gnu_ifunc; |
| } |
| |
| /* Assert here instead of in a default switch case above so that |
| -Wswitch warns if a new enumerator is added. */ |
| gdb_assert_not_reached ("unhandled lookup_msym_prefer"); |
| } |
| |
| /* See minsyms.h. |
| |
| 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. */ |
| |
| bound_minimal_symbol |
| lookup_minimal_symbol_by_pc_section (CORE_ADDR pc_in, struct obj_section *section, |
| lookup_msym_prefer prefer, |
| bound_minimal_symbol *previous) |
| { |
| int lo; |
| int hi; |
| int newobj; |
| struct minimal_symbol *msymbol; |
| struct minimal_symbol *best_symbol = NULL; |
| struct objfile *best_objfile = NULL; |
| struct bound_minimal_symbol result; |
| |
| if (previous != nullptr) |
| { |
| previous->minsym = nullptr; |
| previous->objfile = nullptr; |
| } |
| |
| if (section == NULL) |
| { |
| section = find_pc_section (pc_in); |
| if (section == NULL) |
| return {}; |
| } |
| |
| minimal_symbol_type want_type = msym_prefer_to_msym_type (prefer); |
| |
| /* We can not require the symbol found to be in section, because |
| e.g. IRIX 6.5 mdebug relies on this code returning an absolute |
| symbol - but find_pc_section won't return an absolute section and |
| hence the code below would skip over absolute symbols. We can |
| still take advantage of the call to find_pc_section, though - the |
| object file still must match. In case we have separate debug |
| files, search both the file and its separate debug file. There's |
| no telling which one will have the minimal symbols. */ |
| |
| gdb_assert (section != NULL); |
| |
| for (objfile *objfile : section->objfile->separate_debug_objfiles ()) |
| { |
| CORE_ADDR pc = pc_in; |
| |
| /* If this objfile has a minimal symbol table, go search it |
| using a binary search. */ |
| |
| if (objfile->per_bfd->minimal_symbol_count > 0) |
| { |
| int best_zero_sized = -1; |
| |
| msymbol = objfile->per_bfd->msymbols.get (); |
| lo = 0; |
| hi = objfile->per_bfd->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 iteration |
| 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. */ |
| |
| if (frob_address (objfile, &pc) |
| && pc >= MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[lo])) |
| { |
| while (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) > pc) |
| { |
| /* pc is still strictly less than highest address. */ |
| /* Note "new" will always be >= lo. */ |
| newobj = (lo + hi) / 2; |
| if ((MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[newobj]) >= pc) |
| || (lo == newobj)) |
| { |
| hi = newobj; |
| } |
| else |
| { |
| lo = newobj; |
| } |
| } |
| |
| /* 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->per_bfd->minimal_symbol_count - 1 |
| && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) |
| == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi + 1]))) |
| hi++; |
| |
| /* Skip various undesirable symbols. */ |
| while (hi >= 0) |
| { |
| /* 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. */ |
| |
| if (MSYMBOL_TYPE (&msymbol[hi]) == mst_abs) |
| { |
| hi--; |
| continue; |
| } |
| |
| /* If SECTION was specified, skip any symbol from |
| wrong section. */ |
| if (section |
| /* Some types of debug info, such as COFF, |
| don't fill the bfd_section member, so don't |
| throw away symbols on those platforms. */ |
| && msymbol[hi].obj_section (objfile) != nullptr |
| && (!matching_obj_sections |
| (msymbol[hi].obj_section (objfile), |
| section))) |
| { |
| hi--; |
| continue; |
| } |
| |
| /* If we are looking for a trampoline and this is a |
| text symbol, or the other way around, check the |
| preceding symbol too. If they are otherwise |
| identical prefer that one. */ |
| if (hi > 0 |
| && MSYMBOL_TYPE (&msymbol[hi]) != want_type |
| && MSYMBOL_TYPE (&msymbol[hi - 1]) == want_type |
| && (MSYMBOL_SIZE (&msymbol[hi]) |
| == MSYMBOL_SIZE (&msymbol[hi - 1])) |
| && (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) |
| == MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1])) |
| && (msymbol[hi].obj_section (objfile) |
| == msymbol[hi - 1].obj_section (objfile))) |
| { |
| hi--; |
| continue; |
| } |
| |
| /* If the minimal symbol has a zero size, save it |
| but keep scanning backwards looking for one with |
| a non-zero size. A zero size may mean that the |
| symbol isn't an object or function (e.g. a |
| label), or it may just mean that the size was not |
| specified. */ |
| if (MSYMBOL_SIZE (&msymbol[hi]) == 0) |
| { |
| if (best_zero_sized == -1) |
| best_zero_sized = hi; |
| hi--; |
| continue; |
| } |
| |
| /* If we are past the end of the current symbol, try |
| the previous symbol if it has a larger overlapping |
| size. This happens on i686-pc-linux-gnu with glibc; |
| the nocancel variants of system calls are inside |
| the cancellable variants, but both have sizes. */ |
| if (hi > 0 |
| && MSYMBOL_SIZE (&msymbol[hi]) != 0 |
| && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) |
| + MSYMBOL_SIZE (&msymbol[hi])) |
| && pc < (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi - 1]) |
| + MSYMBOL_SIZE (&msymbol[hi - 1]))) |
| { |
| hi--; |
| continue; |
| } |
| |
| /* Otherwise, this symbol must be as good as we're going |
| to get. */ |
| break; |
| } |
| |
| /* If HI has a zero size, and best_zero_sized is set, |
| then we had two or more zero-sized symbols; prefer |
| the first one we found (which may have a higher |
| address). Also, if we ran off the end, be sure |
| to back up. */ |
| if (best_zero_sized != -1 |
| && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0)) |
| hi = best_zero_sized; |
| |
| /* If the minimal symbol has a non-zero size, and this |
| PC appears to be outside the symbol's contents, then |
| refuse to use this symbol. If we found a zero-sized |
| symbol with an address greater than this symbol's, |
| use that instead. We assume that if symbols have |
| specified sizes, they do not overlap. */ |
| |
| if (hi >= 0 |
| && MSYMBOL_SIZE (&msymbol[hi]) != 0 |
| && pc >= (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) |
| + MSYMBOL_SIZE (&msymbol[hi]))) |
| { |
| if (best_zero_sized != -1) |
| hi = best_zero_sized; |
| else |
| { |
| /* If needed record this symbol as the closest |
| previous symbol. */ |
| if (previous != nullptr) |
| { |
| if (previous->minsym == nullptr |
| || (MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi]) |
| > MSYMBOL_VALUE_RAW_ADDRESS |
| (previous->minsym))) |
| { |
| previous->minsym = &msymbol[hi]; |
| previous->objfile = objfile; |
| } |
| } |
| /* Go on to the next object file. */ |
| continue; |
| } |
| } |
| |
| /* 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. */ |
| |
| if (hi >= 0 |
| && ((best_symbol == NULL) || |
| (MSYMBOL_VALUE_RAW_ADDRESS (best_symbol) < |
| MSYMBOL_VALUE_RAW_ADDRESS (&msymbol[hi])))) |
| { |
| best_symbol = &msymbol[hi]; |
| best_objfile = objfile; |
| } |
| } |
| } |
| } |
| |
| result.minsym = best_symbol; |
| result.objfile = best_objfile; |
| return result; |
| } |
| |
| /* See minsyms.h. */ |
| |
| struct bound_minimal_symbol |
| lookup_minimal_symbol_by_pc (CORE_ADDR pc) |
| { |
| return lookup_minimal_symbol_by_pc_section (pc, NULL); |
| } |
| |
| /* Return non-zero iff PC is in an STT_GNU_IFUNC function resolver. */ |
| |
| bool |
| in_gnu_ifunc_stub (CORE_ADDR pc) |
| { |
| bound_minimal_symbol msymbol |
| = lookup_minimal_symbol_by_pc_section (pc, NULL, |
| lookup_msym_prefer::GNU_IFUNC); |
| return msymbol.minsym && MSYMBOL_TYPE (msymbol.minsym) == mst_text_gnu_ifunc; |
| } |
| |
| /* See elf_gnu_ifunc_resolve_addr for its real implementation. */ |
| |
| static CORE_ADDR |
| stub_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc) |
| { |
| error (_("GDB cannot resolve STT_GNU_IFUNC symbol at address %s without " |
| "the ELF support compiled in."), |
| paddress (gdbarch, pc)); |
| } |
| |
| /* See elf_gnu_ifunc_resolve_name for its real implementation. */ |
| |
| static bool |
| stub_gnu_ifunc_resolve_name (const char *function_name, |
| CORE_ADDR *function_address_p) |
| { |
| error (_("GDB cannot resolve STT_GNU_IFUNC symbol \"%s\" without " |
| "the ELF support compiled in."), |
| function_name); |
| } |
| |
| /* See elf_gnu_ifunc_resolver_stop for its real implementation. */ |
| |
| static void |
| stub_gnu_ifunc_resolver_stop (struct breakpoint *b) |
| { |
| internal_error (__FILE__, __LINE__, |
| _("elf_gnu_ifunc_resolver_stop cannot be reached.")); |
| } |
| |
| /* See elf_gnu_ifunc_resolver_return_stop for its real implementation. */ |
| |
| static void |
| stub_gnu_ifunc_resolver_return_stop (struct breakpoint *b) |
| { |
| internal_error (__FILE__, __LINE__, |
| _("elf_gnu_ifunc_resolver_return_stop cannot be reached.")); |
| } |
| |
| /* See elf_gnu_ifunc_fns for its real implementation. */ |
| |
| static const struct gnu_ifunc_fns stub_gnu_ifunc_fns = |
| { |
| stub_gnu_ifunc_resolve_addr, |
| stub_gnu_ifunc_resolve_name, |
| stub_gnu_ifunc_resolver_stop, |
| stub_gnu_ifunc_resolver_return_stop, |
| }; |
| |
| /* A placeholder for &elf_gnu_ifunc_fns. */ |
| |
| const struct gnu_ifunc_fns *gnu_ifunc_fns_p = &stub_gnu_ifunc_fns; |
| |
| |
| |
| /* 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 *abfd) |
| { |
| if (abfd != NULL) |
| return bfd_get_symbol_leading_char (abfd); |
| if (current_program_space->symfile_object_file != NULL) |
| { |
| objfile *objf = current_program_space->symfile_object_file; |
| if (objf->obfd != NULL) |
| return bfd_get_symbol_leading_char (objf->obfd); |
| } |
| return 0; |
| } |
| |
| /* See minsyms.h. */ |
| |
| minimal_symbol_reader::minimal_symbol_reader (struct objfile *obj) |
| : m_objfile (obj), |
| m_msym_bunch (NULL), |
| /* Note that presetting m_msym_bunch_index to BUNCH_SIZE causes the |
| first call to save a minimal symbol to allocate the memory for |
| the first bunch. */ |
| m_msym_bunch_index (BUNCH_SIZE), |
| m_msym_count (0) |
| { |
| } |
| |
| /* 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. */ |
| |
| minimal_symbol_reader::~minimal_symbol_reader () |
| { |
| struct msym_bunch *next; |
| |
| while (m_msym_bunch != NULL) |
| { |
| next = m_msym_bunch->next; |
| xfree (m_msym_bunch); |
| m_msym_bunch = next; |
| } |
| } |
| |
| /* See minsyms.h. */ |
| |
| void |
| minimal_symbol_reader::record (const char *name, CORE_ADDR address, |
| enum minimal_symbol_type ms_type) |
| { |
| int section; |
| |
| switch (ms_type) |
| { |
| case mst_text: |
| case mst_text_gnu_ifunc: |
| case mst_file_text: |
| case mst_solib_trampoline: |
| section = SECT_OFF_TEXT (m_objfile); |
| break; |
| case mst_data: |
| case mst_data_gnu_ifunc: |
| case mst_file_data: |
| section = SECT_OFF_DATA (m_objfile); |
| break; |
| case mst_bss: |
| case mst_file_bss: |
| section = SECT_OFF_BSS (m_objfile); |
| break; |
| default: |
| section = -1; |
| } |
| |
| record_with_info (name, address, ms_type, section); |
| } |
| |
| /* Convert an enumerator of type minimal_symbol_type to its string |
| representation. */ |
| |
| static const char * |
| mst_str (minimal_symbol_type t) |
| { |
| #define MST_TO_STR(x) case x: return #x; |
| switch (t) |
| { |
| MST_TO_STR (mst_unknown); |
| MST_TO_STR (mst_text); |
| MST_TO_STR (mst_text_gnu_ifunc); |
| MST_TO_STR (mst_slot_got_plt); |
| MST_TO_STR (mst_data); |
| MST_TO_STR (mst_bss); |
| MST_TO_STR (mst_abs); |
| MST_TO_STR (mst_solib_trampoline); |
| MST_TO_STR (mst_file_text); |
| MST_TO_STR (mst_file_data); |
| MST_TO_STR (mst_file_bss); |
| |
| default: |
| return "mst_???"; |
| } |
| #undef MST_TO_STR |
| } |
| |
| /* See minsyms.h. */ |
| |
| struct minimal_symbol * |
| minimal_symbol_reader::record_full (gdb::string_view name, |
| bool copy_name, CORE_ADDR address, |
| enum minimal_symbol_type ms_type, |
| int section) |
| { |
| struct msym_bunch *newobj; |
| struct minimal_symbol *msymbol; |
| |
| /* 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 (ms_type == mst_file_text && name[0] == 'g' |
| && (name == GCC_COMPILED_FLAG_SYMBOL |
| || name == GCC2_COMPILED_FLAG_SYMBOL)) |
| return (NULL); |
| |
| /* It's safe to strip the leading char here once, since the name |
| is also stored stripped in the minimal symbol table. */ |
| if (name[0] == get_symbol_leading_char (m_objfile->obfd)) |
| name = name.substr (1); |
| |
| if (ms_type == mst_file_text && startswith (name, "__gnu_compiled")) |
| return (NULL); |
| |
| if (symtab_create_debug >= 2) |
| printf_unfiltered ("Recording minsym: %-21s %18s %4d %.*s\n", |
| mst_str (ms_type), hex_string (address), section, |
| (int) name.size (), name.data ()); |
| |
| if (m_msym_bunch_index == BUNCH_SIZE) |
| { |
| newobj = XCNEW (struct msym_bunch); |
| m_msym_bunch_index = 0; |
| newobj->next = m_msym_bunch; |
| m_msym_bunch = newobj; |
| } |
| msymbol = &m_msym_bunch->contents[m_msym_bunch_index]; |
| msymbol->set_language (language_auto, |
| &m_objfile->per_bfd->storage_obstack); |
| |
| if (copy_name) |
| msymbol->m_name = obstack_strndup (&m_objfile->per_bfd->storage_obstack, |
| name.data (), name.size ()); |
| else |
| msymbol->m_name = name.data (); |
| |
| SET_MSYMBOL_VALUE_ADDRESS (msymbol, address); |
| msymbol->set_section_index (section); |
| |
| MSYMBOL_TYPE (msymbol) = ms_type; |
| |
| /* If we already read minimal symbols for this objfile, then don't |
| ever allocate a new one. */ |
| if (!m_objfile->per_bfd->minsyms_read) |
| { |
| m_msym_bunch_index++; |
| m_objfile->per_bfd->n_minsyms++; |
| } |
| m_msym_count++; |
| return msymbol; |
| } |
| |
| /* Compare two minimal symbols by address and return true if FN1's address |
| is less than FN2's, so that we sort into unsigned numeric order. |
| Within groups with the same address, sort by name. */ |
| |
| static inline bool |
| minimal_symbol_is_less_than (const minimal_symbol &fn1, |
| const minimal_symbol &fn2) |
| { |
| if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) < MSYMBOL_VALUE_RAW_ADDRESS (&fn2)) |
| { |
| return true; /* addr 1 is less than addr 2. */ |
| } |
| else if (MSYMBOL_VALUE_RAW_ADDRESS (&fn1) > MSYMBOL_VALUE_RAW_ADDRESS (&fn2)) |
| { |
| return false; /* addr 1 is greater than addr 2. */ |
| } |
| else |
| /* addrs are equal: sort by name */ |
| { |
| const char *name1 = fn1.linkage_name (); |
| const char *name2 = fn2.linkage_name (); |
| |
| if (name1 && name2) /* both have names */ |
| return strcmp (name1, name2) < 0; |
| else if (name2) |
| return true; /* fn1 has no name, so it is "less". */ |
| else if (name1) /* fn2 has no name, so it is "less". */ |
| return false; |
| else |
| return false; /* Neither has a name, so they're equal. */ |
| } |
| } |
| |
| /* 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. |
| |
| 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 (MSYMBOL_VALUE_RAW_ADDRESS (copyfrom) |
| == MSYMBOL_VALUE_RAW_ADDRESS ((copyfrom + 1)) |
| && (copyfrom->section_index () |
| == (copyfrom + 1)->section_index ()) |
| && strcmp (copyfrom->linkage_name (), |
| (copyfrom + 1)->linkage_name ()) == 0) |
| { |
| 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); |
| } |
| |
| static void |
| clear_minimal_symbol_hash_tables (struct objfile *objfile) |
| { |
| for (size_t i = 0; i < MINIMAL_SYMBOL_HASH_SIZE; i++) |
| { |
| objfile->per_bfd->msymbol_hash[i] = 0; |
| objfile->per_bfd->msymbol_demangled_hash[i] = 0; |
| } |
| } |
| |
| /* This struct is used to store values we compute for msymbols on the |
| background threads but don't need to keep around long term. */ |
| struct computed_hash_values |
| { |
| /* Length of the linkage_name of the symbol. */ |
| size_t name_length; |
| /* Hash code (using fast_hash) of the linkage_name. */ |
| hashval_t mangled_name_hash; |
| /* The msymbol_hash of the linkage_name. */ |
| unsigned int minsym_hash; |
| /* The msymbol_hash of the search_name. */ |
| unsigned int minsym_demangled_hash; |
| }; |
| |
| /* 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, |
| const std::vector<computed_hash_values>& hash_values) |
| { |
| int i; |
| struct minimal_symbol *msym; |
| |
| /* (Re)insert the actual entries. */ |
| int mcount = objfile->per_bfd->minimal_symbol_count; |
| for ((i = 0, |
| msym = objfile->per_bfd->msymbols.get ()); |
| i < mcount; |
| i++, msym++) |
| { |
| msym->hash_next = 0; |
| add_minsym_to_hash_table (msym, objfile->per_bfd->msymbol_hash, |
| hash_values[i].minsym_hash); |
| |
| msym->demangled_hash_next = 0; |
| if (msym->search_name () != msym->linkage_name ()) |
| add_minsym_to_demangled_hash_table |
| (msym, objfile, hash_values[i].minsym_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. */ |
| |
| void |
| minimal_symbol_reader::install () |
| { |
| int mcount; |
| struct msym_bunch *bunch; |
| struct minimal_symbol *msymbols; |
| int alloc_count; |
| |
| if (m_objfile->per_bfd->minsyms_read) |
| return; |
| |
| if (m_msym_count > 0) |
| { |
| if (symtab_create_debug) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "Installing %d minimal symbols of objfile %s.\n", |
| m_msym_count, objfile_name (m_objfile)); |
| } |
| |
| /* Allocate enough space, 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 = m_msym_count + m_objfile->per_bfd->minimal_symbol_count; |
| gdb::unique_xmalloc_ptr<minimal_symbol> |
| msym_holder (XNEWVEC (minimal_symbol, alloc_count)); |
| msymbols = msym_holder.get (); |
| |
| /* Copy in the existing minimal symbols, if there are any. */ |
| |
| if (m_objfile->per_bfd->minimal_symbol_count) |
| memcpy (msymbols, m_objfile->per_bfd->msymbols.get (), |
| m_objfile->per_bfd->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 = m_objfile->per_bfd->minimal_symbol_count; |
| |
| for (bunch = m_msym_bunch; bunch != NULL; bunch = bunch->next) |
| { |
| memcpy (&msymbols[mcount], &bunch->contents[0], |
| m_msym_bunch_index * sizeof (struct minimal_symbol)); |
| mcount += m_msym_bunch_index; |
| m_msym_bunch_index = BUNCH_SIZE; |
| } |
| |
| /* Sort the minimal symbols by address. */ |
| |
| std::sort (msymbols, msymbols + mcount, minimal_symbol_is_less_than); |
| |
| /* Compact out any duplicates, and free up whatever space we are |
| no longer using. */ |
| |
| mcount = compact_minimal_symbols (msymbols, mcount, m_objfile); |
| msym_holder.reset (XRESIZEVEC (struct minimal_symbol, |
| msym_holder.release (), |
| mcount)); |
| |
| /* Attach the minimal symbol table to the specified objfile. |
| The strings themselves are also located in the storage_obstack |
| of this objfile. */ |
| |
| if (m_objfile->per_bfd->minimal_symbol_count != 0) |
| clear_minimal_symbol_hash_tables (m_objfile); |
| |
| m_objfile->per_bfd->minimal_symbol_count = mcount; |
| m_objfile->per_bfd->msymbols = std::move (msym_holder); |
| |
| #if CXX_STD_THREAD |
| /* Mutex that is used when modifying or accessing the demangled |
| hash table. */ |
| std::mutex demangled_mutex; |
| #endif |
| |
| std::vector<computed_hash_values> hash_values (mcount); |
| |
| msymbols = m_objfile->per_bfd->msymbols.get (); |
| gdb::parallel_for_each |
| (&msymbols[0], &msymbols[mcount], |
| [&] (minimal_symbol *start, minimal_symbol *end) |
| { |
| for (minimal_symbol *msym = start; msym < end; ++msym) |
| { |
| size_t idx = msym - msymbols; |
| hash_values[idx].name_length = strlen (msym->linkage_name ()); |
| if (!msym->name_set) |
| { |
| /* This will be freed later, by compute_and_set_names. */ |
| gdb::unique_xmalloc_ptr<char> demangled_name |
| = symbol_find_demangled_name (msym, msym->linkage_name ()); |
| msym->set_demangled_name |
| (demangled_name.release (), |
| &m_objfile->per_bfd->storage_obstack); |
| msym->name_set = 1; |
| } |
| /* This mangled_name_hash computation has to be outside of |
| the name_set check, or compute_and_set_names below will |
| be called with an invalid hash value. */ |
| hash_values[idx].mangled_name_hash |
| = fast_hash (msym->linkage_name (), |
| hash_values[idx].name_length); |
| hash_values[idx].minsym_hash |
| = msymbol_hash (msym->linkage_name ()); |
| /* We only use this hash code if the search name differs |
| from the linkage name. See the code in |
| build_minimal_symbol_hash_tables. */ |
| if (msym->search_name () != msym->linkage_name ()) |
| hash_values[idx].minsym_demangled_hash |
| = search_name_hash (msym->language (), msym->search_name ()); |
| } |
| { |
| /* To limit how long we hold the lock, we only acquire it here |
| and not while we demangle the names above. */ |
| #if CXX_STD_THREAD |
| std::lock_guard<std::mutex> guard (demangled_mutex); |
| #endif |
| for (minimal_symbol *msym = start; msym < end; ++msym) |
| { |
| size_t idx = msym - msymbols; |
| msym->compute_and_set_names |
| (gdb::string_view (msym->linkage_name (), |
| hash_values[idx].name_length), |
| false, |
| m_objfile->per_bfd, |
| hash_values[idx].mangled_name_hash); |
| } |
| } |
| }); |
| |
| build_minimal_symbol_hash_tables (m_objfile, hash_values); |
| } |
| } |
| |
| /* 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. */ |
| |
| static struct minimal_symbol * |
| lookup_solib_trampoline_symbol_by_pc (CORE_ADDR pc) |
| { |
| bound_minimal_symbol msymbol |
| = lookup_minimal_symbol_by_pc_section (pc, NULL, |
| lookup_msym_prefer::TRAMPOLINE); |
| |
| if (msymbol.minsym != NULL |
| && MSYMBOL_TYPE (msymbol.minsym) == mst_solib_trampoline) |
| return msymbol.minsym; |
| 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 (struct frame_info *frame, CORE_ADDR pc) |
| { |
| struct minimal_symbol *tsymbol = lookup_solib_trampoline_symbol_by_pc (pc); |
| |
| if (tsymbol != NULL) |
| { |
| for (objfile *objfile : current_program_space->objfiles ()) |
| { |
| for (minimal_symbol *msymbol : objfile->msymbols ()) |
| { |
| /* Also handle minimal symbols pointing to function |
| descriptors. */ |
| if ((MSYMBOL_TYPE (msymbol) == mst_text |
| || MSYMBOL_TYPE (msymbol) == mst_text_gnu_ifunc |
| || MSYMBOL_TYPE (msymbol) == mst_data |
| || MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc) |
| && strcmp (msymbol->linkage_name (), |
| tsymbol->linkage_name ()) == 0) |
| { |
| CORE_ADDR func; |
| |
| /* Ignore data symbols that are not function |
| descriptors. */ |
| if (msymbol_is_function (objfile, msymbol, &func)) |
| return func; |
| } |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* See minsyms.h. */ |
| |
| CORE_ADDR |
| minimal_symbol_upper_bound (struct bound_minimal_symbol minsym) |
| { |
| short section; |
| struct obj_section *obj_section; |
| CORE_ADDR result; |
| struct minimal_symbol *iter, *msymbol; |
| |
| gdb_assert (minsym.minsym != NULL); |
| |
| /* If the minimal symbol has a size, use it. Otherwise use the |
| lesser of the next minimal symbol in the same section, or the end |
| of the section, as the end of the function. */ |
| |
| if (MSYMBOL_SIZE (minsym.minsym) != 0) |
| return BMSYMBOL_VALUE_ADDRESS (minsym) + MSYMBOL_SIZE (minsym.minsym); |
| |
| /* 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. */ |
| |
| struct minimal_symbol *past_the_end |
| = (minsym.objfile->per_bfd->msymbols.get () |
| + minsym.objfile->per_bfd->minimal_symbol_count); |
| msymbol = minsym.minsym; |
| section = msymbol->section_index (); |
| for (iter = msymbol + 1; iter != past_the_end; ++iter) |
| { |
| if ((MSYMBOL_VALUE_RAW_ADDRESS (iter) |
| != MSYMBOL_VALUE_RAW_ADDRESS (msymbol)) |
| && iter->section_index () == section) |
| break; |
| } |
| |
| obj_section = minsym.obj_section (); |
| if (iter != past_the_end |
| && (MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter) |
| < obj_section->endaddr ())) |
| result = MSYMBOL_VALUE_ADDRESS (minsym.objfile, iter); |
| else |
| /* We got the start address from the last msymbol in the objfile. |
| So the end address is the end of the section. */ |
| result = obj_section->endaddr (); |
| |
| return result; |
| } |