diff options
Diffstat (limited to 'ld/plugin.c')
| -rw-r--r-- | ld/plugin.c | 795 |
1 files changed, 795 insertions, 0 deletions
diff --git a/ld/plugin.c b/ld/plugin.c new file mode 100644 index 0000000..b484bd0 --- /dev/null +++ b/ld/plugin.c @@ -0,0 +1,795 @@ +/* Plugin control for the GNU linker. + Copyright 2010 Free Software Foundation, Inc. + + This file is part of the GNU Binutils. + + 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, write to the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, + MA 02110-1301, USA. */ + +#include "sysdep.h" +#include "libiberty.h" +#include "bfd.h" +#include "bfdlink.h" +#include "bfdver.h" +#include "ld.h" +#include "ldmain.h" +#include "ldmisc.h" +#include "ldexp.h" +#include "ldlang.h" +#include "ldfile.h" +#include "plugin.h" +#include "plugin-api.h" +#include "elf-bfd.h" + +/* The suffix to append to the name of the real (claimed) object file + when generating a dummy BFD to hold the IR symbols sent from the + plugin. */ +#define IRONLY_SUFFIX ".ironly\004" + +/* This is sizeof an array of chars, not sizeof a const char *. We + also have to avoid inadvertently counting the trailing NUL. */ +#define IRONLY_SUFFIX_LEN (sizeof (IRONLY_SUFFIX) - 1) + +/* Stores a single argument passed to a plugin. */ +typedef struct plugin_arg +{ + struct plugin_arg *next; + const char *arg; +} plugin_arg_t; + +/* Holds all details of a single plugin. */ +typedef struct plugin +{ + /* Next on the list of plugins, or NULL at end of chain. */ + struct plugin *next; + /* The argument string given to --plugin. */ + const char *name; + /* The shared library handle returned by dlopen. */ + void *dlhandle; + /* The list of argument string given to --plugin-opt. */ + plugin_arg_t *args; + /* Number of args in the list, for convenience. */ + size_t n_args; + /* The plugin's event handlers. */ + ld_plugin_claim_file_handler claim_file_handler; + ld_plugin_all_symbols_read_handler all_symbols_read_handler; + ld_plugin_cleanup_handler cleanup_handler; + /* TRUE if the cleanup handlers have been called. */ + bfd_boolean cleanup_done; +} plugin_t; + +/* The master list of all plugins. */ +static plugin_t *plugins_list = NULL; + +/* We keep a tail pointer for easy linking on the end. */ +static plugin_t **plugins_tail_chain_ptr = &plugins_list; + +/* The last plugin added to the list, for receiving args. */ +static plugin_t *last_plugin = NULL; + +/* The tail of the arg chain of the last plugin added to the list. */ +static plugin_arg_t **last_plugin_args_tail_chain_ptr = NULL; + +/* The plugin which is currently having a callback executed. */ +static plugin_t *called_plugin = NULL; + +/* Last plugin to cause an error, if any. */ +static const char *error_plugin = NULL; + +/* A hash table that records symbols referenced by non-IR files. Used + at get_symbols time to determine whether any prevailing defs from + IR files are referenced only from other IR files, so tthat we can + we can distinguish the LDPR_PREVAILING_DEF and LDPR_PREVAILING_DEF_IRONLY + cases when establishing symbol resolutions. */ +static struct bfd_hash_table *non_ironly_hash = NULL; + +/* Set at all symbols read time, to avoid recursively offering the plugin + its own newly-added input files and libs to claim. */ +static bfd_boolean no_more_claiming = FALSE; + +/* If the --allow-multiple-definition command-line option is active, we + have to disable it so that BFD always calls our hook, and simulate the + effect (when not resolving IR vs. real symbols) ourselves by ensuring + TRUE is returned from the hook. */ +static bfd_boolean plugin_cached_allow_multiple_defs = FALSE; + +/* List of tags to set in the constant leading part of the tv array. */ +static const enum ld_plugin_tag tv_header_tags[] = +{ + LDPT_MESSAGE, + LDPT_API_VERSION, + LDPT_GNU_LD_VERSION, + LDPT_LINKER_OUTPUT, + LDPT_OUTPUT_NAME, + LDPT_REGISTER_CLAIM_FILE_HOOK, + LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK, + LDPT_REGISTER_CLEANUP_HOOK, + LDPT_ADD_SYMBOLS, + LDPT_GET_INPUT_FILE, + LDPT_RELEASE_INPUT_FILE, + LDPT_GET_SYMBOLS, + LDPT_ADD_INPUT_FILE, + LDPT_ADD_INPUT_LIBRARY, + LDPT_SET_EXTRA_LIBRARY_PATH +}; + +/* How many entries in the constant leading part of the tv array. */ +static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags); + +/* Helper function for exiting with error status. */ +static int +set_plugin_error (const char *plugin) +{ + error_plugin = plugin; + return -1; +} + +/* Test if an error occurred. */ +static bfd_boolean +plugin_error_p (void) +{ + return error_plugin != NULL; +} + +/* Return name of plugin which caused an error if any. */ +const char *plugin_error_plugin (void) +{ + return error_plugin ? error_plugin : _("<no plugin>"); +} + +/* Handle -plugin arg: find and load plugin, or return error. */ +int plugin_opt_plugin (const char *plugin) +{ + plugin_t *newplug; + + newplug = xmalloc (sizeof *newplug); + memset (newplug, 0, sizeof *newplug); + newplug->name = plugin; + newplug->dlhandle = dlopen (plugin, RTLD_NOW); + if (!newplug->dlhandle) + return set_plugin_error (plugin); + + /* Chain on end, so when we run list it is in command-line order. */ + *plugins_tail_chain_ptr = newplug; + plugins_tail_chain_ptr = &newplug->next; + + /* Record it as current plugin for receiving args. */ + last_plugin = newplug; + last_plugin_args_tail_chain_ptr = &newplug->args; + return 0; +} + +/* Accumulate option arguments for last-loaded plugin, or return + error if none. */ +int plugin_opt_plugin_arg (const char *arg) +{ + plugin_arg_t *newarg; + + if (!last_plugin) + return set_plugin_error (_("<no plugin>")); + + newarg = xmalloc (sizeof *newarg); + newarg->arg = arg; + newarg->next = NULL; + + /* Chain on end to preserve command-line order. */ + *last_plugin_args_tail_chain_ptr = newarg; + last_plugin_args_tail_chain_ptr = &newarg->next; + last_plugin->n_args++; + return 0; +} + +/* Create a dummy BFD. */ +bfd * +plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate) +{ + asection *sec; + bfd *abfd = bfd_create ( + concat (name, IRONLY_SUFFIX, (const char *)NULL), + srctemplate); + bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate)); + bfd_make_writable (abfd); + /* Create a minimal set of sections to own the symbols. */ + sec = bfd_make_section_old_way (abfd, ".text"); + bfd_set_section_flags (abfd, sec, + SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY + | SEC_ALLOC | SEC_LOAD | SEC_KEEP); + sec->output_section = sec; + sec->output_offset = 0; + return abfd; +} + +/* Check if the BFD is an IR dummy. */ +bfd_boolean +is_ir_dummy_bfd (const bfd *abfd) +{ + size_t namlen = strlen (abfd->filename); + if (namlen < IRONLY_SUFFIX_LEN) + return FALSE; + return !strcmp (abfd->filename + namlen - IRONLY_SUFFIX_LEN, IRONLY_SUFFIX); +} + +/* Helpers to convert between BFD and GOLD symbol formats. */ +static enum ld_plugin_status +asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym, + const struct ld_plugin_symbol *ldsym) +{ + flagword flags = BSF_NO_FLAGS; + struct bfd_section *section; + + asym->the_bfd = abfd; + asym->name = ldsym->version + ? concat (ldsym->name, "@", ldsym->version, NULL) + : ldsym->name; + asym->value = 0; + switch (ldsym->def) + { + case LDPK_WEAKDEF: + flags = BSF_WEAK; + /* FALLTHRU */ + case LDPK_DEF: + flags |= BSF_GLOBAL; + section = bfd_get_section_by_name (abfd, ".text"); + break; + + case LDPK_WEAKUNDEF: + flags = BSF_WEAK; + /* FALLTHRU */ + case LDPK_UNDEF: + section = bfd_und_section_ptr; + break; + + case LDPK_COMMON: + flags = BSF_GLOBAL; + section = bfd_com_section_ptr; + asym->value = ldsym->size; + break; + + default: + return LDPS_ERR; + } + asym->flags = flags; + asym->section = section; + + /* Visibility only applies on ELF targets. */ + if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) + { + elf_symbol_type *elfsym = elf_symbol_from (abfd, asym); + if (!elfsym) + einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!"), asym->name); + elfsym->internal_elf_sym.st_other &= ~3; + elfsym->internal_elf_sym.st_other |= ldsym->visibility; + } + + return LDPS_OK; +} + +/* Register a claim-file handler. */ +static enum ld_plugin_status +register_claim_file (ld_plugin_claim_file_handler handler) +{ + ASSERT (called_plugin); + called_plugin->claim_file_handler = handler; + return LDPS_OK; +} + +/* Register an all-symbols-read handler. */ +static enum ld_plugin_status +register_all_symbols_read (ld_plugin_all_symbols_read_handler handler) +{ + ASSERT (called_plugin); + called_plugin->all_symbols_read_handler = handler; + return LDPS_OK; +} + +/* Register a cleanup handler. */ +static enum ld_plugin_status +register_cleanup (ld_plugin_cleanup_handler handler) +{ + ASSERT (called_plugin); + called_plugin->cleanup_handler = handler; + return LDPS_OK; +} + +/* Add symbols from a plugin-claimed input file. */ +static enum ld_plugin_status +add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms) +{ + asymbol **symptrs; + bfd *abfd = handle; + int n; + ASSERT (called_plugin); + symptrs = xmalloc (nsyms * sizeof *symptrs); + for (n = 0; n < nsyms; n++) + { + enum ld_plugin_status rv; + asymbol *bfdsym = bfd_make_empty_symbol (abfd); + symptrs[n] = bfdsym; + rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n); + if (rv != LDPS_OK) + return rv; + } + bfd_set_symtab (abfd, symptrs, nsyms); + return LDPS_OK; +} + +/* Get the input file information with an open (possibly re-opened) + file descriptor. */ +static enum ld_plugin_status +get_input_file (const void *handle, struct ld_plugin_input_file *file) +{ + ASSERT (called_plugin); + handle = handle; + file = file; + return LDPS_ERR; +} + +/* Release the input file. */ +static enum ld_plugin_status +release_input_file (const void *handle) +{ + ASSERT (called_plugin); + handle = handle; + return LDPS_ERR; +} + +/* Get the symbol resolution info for a plugin-claimed input file. */ +static enum ld_plugin_status +get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms) +{ + const bfd *abfd = handle; + int n; + ASSERT (called_plugin); + for (n = 0; n < nsyms; n++) + { + struct bfd_link_hash_entry *blhe; + bfd_boolean ironly; + + blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name, + FALSE, FALSE, TRUE); + if (!blhe) + { + syms[n].resolution = LDPR_UNKNOWN; + continue; + } + + /* Determine resolution from blhe type and symbol's original type. */ + if (blhe->type == bfd_link_hash_undefined + || blhe->type == bfd_link_hash_undefweak) + { + syms[n].resolution = LDPR_UNDEF; + continue; + } + if (blhe->type != bfd_link_hash_defined + && blhe->type != bfd_link_hash_defweak + && blhe->type != bfd_link_hash_common) + { + /* We should not have a new, indirect or warning symbol here. */ + einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)", + called_plugin->name, blhe->type); + } + + /* We need to know if the sym is referenced from non-IR files. */ + ironly = !bfd_hash_lookup (non_ironly_hash, syms[n].name, FALSE, FALSE); + + /* If it was originally undefined or common, then it has been + resolved; determine how. */ + if (syms[n].def == LDPK_UNDEF || syms[n].def == LDPK_WEAKUNDEF + || syms[n].def == LDPK_COMMON) + { + asection *owner_sec = (syms[n].def == LDPK_COMMON) + ? blhe->u.c.p->section + : blhe->u.def.section; + if (owner_sec->owner == link_info.output_bfd) + syms[n].resolution = LDPR_RESOLVED_EXEC; + else if (owner_sec->owner == abfd) + syms[n].resolution = (ironly) + ? LDPR_PREVAILING_DEF_IRONLY + : LDPR_PREVAILING_DEF; + else if (is_ir_dummy_bfd (owner_sec->owner)) + syms[n].resolution = LDPR_RESOLVED_IR; + else if (owner_sec->owner->flags & DYNAMIC) + syms[n].resolution = LDPR_RESOLVED_DYN; + else + syms[n].resolution = LDPR_RESOLVED_EXEC; + continue; + } + + /* Was originally def, or weakdef. Does it prevail? If the + owner is the original dummy bfd that supplied it, then this + is the definition that has prevailed. */ + if (blhe->u.def.section->owner == link_info.output_bfd) + syms[n].resolution = LDPR_PREEMPTED_REG; + else if (blhe->u.def.section->owner == abfd) + { + syms[n].resolution = (ironly) + ? LDPR_PREVAILING_DEF_IRONLY + : LDPR_PREVAILING_DEF; + continue; + } + + /* Was originally def, weakdef, or common, but has been pre-empted. */ + syms[n].resolution = is_ir_dummy_bfd (blhe->u.def.section->owner) + ? LDPR_PREEMPTED_IR + : LDPR_PREEMPTED_REG; + } + return LDPS_OK; +} + +/* Add a new (real) input file generated by a plugin. */ +static enum ld_plugin_status +add_input_file (const char *pathname) +{ + ASSERT (called_plugin); + if (!lang_add_input_file (pathname, lang_input_file_is_file_enum, NULL)) + return LDPS_ERR; + return LDPS_OK; +} + +/* Add a new (real) library required by a plugin. */ +static enum ld_plugin_status +add_input_library (const char *pathname) +{ + ASSERT (called_plugin); + if (!lang_add_input_file (pathname, lang_input_file_is_l_enum, NULL)) + return LDPS_ERR; + return LDPS_OK; +} + +/* Set the extra library path to be used by libraries added via + add_input_library. */ +static enum ld_plugin_status +set_extra_library_path (const char *path) +{ + ASSERT (called_plugin); + ldfile_add_library_path (path, FALSE); + return LDPS_OK; +} + +/* Issue a diagnostic message from a plugin. */ +static enum ld_plugin_status +message (int level, const char *format, ...) +{ + va_list args; + va_start (args, format); + + switch (level) + { + case LDPL_INFO: + vfinfo (stdout, format, args, FALSE); + break; + case LDPL_WARNING: + vfinfo (stdout, format, args, TRUE); + break; + case LDPL_FATAL: + case LDPL_ERROR: + default: + { + char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%F" : "%X", + format, NULL)); + vfinfo (stderr, newfmt, args, TRUE); + } + break; + } + + va_end (args); + return LDPS_OK; +} + +/* Helper to size leading part of tv array and set it up. */ +static size_t +set_tv_header (struct ld_plugin_tv *tv) +{ + size_t i; + + /* Version info. */ + static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL); + static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100; + + if (!tv) + return tv_header_size; + + for (i = 0; i < tv_header_size; i++) + { + tv[i].tv_tag = tv_header_tags[i]; +#define TVU(x) tv[i].tv_u.tv_ ## x + switch (tv[i].tv_tag) + { + case LDPT_MESSAGE: + TVU(message) = message; + break; + case LDPT_API_VERSION: + TVU(val) = LD_PLUGIN_API_VERSION; + break; + case LDPT_GNU_LD_VERSION: + TVU(val) = major * 100 + minor; + break; + case LDPT_LINKER_OUTPUT: + TVU(val) = link_info.relocatable ? LDPO_REL + : (link_info.shared ? LDPO_DYN : LDPO_EXEC); + break; + case LDPT_OUTPUT_NAME: + TVU(string) = output_filename; + break; + case LDPT_REGISTER_CLAIM_FILE_HOOK: + TVU(register_claim_file) = register_claim_file; + break; + case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: + TVU(register_all_symbols_read) = register_all_symbols_read; + break; + case LDPT_REGISTER_CLEANUP_HOOK: + TVU(register_cleanup) = register_cleanup; + break; + case LDPT_ADD_SYMBOLS: + TVU(add_symbols) = add_symbols; + break; + case LDPT_GET_INPUT_FILE: + TVU(get_input_file) = get_input_file; + break; + case LDPT_RELEASE_INPUT_FILE: + TVU(release_input_file) = release_input_file; + break; + case LDPT_GET_SYMBOLS: + TVU(get_symbols) = get_symbols; + break; + case LDPT_ADD_INPUT_FILE: + TVU(add_input_file) = add_input_file; + break; + case LDPT_ADD_INPUT_LIBRARY: + TVU(add_input_library) = add_input_library; + break; + case LDPT_SET_EXTRA_LIBRARY_PATH: + TVU(set_extra_library_path) = set_extra_library_path; + break; + default: + /* Added a new entry to the array without adding + a new case to set up its value is a bug. */ + FAIL (); + } +#undef TVU + } + return tv_header_size; +} + +/* Append the per-plugin args list and trailing LDPT_NULL to tv. */ +static void +set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv) +{ + plugin_arg_t *arg = plugin->args; + while (arg) + { + tv->tv_tag = LDPT_OPTION; + tv->tv_u.tv_string = arg->arg; + arg = arg->next; + tv++; + } + tv->tv_tag = LDPT_NULL; + tv->tv_u.tv_val = 0; +} + +/* Load up and initialise all plugins after argument parsing. */ +int plugin_load_plugins (void) +{ + struct ld_plugin_tv *my_tv; + unsigned int max_args = 0; + plugin_t *curplug = plugins_list; + + /* If there are no plugins, we need do nothing this run. */ + if (!curplug) + return 0; + + /* First pass over plugins to find max # args needed so that we + can size and allocate the tv array. */ + while (curplug) + { + if (curplug->n_args > max_args) + max_args = curplug->n_args; + curplug = curplug->next; + } + + /* Allocate tv array and initialise constant part. */ + my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv); + set_tv_header (my_tv); + + /* Pass over plugins again, activating them. */ + curplug = plugins_list; + while (curplug) + { + enum ld_plugin_status rv; + ld_plugin_onload onloadfn = dlsym (curplug->dlhandle, "onload"); + if (!onloadfn) + onloadfn = dlsym (curplug->dlhandle, "_onload"); + if (!onloadfn) + return set_plugin_error (curplug->name); + set_tv_plugin_args (curplug, &my_tv[tv_header_size]); + called_plugin = curplug; + rv = (*onloadfn) (my_tv); + called_plugin = NULL; + if (rv != LDPS_OK) + return set_plugin_error (curplug->name); + curplug = curplug->next; + } + + /* Since plugin(s) inited ok, assume they're going to want symbol + resolutions, which needs us to track which symbols are referenced + by non-IR files using the linker's notice callback. */ + link_info.notice_all = TRUE; + + return 0; +} + +/* Call 'claim file' hook for all plugins. */ +int +plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed) +{ + plugin_t *curplug = plugins_list; + *claimed = FALSE; + if (no_more_claiming) + return 0; + while (curplug && !*claimed) + { + if (curplug->claim_file_handler) + { + enum ld_plugin_status rv; + called_plugin = curplug; + rv = (*curplug->claim_file_handler) (file, claimed); + called_plugin = NULL; + if (rv != LDPS_OK) + set_plugin_error (curplug->name); + } + curplug = curplug->next; + } + return plugin_error_p () ? -1 : 0; +} + +/* Call 'all symbols read' hook for all plugins. */ +int +plugin_call_all_symbols_read (void) +{ + plugin_t *curplug = plugins_list; + + /* Disable any further file-claiming. */ + no_more_claiming = TRUE; + + /* If --allow-multiple-definition is in effect, we need to disable it, + as the plugin infrastructure relies on the multiple_definition + callback to swap out the dummy IR-only BFDs for new real ones + when it starts opening the files added during this callback. */ + plugin_cached_allow_multiple_defs = link_info.allow_multiple_definition; + link_info.allow_multiple_definition = FALSE; + + while (curplug) + { + if (curplug->all_symbols_read_handler) + { + enum ld_plugin_status rv; + called_plugin = curplug; + rv = (*curplug->all_symbols_read_handler) (); + called_plugin = NULL; + if (rv != LDPS_OK) + set_plugin_error (curplug->name); + } + curplug = curplug->next; + } + return plugin_error_p () ? -1 : 0; +} + +/* Call 'cleanup' hook for all plugins. */ +int +plugin_call_cleanup (void) +{ + plugin_t *curplug = plugins_list; + while (curplug) + { + if (curplug->cleanup_handler && !curplug->cleanup_done) + { + enum ld_plugin_status rv; + curplug->cleanup_done = TRUE; + called_plugin = curplug; + rv = (*curplug->cleanup_handler) (); + called_plugin = NULL; + if (rv != LDPS_OK) + set_plugin_error (curplug->name); + dlclose (curplug->dlhandle); + } + curplug = curplug->next; + } + return plugin_error_p () ? -1 : 0; +} + +/* Lazily init the non_ironly hash table. */ +static void +init_non_ironly_hash (void) +{ + if (non_ironly_hash == NULL) + { + non_ironly_hash = + (struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table)); + if (!bfd_hash_table_init_n (non_ironly_hash, + bfd_hash_newfunc, + sizeof (struct bfd_hash_entry), + 61)) + einfo (_("%P%F: bfd_hash_table_init failed: %E\n")); + } +} + +/* To determine which symbols should be resolved LDPR_PREVAILING_DEF + and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as + the linker adds them to the linker hash table. If we see a symbol + being referenced from a non-IR file, we add it to the non_ironly hash + table. If we can't find it there at get_symbols time, we know that + it was referenced only by IR files. We have to notice_all symbols, + because we won't necessarily know until later which ones will be + contributed by IR files. */ +bfd_boolean +plugin_notice (struct bfd_link_info *info ATTRIBUTE_UNUSED, + const char *name, bfd *abfd, + asection *section, bfd_vma value ATTRIBUTE_UNUSED) +{ + bfd_boolean is_ref = bfd_is_und_section (section); + bfd_boolean is_dummy = is_ir_dummy_bfd (abfd); + init_non_ironly_hash (); + /* We only care about refs, not defs, indicated by section pointing + to the undefined section (according to the bfd linker notice callback + interface definition). */ + if (is_ref && !is_dummy) + { + /* This is a ref from a non-IR file, so note the ref'd symbol + in the non-IR-only hash. */ + if (!bfd_hash_lookup (non_ironly_hash, name, TRUE, TRUE)) + einfo (_("%P%X: %s: hash table failure adding symbol %s"), + abfd->filename, name); + } + else if (!is_ref && is_dummy) + { + /* No further processing since this is a def from an IR dummy BFD. */ + return FALSE; + } + + /* Continue with cref/nocrossref/trace-sym processing. */ + return TRUE; +} + +/* When we add new object files to the link at all symbols read time, + these contain the real code and symbols generated from the IR files, + and so duplicate all the definitions already supplied by the dummy + IR-only BFDs that we created at claim files time. We use the linker's + multiple-definitions callback hook to fix up the clash, discarding + the symbol from the IR-only BFD in favour of the symbol from the + real BFD. We return true if this was not-really-a-clash because + we've fixed it up, or anyway if --allow-multiple-definition was in + effect (before we disabled it to ensure we got called back). */ +bfd_boolean +plugin_multiple_definition (struct bfd_link_info *info, const char *name, + bfd *obfd, asection *osec ATTRIBUTE_UNUSED, + bfd_vma oval ATTRIBUTE_UNUSED, + bfd *nbfd, asection *nsec, bfd_vma nval) +{ + if (is_ir_dummy_bfd (obfd)) + { + struct bfd_link_hash_entry *blhe = bfd_link_hash_lookup (info->hash, + name, FALSE, FALSE, FALSE); + if (!blhe) + einfo (_("%P%X: %s: can't find IR symbol '%s'"), nbfd->filename, + name); + else if (blhe->type != bfd_link_hash_defined) + einfo (_("%P%x: %s: bad IR symbol type %d"), name, blhe->type); + /* Replace it with new details. */ + blhe->u.def.section = nsec; + blhe->u.def.value = nval; + return TRUE; + } + return plugin_cached_allow_multiple_defs; +} |