diff options
Diffstat (limited to 'ld/plugin.c')
| -rw-r--r-- | ld/plugin.c | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/ld/plugin.c b/ld/plugin.c new file mode 100644 index 0000000..f02a97f --- /dev/null +++ b/ld/plugin.c @@ -0,0 +1,1042 @@ +/* Plugin control for the GNU linker. + Copyright (C) 2010-2014 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" +#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) +#include <windows.h> +#endif + +/* Report plugin symbols. */ +bfd_boolean report_plugin_symbols; + +/* 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. For cosmetic use only; appears in maps, crefs etc. */ +#define IRONLY_SUFFIX " (symbol from plugin)" + +/* 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; + +/* State of linker "notice" interface before we poked at it. */ +static bfd_boolean orig_notice_all; + +/* Original linker callbacks, and the plugin version. */ +static const struct bfd_link_callbacks *orig_callbacks; +static struct bfd_link_callbacks plugin_callbacks; + +/* Set at all symbols read time, to avoid recursively offering the plugin + its own newly-added input files and libs to claim. */ +bfd_boolean no_more_claiming = 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_GET_SYMBOLS_V2, + 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); + +/* Forward references. */ +static bfd_boolean plugin_notice (struct bfd_link_info *, + struct bfd_link_hash_entry *, + struct bfd_link_hash_entry *, + bfd *, asection *, bfd_vma, flagword); + +#if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) + +#define RTLD_NOW 0 /* Dummy value. */ + +static void * +dlopen (const char *file, int mode ATTRIBUTE_UNUSED) +{ + return LoadLibrary (file); +} + +static void * +dlsym (void *handle, const char *name) +{ + return GetProcAddress (handle, name); +} + +static int +dlclose (void *handle) +{ + FreeLibrary (handle); + return 0; +} + +#endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */ + +#ifndef HAVE_DLFCN_H +static const char * +dlerror (void) +{ + return ""; +} +#endif + +/* 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. */ +void +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) + einfo (_("%P%F: %s: error loading plugin: %s\n"), plugin, dlerror ()); + + /* 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; +} + +/* 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>")); + + /* Ignore -pass-through= from GCC driver. */ + if (*arg == '-') + { + const char *p = arg + 1; + + if (*p == '-') + ++p; + if (strncmp (p, "pass-through=", 13) == 0) + return 0; + } + + 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) +{ + bfd *abfd; + + bfd_use_reserved_id = 1; + abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *) NULL), + srctemplate); + if (abfd != NULL) + { + abfd->flags |= BFD_LINKER_CREATED | BFD_PLUGIN; + bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate)); + bfd_set_gp_size (abfd, bfd_get_gp_size (srctemplate)); + if (bfd_make_writable (abfd) + && bfd_copy_private_bfd_data (srctemplate, abfd)) + { + flagword flags; + + /* Create section to own the symbols. */ + flags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY + | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE); + if (bfd_make_section_anyway_with_flags (abfd, ".text", flags)) + return abfd; + } + } + einfo (_("could not create dummy IR bfd: %F%E\n")); + return NULL; +} + +/* Check if the BFD passed in is an IR dummy object file. */ +static inline bfd_boolean +is_ir_dummy_bfd (const bfd *abfd) +{ + /* ABFD can sometimes legitimately be NULL, e.g. when called from one + of the linker callbacks for a symbol in the *ABS* or *UND* sections. */ + return abfd != NULL && (abfd->flags & BFD_PLUGIN) != 0; +} + +/* 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, (const char *) NULL) + : ldsym->name); + asym->value = 0; + switch (ldsym->def) + { + case LDPK_WEAKDEF: + flags = BSF_WEAK; + /* FALLTHRU */ + case LDPK_DEF: + flags |= BSF_GLOBAL; + if (ldsym->comdat_key) + { + char *name = concat (".gnu.linkonce.t.", ldsym->comdat_key, + (const char *) NULL); + section = bfd_get_section_by_name (abfd, name); + if (section != NULL) + free (name); + else + { + flagword sflags; + + sflags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY + | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE + | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD); + section = bfd_make_section_anyway_with_flags (abfd, name, sflags); + if (section == NULL) + return LDPS_ERR; + } + } + else + 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; + /* For ELF targets, set alignment of common symbol to 1. */ + if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) + { + ((elf_symbol_type *) asym)->internal_elf_sym.st_shndx = SHN_COMMON; + ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1; + } + 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); + unsigned char visibility; + + if (!elfsym) + einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name); + switch (ldsym->visibility) + { + default: + einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"), + ldsym->visibility); + case LDPV_DEFAULT: + visibility = STV_DEFAULT; + break; + case LDPV_PROTECTED: + visibility = STV_PROTECTED; + break; + case LDPV_INTERNAL: + visibility = STV_INTERNAL; + break; + case LDPV_HIDDEN: + visibility = STV_HIDDEN; + break; + } + elfsym->internal_elf_sym.st_other + = (visibility | (elfsym->internal_elf_sym.st_other + & ~ELF_ST_VISIBILITY (-1))); + } + + 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; + + 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 ATTRIBUTE_UNUSED, + struct ld_plugin_input_file *file ATTRIBUTE_UNUSED) +{ + ASSERT (called_plugin); + return LDPS_ERR; +} + +/* Release the input file. */ +static enum ld_plugin_status +release_input_file (const void *handle ATTRIBUTE_UNUSED) +{ + ASSERT (called_plugin); + return LDPS_ERR; +} + +/* Return TRUE if a defined symbol might be reachable from outside the + universe of claimed objects. */ +static inline bfd_boolean +is_visible_from_outside (struct ld_plugin_symbol *lsym, + struct bfd_link_hash_entry *blhe) +{ + struct bfd_sym_chain *sym; + + if (link_info.relocatable) + return TRUE; + if (link_info.export_dynamic || !link_info.executable) + { + /* Check if symbol is hidden by version script. */ + if (bfd_hide_sym_by_version (link_info.version_info, + blhe->root.string)) + return FALSE; + /* Only ELF symbols really have visibility. */ + if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) + { + struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe; + int vis = ELF_ST_VISIBILITY (el->other); + return vis == STV_DEFAULT || vis == STV_PROTECTED; + } + /* On non-ELF targets, we can safely make inferences by considering + what visibility the plugin would have liked to apply when it first + sent us the symbol. During ELF symbol processing, visibility only + ever becomes more restrictive, not less, when symbols are merged, + so this is a conservative estimate; it may give false positives, + declaring something visible from outside when it in fact would + not have been, but this will only lead to missed optimisation + opportunities during LTRANS at worst; it will not give false + negatives, which can lead to the disastrous conclusion that the + related symbol is IRONLY. (See GCC PR46319 for an example.) */ + return (lsym->visibility == LDPV_DEFAULT + || lsym->visibility == LDPV_PROTECTED); + } + + for (sym = &entry_symbol; sym != NULL; sym = sym->next) + if (sym->name + && strcmp (sym->name, blhe->root.string) == 0) + return TRUE; + + return FALSE; +} + +/* 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, + int def_ironly_exp) +{ + const bfd *abfd = handle; + int n; + + ASSERT (called_plugin); + for (n = 0; n < nsyms; n++) + { + struct bfd_link_hash_entry *blhe; + asection *owner_sec; + int res; + + if (syms[n].def != LDPK_UNDEF) + blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name, + FALSE, FALSE, TRUE); + else + blhe = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info, + syms[n].name, FALSE, FALSE, TRUE); + if (!blhe) + { + res = LDPR_UNKNOWN; + goto report_symbol; + } + + /* Determine resolution from blhe type and symbol's original type. */ + if (blhe->type == bfd_link_hash_undefined + || blhe->type == bfd_link_hash_undefweak) + { + res = LDPR_UNDEF; + goto report_symbol; + } + 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)\n", + called_plugin->name, blhe->type); + } + + /* Find out which section owns the symbol. Since it's not undef, + it must have an owner; if it's not a common symbol, both defs + and weakdefs keep it in the same place. */ + owner_sec = (blhe->type == bfd_link_hash_common + ? blhe->u.c.p->section + : blhe->u.def.section); + + + /* 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) + { + if (owner_sec->owner == link_info.output_bfd) + res = LDPR_RESOLVED_EXEC; + else if (owner_sec->owner == abfd) + res = LDPR_PREVAILING_DEF_IRONLY; + else if (is_ir_dummy_bfd (owner_sec->owner)) + res = LDPR_RESOLVED_IR; + else if (owner_sec->owner != NULL + && (owner_sec->owner->flags & DYNAMIC) != 0) + res = LDPR_RESOLVED_DYN; + else + res = LDPR_RESOLVED_EXEC; + } + + /* 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. */ + else if (owner_sec->owner == link_info.output_bfd) + res = LDPR_PREEMPTED_REG; + else if (owner_sec->owner == abfd) + res = LDPR_PREVAILING_DEF_IRONLY; + + /* Was originally def, weakdef, or common, but has been pre-empted. */ + else if (is_ir_dummy_bfd (owner_sec->owner)) + res = LDPR_PREEMPTED_IR; + else + res = LDPR_PREEMPTED_REG; + + if (res == LDPR_PREVAILING_DEF_IRONLY) + { + /* We need to know if the sym is referenced from non-IR files. Or + even potentially-referenced, perhaps in a future final link if + this is a partial one, perhaps dynamically at load-time if the + symbol is externally visible. */ + if (blhe->non_ir_ref) + res = LDPR_PREVAILING_DEF; + else if (is_visible_from_outside (&syms[n], blhe)) + res = def_ironly_exp; + } + + report_symbol: + syms[n].resolution = res; + if (report_plugin_symbols) + einfo (_("%P: %B: symbol `%s' " + "definition: %d, visibility: %d, resolution: %d\n"), + abfd, syms[n].name, + syms[n].def, syms[n].visibility, res); + } + return LDPS_OK; +} + +static enum ld_plugin_status +get_symbols_v1 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) +{ + return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF); +} + +static enum ld_plugin_status +get_symbols_v2 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) +{ + return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF_IRONLY_EXP); +} + +/* 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 (xstrdup (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 (xstrdup (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 (xstrdup (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); + putchar ('\n'); + break; + case LDPL_WARNING: + vfinfo (stdout, format, args, TRUE); + putchar ('\n'); + break; + case LDPL_FATAL: + case LDPL_ERROR: + default: + { + char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%P%F: " : "%P%X: ", + format, "\n", (const char *) NULL)); + fflush (stdout); + vfinfo (stderr, newfmt, args, TRUE); + fflush (stderr); + } + break; + } + + va_end (args); + return LDPS_OK; +} + +/* Helper to size leading part of tv array and set it up. */ +static void +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; + + 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.executable + ? (link_info.pie ? LDPO_PIE : LDPO_EXEC) + : LDPO_DYN)); + 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_v1; + break; + case LDPT_GET_SYMBOLS_V2: + TVU(get_symbols) = get_symbols_v2; + 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 + } +} + +/* 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; +} + +/* Return true if any plugins are active this run. Only valid + after options have been processed. */ +bfd_boolean +plugin_active_plugins_p (void) +{ + return plugins_list != NULL; +} + +/* Load up and initialise all plugins after argument parsing. */ +void +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; + + /* 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; + + onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "onload"); + if (!onloadfn) + onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "_onload"); + if (!onloadfn) + einfo (_("%P%F: %s: error loading plugin: %s\n"), + curplug->name, dlerror ()); + set_tv_plugin_args (curplug, &my_tv[tv_header_size]); + called_plugin = curplug; + rv = (*onloadfn) (my_tv); + called_plugin = NULL; + if (rv != LDPS_OK) + einfo (_("%P%F: %s: plugin error: %d\n"), curplug->name, rv); + 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. */ + orig_notice_all = link_info.notice_all; + orig_callbacks = link_info.callbacks; + plugin_callbacks = *orig_callbacks; + plugin_callbacks.notice = &plugin_notice; + link_info.notice_all = TRUE; + link_info.lto_plugin_active = TRUE; + link_info.callbacks = &plugin_callbacks; +} + +/* Call 'claim file' hook for all plugins. */ +static 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; +} + +void +plugin_maybe_claim (struct ld_plugin_input_file *file, + lang_input_statement_type *entry) +{ + int claimed = 0; + + /* We create a dummy BFD, initially empty, to house whatever symbols + the plugin may want to add. */ + file->handle = plugin_get_ir_dummy_bfd (entry->the_bfd->filename, + entry->the_bfd); + if (plugin_call_claim_file (file, &claimed)) + einfo (_("%P%F: %s: plugin reported error claiming file\n"), + plugin_error_plugin ()); + /* fd belongs to us, not the plugin; but we don't need it. */ + close (file->fd); + if (claimed) + { + /* Discard the real file's BFD and substitute the dummy one. */ + + /* BFD archive handling caches elements so we can't call + bfd_close for archives. */ + if (entry->the_bfd->my_archive == NULL) + bfd_close (entry->the_bfd); + entry->the_bfd = file->handle; + entry->flags.claimed = TRUE; + bfd_make_readable (entry->the_bfd); + } + else + { + /* If plugin didn't claim the file, we don't need the dummy bfd. + Can't avoid speculatively creating it, alas. */ + bfd_close_all_done (file->handle); + entry->flags.claimed = FALSE; + } +} + +/* 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; + + 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 at exit. */ +void +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) + info_msg (_("%P: %s: error in plugin cleanup: %d (ignored)\n"), + curplug->name, rv); + dlclose (curplug->dlhandle); + } + curplug = curplug->next; + } +} + +/* 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. Mark those + referenced from a non-IR file with non_ir_ref. We have to + notice_all symbols, because we won't necessarily know until later + which ones will be contributed by IR files. */ +static bfd_boolean +plugin_notice (struct bfd_link_info *info, + struct bfd_link_hash_entry *h, + struct bfd_link_hash_entry *inh, + bfd *abfd, + asection *section, + bfd_vma value, + flagword flags) +{ + struct bfd_link_hash_entry *orig_h = h; + + if (h != NULL) + { + bfd *sym_bfd; + + if (h->type == bfd_link_hash_warning) + h = h->u.i.link; + + /* Nothing to do here if this def/ref is from an IR dummy BFD. */ + if (is_ir_dummy_bfd (abfd)) + ; + + /* Making an indirect symbol counts as a reference unless this + is a brand new symbol. */ + else if (bfd_is_ind_section (section) + || (flags & BSF_INDIRECT) != 0) + { + /* ??? Some of this is questionable. See comments in + _bfd_generic_link_add_one_symbol for case IND. */ + if (h->type != bfd_link_hash_new) + { + h->non_ir_ref = TRUE; + inh->non_ir_ref = TRUE; + } + else if (inh->type == bfd_link_hash_new) + inh->non_ir_ref = TRUE; + } + + /* Nothing to do here for warning symbols. */ + else if ((flags & BSF_WARNING) != 0) + ; + + /* Nothing to do here for constructor symbols. */ + else if ((flags & BSF_CONSTRUCTOR) != 0) + ; + + /* If this is a ref, set non_ir_ref. */ + else if (bfd_is_und_section (section)) + { + /* Replace the undefined dummy bfd with the real one. */ + if ((h->type == bfd_link_hash_undefined + || h->type == bfd_link_hash_undefweak) + && (h->u.undef.abfd == NULL + || (h->u.undef.abfd->flags & BFD_PLUGIN) != 0)) + h->u.undef.abfd = abfd; + h->non_ir_ref = TRUE; + } + + /* Otherwise, it must be a new def. Ensure any symbol defined + in an IR dummy BFD takes on a new value from a real BFD. + Weak symbols are not normally overridden by a new weak + definition, and strong symbols will normally cause multiple + definition errors. Avoid this by making the symbol appear + to be undefined. */ + else if (((h->type == bfd_link_hash_defweak + || h->type == bfd_link_hash_defined) + && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) + || (h->type == bfd_link_hash_common + && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) + { + h->type = bfd_link_hash_undefweak; + h->u.undef.abfd = sym_bfd; + } + } + + /* Continue with cref/nocrossref/trace-sym processing. */ + if (orig_h == NULL + || orig_notice_all + || (info->notice_hash != NULL + && bfd_hash_lookup (info->notice_hash, orig_h->root.string, + FALSE, FALSE) != NULL)) + return (*orig_callbacks->notice) (info, orig_h, inh, + abfd, section, value, flags); + return TRUE; +} |