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- /* LTO plugin for linkers like gold, GNU ld or mold.
- Copyright (C) 2009-2022 Free Software Foundation, Inc.
- Contributed by Rafael Avila de Espindola (espindola@google.com).
- 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, 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; see the file COPYING3. If not see
- <http://www.gnu.org/licenses/>. */
- /* The plugin has only one external function: onload. A linker passes it an array of
- function that the plugin uses to communicate back to the linker.
- With the functions provided by the linker, the plugin can be notified when
- the linker first analyzes a file and pass a symbol table back to the linker. The plugin
- is also notified when all symbols have been read and it is time to generate
- machine code for the necessary symbols.
- More information at http://gcc.gnu.org/wiki/whopr/driver.
- This plugin should be passed the lto-wrapper options and will forward them.
- It also has options at his own:
- -debug: Print the command line used to run lto-wrapper.
- -nop: Instead of running lto-wrapper, pass the original to the plugin. This
- only works if the input files are hybrid.
- -linker-output-known: Do not determine linker output
- -linker-output-auto-nolto-rel: Switch from rel to nolto-rel mode without
- warning. This is used on systems like VxWorks (kernel) where the link is
- always partial and repeated incremental linking is generally not used.
- -sym-style={none,win32,underscore|uscore}
- -pass-through */
- #ifdef HAVE_CONFIG_H
- #include "config.h"
- #endif
- #if HAVE_STDINT_H
- #include <stdint.h>
- #endif
- #include <stdbool.h>
- #include <assert.h>
- #include <errno.h>
- #include <string.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <inttypes.h>
- #include <sys/stat.h>
- #include <unistd.h>
- #include <fcntl.h>
- #include <sys/types.h>
- #ifdef HAVE_SYS_WAIT_H
- #include <sys/wait.h>
- #endif
- #ifndef WIFEXITED
- #define WIFEXITED(S) (((S) & 0xff) == 0)
- #endif
- #ifndef WEXITSTATUS
- #define WEXITSTATUS(S) (((S) & 0xff00) >> 8)
- #endif
- #include <libiberty.h>
- #include <hashtab.h>
- #include "../gcc/lto/common.h"
- #include "simple-object.h"
- #include "plugin-api.h"
- /* We need to use I64 instead of ll width-specifier on native Windows.
- The reason for this is that older MS-runtimes don't support the ll. */
- #ifdef __MINGW32__
- #define PRI_LL "I64"
- #else
- #define PRI_LL "ll"
- #endif
- /* Handle opening elf files on hosts, such as Windows, that may use
- text file handling that will break binary access. */
- #ifndef O_BINARY
- # define O_BINARY 0
- #endif
- /* Segment name for LTO sections. This is only used for Mach-O.
- FIXME: This needs to be kept in sync with darwin.c. */
- #define LTO_SEGMENT_NAME "__GNU_LTO"
- /* Return true if STR string starts with PREFIX. */
- static inline bool
- startswith (const char *str, const char *prefix)
- {
- return strncmp (str, prefix, strlen (prefix)) == 0;
- }
- /* The part of the symbol table the plugin has to keep track of. Note that we
- must keep SYMS until all_symbols_read is called to give the linker time to
- copy the symbol information.
- The id must be 64bit to minimze collisions. */
- struct sym_aux
- {
- uint32_t slot;
- unsigned long long id;
- unsigned next_conflict;
- };
- struct plugin_symtab
- {
- int nsyms;
- int last_sym;
- struct sym_aux *aux;
- struct ld_plugin_symbol *syms;
- unsigned long long id;
- };
- /* Encapsulates object file data during symbol scan. */
- struct plugin_objfile
- {
- int found;
- int offload;
- simple_object_read *objfile;
- struct plugin_symtab *out;
- const struct ld_plugin_input_file *file;
- };
- /* All that we have to remember about a file. */
- struct plugin_file_info
- {
- char *name;
- void *handle;
- struct plugin_symtab symtab;
- struct plugin_symtab conflicts;
- };
- /* List item with name of the file with offloading. */
- struct plugin_offload_file
- {
- char *name;
- struct plugin_offload_file *next;
- };
- /* Until ASM_OUTPUT_LABELREF can be hookized and decoupled from
- stdio file streams, we do simple label translation here. */
- enum symbol_style
- {
- ss_none, /* No underscore prefix. */
- ss_win32, /* Underscore prefix any symbol not beginning with '@'. */
- ss_uscore, /* Underscore prefix all symbols. */
- };
- static char *arguments_file_name;
- static ld_plugin_register_claim_file register_claim_file;
- static ld_plugin_register_all_symbols_read register_all_symbols_read;
- static ld_plugin_get_symbols get_symbols, get_symbols_v2;
- static ld_plugin_register_cleanup register_cleanup;
- static ld_plugin_add_input_file add_input_file;
- static ld_plugin_add_input_library add_input_library;
- static ld_plugin_message message;
- static ld_plugin_add_symbols add_symbols, add_symbols_v2;
- static struct plugin_file_info *claimed_files = NULL;
- static unsigned int num_claimed_files = 0;
- static unsigned int non_claimed_files = 0;
- /* List of files with offloading. */
- static struct plugin_offload_file *offload_files;
- /* Last file in the list. */
- static struct plugin_offload_file *offload_files_last;
- /* Last non-archive file in the list. */
- static struct plugin_offload_file *offload_files_last_obj;
- /* Last LTO file in the list. */
- static struct plugin_offload_file *offload_files_last_lto;
- /* Total number of files with offloading. */
- static unsigned num_offload_files;
- static char **output_files = NULL;
- static unsigned int num_output_files = 0;
- static char **lto_wrapper_argv;
- static int lto_wrapper_num_args;
- static char **pass_through_items = NULL;
- static unsigned int num_pass_through_items;
- static char *ltrans_objects = NULL;
- static bool debug;
- static bool save_temps;
- static bool verbose;
- static char nop;
- static char *resolution_file = NULL;
- static enum ld_plugin_output_file_type linker_output;
- static bool linker_output_set;
- static bool linker_output_known;
- static bool linker_output_auto_nolto_rel;
- static const char *link_output_name = NULL;
- /* This indicates link_output_name already contains the dot of the
- suffix, so we can skip it in extensions. */
- static int skip_in_suffix = 0;
- /* The version of gold being used, or -1 if not gold. The number is
- MAJOR * 100 + MINOR. */
- static int gold_version = -1;
- /* Not used by default, but can be overridden at runtime
- by using -plugin-opt=-sym-style={none,win32,underscore|uscore}
- (in fact, only first letter of style arg is checked.) */
- static enum symbol_style sym_style = ss_none;
- static void
- check_1 (int gate, enum ld_plugin_level level, const char *text)
- {
- if (gate)
- return;
- if (message)
- message (level, text);
- else
- {
- /* If there is no nicer way to inform the user, fallback to stderr. */
- fprintf (stderr, "%s\n", text);
- if (level == LDPL_FATAL)
- abort ();
- }
- }
- /* This little wrapper allows check to be called with a non-integer
- first argument, such as a pointer that must be non-NULL. We can't
- use c99 bool type to coerce it into range, so we explicitly test. */
- #define check(GATE, LEVEL, TEXT) check_1 (((GATE) != 0), (LEVEL), (TEXT))
- /* Parse an entry of the IL symbol table. The data to be parsed is pointed
- by P and the result is written in ENTRY. The slot number is stored in SLOT.
- Returns the address of the next entry. */
- static char *
- parse_table_entry (char *p, struct ld_plugin_symbol *entry,
- struct sym_aux *aux)
- {
- unsigned char t;
- enum ld_plugin_symbol_kind translate_kind[] =
- {
- LDPK_DEF,
- LDPK_WEAKDEF,
- LDPK_UNDEF,
- LDPK_WEAKUNDEF,
- LDPK_COMMON
- };
- enum ld_plugin_symbol_visibility translate_visibility[] =
- {
- LDPV_DEFAULT,
- LDPV_PROTECTED,
- LDPV_INTERNAL,
- LDPV_HIDDEN
- };
- switch (sym_style)
- {
- case ss_win32:
- if (p[0] == '@')
- {
- /* cf. Duff's device. */
- case ss_none:
- entry->name = xstrdup (p);
- break;
- }
- /* FALL-THROUGH. */
- case ss_uscore:
- entry->name = concat ("_", p, NULL);
- break;
- default:
- check (0, LDPL_FATAL, "invalid symbol style requested");
- break;
- }
- while (*p)
- p++;
- p++;
- entry->version = NULL;
- entry->comdat_key = p;
- while (*p)
- p++;
- p++;
- if (strlen (entry->comdat_key) == 0)
- entry->comdat_key = NULL;
- else
- entry->comdat_key = xstrdup (entry->comdat_key);
- entry->unused = entry->section_kind = entry->symbol_type = 0;
- t = *p;
- check (t <= 4, LDPL_FATAL, "invalid symbol kind found");
- entry->def = translate_kind[t];
- p++;
- t = *p;
- check (t <= 3, LDPL_FATAL, "invalid symbol visibility found");
- entry->visibility = translate_visibility[t];
- p++;
- memcpy (&entry->size, p, sizeof (uint64_t));
- p += 8;
- memcpy (&aux->slot, p, sizeof (uint32_t));
- p += 4;
- entry->resolution = LDPR_UNKNOWN;
- aux->next_conflict = -1;
- return p;
- }
- /* Parse an entry of the IL symbol table. The data to be parsed is pointed
- by P and the result is written in ENTRY. The slot number is stored in SLOT.
- Returns the address of the next entry. */
- static char *
- parse_table_entry_extension (char *p, struct ld_plugin_symbol *entry)
- {
- unsigned char t;
- enum ld_plugin_symbol_type symbol_types[] =
- {
- LDST_UNKNOWN,
- LDST_FUNCTION,
- LDST_VARIABLE,
- };
- t = *p;
- check (t <= 2, LDPL_FATAL, "invalid symbol type found");
- entry->symbol_type = symbol_types[t];
- p++;
- entry->section_kind = *p;
- p++;
- return p;
- }
- /* Translate the IL symbol table located between DATA and END. Append the
- slots and symbols to OUT. */
- static void
- translate (char *data, char *end, struct plugin_symtab *out)
- {
- struct sym_aux *aux;
- struct ld_plugin_symbol *syms = NULL;
- int n, len;
- /* This overestimates the output buffer sizes, but at least
- the algorithm is O(1) now. */
- len = (end - data)/8 + out->nsyms + 1;
- syms = xrealloc (out->syms, len * sizeof (struct ld_plugin_symbol));
- aux = xrealloc (out->aux, len * sizeof (struct sym_aux));
-
- for (n = out->nsyms; data < end; n++)
- {
- aux[n].id = out->id;
- data = parse_table_entry (data, &syms[n], &aux[n]);
- }
- assert(n < len);
- out->nsyms = n;
- out->syms = syms;
- out->aux = aux;
- }
- static void
- parse_symtab_extension (char *data, char *end, struct plugin_symtab *out)
- {
- unsigned long i;
- unsigned char version;
- if (data >= end)
- /* FIXME: Issue an error ? */
- return;
- version = *data;
- data++;
- if (version != 1)
- return;
- /* Version 1 contains the following data per entry:
- - symbol_type
- - section_kind
- . */
- unsigned long nsyms = (end - data) / 2;
- for (i = 0; i < nsyms; i++)
- data = parse_table_entry_extension (data, out->syms + i + out->last_sym);
- out->last_sym += nsyms;
- }
- /* Free all memory that is no longer needed after writing the symbol
- resolution. */
- static void
- free_1 (struct plugin_file_info *files, unsigned num_files)
- {
- unsigned int i;
- for (i = 0; i < num_files; i++)
- {
- struct plugin_file_info *info = &files[i];
- struct plugin_symtab *symtab = &info->symtab;
- unsigned int j;
- for (j = 0; j < symtab->nsyms; j++)
- {
- struct ld_plugin_symbol *s = &symtab->syms[j];
- free (s->name);
- free (s->comdat_key);
- }
- free (symtab->syms);
- symtab->syms = NULL;
- }
- }
- /* Free all remaining memory. */
- static void
- free_2 (void)
- {
- unsigned int i;
- for (i = 0; i < num_claimed_files; i++)
- {
- struct plugin_file_info *info = &claimed_files[i];
- struct plugin_symtab *symtab = &info->symtab;
- free (symtab->aux);
- free (info->name);
- }
- for (i = 0; i < num_output_files; i++)
- free (output_files[i]);
- free (output_files);
- free (claimed_files);
- claimed_files = NULL;
- num_claimed_files = 0;
- while (offload_files)
- {
- struct plugin_offload_file *ofld = offload_files;
- offload_files = offload_files->next;
- free (ofld);
- }
- num_offload_files = 0;
- free (arguments_file_name);
- arguments_file_name = NULL;
- }
- /* Dump SYMTAB to resolution file F. */
- static void
- dump_symtab (FILE *f, struct plugin_symtab *symtab)
- {
- unsigned j;
- for (j = 0; j < symtab->nsyms; j++)
- {
- uint32_t slot = symtab->aux[j].slot;
- unsigned int resolution = symtab->syms[j].resolution;
-
- assert (resolution != LDPR_UNKNOWN);
- fprintf (f, "%u %" PRI_LL "x %s %s\n",
- (unsigned int) slot, symtab->aux[j].id,
- lto_resolution_str[resolution],
- symtab->syms[j].name);
- }
- }
- /* Finish the conflicts' resolution information after the linker resolved
- the original symbols */
- static void
- finish_conflict_resolution (struct plugin_symtab *symtab,
- struct plugin_symtab *conflicts)
- {
- int i, j;
- if (conflicts->nsyms == 0)
- return;
- for (i = 0; i < symtab->nsyms; i++)
- {
- char resolution = LDPR_UNKNOWN;
- if (symtab->aux[i].next_conflict == -1)
- continue;
- switch (symtab->syms[i].def)
- {
- case LDPK_DEF:
- case LDPK_COMMON: /* ??? */
- resolution = LDPR_RESOLVED_IR;
- break;
- case LDPK_WEAKDEF:
- resolution = LDPR_PREEMPTED_IR;
- break;
- case LDPK_UNDEF:
- case LDPK_WEAKUNDEF:
- resolution = symtab->syms[i].resolution;
- break;
- default:
- assert (0);
- }
- assert (resolution != LDPR_UNKNOWN);
- for (j = symtab->aux[i].next_conflict;
- j != -1;
- j = conflicts->aux[j].next_conflict)
- conflicts->syms[j].resolution = resolution;
- }
- }
- /* Free symbol table SYMTAB. */
- static void
- free_symtab (struct plugin_symtab *symtab)
- {
- free (symtab->syms);
- symtab->syms = NULL;
- free (symtab->aux);
- symtab->aux = NULL;
- }
- /* Writes the relocations to disk. */
- static void
- write_resolution (void)
- {
- unsigned int i;
- FILE *f;
- check (resolution_file, LDPL_FATAL, "resolution file not specified");
- f = fopen (resolution_file, "w");
- check (f, LDPL_FATAL, "could not open file");
- fprintf (f, "%d\n", num_claimed_files);
- for (i = 0; i < num_claimed_files; i++)
- {
- struct plugin_file_info *info = &claimed_files[i];
- struct plugin_symtab *symtab = &info->symtab;
- struct ld_plugin_symbol *syms = symtab->syms;
- /* Version 2 of API supports IRONLY_EXP resolution that is
- accepted by GCC-4.7 and newer. */
- if (get_symbols_v2)
- get_symbols_v2 (info->handle, symtab->nsyms, syms);
- else
- get_symbols (info->handle, symtab->nsyms, syms);
- finish_conflict_resolution (symtab, &info->conflicts);
- fprintf (f, "%s %d\n", info->name, symtab->nsyms + info->conflicts.nsyms);
- dump_symtab (f, symtab);
- if (info->conflicts.nsyms)
- {
- dump_symtab (f, &info->conflicts);
- free_symtab (&info->conflicts);
- }
- }
- fclose (f);
- }
- /* Pass files generated by the lto-wrapper to the linker. FD is lto-wrapper's
- stdout. */
- static void
- add_output_files (FILE *f)
- {
- for (;;)
- {
- const unsigned piece = 32;
- char *buf, *s = xmalloc (piece);
- size_t len;
- buf = s;
- cont:
- if (!fgets (buf, piece, f))
- {
- free (s);
- break;
- }
- len = strlen (s);
- if (s[len - 1] != '\n')
- {
- s = xrealloc (s, len + piece);
- buf = s + len;
- goto cont;
- }
- s[len - 1] = '\0';
- num_output_files++;
- output_files
- = xrealloc (output_files, num_output_files * sizeof (char *));
- output_files[num_output_files - 1] = s;
- add_input_file (output_files[num_output_files - 1]);
- }
- }
- /* Execute the lto-wrapper. ARGV[0] is the binary. The rest of ARGV is the
- argument list. */
- static void
- exec_lto_wrapper (char *argv[])
- {
- int t, i;
- int status;
- char *at_args;
- FILE *args;
- FILE *wrapper_output;
- char *new_argv[3];
- struct pex_obj *pex;
- const char *errmsg;
- /* Write argv to a file to avoid a command line that is too long
- Save the file locally on save-temps. */
- const char *suffix = ".lto_wrapper_args";
- suffix += skip_in_suffix;
- if (save_temps && link_output_name)
- arguments_file_name = concat (link_output_name, suffix, NULL);
- else
- arguments_file_name = make_temp_file (".lto_wrapper_args");
- check (arguments_file_name, LDPL_FATAL,
- "Failed to generate a temorary file name");
- args = fopen (arguments_file_name, "w");
- check (args, LDPL_FATAL, "could not open arguments file");
- t = writeargv (&argv[1], args);
- check (t == 0, LDPL_FATAL, "could not write arguments");
- t = fclose (args);
- check (t == 0, LDPL_FATAL, "could not close arguments file");
- at_args = concat ("@", arguments_file_name, NULL);
- check (at_args, LDPL_FATAL, "could not allocate");
- for (i = 1; argv[i]; i++)
- {
- char *a = argv[i];
- /* Check the input argument list for a verbose marker too. */
- if (a[0] == '-' && a[1] == 'v' && a[2] == '\0')
- {
- verbose = true;
- break;
- }
- }
- if (verbose)
- {
- for (i = 0; argv[i]; i++)
- fprintf (stderr, "%s ", argv[i]);
- fprintf (stderr, "\n");
- }
- new_argv[0] = argv[0];
- new_argv[1] = at_args;
- new_argv[2] = NULL;
- if (debug)
- {
- for (i = 0; new_argv[i]; i++)
- fprintf (stderr, "%s ", new_argv[i]);
- fprintf (stderr, "\n");
- }
- pex = pex_init (PEX_USE_PIPES, "lto-wrapper", NULL);
- check (pex != NULL, LDPL_FATAL, "could not pex_init lto-wrapper");
- errmsg = pex_run (pex, 0, new_argv[0], new_argv, NULL, NULL, &t);
- check (errmsg == NULL, LDPL_FATAL, "could not run lto-wrapper");
- check (t == 0, LDPL_FATAL, "could not run lto-wrapper");
- wrapper_output = pex_read_output (pex, 0);
- check (wrapper_output, LDPL_FATAL, "could not read lto-wrapper output");
- add_output_files (wrapper_output);
- t = pex_get_status (pex, 1, &status);
- check (t == 1, LDPL_FATAL, "could not get lto-wrapper exit status");
- check (WIFEXITED (status) && WEXITSTATUS (status) == 0, LDPL_FATAL,
- "lto-wrapper failed");
- pex_free (pex);
- free (at_args);
- }
- /* Pass the original files back to the linker. */
- static void
- use_original_files (void)
- {
- unsigned i;
- for (i = 0; i < num_claimed_files; i++)
- {
- struct plugin_file_info *info = &claimed_files[i];
- add_input_file (info->name);
- }
- }
- /* Called by the linker once all symbols have been read. */
- static enum ld_plugin_status
- all_symbols_read_handler (void)
- {
- const unsigned num_lto_args
- = num_claimed_files + lto_wrapper_num_args + 2
- + !linker_output_known + !linker_output_auto_nolto_rel;
- unsigned i;
- char **lto_argv;
- const char *linker_output_str = NULL;
- const char **lto_arg_ptr;
- if (num_claimed_files + num_offload_files == 0)
- return LDPS_OK;
- if (nop)
- {
- use_original_files ();
- return LDPS_OK;
- }
- if (ltrans_objects)
- {
- FILE *objs = fopen (ltrans_objects, "r");
- add_output_files (objs);
- fclose (objs);
- return LDPS_OK;
- }
- lto_argv = (char **) xcalloc (sizeof (char *), num_lto_args);
- lto_arg_ptr = (const char **) lto_argv;
- assert (lto_wrapper_argv);
- write_resolution ();
- free_1 (claimed_files, num_claimed_files);
- for (i = 0; i < lto_wrapper_num_args; i++)
- *lto_arg_ptr++ = lto_wrapper_argv[i];
- if (!linker_output_known)
- {
- assert (linker_output_set);
- switch (linker_output)
- {
- case LDPO_REL:
- if (non_claimed_files)
- {
- if (!linker_output_auto_nolto_rel)
- message (LDPL_WARNING, "incremental linking of LTO and non-LTO"
- " objects; using -flinker-output=nolto-rel which will"
- " bypass whole program optimization");
- linker_output_str = "-flinker-output=nolto-rel";
- }
- else
- linker_output_str = "-flinker-output=rel";
- break;
- case LDPO_DYN:
- linker_output_str = "-flinker-output=dyn";
- break;
- case LDPO_PIE:
- linker_output_str = "-flinker-output=pie";
- break;
- case LDPO_EXEC:
- linker_output_str = "-flinker-output=exec";
- break;
- default:
- message (LDPL_FATAL, "unsupported linker output %i", linker_output);
- break;
- }
- *lto_arg_ptr++ = xstrdup (linker_output_str);
- }
- if (num_offload_files > 0)
- {
- FILE *f;
- char *arg;
- char *offload_objects_file_name;
- struct plugin_offload_file *ofld;
- const char *suffix = ".ofldlist";
- if (save_temps && link_output_name)
- {
- suffix += skip_in_suffix;
- offload_objects_file_name = concat (link_output_name, suffix, NULL);
- }
- else
- offload_objects_file_name = make_temp_file (suffix);
- check (offload_objects_file_name, LDPL_FATAL,
- "Failed to generate a temporary file name");
- f = fopen (offload_objects_file_name, "w");
- check (f, LDPL_FATAL, "could not open file with offload objects");
- fprintf (f, "%u\n", num_offload_files);
- /* Skip the dummy item at the start of the list. */
- ofld = offload_files->next;
- while (ofld)
- {
- fprintf (f, "%s\n", ofld->name);
- ofld = ofld->next;
- }
- fclose (f);
- arg = concat ("-foffload-objects=", offload_objects_file_name, NULL);
- check (arg, LDPL_FATAL, "could not allocate");
- *lto_arg_ptr++ = arg;
- }
- for (i = 0; i < num_claimed_files; i++)
- {
- struct plugin_file_info *info = &claimed_files[i];
- *lto_arg_ptr++ = info->name;
- }
- *lto_arg_ptr++ = NULL;
- exec_lto_wrapper (lto_argv);
- free (lto_argv);
- /* --pass-through is not needed when using gold 1.11 or later. */
- if (pass_through_items && gold_version < 111)
- {
- unsigned int i;
- for (i = 0; i < num_pass_through_items; i++)
- {
- if (startswith (pass_through_items[i], "-l"))
- add_input_library (pass_through_items[i] + 2);
- else
- add_input_file (pass_through_items[i]);
- free (pass_through_items[i]);
- pass_through_items[i] = NULL;
- }
- free (pass_through_items);
- pass_through_items = NULL;
- }
- return LDPS_OK;
- }
- /* Helper, as used in collect2. */
- static int
- file_exists (const char *name)
- {
- return access (name, R_OK) == 0;
- }
- /* Unlink FILE unless we have save-temps set.
- Note that we're saving files if verbose output is set. */
- static void
- maybe_unlink (const char *file)
- {
- if (save_temps && file_exists (file))
- {
- if (verbose)
- fprintf (stderr, "[Leaving %s]\n", file);
- return;
- }
- unlink_if_ordinary (file);
- }
- /* Remove temporary files at the end of the link. */
- static enum ld_plugin_status
- cleanup_handler (void)
- {
- unsigned int i;
- if (debug)
- return LDPS_OK;
- if (arguments_file_name)
- maybe_unlink (arguments_file_name);
- for (i = 0; i < num_output_files; i++)
- maybe_unlink (output_files[i]);
- free_2 ();
- return LDPS_OK;
- }
- #define SWAP(type, a, b) \
- do { type tmp_; tmp_ = (a); (a) = (b); (b) = tmp_; } while(0)
- /* Compare two hash table entries */
- static int eq_sym (const void *a, const void *b)
- {
- const struct ld_plugin_symbol *as = (const struct ld_plugin_symbol *)a;
- const struct ld_plugin_symbol *bs = (const struct ld_plugin_symbol *)b;
- return !strcmp (as->name, bs->name);
- }
- /* Hash a symbol */
- static hashval_t hash_sym (const void *a)
- {
- const struct ld_plugin_symbol *as = (const struct ld_plugin_symbol *)a;
- return htab_hash_string (as->name);
- }
- /* Determine how strong a symbol is */
- static int symbol_strength (struct ld_plugin_symbol *s)
- {
- switch (s->def)
- {
- case LDPK_UNDEF:
- case LDPK_WEAKUNDEF:
- return 0;
- case LDPK_WEAKDEF:
- return 1;
- default:
- return 2;
- }
- }
- /* In the ld -r case we can get dups in the LTO symbol tables, where
- the same symbol can have different resolutions (e.g. undefined and defined).
- We have to keep that in the LTO symbol tables, but the dups confuse
- gold and then finally gcc by supplying incorrect resolutions.
- Problem is that the main gold symbol table doesn't know about subids
- and does not distingush the same symbols in different states.
- So we drop duplicates from the linker visible symbol table
- and keep them in a private table. Then later do own symbol
- resolution for the duplicated based on the results for the
- originals.
- Then when writing out the resolution file readd the dropped symbols.
-
- XXX how to handle common? */
- static void
- resolve_conflicts (struct plugin_symtab *t, struct plugin_symtab *conflicts)
- {
- htab_t symtab = htab_create (t->nsyms, hash_sym, eq_sym, NULL);
- int i;
- int out;
- int outlen;
- outlen = t->nsyms;
- conflicts->syms = xmalloc (sizeof (struct ld_plugin_symbol) * outlen);
- conflicts->aux = xmalloc (sizeof (struct sym_aux) * outlen);
- /* Move all duplicate symbols into the auxiliary conflicts table. */
- out = 0;
- for (i = 0; i < t->nsyms; i++)
- {
- struct ld_plugin_symbol *s = &t->syms[i];
- struct sym_aux *aux = &t->aux[i];
- void **slot;
- slot = htab_find_slot (symtab, s, INSERT);
- if (*slot != NULL)
- {
- int cnf;
- struct ld_plugin_symbol *orig = (struct ld_plugin_symbol *)*slot;
- struct sym_aux *orig_aux = &t->aux[orig - t->syms];
- /* Always let the linker resolve the strongest symbol */
- if (symbol_strength (orig) < symbol_strength (s))
- {
- SWAP (struct ld_plugin_symbol, *orig, *s);
- SWAP (uint32_t, orig_aux->slot, aux->slot);
- SWAP (unsigned long long, orig_aux->id, aux->id);
- /* Don't swap conflict chain pointer */
- }
- /* Move current symbol into the conflicts table */
- cnf = conflicts->nsyms++;
- conflicts->syms[cnf] = *s;
- conflicts->aux[cnf] = *aux;
- aux = &conflicts->aux[cnf];
- /* Update conflicts chain of the original symbol */
- aux->next_conflict = orig_aux->next_conflict;
- orig_aux->next_conflict = cnf;
- continue;
- }
- /* Remove previous duplicates in the main table */
- if (out < i)
- {
- t->syms[out] = *s;
- t->aux[out] = *aux;
- }
- /* Put original into the hash table */
- *slot = &t->syms[out];
- out++;
- }
- assert (conflicts->nsyms <= outlen);
- assert (conflicts->nsyms + out == t->nsyms);
-
- t->nsyms = out;
- htab_delete (symtab);
- }
- /* Process one section of an object file. */
- static int
- process_symtab (void *data, const char *name, off_t offset, off_t length)
- {
- struct plugin_objfile *obj = (struct plugin_objfile *)data;
- char *s;
- char *secdatastart, *secdata;
- if (!startswith (name, ".gnu.lto_.symtab"))
- return 1;
- s = strrchr (name, '.');
- if (s)
- sscanf (s, ".%" PRI_LL "x", &obj->out->id);
- secdata = secdatastart = xmalloc (length);
- offset += obj->file->offset;
- if (offset != lseek (obj->file->fd, offset, SEEK_SET))
- goto err;
- do
- {
- ssize_t got = read (obj->file->fd, secdata, length);
- if (got == 0)
- break;
- else if (got > 0)
- {
- secdata += got;
- length -= got;
- }
- else if (errno != EINTR)
- goto err;
- }
- while (length > 0);
- if (length > 0)
- goto err;
- translate (secdatastart, secdata, obj->out);
- obj->found++;
- free (secdatastart);
- return 1;
- err:
- if (message)
- message (LDPL_FATAL, "%s: corrupt object file", obj->file->name);
- /* Force claim_file_handler to abandon this file. */
- obj->found = 0;
- free (secdatastart);
- return 0;
- }
- /* Process one section of an object file. */
- static int
- process_symtab_extension (void *data, const char *name, off_t offset,
- off_t length)
- {
- struct plugin_objfile *obj = (struct plugin_objfile *)data;
- char *s;
- char *secdatastart, *secdata;
- if (!startswith (name, ".gnu.lto_.ext_symtab"))
- return 1;
- s = strrchr (name, '.');
- if (s)
- sscanf (s, ".%" PRI_LL "x", &obj->out->id);
- secdata = secdatastart = xmalloc (length);
- offset += obj->file->offset;
- if (offset != lseek (obj->file->fd, offset, SEEK_SET))
- goto err;
- do
- {
- ssize_t got = read (obj->file->fd, secdata, length);
- if (got == 0)
- break;
- else if (got > 0)
- {
- secdata += got;
- length -= got;
- }
- else if (errno != EINTR)
- goto err;
- }
- while (length > 0);
- if (length > 0)
- goto err;
- parse_symtab_extension (secdatastart, secdata, obj->out);
- obj->found++;
- free (secdatastart);
- return 1;
- err:
- if (message)
- message (LDPL_FATAL, "%s: corrupt object file", obj->file->name);
- /* Force claim_file_handler to abandon this file. */
- obj->found = 0;
- free (secdatastart);
- return 0;
- }
- /* Find an offload section of an object file. */
- static int
- process_offload_section (void *data, const char *name, off_t offset, off_t len)
- {
- if (startswith (name, ".gnu.offload_lto_.opts"))
- {
- struct plugin_objfile *obj = (struct plugin_objfile *) data;
- obj->offload = 1;
- return 0;
- }
- return 1;
- }
- /* Callback used by a linker to check if the plugin will claim FILE. Writes
- the result in CLAIMED. */
- static enum ld_plugin_status
- claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
- {
- enum ld_plugin_status status;
- struct plugin_objfile obj;
- struct plugin_file_info lto_file;
- int err;
- const char *errmsg;
- memset (<o_file, 0, sizeof (struct plugin_file_info));
- if (file->offset != 0)
- {
- /* We pass the offset of the actual file, not the archive header.
- Can't use PRIx64, because that's C99, so we have to print the
- 64-bit hex int as two 32-bit ones. Use xasprintf instead of
- asprintf because asprintf doesn't work as expected on some older
- mingw32 hosts. */
- int lo, hi;
- lo = file->offset & 0xffffffff;
- hi = ((int64_t)file->offset >> 32) & 0xffffffff;
- lto_file.name = hi ? xasprintf ("%s@0x%x%08x", file->name, hi, lo)
- : xasprintf ("%s@0x%x", file->name, lo);
- }
- else
- {
- lto_file.name = xstrdup (file->name);
- }
- lto_file.handle = file->handle;
- *claimed = 0;
- obj.file = file;
- obj.found = 0;
- obj.offload = 0;
- obj.out = <o_file.symtab;
- errmsg = NULL;
- obj.objfile = simple_object_start_read (file->fd, file->offset, LTO_SEGMENT_NAME,
- &errmsg, &err);
- /* No file, but also no error code means unrecognized format; just skip it. */
- if (!obj.objfile && !err)
- goto err;
- if (obj.objfile)
- {
- errmsg = simple_object_find_sections (obj.objfile, process_symtab, &obj,
- &err);
- /* Parsing symtab extension should be done only for add_symbols_v2 and
- later versions. */
- if (!errmsg && add_symbols_v2 != NULL)
- {
- obj.out->last_sym = 0;
- errmsg = simple_object_find_sections (obj.objfile,
- process_symtab_extension,
- &obj, &err);
- }
- }
- if (!obj.objfile || errmsg)
- {
- if (err && message)
- message (LDPL_FATAL, "%s: %s: %s", file->name, errmsg,
- xstrerror (err));
- else if (message)
- message (LDPL_FATAL, "%s: %s", file->name, errmsg);
- goto err;
- }
- if (obj.objfile)
- simple_object_find_sections (obj.objfile, process_offload_section,
- &obj, &err);
- if (obj.found == 0 && obj.offload == 0)
- goto err;
- if (obj.found > 1)
- resolve_conflicts (<o_file.symtab, <o_file.conflicts);
- if (obj.found > 0)
- {
- if (add_symbols_v2)
- status = add_symbols_v2 (file->handle, lto_file.symtab.nsyms,
- lto_file.symtab.syms);
- else
- status = add_symbols (file->handle, lto_file.symtab.nsyms,
- lto_file.symtab.syms);
- check (status == LDPS_OK, LDPL_FATAL, "could not add symbols");
- num_claimed_files++;
- claimed_files =
- xrealloc (claimed_files,
- num_claimed_files * sizeof (struct plugin_file_info));
- claimed_files[num_claimed_files - 1] = lto_file;
- *claimed = 1;
- }
- if (offload_files == NULL)
- {
- /* Add dummy item to the start of the list. */
- offload_files = xmalloc (sizeof (struct plugin_offload_file));
- offload_files->name = NULL;
- offload_files->next = NULL;
- offload_files_last = offload_files;
- }
- /* If this is an LTO file without offload, and it is the first LTO file, save
- the pointer to the last offload file in the list. Further offload LTO
- files will be inserted after it, if any. */
- if (*claimed && obj.offload == 0 && offload_files_last_lto == NULL)
- offload_files_last_lto = offload_files_last;
- if (obj.offload == 1)
- {
- /* Add file to the list. The order must be exactly the same as the final
- order after recompilation and linking, otherwise host and target tables
- with addresses wouldn't match. If a static library contains both LTO
- and non-LTO objects, ld and gold link them in a different order. */
- struct plugin_offload_file *ofld
- = xmalloc (sizeof (struct plugin_offload_file));
- ofld->name = lto_file.name;
- ofld->next = NULL;
- if (*claimed && offload_files_last_lto == NULL && file->offset != 0
- && gold_version == -1)
- {
- /* ld only: insert first LTO file from the archive after the last real
- object file immediately preceding the archive, or at the begin of
- the list if there was no real objects before archives. */
- if (offload_files_last_obj != NULL)
- {
- ofld->next = offload_files_last_obj->next;
- offload_files_last_obj->next = ofld;
- }
- else
- {
- ofld->next = offload_files->next;
- offload_files->next = ofld;
- }
- }
- else if (*claimed && offload_files_last_lto != NULL)
- {
- /* Insert LTO file after the last LTO file in the list. */
- ofld->next = offload_files_last_lto->next;
- offload_files_last_lto->next = ofld;
- }
- else
- /* Add non-LTO file or first non-archive LTO file to the end of the
- list. */
- offload_files_last->next = ofld;
- if (ofld->next == NULL)
- offload_files_last = ofld;
- if (file->offset == 0)
- offload_files_last_obj = ofld;
- if (*claimed)
- offload_files_last_lto = ofld;
- num_offload_files++;
- }
- goto cleanup;
- err:
- non_claimed_files++;
- free (lto_file.name);
- cleanup:
- if (obj.objfile)
- simple_object_release_read (obj.objfile);
- return LDPS_OK;
- }
- /* Parse the plugin options. */
- static void
- process_option (const char *option)
- {
- if (strcmp (option, "-linker-output-known") == 0)
- linker_output_known = true;
- /* Also accept "notlo" for backwards compatibility. */
- else if ((strcmp (option, "-linker-output-auto-nolto-rel") == 0)
- || (strcmp (option, "-linker-output-auto-notlo-rel") == 0))
- linker_output_auto_nolto_rel = true;
- else if (strcmp (option, "-debug") == 0)
- debug = true;
- else if ((strcmp (option, "-v") == 0)
- || (strcmp (option, "--verbose") == 0))
- verbose = true;
- else if (strcmp (option, "-save-temps") == 0)
- save_temps = true;
- else if (strcmp (option, "-nop") == 0)
- nop = 1;
- else if (startswith (option, "-pass-through="))
- {
- num_pass_through_items++;
- pass_through_items = xrealloc (pass_through_items,
- num_pass_through_items * sizeof (char *));
- pass_through_items[num_pass_through_items - 1] =
- xstrdup (option + strlen ("-pass-through="));
- }
- else if (startswith (option, "-sym-style="))
- {
- switch (option[sizeof ("-sym-style=") - 1])
- {
- case 'w':
- sym_style = ss_win32;
- break;
- case 'u':
- sym_style = ss_uscore;
- break;
- default:
- sym_style = ss_none;
- break;
- }
- }
- else if (startswith (option, "-ltrans-objects="))
- ltrans_objects = xstrdup (option + strlen ("-ltrans-objects="));
- else
- {
- int size;
- char *opt = xstrdup (option);
- lto_wrapper_num_args += 1;
- size = lto_wrapper_num_args * sizeof (char *);
- lto_wrapper_argv = (char **) xrealloc (lto_wrapper_argv, size);
- lto_wrapper_argv[lto_wrapper_num_args - 1] = opt;
- if (startswith (option, "-fresolution="))
- resolution_file = opt + sizeof ("-fresolution=") - 1;
- }
- save_temps = save_temps || debug;
- verbose = verbose || debug;
- }
- /* Called by a linker after loading the plugin. TV is the transfer vector. */
- enum ld_plugin_status
- onload (struct ld_plugin_tv *tv)
- {
- struct ld_plugin_tv *p;
- enum ld_plugin_status status;
- p = tv;
- while (p->tv_tag)
- {
- switch (p->tv_tag)
- {
- case LDPT_MESSAGE:
- message = p->tv_u.tv_message;
- break;
- case LDPT_REGISTER_CLAIM_FILE_HOOK:
- register_claim_file = p->tv_u.tv_register_claim_file;
- break;
- case LDPT_ADD_SYMBOLS_V2:
- add_symbols_v2 = p->tv_u.tv_add_symbols;
- break;
- case LDPT_ADD_SYMBOLS:
- add_symbols = p->tv_u.tv_add_symbols;
- break;
- case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
- register_all_symbols_read = p->tv_u.tv_register_all_symbols_read;
- break;
- case LDPT_GET_SYMBOLS_V2:
- get_symbols_v2 = p->tv_u.tv_get_symbols;
- break;
- case LDPT_GET_SYMBOLS:
- get_symbols = p->tv_u.tv_get_symbols;
- break;
- case LDPT_REGISTER_CLEANUP_HOOK:
- register_cleanup = p->tv_u.tv_register_cleanup;
- break;
- case LDPT_ADD_INPUT_FILE:
- add_input_file = p->tv_u.tv_add_input_file;
- break;
- case LDPT_ADD_INPUT_LIBRARY:
- add_input_library = p->tv_u.tv_add_input_library;
- break;
- case LDPT_OPTION:
- process_option (p->tv_u.tv_string);
- break;
- case LDPT_GOLD_VERSION:
- gold_version = p->tv_u.tv_val;
- break;
- case LDPT_LINKER_OUTPUT:
- linker_output = (enum ld_plugin_output_file_type) p->tv_u.tv_val;
- linker_output_set = true;
- break;
- case LDPT_OUTPUT_NAME:
- /* We only use this to make user-friendly temp file names. */
- link_output_name = p->tv_u.tv_string;
- break;
- default:
- break;
- }
- p++;
- }
- check (register_claim_file, LDPL_FATAL, "register_claim_file not found");
- check (add_symbols, LDPL_FATAL, "add_symbols not found");
- status = register_claim_file (claim_file_handler);
- check (status == LDPS_OK, LDPL_FATAL,
- "could not register the claim_file callback");
- if (register_cleanup)
- {
- status = register_cleanup (cleanup_handler);
- check (status == LDPS_OK, LDPL_FATAL,
- "could not register the cleanup callback");
- }
- if (register_all_symbols_read)
- {
- check (get_symbols, LDPL_FATAL, "get_symbols not found");
- status = register_all_symbols_read (all_symbols_read_handler);
- check (status == LDPS_OK, LDPL_FATAL,
- "could not register the all_symbols_read callback");
- }
- char *collect_gcc_options = getenv ("COLLECT_GCC_OPTIONS");
- if (collect_gcc_options)
- {
- /* Support -fno-use-linker-plugin by failing to load the plugin
- for the case where it is auto-loaded by BFD. */
- if (strstr (collect_gcc_options, "'-fno-use-linker-plugin'"))
- return LDPS_ERR;
- if (strstr (collect_gcc_options, "'-save-temps'"))
- save_temps = true;
- if (strstr (collect_gcc_options, "'-v'")
- || strstr (collect_gcc_options, "'--verbose'"))
- verbose = true;
- const char *p;
- if ((p = strstr (collect_gcc_options, "'-dumpdir'")))
- {
- p += sizeof ("'-dumpdir'");
- while (*p == ' ')
- p++;
- const char *start = p;
- int ticks = 0, escapes = 0;
- /* Count ticks (') and escaped (\.) characters. Stop at the
- end of the options or at a blank after an even number of
- ticks (not counting escaped ones. */
- for (p = start; *p; p++)
- {
- if (*p == '\'')
- {
- ticks++;
- continue;
- }
- else if ((ticks % 2) != 0)
- {
- if (*p == ' ')
- break;
- if (*p == '\\')
- {
- if (*++p)
- escapes++;
- else
- p--;
- }
- }
- }
- /* Now allocate a new link_output_name and decode dumpdir
- into it. The loop uses the same logic, except it counts
- ticks and escapes backwards (so ticks is adjusted if we
- find an odd number of them), and it copies characters
- that are escaped or not otherwise skipped. */
- int len = p - start - ticks - escapes + 1;
- char *q = xmalloc (len);
- link_output_name = q;
- int oddticks = (ticks % 2);
- ticks += oddticks;
- for (p = start; *p; p++)
- {
- if (*p == '\'')
- {
- ticks--;
- continue;
- }
- else if ((ticks % 2) != 0)
- {
- if (*p == ' ')
- break;
- if (*p == '\\')
- {
- if (*++p)
- escapes--;
- else
- p--;
- }
- }
- *q++ = *p;
- }
- *q = '\0';
- assert (escapes == 0);
- assert (ticks == oddticks);
- assert (q - link_output_name == len - 1);
- skip_in_suffix = 1;
- }
- }
- return LDPS_OK;
- }
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