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Re: [lto][patch] Add initial gold plugin
- From: "Rafael Espindola" <espindola at google dot com>
- To: "Diego Novillo" <dnovillo at google dot com>
- Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>, "Cary Coutant" <ccoutant at google dot com>
- Date: Mon, 1 Sep 2008 15:34:52 +0100
- Subject: Re: [lto][patch] Add initial gold plugin
- References: <38a0d8450808270339p3054cacbq9265a0168e1afd78@mail.gmail.com> <48B59D48.9060105@google.com> <38a0d8450809010734h6f3fc082gbb1cc567436ce33@mail.gmail.com>
> An updated version is attached. Could you please take another look?
Now it is ...
Cheers,
--
Rafael Avila de Espindola
Google | Gordon House | Barrow Street | Dublin 4 | Ireland
Registered in Dublin, Ireland | Registration Number: 368047
diff --git a/lto-plugin/Makefile.am b/lto-plugin/Makefile.am
index db159bd..acc0565 100644
--- a/lto-plugin/Makefile.am
+++ b/lto-plugin/Makefile.am
@@ -1,4 +1,13 @@
AM_CPPFLAGS = -I$(top_srcdir)/../include
+
+AM_CFLAGS = -Wall -Werror
+
bin_PROGRAMS = ltosymtab
+
ltosymtab_SOURCES = lto-symtab.c
-ltosymtab_LDADD = -lelf
+ltosymtab_LDADD = -ldl
+
+lib_LTLIBRARIES = liblto_plugin.la
+
+liblto_plugin_la_SOURCES = lto-plugin.c
+liblto_plugin_la_LIBADD = -lelf
diff --git a/lto-plugin/acinclude.m4 b/lto-plugin/acinclude.m4
index 9302f26..655ba7a 100644
--- a/lto-plugin/acinclude.m4
+++ b/lto-plugin/acinclude.m4
@@ -1,3 +1,6 @@
-m4_include(../config/acx.m4)
-m4_include(../config/no-executables.m4)
m4_include([../config/libelf.m4])
+m4_include([../ltsugar.m4])
+m4_include([../ltoptions.m4])
+m4_include([../ltversion.m4])
+
+sinclude(../libtool.m4)
diff --git a/lto-plugin/configure.ac b/lto-plugin/configure.ac
index e967a22..c2c9ea5 100644
--- a/lto-plugin/configure.ac
+++ b/lto-plugin/configure.ac
@@ -4,5 +4,6 @@ GCC_TOPLEV_SUBDIRS
AM_INIT_AUTOMAKE([foreign])
AC_PROG_CC
AC_CHECK_GELF
+AM_PROG_LIBTOOL
AC_CONFIG_FILES(Makefile)
AC_OUTPUT
diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
new file mode 100644
index 0000000..bd4b2f4
--- /dev/null
+++ b/lto-plugin/lto-plugin.c
@@ -0,0 +1,247 @@
+/* LTO plugin for gold.
+ Copyright (C) 2008 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 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. */
+
+/* The plugin has only one external function: onload. Gold passes it an array of
+ function that the plugin uses to communicate back to gold.
+
+ With the functions provided by gold, the plugin can be notified when
+ gold first analyzes a file and pass a symbol table back to gold. 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.
+*/
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef HAVE_GELF_H
+# include <gelf.h>
+#else
+# if defined(HAVE_LIBELF_GELF_H)
+# include <libelf/gelf.h>
+# else
+# error "gelf.h not available"
+# endif
+#endif
+
+#include "plugin-api.h"
+
+static ld_plugin_register_claim_file register_claim_file;
+static ld_plugin_add_symbols add_symbols;
+
+/* 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, uint32_t *slot)
+{
+ 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
+ };
+
+ entry->name = p;
+ while (*p)
+ p++;
+ p++;
+
+ entry->version = NULL;
+
+ entry->comdat_key = p;
+ while (*p)
+ p++;
+ p++;
+
+ if (strcmp (entry->comdat_key, "") == 0)
+ entry->comdat_key = NULL;
+
+ t = *p;
+ assert (t <= 4);
+ entry->def = translate_kind[t];
+ p++;
+
+ t = *p;
+ assert (t <= 3);
+ entry->visibility = translate_visibility[t];
+ p++;
+
+ entry->size = *(uint64_t *) p;
+ p += 8;
+
+ *slot = *(uint32_t *) p;
+ p += 4;
+
+ entry->resolution = LDPR_UNKNOWN;
+
+ return p;
+}
+
+/* Returns the string table of file ELF. */
+
+static const char *
+get_string_table (Elf *elf)
+{
+ GElf_Ehdr header;
+ GElf_Ehdr *t = gelf_getehdr (elf, &header);
+ assert (t == &header);
+ Elf_Scn *section = elf_getscn (elf, header.e_shstrndx);
+ assert (section);
+ Elf_Data *data = 0;
+ data = elf_getdata (section, data);
+ assert (data);
+ assert (data->d_buf);
+ return (const char *) data->d_buf;
+}
+
+
+/* Return the section in ELF that is named NAME. */
+
+static Elf_Scn *
+get_section (Elf *elf, const char *name)
+{
+ const char *string_table = get_string_table (elf);
+ Elf_Scn *section = 0;
+ while ((section = elf_nextscn(elf, section)) != 0)
+ {
+ GElf_Shdr shdr;
+ GElf_Shdr *tshdr = gelf_getshdr (section, &shdr);
+ const char *t;
+ assert (tshdr == &shdr);
+ t = string_table + shdr.sh_name;
+ if (strcmp (t, name) == 0)
+ return section;
+ }
+ return NULL;
+}
+
+/* Returns the IL symbol table of file ELF. */
+
+static Elf_Data *
+get_symtab (Elf *elf)
+{
+ Elf_Data *data = 0;
+ Elf_Scn *section = get_section (elf, ".gnu.lto_.symtab");
+ if (!section)
+ return NULL;
+
+ data = elf_getdata (section, data);
+ assert (data);
+ return data;
+}
+
+/* Translate the IL symbol tabel SYMTAB into an array of ld_plugin_symbol
+ and return it. Write the array size in SIZE. */
+
+static struct ld_plugin_symbol *
+translate (Elf_Data *symtab, int *size)
+{
+ char *data = symtab->d_buf;
+ char *end = data + symtab->d_size;
+ struct ld_plugin_symbol *ret = NULL;
+ int n = 0;
+ while (data < end)
+ {
+ uint32_t slot;
+ n++;
+ ret = realloc (ret, n * sizeof (struct ld_plugin_symbol));
+ assert (ret);
+ data = parse_table_entry (data, &ret[n - 1], &slot);
+ }
+ *size = n;
+ return ret;
+}
+
+/* Callback used by gold 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;
+ Elf *elf = elf_begin (file->fd, ELF_C_READ, NULL);
+ int num;
+ Elf_Data *symtab;
+ struct ld_plugin_symbol *syms;
+
+ *claimed = 0;
+
+ if (!elf)
+ return LDPS_OK;
+
+ symtab = get_symtab (elf);
+ if (!symtab)
+ return LDPS_OK;
+
+ syms = translate (symtab, &num);
+
+ status = add_symbols (file->handle, num, syms);
+ assert (status == LDPS_OK);
+
+ *claimed = 1;
+ return LDPS_OK;
+}
+
+/* Called by gold after loading the plugin. TV is the transfer vector. */
+
+void
+onload (struct ld_plugin_tv *tv)
+{
+ struct ld_plugin_tv *p;
+ enum ld_plugin_status status;
+
+ unsigned version = elf_version (EV_CURRENT);
+ assert (version != EV_NONE);
+
+ p = tv;
+ while (p->tv_tag)
+ {
+ switch (p->tv_tag)
+ {
+ case LDPT_REGISTER_CLAIM_FILE_HOOK:
+ register_claim_file = p->tv_u.tv_register_claim_file;
+ break;
+ case LDPT_ADD_SYMBOLS:
+ add_symbols = p->tv_u.tv_add_symbols;
+ break;
+ default:
+ break;
+ }
+ p++;
+ }
+
+ assert (register_claim_file);
+ assert (add_symbols);
+ status = register_claim_file (claim_file_handler);
+ assert (status == LDPS_OK);
+}
diff --git a/lto-plugin/lto-symtab.c b/lto-plugin/lto-symtab.c
index 82253f2..126c563 100644
--- a/lto-plugin/lto-symtab.c
+++ b/lto-plugin/lto-symtab.c
@@ -1,10 +1,10 @@
/* Program to read the IL symbol table.
- Copyright (C) 1999, 2000, 2002, 2003, 2004 Free Software Foundation, Inc.
- Contributed by Vladimir Makarov (vmakarov@cygnus.com).
+ Copyright (C) 2008 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 2 of the License, or
+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,
@@ -18,146 +18,126 @@ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
#include <fcntl.h>
#include <assert.h>
-#ifdef HAVE_GELF_H
-# include <gelf.h>
-#else
-# if defined(HAVE_LIBELF_GELF_H)
-# include <libelf/gelf.h>
-# else
-# error "gelf.h not available"
-# endif
-#endif
+#include <dlfcn.h>
#include <stdio.h>
-#include <string.h>
-#include "lto-symtab.h"
+#include <inttypes.h>
-/* Return the string table of ELF. */
-const char *
-get_string_table (Elf *elf)
+
+#include "plugin-api.h"
+
+ld_plugin_claim_file_handler claim_file_handler;
+void *current_file_handle;
+
+/* Register HANDLER as the callback for claiming a file. */
+
+enum ld_plugin_status
+register_claim_file(ld_plugin_claim_file_handler handler)
{
- GElf_Ehdr header;
- GElf_Ehdr *t = gelf_getehdr (elf, &header);
- assert (t == &header);
- Elf_Scn *section = elf_getscn (elf, header.e_shstrndx);
- assert (section);
- Elf_Data *data = 0;
- data = elf_getdata (section, data);
- assert (data);
- assert (data->d_buf);
- return (const char *) data->d_buf;
+ claim_file_handler = handler;
+ return LDPS_OK;
}
-/* Return the section in ELF that is named NAME. */
+/* For a file identified by HANDLE, add NSYMS symbols from SYMS. */
-Elf_Scn *
-get_section (Elf *elf, const char *name)
+static enum ld_plugin_status
+add_symbols (const void *handle, int nsyms,
+ const struct ld_plugin_symbol *syms)
{
- const char *string_table = get_string_table (elf);
- Elf_Scn *section = 0;
- while ((section = elf_nextscn(elf, section)) != 0)
+ const char *kind_str[] = {"DEF", "WEAKDEF", "UNDEF",
+ "WEAKUNDEF", "COMMON"};
+ const char *visibility_str[] = {"DEFAULT", "PROTECTED",
+ "INTERNAL", "HIDDEN"};
+ const char *resolution_str[] = {"UNKNOWN", "UNDEF",
+ "PREVAILING_DEF",
+ "PREVAILING_DEF_IRONLY",
+ "PREEMPTED_REG",
+ "PREEMPTED_IR",
+ "RESOLVED_IR",
+ "RESOLVED_EXEC",
+ "RESOLVED_DYN"};
+
+ int i;
+ assert (handle == current_file_handle);
+
+ for (i = 0; i < nsyms; i++)
{
- GElf_Shdr shdr;
- GElf_Shdr *tshdr = gelf_getshdr (section, &shdr);
- const char *t;
- assert (tshdr == &shdr);
- t = string_table + shdr.sh_name;
- if (strcmp (t, name) == 0)
- return section;
+ printf("name: %s; ", syms[i].name);
+ if (syms[i].version)
+ printf("version: %s;", syms[i].version);
+ else
+ printf("not versioned; ");
+ printf("kind: %s; ", kind_str[syms[i].def]);
+ printf("visibility: %s; ", visibility_str[syms[i].visibility]);
+ printf("size: %" PRId64 "; ", syms[i].size);
+ if (syms[i].comdat_key)
+ printf("comdat_key: %s; ", syms[i].comdat_key);
+ else
+ printf("no comdat_key; ");
+ printf ("resolution: %s\n", resolution_str[syms[i].resolution]);
}
- return NULL;
+ return LDPS_OK;
}
-/* Return the IL symbol table of ELF. */
+struct ld_plugin_tv tv[] = {
+ {LDPT_REGISTER_CLAIM_FILE_HOOK,
+ {.tv_register_claim_file = register_claim_file}
+ },
+ {LDPT_ADD_SYMBOLS,
+ {.tv_add_symbols = add_symbols}
+ },
-Elf_Data *
-get_symtab (Elf *elf)
-{
- Elf_Scn *section = get_section (elf, ".gnu.lto_.symtab");
- assert (section);
- Elf_Data *data = 0;
- data = elf_getdata (section, data);
- assert (data);
- return data;
-}
-
-struct table_entry
-{
- char *name;
- char *comdat;
- enum gcc_plugin_symbol_kind kind;
- enum gcc_plugin_symbol_visibility visibility;
- uint64_t size;
- uint32_t slot_num;
+ {0, {0}}
};
-/* Parse an entry of the IL symbol table. The data to be parsed is pointed
- by P and the result is written in ENTRY. Returs the address of the next
- entry. */
+/* Load a plugin from a file named NAME. */
-char *parse_table_entry (char *p, struct table_entry *entry)
+static void
+load_plugin (const char *name)
{
- entry->name = p;
- while (*p)
- p++;
- p++;
-
- entry->comdat = p;
- while (*p)
- p++;
- p++;
+ ld_plugin_onload onload;
+ void *lib = dlopen (name, RTLD_LAZY);
+
+ assert (lib != NULL);
+ onload = dlsym (lib, "onload");
+ assert (onload);
+ onload (tv);
+ assert (claim_file_handler);
+}
- entry->kind = *p;
- assert (entry->kind <= 4);
- p++;
+/* Send file named NAME to the plugin. */
- entry->visibility = *p;
- assert (entry->visibility <= 3);
- p++;
+static void
+register_file (const char *name)
+{
+ int claimed;
+ struct ld_plugin_input_file file;
+ int fd = open (name, O_RDONLY);
+ assert (fd >= 0);
- entry->size = *(uint64_t *) p;
- p += 8;
+ file.name = (char *) name;
+ file.fd = fd;
+ file.offset = 0; /* Used only in archives. */
+ file.filesize = 0; /* Used only in archives. */
- entry->slot_num = *(uint32_t *) p;
- p += 4;
+ /* Just to check that the plugin keeps it. */
+ file.handle = &file;
+ current_file_handle = file.handle;
- return p;
+ claim_file_handler (&file, &claimed);
}
-/* Print the symbol table SYMTAB to stdout. */
-
-void printTable (Elf_Data *symtab)
+int
+main(int argc, char *argv[])
{
- char *data = symtab->d_buf;
- char *end = data + symtab->d_size;
- while (data < end)
- {
- struct table_entry entry;
- const char *kind_str[] = {"GCCPK_DEF", "GCCPK_WEAKDEF", "GCCPK_UNDEF",
- "GCCPK_WEAKUNDEF", "GCCPK_COMMON"};
- const char *visibility_str[] = {"GCCPV_DEFAULT", "GCCPV_PROTECTED",
- "GCCPV_INTERNAL", "GCCPV_HIDDEN"};
- data = parse_table_entry (data, &entry);
-
- printf("%s %s %s %s %lld %d\n", entry.name, entry.comdat,
- kind_str[entry.kind], visibility_str[entry.visibility],
- entry.size, entry.slot_num);
- }
-}
+ const char *plugin;
+ const char *obj;
+ assert (argc == 3);
+ plugin = argv[1];
+ obj = argv[2];
+
+ load_plugin (plugin);
+ register_file (obj);
-int main (int argc, char *argv[])
-{
- unsigned version = elf_version(EV_CURRENT);
- assert (version != EV_NONE);
- assert (argc == 2);
- int fd = open (argv[1], O_RDONLY);
- assert (fd >= 0);
- Elf *elf = elf_begin(fd, ELF_C_READ, NULL);
- assert (elf);
-
- Elf_Data *symtab = get_symtab (elf);
- printTable (symtab);
-
- elf_end(elf);
return 0;
}
diff --git a/lto-plugin/plugin-api.h b/lto-plugin/plugin-api.h
new file mode 100644
index 0000000..7f96bbd
--- /dev/null
+++ b/lto-plugin/plugin-api.h
@@ -0,0 +1,237 @@
+/* plugin-api.h -- External plugin API for gold. */
+
+/* Copyright 2008 Free Software Foundation, Inc.
+ Written by Cary Coutant <ccoutant@google.com>.
+
+ This file is part of gold.
+
+ 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. */
+
+/* This file defines the interface for writing a linker plugin, which is
+ described at < http://gcc.gnu.org/wiki/whopr/driver >. */
+
+#ifndef GOLD_PLUGIN_API_H
+#define GOLD_PLUGIN_API_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/* Status code returned by most API routines. */
+
+enum ld_plugin_status {
+ LDPS_OK = 0,
+ LDPS_ERR,
+ /* Additional Error codes TBD. */
+};
+
+/* The version of the API specification. */
+
+enum ld_plugin_api_version
+{
+ LD_PLUGIN_API_VERSION = 1,
+};
+
+/* The type of output file being generated by the linker. */
+
+enum ld_plugin_output_file_type
+{
+ LDPO_REL,
+ LDPO_EXEC,
+ LDPO_DYN,
+};
+
+/* An input file managed by the plugin library. */
+
+struct ld_plugin_input_file
+{
+ const char *name;
+ int fd;
+ off_t offset;
+ off_t filesize;
+ void *handle;
+};
+
+/* A symbol belonging to an input file managed by the plugin library. */
+
+struct ld_plugin_symbol
+{
+ char *name;
+ char *version;
+ int def;
+ int visibility;
+ uint64_t size;
+ char *comdat_key;
+ int resolution;
+};
+
+/* Whether the symbol is a definition, reference, or common, weak or not. */
+
+enum ld_plugin_symbol_kind
+{
+ LDPK_DEF,
+ LDPK_WEAKDEF,
+ LDPK_UNDEF,
+ LDPK_WEAKUNDEF,
+ LDPK_COMMON,
+};
+
+/* The visibility of the symbol. */
+
+enum ld_plugin_symbol_visibility
+{
+ LDPV_DEFAULT,
+ LDPV_PROTECTED,
+ LDPV_INTERNAL,
+ LDPV_HIDDEN,
+};
+
+/* How a symbol is resolved. */
+
+enum ld_plugin_symbol_resolution
+{
+ LDPR_UNKNOWN = 0,
+ LDPR_UNDEF,
+ LDPR_PREVAILING_DEF,
+ LDPR_PREVAILING_DEF_IRONLY,
+ LDPR_PREEMPTED_REG,
+ LDPR_PREEMPTED_IR,
+ LDPR_RESOLVED_IR,
+ LDPR_RESOLVED_EXEC,
+ LDPR_RESOLVED_DYN,
+};
+
+/* The plugin library's "claim file" handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_claim_file_handler) (
+ const struct ld_plugin_input_file *file, int *claimed);
+
+/* The plugin library's "all symbols read" handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_all_symbols_read_handler) ();
+
+/* The plugin library's cleanup handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_cleanup_handler) ();
+
+/* The linker's interface for registering the "claim file" handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_register_claim_file) (ld_plugin_claim_file_handler handler);
+
+/* The linker's interface for registering the "all symbols read" handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_register_all_symbols_read) (
+ ld_plugin_all_symbols_read_handler handler);
+
+/* The linker's interface for registering the cleanup handler. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_register_cleanup) (ld_plugin_cleanup_handler handler);
+
+/* The linker's interface for adding symbols from a claimed input file. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_add_symbols) (const void *handle, int nsyms,
+ const struct ld_plugin_symbol *syms);
+
+/* The linker's interface for retrieving symbol resolution information. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_get_symbols) (void *handle, int nsyms,
+ struct ld_plugin_symbol *syms);
+
+/* The linker's interface for adding a compiled input file. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_add_input_file) (char *pathname);
+
+/* The linker's interface for issuing a warning or error message. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_message) (int level, char *format, ...);
+
+enum ld_plugin_level
+{
+ LDPL_INFO,
+ LDPL_WARNING,
+ LDPL_ERROR,
+ LDPL_FATAL,
+};
+
+/* Values for the tv_tag field of the transfer vector. */
+
+enum ld_plugin_tag
+{
+ LDPT_NULL = 0,
+ LDPT_API_VERSION,
+ LDPT_GOLD_VERSION,
+ LDPT_LINKER_OUTPUT,
+ LDPT_OPTION,
+ LDPT_REGISTER_CLAIM_FILE_HOOK,
+ LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK,
+ LDPT_REGISTER_CLEANUP_HOOK,
+ LDPT_ADD_SYMBOLS,
+ LDPT_GET_SYMBOLS,
+ LDPT_ADD_INPUT_FILE,
+ LDPT_MESSAGE,
+};
+
+/* The plugin transfer vector. */
+
+struct ld_plugin_tv
+{
+ enum ld_plugin_tag tv_tag;
+ union
+ {
+ int tv_val;
+ const char *tv_string;
+ ld_plugin_register_claim_file tv_register_claim_file;
+ ld_plugin_register_all_symbols_read tv_register_all_symbols_read;
+ ld_plugin_register_cleanup tv_register_cleanup;
+ ld_plugin_add_symbols tv_add_symbols;
+ ld_plugin_get_symbols tv_get_symbols;
+ ld_plugin_add_input_file tv_add_input_file;
+ ld_plugin_message tv_message;
+ } tv_u;
+};
+
+/* The plugin library's "onload" entry point. */
+
+typedef
+enum ld_plugin_status
+(*ld_plugin_onload) (struct ld_plugin_tv *tv);
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif /* !defined(GOLD_PLUGIN_API_H) */