On 3/11/20 1:51 PM, Richard Biener wrote:
Splitting an existing field isn't hackish IMHO. I guess even
explicitely changing it
to one short and two char fields would be OK.
Good, I'm doing that in the updated version of that patch.
H.J. is right now working on the corresponding binutils counterpart.
Thoughts?
Martin
>From 8a2e73edb53f26a1b6a543e2e2027b2661a48f94 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Fri, 6 Mar 2020 18:09:35 +0100
Subject: [PATCH] API extension for binutils (type of symbols).
---
gcc/lto-streamer-out.c | 12 +++++
include/lto-symtab.h | 12 +++++
include/plugin-api.h | 30 ++++++++++++-
lto-plugin/lto-plugin.c | 99 +++++++++++++++++++++++++++++++++++++----
4 files changed, 142 insertions(+), 11 deletions(-)
diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c
index cea5e71cffb..b212be35b3d 100644
--- a/gcc/lto-streamer-out.c
+++ b/gcc/lto-streamer-out.c
@@ -45,6 +45,7 @@ along with GCC; see the file COPYING3. If not see
#include "print-tree.h"
#include "tree-dfa.h"
#include "file-prefix-map.h" /* remap_debug_filename() */
+#include "output.h"
static void lto_write_tree (struct output_block*, tree, bool);
@@ -2773,6 +2774,17 @@ write_symbol (struct streamer_tree_cache_d *cache,
lto_write_data (&c, 1);
c = (unsigned char) visibility;
lto_write_data (&c, 1);
+ c = ((unsigned char) TREE_CODE (t) == VAR_DECL
+ ? GCCST_VARIABLE : GCCST_FUNCTION);
+ lto_write_data (&c, 1);
+ unsigned char section_flags = 0;
+ if (TREE_CODE (t) == VAR_DECL)
+ {
+ section *s = get_variable_section (t, false);
+ if (s->common.flags & SECTION_BSS)
+ section_flags |= GCCSSS_BSS;
+ }
+ lto_write_data (§ion_flags, 1);
lto_write_data (&size, 8);
lto_write_data (&slot_num, 4);
}
diff --git a/include/lto-symtab.h b/include/lto-symtab.h
index 0ce0de10121..47f0ff27df8 100644
--- a/include/lto-symtab.h
+++ b/include/lto-symtab.h
@@ -38,4 +38,16 @@ enum gcc_plugin_symbol_visibility
GCCPV_HIDDEN
};
+enum gcc_plugin_symbol_type
+{
+ GCCST_UNKNOWN,
+ GCCST_FUNCTION,
+ GCCST_VARIABLE,
+};
+
+enum gcc_plugin_symbol_section_flags
+{
+ GCCSSS_BSS = 1
+};
+
#endif /* GCC_LTO_SYMTAB_H */
diff --git a/include/plugin-api.h b/include/plugin-api.h
index 09e1202df07..804684449cf 100644
--- a/include/plugin-api.h
+++ b/include/plugin-api.h
@@ -87,7 +87,17 @@ struct ld_plugin_symbol
{
char *name;
char *version;
- int def;
+#ifdef __BIG_ENDIAN__
+ char unused;
+ char section_flags;
+ char symbol_type;
+ char def;
+#else
+ char def;
+ char symbol_type;
+ char section_flags;
+ char unused;
+#endif
int visibility;
uint64_t size;
char *comdat_key;
@@ -123,6 +133,20 @@ enum ld_plugin_symbol_visibility
LDPV_HIDDEN
};
+/* The type of the symbol. */
+
+enum ld_plugin_symbol_type
+{
+ LDST_UNKNOWN,
+ LDST_FUNCTION,
+ LDST_VARIABLE,
+};
+
+enum ld_plugin_symbol_section_flags
+{
+ LDSSS_BSS = 1
+};
+
/* How a symbol is resolved. */
enum ld_plugin_symbol_resolution
@@ -431,7 +455,9 @@ enum ld_plugin_tag
LDPT_GET_INPUT_SECTION_ALIGNMENT = 29,
LDPT_GET_INPUT_SECTION_SIZE = 30,
LDPT_REGISTER_NEW_INPUT_HOOK = 31,
- LDPT_GET_WRAP_SYMBOLS = 32
+ LDPT_GET_WRAP_SYMBOLS = 32,
+ LDPT_ADD_SYMBOLS_V2 = 33,
+ LDPT_GET_SYMBOLS_V4 = 34,
};
/* The plugin transfer vector. */
diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
index c307fc871bf..bce9f183049 100644
--- a/lto-plugin/lto-plugin.c
+++ b/lto-plugin/lto-plugin.c
@@ -90,6 +90,8 @@ along with this program; see the file COPYING3. If not see
#define LTO_SECTION_PREFIX ".gnu.lto_.symtab"
#define LTO_SECTION_PREFIX_LEN (sizeof (LTO_SECTION_PREFIX) - 1)
+#define LTO_LTO_PREFIX ".gnu.lto_.lto"
+#define LTO_LTO_PREFIX_LEN (sizeof (LTO_LTO_PREFIX) - 1)
#define OFFLOAD_SECTION ".gnu.offload_lto_.opts"
#define OFFLOAD_SECTION_LEN (sizeof (OFFLOAD_SECTION) - 1)
@@ -154,12 +156,12 @@ enum symbol_style
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_get_symbols get_symbols, get_symbols_v2, get_symbols_v4;
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;
+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;
@@ -221,6 +223,20 @@ check_1 (int gate, enum ld_plugin_level level, const char *text)
}
}
+/* Structure that represents LTO ELF section with information
+ about the format. */
+
+struct lto_section
+ {
+ int16_t major_version;
+ int16_t minor_version;
+ unsigned char slim_object: 1;
+ unsigned char compression: 4;
+ int32_t reserved0: 27;
+};
+
+struct lto_section lto_header;
+
/* 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. */
@@ -252,6 +268,13 @@ parse_table_entry (char *p, struct ld_plugin_symbol *entry,
LDPV_HIDDEN
};
+ enum ld_plugin_symbol_type symbol_types[] =
+ {
+ LDST_UNKNOWN,
+ LDST_FUNCTION,
+ LDST_VARIABLE,
+ };
+
switch (sym_style)
{
case ss_win32:
@@ -296,6 +319,19 @@ parse_table_entry (char *p, struct ld_plugin_symbol *entry,
entry->visibility = translate_visibility[t];
p++;
+ /* Symbol type was added in GCC 10.1 (LTO version 9.0). */
+ if (lto_header.major_version >= 9)
+ {
+ t = *p;
+ check (t <= 3, LDPL_FATAL, "invalid symbol type found");
+ entry->symbol_type = symbol_types[t];
+ p++;
+ entry->section_flags = *p;
+ p++;
+ }
+
+ entry->unused = 0;
+
memcpy (&entry->size, p, sizeof (uint64_t));
p += 8;
@@ -431,7 +467,7 @@ finish_conflict_resolution (struct plugin_symtab *symtab,
for (i = 0; i < symtab->nsyms; i++)
{
- int resolution = LDPR_UNKNOWN;
+ char resolution = LDPR_UNKNOWN;
if (symtab->aux[i].next_conflict == -1)
continue;
@@ -473,6 +509,19 @@ free_symtab (struct plugin_symtab *symtab)
symtab->aux = NULL;
}
+/* Clear new flags symbol_type and section_flags
+ from symbol table entries. */
+
+static void
+clear_new_symtab_flags (struct plugin_symtab *out)
+{
+ for (unsigned i = 0; i < out->nsyms; i++)
+ {
+ out->syms[i].symbol_type = 0;
+ out->syms[i].section_flags = 0;
+ }
+}
+
/* Writes the relocations to disk. */
static void
@@ -495,10 +544,16 @@ write_resolution (void)
/* 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);
+ if (get_symbols_v4)
+ get_symbols_v4 (info->handle, symtab->nsyms, syms);
else
- get_symbols (info->handle, symtab->nsyms, syms);
+ {
+ clear_new_symtab_flags (symtab);
+ 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);
@@ -951,7 +1006,20 @@ 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;
+ char *secdatastart = NULL, *secdata;
+
+ if (strncmp (name, LTO_LTO_PREFIX, LTO_LTO_PREFIX_LEN) == 0)
+ {
+ if (offset != lseek (obj->file->fd, offset, SEEK_SET))
+ goto err;
+
+ ssize_t got = read (obj->file->fd, <o_header,
+ sizeof (struct lto_section));
+ if (got != sizeof (struct lto_section))
+ goto err;
+
+ return 1;
+ }
if (strncmp (name, LTO_SECTION_PREFIX, LTO_SECTION_PREFIX_LEN) != 0)
return 1;
@@ -1080,8 +1148,15 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
if (obj.found > 0)
{
- status = add_symbols (file->handle, lto_file.symtab.nsyms,
- lto_file.symtab.syms);
+ if (add_symbols_v2)
+ status = add_symbols_v2 (file->handle, lto_file.symtab.nsyms,
+ lto_file.symtab.syms);
+ else
+ {
+ clear_new_symtab_flags (<o_file.symtab);
+ 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++;
@@ -1242,12 +1317,18 @@ onload (struct ld_plugin_tv *tv)
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_V4:
+ get_symbols_v4 = p->tv_u.tv_get_symbols;
+ break;
case LDPT_GET_SYMBOLS_V2:
get_symbols_v2 = p->tv_u.tv_get_symbols;
break;
--
2.25.1
