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/* LTO routines to use object files.
Copyright (C) 2010-2021 Free Software Foundation, Inc.
Written by Ian Lance Taylor, Google.
This file is part of GCC.
GCC 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.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "diagnostic-core.h"
#include "lto.h"
#include "lto-section-names.h"
#include "simple-object.h"
/* An LTO file wrapped around an simple_object. */
struct lto_simple_object
{
/* The base information. */
lto_file base;
/* The system file descriptor. */
int fd;
/* The simple_object if we are reading the file. */
simple_object_read *sobj_r;
/* The simple_object if we are writing the file. */
simple_object_write *sobj_w;
/* The currently active section. */
simple_object_write_section *section;
};
/* Saved simple_object attributes. FIXME: Once set, this is never
cleared. */
static simple_object_attributes *saved_attributes;
/* Initialize FILE, an LTO file object for FILENAME. */
static void
lto_file_init (lto_file *file, const char *filename, off_t offset)
{
file->filename = filename;
file->offset = offset;
}
/* Open the file FILENAME. It WRITABLE is true, the file is opened
for write and, if necessary, created. Otherwise, the file is
opened for reading. Returns the opened file. */
lto_file *
lto_obj_file_open (const char *filename, bool writable)
{
const char *offset_p;
long loffset;
int consumed;
char *fname;
off_t offset;
struct lto_simple_object *lo;
const char *errmsg;
int err;
offset_p = strrchr (filename, '@');
if (offset_p != NULL
&& offset_p != filename
&& sscanf (offset_p, "@%li%n", &loffset, &consumed) >= 1
&& strlen (offset_p) == (unsigned int) consumed)
{
fname = XNEWVEC (char, offset_p - filename + 1);
memcpy (fname, filename, offset_p - filename);
fname[offset_p - filename] = '\0';
offset = (off_t) loffset;
}
else
{
fname = xstrdup (filename);
offset = 0;
}
lo = XCNEW (struct lto_simple_object);
lto_file_init ((lto_file *) lo, fname, offset);
lo->fd = open (fname,
(writable
? O_WRONLY | O_CREAT | O_BINARY
: O_RDONLY | O_BINARY),
0666);
if (lo->fd == -1)
{
error ("open %s failed: %s", fname, xstrerror (errno));
goto fail;
}
if (!writable)
{
simple_object_attributes *attrs;
lo->sobj_r = simple_object_start_read (lo->fd, offset, LTO_SEGMENT_NAME,
&errmsg, &err);
if (lo->sobj_r == NULL)
goto fail_errmsg;
attrs = simple_object_fetch_attributes (lo->sobj_r, &errmsg, &err);
if (attrs == NULL)
goto fail_errmsg;
if (saved_attributes == NULL)
saved_attributes = attrs;
else
{
errmsg = simple_object_attributes_merge (saved_attributes, attrs,
&err);
if (errmsg != NULL)
{
free (attrs);
goto fail_errmsg;
}
}
}
else
{
gcc_assert (saved_attributes != NULL);
lo->sobj_w = simple_object_start_write (saved_attributes,
LTO_SEGMENT_NAME,
&errmsg, &err);
if (lo->sobj_w == NULL)
goto fail_errmsg;
}
return &lo->base;
fail_errmsg:
if (err == 0)
error ("%s: %s", fname, errmsg);
else
error ("%s: %s: %s", fname, errmsg, xstrerror (err));
fail:
if (lo->fd != -1)
lto_obj_file_close ((lto_file *) lo);
free (lo);
return NULL;
}
/* Close FILE. If FILE was opened for writing, it is written out
now. */
void
lto_obj_file_close (lto_file *file)
{
struct lto_simple_object *lo = (struct lto_simple_object *) file;
if (lo->sobj_r != NULL)
simple_object_release_read (lo->sobj_r);
else if (lo->sobj_w != NULL)
{
const char *errmsg;
int err;
gcc_assert (lo->base.offset == 0);
errmsg = simple_object_write_to_file (lo->sobj_w, lo->fd, &err);
if (errmsg != NULL)
{
if (err == 0)
fatal_error (input_location, "%s", errmsg);
else
fatal_error (input_location, "%s: %s", errmsg, xstrerror (err));
}
simple_object_release_write (lo->sobj_w);
}
if (lo->fd != -1)
{
if (close (lo->fd) < 0)
fatal_error (input_location, "close: %s", xstrerror (errno));
}
}
/* This is passed to lto_obj_add_section. */
struct lto_obj_add_section_data
{
/* The hash table of sections. */
htab_t section_hash_table;
/* The offset of this file. */
off_t base_offset;
/* List in linker order */
struct lto_section_list *list;
};
/* This is called for each section in the file. */
static int
lto_obj_add_section (void *data, const char *name, off_t offset,
off_t length)
{
struct lto_obj_add_section_data *loasd =
(struct lto_obj_add_section_data *) data;
htab_t section_hash_table = (htab_t) loasd->section_hash_table;
char *new_name;
struct lto_section_slot s_slot;
void **slot;
struct lto_section_list *list = loasd->list;
if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
return 1;
new_name = xstrdup (name);
s_slot.name = new_name;
slot = htab_find_slot (section_hash_table, &s_slot, INSERT);
if (*slot == NULL)
{
struct lto_section_slot *new_slot = XCNEW (struct lto_section_slot);
new_slot->name = new_name;
new_slot->start = loasd->base_offset + offset;
new_slot->len = length;
*slot = new_slot;
if (list != NULL)
{
if (!list->first)
list->first = new_slot;
if (list->last)
list->last->next = new_slot;
list->last = new_slot;
}
}
else
{
error ("two or more sections for %s", new_name);
return 0;
}
return 1;
}
/* Build a hash table whose key is the section name and whose data is
the start and size of each section in the .o file. */
htab_t
lto_obj_build_section_table (lto_file *lto_file, struct lto_section_list *list)
{
struct lto_simple_object *lo = (struct lto_simple_object *) lto_file;
htab_t section_hash_table;
struct lto_obj_add_section_data loasd;
const char *errmsg;
int err;
section_hash_table = lto_obj_create_section_hash_table ();
gcc_assert (lo->sobj_r != NULL && lo->sobj_w == NULL);
loasd.section_hash_table = section_hash_table;
loasd.base_offset = lo->base.offset;
loasd.list = list;
errmsg = simple_object_find_sections (lo->sobj_r, lto_obj_add_section,
&loasd, &err);
if (errmsg != NULL)
{
if (err == 0)
error ("%s", errmsg);
else
error ("%s: %s", errmsg, xstrerror (err));
htab_delete (section_hash_table);
return NULL;
}
return section_hash_table;
}
/* The current output file. */
static lto_file *current_out_file;
/* Set the current output file. Return the old one. */
lto_file *
lto_set_current_out_file (lto_file *file)
{
lto_file *old_file;
old_file = current_out_file;
current_out_file = file;
return old_file;
}
/* Return the current output file. */
lto_file *
lto_get_current_out_file (void)
{
return current_out_file;
}
/* Begin writing a new section named NAME in the current output
file. */
void
lto_obj_begin_section (const char *name)
{
struct lto_simple_object *lo;
int align;
const char *errmsg;
int err;
lo = (struct lto_simple_object *) current_out_file;
gcc_assert (lo != NULL
&& lo->sobj_r == NULL
&& lo->sobj_w != NULL
&& lo->section == NULL);
align = ceil_log2 (POINTER_SIZE_UNITS);
lo->section = simple_object_write_create_section (lo->sobj_w, name, align,
&errmsg, &err);
if (lo->section == NULL)
{
if (err == 0)
fatal_error (input_location, "%s", errmsg);
else
fatal_error (input_location, "%s: %s", errmsg, xstrerror (errno));
}
}
/* Add data to a section. BLOCK is a pointer to memory containing
DATA. */
void
lto_obj_append_data (const void *data, size_t len, void *)
{
struct lto_simple_object *lo;
const char *errmsg;
int err;
lo = (struct lto_simple_object *) current_out_file;
gcc_assert (lo != NULL && lo->section != NULL);
errmsg = simple_object_write_add_data (lo->sobj_w, lo->section, data, len,
1, &err);
if (errmsg != NULL)
{
if (err == 0)
fatal_error (input_location, "%s", errmsg);
else
fatal_error (input_location, "%s: %s", errmsg, xstrerror (errno));
}
}
/* Stop writing to the current output section. */
void
lto_obj_end_section (void)
{
struct lto_simple_object *lo;
lo = (struct lto_simple_object *) current_out_file;
gcc_assert (lo != NULL && lo->section != NULL);
lo->section = NULL;
}