gcc/libiberty/simple-object.c

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/* simple-object.c -- simple routines to read and write object files.
Copyright 2010 Free Software Foundation, Inc.
Written by Ian Lance Taylor, Google.
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, 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, 51 Franklin Street - Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "config.h"
#include "libiberty.h"
#include "simple-object.h"
#include <errno.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
#include "simple-object-common.h"
/* The known object file formats. */
static const struct simple_object_functions * const format_functions[] =
{
&simple_object_elf_functions,
&simple_object_mach_o_functions,
&simple_object_coff_functions
};
/* Read data from a file using the simple_object error reporting
conventions. */
int
simple_object_internal_read (int descriptor, off_t offset,
unsigned char *buffer, size_t size,
const char **errmsg, int *err)
{
ssize_t got;
if (lseek (descriptor, offset, SEEK_SET) < 0)
{
*errmsg = "lseek";
*err = errno;
return 0;
}
got = read (descriptor, buffer, size);
if (got < 0)
{
*errmsg = "read";
*err = errno;
return 0;
}
if ((size_t) got < size)
{
*errmsg = "file too short";
*err = 0;
return 0;
}
return 1;
}
/* Write data to a file using the simple_object error reporting
conventions. */
int
simple_object_internal_write (int descriptor, off_t offset,
const unsigned char *buffer, size_t size,
const char **errmsg, int *err)
{
ssize_t wrote;
if (lseek (descriptor, offset, SEEK_SET) < 0)
{
*errmsg = "lseek";
*err = errno;
return 0;
}
wrote = write (descriptor, buffer, size);
if (wrote < 0)
{
*errmsg = "write";
*err = errno;
return 0;
}
if ((size_t) wrote < size)
{
*errmsg = "short write";
*err = 0;
return 0;
}
return 1;
}
/* Open for read. */
simple_object_read *
simple_object_start_read (int descriptor, off_t offset,
const char *segment_name, const char **errmsg,
int *err)
{
unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN];
size_t len, i;
if (!simple_object_internal_read (descriptor, offset, header,
SIMPLE_OBJECT_MATCH_HEADER_LEN,
errmsg, err))
return NULL;
len = sizeof (format_functions) / sizeof (format_functions[0]);
for (i = 0; i < len; ++i)
{
void *data;
data = format_functions[i]->match (header, descriptor, offset,
segment_name, errmsg, err);
if (data != NULL)
{
simple_object_read *ret;
ret = XNEW (simple_object_read);
ret->descriptor = descriptor;
ret->offset = offset;
ret->functions = format_functions[i];
ret->data = data;
return ret;
}
}
*errmsg = "file not recognized";
*err = 0;
return NULL;
}
/* Find all sections. */
const char *
simple_object_find_sections (simple_object_read *sobj,
int (*pfn) (void *, const char *, off_t, off_t),
void *data,
int *err)
{
return sobj->functions->find_sections (sobj, pfn, data, err);
}
/* Internal data passed to find_one_section. */
struct find_one_section_data
{
/* The section we are looking for. */
const char *name;
/* Where to store the section offset. */
off_t *offset;
/* Where to store the section length. */
off_t *length;
/* Set if the name is found. */
int found;
};
/* Internal function passed to find_sections. */
static int
find_one_section (void *data, const char *name, off_t offset, off_t length)
{
struct find_one_section_data *fosd = (struct find_one_section_data *) data;
if (strcmp (name, fosd->name) != 0)
return 1;
*fosd->offset = offset;
*fosd->length = length;
fosd->found = 1;
/* Stop iteration. */
return 0;
}
/* Find a section. */
int
simple_object_find_section (simple_object_read *sobj, const char *name,
off_t *offset, off_t *length,
const char **errmsg, int *err)
{
struct find_one_section_data fosd;
fosd.name = name;
fosd.offset = offset;
fosd.length = length;
fosd.found = 0;
*errmsg = simple_object_find_sections (sobj, find_one_section,
(void *) &fosd, err);
if (*errmsg != NULL)
return 0;
if (!fosd.found)
return 0;
return 1;
}
/* Fetch attributes. */
simple_object_attributes *
simple_object_fetch_attributes (simple_object_read *sobj, const char **errmsg,
int *err)
{
void *data;
simple_object_attributes *ret;
data = sobj->functions->fetch_attributes (sobj, errmsg, err);
if (data == NULL)
return NULL;
ret = XNEW (simple_object_attributes);
ret->functions = sobj->functions;
ret->data = data;
return ret;
}
/* Release an simple_object_read. */
void
simple_object_release_read (simple_object_read *sobj)
{
sobj->functions->release_read (sobj->data);
XDELETE (sobj);
}
/* Merge attributes. */
const char *
simple_object_attributes_merge (simple_object_attributes *to,
simple_object_attributes *from,
int *err)
{
if (to->functions != from->functions)
{
*err = 0;
return "different object file format";
}
return to->functions->attributes_merge (to->data, from->data, err);
}
/* Release an attributes structure. */
void
simple_object_release_attributes (simple_object_attributes *attrs)
{
attrs->functions->release_attributes (attrs->data);
XDELETE (attrs);
}
/* Start creating an object file. */
simple_object_write *
simple_object_start_write (simple_object_attributes *attrs,
const char *segment_name, const char **errmsg,
int *err)
{
void *data;
simple_object_write *ret;
data = attrs->functions->start_write (attrs->data, errmsg, err);
if (data == NULL)
return NULL;
ret = XNEW (simple_object_write);
ret->functions = attrs->functions;
ret->segment_name = xstrdup (segment_name);
ret->sections = NULL;
ret->last_section = NULL;
ret->data = data;
return ret;
}
/* Start creating a section. */
simple_object_write_section *
simple_object_write_create_section (simple_object_write *sobj, const char *name,
unsigned int align,
const char **errmsg ATTRIBUTE_UNUSED,
int *err ATTRIBUTE_UNUSED)
{
simple_object_write_section *ret;
ret = XNEW (simple_object_write_section);
ret->next = NULL;
ret->name = xstrdup (name);
ret->align = align;
ret->buffers = NULL;
ret->last_buffer = NULL;
if (sobj->last_section == NULL)
{
sobj->sections = ret;
sobj->last_section = ret;
}
else
{
sobj->last_section->next = ret;
sobj->last_section = ret;
}
return ret;
}
/* Add data to a section. */
const char *
simple_object_write_add_data (simple_object_write *sobj ATTRIBUTE_UNUSED,
simple_object_write_section *section,
const void *buffer,
size_t size, int copy,
int *err ATTRIBUTE_UNUSED)
{
struct simple_object_write_section_buffer *wsb;
wsb = XNEW (struct simple_object_write_section_buffer);
wsb->next = NULL;
wsb->size = size;
if (!copy)
{
wsb->buffer = buffer;
wsb->free_buffer = NULL;
}
else
{
wsb->free_buffer = (void *) XNEWVEC (char, size);
memcpy (wsb->free_buffer, buffer, size);
wsb->buffer = wsb->free_buffer;
}
if (section->last_buffer == NULL)
{
section->buffers = wsb;
section->last_buffer = wsb;
}
else
{
section->last_buffer->next = wsb;
section->last_buffer = wsb;
}
return NULL;
}
/* Write the complete object file. */
const char *
simple_object_write_to_file (simple_object_write *sobj, int descriptor,
int *err)
{
return sobj->functions->write_to_file (sobj, descriptor, err);
}
/* Release an simple_object_write. */
void
simple_object_release_write (simple_object_write *sobj)
{
simple_object_write_section *section;
free (sobj->segment_name);
section = sobj->sections;
while (section != NULL)
{
struct simple_object_write_section_buffer *buffer;
simple_object_write_section *next_section;
buffer = section->buffers;
while (buffer != NULL)
{
struct simple_object_write_section_buffer *next_buffer;
if (buffer->free_buffer != NULL)
XDELETEVEC (buffer->free_buffer);
next_buffer = buffer->next;
XDELETE (buffer);
buffer = next_buffer;
}
next_section = section->next;
free (section->name);
XDELETE (section);
section = next_section;
}
sobj->functions->release_write (sobj->data);
XDELETE (sobj);
}