Imported binutils-2.20

[msp430-binutils.git] / bfd / compress.c

diff --git a/bfd/compress.c b/bfd/compress.c
new file mode 100644 (file)
index 0000000..5b6ee0e
--- /dev/null
+++ b/bfd/compress.c
@@ -0,0 +1,122 @@
+/* ELF attributes support (based on ARM EABI attributes).
+   Copyright 2008
+   Free Software Foundation, Inc.
+
+   This file is part of BFD, the Binary File Descriptor library.
+
+   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.  */
+
+#include "config.h"
+#include "sysdep.h"
+#include "bfd.h"
+#include "libbfd.h"
+#ifdef HAVE_ZLIB_H
+#include <zlib.h>
+#endif
+
+/*
+FUNCTION
+       bfd_uncompress_section_contents
+
+SYNOPSIS
+       bfd_boolean bfd_uncompress_section_contents
+         (bfd_byte **buffer, bfd_size_type *size);
+
+DESCRIPTION
+
+       Uncompresses a section that was compressed using zlib, in place.  At
+       the call to this function, *@var{buffer} and *@var{size} should point
+       to the section contents to be uncompressed.  At the end of the
+       function, *@var{buffer} and *@var{size} will point to the uncompressed
+       contents.  This function assumes *BUFFER was allocated using
+       bfd_malloc() or equivalent.  If the section is not a valid compressed
+       section, or zlib is not installed on this machine, the input is
+       unmodified.
+
+        Returns @code{FALSE} if unable to uncompress successfully; in that case
+        the input is unmodified.  Otherwise, returns @code{TRUE}.
+*/
+
+bfd_boolean
+bfd_uncompress_section_contents (bfd_byte **buffer, bfd_size_type *size)
+{
+#ifndef HAVE_ZLIB_H
+  /* These are just to quiet gcc.  */
+  buffer = 0;
+  size = 0;
+  return FALSE;
+#else
+  bfd_size_type compressed_size = *size;
+  bfd_byte *compressed_buffer = *buffer;
+  bfd_size_type uncompressed_size;
+  bfd_byte *uncompressed_buffer;
+  z_stream strm;
+  int rc;
+  bfd_size_type header_size = 12;
+
+  /* Read the zlib header.  In this case, it should be "ZLIB" followed
+     by the uncompressed section size, 8 bytes in big-endian order.  */
+  if (compressed_size < header_size
+      || ! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
+    return FALSE;
+  uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
+  uncompressed_size += compressed_buffer[11];
+
+  /* It is possible the section consists of several compressed
+     buffers concatenated together, so we uncompress in a loop.  */
+  strm.zalloc = NULL;
+  strm.zfree = NULL;
+  strm.opaque = NULL;
+  strm.avail_in = compressed_size - header_size;
+  strm.next_in = (Bytef*) compressed_buffer + header_size;
+  strm.avail_out = uncompressed_size;
+  uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
+  if (! uncompressed_buffer)
+    return FALSE;
+
+  rc = inflateInit (&strm);
+  while (strm.avail_in > 0)
+    {
+      if (rc != Z_OK)
+        goto fail;
+      strm.next_out = ((Bytef*) uncompressed_buffer
+                       + (uncompressed_size - strm.avail_out));
+      rc = inflate (&strm, Z_FINISH);
+      if (rc != Z_STREAM_END)
+        goto fail;
+      rc = inflateReset (&strm);
+    }
+  rc = inflateEnd (&strm);
+  if (rc != Z_OK
+      || strm.avail_out != 0)
+    goto fail;
+
+  free (compressed_buffer);
+  *buffer = uncompressed_buffer;
+  *size = uncompressed_size;
+  return TRUE;
+
+ fail:
+  free (uncompressed_buffer);
+  return FALSE;
+#endif  /* HAVE_ZLIB_H */
+}