Fix elf64-ppc.c electric fence warning

[deliverable/binutils-gdb.git] / bfd / compress.c

diff --git a/bfd/compress.c b/bfd/compress.c
index 294bfd3e9df94ccf2d28479e7967885a386a6747..0087a665d87b3357e0ba190acdc347892bd944ca 100644 (file)
--- a/bfd/compress.c
+++ b/bfd/compress.c
@@ -1,6 +1,5 @@
 /* Compressed section support (intended for debug sections).
-   Copyright 2008, 2010, 2011, 2012
-   Free Software Foundation, Inc.
+   Copyright (C) 2008-2015 Free Software Foundation, Inc.
 
    This file is part of BFD, the Binary File Descriptor library.
 
@@ -25,6 +24,7 @@
 #ifdef HAVE_ZLIB_H
 #include <zlib.h>
 #endif
+#include "safe-ctype.h"
 
 #ifdef HAVE_ZLIB_H
 static bfd_boolean
@@ -45,19 +45,20 @@ decompress_contents (bfd_byte *compressed_buffer,
   strm.next_in = (Bytef*) compressed_buffer + 12;
   strm.avail_out = uncompressed_size;
 
+  BFD_ASSERT (Z_OK == 0);
   rc = inflateInit (&strm);
   while (strm.avail_in > 0 && strm.avail_out > 0)
     {
       if (rc != Z_OK)
-       return FALSE;
+       break;
       strm.next_out = ((Bytef*) uncompressed_buffer
                        + (uncompressed_size - strm.avail_out));
       rc = inflate (&strm, Z_FINISH);
       if (rc != Z_STREAM_END)
-       return FALSE;
+       break;
       rc = inflateReset (&strm);
     }
-  rc = inflateEnd (&strm);
+  rc |= inflateEnd (&strm);
   return rc == Z_OK && strm.avail_out == 0;
 }
 #endif
@@ -79,7 +80,7 @@ DESCRIPTION
        field was allocated using bfd_malloc() or equivalent.  If zlib
        is not installed on this machine, the input is unmodified.
 
-       Return @code{TRUE} if the full section contents is compressed 
+       Return @code{TRUE} if the full section contents is compressed
        successfully.
 */
 
@@ -148,10 +149,11 @@ SYNOPSIS
 DESCRIPTION
        Read all data from @var{section} in BFD @var{abfd}, decompress
        if needed, and store in @var{*ptr}.  If @var{*ptr} is NULL,
-       return @var{*ptr} with memory malloc'd by this function.  
+       return @var{*ptr} with memory malloc'd by this function.
 
        Return @code{TRUE} if the full section contents is retrieved
-       successfully.
+       successfully.  If the section has no contents then this function
+       returns @code{TRUE} but @var{*ptr} is set to NULL.
 */
 
 bfd_boolean
@@ -171,7 +173,10 @@ bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
   else
     sz = sec->size;
   if (sz == 0)
-    return TRUE;
+    {
+      *ptr = NULL;
+      return TRUE;
+    }
 
   switch (sec->compress_status)
     {
@@ -182,6 +187,7 @@ bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
          if (p == NULL)
            return FALSE;
        }
+
       if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
        {
          if (*ptr != p)
@@ -238,6 +244,8 @@ bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
 #endif
 
     case COMPRESS_SECTION_DONE:
+      if (sec->contents == NULL)
+       return FALSE;
       if (p == NULL)
        {
          p = (bfd_byte *) bfd_malloc (sz);
@@ -245,7 +253,9 @@ bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
            return FALSE;
          *ptr = p;
        }
-      memcpy (p, sec->contents, sz);
+      /* PR 17512; file: 5bc29788.  */
+      if (p != sec->contents)
+       memcpy (p, sec->contents, sz);
       return TRUE;
 
     default:
@@ -253,6 +263,29 @@ bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
     }
 }
 
+/*
+FUNCTION
+       bfd_cache_section_contents
+
+SYNOPSIS
+       void bfd_cache_section_contents
+         (asection *sec, void *contents);
+
+DESCRIPTION
+       Stash @var(contents) so any following reads of @var(sec) do
+       not need to decompress again.
+*/
+
+void
+bfd_cache_section_contents (asection *sec, void *contents)
+{
+  if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
+    sec->compress_status = COMPRESS_SECTION_DONE;
+  sec->contents = contents;
+  sec->flags |= SEC_IN_MEMORY;
+}
+
+
 /*
 FUNCTION
        bfd_is_section_compressed
@@ -269,11 +302,29 @@ bfd_boolean
 bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
 {
   bfd_byte compressed_buffer [12];
+  unsigned int saved = sec->compress_status;
+  bfd_boolean compressed;
+
+  /* Don't decompress the section.  */
+  sec->compress_status = COMPRESS_SECTION_NONE;
 
   /* Read the zlib header.  In this case, it should be "ZLIB" followed
      by the uncompressed section size, 8 bytes in big-endian order.  */
-  return (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
-         && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
+  compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
+               && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
+
+  /* Check for the pathalogical case of a debug string section that
+     contains the string ZLIB.... as the first entry.  We assume that
+     no uncompressed .debug_str section would ever be big enough to
+     have the first byte of its (big-endian) size be non-zero.  */
+  if (compressed
+      && strcmp (sec->name, ".debug_str") == 0
+      && ISPRINT (compressed_buffer[4]))
+    compressed = FALSE;
+
+  /* Restore compress_status.  */
+  sec->compress_status = saved;
+  return compressed;
 }
 
 /*