Properly convert objects between different ELF classes

[thirdparty/binutils-gdb.git] / bfd / bfd.c

diff --git a/bfd/bfd.c b/bfd/bfd.c
index 8d85de50b970580cc093bca7f884dd7e42ba2271..846ab58ac1a2d8d9aac9164f9ed20754b35d73cd 100644 (file)
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -2111,3 +2111,158 @@ bfd_get_compression_header_size (bfd *abfd, asection *sec)
 
   return 0;
 }
+
+/*
+FUNCTION
+       bfd_convert_section_size
+
+SYNOPSIS
+       bfd_size_type bfd_convert_section_size
+         (bfd *ibfd, asection *isec, bfd *obfd, bfd_size_type size);
+
+DESCRIPTION
+       Convert the size @var{size} of the section @var{isec} in input
+       BFD @var{ibfd} to the section size in output BFD @var{obfd}.
+*/
+
+bfd_size_type
+bfd_convert_section_size (bfd *ibfd, sec_ptr isec, bfd *obfd,
+                         bfd_size_type size)
+{
+  bfd_size_type hdr_size;
+
+  /* Do nothing if input file will be decompressed.  */
+  if ((ibfd->flags & BFD_DECOMPRESS))
+    return size;
+
+  /* Do nothing if either input or output aren't ELF.  */
+  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
+      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
+    return size;
+
+  /* Do nothing if ELF classes of input and output are the same. */
+  if (get_elf_backend_data (ibfd)->s->elfclass
+      == get_elf_backend_data (obfd)->s->elfclass)
+    return size;
+
+  /* Do nothing if the input section isn't a SHF_COMPRESSED section. */
+  hdr_size = bfd_get_compression_header_size (ibfd, isec);
+  if (hdr_size == 0)
+    return size;
+
+  /* Adjust the size of the output SHF_COMPRESSED section.  */
+  if (hdr_size == sizeof (Elf32_External_Chdr))
+    return (size - sizeof (Elf32_External_Chdr)
+           + sizeof (Elf64_External_Chdr));
+  else
+    return (size - sizeof (Elf64_External_Chdr)
+           + sizeof (Elf32_External_Chdr));
+}
+
+/*
+FUNCTION
+       bfd_convert_section_contents
+
+SYNOPSIS
+       bfd_boolean bfd_convert_section_contents
+         (bfd *ibfd, asection *isec, bfd *obfd, bfd_byte **ptr);
+
+DESCRIPTION
+       Convert the contents, stored in @var{*ptr}, of the section
+       @var{isec} in input BFD @var{ibfd} to output BFD @var{obfd}
+       if needed.  The original buffer pointed to by @var{*ptr} may
+       be freed and @var{*ptr} is returned with memory malloc'd by this
+       function.
+*/
+
+bfd_boolean
+bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd,
+                             bfd_byte **ptr)
+{
+  bfd_byte *contents;
+  bfd_size_type ihdr_size, ohdr_size, size;
+  Elf_Internal_Chdr chdr;
+  bfd_boolean use_memmove;
+
+  /* Do nothing if input file will be decompressed.  */
+  if ((ibfd->flags & BFD_DECOMPRESS))
+    return TRUE;
+
+  /* Do nothing if either input or output aren't ELF.  */
+  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
+      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
+    return TRUE;
+
+  /* Do nothing if ELF classes of input and output are the same. */
+  if (get_elf_backend_data (ibfd)->s->elfclass
+      == get_elf_backend_data (obfd)->s->elfclass)
+    return TRUE;
+
+  /* Do nothing if the input section isn't a SHF_COMPRESSED section. */
+  ihdr_size = bfd_get_compression_header_size (ibfd, isec);
+  if (ihdr_size == 0)
+    return TRUE;
+
+  contents = *ptr;
+
+  /* Convert the contents of the input SHF_COMPRESSED section to
+     output.  Get the input compression header and the size of the
+     output compression header.  */
+  if (ihdr_size == sizeof (Elf32_External_Chdr))
+    {
+      Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents;
+      chdr.ch_type = bfd_get_32 (ibfd, &echdr->ch_type);
+      chdr.ch_size = bfd_get_32 (ibfd, &echdr->ch_size);
+      chdr.ch_addralign = bfd_get_32 (ibfd, &echdr->ch_addralign);
+
+      ohdr_size = sizeof (Elf64_External_Chdr);
+
+      use_memmove = FALSE;
+    }
+  else
+    {
+      Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents;
+      chdr.ch_type = bfd_get_64 (ibfd, &echdr->ch_type);
+      chdr.ch_size = bfd_get_64 (ibfd, &echdr->ch_size);
+      chdr.ch_addralign = bfd_get_64 (ibfd, &echdr->ch_addralign);
+
+      ohdr_size = sizeof (Elf32_External_Chdr);
+      use_memmove = TRUE;
+    }
+
+  size = bfd_get_section_size (isec) - ihdr_size + ohdr_size;
+  if (!use_memmove)
+    {
+      contents = (bfd_byte *) bfd_malloc (size);
+      if (contents == NULL)
+       return FALSE;
+    }
+
+  /* Write out the output compression header.  */
+  if (ohdr_size == sizeof (Elf32_External_Chdr))
+    {
+      Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents;
+      bfd_put_32 (obfd, ELFCOMPRESS_ZLIB, &echdr->ch_type);
+      bfd_put_32 (obfd, chdr.ch_size, &echdr->ch_size);
+      bfd_put_32 (obfd, chdr.ch_addralign, &echdr->ch_addralign);
+    }
+  else
+    {
+      Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents;
+      bfd_put_64 (obfd, ELFCOMPRESS_ZLIB, &echdr->ch_type);
+      bfd_put_64 (obfd, chdr.ch_size, &echdr->ch_size);
+      bfd_put_64 (obfd, chdr.ch_addralign, &echdr->ch_addralign);
+    }
+
+  /* Copy the compressed contents.  */
+  if (use_memmove)
+    memmove (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size);
+  else
+    {
+      memcpy (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size);
+      free (*ptr);
+      *ptr = contents;
+    }
+
+  return TRUE;
+}