#include "libiberty.h"
#include "safe-ctype.h"
#include "getopt.h"
+#include "md5.h"
+#include "sha1.h"
+#include <fcntl.h>
#include "bfdlink.h"
if test x"$LDEMUL_AFTER_OPEN" != xgld"$EMULATION_NAME"_after_open; then
cat >>e${EMULATION_NAME}.c <<EOF
+static bfd_size_type
+gld${EMULATION_NAME}_id_note_section_size (bfd *abfd,
+ struct bfd_link_info *link_info)
+{
+ const char *style = link_info->emit_note_gnu_build_id;
+ bfd_size_type size;
+
+ abfd = abfd;
+
+ size = offsetof (Elf_External_Note, name[sizeof "GNU"]);
+ size = (size + 3) & -(bfd_size_type) 4;
+
+ if (!strcmp (style, "md5") || !strcmp (style, "uuid"))
+ size += 128 / 8;
+ else if (!strcmp (style, "sha1"))
+ size += 160 / 8;
+ else if (!strncmp (style, "0x", 2))
+ {
+ /* ID is in string form (hex). Convert to bits. */
+ const char *id = style + 2;
+ do
+ {
+ if (ISXDIGIT (id[0]) && ISXDIGIT (id[1]))
+ {
+ ++size;
+ id += 2;
+ }
+ else if (*id == '-' || *id == ':')
+ ++id;
+ else
+ {
+ size = 0;
+ break;
+ }
+ } while (*id != '\0');
+ }
+ else
+ size = 0;
+
+ return size;
+}
+
+static unsigned char
+read_hex (const char xdigit)
+{
+ if (ISDIGIT (xdigit))
+ return xdigit - '0';
+ if (ISUPPER (xdigit))
+ return xdigit - 'A' + 0xa;
+ if (ISLOWER (xdigit))
+ return xdigit - 'a' + 0xa;
+ abort ();
+ return 0;
+}
+
+struct build_id_info
+{
+ const char *style;
+ asection *sec;
+};
+
+static bfd_boolean
+gld${EMULATION_NAME}_write_build_id_section (bfd *abfd)
+{
+ const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+ struct build_id_info *info =
+ elf_tdata (abfd)->after_write_object_contents_info;
+ asection *asec;
+ Elf_Internal_Shdr *i_shdr;
+ unsigned char *contents, *id_bits;
+ bfd_size_type size;
+ Elf_External_Note *e_note;
+
+ asec = info->sec;
+ if (asec->output_section == NULL)
+ {
+ einfo (_("%P: .note.gnu.build-id section missing"));
+ return FALSE;
+ }
+ i_shdr = &elf_section_data (asec->output_section)->this_hdr;
+
+ if (i_shdr->contents == NULL)
+ {
+ ASSERT (asec->output_offset == 0);
+ i_shdr->contents = xcalloc (i_shdr->sh_size, 1);
+ if (i_shdr->contents == NULL)
+ return FALSE;
+ }
+ contents = i_shdr->contents + asec->output_offset;
+
+ e_note = (void *) contents;
+ size = offsetof (Elf_External_Note, name[sizeof "GNU"]);
+ size = (size + 3) & -(bfd_size_type) 4;
+ id_bits = contents + size;
+ size = asec->size - size;
+
+ bfd_h_put_32 (abfd, sizeof "GNU", &e_note->namesz);
+ bfd_h_put_32 (abfd, size, &e_note->descsz);
+ bfd_h_put_32 (abfd, NT_GNU_BUILD_ID, &e_note->type);
+ memcpy (e_note->name, "GNU", sizeof "GNU");
+
+ if (!strcmp (info->style, "md5"))
+ {
+ struct md5_ctx ctx;
+ md5_init_ctx (&ctx);
+ if (bed->s->checksum_contents (abfd,
+ (void (*) (const void *, size_t, void *))
+ &md5_process_bytes,
+ &ctx))
+ md5_finish_ctx (&ctx, id_bits);
+ else
+ return FALSE;
+ }
+ else if (!strcmp (info->style, "sha1"))
+ {
+ struct sha1_ctx ctx;
+ sha1_init_ctx (&ctx);
+ if (bed->s->checksum_contents (abfd,
+ (void (*) (const void *, size_t, void *))
+ &sha1_process_bytes,
+ &ctx))
+ sha1_finish_ctx (&ctx, id_bits);
+ else
+ return FALSE;
+ }
+ else if (!strcmp (info->style, "uuid"))
+ {
+ int n;
+ int fd = open ("/dev/urandom", O_RDONLY);
+ if (fd < 0)
+ return FALSE;
+ n = read (fd, id_bits, size);
+ close (fd);
+ if (n < (int) size)
+ return FALSE;
+ }
+ else if (!strncmp (info->style, "0x", 2))
+ {
+ /* ID is in string form (hex). Convert to bits. */
+ const char *id = info->style + 2;
+ size_t n = 0;
+ do
+ {
+ if (ISXDIGIT (id[0]) && ISXDIGIT (id[1]))
+ {
+ id_bits[n] = read_hex (*id++) << 4;
+ id_bits[n++] |= read_hex (*id++);
+ }
+ else if (*id == '-' || *id == ':')
+ ++id;
+ else
+ abort (); /* Should have been validated earlier. */
+ } while (*id != '\0');
+ }
+ else
+ abort (); /* Should have been validated earlier. */
+
+ size = i_shdr->sh_size;
+ return (bfd_seek (abfd, i_shdr->sh_offset, SEEK_SET) == 0
+ && bfd_bwrite (i_shdr->contents, size, abfd) == size);
+}
+
+
/* This is called after all the input files have been opened. */
static void
abfd = link_info.input_bfds;
- size = _bfd_id_note_section_size (abfd, &link_info);
+ size = gld${EMULATION_NAME}_id_note_section_size (abfd, &link_info);
if (size == 0)
{
einfo ("%P: warning: unrecognized --build-id style ignored.\n");
if (s != NULL && bfd_set_section_alignment (abfd, s, 2))
{
struct elf_obj_tdata *t = elf_tdata (output_bfd);
- t->emit_note_gnu_build_id = link_info.emit_note_gnu_build_id;
- t->note_gnu_build_id_sec = s;
+ struct build_id_info *b = xmalloc (sizeof *b);
+ b->style = link_info.emit_note_gnu_build_id;
+ b->sec = s;
elf_section_type (s) = SHT_NOTE;
s->size = size;
+ t->after_write_object_contents
+ = &gld${EMULATION_NAME}_write_build_id_section;
+ t->after_write_object_contents_info = b;
}
else
{
memcpy (*longopts + nl, &xtra_long, sizeof (xtra_long));
}
-#define DEFAULT_BUILD_ID_STYLE "md5"
+#define DEFAULT_BUILD_ID_STYLE "sha1"
static bfd_boolean
gld${EMULATION_NAME}_handle_option (int optc)
Request creation of @code{.note.gnu.build-id} ELF note section.
The contents of the note are unique bits identifying this linked
file. @var{style} can be @code{uuid} to use 128 random bits,
-@code{md5} to use a 128-bit @sc{MD5} hash on the normative parts
-of the output contents, or @code{0x@var{hexstring}} to use a
-chosen bit string specified as an even number of hexadecimal
-digits (@code{-} and @code{:} characters between digit pairs are
-ignored). If @var{style} is omitted, @code{md5} is used.
-
-The @code{md5} style produces an identifier that is always the
-same in an identical output file, but will be unique among all
-nonidentical output files. It is not intended to be compared as
-a checksum for the file's contents. A linked file may be
-changed later by other tools, but the build ID bit string
-identifying the original linked file does not change.
+@code{sha1} to use a 160-bit @sc{SHA1} hash on the normative
+parts of the output contents, @code{md5} to use a 128-bit
+@sc{MD5} hash on the normative parts of the output contents, or
+@code{0x@var{hexstring}} to use a chosen bit string specified as
+an even number of hexadecimal digits (@code{-} and @code{:}
+characters between digit pairs are ignored). If @var{style} is
+omitted, @code{sha1} is used.
+
+The @code{md5} and @code{sha1} styles produces an identifier
+that is always the same in an identical output file, but will be
+unique among all nonidentical output files. It is not intended
+to be compared as a checksum for the file's contents. A linked
+file may be changed later by other tools, but the build ID bit
+string identifying the original linked file does not change.
Passing @code{none} for @var{style} disables the setting from any
@code{--build-id} options earlier on the command line.
projects / binutils-gdb.git / commitdiff