+
+
+/*
+ GNU Extension: separate debug-info files
+
+ The idea here is that a special section called .gnu_debuglink might be
+ embedded in a binary file, which indicates that some *other* file
+ contains the real debugging information. This special section contains a
+ filename and CRC32 checksum, which we read and resolve to another file,
+ if it exists.
+
+ This facilitates "optional" provision of debugging information, without
+ having to provide two complete copies of every binary object (with and
+ without debug symbols). */
+
+#define GNU_DEBUGLINK ".gnu_debuglink"
+#define GNU_DEBUGALTLINK ".gnu_debugaltlink"
+
+/*
+FUNCTION
+ bfd_calc_gnu_debuglink_crc32
+
+SYNOPSIS
+ unsigned long bfd_calc_gnu_debuglink_crc32
+ (unsigned long crc, const unsigned char *buf, bfd_size_type len);
+
+DESCRIPTION
+ Computes a CRC value as used in the .gnu_debuglink section.
+ Advances the previously computed @var{crc} value by computing
+ and adding in the crc32 for @var{len} bytes of @var{buf}.
+
+RETURNS
+ Return the updated CRC32 value.
+*/
+
+unsigned long
+bfd_calc_gnu_debuglink_crc32 (unsigned long crc,
+ const unsigned char *buf,
+ bfd_size_type len)
+{
+ static const unsigned long crc32_table[256] =
+ {
+ 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+ 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+ 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+ 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+ 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+ 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+ 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+ 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+ 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+ 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+ 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+ 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+ 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+ 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+ 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+ 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+ 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+ 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+ 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+ 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+ 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+ 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+ 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+ 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+ 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+ 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+ 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+ 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+ 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+ 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+ 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+ 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+ 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+ 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+ 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+ 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+ 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+ 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+ 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+ 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+ 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+ 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+ 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+ 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+ 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+ 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+ 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+ 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+ 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+ 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+ 0x2d02ef8d
+ };
+ const unsigned char *end;
+
+ crc = ~crc & 0xffffffff;
+ for (end = buf + len; buf < end; ++ buf)
+ crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+ return ~crc & 0xffffffff;
+}
+
+
+/*
+INTERNAL_FUNCTION
+ bfd_get_debug_link_info_1
+
+SYNOPSIS
+ char *bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out);
+
+DESCRIPTION
+ Extracts the filename and CRC32 value for any separate debug
+ information file associated with @var{abfd}.
+
+ The @var{crc32_out} parameter is an untyped pointer because
+ this routine is used as a @code{get_func_type} function, but it
+ is expected to be an unsigned long pointer.
+
+RETURNS
+ The filename of the associated debug information file, or NULL
+ if there is no such file. If the filename was found then the
+ contents of @var{crc32_out} are updated to hold the corresponding
+ CRC32 value for the file.
+
+ The returned filename is allocated with @code{malloc}; freeing
+ it is the responsibility of the caller.
+*/
+
+static char *
+bfd_get_debug_link_info_1 (bfd *abfd, void *crc32_out)
+{
+ asection *sect;
+ unsigned long *crc32 = (unsigned long *) crc32_out;
+ bfd_byte *contents;
+ unsigned int crc_offset;
+ char *name;
+
+ BFD_ASSERT (abfd);
+ BFD_ASSERT (crc32_out);
+
+ sect = bfd_get_section_by_name (abfd, GNU_DEBUGLINK);
+
+ if (sect == NULL)
+ return NULL;
+
+ if (!bfd_malloc_and_get_section (abfd, sect, &contents))
+ {
+ if (contents != NULL)
+ free (contents);
+ return NULL;
+ }
+
+ /* CRC value is stored after the filename, aligned up to 4 bytes. */
+ name = (char *) contents;
+ /* PR 17597: avoid reading off the end of the buffer. */
+ crc_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
+ crc_offset = (crc_offset + 3) & ~3;
+ if (crc_offset >= bfd_get_section_size (sect))
+ return NULL;
+
+ *crc32 = bfd_get_32 (abfd, contents + crc_offset);
+ return name;
+}
+
+
+/*
+FUNCTION
+ bfd_get_debug_link_info
+
+SYNOPSIS
+ char *bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out);
+
+DESCRIPTION
+ Extracts the filename and CRC32 value for any separate debug
+ information file associated with @var{abfd}.
+
+RETURNS
+ The filename of the associated debug information file, or NULL
+ if there is no such file. If the filename was found then the
+ contents of @var{crc32_out} are updated to hold the corresponding
+ CRC32 value for the file.
+
+ The returned filename is allocated with @code{malloc}; freeing
+ it is the responsibility of the caller.
+*/
+
+char *
+bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out)
+{
+ return bfd_get_debug_link_info_1 (abfd, crc32_out);
+}
+
+/*
+FUNCTION
+ bfd_get_alt_debug_link_info
+
+SYNOPSIS
+ char *bfd_get_alt_debug_link_info (bfd * abfd,
+ bfd_size_type *buildid_len,
+ bfd_byte **buildid_out);
+
+DESCRIPTION
+ Fetch the filename and BuildID value for any alternate debuginfo
+ associated with @var{abfd}. Return NULL if no such info found,
+ otherwise return filename and update @var{buildid_len} and
+ @var{buildid_out}. The returned filename and build_id are
+ allocated with @code{malloc}; freeing them is the responsibility
+ of the caller.
+*/
+
+char *
+bfd_get_alt_debug_link_info (bfd * abfd, bfd_size_type *buildid_len,
+ bfd_byte **buildid_out)
+{
+ asection *sect;
+ bfd_byte *contents;
+ unsigned int buildid_offset;
+ char *name;
+
+ BFD_ASSERT (abfd);
+ BFD_ASSERT (buildid_len);
+ BFD_ASSERT (buildid_out);
+
+ sect = bfd_get_section_by_name (abfd, GNU_DEBUGALTLINK);
+
+ if (sect == NULL)
+ return NULL;
+
+ if (!bfd_malloc_and_get_section (abfd, sect, & contents))
+ {
+ if (contents != NULL)
+ free (contents);
+ return NULL;
+ }
+
+ /* BuildID value is stored after the filename. */
+ name = (char *) contents;
+ buildid_offset = strnlen (name, bfd_get_section_size (sect)) + 1;
+ if (buildid_offset >= bfd_get_section_size (sect))
+ return NULL;
+
+ *buildid_len = bfd_get_section_size (sect) - buildid_offset;
+ *buildid_out = bfd_malloc (*buildid_len);
+ memcpy (*buildid_out, contents + buildid_offset, *buildid_len);
+
+ return name;
+}
+
+/*
+INTERNAL_FUNCTION
+ separate_debug_file_exists
+
+SYNOPSIS
+ bfd_boolean separate_debug_file_exists
+ (char *name, void *crc32_p);
+
+DESCRIPTION
+ Checks to see if @var{name} is a file and if its contents
+ match @var{crc32}, which is a pointer to an @code{unsigned
+ long} containing a CRC32.
+
+ The @var{crc32_p} parameter is an untyped pointer because
+ this routine is used as a @code{check_func_type} function.
+*/
+
+static bfd_boolean
+separate_debug_file_exists (const char *name, void *crc32_p)
+{
+ static unsigned char buffer [8 * 1024];
+ unsigned long file_crc = 0;
+ FILE *f;
+ bfd_size_type count;
+ unsigned long crc;
+
+ BFD_ASSERT (name);
+ BFD_ASSERT (crc32_p);
+
+ crc = *(unsigned long *) crc32_p;
+
+ f = _bfd_real_fopen (name, FOPEN_RB);
+ if (f == NULL)
+ return FALSE;
+
+ while ((count = fread (buffer, 1, sizeof (buffer), f)) > 0)
+ file_crc = bfd_calc_gnu_debuglink_crc32 (file_crc, buffer, count);
+
+ fclose (f);
+
+ return crc == file_crc;
+}
+
+/*
+INTERNAL_FUNCTION
+ separate_alt_debug_file_exists
+
+SYNOPSIS
+ bfd_boolean separate_alt_debug_file_exists
+ (char *name, void *unused);
+
+DESCRIPTION
+ Checks to see if @var{name} is a file.
+*/
+
+static bfd_boolean
+separate_alt_debug_file_exists (const char *name, void *unused ATTRIBUTE_UNUSED)
+{
+ FILE *f;
+
+ BFD_ASSERT (name);
+
+ f = _bfd_real_fopen (name, FOPEN_RB);
+ if (f == NULL)
+ return FALSE;
+
+ fclose (f);
+
+ return TRUE;
+}
+
+/*
+INTERNAL_FUNCTION
+ find_separate_debug_file
+
+SYNOPSIS
+ char *find_separate_debug_file
+ (bfd *abfd, const char *dir, bfd_boolean include_dirs,
+ get_func_type get, check_func_type check, void *data);
+
+DESCRIPTION
+ Searches for a debug information file corresponding to @var{abfd}.
+
+ The name of the separate debug info file is returned by the
+ @var{get} function. This function scans various fixed locations
+ in the filesystem, including the file tree rooted at @var{dir}.
+ If the @var{include_dirs} parameter is true then the directory
+ components of @var{abfd}'s filename will be included in the
+ searched locations.
+
+ @var{data} is passed unmodified to the @var{get} and @var{check}
+ functions. It is generally used to implement build-id-like
+ matching in the callback functions.
+
+RETURNS
+ Returns the filename of the first file to be found which
+ receives a TRUE result from the @var{check} function.
+ Returns NULL if no valid file could be found.
+*/
+
+typedef char * (* get_func_type) (bfd *, void *);
+typedef bfd_boolean (* check_func_type) (const char *, void *);
+
+static char *
+find_separate_debug_file (bfd * abfd,
+ const char * debug_file_directory,
+ bfd_boolean include_dirs,
+ get_func_type get_func,
+ check_func_type check_func,
+ void * func_data)
+{
+ char *base;
+ char *dir;
+ char *debugfile;
+ char *canon_dir;
+ size_t dirlen;
+ size_t canon_dirlen;
+
+ BFD_ASSERT (abfd);
+ if (debug_file_directory == NULL)
+ debug_file_directory = ".";
+
+ /* BFD may have been opened from a stream. */
+ if (abfd->filename == NULL)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ base = get_func (abfd, func_data);
+
+ if (base == NULL)
+ return NULL;
+
+ if (base[0] == '\0')
+ {
+ free (base);
+ bfd_set_error (bfd_error_no_debug_section);
+ return NULL;
+ }
+
+ if (include_dirs)
+ {
+ for (dirlen = strlen (abfd->filename); dirlen > 0; dirlen--)
+ if (IS_DIR_SEPARATOR (abfd->filename[dirlen - 1]))
+ break;
+
+ dir = (char *) bfd_malloc (dirlen + 1);
+ if (dir == NULL)
+ {
+ free (base);
+ return NULL;
+ }
+ memcpy (dir, abfd->filename, dirlen);
+ dir[dirlen] = '\0';
+ }
+ else
+ {
+ dir = (char *) bfd_malloc (1);
+ * dir = 0;
+ dirlen = 0;
+ }
+
+ /* Compute the canonical name of the bfd object with all symbolic links
+ resolved, for use in the global debugfile directory. */
+ canon_dir = lrealpath (abfd->filename);
+ for (canon_dirlen = strlen (canon_dir); canon_dirlen > 0; canon_dirlen--)
+ if (IS_DIR_SEPARATOR (canon_dir[canon_dirlen - 1]))
+ break;
+ canon_dir[canon_dirlen] = '\0';
+
+#ifndef EXTRA_DEBUG_ROOT1
+#define EXTRA_DEBUG_ROOT1 "/usr/lib/debug"
+#endif
+#ifndef EXTRA_DEBUG_ROOT2
+#define EXTRA_DEBUG_ROOT2 "/usr/lib/debug/usr"
+#endif
+
+ debugfile = (char *)
+ bfd_malloc (strlen (debug_file_directory) + 1
+ + (canon_dirlen > dirlen ? canon_dirlen : dirlen)
+ + strlen (".debug/")
+#ifdef EXTRA_DEBUG_ROOT1
+ + strlen (EXTRA_DEBUG_ROOT1)
+#endif
+#ifdef EXTRA_DEBUG_ROOT2
+ + strlen (EXTRA_DEBUG_ROOT2)
+#endif
+ + strlen (base)
+ + 1);
+ if (debugfile == NULL)
+ goto found; /* Actually this returns NULL. */
+
+ /* First try in the same directory as the original file.
+
+ FIXME: Strictly speaking if we are using the build-id method,
+ (ie include_dirs == FALSE) then we should only check absolute
+ paths, not relative ones like this one (and the next one).
+ The check is left in however as this allows the binutils
+ testsuite to exercise this feature without having to install
+ a file into the root filesystem. (See binutils/testsuite/
+ binutils-all/objdump.exp for the test). */
+ sprintf (debugfile, "%s%s", dir, base);
+ if (check_func (debugfile, func_data))
+ goto found;
+
+ /* Then try in a subdirectory called .debug. */
+ sprintf (debugfile, "%s.debug/%s", dir, base);
+ if (check_func (debugfile, func_data))
+ goto found;
+
+#ifdef EXTRA_DEBUG_ROOT1
+ /* Try the first extra debug file root. */
+ sprintf (debugfile, "%s%s%s", EXTRA_DEBUG_ROOT1,
+ include_dirs ? canon_dir : "/", base);
+ if (check_func (debugfile, func_data))
+ goto found;
+#endif
+
+#ifdef EXTRA_DEBUG_ROOT2
+ /* Try the second extra debug file root. */
+ sprintf (debugfile, "%s%s%s", EXTRA_DEBUG_ROOT2,
+ include_dirs ? canon_dir : "/", base);
+ if (check_func (debugfile, func_data))
+ goto found;
+#endif
+
+ /* Then try in the global debugfile directory. */
+ strcpy (debugfile, debug_file_directory);
+ dirlen = strlen (debug_file_directory) - 1;
+ if (include_dirs)
+ {
+ if (dirlen > 0
+ && debug_file_directory[dirlen] != '/'
+ && canon_dir[0] != '/')
+ strcat (debugfile, "/");
+ strcat (debugfile, canon_dir);
+ }
+ else
+ {
+ if (dirlen > 0 && debug_file_directory[dirlen] != '/')
+ strcat (debugfile, "/");
+ }
+ strcat (debugfile, base);
+
+ if (check_func (debugfile, func_data))
+ goto found;
+
+ /* Failed to find the file. */
+ free (debugfile);
+ debugfile = NULL;
+
+ found:
+ free (base);
+ free (dir);
+ free (canon_dir);
+ return debugfile;
+}
+
+/*
+FUNCTION
+ bfd_follow_gnu_debuglink
+
+SYNOPSIS
+ char *bfd_follow_gnu_debuglink (bfd *abfd, const char *dir);
+
+DESCRIPTION
+ Takes a BFD and searches it for a .gnu_debuglink section. If this
+ section is found, it examines the section for the name and checksum
+ of a '.debug' file containing auxiliary debugging information. It
+ then searches the filesystem for this .debug file in some standard
+ locations, including the directory tree rooted at @var{dir}, and if
+ found returns the full filename.
+
+ If @var{dir} is NULL, the search will take place starting at
+ the current directory.
+
+RETURNS
+ <<NULL>> on any errors or failure to locate the .debug file,
+ otherwise a pointer to a heap-allocated string containing the
+ filename. The caller is responsible for freeing this string.
+*/
+
+char *
+bfd_follow_gnu_debuglink (bfd *abfd, const char *dir)
+{
+ unsigned long crc32;
+
+ return find_separate_debug_file (abfd, dir, TRUE,
+ bfd_get_debug_link_info_1,
+ separate_debug_file_exists, &crc32);
+}
+
+/* Helper for bfd_follow_gnu_debugaltlink. It just returns the name
+ of the separate debug file. */
+
+static char *
+get_alt_debug_link_info_shim (bfd * abfd, void *unused ATTRIBUTE_UNUSED)
+{
+ bfd_size_type len;
+ bfd_byte *buildid = NULL;
+ char *result = bfd_get_alt_debug_link_info (abfd, &len, &buildid);
+
+ free (buildid);
+
+ return result;
+}
+
+/*
+FUNCTION
+ bfd_follow_gnu_debugaltlink
+
+SYNOPSIS
+ char *bfd_follow_gnu_debugaltlink (bfd *abfd, const char *dir);
+
+DESCRIPTION
+ Takes a BFD and searches it for a .gnu_debugaltlink section. If this
+ section is found, it examines the section for the name of a file
+ containing auxiliary debugging information. It then searches the
+ filesystem for this file in a set of standard locations, including
+ the directory tree rooted at @var{dir}, and if found returns the
+ full filename.
+
+ If @var{dir} is NULL, the search will take place starting at
+ the current directory.
+
+RETURNS
+ <<NULL>> on any errors or failure to locate the debug file,
+ otherwise a pointer to a heap-allocated string containing the
+ filename. The caller is responsible for freeing this string.
+*/
+
+char *
+bfd_follow_gnu_debugaltlink (bfd *abfd, const char *dir)
+{
+ return find_separate_debug_file (abfd, dir, TRUE,
+ get_alt_debug_link_info_shim,
+ separate_alt_debug_file_exists,
+ NULL);
+}
+
+/*
+FUNCTION
+ bfd_create_gnu_debuglink_section
+
+SYNOPSIS
+ struct bfd_section *bfd_create_gnu_debuglink_section
+ (bfd *abfd, const char *filename);
+
+DESCRIPTION
+ Takes a @var{BFD} and adds a .gnu_debuglink section to it. The
+ section is sized to be big enough to contain a link to the specified
+ @var{filename}.
+
+RETURNS
+ A pointer to the new section is returned if all is ok. Otherwise
+ <<NULL>> is returned and bfd_error is set.
+*/
+
+asection *
+bfd_create_gnu_debuglink_section (bfd *abfd, const char *filename)
+{
+ asection *sect;
+ bfd_size_type debuglink_size;
+ flagword flags;
+
+ if (abfd == NULL || filename == NULL)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ /* Strip off any path components in filename. */
+ filename = lbasename (filename);
+
+ sect = bfd_get_section_by_name (abfd, GNU_DEBUGLINK);
+ if (sect)
+ {
+ /* Section already exists. */
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ flags = SEC_HAS_CONTENTS | SEC_READONLY | SEC_DEBUGGING;
+ sect = bfd_make_section_with_flags (abfd, GNU_DEBUGLINK, flags);
+ if (sect == NULL)
+ return NULL;
+
+ /* Compute the size of the section. Allow for the CRC after the filename,
+ and padding so that it will start on a 4-byte boundary. */
+ debuglink_size = strlen (filename) + 1;
+ debuglink_size += 3;
+ debuglink_size &= ~3;
+ debuglink_size += 4;
+
+ if (! bfd_set_section_size (abfd, sect, debuglink_size))
+ /* XXX Should we delete the section from the bfd ? */
+ return NULL;
+
+ /* PR 21193: Ensure that the section has 4-byte alignment for the CRC.
+ Note - despite the name of the function being called, we are
+ setting an alignment power, not a byte alignment value. */
+ bfd_set_section_alignment (abfd, sect, 2);
+
+ return sect;
+}
+
+
+/*
+FUNCTION
+ bfd_fill_in_gnu_debuglink_section
+
+SYNOPSIS
+ bfd_boolean bfd_fill_in_gnu_debuglink_section
+ (bfd *abfd, struct bfd_section *sect, const char *filename);
+
+DESCRIPTION
+ Takes a @var{BFD} and containing a .gnu_debuglink section @var{SECT}
+ and fills in the contents of the section to contain a link to the
+ specified @var{filename}. The filename should be relative to the
+ current directory.
+
+RETURNS
+ <<TRUE>> is returned if all is ok. Otherwise <<FALSE>> is returned
+ and bfd_error is set.
+*/
+
+bfd_boolean
+bfd_fill_in_gnu_debuglink_section (bfd *abfd,
+ struct bfd_section *sect,
+ const char *filename)
+{
+ bfd_size_type debuglink_size;
+ unsigned long crc32;
+ char * contents;
+ bfd_size_type crc_offset;
+ FILE * handle;
+ static unsigned char buffer[8 * 1024];
+ size_t count;
+ size_t filelen;
+
+ if (abfd == NULL || sect == NULL || filename == NULL)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return FALSE;
+ }
+
+ /* Make sure that we can read the file.
+ XXX - Should we attempt to locate the debug info file using the same
+ algorithm as gdb ? At the moment, since we are creating the
+ .gnu_debuglink section, we insist upon the user providing us with a
+ correct-for-section-creation-time path, but this need not conform to
+ the gdb location algorithm. */
+ handle = _bfd_real_fopen (filename, FOPEN_RB);
+ if (handle == NULL)
+ {
+ bfd_set_error (bfd_error_system_call);
+ return FALSE;
+ }
+
+ crc32 = 0;
+ while ((count = fread (buffer, 1, sizeof buffer, handle)) > 0)
+ crc32 = bfd_calc_gnu_debuglink_crc32 (crc32, buffer, count);
+ fclose (handle);
+
+ /* Strip off any path components in filename,
+ now that we no longer need them. */
+ filename = lbasename (filename);
+
+ filelen = strlen (filename);
+ debuglink_size = filelen + 1;
+ debuglink_size += 3;
+ debuglink_size &= ~3;
+ debuglink_size += 4;
+
+ contents = (char *) bfd_malloc (debuglink_size);
+ if (contents == NULL)
+ {
+ /* XXX Should we delete the section from the bfd ? */
+ return FALSE;
+ }
+
+ crc_offset = debuglink_size - 4;
+ memcpy (contents, filename, filelen);
+ memset (contents + filelen, 0, crc_offset - filelen);
+
+ bfd_put_32 (abfd, crc32, contents + crc_offset);
+
+ if (! bfd_set_section_contents (abfd, sect, contents, 0, debuglink_size))
+ {
+ /* XXX Should we delete the section from the bfd ? */
+ free (contents);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/*
+INTERNAL_FUNCTION
+ get_build_id
+
+SYNOPSIS
+ struct bfd_build_id * get_build_id (bfd *abfd);
+
+DESCRIPTION
+ Finds the build-id associated with @var{abfd}. If the build-id is
+ extracted from the note section then a build-id structure is built
+ for it, using memory allocated to @var{abfd}, and this is then
+ attached to the @var{abfd}.
+
+RETURNS
+ Returns a pointer to the build-id structure if a build-id could be
+ found. If no build-id is found NULL is returned and error code is
+ set.
+*/
+
+static struct bfd_build_id *
+get_build_id (bfd *abfd)
+{
+ struct bfd_build_id *build_id;
+ Elf_Internal_Note inote;
+ Elf_External_Note *enote;
+ bfd_byte *contents;
+ asection *sect;
+
+ BFD_ASSERT (abfd);
+
+ if (abfd->build_id && abfd->build_id->size > 0)
+ /* Save some time by using the already computed build-id. */
+ return (struct bfd_build_id *) abfd->build_id;
+
+ sect = bfd_get_section_by_name (abfd, ".note.gnu.build-id");
+ if (sect == NULL)
+ {
+ bfd_set_error (bfd_error_no_debug_section);
+ return NULL;
+ }
+
+ /* FIXME: Should we support smaller build-id notes ? */
+ if (bfd_get_section_size (sect) < 0x24)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ if (!bfd_malloc_and_get_section (abfd, sect, & contents))
+ {
+ if (contents != NULL)
+ free (contents);
+ return NULL;
+ }
+
+ enote = (Elf_External_Note *) contents;
+ inote.type = H_GET_32 (abfd, enote->type);
+ inote.namesz = H_GET_32 (abfd, enote->namesz);
+ inote.namedata = enote->name;
+ inote.descsz = H_GET_32 (abfd, enote->descsz);
+ inote.descdata = inote.namedata + BFD_ALIGN (inote.namesz, 4);
+ /* FIXME: Should we check for extra notes in this section ? */
+
+ if (inote.descsz == 0
+ || inote.type != NT_GNU_BUILD_ID
+ || inote.namesz != 4 /* sizeof "GNU" */
+ || strcmp (inote.namedata, "GNU") != 0)
+ {
+ free (contents);
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ build_id = bfd_alloc (abfd, sizeof (struct bfd_build_id) + inote.descsz);
+ if (build_id == NULL)
+ {
+ free (contents);
+ return NULL;
+ }
+
+ build_id->size = inote.descsz;
+ memcpy (build_id->data, inote.descdata, inote.descsz);
+ abfd->build_id = build_id;
+ free (contents);
+
+ return build_id;
+}
+
+/*
+INTERNAL_FUNCTION
+ get_build_id_name
+
+SYNOPSIS
+ char * get_build_id_name (bfd *abfd, void *build_id_out_p)
+
+DESCRIPTION
+ Searches @var{abfd} for a build-id, and then constructs a pathname
+ from it. The path is computed as .build-id/NN/NN+NN.debug where
+ NNNN+NN is the build-id value as a hexadecimal string.
+
+RETURNS
+ Returns the constructed filename or NULL upon error.
+ It is the caller's responsibility to free the memory used to hold the
+ filename.
+ If a filename is returned then the @var{build_id_out_p}
+ parameter (which points to a @code{struct bfd_build_id}
+ pointer) is set to a pointer to the build_id structure.
+*/
+
+static char *
+get_build_id_name (bfd *abfd, void *build_id_out_p)
+{
+ struct bfd_build_id **build_id_out = build_id_out_p;
+ struct bfd_build_id *build_id;
+ char *name;
+ char *n;
+ bfd_size_type s;
+ bfd_byte *d;
+
+ if (abfd == NULL || abfd->filename == NULL || build_id_out == NULL)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return NULL;
+ }
+
+ build_id = get_build_id (abfd);
+ if (build_id == NULL)
+ return NULL;
+
+ /* Compute the debug pathname corresponding to the build-id. */
+ name = bfd_malloc (strlen (".build-id/") + build_id->size * 2 + 2 + strlen (".debug"));
+ if (name == NULL)
+ {
+ bfd_set_error (bfd_error_no_memory);
+ return NULL;
+ }
+ n = name;
+ d = build_id->data;
+ s = build_id->size;
+
+ n += sprintf (n, ".build-id/");
+ n += sprintf (n, "%02x", (unsigned) *d++); s--;
+ n += sprintf (n, "/");
+ while (s--)
+ n += sprintf (n, "%02x", (unsigned) *d++);
+ n += sprintf (n, ".debug");
+
+ *build_id_out = build_id;
+ return name;
+}
+
+/*
+INTERNAL_FUNCTION
+ check_build_id_file
+
+SYNOPSIS
+ bfd_boolean check_build_id_file (char *name, void *buildid_p);
+
+DESCRIPTION
+ Checks to see if @var{name} is a readable file and if its build-id
+ matches @var{buildid}.
+
+RETURNS
+ Returns TRUE if the file exists, is readable, and contains a
+ build-id which matches the build-id pointed at by
+ @var{build_id_p} (which is really a @code{struct bfd_build_id **}).
+*/
+
+static bfd_boolean
+check_build_id_file (const char *name, void *buildid_p)
+{
+ struct bfd_build_id *orig_build_id;
+ struct bfd_build_id *build_id;
+ bfd * file;
+ bfd_boolean result;
+
+ BFD_ASSERT (name);
+ BFD_ASSERT (buildid_p);
+
+ file = bfd_openr (name, NULL);
+ if (file == NULL)
+ return FALSE;
+
+ /* If the file is an archive, process all of its elements. */
+ if (! bfd_check_format (file, bfd_object))
+ {
+ bfd_close (file);
+ return FALSE;
+ }
+
+ build_id = get_build_id (file);
+ if (build_id == NULL)
+ {
+ bfd_close (file);
+ return FALSE;
+ }
+
+ orig_build_id = *(struct bfd_build_id **) buildid_p;
+
+ result = build_id->size == orig_build_id->size
+ && memcmp (build_id->data, orig_build_id->data, build_id->size) == 0;
+
+ (void) bfd_close (file);
+
+ return result;
+}
+
+/*
+FUNCTION
+ bfd_follow_build_id_debuglink
+
+SYNOPSIS
+ char *bfd_follow_build_id_debuglink (bfd *abfd, const char *dir);
+
+DESCRIPTION
+ Takes @var{abfd} and searches it for a .note.gnu.build-id section.
+ If this section is found, it extracts the value of the NT_GNU_BUILD_ID
+ note, which should be a hexadecimal value @var{NNNN+NN} (for
+ 32+ hex digits). It then searches the filesystem for a file named
+ @var{.build-id/NN/NN+NN.debug} in a set of standard locations,
+ including the directory tree rooted at @var{dir}. The filename
+ of the first matching file to be found is returned. A matching
+ file should contain a .note.gnu.build-id section with the same
+ @var{NNNN+NN} note as @var{abfd}, although this check is currently
+ not implemented.
+
+ If @var{dir} is NULL, the search will take place starting at
+ the current directory.
+
+RETURNS
+ <<NULL>> on any errors or failure to locate the debug file,
+ otherwise a pointer to a heap-allocated string containing the
+ filename. The caller is responsible for freeing this string.
+*/
+
+char *
+bfd_follow_build_id_debuglink (bfd *abfd, const char *dir)
+{
+ struct bfd_build_id *build_id;
+
+ return find_separate_debug_file (abfd, dir, FALSE,
+ get_build_id_name,
+ check_build_id_file, &build_id);
+}
projects / deliverable / binutils-gdb.git / blobdiff