From 95e34fb4f43f5cc57c48d4799c5c59d7dcf6c2a2 Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Wed, 29 May 2013 14:58:35 +0000 Subject: [PATCH] * dwarf2.c (struct dwarf2_debug): Add fields for handling alternate debug info source. (dwarf_debug_sections): Add entries for alternate .debug_str and .debug_info sections. (dwarf_debug_section_enum): Likewise. (read_alt_indirect_string): New function. Handles a DW_FORM_GNU_strp_alt attribute. (read_alt_indirect_ref): New function. Handles a DW_FORM_GNU_ref_alt attribute. (read_attribute_value): Process DW_FORM_GNU_ref_alt and DW_FORM_GNU_strp_alt. (find_abstract_instance_name): Handle DW_FORM_GNU_ref_alt attributes. (_bfd_dwarf2_cleanup_debug_info): Free alternate debug info sources. * opncls.c (GNU_DEBUGALTLINK): Define. (bfd_get_alt_debug_link_info): New function. (separate_alt_debug_file_exists): New function. (find_separate_debug_file): Add parameters for fetch and check functions. (bfd_follow_gnu_debugaltlink): New function. * bfd-in2.h: Regenerate. --- bfd/ChangeLog | 25 ++++++++ bfd/bfd-in2.h | 4 ++ bfd/dwarf2.c | 148 +++++++++++++++++++++++++++++++++++++++++++-- bfd/opncls.c | 189 +++++++++++++++++++++++++++++++++++++++++++++------------- 4 files changed, 320 insertions(+), 46 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 5169996..d1ec430 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,28 @@ +2013-05-29 Nick Clifton + + * dwarf2.c (struct dwarf2_debug): Add fields for handling + alternate debug info source. + (dwarf_debug_sections): Add entries for alternate .debug_str and + .debug_info sections. + (dwarf_debug_section_enum): Likewise. + (read_alt_indirect_string): New function. Handles a + DW_FORM_GNU_strp_alt attribute. + (read_alt_indirect_ref): New function. Handles a + DW_FORM_GNU_ref_alt attribute. + (read_attribute_value): Process DW_FORM_GNU_ref_alt and + DW_FORM_GNU_strp_alt. + (find_abstract_instance_name): Handle DW_FORM_GNU_ref_alt + attributes. + (_bfd_dwarf2_cleanup_debug_info): Free alternate debug info + sources. + * opncls.c (GNU_DEBUGALTLINK): Define. + (bfd_get_alt_debug_link_info): New function. + (separate_alt_debug_file_exists): New function. + (find_separate_debug_file): Add parameters for fetch and check + functions. + (bfd_follow_gnu_debugaltlink): New function. + * bfd-in2.h: Regenerate. + 2013-05-28 Yufeng Zhang * reloc.c (BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE): Rename to ... diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index a6299a5..efc1a55 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -1051,8 +1051,12 @@ unsigned long bfd_calc_gnu_debuglink_crc32 char *bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out); +char *bfd_get_alt_debug_link_info (bfd *abfd, unsigned long *crc32_out); + char *bfd_follow_gnu_debuglink (bfd *abfd, const char *dir); +char *bfd_follow_gnu_debugaltlink (bfd *abfd, const char *dir); + struct bfd_section *bfd_create_gnu_debuglink_section (bfd *abfd, const char *filename); diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c index 7a1a4ae..c9349da 100644 --- a/bfd/dwarf2.c +++ b/bfd/dwarf2.c @@ -1,6 +1,5 @@ /* DWARF 2 support. - Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, - 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. + Copyright 1994-2013 Free Software Foundation, Inc. Adapted from gdb/dwarf2read.c by Gavin Koch of Cygnus Solutions (gavin@cygnus.com). @@ -108,6 +107,16 @@ struct dwarf2_debug asection *sec; bfd_byte *sec_info_ptr; + /* Support for alternate debug info sections created by the DWZ utility: + This includes a pointer to an alternate bfd which contains *extra*, + possibly duplicate debug sections, and pointers to the loaded + .debug_str and .debug_info sections from this bfd. */ + bfd * alt_bfd_ptr; + bfd_byte * alt_dwarf_str_buffer; + bfd_size_type alt_dwarf_str_size; + bfd_byte * alt_dwarf_info_buffer; + bfd_size_type alt_dwarf_info_size; + /* A pointer to the memory block allocated for info_ptr. Neither info_ptr nor sec_info_ptr are guaranteed to stay pointing to the beginning of the malloc block. This is used only to free the @@ -290,6 +299,7 @@ const struct dwarf_debug_section dwarf_debug_sections[] = { ".debug_aranges", ".zdebug_aranges" }, { ".debug_frame", ".zdebug_frame" }, { ".debug_info", ".zdebug_info" }, + { ".debug_info", ".zdebug_info" }, { ".debug_line", ".zdebug_line" }, { ".debug_loc", ".zdebug_loc" }, { ".debug_macinfo", ".zdebug_macinfo" }, @@ -300,6 +310,7 @@ const struct dwarf_debug_section dwarf_debug_sections[] = { ".debug_static_func", ".zdebug_static_func" }, { ".debug_static_vars", ".zdebug_static_vars" }, { ".debug_str", ".zdebug_str", }, + { ".debug_str", ".zdebug_str", }, { ".debug_types", ".zdebug_types" }, /* GNU DWARF 1 extensions */ { ".debug_sfnames", ".zdebug_sfnames" }, @@ -312,12 +323,15 @@ const struct dwarf_debug_section dwarf_debug_sections[] = { NULL, NULL }, }; +/* NB/ Numbers in this enum must match up with indicies + into the dwarf_debug_sections[] array above. */ enum dwarf_debug_section_enum { debug_abbrev = 0, debug_aranges, debug_frame, debug_info, + debug_info_alt, debug_line, debug_loc, debug_macinfo, @@ -328,6 +342,7 @@ enum dwarf_debug_section_enum debug_static_func, debug_static_vars, debug_str, + debug_str_alt, debug_types, debug_sfnames, debug_srcinfo, @@ -484,8 +499,8 @@ read_section (bfd * abfd, asection *msec; const char *section_name = sec->uncompressed_name; - /* read_section is a noop if the section has already been read. */ - if (!*section_buffer) + /* The section may have already been read. */ + if (*section_buffer == NULL) { msec = bfd_get_section_by_name (abfd, section_name); if (! msec) @@ -626,6 +641,104 @@ read_indirect_string (struct comp_unit * unit, return str; } +/* Like read_indirect_string but uses a .debug_str located in + an alternate filepointed to by the .gnu_debuglink section. + Used to impement DW_FORM_GNU_strp_alt. */ + +static char * +read_alt_indirect_string (struct comp_unit * unit, + bfd_byte * buf, + unsigned int * bytes_read_ptr) +{ + bfd_uint64_t offset; + struct dwarf2_debug *stash = unit->stash; + char *str; + + if (unit->offset_size == 4) + offset = read_4_bytes (unit->abfd, buf); + else + offset = read_8_bytes (unit->abfd, buf); + + *bytes_read_ptr = unit->offset_size; + + if (stash->alt_bfd_ptr == NULL) + { + bfd * debug_bfd; + char * debug_filename = bfd_follow_gnu_debugaltlink (unit->abfd, DEBUGDIR); + + if (debug_filename == NULL) + return NULL; + + if ((debug_bfd = bfd_openr (debug_filename, NULL)) == NULL + || ! bfd_check_format (debug_bfd, bfd_object)) + { + if (debug_bfd) + bfd_close (debug_bfd); + + /* FIXME: Should we report our failure to follow the debuglink ? */ + free (debug_filename); + return NULL; + } + stash->alt_bfd_ptr = debug_bfd; + } + + if (! read_section (unit->stash->alt_bfd_ptr, + stash->debug_sections + debug_str_alt, + NULL, /* FIXME: Do we need to load alternate symbols ? */ + offset, + &stash->alt_dwarf_str_buffer, + &stash->alt_dwarf_str_size)) + return NULL; + + str = (char *) stash->alt_dwarf_str_buffer + offset; + if (*str == '\0') + return NULL; + + return str; +} + +/* Resolve an alternate reference from UNIT at OFFSET. + Returns a pointer into the loaded alternate CU upon success + or NULL upon failure. */ + +static bfd_byte * +read_alt_indirect_ref (struct comp_unit * unit, + bfd_uint64_t offset) +{ + struct dwarf2_debug *stash = unit->stash; + + if (stash->alt_bfd_ptr == NULL) + { + bfd * debug_bfd; + char * debug_filename = bfd_follow_gnu_debugaltlink (unit->abfd, DEBUGDIR); + + if (debug_filename == NULL) + return FALSE; + + if ((debug_bfd = bfd_openr (debug_filename, NULL)) == NULL + || ! bfd_check_format (debug_bfd, bfd_object)) + { + if (debug_bfd) + bfd_close (debug_bfd); + + /* FIXME: Should we report our failure to follow the debuglink ? */ + free (debug_filename); + return NULL; + } + stash->alt_bfd_ptr = debug_bfd; + } + + if (! read_section (unit->stash->alt_bfd_ptr, + stash->debug_sections + debug_info_alt, + NULL, /* FIXME: Do we need to load alternate symbols ? */ + offset, + &stash->alt_dwarf_info_buffer, + &stash->alt_dwarf_info_size)) + return NULL; + + return stash->alt_dwarf_info_buffer + offset; +} + static bfd_uint64_t read_address (struct comp_unit *unit, bfd_byte *buf) { @@ -829,6 +942,7 @@ read_attribute_value (struct attribute *attr, attr->u.val = read_address (unit, info_ptr); info_ptr += unit->addr_size; break; + case DW_FORM_GNU_ref_alt: case DW_FORM_sec_offset: if (unit->offset_size == 4) attr->u.val = read_4_bytes (unit->abfd, info_ptr); @@ -878,6 +992,10 @@ read_attribute_value (struct attribute *attr, attr->u.str = read_indirect_string (unit, info_ptr, &bytes_read); info_ptr += bytes_read; break; + case DW_FORM_GNU_strp_alt: + attr->u.str = read_alt_indirect_string (unit, info_ptr, &bytes_read); + info_ptr += bytes_read; + break; case DW_FORM_exprloc: case DW_FORM_block: amt = sizeof (struct dwarf_block); @@ -950,7 +1068,7 @@ read_attribute_value (struct attribute *attr, info_ptr = read_attribute_value (attr, form, unit, info_ptr); break; default: - (*_bfd_error_handler) (_("Dwarf Error: Invalid or unhandled FORM value: %u."), + (*_bfd_error_handler) (_("Dwarf Error: Invalid or unhandled FORM value: %#x."), form); bfd_set_error (bfd_error_bad_value); return NULL; @@ -1996,7 +2114,7 @@ find_abstract_instance_name (struct comp_unit *unit, struct abbrev_info *abbrev; bfd_uint64_t die_ref = attr_ptr->u.val; struct attribute attr; - char *name = 0; + char *name = NULL; /* DW_FORM_ref_addr can reference an entry in a different CU. It is an offset from the .debug_info section, not the current CU. */ @@ -2009,8 +2127,20 @@ find_abstract_instance_name (struct comp_unit *unit, info_ptr = unit->sec_info_ptr + die_ref; } + else if (attr_ptr->form == DW_FORM_GNU_ref_alt) + { + info_ptr = read_alt_indirect_ref (unit, die_ref); + if (info_ptr == NULL) + { + (*_bfd_error_handler) + (_("Dwarf Error: Unable to read alt ref %u."), die_ref); + bfd_set_error (bfd_error_bad_value); + return name; + } + } else info_ptr = unit->info_ptr_unit + die_ref; + abbrev_number = read_unsigned_leb128 (abfd, info_ptr, &bytes_read); info_ptr += bytes_read; @@ -3694,4 +3824,10 @@ _bfd_dwarf2_cleanup_debug_info (bfd *abfd, void **pinfo) free (stash->info_ptr_memory); if (stash->close_on_cleanup) bfd_close (stash->bfd_ptr); + if (stash->alt_dwarf_str_buffer) + free (stash->alt_dwarf_str_buffer); + if (stash->alt_dwarf_info_buffer) + free (stash->alt_dwarf_info_buffer); + if (stash->alt_bfd_ptr) + bfd_close (stash->alt_bfd_ptr); } diff --git a/bfd/opncls.c b/bfd/opncls.c index 3879a65..cd9c826 100644 --- a/bfd/opncls.c +++ b/bfd/opncls.c @@ -1048,10 +1048,11 @@ bfd_release (bfd *abfd, void *block) This facilitates "optional" provision of debugging information, without having to provide two complete copies of every binary object (with and - without debug symbols). -*/ + without debug symbols). */ + +#define GNU_DEBUGLINK ".gnu_debuglink" +#define GNU_DEBUGALTLINK ".gnu_debugaltlink" -#define GNU_DEBUGLINK ".gnu_debuglink" /* FUNCTION bfd_calc_gnu_debuglink_crc32 @@ -1189,6 +1190,54 @@ bfd_get_debug_link_info (bfd *abfd, unsigned long *crc32_out) } /* +FUNCTION + bfd_get_alt_debug_link_info + +SYNOPSIS + char *bfd_get_alt_debug_link_info (bfd *abfd, unsigned long *crc32_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_out}. The + returned filename is allocated with @code{malloc}; freeing it + is the responsibility of the caller. +*/ + +char * +bfd_get_alt_debug_link_info (bfd * abfd, unsigned long * buildid_out) +{ + asection *sect; + bfd_byte *contents; + int buildid_offset; + char *name; + + BFD_ASSERT (abfd); + 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, aligned up to 4 bytes. */ + name = (char *) contents; + buildid_offset = strlen (name) + 1; + buildid_offset = (buildid_offset + 3) & ~3; + + * buildid_out = bfd_get_32 (abfd, contents + buildid_offset); + + return name; +} + +/* INTERNAL_FUNCTION separate_debug_file_exists @@ -1223,6 +1272,37 @@ separate_debug_file_exists (const char *name, const unsigned long crc) return crc == file_crc; } +/* +INTERNAL_FUNCTION + separate_alt_debug_file_exists + +SYNOPSIS + bfd_boolean separate_alt_debug_file_exists + (char *name, unsigned long crc32); + +DESCRIPTION + Checks to see if @var{name} is a file and if its BuildID + matches @var{buildid}. +*/ + +static bfd_boolean +separate_alt_debug_file_exists (const char *name, + const unsigned long buildid ATTRIBUTE_UNUSED) +{ + FILE *f; + + BFD_ASSERT (name); + + f = real_fopen (name, FOPEN_RB); + if (f == NULL) + return FALSE; + + /* FIXME: Add code to check buildid. */ + + fclose (f); + + return TRUE; +} /* INTERNAL_FUNCTION @@ -1232,16 +1312,24 @@ SYNOPSIS char *find_separate_debug_file (bfd *abfd); DESCRIPTION - Searches @var{abfd} for a reference to separate debugging - information, scans various locations in the filesystem, including - the file tree rooted at @var{debug_file_directory}, and returns a - filename of such debugging information if the file is found and has - matching CRC32. Returns NULL if no reference to debugging file - exists, or file cannot be found. + Searches @var{abfd} for a section called @var{section_name} which + is expected to contain a reference to a file containing separate + debugging information. The function scans various locations in + the filesystem, including the file tree rooted at + @var{debug_file_directory}, and returns the first matching + filename that it finds. If @var{check_crc} is TRUE then the + contents of the file must also match the CRC value contained in + @var{section_name}. Returns NULL if no valid file could be found. */ +typedef char * (* get_func_type) (bfd *, unsigned long *); +typedef bfd_boolean (* check_func_type) (const char *, const unsigned long); + static char * -find_separate_debug_file (bfd *abfd, const char *debug_file_directory) +find_separate_debug_file (bfd * abfd, + const char * debug_file_directory, + get_func_type get_func, + check_func_type check_func) { char *base; char *dir; @@ -1262,7 +1350,8 @@ find_separate_debug_file (bfd *abfd, const char *debug_file_directory) return NULL; } - base = bfd_get_debug_link_info (abfd, & crc32); + base = get_func (abfd, & crc32); + if (base == NULL) return NULL; @@ -1301,37 +1390,22 @@ find_separate_debug_file (bfd *abfd, const char *debug_file_directory) + strlen (base) + 1); if (debugfile == NULL) - { - free (base); - free (dir); - free (canon_dir); - return NULL; - } + goto found; /* Actually this returns NULL. */ /* First try in the same directory as the original file: */ strcpy (debugfile, dir); strcat (debugfile, base); - if (separate_debug_file_exists (debugfile, crc32)) - { - free (base); - free (dir); - free (canon_dir); - return debugfile; - } + if (check_func (debugfile, crc32)) + goto found; /* Then try in a subdirectory called .debug. */ strcpy (debugfile, dir); strcat (debugfile, ".debug/"); strcat (debugfile, base); - if (separate_debug_file_exists (debugfile, crc32)) - { - free (base); - free (dir); - free (canon_dir); - return debugfile; - } + if (check_func (debugfile, crc32)) + goto found; /* Then try in the global debugfile directory. */ strcpy (debugfile, debug_file_directory); @@ -1343,19 +1417,18 @@ find_separate_debug_file (bfd *abfd, const char *debug_file_directory) strcat (debugfile, canon_dir); strcat (debugfile, base); - if (separate_debug_file_exists (debugfile, crc32)) - { - free (base); - free (dir); - free (canon_dir); - return debugfile; - } + if (check_func (debugfile, crc32)) + goto found; + /* Failed to find the file. */ free (debugfile); + debugfile = NULL; + + found: free (base); free (dir); free (canon_dir); - return NULL; + return debugfile; } @@ -1388,7 +1461,43 @@ RETURNS char * bfd_follow_gnu_debuglink (bfd *abfd, const char *dir) { - return find_separate_debug_file (abfd, dir); + return find_separate_debug_file (abfd, dir, + bfd_get_debug_link_info, + separate_debug_file_exists); +} + +/* +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, it will search a default path configured into + libbfd at build time. [FIXME: This feature is not currently + implemented]. + +RETURNS + <> 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, + bfd_get_alt_debug_link_info, + separate_alt_debug_file_exists); } /* -- 2.7.4