From 8b33bfe600d6b3f7bebf89eff06798eac78b7a02 Mon Sep 17 00:00:00 2001 From: Jim Blandy Date: Mon, 23 Dec 2002 09:22:59 +0000 Subject: Add support for executables whose debug info has been separated out into a separate file, leaving only a link behind. * objfiles.h (struct objfile): New fields: separate_debug_objfile and separate_debug_objfile_backlink. (put_objfile_before): New declaration. * symfile.c: #include "filenames.h". (symbol_file_add_with_addrs_or_offsets): If this objfile has its debug info in a separate file, read that, too. Save the addrs argument, so we can use it again to read the separated debug info; syms_from_objfile modifies the table we pass it. (reread_symbols): After re-reading an objfile, call reread_separate_symbols to refresh its separate debug info objfile, if it has one. (reread_separate_symbols, find_separate_debug_file, get_debug_link_info, separate_debug_file_exists): New functions. (debug_file_directory): New global var. (_initialize_symfile): Initialize debug_file_directory, and provide the new `set debug-file-directory' command to let the user change it. * objfiles.c (free_objfile): If this objfile has its debug info in a separate objfile, free that one too. If this is itself a separate debug info objfile, clear our parent's backlink. (put_objfile_before): New function. * utils.c (gnu_debuglink_crc32): New function. * defs.h (gnu_debuglink_crc32): New declaration. * Makefile.in (symfile.o): Note dependency on "filenames.h". * configure.in: Handle --with-separate-debug-dir config option. * acinclude.m4 (AC_DEFINE_DIR): New macro. * acconfig.h (DEBUGDIR): New macro. * configure, aclocal.m4, config.in: Regenerated. --- gdb/symfile.c | 260 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 260 insertions(+) diff --git a/gdb/symfile.c b/gdb/symfile.c index d7817918d84..b6529f7994d 100644 --- a/gdb/symfile.c +++ b/gdb/symfile.c @@ -38,6 +38,7 @@ #include "complaints.h" #include "demangle.h" #include "inferior.h" /* for write_pc */ +#include "filenames.h" /* for DOSish file names */ #include "gdb-stabs.h" #include "gdb_obstack.h" #include "completer.h" @@ -105,6 +106,8 @@ static void add_symbol_file_command (char *, int); static void add_shared_symbol_files_command (char *, int); +static void reread_separate_symbols (struct objfile *objfile); + static void cashier_psymtab (struct partial_symtab *); bfd *symfile_bfd_open (char *); @@ -149,6 +152,8 @@ static void set_ext_lang_command (char *args, int from_tty); static void info_ext_lang_command (char *args, int from_tty); +static char *find_separate_debug_file (struct objfile *objfile); + static void init_filename_language_table (void); void _initialize_symfile (void); @@ -888,7 +893,12 @@ symbol_file_add_with_addrs_or_offsets (char *name, int from_tty, { struct objfile *objfile; struct partial_symtab *psymtab; + char *debugfile; bfd *abfd; + struct section_addr_info orig_addrs; + + if (addrs) + orig_addrs = *addrs; /* Open a bfd for the file, and give user a chance to burp if we'd be interactively wiping out any existing symbols. */ @@ -963,6 +973,37 @@ symbol_file_add_with_addrs_or_offsets (char *name, int from_tty, } } + debugfile = find_separate_debug_file (objfile); + if (debugfile) + { + if (from_tty || info_verbose) + { + printf_filtered ("loading separate debug info from '%s'", + debugfile); + wrap_here (""); + gdb_flush (gdb_stdout); + } + + if (addrs != NULL) + { + objfile->separate_debug_objfile + = symbol_file_add (debugfile, from_tty, &orig_addrs, 0, flags); + } + else + { + objfile->separate_debug_objfile + = symbol_file_add (debugfile, from_tty, NULL, 0, flags); + } + objfile->separate_debug_objfile->separate_debug_objfile_backlink + = objfile; + + /* Put the separate debug object before the normal one, this is so that + usage of the ALL_OBJFILES_SAFE macro will stay safe. */ + put_objfile_before (objfile->separate_debug_objfile, objfile); + + xfree (debugfile); + } + if (from_tty || info_verbose) { if (post_add_symbol_hook) @@ -1058,6 +1099,141 @@ symbol_file_clear (int from_tty) #endif } +static char * +get_debug_link_info (struct objfile *objfile, unsigned long *crc32_out) +{ + asection *sect; + bfd_size_type debuglink_size; + unsigned long crc32; + char *contents; + int crc_offset; + unsigned char *p; + + sect = bfd_get_section_by_name (objfile->obfd, ".gnu_debuglink"); + + if (sect == NULL) + return NULL; + + debuglink_size = bfd_section_size (objfile->obfd, sect); + + contents = xmalloc (debuglink_size); + bfd_get_section_contents (objfile->obfd, sect, contents, + (file_ptr)0, (bfd_size_type)debuglink_size); + + /* Crc value is stored after the filename, aligned up to 4 bytes. */ + crc_offset = strlen (contents) + 1; + crc_offset = (crc_offset + 3) & ~3; + + crc32 = bfd_get_32 (objfile->obfd, (bfd_byte *) (contents + crc_offset)); + + *crc32_out = crc32; + return contents; +} + +static int +separate_debug_file_exists (const char *name, unsigned long crc) +{ + unsigned long file_crc = 0; + int fd; + char buffer[8*1024]; + int count; + + fd = open (name, O_RDONLY | O_BINARY); + if (fd < 0) + return 0; + + while ((count = read (fd, buffer, sizeof (buffer))) > 0) + file_crc = gnu_debuglink_crc32 (file_crc, buffer, count); + + close (fd); + + return crc == file_crc; +} + +static char *debug_file_directory = NULL; + +#if ! defined (DEBUG_SUBDIRECTORY) +#define DEBUG_SUBDIRECTORY ".debug" +#endif + +static char * +find_separate_debug_file (struct objfile *objfile) +{ + asection *sect; + char *basename; + char *dir; + char *debugfile; + char *name_copy; + bfd_size_type debuglink_size; + unsigned long crc32; + int i; + + basename = get_debug_link_info (objfile, &crc32); + + if (basename == NULL) + return NULL; + + dir = xstrdup (objfile->name); + + /* Strip off filename part */ + for (i = strlen(dir) - 1; i >= 0; i--) + { + if (IS_DIR_SEPARATOR (dir[i])) + break; + } + dir[i+1] = '\0'; + + debugfile = alloca (strlen (debug_file_directory) + 1 + + strlen (dir) + + strlen (DEBUG_SUBDIRECTORY) + + strlen ("/") + + strlen (basename) + + 1); + + /* First try in the same directory as the original file. */ + strcpy (debugfile, dir); + strcat (debugfile, basename); + + if (separate_debug_file_exists (debugfile, crc32)) + { + xfree (basename); + xfree (dir); + return xstrdup (debugfile); + } + + /* Then try in the subdirectory named DEBUG_SUBDIRECTORY. */ + strcpy (debugfile, dir); + strcat (debugfile, DEBUG_SUBDIRECTORY); + strcat (debugfile, "/"); + strcat (debugfile, basename); + + if (separate_debug_file_exists (debugfile, crc32)) + { + xfree (basename); + xfree (dir); + return xstrdup (debugfile); + } + + /* Then try in the global debugfile directory. */ + strcpy (debugfile, debug_file_directory); + strcat (debugfile, "/"); + strcat (debugfile, dir); + strcat (debugfile, "/"); + strcat (debugfile, basename); + + if (separate_debug_file_exists (debugfile, crc32)) + { + xfree (basename); + xfree (dir); + return xstrdup (debugfile); + } + + xfree (basename); + xfree (dir); + return NULL; +} + + /* This is the symbol-file command. Read the file, analyze its symbols, and add a struct symtab to a symtab list. The syntax of the command is rather bizarre--(1) buildargv implements various @@ -1903,6 +2079,8 @@ reread_symbols (void) needs to keep track of (such as _sigtramp, or whatever). */ TARGET_SYMFILE_POSTREAD (objfile); + + reread_separate_symbols (objfile); } } } @@ -1910,6 +2088,73 @@ reread_symbols (void) if (reread_one) clear_symtab_users (); } + + +/* Handle separate debug info for OBJFILE, which has just been + re-read: + - If we had separate debug info before, but now we don't, get rid + of the separated objfile. + - If we didn't have separated debug info before, but now we do, + read in the new separated debug info file. + - If the debug link points to a different file, toss the old one + and read the new one. + This function does *not* handle the case where objfile is still + using the same separate debug info file, but that file's timestamp + has changed. That case should be handled by the loop in + reread_symbols already. */ +static void +reread_separate_symbols (struct objfile *objfile) +{ + char *debug_file; + unsigned long crc32; + + /* Does the updated objfile's debug info live in a + separate file? */ + debug_file = find_separate_debug_file (objfile); + + if (objfile->separate_debug_objfile) + { + /* There are two cases where we need to get rid of + the old separated debug info objfile: + - if the new primary objfile doesn't have + separated debug info, or + - if the new primary objfile has separate debug + info, but it's under a different filename. + + If the old and new objfiles both have separate + debug info, under the same filename, then we're + okay --- if the separated file's contents have + changed, we will have caught that when we + visited it in this function's outermost + loop. */ + if (! debug_file + || strcmp (debug_file, objfile->separate_debug_objfile->name) != 0) + free_objfile (objfile->separate_debug_objfile); + } + + /* If the new objfile has separate debug info, and we + haven't loaded it already, do so now. */ + if (debug_file + && ! objfile->separate_debug_objfile) + { + /* Use the same section offset table as objfile itself. + Preserve the flags from objfile that make sense. */ + objfile->separate_debug_objfile + = (symbol_file_add_with_addrs_or_offsets + (debug_file, + info_verbose, /* from_tty: Don't override the default. */ + 0, /* No addr table. */ + objfile->section_offsets, objfile->num_sections, + 0, /* Not mainline. See comments about this above. */ + objfile->flags & (OBJF_MAPPED | OBJF_REORDERED + | OBJF_SHARED | OBJF_READNOW + | OBJF_USERLOADED))); + objfile->separate_debug_objfile->separate_debug_objfile_backlink + = objfile; + } +} + + @@ -3418,4 +3663,19 @@ Usage: set extension-language .foo bar", "cache.\n", &setlist), &showlist); + + debug_file_directory = xstrdup (DEBUGDIR); + c = (add_set_cmd + ("debug-file-directory", class_support, var_string, + (char *) &debug_file_directory, + "Set the directory where separate debug symbols are searched for.\n" + "Separate debug symbols are first searched for in the same\n" + "directory as the binary, then in the `" DEBUG_SUBDIRECTORY + "' subdirectory,\n" + "and lastly at the path of the directory of the binary with\n" + "the global debug-file directory prepended\n", + &setlist)); + add_show_from_set (c, &showlist); + set_cmd_completer (c, filename_completer); + } -- cgit v1.2.1