From c4dcb155c446cee135101d72172b47e3fc99caf9 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Sun, 11 Jun 2017 23:16:01 +0200 Subject: [PATCH] Introduce "set debug separate-debug-file" I helped someone figure out why their separate debug info (debug link-based) was not found by gdb. It turns out that the debug file was not named properly. It made me realize that it is quite difficult to diagnose this kind of problems. This patch adds some debug output to show where GDB looks for those files, so that it should be (more) obvious to find what's wrong. Here's an example of the result, first with an example of unsuccessful lookup, and then a successful one. (gdb) set debug separate-debug-file on (gdb) file /usr/bin/gnome-calculator Reading symbols from /usr/bin/gnome-calculator... Looking for separate debug info (build-id) for /usr/bin/gnome-calculator Trying /usr/local/lib/debug/.build-id/0d/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug Looking for separate debug info (debug link) for /usr/bin/gnome-calculator Trying /usr/bin/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug Trying /usr/bin/.debug/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug Trying /usr/local/lib/debug//usr/bin/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug (no debugging symbols found)...done. (gdb) set debug-file-directory /usr/lib/debug (gdb) file /usr/bin/gnome-calculator Reading symbols from /usr/bin/gnome-calculator... Looking for separate debug info by build-id for /usr/bin/gnome-calculator Trying /usr/lib/debug/.build-id/0d/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug Reading symbols from /usr/lib/debug/.build-id/0d/5c5e8c86dbe4f4f95f7a13de04f91d377f3c6a.debug...done. done. Note: here, the debug link happens to be named like the build-id, but it doesn't have to be this way. It puzzled me for a minute. gdb/ChangeLog: * NEWS (Changes since GDB 8.0): Announce {set,show} debug separate-debug-file commands. * symfile.h (separate_debug_file_debug): New global. * symfile.c (separate_debug_file_debug): New global. (separate_debug_file_exists, find_separate_debug_file): Add debug output. (_initialize_symfile): Add "set debug separate-debug-file" command. * build-id.c (build_id_to_debug_bfd, find_separate_debug_file_by_buildid): Add debug output. gdb/doc/ChangeLog: * gdb.texinfo (Optional Messages about Internal Happenings): Document {set,show} debug separate-debug-file commands. --- gdb/ChangeLog | 13 +++++++++++++ gdb/NEWS | 6 ++++++ gdb/build-id.c | 7 +++++++ gdb/doc/ChangeLog | 5 +++++ gdb/doc/gdb.texinfo | 6 ++++++ gdb/symfile.c | 18 ++++++++++++++++++ gdb/symfile.h | 4 ++++ 7 files changed, 59 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c48fb92e9e..38a40e1302 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2017-06-11 Simon Marchi + + * NEWS (Changes since GDB 8.0): Announce {set,show} debug + separate-debug-file commands. + * symfile.h (separate_debug_file_debug): New global. + * symfile.c (separate_debug_file_debug): New global. + (separate_debug_file_exists, find_separate_debug_file): Add + debug output. + (_initialize_symfile): Add "set debug separate-debug-file" + command. + * build-id.c (build_id_to_debug_bfd, + find_separate_debug_file_by_buildid): Add debug output. + 2017-06-10 Simon Marchi * gdbarch.sh (displaced_step_free_closure): Remove. diff --git a/gdb/NEWS b/gdb/NEWS index 8dab5d3d8f..7c8a8f63de 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -17,6 +17,12 @@ QStartupWithShell Indicates whether the inferior must be started with a shell or not. +* New commands + +set debug separate-debug-file +show debug separate-debug-file + Control the display of debug output about separate debug file search. + *** Changes in GDB 8.0 * GDB now supports access to the PKU register on GNU/Linux. The register is diff --git a/gdb/build-id.c b/gdb/build-id.c index 0f63223877..4b2b63ecb4 100644 --- a/gdb/build-id.c +++ b/gdb/build-id.c @@ -112,6 +112,9 @@ build_id_to_debug_bfd (size_t build_id_len, const bfd_byte *build_id) s += sprintf (s, "%02x", (unsigned) *data++); strcpy (s, ".debug"); + if (separate_debug_file_debug) + printf_unfiltered (_(" Trying %s\n"), link); + /* lrealpath() is expensive even for the usually non-existent files. */ if (access (link, F_OK) == 0) filename = lrealpath (link); @@ -147,6 +150,10 @@ find_separate_debug_file_by_buildid (struct objfile *objfile) build_id = build_id_bfd_get (objfile->obfd); if (build_id != NULL) { + if (separate_debug_file_debug) + printf_unfiltered (_("\nLooking for separate debug info (build-id) for " + "%s\n"), objfile_name (objfile)); + gdb_bfd_ref_ptr abfd (build_id_to_debug_bfd (build_id->size, build_id->data)); /* Prevent looping on a stripped .debug file. */ diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 868cde90dd..aa4a9ce2f0 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,8 @@ +2017-06-11 Simon Marchi + + * gdb.texinfo (Optional Messages about Internal Happenings): + Document {set,show} debug separate-debug-file commands. + 2017-06-07 Sergio Durigan Junior * gdb.texinfo (Starting) : Add @anchor. diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 8d7a1c956c..c167a8654f 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -23984,6 +23984,12 @@ the serial line to the remote machine. The info is printed on the @value{GDBN} standard output stream. The default is off. @item show debug remote Displays the state of display of remote packets. + +@item set debug separate-debug-file +Turns on or off display of debug output about separate debug file search. +@item show debug separate-debug-file +Displays the state of separate debug file search debug output. + @item set debug serial Turns on or off display of @value{GDBN} serial debugging info. The default is off. diff --git a/gdb/symfile.c b/gdb/symfile.c index 846aabec48..f936cf3fa5 100644 --- a/gdb/symfile.c +++ b/gdb/symfile.c @@ -1333,6 +1333,10 @@ symbol_file_clear (int from_tty) printf_unfiltered (_("No symbol file now.\n")); } +/* See symfile.h. */ + +int separate_debug_file_debug = 0; + static int separate_debug_file_exists (const char *name, unsigned long crc, struct objfile *parent_objfile) @@ -1351,6 +1355,9 @@ separate_debug_file_exists (const char *name, unsigned long crc, if (filename_cmp (name, objfile_name (parent_objfile)) == 0) return 0; + if (separate_debug_file_debug) + printf_unfiltered (_(" Trying %s\n"), name); + gdb_bfd_ref_ptr abfd (gdb_bfd_open (name, gnutarget, -1)); if (abfd == NULL) @@ -1444,6 +1451,10 @@ find_separate_debug_file (const char *dir, struct cleanup *back_to; int ix; + if (separate_debug_file_debug) + printf_unfiltered (_("\nLooking for separate debug info (debug link) for " + "%s\n"), objfile_name (objfile)); + /* Set I to std::max (strlen (canon_dir), strlen (dir)). */ i = strlen (dir); if (canon_dir != NULL && strlen (canon_dir) > i) @@ -3975,4 +3986,11 @@ full == print messages for the executable,\n\ NULL, NULL, &setprintlist, &showprintlist); + + add_setshow_boolean_cmd ("separate-debug-file", no_class, + &separate_debug_file_debug, _("\ +Set printing of separate debug info file search debug."), _("\ +Show printing of separate debug info file search debug."), _("\ +When on, GDB prints the searched locations while looking for separate debug \ +info files."), NULL, NULL, &setdebuglist, &showdebuglist); } diff --git a/gdb/symfile.h b/gdb/symfile.h index ab536e8083..bb47fdf7cf 100644 --- a/gdb/symfile.h +++ b/gdb/symfile.h @@ -646,4 +646,8 @@ extern void elfmdebug_build_psymtabs (struct objfile *, extern gdb_bfd_ref_ptr find_separate_debug_file_in_section (struct objfile *); +/* True if we are printing debug output about separate debug info files. */ + +extern int separate_debug_file_debug; + #endif /* !defined(SYMFILE_H) */ -- 2.34.1