From 566f5e3b385a99c09b5babc9f90dae93e052d52c Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Mon, 13 Apr 2015 16:56:23 +0100 Subject: [PATCH] gdb: Add debug tracing for bfd cache activity. This patch adds a new debug flag bfd-cache, which when set to non-zero produces debugging log messages relating to gdb's bfd cache. gdb/ChangeLog: * gdb_bfd.c (debug_bfd_cache): New variable. (show_bfd_cache_debug): New function. (gdb_bfd_open): Add debug logging. (gdb_bfd_ref): Likewise. (gdb_bfd_unref): Likewise. (_initialize_gdb_bfd): Add new set/show command. * NEWS: Mention new command. gdb/doc/ChangeLog: * gdb.texinfo (File Caching): Document "set/show debug bfd-cache". --- gdb/ChangeLog | 10 +++++++++ gdb/NEWS | 4 ++++ gdb/doc/ChangeLog | 4 ++++ gdb/doc/gdb.texinfo | 10 +++++++++ gdb/gdb_bfd.c | 51 ++++++++++++++++++++++++++++++++++++++++++++- 5 files changed, 78 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b2860488e22..51bae8702e8 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2015-08-18 Andrew Burgess + + * gdb_bfd.c (debug_bfd_cache): New variable. + (show_bfd_cache_debug): New function. + (gdb_bfd_open): Add debug logging. + (gdb_bfd_ref): Likewise. + (gdb_bfd_unref): Likewise. + (_initialize_gdb_bfd): Add new set/show command. + * NEWS: Mention new command. + 2015-08-18 Andrew Burgess * gdb_bfd.c (bfd_sharing): New variable. diff --git a/gdb/NEWS b/gdb/NEWS index 7a24e234429..2cedccd336b 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -24,6 +24,10 @@ maint set bfd-sharing maint show bfd-sharing Control the reuse of bfd objects. +set debug bfd-cache +show debug bfd-cache + Control display of debugging info regarding bfd caching. + * The "disassemble" command accepts a new modifier: /s. It prints mixed source+disassembly like /m with two differences: - disassembled instructions are now printed in program order, and diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 7716917d7d6..b3dbc5955c0 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,7 @@ +2015-08-18 Andrew Burgess + + * gdb.texinfo (File Caching): Document "set/show debug bfd-cache". + 2015-08-18 Andrew Burgess * gdb.texinfo (Maintenance Commands): Move documentation of "main diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index bd6b8e4a428..9322a526d10 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -18371,6 +18371,16 @@ already shared @code{bfd} objects to be unshared, but all future files that are opened will create a new @code{bfd} object. Similarly, re-enabling sharing does not cause multiple existing @code{bfd} objects to be collapsed into a single shared @code{bfd} object. + +@kindex set debug bfd-cache @var{level} +@kindex bfd caching +@item set debug bfd-cache @var{level} +Turns on debugging of the bfd cache, setting the level to @var{level}. + +@kindex show debug bfd-cache +@kindex bfd caching +@item show debug bfd-cache +Show the current debugging level of the bfd cache. @end table @node Separate Debug Files diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c index 847177524c2..eb53766fd7b 100644 --- a/gdb/gdb_bfd.c +++ b/gdb/gdb_bfd.c @@ -122,6 +122,16 @@ show_bfd_sharing (struct ui_file *file, int from_tty, fprintf_filtered (file, _("BFD sharing is %s.\n"), value); } +/* When non-zero debugging of the bfd caches is enabled. */ + +static unsigned int debug_bfd_cache; +static void +show_bfd_cache_debug (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, _("BFD cache debugging is %s.\n"), value); +} + /* The type of an object being looked up in gdb_bfd_cache. We use htab's capability of storing one kind of object (BFD in this case) and using a different sort of object for searching. */ @@ -407,6 +417,11 @@ gdb_bfd_open (const char *name, const char *target, int fd) abfd = htab_find_with_hash (gdb_bfd_cache, &search, hash); if (bfd_sharing && abfd != NULL) { + if (debug_bfd_cache) + fprintf_unfiltered (gdb_stdlog, + "Reusing cached bfd %s for %s\n", + host_address_to_string (abfd), + bfd_get_filename (abfd)); close (fd); gdb_bfd_ref (abfd); return abfd; @@ -416,6 +431,12 @@ gdb_bfd_open (const char *name, const char *target, int fd) if (abfd == NULL) return NULL; + if (debug_bfd_cache) + fprintf_unfiltered (gdb_stdlog, + "Creating new bfd %s for %s\n", + host_address_to_string (abfd), + bfd_get_filename (abfd)); + if (bfd_sharing) { slot = htab_find_slot_with_hash (gdb_bfd_cache, &search, hash, INSERT); @@ -484,6 +505,12 @@ gdb_bfd_ref (struct bfd *abfd) gdata = bfd_usrdata (abfd); + if (debug_bfd_cache) + fprintf_unfiltered (gdb_stdlog, + "Increase reference count on bfd %s (%s)\n", + host_address_to_string (abfd), + bfd_get_filename (abfd)); + if (gdata != NULL) { gdata->refc += 1; @@ -537,7 +564,20 @@ gdb_bfd_unref (struct bfd *abfd) gdata->refc -= 1; if (gdata->refc > 0) - return; + { + if (debug_bfd_cache) + fprintf_unfiltered (gdb_stdlog, + "Decrease reference count on bfd %s (%s)\n", + host_address_to_string (abfd), + bfd_get_filename (abfd)); + return; + } + + if (debug_bfd_cache) + fprintf_unfiltered (gdb_stdlog, + "Delete final reference count on bfd %s (%s)\n", + host_address_to_string (abfd), + bfd_get_filename (abfd)); archive_bfd = gdata->archive_bfd; search.filename = bfd_get_filename (abfd); @@ -968,4 +1008,13 @@ filename, file size, file modification time, and file inode."), &show_bfd_sharing, &maintenance_set_cmdlist, &maintenance_show_cmdlist); + + add_setshow_zuinteger_cmd ("bfd-cache", class_maintenance, + &debug_bfd_cache, _("\ +Set bfd cache debugging."), _("\ +Show bfd cache debugging."), _("\ +When non-zero, bfd cache specific debugging is enabled."), + NULL, + &show_bfd_cache_debug, + &setdebuglist, &showdebuglist); } -- 2.30.2