[patch#4 6/8] set debug auto-load
http://sourceware.org/ml/gdb-patches/2012-04/msg00089.html
http://sourceware.org/ml/gdb-cvs/2012-04/msg00115.html

### src/gdb/ChangeLog	2012/04/17 15:54:28	1.14114
### src/gdb/ChangeLog	2012/04/17 15:56:20	1.14115
## -1,5 +1,27 @@
 2012-04-17  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
+	New option "set debug auto-load".
+	* NEWS: New commands "set debug auto-load" and "show debug auto-load".
+	* auto-load.c (debug_auto_load, show_debug_auto_load: New.
+	(auto_load_safe_path_vec_update)
+	(filename_is_in_auto_load_safe_path_vec): Call fprintf_unfiltered
+	if DEBUG_AUTO_LOAD.
+	(file_is_auto_load_safe): New parameters debug_fmt and ....
+	Call fprintf_unfiltered if DEBUG_AUTO_LOAD.
+	(source_gdb_script_for_objfile): Extend the file_is_auto_load_safe
+	caller by explanatory string.
+	(_initialize_auto_load): Register "set debug auto-load".
+	* auto-load.h (file_is_auto_load_safe): New parameters debug_fmt
+	and ....
+	* linux-thread-db.c (try_thread_db_load_from_pdir_1)
+	(try_thread_db_load_from_dir): Extend the file_is_auto_load_safe caller
+	by explanatory string.
+	* main.c (captured_main): Likewise.
+	* python/py-auto-load.c (gdbpy_load_auto_script_for_objfile)
+	(source_section_scripts): Likewise.
+
+2012-04-17  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
 	New option "set auto-load safe-path".
 	* NEWS: New commands "set auto-load safe-path"
 	and "show auto-load safe-path".
Index: gdb-7.4.50.20120120/gdb/NEWS
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/NEWS	2012-04-18 00:49:33.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/NEWS	2012-04-18 00:50:15.018600282 +0200
@@ -72,6 +72,10 @@ show auto-load safe-path
   Set a list of directories from which it is safe to auto-load files.
   The delimiter (':' above) may differ according to the host platform.
 
+set debug auto-load on|off
+show debug auto-load
+  Control display of debugging info for auto-loading the files above.
+
 * New command line options
 
 --init-command=FILE, -ix          Like --command, -x but execute it
Index: gdb-7.4.50.20120120/gdb/auto-load.c
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/auto-load.c	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/auto-load.c	2012-04-18 00:50:04.801626235 +0200
@@ -43,6 +43,20 @@
 static void source_gdb_script_for_objfile (struct objfile *objfile, FILE *file,
 					   const char *filename);
 
+/* Value of the 'set debug auto-load' configuration variable.  */
+static int debug_auto_load = 0;
+
+/* "show" command for the debug_auto_load configuration variable.  */
+
+static void
+show_debug_auto_load (struct ui_file *file, int from_tty,
+		      struct cmd_list_element *c, const char *value)
+{
+  fprintf_filtered (file, _("Debugging output for files "
+			    "of 'set auto-load ...' is %s.\n"),
+		    value);
+}
+
 /* User-settable option to enable/disable auto-loading of GDB_AUTO_FILE_NAME
    scripts:
    set auto-load gdb-scripts on|off
@@ -112,6 +126,11 @@ auto_load_safe_path_vec_update (void)
   unsigned len;
   int ix;
 
+  if (debug_auto_load)
+    fprintf_unfiltered (gdb_stdlog,
+			_("auto-load: Updating directories of \"%s\".\n"),
+			auto_load_safe_path);
+
   free_char_ptr_vec (auto_load_safe_path_vec);
 
   auto_load_safe_path_vec = dirnames_to_char_ptr_vec (auto_load_safe_path);
@@ -126,14 +145,34 @@ auto_load_safe_path_vec_update (void)
       char *real_path = gdb_realpath (expanded);
 
       /* Ensure the current entry is at least tilde_expand-ed.  */
-      xfree (dir);
       VEC_replace (char_ptr, auto_load_safe_path_vec, ix, expanded);
 
+      if (debug_auto_load)
+	{
+	  if (strcmp (expanded, dir) == 0)
+	    fprintf_unfiltered (gdb_stdlog,
+				_("auto-load: Using directory \"%s\".\n"),
+				expanded);
+	  else
+	    fprintf_unfiltered (gdb_stdlog,
+				_("auto-load: Resolved directory \"%s\" "
+				  "as \"%s\".\n"),
+				dir, expanded);
+	}
+      xfree (dir);
+
       /* If gdb_realpath returns a different content, append it.  */
       if (strcmp (real_path, expanded) == 0)
 	xfree (real_path);
       else
-	VEC_safe_push (char_ptr, auto_load_safe_path_vec, real_path);
+	{
+	  VEC_safe_push (char_ptr, auto_load_safe_path_vec, real_path);
+
+	  if (debug_auto_load)
+	    fprintf_unfiltered (gdb_stdlog,
+				_("auto-load: And canonicalized as \"%s\".\n"),
+				real_path);
+	}
     }
 }
 
@@ -217,16 +256,30 @@ filename_is_in_auto_load_safe_path_vec (
   if (dir == NULL)
     {
       if (*filename_realp == NULL)
-	*filename_realp = gdb_realpath (filename);
+	{
+	  *filename_realp = gdb_realpath (filename);
+	  if (debug_auto_load && strcmp (*filename_realp, filename) != 0)
+	    fprintf_unfiltered (gdb_stdlog,
+				_("auto-load: Resolved "
+				  "file \"%s\" as \"%s\".\n"),
+				filename, *filename_realp);
+	}
 
-      for (ix = 0; VEC_iterate (char_ptr, auto_load_safe_path_vec, ix, dir);
-	   ++ix)
-	if (filename_is_in_dir (*filename_realp, dir))
-	  break;
+      if (strcmp (*filename_realp, filename) != 0)
+	for (ix = 0; VEC_iterate (char_ptr, auto_load_safe_path_vec, ix, dir);
+	     ++ix)
+	  if (filename_is_in_dir (*filename_realp, dir))
+	    break;
     }
 
   if (dir != NULL)
-    return 1;
+    {
+      if (debug_auto_load)
+	fprintf_unfiltered (gdb_stdlog, _("auto-load: File \"%s\" matches "
+					  "directory \"%s\".\n"),
+			    filename, dir);
+      return 1;
+    }
 
   return 0;
 }
@@ -240,11 +293,20 @@ filename_is_in_auto_load_safe_path_vec (
    directory.  */
 
 int
-file_is_auto_load_safe (const char *filename)
+file_is_auto_load_safe (const char *filename, const char *debug_fmt, ...)
 {
   char *filename_real = NULL;
   struct cleanup *back_to;
 
+  if (debug_auto_load)
+    {
+      va_list debug_args;
+
+      va_start (debug_args, debug_fmt);
+      vfprintf_unfiltered (gdb_stdlog, debug_fmt, debug_args);
+      va_end (debug_args);
+    }
+
   back_to = make_cleanup (free_current_contents, &filename_real);
 
   if (filename_is_in_auto_load_safe_path_vec (filename, &filename_real))
@@ -281,7 +343,10 @@ source_gdb_script_for_objfile (struct ob
   struct auto_load_pspace_info *pspace_info;
   volatile struct gdb_exception e;
 
-  is_safe = file_is_auto_load_safe (filename);
+  is_safe = file_is_auto_load_safe (filename, _("auto-load: Loading canned "
+						"sequences of commands script "
+						"\"%s\" for objfile \"%s\".\n"),
+				    filename, objfile->name);
 
   /* Add this script to the hash table too so "info auto-load gdb-scripts"
      can print it.  */
@@ -975,4 +1040,13 @@ See the commands 'set auto-load safe-pat
 access the current full list setting."),
 		 &cmdlist);
   set_cmd_completer (cmd, filename_completer);
+
+  add_setshow_boolean_cmd ("auto-load", class_maintenance,
+			   &debug_auto_load, _("\
+Set auto-load verifications debugging."), _("\
+Show auto-load verifications debugging."), _("\
+When non-zero, debugging output for files of 'set auto-load ...'\n\
+is displayed."),
+			    NULL, show_debug_auto_load,
+			    &setdebuglist, &showdebuglist);
 }
Index: gdb-7.4.50.20120120/gdb/auto-load.h
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/auto-load.h	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/auto-load.h	2012-04-18 00:50:04.801626235 +0200
@@ -55,6 +55,7 @@ extern struct cmd_list_element **auto_lo
 extern struct cmd_list_element **auto_load_show_cmdlist_get (void);
 extern struct cmd_list_element **auto_load_info_cmdlist_get (void);
 
-extern int file_is_auto_load_safe (const char *filename);
+extern int file_is_auto_load_safe (const char *filename,
+				   const char *debug_fmt, ...);
 
 #endif /* AUTO_LOAD_H */
Index: gdb-7.4.50.20120120/gdb/linux-thread-db.c
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/linux-thread-db.c	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/linux-thread-db.c	2012-04-18 00:50:04.801626235 +0200
@@ -869,7 +869,9 @@ try_thread_db_load_from_pdir_1 (struct o
   gdb_assert (cp != NULL);
   strcpy (cp + 1, LIBTHREAD_DB_SO);
 
-  if (!file_is_auto_load_safe (path))
+  if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
+				       "library \"%s\" from $pdir.\n"),
+			       path))
     result = 0;
   else
     result = try_thread_db_load (path);
@@ -939,7 +941,10 @@ try_thread_db_load_from_dir (const char
   path[dir_len] = '/';
   strcpy (path + dir_len + 1, LIBTHREAD_DB_SO);
 
-  if (!file_is_auto_load_safe (path))
+  if (!file_is_auto_load_safe (path, _("auto-load: Loading libthread-db "
+				       "library \"%s\" from explicit "
+				       "directory.\n"),
+			       path))
     result = 0;
   else
     result = try_thread_db_load (path);
Index: gdb-7.4.50.20120120/gdb/main.c
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/main.c	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/main.c	2012-04-18 00:50:04.801626235 +0200
@@ -1027,7 +1027,10 @@ captured_main (void *data)
       auto_load_local_gdbinit_pathname = gdb_realpath (local_gdbinit);
 
       if (!inhibit_gdbinit && auto_load_local_gdbinit
-	  && file_is_auto_load_safe (local_gdbinit))
+	  && file_is_auto_load_safe (local_gdbinit,
+				     _("auto-load: Loading .gdbinit "
+				       "file \"%s\".\n"),
+				     local_gdbinit))
 	{
 	  auto_load_local_gdbinit_loaded = 1;
 
Index: gdb-7.4.50.20120120/gdb/doc/gdb.texinfo
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/doc/gdb.texinfo	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/doc/gdb.texinfo	2012-04-18 00:50:04.809626215 +0200
@@ -20887,6 +20887,7 @@ These are @value{GDBN} control commands
 * libthread_db.so.1 file::             @samp{set/show/info auto-load libthread-db}
 * objfile-gdb.gdb file::               @samp{set/show/info auto-load gdb-script}
 * Auto-loading safe path::             @samp{set/show/info auto-load safe-path}
+* Auto-loading verbose mode::          @samp{set/show debug auto-load}
 @xref{Python Auto-loading}.
 @end menu
 
@@ -21085,6 +21086,45 @@ entries again.  @value{GDBN} already can
 own before starting the comparison so a canonical form of directories is
 recommended to be entered.
 
+@node Auto-loading verbose mode
+@subsection Displaying files tried for auto-load
+@cindex auto-loading verbose mode
+
+For better visibility of all the file locations where you can place scripts to
+be auto-loaded with inferior --- or to protect yourself against accidental
+execution of untrusted scripts --- @value{GDBN} provides a feature for printing
+all the files attempted to be loaded.  Both existing and non-existing files may
+be printed.
+
+For example the list of directories from which it is safe to auto-load files
+(@pxref{Auto-loading safe path}) applies also to canonicalized filenames which
+may not be too obvious while setting it up.
+
+@smallexample
+(gdb) set debug auto-load ues
+(gdb) file ~/src/t/true
+auto-load: Loading canned sequences of commands script "/tmp/true-gdb.gdb"
+           for objfile "/tmp/true".
+auto-load: Updating directories of "/usr:/opt".
+auto-load: Using directory "/usr".
+auto-load: Using directory "/opt".
+warning: File "/tmp/true-gdb.gdb" auto-loading has been declined
+         by your `auto-load safe-path' set to "/usr:/opt".
+@end smallexample
+
+@table @code
+@anchor{set debug auto-load}
+@kindex set debug auto-load
+@item set debug auto-load [on|off]
+Set whether to print the filenames attempted to be auto-loaded.
+
+@anchor{show debug auto-load}
+@kindex show debug auto-load
+@item show debug auto-load
+Show whether printing of the filenames attempted to be auto-loaded is turned
+on or off.
+@end table
+
 @node Messages/Warnings
 @section Optional Warnings and Messages
 
Index: gdb-7.4.50.20120120/gdb/python/py-auto-load.c
===================================================================
--- gdb-7.4.50.20120120.orig/gdb/python/py-auto-load.c	2012-04-18 00:49:21.000000000 +0200
+++ gdb-7.4.50.20120120/gdb/python/py-auto-load.c	2012-04-18 00:50:04.810626212 +0200
@@ -75,7 +75,10 @@ gdbpy_load_auto_script_for_objfile (stru
   int is_safe;
   struct auto_load_pspace_info *pspace_info;
 
-  is_safe = file_is_auto_load_safe (filename);
+  is_safe = file_is_auto_load_safe (filename,
+				    _("auto-load: Loading Python script \"%s\" "
+				      "by extension for objfile \"%s\".\n"),
+				    filename, objfile->name);
 
   /* Add this script to the hash table too so "info auto-load python-scripts"
      can print it.  */
@@ -153,7 +156,12 @@ source_section_scripts (struct objfile *
 	  make_cleanup_fclose (stream);
 	  make_cleanup (xfree, full_path);
 
-	  if (!file_is_auto_load_safe (full_path))
+	  if (!file_is_auto_load_safe (full_path,
+				       _("auto-load: Loading Python script "
+					 "\"%s\" from section \"%s\" of "
+					 "objfile \"%s\".\n"),
+				       full_path, GDBPY_AUTO_SECTION_NAME,
+				       objfile->name))
 	    opened = 0;
 	}
       else