* main.c (gdb_datadir_provided): New static global.

	(get_init_files): If --data-directory is provided,
	and SYSTEM_GDBINIT lives in data-directory, look for it there.
	* NEWS: Mention it.

	doc/
	* gdb.texinfo (System-wide configuration): If the system-wide init
	file lives in the data-directory, and --data-directory is provided,
	look for it there.

5 files changed, 66 insertions, 4 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 1aeafec..0b79e91 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2012-11-16  Doug Evans  <dje@google.com>
+
+	* main.c (gdb_datadir_provided): New static global.
+	(get_init_files): If --data-directory is provided,
+	and SYSTEM_GDBINIT lives in data-directory, look for it there.
+	* NEWS: Mention it.
+
 2012-11-15  Pierre Muller  <muller@sourceware.org>
 
 	ARI fixes: move gdb_wait and gdb_stat headers to common subdirectory.
diff --git a/gdb/NEWS b/gdb/NEWS
index 9375218..5e3f54d 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,13 @@
 
 *** Changes since GDB 7.5
 
+* If the configured location of system.gdbinit file (as given by the
+  --with-system-gdbinit option at configure time) is in the
+  data-directory (as specified by --with-gdb-datadir at configure
+  time) or in one of its subdirectories, then GDB will look for the
+  system-wide init file in the directory specified by the
+  --data-directory command-line option.
+
 * New command line options:
 
 -nh   Disables auto-loading of ~/.gdbinit, but still executes all the
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index a774681..8fda5d5 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-16  Doug Evans  <dje@google.com>
+
+	* gdb.texinfo (System-wide configuration): If the system-wide init
+	file lives in the data-directory, and --data-directory is provided,
+	look for it there.
+
 2012-11-15  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.texinfo (Signaling): Fix typo.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 945a66b..80148f7 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -34765,6 +34765,17 @@ then @value{GDBN} will always look for @file{/usr/share/gdb/gdbinit},
 wherever @value{GDBN} is installed.
 @end itemize
 
+If the configured location of the system-wide init file (as given by the
+@option{--with-system-gdbinit} option at configure time) is in the
+data-directory (as specified by @option{--with-gdb-datadir} at configure
+time) or in one of its subdirectories, then @value{GDBN} will look for the
+system-wide init file in the directory specified by the
+@option{--data-directory} command-line option.
+Note that the system-wide init file is only read once, during @value{GDBN}
+initialization.  If the data-directory is changed after @value{GDBN} has
+started with the @code{set data-directory} command, the file will not be
+reread.
+
 @node Maintenance Commands
 @appendix Maintenance Commands
 @cindex maintenance commands
diff --git a/gdb/main.c b/gdb/main.c
index 923a7fe..57fe94f 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -60,6 +60,11 @@ char *gdb_sysroot = 0;
 /* GDB datadir, used to store data files.  */
 char *gdb_datadir = 0;
 
+/* Non-zero if GDB_DATADIR was provided on the command line.
+   This doesn't track whether data-directory is set later from the
+   command line, but we don't reread system.gdbinit when that happens.  */
+static int gdb_datadir_provided = 0;
+
 /* If gdb was configured with --with-python=/path,
    the possibly relocated path to python's lib directory.  */
 char *python_libdir = 0;
@@ -163,13 +168,38 @@ get_init_files (char **system_gdbinit,
   if (!initialized)
     {
       struct stat homebuf, cwdbuf, s;
-      char *homedir, *relocated_sysgdbinit;
+      char *homedir;
 
       if (SYSTEM_GDBINIT[0])
 	{
-	  relocated_sysgdbinit = relocate_path (gdb_program_name,
-						SYSTEM_GDBINIT,
-						SYSTEM_GDBINIT_RELOCATABLE);
+	  int datadir_len = strlen (GDB_DATADIR);
+	  int sys_gdbinit_len = strlen (SYSTEM_GDBINIT);
+	  char *relocated_sysgdbinit;
+
+	  /* If SYSTEM_GDBINIT lives in data-directory, and data-directory
+	     has been provided, search for SYSTEM_GDBINIT there.  */
+	  if (gdb_datadir_provided
+	      && datadir_len < sys_gdbinit_len
+	      && strncmp (SYSTEM_GDBINIT, GDB_DATADIR, datadir_len) == 0
+	      && strchr (SLASH_STRING, SYSTEM_GDBINIT[datadir_len]) != NULL)
+	    {
+	      /* Append the part of SYSTEM_GDBINIT that follows GDB_DATADIR
+		 to gdb_datadir.  */
+	      char *tmp_sys_gdbinit = xstrdup (SYSTEM_GDBINIT + datadir_len);
+	      char *p;
+
+	      for (p = tmp_sys_gdbinit; strchr (SLASH_STRING, *p); ++p)
+		continue;
+	      relocated_sysgdbinit = concat (gdb_datadir, SLASH_STRING, p,
+					     NULL);
+	      xfree (tmp_sys_gdbinit);
+	    }
+	  else
+	    {
+	      relocated_sysgdbinit = relocate_path (gdb_program_name,
+						    SYSTEM_GDBINIT,
+						    SYSTEM_GDBINIT_RELOCATABLE);
+	    }
 	  if (relocated_sysgdbinit && stat (relocated_sysgdbinit, &s) == 0)
 	    sysgdbinit = relocated_sysgdbinit;
 	  else
@@ -591,6 +621,7 @@ captured_main (void *data)
 	  case 'D':
 	    xfree (gdb_datadir);
 	    gdb_datadir = xstrdup (optarg);
+	    gdb_datadir_provided = 1;
 	    break;
 #ifdef GDBTK
 	  case 'z':