Add support for --with-system-gdbinit

[Daniel Jacobowitz <drow@false.org>]

As described on gdb@ last month, this patch adds support for a
system-wide gdbinit file.  The path will be automatically relocated if
the GDB binary is moved, so it can be used for a system-wide directory
like /etc or a prefixed directory like /opt/vendor/share.

Eli, is the doc patch OK?

-- 
Daniel Jacobowitz
CodeSourcery

2008-12-15  Daniel Jacobowitz  <dan@codesourcery.com>

	* configure, config.in: Regenerated.
	* configure.ac: Add --with-system-gdbinit.
	* main.c (system_gdbinit): New.
	(captured_main): Relocate system_gdbinit.  Load it before
	$HOME/.gdbinit.

2008-12-15  Daniel Jacobowitz  <dan@codesourcery.com>

	* gdb.texinfo (Startup): Document --with-system-gdbinit.

Index: config.in
===================================================================
RCS file: /cvs/src/src/gdb/config.in,v
retrieving revision 1.103
diff -u -p -r1.103 config.in
--- config.in	6 Aug 2008 19:41:31 -0000	1.103
+++ config.in	15 Dec 2008 15:40:34 -0000
@@ -646,6 +646,13 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
+/* System-wide gdbinit file. */
+#undef SYSTEM_GDBINIT
+
+/* Define if the system-wide gdbinit file should be relocated when GDB is
+   moved. */
+#undef SYSTEM_GDBINIT_RELOCATABLE
+
 /* Define if <thread_db.h> has the TD_NOTALLOC error code. */
 #undef THREAD_DB_HAS_TD_NOTALLOC
 
Index: configure
===================================================================
RCS file: /cvs/src/src/gdb/configure,v
retrieving revision 1.262
diff -u -p -r1.262 configure
--- configure	21 Nov 2008 22:35:57 -0000	1.262
+++ configure	15 Dec 2008 15:40:36 -0000
@@ -895,6 +895,7 @@ Optional Packages:
                           on systems with version 2 of the GNU C library
                           (use with caution on other system)
   --with-sysroot=DIR Search for usr/lib et al within DIR.
+  --with-system-gdbinit=file       Automatically load a system-wide gdbinit file
   --with-tcl              directory containing tcl configuration (tclConfig.sh)
   --with-tk               directory containing tk configuration (tkConfig.sh)
   --with-x                use the X Window System
@@ -19417,6 +19418,49 @@ fi;
 
 
 
+system_gdbinit=
+
+# Check whether --with-system-gdbinit or --without-system-gdbinit was given.
+if test "${with_system_gdbinit+set}" = set; then
+  withval="$with_system_gdbinit"
+  system_gdbinit=${withval}
+fi;
+
+
+  test "x$prefix" = xNONE && prefix="$ac_default_prefix"
+  test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
+  ac_define_dir=`eval echo $system_gdbinit`
+  ac_define_dir=`eval echo $ac_define_dir`
+
+cat >>confdefs.h <<_ACEOF
+#define SYSTEM_GDBINIT "$ac_define_dir"
+_ACEOF
+
+
+
+if test "x$prefix" = xNONE; then
+  test_prefix=$ac_default_prefix
+else
+  test_prefix=$prefix
+fi
+if test "x$exec_prefix" = xNONE || test "x$exec_prefix" = 'x${prefix}'; then
+  test_exec_prefix=$test_prefix
+else
+  test_exec_prefix=$exec_prefix
+fi
+case ${system_gdbinit} in
+ "${test_prefix}"|"${test_prefix}/"*|\
+ "${test_exec_prefix}"|"${test_exec_prefix}/"*|\
+ '${prefix}'|'${prefix}/'*|\
+ '${exec_prefix}'|'${exec_prefix}/'*)
+
+cat >>confdefs.h <<\_ACEOF
+#define SYSTEM_GDBINIT_RELOCATABLE 1
+_ACEOF
+
+   ;;
+esac
+
 # Check whether --enable-werror or --disable-werror was given.
 if test "${enable_werror+set}" = set; then
   enableval="$enable_werror"
Index: configure.ac
===================================================================
RCS file: /cvs/src/src/gdb/configure.ac,v
retrieving revision 1.82
diff -u -p -r1.82 configure.ac
--- configure.ac	21 Nov 2008 22:35:58 -0000	1.82
+++ configure.ac	15 Dec 2008 15:40:36 -0000
@@ -1488,6 +1488,34 @@ AC_ARG_WITH(sysroot,
 AC_SUBST(TARGET_SYSTEM_ROOT)
 AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE)
 
+system_gdbinit=
+AC_ARG_WITH(system-gdbinit,
+[  --with-system-gdbinit=file       Automatically load a system-wide gdbinit file],
+[system_gdbinit=${withval}])
+
+AC_DEFINE_DIR(SYSTEM_GDBINIT, system_gdbinit,
+              [System-wide gdbinit file.])
+
+if test "x$prefix" = xNONE; then
+  test_prefix=$ac_default_prefix
+else
+  test_prefix=$prefix
+fi
+if test "x$exec_prefix" = xNONE || test "x$exec_prefix" = 'x${prefix}'; then
+  test_exec_prefix=$test_prefix
+else
+  test_exec_prefix=$exec_prefix
+fi
+case ${system_gdbinit} in
+ "${test_prefix}"|"${test_prefix}/"*|\
+ "${test_exec_prefix}"|"${test_exec_prefix}/"*|\
+ '${prefix}'|'${prefix}/'*|\
+ '${exec_prefix}'|'${exec_prefix}/'*)
+  AC_DEFINE(SYSTEM_GDBINIT_RELOCATABLE, 1,
+            [Define if the system-wide gdbinit file should be relocated when GDB is moved.])
+   ;;
+esac
+
 AC_ARG_ENABLE(werror,
   [  --enable-werror    treat compile warnings as errors],
   [case "${enableval}" in
Index: main.c
===================================================================
RCS file: /cvs/src/src/gdb/main.c,v
retrieving revision 1.70
diff -u -p -r1.70 main.c
--- main.c	29 Jul 2008 14:16:15 -0000	1.70
+++ main.c	15 Dec 2008 15:40:36 -0000
@@ -83,6 +83,9 @@ int return_child_result_value = -1;
 /* Whether to enable writing into executable and core files */
 extern int write_files;
 
+/* The system-wide gdbinit file.  */
+static char *system_gdbinit = SYSTEM_GDBINIT;
+
 static void print_gdb_help (struct ui_file *);
 
 /* These two are used to set the external editor commands when gdb is farming
@@ -268,6 +271,24 @@ captured_main (void *data)
 	}
     }
 
+#ifdef SYSTEM_GDBINIT_RELOCATABLE
+  system_gdbinit = make_relative_prefix (argv[0], BINDIR, SYSTEM_GDBINIT);
+  if (system_gdbinit)
+    {
+      struct stat s;
+      int res = 0;
+
+      if (stat (system_gdbinit, &s) == 0)
+	res = 1;
+
+      if (res == 0)
+	{
+	  xfree (system_gdbinit);
+	  system_gdbinit = SYSTEM_GDBINIT;
+	}
+    }
+#endif
+
   /* There will always be an interpreter.  Either the one passed into
      this captured main, or one specified by the user at start up, or
      the console.  Initialize the interpreter to the one requested by 
@@ -679,6 +700,13 @@ Excess command line arguments ignored. (
   quit_pre_print = error_pre_print;
   warning_pre_print = _("\nwarning: ");
 
+  /* Read and execute the system-wide gdbinit file, if it exists.
+     This is done *before* all the command line arguments are
+     processed; it sets global parameters, which are independent of
+     what file you are debugging or what directory you are in.  */
+  if (system_gdbinit[0] && !inhibit_gdbinit)
+    catch_command_errors (source_script, system_gdbinit, 0, RETURN_MASK_ALL);
+
   /* Read and execute $HOME/.gdbinit file, if it exists.  This is done
      *before* all the command line arguments are processed; it sets
      global parameters, which are independent of what file you are
Index: doc/gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.537
diff -u -p -r1.537 gdb.texinfo
--- doc/gdb.texinfo	27 Nov 2008 09:23:01 -0000	1.537
+++ doc/gdb.texinfo	15 Dec 2008 15:40:42 -0000
@@ -1219,6 +1219,10 @@ Sets up the command interpreter as speci
 
 @item
 @cindex init file
+Reads the system-wide @dfn{init file} (if @option{--with-system-gdbinit} was
+used when building @value{GDBN}) and executes all the commands in that file.
+
+@item
 Reads the @dfn{init file} (if any) in your home directory@footnote{On
 DOS/Windows systems, the home directory is the one pointed to by the
 @code{HOME} environment variable.} and executes all the commands in