[patch] gdb.exp (INTERNAL_GDBFLAGS): Don't override value provided by user.

[dje@google.com (Doug Evans)]

Hi.

I will check this in tomorrow if there are no objections.

It is useful to run the testsuite on the installed gdb.
e.g. make check RUNTESTFLAGS=GDB=/usr/bin/gdb

When testing the installed gdb one would like to test exactly what the
user runs.  For environments that have a system.gdbinit (gdb was configured
with --with-system-gdbinit) that means using the installed system.gdbinit
and not anything from the source/build tree.
In order to do this one either needs to not pass "-nx" when dejagnu starts gdb
or pass "-x /path/to/system.gdbinit" in addition to -nx.
I like the former as it's closer to what the user does.

There is also the issue of not loading ~/.gdbinit when running the
testsuite, but can be solved by pointing $HOME at a directory without
a .gdbinit when running the testsuite.

[-nx also skips loading of $pwd/.gdbinit, but the testsuite build directory
generally doesn't have one and that's good enough for me for now]

2010-02-03  Doug Evans  <dje@google.com>

	* gdb.exp (INTERNAL_GDBFLAGS): Don't override value provided by user.

Index: gdb.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/lib/gdb.exp,v
retrieving revision 1.135
diff -u -p -r1.135 gdb.exp
--- gdb.exp	14 Jan 2010 21:12:00 -0000	1.135
+++ gdb.exp	4 Feb 2010 00:15:25 -0000
@@ -54,7 +54,10 @@ if ![info exists GDBFLAGS] {
 verbose "using GDBFLAGS = $GDBFLAGS" 2
 
 # INTERNAL_GDBFLAGS contains flags that the testsuite requires.
-set INTERNAL_GDBFLAGS "-nw -nx"
+global INTERNAL_GDBFLAGS
+if ![info exists INTERNAL_GDBFLAGS] {
+    set INTERNAL_GDBFLAGS "-nw -nx"
+}
 
 # The variable gdb_prompt is a regexp which matches the gdb prompt.
 # Set it if it is not already set.