[PATCH] Handle SIGSEGV in gdb selftests

[Tom Tromey <tromey@adacore.com>]

The gdb.gdb self-tests were timing out for me.  Looking into it, the
problem is that the version of the Boehm GC that is used by Guile on
my machine causes a SEGV during stack probing.  This unexpected stop
confuses the tests and causes repeated timeouts.

This patch adapts the two failing tests.  This makes them work for me,
and reduces the running time of gdb.gdb from 20 minutes to about 11
seconds.
---
 gdb/testsuite/gdb.gdb/python-helper.exp | 6 ++++++
 gdb/testsuite/gdb.gdb/selftest.exp      | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/gdb/testsuite/gdb.gdb/python-helper.exp b/gdb/testsuite/gdb.gdb/python-helper.exp
index 3585ac9f0bf..fc52929489e 100644
--- a/gdb/testsuite/gdb.gdb/python-helper.exp
+++ b/gdb/testsuite/gdb.gdb/python-helper.exp
@@ -93,6 +93,12 @@ proc test_python_helper {} {
     # here.
     gdb_test_multiple "continue" "start inner gdb" {
 	-i "$inferior_spawn_id"
+	-re "received signal SIGSEGV.* in GC_.*$outer_prompt_re" {
+	    # Some versions of the GC used by Guile cause a SEGV
+	    # during stack probing.  Ignore this and carry on.
+	    send_gdb "continue\n"
+	    exp_continue
+	}
 	-re "\r\n$gdb_prompt $" {
 	    pass $gdb_test_name
 	}
diff --git a/gdb/testsuite/gdb.gdb/selftest.exp b/gdb/testsuite/gdb.gdb/selftest.exp
index ca1e7cffb4e..e2b9247f65d 100644
--- a/gdb/testsuite/gdb.gdb/selftest.exp
+++ b/gdb/testsuite/gdb.gdb/selftest.exp
@@ -75,6 +75,12 @@ proc test_with_self { } {
 	set test "xgdb is at prompt"
 	gdb_test_multiple "continue" $test {
 	    -i "$inferior_spawn_id"
+	    -re "received signal SIGSEGV.* in GC_.*$gdb_prompt" {
+		# Some versions of the GC used by Guile cause a SEGV
+		# during stack probing.  Ignore this and carry on.
+		send_gdb "continue\n"
+		exp_continue
+	    }
 	    -re "$banner" {
 		pass $test
 	    }
-- 
2.34.3