[PATCH 2/2] gdb/testsuite: avoid temporary file in gdb/testsuite

[Andrew Burgess <aburgess@redhat.com>]

I spotted that the gdb.gdb/unittest.exp script causes a temporary file
inserters_extractors-2.txt to be created in build/gdb/testsuite/
instead of in build/gdb/testsuite/output/gdb.gdb/unittest/.

This is because some of the 'maint selftest' tests create temporary
files in GDB's current directory, specifically, the two source files:

  gdb/unittests/basic_string_view/inserters/wchar_t/2.cc
  gdb/unittests/basic_string_view/inserters/char/2.cc

both create a temporary file called inserters_extractors-2.txt, though
we only run the second of these as part of GDB's selftests.

I propose that in the gdb.gdb/unittest.exp we change GDB's current
working directory to be the output directory for the specific test,
that way the temporary file will be created in the correct place.

After this change all the tests continue to pass, and the temporary
file is no longer left in gdb/testsuite/.
---
 gdb/testsuite/gdb.gdb/unittest.exp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/gdb/testsuite/gdb.gdb/unittest.exp b/gdb/testsuite/gdb.gdb/unittest.exp
index 2967b994cc3..a60cd70a259 100644
--- a/gdb/testsuite/gdb.gdb/unittest.exp
+++ b/gdb/testsuite/gdb.gdb/unittest.exp
@@ -40,6 +40,14 @@ proc run_selftests { binfile } {
 	clean_restart ${binfile}
     }
 
+    # Some of the selftests create temporary files in GDB's current
+    # directory.  So, while running the selftests, switch to the
+    # test's output directory to avoid leaving clutter in the
+    # gdb/testsuite root directory.
+    set dir [standard_output_file ""]
+    gdb_test "cd $dir" "Working directory $dir\\." \
+	"switch to test output directory"
+
     set enabled 1
     set test "maintenance selftest"
     gdb_test_multiple $test $test {
-- 
2.25.4