Add self-test framework to gdb

I wanted to unit test the Rust lexer, so I added a simple unit testing
command to gdb.

The intent is that self tests will only be compiled into gdb in
development mode.  In release mode they simply won't exist.  So, this
exposes $development to C code as GDB_SELF_TEST.

In development mode, test functions are registered with the self test
module.  A test function is just a function that does some checks, and
throws an exception on failure.

Then this adds a new "maint selftest" command which invokes the test
functions, and a new dejagnu test case that invokes it.

2016-05-17  Tom Tromey  <tom@tromey.com>

	* NEWS: Add "maint selftest" entry.
	* selftest.h: New file.
	* selftest.c: New file.
	* maint.c: Include selftest.h.
	(maintenance_selftest): New function.
	(_initialize_maint_cmds): Add "maint selftest" command.
	* configure.ac (GDB_SELF_TEST): Maybe define.
	* config.in, configure: Rebuild.
	* Makefile.in (SFILES): Add selftest.c.
	(COMMON_OBS): Add selftest.o.

2016-05-17  Tom Tromey  <tom@tromey.com>

	* gdb.texinfo (Maintenance Commands): Document "maint selftest".

2016-05-17  Tom Tromey  <tom@tromey.com>

	* gdb.gdb/unittest.exp: New file.

1 files changed, 67 insertions, 0 deletions

diff --git a/gdb/selftest.c b/gdb/selftest.c
new file mode 100644
index 0000000..c63c06d
--- /dev/null
+++ b/gdb/selftest.c
@@ -0,0 +1,67 @@
+/* GDB self-testing.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "selftest.h"
+#include "vec.h"
+
+typedef self_test_function *self_test_function_ptr;
+
+DEF_VEC_P (self_test_function_ptr);
+
+/* All the tests that have been registered.  */
+
+static VEC (self_test_function_ptr) *tests;
+
+/* See selftest.h.  */
+
+void
+register_self_test (self_test_function *function)
+{
+  VEC_safe_push (self_test_function_ptr, tests, function);
+}
+
+/* See selftest.h.  */
+
+void
+run_self_tests (void)
+{
+  int i;
+  self_test_function_ptr func;
+  int failed = 0;
+
+  for (i = 0; VEC_iterate (self_test_function_ptr, tests, i, func); ++i)
+    {
+      QUIT;
+
+      TRY
+	{
+	  (*func) ();
+	}
+      CATCH (ex, RETURN_MASK_ERROR)
+	{
+	  ++failed;
+	  exception_fprintf (gdb_stderr, ex,
+			     _("Self test threw exception"));
+	}
+      END_CATCH
+    }
+
+  printf_filtered (_("Ran %u unit tests, %d failed\n"),
+		   VEC_length (self_test_function_ptr, tests), failed);
+}