Support coverage flushing on assert()

When assert() is called, which is not uncommon in utility code within NetSurf,
we lose coverage data for anything done before the assert() in the test.  This
commit corrects that oversight but is at least slightly GCC specific and may
need tweaks for non-Linux platforms.

By default, 'make coverage' will enable assert coverage, and it can be disabled
with 'make coverage NOASSERTCOVERAGE=yes' if necessary.

Signed-off-by: Daniel Silverstone <dsilvers@netsurf-browser.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/test/assert.c b/test/assert.c
new file mode 100644
index 000000000..d21926e5e
--- /dev/null
+++ b/test/assert.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2017 Daniel Silverstone <dsilvers@netsurf-browser.org>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf 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; version 2 of the License.
+ *
+ * NetSurf 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/>.
+ */
+
+/**
+ * \file
+ * Hack for assertion coverage output
+ */
+
+/* Bring in the real __assert_fail */
+#include <assert.h>
+
+/* This is what everyone else calls */
+extern void
+__ns_assert_fail(const char *__assertion, const char *__file,
+		 unsigned int __line, const char *__function)
+	__THROW __attribute__ ((__noreturn__));
+
+/* We use this to flush coverage data */
+extern void __gcov_flush(void);
+
+/* And here's our entry point */
+void
+__ns_assert_fail(const char *__assertion, const char *__file,
+		 unsigned int __line, const char *__function)
+{
+	__gcov_flush();
+	__assert_fail(__assertion, __file, __line, __function);
+}