test: add a build-test for -pedantic

We don't build with -pedantic, but a caller may try to actually stick to the
c99 standard, so let's make sure our public header doesn't cause any
issues there.

Likewise, make sure that our header compiles with GNU C90.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

test/Makefile.am

@@ -2,9 +2,16 @@ if BUILD_TESTS
 AM_CPPFLAGS = -I$(top_srcdir)/src 
 
 run_tests =
-build_tests =
+build_tests = test-build-pedantic-c99 test-build-std-gnuc90
 
 noinst_PROGRAMS = $(build_tests) $(run_tests)
 TESTS = $(run_tests)
 
+# build-test only
+test_build_pedantic_c99_SOURCES = build-pedantic.c
+test_build_pedantic_c99_CFLAGS = $(AM_CPPFLAGS) -std=c99 -pedantic -Werror
+
+test_build_std_gnuc90_SOURCES = build-pedantic.c
+test_build_std_gnuc90_CFLAGS = $(AM_CPPFLAGS) -std=gnu90 -Werror
+
 endif

test/build-pedantic.c

@@ -0,0 +1,8 @@
+#include <libinput.h>
+
+/* This is a build-test only */
+
+int
+main(int argc, char **argv) {
+	return 0;
+}