configure.ac: fix build without C++

Makefile.am

@@ -105,7 +105,9 @@ gumbo_test_DEPENDENCIES += check-local
 gumbo_test_LDADD += gtest/lib/libgtest.la gtest/lib/libgtest_main.la
 endif
 
+if HAVE_EXAMPLES
 noinst_PROGRAMS = clean_text find_links get_title positions_of_class benchmark serialize prettyprint
+endif
 LDADD = libgumbo.la
 AM_CPPFLAGS = -I"$(srcdir)/src"
 

configure.ac

@@ -9,8 +9,8 @@ AC_CONFIG_SRCDIR([src/parser.c])
 AC_CONFIG_FILES([Makefile gumbo.pc])
 
 # Checks for programs.
-AC_PROG_CXX
 AC_PROG_CC_C99
+AC_PROG_CXX
 
 # Checks for libraries.
 
@@ -27,6 +27,10 @@ AC_CHECK_LIB([gtest_main],
              AM_CONDITIONAL(HAVE_SHARED_LIBGTEST, [true]),
              AM_CONDITIONAL(HAVE_SHARED_LIBGTEST, [false]))
 
+AC_ARG_ENABLE([examples],
+              AS_HELP_STRING([--disable-examples], [Disable examples]))
+AM_CONDITIONAL([HAVE_EXAMPLES], [test "x$enable_examples" != "xno"])
+
 # Init Automake & libtool
 AM_INIT_AUTOMAKE([foreign subdir-objects])
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])