build-sys: omit mustach compilation when it cannot work

For example mac does not have open_memstream(3), and strndupa(3) can also be
missing.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

configure.ac

@@ -69,8 +69,18 @@ AC_TYPE_UINT32_T
 AC_FUNC_ERROR_AT_LINE
 AC_CHECK_FUNCS([\
 	__fpending \
+	open_memstream \
 	posix_fadvise \
 ])
+AC_CHECK_DECL([strndupa])
+
+AS_IF([test "x$ac_cv_func_open_memstream" = "xyes" && test "x$ac_cv_have_decl_strndupa" == "xyes"], [
+	build_mustach=yes
+	AC_DEFINE([BUILD_MUSTACH], [1], [build mustach support])
+], [
+	build_mustach=no
+])
+AM_CONDITIONAL([ENABLE_MUSTACH], [test "x$build_mustach" = xyes])
 
 AC_MSG_CHECKING([if the compiler supports __builtin_expect])
 AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[

src/Makemodule.am

@@ -13,9 +13,13 @@ dhcpd_pools_SOURCES = \
 	src/dhcpd-pools.h \
 	src/getdata.c \
 	src/hash.c \
-	src/mustach-dhcpd-pools.c \
-	src/mustach.c \
-	src/mustach.h \
 	src/other.c \
 	src/output.c \
 	src/sort.c
+
+if ENABLE_MUSTACH
+dhcpd_pools_SOURCES += \
+	src/mustach-dhcpd-pools.c \
+	src/mustach.c \
+	src/mustach.h
+endif

src/dhcpd-pools.c

@@ -127,7 +127,9 @@ int main(int argc, char **argv)
 		{"reverse", no_argument, NULL, 'r'},
 		{"output", required_argument, NULL, 'o'},
 		{"limit", required_argument, NULL, 'L'},
+#ifdef BUILD_MUSTACH
 		{"mustach", required_argument, NULL, OPT_MUSTACH},
+#endif
 		{"version", no_argument, NULL, 'v'},
 		{"help", no_argument, NULL, 'h'},
 		{"snet-alarms", no_argument, NULL, OPT_SNET_ALARMS},
@@ -227,10 +229,12 @@ int main(int argc, char **argv)
 			config.header_limit = return_limit(optarg[0]);
 			config.number_limit = return_limit(optarg[1]);
 			break;
+#ifdef BUILD_MUSTACH
 		case OPT_MUSTACH:
 			config.mustach_template = optarg;
 			output_format = 'm';
 			break;
+#endif
 		case OPT_COLOR:
 			config.color_mode = parse_color_mode(optarg);
 			if (config.color_mode == color_unknown)

src/other.c

@@ -567,6 +567,9 @@ void __attribute__ ((__noreturn__)) usage(int status)
 	fputs(		"                           j for json\n", out);
 	fputs(		"                           J for json with active lease details\n", out);
 	fputs(		"                           c for comma separated values\n", out);
+#ifdef BUILD_MUSTACH
+	fputs(		"      --mustach=tmpl     output using mustach template file\n", out);
+#endif
 	fputs(		"  -s, --sort=[nimcptTe]  sort ranges by\n", out);
 	fputs(		"                           n name\n", out);
 	fputs(		"                           i IP\n", out);

src/output.c

@@ -1267,9 +1267,11 @@ int output_analysis(const char c)
 	case 'c':
 		ret = output_csv();
 		break;
+#ifdef BUILD_MUSTACH
 	case 'm':
 		ret = mustach_dhcpd_pools();
 		break;
+#endif
 	default:
 		error(EXIT_FAILURE, 0, "unknown output format: '%c'", c);
 	}

tests/Makemodule.am

@@ -18,7 +18,6 @@ TESTS = \
 	tests/full-json \
 	tests/full-xml \
 	tests/leading0 \
-	tests/mustach \
 	tests/one-ip \
 	tests/one-line \
 	tests/range4 \
@@ -29,6 +28,11 @@ TESTS = \
 	tests/v6 \
 	tests/v6-perfdata
 
+if ENABLE_MUSTACH
+TESTS += \
+	tests/mustach
+endif
+
 EXTRA_DIST += \
 	tests/confs \
 	tests/expected \