Fix the build with gperf 3.1

gperf 3.1 generates lookup functions that take a size_t length
parameter instead of unsigned int. Test for this at configure time.

Fixes: https://github.com/hughsie/appstream-glib/issues/148

2 files changed, 22 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 9055273..7f7b8da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -159,6 +159,26 @@ if test x$GPERF = xno ; then
 	AC_MSG_ERROR([gperf not found])
 fi
 
+GPERF_TEST="$(echo foo,bar | ${GPERF} -L ANSI-C)"
+AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([
+                #include <string.h>
+                const char * in_word_set(const char *, size_t);
+                $GPERF_TEST]
+        )],
+        [GPERF_LEN_TYPE=size_t],
+        [AC_COMPILE_IFELSE(
+                [AC_LANG_PROGRAM([
+                        #include <string.h>
+                        const char * in_word_set(const char *, unsigned);
+                        $GPERF_TEST]
+                )],
+                [GPERF_LEN_TYPE=unsigned],
+                [AC_MSG_ERROR([unable to determine gperf len type])]
+        )]
+)
+AC_DEFINE_UNQUOTED([GPERF_LEN_TYPE], [$GPERF_LEN_TYPE], [gperf len type])
+
 PKG_CHECK_MODULES(GLIB, glib-2.0 >= 2.45.8 gio-2.0 gobject-2.0 gthread-2.0 gio-unix-2.0 gmodule-2.0)
 PKG_CHECK_MODULES(UUID, uuid)
 PKG_CHECK_MODULES(LIBARCHIVE, libarchive)
diff --git a/libappstream-glib/as-tag.c b/libappstream-glib/as-tag.c
index 8bb9519..faf7eb0 100644
--- a/libappstream-glib/as-tag.c
+++ b/libappstream-glib/as-tag.c
@@ -35,8 +35,7 @@
 
 #include "as-tag.h"
 
-/* we need to define this now as gperf just writes a big header file */
-const struct tag_data *_as_tag_from_gperf (const char *tag, guint etag);
+const struct tag_data *_as_tag_from_gperf (const char *tag, GPERF_LEN_TYPE etag);
 #include "as-tag-private.h"
 
 /**
@@ -78,7 +77,7 @@ as_tag_from_string_full (const gchar *tag, AsTagFlags flags)
 		return AS_TAG_UNKNOWN;
 
 	/* use a perfect hash */
-	ky = _as_tag_from_gperf (tag, (guint) strlen (tag));
+	ky = _as_tag_from_gperf (tag, (GPERF_LEN_TYPE) strlen (tag));
 	if (ky != NULL)
 		etag = ky->etag;