[PATCH wayland] scanner: Add autoconf macro to check for the proper scanner

[Quentin Glidic]

From: Quentin Glidic <sardemff7+git at sardemff7.net>

Projects have been using various ways to check for the wayland-scanner,
mostly based on their developper own use case, and often not allowing
others use cases to work without a workaround.

Hopefully this macro will support all use cases without needing user
action.

Signed-off-by: Quentin Glidic <sardemff7+git at sardemff7.net>
---

Everyone should test this macro for their own project and use cases.
Using the ${WAYLAND_SCANNER} variable should just work (assuming you have the proper
wayland package built in the expected env). In very very rare cases, setting the
WAYLAND_SCANNER variable as a ./configure argument may be needed, but nothing else.

Please let me know with enough details if your use case is not working with it.

 wayland-scanner.m4 | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/wayland-scanner.m4 b/wayland-scanner.m4
index 4e4222a..37e0548 100644
--- a/wayland-scanner.m4
+++ b/wayland-scanner.m4
@@ -1,3 +1,5 @@
+#serial 2
+
 AC_DEFUN([WAYLAND_SCANNER_RULES], [
     PKG_PROG_PKG_CONFIG
 
@@ -11,3 +13,55 @@ AC_DEFUN([WAYLAND_SCANNER_RULES], [
 
     AC_SUBST([wayland_protocoldir], [$1])
 ])
+
+
+AC_DEFUN([_WL_PROG_WAYLAND_SCANNER_VERSION_CHECK], [
+    wl_cv_scanner_version=`${WAYLAND_SCANNER} --version 2>&1 | sed 's/^wayland-scanner //'`
+    AS_VERSION_COMPARE([${wl_cv_scanner_version}], [${wl_cv_scanner_wanted_version}], [], [
+        wl_cv_scanner_found=yes
+    ], [])
+])
+
+# WL_PROG_WAYLAND_SCANNER()
+AC_DEFUN([WL_PROG_WAYLAND_SCANNER], [
+    AC_REQUIRE([AC_CANONICAL_BUILD])
+    AC_REQUIRE([PKG_PROG_PKG_CONFIG])
+    wl_cv_native_pkg_config=
+    AS_IF([test x${cross_compiling} = xyes], [
+        wl_cv_native_pkg_config=${build}-pkg-config
+        AC_PATH_PROGS([wl_cv_native_pkg_config], [${build}-pkg-config])
+    ])
+    AC_ARG_VAR([WAYLAND_SCANNER], [wayland-scanner executable])
+    wl_cv_scanner_found=no
+    wl_cv_scanner_wanted_version=`${PKG_CONFIG} --modversion wayland-server`
+    AC_MSG_CHECKING([that wayland-client and wayland-server versions are the same])
+    AS_IF([test ${wl_cv_scanner_wanted_version} = `${PKG_CONFIG} --modversion wayland-client`], [
+        AC_MSG_RESULT([ok])
+    ], [
+        AC_MSG_ERROR([mismatch])
+    ])
+    AC_MSG_CHECKING([for wayland-scanner ${wl_cv_scanner_wanted_version}])
+    AS_IF([test x${ac_cv_env_WAYLAND_SCANNER_set} = xset], [
+        _WL_PROG_WAYLAND_SCANNER_VERSION_CHECK()
+    ])
+    AS_IF([test x${cross_compiling} = xyes -a x${wl_cv_native_pkg_config} != xno], [
+        AS_IF([AC_RUN_LOG([${wl_cv_native_pkg_config} --exists --print-errors wayland-scanner = ${wl_cv_scanner_wanted_version}])], [
+            WAYLAND_SCANNER=`${wl_cv_native_pkg_config} --variable=wayland_scanner wayland-scanner = ${wl_cv_scanner_wanted_version}`
+            _WL_PROG_WAYLAND_SCANNER_VERSION_CHECK()
+        ])
+    ])
+    AS_IF([test x${wl_cv_scanner_found} = xno], [
+        AS_IF([AC_RUN_LOG([${PKG_CONFIG} --exists --print-errors wayland-scanner = ${wl_cv_scanner_wanted_version}])], [
+            WAYLAND_SCANNER=`${PKG_CONFIG} --variable=wayland_scanner wayland-scanner = ${wl_cv_scanner_wanted_version}`
+            _WL_PROG_WAYLAND_SCANNER_VERSION_CHECK()
+        ])
+    ])
+    AS_IF([test x${wl_cv_scanner_found} = xno], [
+        AC_PATH_PROG([WAYLAND_SCANNER], [wayland-scanner])
+        _WL_PROG_WAYLAND_SCANNER_VERSION_CHECK()
+    ])
+    AS_IF([test x${wl_cv_scanner_found} = xno], [
+        AC_MSG_ERROR([no usable wayland-scanner executable version ${wl_cv_scanner_wanted_version}])
+    ])
+    AC_MSG_RESULT([${WAYLAND_SCANNER}])
+])
-- 
2.13.4