meson: Add dist target

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

Makefile.am

@@ -587,3 +587,8 @@ coverage-clean:
 
 .PHONY: .FORCE
 .FORCE:
+
+EXTRA_DIST += \
+	doc/meson.build \
+	subprojects/libgwater/xcb/meson.build \
+	meson.build

meson.build

@@ -439,3 +439,5 @@ if ohcount.found()
         ],
     )
 endif
+
+run_target('dist', command: [ 'script/dist.sh' ])

script/dist.sh

@@ -0,0 +1,21 @@
+#! /bin/sh
+
+NAME=`mesonintrospect ${MESON_BUILD_ROOT} --projectinfo | tr ',[' '\n\n' | sed -n 1,/subprojects/p | grep name | cut -d'"' -f4`
+VERSION=`mesonintrospect ${MESON_BUILD_ROOT} --projectinfo | tr ',[' '\n\n' | sed -n 1,/subprojects/p | grep version | cut -d'"' -f4`
+PREFIX=${NAME}-${VERSION}
+TAR=${MESON_BUILD_ROOT}/${PREFIX}.tar
+
+rm -f ${TAR} ${TAR}.xz
+git archive --prefix=${PREFIX}/ --format=tar HEAD > ${TAR}
+(
+    git submodule | \
+    while read commit path ref; do
+        (
+            cd ${path}
+            git archive --prefix=${PREFIX}/${path}/ --format=tar ${commit} > tmp.tar
+            tar -Af ${TAR} tmp.tar
+            rm -f tmp.tar
+        )
+    done
+)
+xz ${TAR}