New script to create a source package for Langkit_Support

TN: TA19-011

utils/langkit_support.gpr.patch

@@ -0,0 +1,16 @@
+--- langkit_support.gpr.old
++++ langkit_support.gpr
+@@ -53,10 +53,10 @@
+       "Langkit_Support.Tree_Traversal_Iterator",
+       "Langkit_Support.Vectors");
+
+-   for Source_Dirs use ("/tmp/langkit-21.0.0/langkit/support");
++   for Source_Dirs use ("src");
+    for Library_Dir use
+-      "../langkit_support/" & Library_Kind_Param & "/" & Build_Mode;
+-   for Object_Dir use "../../obj/langkit_support/" & Build_Mode;
++      "lib/" & Library_Kind_Param & "/" & Build_Mode;
++   for Object_Dir use "obj/" & Build_Mode;
+
+    Common_Ada_Cargs := ("-gnatwa", "-gnatyg", "-fPIC");
+

utils/release-langkit_support.sh

@@ -0,0 +1,27 @@
+#! /bin/sh
+
+set -e
+
+RELEASE=21.0.0
+SRC_PKG=/tmp/langkit_support-$RELEASE.tar.gz
+
+# Make sure the appropriate Langkit sources are checked out in
+# /tmp/langkit-$RELEASE
+SRC_DIR=/tmp/langkit-$RELEASE
+export PYTHONPATH=$SRC_DIR:$PYTHONPATH
+
+BUILD_DIR=/tmp/langkit_support-$RELEASE
+rm -rf $BUILD_DIR
+
+# Generate "langkit_support.gpr", move it to the top directory and import
+# sources. Then adjust source/object/library dirs.
+$SRC_DIR/scripts/build-langkit_support.py --build-dir=$BUILD_DIR generate
+mv $BUILD_DIR/lib/gnat/langkit_support.gpr $BUILD_DIR/
+rm -r $BUILD_DIR/lib
+mkdir $BUILD_DIR/src
+cp -ar $SRC_DIR/langkit/support/*.ad* $BUILD_DIR/src
+patch -d $BUILD_DIR -p0 -f -i $SRC_DIR/utils/langkit_support.gpr.patch
+
+# Create the release tarball
+tar czf $SRC_PKG -C /tmp langkit_support-$RELEASE
+sha512sum $SRC_PKG