Add auto-generated Git version to window titles

src/scmversion/gen_scmversion.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+VERSION_FILE="scmversion.cpp"
+BRANCH=$(git rev-parse --abbrev-ref HEAD | tr -d '\r\n')
+TAG=$(git describe --tags --dirty | tr -d '\r\n')
+
+SIGNATURE_LINE="// ${BRANCH} ${TAG}"
+
+if [ -f $VERSION_FILE ]; then
+  EXISTING_LINE=$(head -n1 $VERSION_FILE | tr -d '\n')
+  if [ "$EXISTING_LINE" = "$SIGNATURE_LINE" ]; then
+    echo "Signature matches, skipping writing ${VERSION_FILE}"
+    exit 0
+  fi
+fi
+
+echo "Writing ${VERSION_FILE}..."
+
+cat > $VERSION_FILE << EOF
+${SIGNATURE_LINE}
+const char* g_scm_branch_str = "${BRANCH}";
+const char* g_scm_tag_str = "${TAG}";
+
+EOF
+