build system: posix make support: handle out-of-tree builds in posix make mode.

1 files changed, 83 insertions, 0 deletions

diff --git a/sofort/tools/srctree.sh b/sofort/tools/srctree.sh
new file mode 100755
index 0000000..90a1d89
--- /dev/null
+++ b/sofort/tools/srctree.sh
@@ -0,0 +1,83 @@
+#!/bin/sh
+
+# srctree.sh: support for out-of-tree builds in posix make mode.
+# this file is covered by COPYING.SOFORT.
+
+set -eu
+
+usage()
+{
+cat << EOF >&2
+
+Usage:
+  --help              show this HELP message
+  --srctree=SRCTREE   set source directory
+
+EOF
+exit 1
+}
+
+
+# one
+workdir=$(pwd -P)
+srctree=
+argloop=
+
+
+for arg ; do
+	case "$arg" in
+		--help)
+			usage
+			;;
+
+		--srctree=*)
+			srctree=${arg#*=}
+			;;
+
+		--)
+			argloop='done'
+			;;
+
+		*)
+			if [ -z "$argloop" ]; then
+				printf 'Invalid option: %s\n' "$arg" >&2
+				usage
+			fi
+			;;
+	esac
+done
+
+
+# two
+if [ -z "$srctree" ] ; then
+	usage
+fi
+
+cd -- "$srctree"
+srctree=$(pwd -P)
+cd -- "$workdir"
+
+if [ "$srctree" = "$workdir" ]; then
+	exit 0
+fi
+
+
+# three
+for arg ; do
+	case "$arg" in
+		--srctree=*)
+			;;
+
+		--)
+			;;
+
+		*)
+			stat "$arg" > /dev/null 2>&1 \
+				|| ln -s -- "$srctree/$arg" "$arg"
+			;;
+	esac
+done
+
+
+# all done
+exit 0