Provide mechanism to track library dependencies

Now, ar/lib rules can list static libraries or other .d files. These (as well as
the target library) are written to a file called $lib.d. link/exe rules can list
these .d files, causing them to be flattened into an RSP file and appear on the
command line as @$rsp.

The rule to generate the dependency list files depends on the libraries they
contain, so they also act as a stamp file for the dependencies. This gives us
dependency management for free.

1 files changed, 34 insertions, 0 deletions

diff --git a/scripts/rsp.awk b/scripts/rsp.awk
new file mode 100644
index 00000000..d157e249
--- /dev/null
+++ b/scripts/rsp.awk
@@ -0,0 +1,34 @@
+function line() {
+	if (match($0, /\.d$/))
+		read($0)
+	else
+		libs[++n] = $0
+}
+
+function read(name) {
+	for (;;) {
+		ret = getline < name
+		if (ret < 0) {
+			print "failed to read line from " name > "/proc/self/fd/2"
+			exit(1)
+		}
+		if (ret == 0)
+			break
+		line()
+	}
+	close(name)
+}
+
+{line()}
+
+END {
+	for (i = n; i > 0; --i) {
+		lib = libs[i]
+		if (lib in seen)
+			continue
+		seen[lib] = 1
+		uniq[++m] = lib
+	}
+	for (i = m; i > 0; --i)
+		print uniq[i]
+}