diff -r 000000000000 -r 6474c204b198 build/unix/add_phony_targets.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/unix/add_phony_targets.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,33 @@
+import pymake.data
+import pymake.parser
+import pymake.parserdata
+import sys
+
+'''
+Modifies the output of Sun Studio's -xM to look more like the output
+of gcc's -MD -MP, adding phony targets for dependencies.
+'''
+
+
+def add_phony_targets(path):
+    print path
+    deps = set()
+    targets = set()
+    for stmt in pymake.parser.parsefile(path):
+        if isinstance(stmt, pymake.parserdata.Rule):
+            assert isinstance(stmt.depexp, pymake.data.StringExpansion)
+            assert isinstance(stmt.targetexp, pymake.data.StringExpansion)
+            for d in stmt.depexp.s.split():
+                deps.add(d)
+            for t in stmt.targetexp.s.split():
+                targets.add(t)
+    phony_targets = deps - targets
+    if not phony_targets:
+        return
+    with open(path, 'a') as f:
+        f.writelines('%s:\n' % d for d in phony_targets)
+
+
+if __name__ == '__main__':
+    for f in sys.argv[1:]:
+        add_phony_targets(f)