Fix PR1820, an incredibly subtle macro expansion bug that Neil discovered.
Neil, please review this fix.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44285 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/macro_disable4.c b/test/Preprocessor/macro_disable4.c
new file mode 100644
index 0000000..4858813
--- /dev/null
+++ b/test/Preprocessor/macro_disable4.c
@@ -0,0 +1,6 @@
+// RUN: clang -P -E %s | grep 'int f(void)'
+// PR1820
+
+#define f(x) h(x
+#define h(x) x(void)
+extern int f(f));