Add an implementation of -dM that follows GCC closely enough to permit
diffing the output of:
  clang -dM -o - -E -x c foo.c | sort


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63926 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/dump_macros.c b/test/Preprocessor/dump_macros.c
new file mode 100644
index 0000000..348257f
--- /dev/null
+++ b/test/Preprocessor/dump_macros.c
@@ -0,0 +1,31 @@
+// RUN: clang -E -dM %s -o %t &&
+
+// Space even without expansion tokens
+// RUN: grep "#define A(x) " %t &&
+#define A(x)
+
+// Space before expansion list.
+// RUN: grep "#define B(x,y) x y" %t &&
+#define B(x,y)x y
+
+// No space in expansion list.
+// RUN: grep "#define C(x,y) x y" %t &&
+#define C(x, y) x y
+
+// No paste avoidance.
+// RUN: grep "#define X() .." %t &&
+#define X() ..
+
+// Simple test.
+// RUN: grep "#define Y ." %t &&
+// RUN: grep "#define Z X()Y" %t &&
+#define Y .
+#define Z X()Y
+
+// gcc prints macros at end of translation unit, so last one wins.
+// RUN: grep "#define foo 2" %t &&
+// RUN: not grep "#define foo 1" %t
+#define foo 1
+#undef foo
+#define foo 2
+