revert r133003 and fix the bug properly: the issue was that ## in a token

lexer is not a paste operator, it is a normal token.  This fixes a conformance
issue shown here:
http://p99.gforge.inria.fr/c99-conformance/c99-conformance-clang-2.9.html

and it defines away the crash from before.

llvm-svn: 133005

2 files changed, 11 insertions, 9 deletions

diff --git a/clang/test/Preprocessor/macro_paste_bad.c b/clang/test/Preprocessor/macro_paste_bad.c
index 1c0b74ba298..0a028a44686 100644
--- a/clang/test/Preprocessor/macro_paste_bad.c
+++ b/clang/test/Preprocessor/macro_paste_bad.c
@@ -32,10 +32,3 @@ XX     // expected-error {{attempt to use a poisoned identifier}}
 #define VA __VA_ ## ARGS__
 int VA;   // expected-warning {{__VA_ARGS__ can only appear in the expansion of a C99 variadic macro}}
 
-
-// PR9981
-#define M1(A) A
-#define M2(X) 
-M1(M2(##))   // expected-error {{pasting formed '()', an invalid preprocessing token}}
-
-
diff --git a/clang/test/Preprocessor/macro_paste_simple.c b/clang/test/Preprocessor/macro_paste_simple.c
index 563d7f44958..0e62ba46dc9 100644
--- a/clang/test/Preprocessor/macro_paste_simple.c
+++ b/clang/test/Preprocessor/macro_paste_simple.c
@@ -1,5 +1,14 @@
-// RUN: %clang_cc1 %s -E | grep "barbaz123"
+// RUN: %clang_cc1 %s -E | FileCheck %s
 
 #define FOO bar ## baz ## 123
 
-FOO
+// CHECK: A: barbaz123
+A: FOO
+
+// PR9981
+#define M1(A) A
+#define M2(X) X
+B: M1(M2(##))
+
+// CHECK: B: ##
+