Fix issue where a token paste which forms a /* or // would discard the rest of

the input: token-pasting was producing a tok::eof.

Patch by Andy Gibbs!

llvm-svn: 158412

3 files changed, 12 insertions, 2 deletions

diff --git a/clang/lib/Lex/TokenLexer.cpp b/clang/lib/Lex/TokenLexer.cpp
index 696754c7416..81c9d0ab7ae 100644
--- a/clang/lib/Lex/TokenLexer.cpp
+++ b/clang/lib/Lex/TokenLexer.cpp
@@ -568,8 +568,8 @@ bool TokenLexer::PasteTokens(Token &Tok) {
             << Buffer.str();
         }
 
-        // Do not consume the RHS.
-        --CurToken;
+        // An error has occurred so exit loop.
+        break;
       }
 
       // Turn ## into 'unknown' to avoid # ## # from looking like a paste
diff --git a/clang/test/Preprocessor/macro_paste_c_block_comment.c b/clang/test/Preprocessor/macro_paste_c_block_comment.c
index c690a4c7c9f..92b2f601885 100644
--- a/clang/test/Preprocessor/macro_paste_c_block_comment.c
+++ b/clang/test/Preprocessor/macro_paste_c_block_comment.c
@@ -3,3 +3,6 @@
 #define COMM / ## *
 COMM // expected-error {{pasting formed '/*', an invalid preprocessing token}}
 
+// Demonstrate that an invalid preprocessing token
+// doesn't swallow the rest of the file...
+#error EOF // expected-error {{EOF}}
diff --git a/clang/test/Preprocessor/macro_paste_identifier_error.c b/clang/test/Preprocessor/macro_paste_identifier_error.c
new file mode 100644
index 00000000000..457e6f7fc1a
--- /dev/null
+++ b/clang/test/Preprocessor/macro_paste_identifier_error.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fms-extensions -Wno-invalid-token-paste %s -verify
+// RUN: %clang_cc1 -E -fms-extensions -Wno-invalid-token-paste %s | FileCheck %s
+// RUN: %clang_cc1 -E -fms-extensions -Wno-invalid-token-paste -x assembler-with-cpp %s | FileCheck %s
+
+#define foo a ## b ## = 0
+int foo;
+// CHECK: int ab = 0;