Add another terrible VC++ compatibility hack: allow users to

allow invalid token pastes (when in -fms-extensions mode)
with -Wno-invalid-token-paste


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108624 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 18 insertions, 2 deletions

diff --git a/include/clang/Basic/DiagnosticLexKinds.td b/include/clang/Basic/DiagnosticLexKinds.td
index 21c93e7e8f..41e9feff2d 100644
--- a/include/clang/Basic/DiagnosticLexKinds.td
+++ b/include/clang/Basic/DiagnosticLexKinds.td
@@ -277,6 +277,9 @@ def err_too_few_args_in_macro_invoc : Error<
   "too few arguments provided to function-like macro invocation">;
 def err_pp_bad_paste : Error<
   "pasting formed '%0', an invalid preprocessing token">;
+def err_pp_bad_paste_ms : Warning<
+  "pasting formed '%0', an invalid preprocessing token">, DefaultError,
+  InGroup<DiagGroup<"invalid-token-paste">>;
 def err_pp_operator_used_as_macro_name : Error<
   "C++ operator '%0' cannot be used as a macro name">;
 def err_pp_illegal_floating_literal : Error<
diff --git a/lib/Lex/TokenLexer.cpp b/lib/Lex/TokenLexer.cpp
index 56bb073e59..55609492a7 100644
--- a/lib/Lex/TokenLexer.cpp
+++ b/lib/Lex/TokenLexer.cpp
@@ -478,7 +478,7 @@ bool TokenLexer::PasteTokens(Token &Tok) {
           return true;
         }
 
-        // Do not emit the warning when preprocessing assembler code.
+        // Do not emit the error when preprocessing assembler code.
         if (!PP.getLangOptions().AsmPreprocessor) {
           // Explicitly convert the token location to have proper instantiation
           // information so that the user knows where it came from.
@@ -486,7 +486,12 @@ bool TokenLexer::PasteTokens(Token &Tok) {
           SourceLocation Loc =
             SM.createInstantiationLoc(PasteOpLoc, InstantiateLocStart,
                                       InstantiateLocEnd, 2);
-          PP.Diag(Loc, diag::err_pp_bad_paste)
+          // If we're in microsoft extensions mode, downgrade this from a hard
+          // error to a warning that defaults to an error.  This allows
+          // disabling it.
+          PP.Diag(Loc,
+                  PP.getLangOptions().Microsoft ? diag::err_pp_bad_paste_ms 
+                                                : diag::err_pp_bad_paste)
             << std::string(Buffer.begin(), Buffer.end());
         }
 
diff --git a/test/Preprocessor/macro_paste_msextensions.c b/test/Preprocessor/macro_paste_msextensions.c
index 71324064f7..c5b42130b8 100644
--- a/test/Preprocessor/macro_paste_msextensions.c
+++ b/test/Preprocessor/macro_paste_msextensions.c
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -P -E -fms-extensions %s | FileCheck -strict-whitespace %s
+
 // This horrible stuff should preprocess into (other than whitespace):
 //   int foo;
 //   int bar;
@@ -24,3 +25,10 @@ nested(baz)  rise of the dead tokens
 // CHECK: int baz
 // CHECK: ;
 
+
+// rdar://8197149 - VC++ allows invalid token pastes: (##baz
+#define foo(x) abc(x)
+#define bar(y) foo(##baz(y))
+bar(q)
+
+// CHECK: abc(baz(q))