Fix PR3635 by handling ## magically

llvm-svn: 65374

2 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Rewrite/HTMLRewrite.cpp b/clang/lib/Rewrite/HTMLRewrite.cpp
index cf49701a1d7..0ef998deb13 100644
--- a/clang/lib/Rewrite/HTMLRewrite.cpp
+++ b/clang/lib/Rewrite/HTMLRewrite.cpp
@@ -437,6 +437,11 @@ void html::HighlightMacros(Rewriter &R, FileID FID, Preprocessor& PP) {
     // preprocessor directives.
     if (Tok.is(tok::hash) && Tok.isAtStartOfLine())
       continue;
+
+    // If this is a ## token, change its kind to unknown so that repreprocessing
+    // it will not produce an error.
+    if (Tok.is(tok::hashhash))
+      Tok.setKind(tok::unknown);
     
     // If this raw token is an identifier, the raw lexer won't have looked up
     // the corresponding identifier info for it.  Do this now so that it will be
diff --git a/clang/test/Misc/emit-html.c b/clang/test/Misc/emit-html.c
index 1bcab12dbc9..c4a184584bf 100644
--- a/clang/test/Misc/emit-html.c
+++ b/clang/test/Misc/emit-html.c
@@ -3,3 +3,9 @@
 // rdar://6562329
 #line 42 "foo.c"
 
+// PR3635
+#define F(fmt, ...) fmt, ## __VA_ARGS__
+int main(int argc, char **argv) {
+  return F(argc, 1);
+}
+