1 files changed, 22 insertions, 1 deletions
diff --git a/lib/MC/MCParser/AsmLexer.cpp b/lib/MC/MCParser/AsmLexer.cpp
index bbb0bbc8b2..9760e4676d 100644
--- a/lib/MC/MCParser/AsmLexer.cpp
+++ b/lib/MC/MCParser/AsmLexer.cpp
@@ -334,6 +334,17 @@ StringRef AsmLexer::LexUntilEndOfStatement() {
   return StringRef(TokStart, CurPtr-TokStart);
 }
 
+StringRef AsmLexer::LexUntilEndOfLine() {
+  TokStart = CurPtr;
+
+  while (*CurPtr != '\n' &&
+         *CurPtr != '\r' &&
+         (*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd())) {
+    ++CurPtr;
+  }
+  return StringRef(TokStart, CurPtr-TokStart);
+}
+
 bool AsmLexer::isAtStartOfComment(char Char) {
   // FIXME: This won't work for multi-character comment indicators like "//".
   return Char == *MAI.getCommentString();
@@ -345,17 +356,26 @@ bool AsmLexer::isAtStatementSeparator(const char *Ptr) {
 }
 
 AsmToken AsmLexer::LexToken() {
+  static bool isAtStartOfLine = true;
   TokStart = CurPtr;
   // This always consumes at least one character.
   int CurChar = getNextChar();
 
-  if (isAtStartOfComment(CurChar))
+  if (isAtStartOfComment(CurChar)) {
+    // If this comment starts with a '#', then return the Hash token and let
+    // the assembler parser see if it can be parsed as a cpp line filename
+    // comment. We do this only if we are at the start of a line.
+    if (CurChar == '#' && isAtStartOfLine)
+      return AsmToken(AsmToken::Hash, StringRef(TokStart, 1));
+    isAtStartOfLine = true;
     return LexLineComment();
+  }
   if (isAtStatementSeparator(TokStart)) {
     CurPtr += strlen(MAI.getSeparatorString()) - 1;
     return AsmToken(AsmToken::EndOfStatement,
                     StringRef(TokStart, strlen(MAI.getSeparatorString())));
   }
+  isAtStartOfLine = false;
 
   switch (CurChar) {
   default:
@@ -373,6 +393,7 @@ AsmToken AsmLexer::LexToken() {
     return LexToken();
   case '\n': // FALL THROUGH.
   case '\r':
+    isAtStartOfLine = true;
     return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
   case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
   case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));