MS asm: Properly handle quoted symbol names

We would get confused by '@' characters in symbol names, we would
mistake the text following them for the variant kind.

When an identifier a string, the variant kind will never show up inside
of it.  Instead, check to see if there is a variant following the
string.

This fixes PR19965.

llvm-svn: 211249

1 files changed, 13 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 932d0f3318e..1ba02d181db 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -812,7 +812,19 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
     // Parse symbol variant
     std::pair<StringRef, StringRef> Split;
     if (!MAI.useParensForSymbolVariant()) {
-      Split = Identifier.split('@');
+      if (FirstTokenKind == AsmToken::String) {
+        if (Lexer.is(AsmToken::At)) {
+          Lexer.Lex(); // eat @
+          SMLoc AtLoc = getLexer().getLoc();
+          StringRef VName;
+          if (parseIdentifier(VName))
+            return Error(AtLoc, "expected symbol variant after '@'");
+
+          Split = std::make_pair(Identifier, VName);
+        }
+      } else {
+        Split = Identifier.split('@');
+      }
     } else if (Lexer.is(AsmToken::LParen)) {
       Lexer.Lex(); // eat (
       StringRef VName;