[MC] Fix Error Location for ParseIdentifier

Prevent partial parsing of '$' or '@' of invalid identifiers and fixup
workaround points. NFC Intended.

llvm-svn: 284017

1 files changed, 11 insertions, 4 deletions

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index f4de6343660..e817a8fa57d 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -924,8 +924,10 @@ bool AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
   case AsmToken::Identifier: {
     StringRef Identifier;
     if (parseIdentifier(Identifier)) {
-      if (FirstTokenKind == AsmToken::Dollar) {
+      // We may have failed but $ may be a valid token.
+      if (getTok().is(AsmToken::Dollar)) {
         if (Lexer.getMAI().getDollarIsPC()) {
+          Lex();
           // This is a '$' reference, which references the current PC.  Emit a
           // temporary label to the streamer and refer to it.
           MCSymbol *Sym = Ctx.createTempSymbol();
@@ -2607,14 +2609,19 @@ bool AsmParser::parseIdentifier(StringRef &Res) {
     SMLoc PrefixLoc = getLexer().getLoc();
 
     // Consume the prefix character, and check for a following identifier.
-    Lexer.Lex(); // Lexer's Lex guarantees consecutive token.
-    if (Lexer.isNot(AsmToken::Identifier))
+
+    AsmToken Buf[1];
+    Lexer.peekTokens(Buf, false);
+
+    if (Buf[0].isNot(AsmToken::Identifier))
       return true;
 
     // We have a '$' or '@' followed by an identifier, make sure they are adjacent.
-    if (PrefixLoc.getPointer() + 1 != getTok().getLoc().getPointer())
+    if (PrefixLoc.getPointer() + 1 != Buf[0].getLoc().getPointer())
       return true;
 
+    // eat $ or @
+    Lexer.Lex(); // Lexer's Lex guarantees consecutive token.
     // Construct the joined identifier and consume the token.
     Res =
         StringRef(PrefixLoc.getPointer(), getTok().getIdentifier().size() + 1);