From 26f3bb997f0c5d7951d61d28a26ca6ac1481090c Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Fri, 3 May 2013 00:15:41 +0000
Subject: In MC asm parsing, account for the possibility of whitespace within
 the "identifier" parsed by the frontend callback by skipping forward until
 we've consumed a token that ends at the point dictated by the callback.

In addition, inform the callback when it's parsing an unevaluated
operand (e.g. mov eax, LENGTH A::x) as opposed to an evaluated one
(e.g. mov eax, [A::x]).

This commit depends on a clang commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180978 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/MC/MCParser/MCAsmParser.h    |  3 ++-
 lib/Target/X86/AsmParser/X86AsmParser.cpp | 40 +++++++++++++++++--------------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/include/llvm/MC/MCParser/MCAsmParser.h b/include/llvm/MC/MCParser/MCAsmParser.h
index 4ca5b9ae9e..7f012c65b0 100644
--- a/include/llvm/MC/MCParser/MCAsmParser.h
+++ b/include/llvm/MC/MCParser/MCAsmParser.h
@@ -49,7 +49,8 @@ public:
 
   virtual ~MCAsmParserSemaCallback(); 
   virtual void *LookupInlineAsmIdentifier(StringRef &LineBuf,
-                                          InlineAsmIdentifierInfo &Info) = 0;
+                                          InlineAsmIdentifierInfo &Info,
+                                          bool IsUnevaluatedContext) = 0;
 
   virtual bool LookupInlineAsmField(StringRef Base, StringRef Member,
                                     unsigned &Offset) = 0;
diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index fef5cfe621..5c09434854 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -500,7 +500,8 @@ private:
   X86Operand *ParseIntelBracExpression(unsigned SegReg, SMLoc Start,
                                        int64_t ImmDisp, unsigned Size);
   X86Operand *ParseIntelIdentifier(const MCExpr *&Val, StringRef &Identifier,
-                                   InlineAsmIdentifierInfo &Info, SMLoc &End);
+                                   InlineAsmIdentifierInfo &Info,
+                                   bool IsUnevaluatedOperand, SMLoc &End);
 
   X86Operand *ParseMemOperand(unsigned SegReg, SMLoc StartLoc);
 
@@ -1267,7 +1268,8 @@ X86AsmParser::ParseIntelExpression(IntelExprStateMachine &SM, SMLoc &End) {
             return ErrorOperand(Tok.getLoc(), "Unexpected identifier!");
         } else {
           InlineAsmIdentifierInfo &Info = SM.getIdentifierInfo();
-          if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info, End))
+          if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info,
+                                                     /*Unevaluated*/ false, End))
             return Err;
         }
         SM.onIdentifierExpr(Val, Identifier);
@@ -1367,27 +1369,26 @@ X86Operand *X86AsmParser::ParseIntelBracExpression(unsigned SegReg, SMLoc Start,
 X86Operand *X86AsmParser::ParseIntelIdentifier(const MCExpr *&Val,
                                                StringRef &Identifier,
                                                InlineAsmIdentifierInfo &Info,
+                                               bool IsUnevaluatedOperand,
                                                SMLoc &End) {
   assert (isParsingInlineAsm() && "Expected to be parsing inline assembly.");
   Val = 0;
 
   StringRef LineBuf(Identifier.data());
-  SemaCallback->LookupInlineAsmIdentifier(LineBuf, Info);
-  unsigned BufLen = LineBuf.size();
-  assert (BufLen && "Expected a non-zero length identifier.");
+  SemaCallback->LookupInlineAsmIdentifier(LineBuf, Info, IsUnevaluatedOperand);
 
-  // Advance the token stream based on what the frontend parsed.
   const AsmToken &Tok = Parser.getTok();
-  AsmToken IdentEnd = Tok;
-  while (BufLen > 0) {
-    IdentEnd = Tok;
-    BufLen -= Tok.getString().size();
-    getLexer().Lex(); // Consume the token.
+
+  // Advance the token stream until the end of the current token is
+  // after the end of what the frontend claimed.
+  const char *EndPtr = Tok.getLoc().getPointer() + LineBuf.size();
+  while (true) {
+    End = Tok.getEndLoc();
+    getLexer().Lex();
+
+    assert(End.getPointer() <= EndPtr && "frontend claimed part of a token?");
+    if (End.getPointer() == EndPtr) break;
   }
-  if (BufLen != 0)
-    return ErrorOperand(IdentEnd.getLoc(),
-                        "Frontend parser mismatch with asm lexer!");
-  End = IdentEnd.getEndLoc();
 
   // Create the symbol reference.
   Identifier = LineBuf;
@@ -1447,7 +1448,8 @@ X86Operand *X86AsmParser::ParseIntelMemOperand(unsigned SegReg,
 
   InlineAsmIdentifierInfo Info;
   StringRef Identifier = Tok.getString();
-  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info, End))
+  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info,
+                                             /*Unevaluated*/ false, End))
     return Err;
   return CreateMemForInlineAsm(/*SegReg=*/0, Val, /*BaseReg=*/0,/*IndexReg=*/0,
                                /*Scale=*/1, Start, End, Size, Identifier, Info);
@@ -1506,7 +1508,8 @@ X86Operand *X86AsmParser::ParseIntelOffsetOfOperator() {
   InlineAsmIdentifierInfo Info;
   SMLoc Start = Tok.getLoc(), End;
   StringRef Identifier = Tok.getString();
-  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info, End))
+  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info,
+                                             /*Unevaluated*/ false, End))
     return Err;
 
   // Don't emit the offset operator.
@@ -1541,7 +1544,8 @@ X86Operand *X86AsmParser::ParseIntelOperator(unsigned OpKind) {
   InlineAsmIdentifierInfo Info;
   SMLoc Start = Tok.getLoc(), End;
   StringRef Identifier = Tok.getString();
-  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info, End))
+  if (X86Operand *Err = ParseIntelIdentifier(Val, Identifier, Info,
+                                             /*Unevaluated*/ true, End))
     return Err;
 
   unsigned CVal = 0;
-- 
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