text: //===-- MCAsmParser.cpp - Abstract Asm Parser Interface -------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/MC/MCParser/MCAsmParser.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/ADT/Twine.h"
  #include "llvm/Config/llvm-config.h"
  #include "llvm/MC/MCParser/MCAsmLexer.h"
  #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
  #include "llvm/MC/MCParser/MCTargetAsmParser.h"
  #include "llvm/Support/Debug.h"
  #include "llvm/Support/SMLoc.h"
  #include "llvm/Support/raw_ostream.h"
  #include <cassert>
  
  using namespace llvm;
  
  MCAsmParser::MCAsmParser() : ShowParsedOperands(0) {}
  
  MCAsmParser::~MCAsmParser() = default;
  
  void MCAsmParser::setTargetParser(MCTargetAsmParser &P) {
    assert(!TargetParser && "Target parser is already initialized!");
    TargetParser = &P;
    TargetParser->Initialize(*this);
  }
  
  const AsmToken &MCAsmParser::getTok() const {
    return getLexer().getTok();
  }
  
  bool MCAsmParser::parseTokenLoc(SMLoc &Loc) {
    Loc = getTok().getLoc();
    return false;
  }
  
  bool MCAsmParser::parseEOL(const Twine &Msg) {
    if (getTok().getKind() != AsmToken::EndOfStatement)
      return Error(getTok().getLoc(), Msg);
    Lex();
    return false;
  }
  
  bool MCAsmParser::parseToken(AsmToken::TokenKind T, const Twine &Msg) {
    if (T == AsmToken::EndOfStatement)
      return parseEOL(Msg);
    if (getTok().getKind() != T)
      return Error(getTok().getLoc(), Msg);
    Lex();
    return false;
  }
  
  bool MCAsmParser::parseIntToken(int64_t &V, const Twine &Msg) {
    if (getTok().getKind() != AsmToken::Integer)
      return TokError(Msg);
    V = getTok().getIntVal();
    Lex();
    return false;
  }
  
  bool MCAsmParser::parseOptionalToken(AsmToken::TokenKind T) {
    bool Present = (getTok().getKind() == T);
    if (Present)
      parseToken(T);
    return Present;
  }
  
  bool MCAsmParser::check(bool P, const Twine &Msg) {
    return check(P, getTok().getLoc(), Msg);
  }
  
  bool MCAsmParser::check(bool P, SMLoc Loc, const Twine &Msg) {
    if (P)
      return Error(Loc, Msg);
    return false;
  }
  
  bool MCAsmParser::TokError(const Twine &Msg, SMRange Range) {
    return Error(getLexer().getLoc(), Msg, Range);
  }
  
  bool MCAsmParser::Error(SMLoc L, const Twine &Msg, SMRange Range) {
  
    MCPendingError PErr;
    PErr.Loc = L;
    Msg.toVector(PErr.Msg);
    PErr.Range = Range;
    PendingErrors.push_back(PErr);
  
    // If we threw this parsing error after a lexing error, this should
    // supercede the lexing error and so we remove it from the Lexer
    // before it can propagate
    if (getTok().is(AsmToken::Error))
      getLexer().Lex();
    return true;
  }
  
  bool MCAsmParser::addErrorSuffix(const Twine &Suffix) {
    // Make sure lexing errors have propagated to the parser.
    if (getTok().is(AsmToken::Error))
      Lex();
    for (auto &PErr : PendingErrors)
      Suffix.toVector(PErr.Msg);
    return true;
  }
  
  bool MCAsmParser::parseMany(function_ref<bool()> parseOne, bool hasComma) {
    if (parseOptionalToken(AsmToken::EndOfStatement))
      return false;
    while (true) {
      if (parseOne())
        return true;
      if (parseOptionalToken(AsmToken::EndOfStatement))
        return false;
      if (hasComma && parseToken(AsmToken::Comma))
        return true;
    }
    return false;
  }
  
  bool MCAsmParser::parseExpression(const MCExpr *&Res) {
    SMLoc L;
    return parseExpression(Res, L);
  }
  
  void MCParsedAsmOperand::dump() const {
    // Cannot completely remove virtual function even in release mode.
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
    dbgs() << "  " << *this;
  #endif
  }
  