path: root/tools/llvm-mc/AsmParser.cpp

//===- AsmParser.cpp - Parser for Assembly Files --------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements the parser for assembly files.
//
//===----------------------------------------------------------------------===//

#include "AsmParser.h"

#include "AsmExpr.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;

void AsmParser::Warning(SMLoc L, const char *Msg) {
  Lexer.PrintMessage(L, Msg, "warning");
}

bool AsmParser::Error(SMLoc L, const char *Msg) {
  Lexer.PrintMessage(L, Msg, "error");
  return true;
}

bool AsmParser::TokError(const char *Msg) {
  Lexer.PrintMessage(Lexer.getLoc(), Msg, "error");
  return true;
}

bool AsmParser::Run() {
  // Prime the lexer.
  Lexer.Lex();
  
  bool HadError = false;
  
  // While we have input, parse each statement.
  while (Lexer.isNot(asmtok::Eof)) {
    if (!ParseStatement()) continue;
  
    // If we had an error, remember it and recover by skipping to the next line.
    HadError = true;
    EatToEndOfStatement();
  }
  
  return HadError;
}

/// EatToEndOfStatement - Throw away the rest of the line for testing purposes.
void AsmParser::EatToEndOfStatement() {
  while (Lexer.isNot(asmtok::EndOfStatement) &&
         Lexer.isNot(asmtok::Eof))
    Lexer.Lex();
  
  // Eat EOL.
  if (Lexer.is(asmtok::EndOfStatement))
    Lexer.Lex();
}


/// ParseParenExpr - Parse a paren expression and return it.
/// NOTE: This assumes the leading '(' has already been consumed.
///
/// parenexpr ::= expr)
///
bool AsmParser::ParseParenExpr(AsmExpr *&Res) {
  if (ParseExpression(Res)) return true;
  if (Lexer.isNot(asmtok::RParen))
    return TokError("expected ')' in parentheses expression");
  Lexer.Lex();
  return false;
}

/// ParsePrimaryExpr - Parse a primary expression and return it.
///  primaryexpr ::= (parenexpr
///  primaryexpr ::= symbol
///  primaryexpr ::= number
///  primaryexpr ::= ~,+,- primaryexpr
bool AsmParser::ParsePrimaryExpr(AsmExpr *&Res) {
  switch (Lexer.getKind()) {
  default:
    return TokError("unknown token in expression");
  case asmtok::Exclaim:
    Lexer.Lex(); // Eat the operator.
    if (ParsePrimaryExpr(Res))
      return true;
    Res = new AsmUnaryExpr(AsmUnaryExpr::LNot, Res);
    return false;
  case asmtok::Identifier: {
    // This is a label, this should be parsed as part of an expression, to
    // handle things like LFOO+4.
    MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal());

    // If this is use of an undefined symbol then mark it external.
    if (!Sym->getSection() && !