path: root/lib/AsmParser/LLLexer.cpp

//===- LLLexer.cpp - Lexer for .ll Files ----------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implement the Lexer for .ll files.
//
//===----------------------------------------------------------------------===//

#include "LLLexer.h"
#include "ParserInternals.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/MathExtras.h"

#include <list>
#include "llvmAsmParser.h"
using namespace llvm;

//===----------------------------------------------------------------------===//
// Helper functions.
//===----------------------------------------------------------------------===//

// atoull - Convert an ascii string of decimal digits into the unsigned long
// long representation... this does not have to do input error checking,
// because we know that the input will be matched by a suitable regex...
//
static uint64_t atoull(const char *Buffer, const char *End) {
  uint64_t Result = 0;
  for (; Buffer != End; Buffer++) {
    uint64_t OldRes = Result;
    Result *= 10;
    Result += *Buffer-'0';
    if (Result < OldRes) {  // Uh, oh, overflow detected!!!
      GenerateError("constant bigger than 64 bits detected!");
      return 0;
    }
  }
  return Result;
}

static uint64_t HexIntToVal(const char *Buffer, const char *End) {
  uint64_t Result = 0;
  for (; Buffer != End; ++Buffer) {
    uint64_t OldRes = Result;
    Result *= 16;
    char C = *Buffer;
    if (C >= '0' && C <= '9')
      Result += C-'0';
    else if (C >= 'A' && C <= 'F')
      Result += C-'A'+10;
    else if (C >= 'a' && C <= 'f')
      Result += C-'a'+10;
    
    if (Result < OldRes) {   // Uh, oh, overflow detected!!!
      GenerateError("constant bigger than 64 bits detected!");
      return 0;
    }
  }
  return Result;
}

// HexToFP - Convert the ascii string in hexadecimal format to the floating
// point representation of it.
//
static double HexToFP(const char *Buffer, const char *End) {
  return BitsToDouble(HexIntToVal(Buffer, End)); // Cast Hex constant to double
}

static void HexToIntPair(const char *Buffer, const char *End, uint64_t Pair[2]){
  Pair[0] = 0;
  for (int i=0; i<16; i++, Buffer++) {
    assert(Buffer != End);
    Pair[0] *= 16;
    char C = *Buffer;
    if (C >= '0' && C <= '9')
      Pair[0] += C-'0';
    else if (C >= 'A' && C <= 'F')
      Pair[0] += C-'A'+10;
    else if (C >= 'a' && C <= 'f')
      Pair[0] += C-'a'+10;
  }
  Pair[1] = 0;
  for (int i=0; i<16 && Buffer != End; i++, Buffer++) {
    Pair[1] *= 16;
    char C = *Buffer;
    if (C >= '0' && C <= '9')
      Pair[1] += C-'0';
    else if (C >= 'A' && C <= 'F')
      Pair[1] += C-'A'+10;
    else if (C >= 'a' && C <= 'f')
      Pair[1] += C-'a'+10;
  }
  if (Buffer != End)
    GenerateError("constant bigger than 128 bits detected!");
}

// UnEscapeLexed - Run through the specified buffer and change \xx codes to the
// appropriate character.
static void UnEscapeLexed(std::string &Str) {
  if (Str.empty()) return;
  
  char *Buffer = &Str[0], *EndBuffer = Buffer+Str.size();
  char *BOut = Buffer;
  for (char *BIn = Buffer; BIn != EndBuffer; ) {
    if (BIn[0] == '\\') {
      if (BIn < EndBuffer-1 && BIn[1] == '\\') {
        *BOut++ = '\\'; // Two \ becomes one
        BIn += 2;
      } else if (BIn < EndBuffer-2 && isxdigit(BIn[1]) && isxdigit(BIn[2])) {
        char Tmp = BIn[3]; BIn[3] = 0;      // Terminate string
        *BOut = (char)strtol(BIn+1, 0, 16); // Convert to number
        BIn[3] = Tmp;