kc3-lang/angle/src/compiler/preprocessor/numeric_lex.h

Branch : - branch - main - tag -

• Show log

  Commit

• Author : Geoff Lang
  Date : 2018-02-26 11:55:34
  Hash : 98d0a2b1
  Message : Use strtod instead of istringstream+locale for parsing floats. BUG=803034 Change-Id: I69ca7a86e1841e86c6a8cf6a0b7279a8e42b0012 Reviewed-on: https://chromium-review.googlesource.com/937964 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

• src/compiler/preprocessor/numeric_lex.h

• //
  // Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  // numeric_lex.h: Functions to extract numeric values from string.
  
  #ifndef COMPILER_PREPROCESSOR_NUMERICLEX_H_
  #define COMPILER_PREPROCESSOR_NUMERICLEX_H_
  
  #include <cmath>
  #include <sstream>
  
  namespace pp
  {
  
  inline std::ios::fmtflags numeric_base_int(const std::string &str)
  {
      if ((str.size() >= 2) && (str[0] == '0') && (str[1] == 'x' || str[1] == 'X'))
      {
          return std::ios::hex;
      }
      if ((str.size() >= 1) && (str[0] == '0'))
      {
          return std::ios::oct;
      }
      return std::ios::dec;
  }
  
  // The following functions parse the given string to extract a numerical
  // value of the given type. These functions assume that the string is
  // of the correct form. They can only fail if the parsed value is too big,
  // in which case false is returned.
  
  template <typename IntType>
  bool numeric_lex_int(const std::string &str, IntType *value)
  {
      std::istringstream stream(str);
      // This should not be necessary, but MSVS has a buggy implementation.
      // It returns incorrect results if the base is not specified.
      stream.setf(numeric_base_int(str), std::ios::basefield);
  
      stream >> (*value);
      return !stream.fail();
  }
  
  template <typename FloatType>
  bool numeric_lex_float(const std::string &str, FloatType *value)
  {
      // Some platforms have issues with the usage of std::locale and std::stringstream and cause
      // crashes. Usage of strtod appears to be safe.
      *value = static_cast<FloatType>(strtod(str.c_str(), nullptr));
      return errno != ERANGE && std::isfinite(*value);
  }
  
  }  // namespace pp.
  
  #endif  // COMPILER_PREPROCESSOR_NUMERICLEX_H_