toolkit/crashreporter/nsExceptionHandlerUtils.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsExceptionHandlerUtils.h"
   8
   9 #include <algorithm>
  10
  11 #include "double-conversion/double-conversion.h"
  12
  13 // Format a non-negative double to a string, without using C-library functions,
  14 // which need to be avoided (.e.g. bug 1240160, comment 10).  Return false if
  15 // we failed to get the formatting done correctly.
  16 bool SimpleNoCLibDtoA(double aValue, char* aBuffer, int aBufferLength) {
  17   // aBufferLength is the size of the buffer.  Be paranoid.
  18   aBuffer[aBufferLength - 1] = '\0';
  19
  20   if (aValue < 0) {
  21     return false;
  22   }
  23
  24   int length, point, i;
  25   bool sign;
  26   bool ok = true;
  27   double_conversion::DoubleToStringConverter::DoubleToAscii(
  28       aValue, double_conversion::DoubleToStringConverter::SHORTEST, 8, aBuffer,
  29       aBufferLength, &sign, &length, &point);
  30
  31   // length does not account for the 0 terminator.
  32   if (length > point && (length + 1) < (aBufferLength - 1)) {
  33     // We have to insert a decimal point.  Not worried about adding a leading
  34     // zero in the < 1 (point == 0) case.
  35     aBuffer[length + 1] = '\0';
  36     for (i = length; i > std::max(point, 0); i -= 1) {
  37       aBuffer[i] = aBuffer[i - 1];
  38     }
  39     aBuffer[i] = '.';  // Not worried about locales
  40   } else if (length < point) {
  41     // Trailing zeros scenario
  42     for (i = length; i < point; i += 1) {
  43       if (i >= aBufferLength - 2) {
  44         ok = false;
  45       }
  46       aBuffer[i] = '0';
  47     }
  48     aBuffer[i] = '\0';
  49   }
  50   return ok;
  51 }