blob: 56973439d953e6593b7991fc6ee96fce8d18372f [file] [log] [blame]
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <google/protobuf/io/strtod.h>
#include <cstdio>
#include <cstring>
#include <string>
#include <google/protobuf/stubs/common.h>
namespace google {
namespace protobuf {
namespace io {
// ----------------------------------------------------------------------
// NoLocaleStrtod()
// This code will make you cry.
// ----------------------------------------------------------------------
namespace {
// Returns a string identical to *input except that the character pointed to
// by radix_pos (which should be '.') is replaced with the locale-specific
// radix character.
string LocalizeRadix(const char* input, const char* radix_pos) {
// Determine the locale-specific radix character by calling sprintf() to
// print the number 1.5, then stripping off the digits. As far as I can
// tell, this is the only portable, thread-safe way to get the C library
// to divuldge the locale's radix character. No, localeconv() is NOT
// thread-safe.
char temp[16];
int size = sprintf(temp, "%.1f", 1.5);
GOOGLE_CHECK_EQ(temp[0], '1');
GOOGLE_CHECK_EQ(temp[size-1], '5');
GOOGLE_CHECK_LE(size, 6);
// Now replace the '.' in the input with it.
string result;
result.reserve(strlen(input) + size - 3);
result.append(input, radix_pos);
result.append(temp + 1, size - 2);
result.append(radix_pos + 1);
return result;
}
} // namespace
double NoLocaleStrtod(const char* text, char** original_endptr) {
// We cannot simply set the locale to "C" temporarily with setlocale()
// as this is not thread-safe. Instead, we try to parse in the current
// locale first. If parsing stops at a '.' character, then this is a
// pretty good hint that we're actually in some other locale in which
// '.' is not the radix character.
char* temp_endptr;
double result = strtod(text, &temp_endptr);
if (original_endptr != NULL) *original_endptr = temp_endptr;
if (*temp_endptr != '.') return result;
// Parsing halted on a '.'. Perhaps we're in a different locale? Let's
// try to replace the '.' with a locale-specific radix character and
// try again.
string localized = LocalizeRadix(text, temp_endptr);
const char* localized_cstr = localized.c_str();
char* localized_endptr;
result = strtod(localized_cstr, &localized_endptr);
if ((localized_endptr - localized_cstr) >
(temp_endptr - text)) {
// This attempt got further, so replacing the decimal must have helped.
// Update original_endptr to point at the right location.
if (original_endptr != NULL) {
// size_diff is non-zero if the localized radix has multiple bytes.
int size_diff = localized.size() - strlen(text);
// const_cast is necessary to match the strtod() interface.
*original_endptr = const_cast<char*>(
text + (localized_endptr - localized_cstr - size_diff));
}
}
return result;
}
} // namespace io
} // namespace protobuf
} // namespace google