2685678cd0
This reverts commit acbb7e3243. No longer needed
with safeint.h from recent "Windows Software Development Kit - Windows
10.0.15063.137".
89 lines
2.4 KiB
C++
89 lines
2.4 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*/
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#ifndef INCLUDED_O3TL_SAFEINT_HXX
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#define INCLUDED_O3TL_SAFEINT_HXX
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#include <limits>
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#if defined(_MSC_VER)
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#include <safeint.h>
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#else
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#ifndef __has_builtin
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# define __has_builtin(x) 0
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#endif
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#endif
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namespace o3tl
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{
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#if defined(_MSC_VER)
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template<typename T> inline bool checked_multiply(T a, T b, T& result)
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{
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return !msl::utilities::SafeMultiply(a, b, result);
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}
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#elif (defined __GNUC__ && __GNUC__ >= 5) || (__has_builtin(__builtin_mul_overflow))
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template<typename T> inline bool checked_multiply(T a, T b, T& result)
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{
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return __builtin_mul_overflow(a, b, &result);
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}
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#else
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//https://www.securecoding.cert.org/confluence/display/c/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow
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template<typename T> inline typename std::enable_if<std::is_signed<T>::value, bool>::type checked_multiply(T a, T b, T& result)
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{
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if (a > 0) { /* a is positive */
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if (b > 0) { /* a and b are positive */
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if (a > (std::numeric_limits<T>::max() / b)) {
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return true; /* Handle error */
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}
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} else { /* a positive, b nonpositive */
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if (b < (std::numeric_limits<T>::min() / a)) {
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return true; /* Handle error */
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}
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} /* a positive, b nonpositive */
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} else { /* a is nonpositive */
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if (b > 0) { /* a is nonpositive, b is positive */
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if (a < (std::numeric_limits<T>::min() / b)) {
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return true; /* Handle error */
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}
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} else { /* a and b are nonpositive */
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if ( (a != 0) && (b < (std::numeric_limits<T>::max() / a))) {
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return true; /* Handle error */
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}
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} /* End if a and b are nonpositive */
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} /* End if a is nonpositive */
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result = a * b;
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return false;
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}
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//https://www.securecoding.cert.org/confluence/display/c/INT30-C.+Ensure+that+unsigned+integer+operations+do+not+wrap
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template<typename T> inline typename std::enable_if<std::is_unsigned<T>::value, bool>::type checked_multiply(T a, T b, T& result)
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{
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if (b && a > std::numeric_limits<T>::max() / b) {
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return true;/* Handle error */
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}
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result = a * b;
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return false;
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}
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#endif
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}
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#endif
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/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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