| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/base/SkSafeMath.h" |
| #include "tests/Test.h" |
| |
| #include <cstddef> |
| #include <limits> |
| |
| DEF_TEST(SafeMath, r) { |
| size_t max = std::numeric_limits<size_t>::max(); |
| |
| { |
| size_t halfMax = max >> 1; |
| size_t halfMaxPlus1 = halfMax + 1; |
| SkSafeMath safe; |
| REPORTER_ASSERT(r, safe.add(halfMax, halfMax) == 2 * halfMax); |
| REPORTER_ASSERT(r, safe); |
| REPORTER_ASSERT(r, safe.add(halfMax, halfMaxPlus1) == max); |
| REPORTER_ASSERT(r, safe); |
| REPORTER_ASSERT(r, safe.add(max, 1) == 0); |
| REPORTER_ASSERT(r, !safe); |
| } |
| |
| { |
| SkSafeMath safe; |
| (void) safe.add(max, max); |
| REPORTER_ASSERT(r, !safe); |
| } |
| |
| { |
| size_t bits = (sizeof(size_t) * 8); |
| size_t halfBits = bits / 2; |
| size_t sqrtMax = max >> halfBits; |
| size_t sqrtMaxPlus1 = sqrtMax + 1; |
| SkSafeMath safe; |
| REPORTER_ASSERT(r, safe.mul(sqrtMax, sqrtMax) == sqrtMax * sqrtMax); |
| REPORTER_ASSERT(r, safe); |
| REPORTER_ASSERT(r, safe.mul(sqrtMax, sqrtMaxPlus1) == sqrtMax << halfBits); |
| REPORTER_ASSERT(r, safe); |
| REPORTER_ASSERT(r, safe.mul(sqrtMaxPlus1, sqrtMaxPlus1) == 0); |
| REPORTER_ASSERT(r, !safe); |
| } |
| |
| { |
| SkSafeMath safe; |
| (void) safe.mul(max, max); |
| REPORTER_ASSERT(r, !safe); |
| } |
| } |