57 lines
1.8 KiB
C++
57 lines
1.8 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: c++03, c++11, c++14, c++17
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// UNSUPPORTED: libcpp-no-concepts
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// UNSUPPORTED: libcpp-has-no-incomplete-ranges
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// If we have a copy-propagating cache, when we copy ZeroOnDestroy, we will get a
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// dangling reference to the copied-from object. This test ensures that we do not
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// propagate the cache on copy.
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#include <ranges>
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#include <cstddef>
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#include <cstring>
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#include "test_macros.h"
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#include "types.h"
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struct ZeroOnDestroy : std::ranges::view_base {
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unsigned count = 0;
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int buff[8] = {1, 2, 3, 4, 5, 6, 7, 8};
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constexpr ForwardIter begin() { return ForwardIter(buff); }
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constexpr ForwardIter begin() const { return ForwardIter(); }
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constexpr ForwardIter end() { return ForwardIter(buff + 8); }
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constexpr ForwardIter end() const { return ForwardIter(); }
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~ZeroOnDestroy() {
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memset(buff, 0, sizeof(buff));
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}
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static auto dropFirstFour() {
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ZeroOnDestroy zod;
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std::ranges::drop_view dv(zod, 4);
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// Make sure we call begin here so the next call to begin will
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// use the cached iterator.
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assert(*dv.begin() == 5);
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// Intentionally invoke the copy ctor here.
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return std::ranges::drop_view(dv);
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}
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};
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int main(int, char**) {
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auto noDanlingCache = ZeroOnDestroy::dropFirstFour();
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// If we use the cached version, it will reference the copied-from view.
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// Worst case this is a segfault, best case it's an assertion fired.
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assert(*noDanlingCache.begin() == 5);
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return 0;
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}
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