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133 lines
3.8 KiB
133 lines
3.8 KiB
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*/
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#include <iostream>
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namespace condtemp {
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// keep track of how many copies are made of the object and how many
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// of these copies have been destroyed
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struct Counter {
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std::string name;
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int copies;
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int copies_destroyed;
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bool destroyed;
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Counter(std::string name_)
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: name(name_), copies(0), copies_destroyed(0), destroyed(false) {}
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};
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struct X {
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int f; // some data
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Counter* counter; // nullptr if this object is a copy from another X
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Counter* original_counter; // nullptr if this object was created not from a
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// copy or move constructor
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X() = delete;
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X(Counter* counter_) : counter(counter_), original_counter(nullptr), f(72) {
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// std::cerr << "original: " << name() << "\n";
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}
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X(X& x) {
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std::cerr << "copy (of " << x.name()
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<< ") constructor called with f=" << x.f << "\n";
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f = x.f + 11;
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copy_from(x);
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}
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X(X&& x) {
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std::cerr << "move (of " << x.name()
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<< ") constructor called with f=" << x.f << "\n";
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f = x.f + 10;
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copy_from(x);
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}
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~X() {
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std::cerr << "~X(" << f << ") " << name();
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if (original_counter) {
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original_counter->copies_destroyed++;
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}
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if (counter) {
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std::cerr << " original destroyed";
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counter->destroyed = true;
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}
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std::cerr << " \n";
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;
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}
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private:
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void copy_from(X& x) {
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counter = nullptr;
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if (x.counter) {
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original_counter = x.counter;
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} else {
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original_counter = x.original_counter;
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}
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original_counter->copies++;
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}
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std::string& name() {
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if (counter) {
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return counter->name;
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} else {
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return original_counter->name;
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}
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}
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};
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X copy(X x) {
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std::cerr << "copy(" << x.f << ")\n";
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return x;
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}
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void crash(bool b) {
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if (b) {
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}
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}
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void FP_track_copy_operations_one_copy_ok() {
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Counter c_true("c_true"), c_false("c_false");
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X y(&c_false);
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X x = false ? X(&c_true) : y;
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std::cerr << "c_false.copies=" << c_false.copies << "\n";
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std::cerr << "c_false.copies_destroyed=" << c_false.copies_destroyed << "\n";
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std::cerr << "c_false.destroyed=" << c_false.destroyed << "\n";
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std::cerr << "c_true.copies=" << c_true.copies << "\n";
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std::cerr << "c_true.copies_destroyed=" << c_true.copies_destroyed << "\n";
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std::cerr << "c_true.destroyed=" << c_true.destroyed << "\n";
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// these values were checked against the output of the program
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// compiled with clang -fno-elide-constructors, results will vary
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// if we omit the elidable constructor calls
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if (!(c_false.copies == 2 && c_false.copies_destroyed == 1 &&
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!c_false.destroyed) ||
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c_true.copies != 0 || c_true.copies_destroyed != 0 || c_true.destroyed) {
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int* p = nullptr;
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*p = 42;
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}
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}
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void FP_track_copy_operations_complex_ok() {
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Counter c_true("c_true"), c_false("c_false");
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X y(&c_false);
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X x = true ? copy(X(&c_true)) : y;
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std::cerr << "c_false.copies=" << c_false.copies << "\n";
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std::cerr << "c_false.copies_destroyed=" << c_false.copies_destroyed << "\n";
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std::cerr << "c_false.destroyed=" << c_false.destroyed << "\n";
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std::cerr << "c_true.copies=" << c_true.copies << "\n";
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std::cerr << "c_true.copies_destroyed=" << c_true.copies_destroyed << "\n";
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std::cerr << "c_true.destroyed=" << c_true.destroyed << "\n";
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// these values were checked against the output of the program
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// compiled with clang -fno-elide-constructors, results will vary
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// if we omit the elidable constructor calls
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if (!(c_true.copies == 4 && c_true.copies_destroyed == 3 &&
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c_true.destroyed)) {
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int* p = nullptr;
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*p = 42;
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}
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}
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} // namespace condtemp
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int main() { condtemp::FP_track_copy_operations_complex_ok(); }
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