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geoffw0geoffw0
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Merge pull request github#5541 from MathiasVP/definitions-for-unique_ptr
C++: Add shared_ptr and unique_ptr implementations
2 parents 2dadc75 + 09ba25f commit d2b991b

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‎cpp/ql/test/library-tests/dataflow/smart-pointers-taint/memory.h

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namespace std {
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namespace detail {
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template<typename T>
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class compressed_pair_element {
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T element;
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public:
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compressed_pair_element() = default;
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compressed_pair_element(const T& t) : element(t) {}
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T& get() { return element; }
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const T& get() const { return element; }
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};
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template<typename T, typename U>
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struct compressed_pair : private compressed_pair_element<T>, private compressed_pair_element<U> {
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compressed_pair() = default;
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compressed_pair(T& t) : compressed_pair_element<T>(t), compressed_pair_element<U>() {}
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compressed_pair(const compressed_pair&) = delete;
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compressed_pair(compressed_pair<T, U>&&) noexcept = default;
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T& first() { return static_cast<compressed_pair_element<T>&>(*this).get(); }
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U& second() { return static_cast<compressed_pair_element<U>&>(*this).get(); }
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const T& first() const { return static_cast<const compressed_pair_element<T>&>(*this).get(); }
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const U& second() const { return static_cast<const compressed_pair_element<U>&>(*this).get(); }
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};
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}
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template<class T>
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struct default_delete {
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void operator()(T* ptr) const { delete ptr; }
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};
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template<class T>
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struct default_delete<T[]> {
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template<class U>
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void operator()(U* ptr) const { delete[] ptr; }
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};
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template<class T, class Deleter = default_delete<T> >
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class unique_ptr {
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private:
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detail::compressed_pair<T*, Deleter> data;
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public:
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constexpr unique_ptr() noexcept {}
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explicit unique_ptr(T* ptr) noexcept : data(ptr) {}
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unique_ptr(const unique_ptr& ptr) = delete;
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unique_ptr(unique_ptr&& ptr) noexcept = default;
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unique_ptr& operator=(unique_ptr&& ptr) noexcept = default;
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T& operator*() const { return *get(); }
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T* operator->() const noexcept { return get(); }
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T* get() const noexcept { return data.first(); }
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~unique_ptr() {
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Deleter& d = data.second();
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d(data.first());
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}
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};
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template<typename T, class... Args> unique_ptr<T> make_unique(Args&&... args) {
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return unique_ptr<T>(new T(args...)); // std::forward calls elided for simplicity.
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}
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class ctrl_block {
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unsigned uses;
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public:
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ctrl_block() : uses(1) {}
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void inc() { ++uses; }
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bool dec() { return --uses == 0; }
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virtual void destroy() = 0;
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virtual ~ctrl_block() {}
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};
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template<typename T, class Deleter = default_delete<T> >
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struct ctrl_block_impl: public ctrl_block {
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T* ptr;
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Deleter d;
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ctrl_block_impl(T* ptr, Deleter d) : ptr(ptr), d(d) {}
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virtual void destroy() override { d(ptr); }
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};
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template<class T>
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class shared_ptr {
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private:
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ctrl_block* ctrl;
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T* ptr;
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void dec() {
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if(ctrl->dec()) {
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ctrl->destroy();
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delete ctrl;
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}
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}
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void inc() {
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ctrl->inc();
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}
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public:
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constexpr shared_ptr() noexcept = default;
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shared_ptr(T* ptr) : ctrl(new ctrl_block_impl<T>(ptr, default_delete<T>())) {}
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shared_ptr(const shared_ptr& s) noexcept : ptr(s.ptr), ctrl(s.ctrl) {
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inc();
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}
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shared_ptr(shared_ptr&& s) noexcept = default;
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T* operator->() const { return ptr; }
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T& operator*() const { return *ptr; }
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~shared_ptr() { dec(); }
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};
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template<typename T, class... Args> shared_ptr<T> make_shared(Args&&... args) {
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return shared_ptr<T>(new T(args...)); // std::forward calls elided for simplicity.
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}
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}

‎cpp/ql/test/library-tests/dataflow/smart-pointers-taint/taint.expected

Whitespace-only changes.

‎cpp/ql/test/library-tests/dataflow/smart-pointers-taint/taint.ql

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import TestUtilities.dataflow.FlowTestCommon
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module ASTTest {
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private import semmle.code.cpp.dataflow.TaintTracking
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class ASTSmartPointerTaintConfig extends TaintTracking::Configuration {
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ASTSmartPointerTaintConfig() { this = "ASTSmartPointerTaintConfig" }
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override predicate isSource(DataFlow::Node source) {
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source.asExpr().(FunctionCall).getTarget().getName() = "source"
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}
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override predicate isSink(DataFlow::Node sink) {
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exists(FunctionCall call |
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call.getTarget().getName() = "sink" and
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sink.asExpr() = call.getAnArgument()
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)
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}
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}
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}
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module IRTest {
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private import semmle.code.cpp.ir.dataflow.TaintTracking
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class IRSmartPointerTaintConfig extends TaintTracking::Configuration {
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IRSmartPointerTaintConfig() { this = "IRSmartPointerTaintConfig" }
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override predicate isSource(DataFlow::Node source) {
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source.asExpr().(FunctionCall).getTarget().getName() = "source"
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}
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override predicate isSink(DataFlow::Node sink) {
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exists(FunctionCall call |
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call.getTarget().getName() = "sink" and
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sink.asExpr() = call.getAnArgument()
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)
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}
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}
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}

‎cpp/ql/test/library-tests/dataflow/smart-pointers-taint/test.cpp

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#include "memory.h"
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int source();
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void sink(int);
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void test_unique_ptr_int() {
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std::unique_ptr<int> p1(new int(source()));
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std::unique_ptr<int> p2 = std::make_unique<int>(source());
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sink(*p1); // $ MISSING: ast,ir
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sink(*p2); // $ ast ir=8:50
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}
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struct A {
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int x, y;
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A(int x, int y) : x(x), y(y) {}
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};
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void test_unique_ptr_struct() {
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std::unique_ptr<A> p1(new A{source(), 0});
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std::unique_ptr<A> p2 = std::make_unique<A>(source(), 0);
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sink(p1->x); // $ MISSING: ast,ir
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sink(p1->y);
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sink(p2->x); // $ MISSING: ast,ir
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sink(p2->y);
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}
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void test_shared_ptr_int() {
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std::shared_ptr<int> p1(new int(source()));
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std::shared_ptr<int> p2 = std::make_shared<int>(source());
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sink(*p1); // $ ast
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sink(*p2); // $ ast ir=32:50
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}
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void test_shared_ptr_struct() {
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std::shared_ptr<A> p1(new A{source(), 0});
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std::shared_ptr<A> p2 = std::make_shared<A>(source(), 0);
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sink(p1->x); // $ MISSING: ast,ir
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sink(p1->y);
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sink(p2->x); // $ MISSING: ast,ir
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sink(p2->y);
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}

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