64 lines · cpp
1// RUN: %check_clang_tidy -std=c++20 %s bugprone-bitwise-pointer-cast %t2 3void memcpy(void* to, void* dst, unsigned long long size)4{5 // Dummy implementation for the purpose of the test6}7 8namespace std9{10template <typename To, typename From>11To bit_cast(From from)12{13 // Dummy implementation for the purpose of the test14 To to{};15 return to;16}17 18using ::memcpy;19}20 21void pointer2pointer()22{23 int x{};24 float bad = *std::bit_cast<float*>(&x); // UB, but looks safe due to std::bit_cast25 // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: do not use 'std::bit_cast' to cast between pointers [bugprone-bitwise-pointer-cast]26 float good = std::bit_cast<float>(x); // Well-defined27 28 using IntPtr = int*;29 using FloatPtr = float*;30 IntPtr x2{};31 float bad2 = *std::bit_cast<FloatPtr>(x2);32 // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: do not use 'std::bit_cast' to cast between pointers [bugprone-bitwise-pointer-cast]33}34 35void pointer2pointer_memcpy()36{37 int x{};38 int* px{};39 float y{};40 float* py{};41 42 memcpy(&py, &px, sizeof(px));43 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use 'memcpy' to cast between pointers [bugprone-bitwise-pointer-cast]44 std::memcpy(&py, &px, sizeof(px));45 // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use 'memcpy' to cast between pointers [bugprone-bitwise-pointer-cast]46 47 std::memcpy(&y, &x, sizeof(x));48}49 50// Pointer-integer conversions are allowed by this check51void int2pointer()52{53 unsigned long long addr{};54 float* p = std::bit_cast<float*>(addr);55 std::memcpy(&p, &addr, sizeof(addr));56}57 58void pointer2int()59{60 float* p{};61 auto addr = std::bit_cast<unsigned long long>(p);62 std::memcpy(&addr, &p, sizeof(p));63}64