// Marks memory region [addr, addr+size) as unaddressable.
// This memory must be previously allocated by the user program. Accessing
// addresses in this region from instrumented code is forbidden until
// this region is unpoisoned. This function is not guaranteed to poison
// the whole region - it may poison only subregion of [addr, addr+size) due
// to ASan alignment restrictions.
// Method is NOT thread-safe in the sense that no two threads can
// (un)poison memory in the same memory region simultaneously.
void __asan_poison_memory_region(void const volatile *addr, size_t size);
// Marks memory region [addr, addr+size) as addressable.
// This memory must be previously allocated by the user program. Accessing
// addresses in this region is allowed until this region is poisoned again.
// This function may unpoison a superregion of [addr, addr+size) due to
// ASan alignment restrictions.
// Method is NOT thread-safe in the sense that no two threads can
// (un)poison memory in the same memory region simultaneously.
void __asan_unpoison_memory_region(void const volatile *addr, size_t size);

// User code should use macros instead of functions.
#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
#define ASAN_POISON_MEMORY_REGION(addr, size) \
                                                __asan_poison_memory_region((addr), (size))
#define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
    __asan_unpoison_memory_region((addr), (size))
#else
#define ASAN_POISON_MEMORY_REGION(addr, size) \
    ((void)(addr), (void)(size))
#define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
    ((void)(addr), (void)(size))
#endif