// RUN: %clangxx_asan -O0 -mllvm -asan-instrument-allocas %s -o %t // RUN: %run %t 2>&1 // // REQUIRES: stable-runtime // This testcase checks correct interaction between VLAs and allocas. #include <assert.h> #include <stdint.h> #include <stdlib.h> #include "sanitizer/asan_interface.h" // MSVC provides _alloca instead of alloca. #if defined(_MSC_VER) && !defined(alloca) # define alloca _alloca #endif #define RZ 32 __attribute__((noinline)) void foo(int len) { char *top, *bot; // This alloca call should live until the end of foo. char *alloca1 = (char *)alloca(len); assert(!(reinterpret_cast<uintptr_t>(alloca1) & 31L)); // This should be first poisoned address after loop. top = alloca1 - RZ; for (int i = 0; i < 32; ++i) { // Check that previous alloca was unpoisoned at the end of iteration. if (i) assert(!__asan_region_is_poisoned(bot, 96)); // VLA is unpoisoned at the end of iteration. volatile char array[i]; assert(!(reinterpret_cast<uintptr_t>(array) & 31L)); // Alloca is unpoisoned at the end of iteration, // because dominated by VLA. bot = (char *)alloca(i) - RZ; } // Check that all allocas from loop were unpoisoned correctly. void *q = __asan_region_is_poisoned(bot, (char *)top - (char *)bot + 1); assert(q == top); } int main(int argc, char **argv) { foo(32); return 0; }