// RUN: clang -O -g -fsanitize=address %t && ./a.out// By default, AddressSanitizer does not try to detect// stack-use-after-return bugs.// It may still find such bugs occasionally// and report them as a hard-to-explain stack-buffer-overflow.// You need to run the test with ASAN_OPTIONS=detect_stack_use_after_return=1int *ptr;__attribute__((noinline))void FunctionThatEscapesLocalObject() {  int local[100];  ptr = &local[0];}int main(int argc, char **argv) {  FunctionThatEscapesLocalObject();  return ptr[argc];}

===================================================================6268== ERROR: AddressSanitizer: stack-use-after-return on address 0x7fa19a8fc024 at pc 0x4180d5 bp 0x7fff73c3fc50 sp 0x7fff73c3fc48READ of size 4 at 0x7fa19a8fc024 thread T0    #0 0x4180d4 in main example_UseAfterReturn.cc:17    #1 0x7fa19b11d76c (/lib/x86_64-linux-gnu/libc.so.6+0x2176c)    #2 0x417f34 (a.out+0x417f34)Address 0x7fa19a8fc024 is located at offset 36 in frame <_Z30FunctionThatEscapesLocalObjectv> of T0's stack:  This frame has 1 object(s):    [32, 432) 'local'HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext      (longjmp and C++ exceptions *are* supported)Shadow bytes around the buggy address:  0x1ff43351f7b0: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe  0x1ff43351f7c0: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe  0x1ff43351f7d0: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe  0x1ff43351f7e0: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe  0x1ff43351f7f0: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe=>0x1ff43351f800: f5 f5 f5 f5[f5]f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5  0x1ff43351f810: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5  0x1ff43351f820: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5  0x1ff43351f830: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 00 00 00 00  0x1ff43351f840: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  0x1ff43351f850: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00Shadow byte legend (one shadow byte represents 8 application bytes):  Addressable:           00  Partially addressable: 01 02 03 04 05 06 07   Heap left redzone:     fa  Heap righ redzone:     fb  Freed Heap region:     fd  Stack left redzone:    f1  Stack mid redzone:     f2  Stack right redzone:   f3  Stack partial redzone: f4  Stack after return:    f5  Stack use after scope: f8  Global redzone:        f9  Global init order:     f6  Poisoned by user:      f7  ASan internal:         fe==6268== ABORTING