stale_stack_leak.cc revision 86277eb844c4983c81de62d7c050e92fe7155788 
1// Test that out-of-scope local variables are ignored by LSan.
2// RUN: LSAN_BASE="report_objects=1:use_registers=0:use_stacks=1"
3// RUN: %clangxx_lsan %s -o %t
4// RUN: LSAN_OPTIONS=$LSAN_BASE not %run %t 2>&1 | FileCheck %s
5// RUN: LSAN_OPTIONS=$LSAN_BASE":exitcode=0" %run %t 2>&1 | FileCheck --check-prefix=CHECK-sanity %s
6
7#include <stdio.h>
8#include <stdlib.h>
9
10void **pp;
11
12// Put pointer far enough on the stack that LSan has space to run in without
13// overwriting it.
14// Hopefully the argument p will be passed on a register, saving us from false
15// negatives.
16__attribute__((noinline))
17void *PutPointerOnStaleStack(void *p) {
18  void *locals[2048];
19  locals[0] = p;
20  pp = &locals[0];
21  fprintf(stderr, "Test alloc: %p.\n", locals[0]);
22  return 0;
23}
24
25int main() {
26  PutPointerOnStaleStack(malloc(1337));
27  return 0;
28}
29
30// This must run after LSan, to ensure LSan didn't overwrite the pointer before
31// it had a chance to see it. If LSan is invoked with atexit(), this works.
32// Otherwise, we need a different method.
33__attribute__((destructor))
34__attribute__((no_sanitize_address))
35void ConfirmPointerHasSurvived() {
36  fprintf(stderr, "Value after LSan: %p.\n", *pp);
37}
38// CHECK: Test alloc: [[ADDR:.*]].
39// CHECK-sanity: Test alloc: [[ADDR:.*]].
40// CHECK: LeakSanitizer: detected memory leaks
41// CHECK: [[ADDR]] (1337 bytes)
42// CHECK: SUMMARY: {{(Leak|Address)}}Sanitizer:
43// CHECK-sanity: Value after LSan: [[ADDR]].
44