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1 // RUN: %clangxx_asan -O0 -mllvm -asan-instrument-dynamic-allocas %s -o %t
2 // RUN: %run %t 2>&1
3 //
4 // REQUIRES: stable-runtime
5 
6 // This testcase checks that allocas and VLAs inside loop are correctly unpoisoned.
7 
8 #include <assert.h>
9 #include <stdint.h>
10 #include <stdlib.h>
11 #include "sanitizer/asan_interface.h"
12 
13 // MSVC provides _alloca instead of alloca.
14 #if defined(_MSC_VER) && !defined(alloca)
15 # define alloca _alloca
16 #endif
17 
18 #if defined(__sun__) && defined(__svr4__)
19 #include <alloca.h>
20 #endif
21 
22 void *top, *bot;
23 
foo(int len)24 __attribute__((noinline)) void foo(int len) {
25   char x;
26   top = &x;
27   char array[len];
28   assert(!(reinterpret_cast<uintptr_t>(array) & 31L));
29   alloca(len);
30   for (int i = 0; i < 32; ++i) {
31     char array[i];
32     bot = alloca(i);
33     assert(!(reinterpret_cast<uintptr_t>(bot) & 31L));
34   }
35 }
36 
main(int argc,char ** argv)37 int main(int argc, char **argv) {
38   foo(32);
39   void *q = __asan_region_is_poisoned(bot, (char *)top - (char *)bot);
40   assert(!q);
41   return 0;
42 }
43