test/badAltHandler.m

   1 /* TEST_CONFIG OS=macosx
   2    TEST_CRASHES
   3
   4 TEST_RUN_OUTPUT
   5 objc\[\d+\]: objc_removeExceptionHandler\(\) called with unknown alt handler; this is probably a bug in multithreaded AppKit use. Set environment variable OBJC_DEBUG_ALT_HANDLERS=YES or break in objc_alt_handler_error\(\) to debug.
   6 objc\[\d+\]: objc_removeExceptionHandler\(\) called with unknown alt handler; this is probably a bug in multithreaded AppKit use.
   7 objc\[\d+\]: HALTED
   8 END
   9 */
  10
  11 #include "test.h"
  12
  13 #include <objc/objc-exception.h>
  14
  15 /*
  16   rdar://6888838
  17   Mail installs an alt handler on one thread and deletes it on another.
  18   This confuses the alt handler machinery, which halts the process.
  19 */
  20
  21 uintptr_t Token;
  22
  23 void handler(id unused __unused, void *context __unused)
  24 {
  25 }
  26
  27 int main()
  28 {
  29 #if __clang__ && __cplusplus
  30     // alt handlers need the objc personality
  31     // catch (id) workaround forces the objc personality
  32     @try {
  33         testwarn("rdar://9183014 clang uses wrong exception personality");
  34     } @catch (id e __unused) {
  35     }
  36 #endif
  37
  38     @try {
  39         // Install 4 alt handlers
  40         uintptr_t t1, t2, t3, t4;
  41         t1 = objc_addExceptionHandler(&handler, NULL);
  42         t2 = objc_addExceptionHandler(&handler, NULL);
  43         t3 = objc_addExceptionHandler(&handler, NULL);
  44         t4 = objc_addExceptionHandler(&handler, NULL);
  45
  46         // Remove 3 of them.
  47         objc_removeExceptionHandler(t1);
  48         objc_removeExceptionHandler(t2);
  49         objc_removeExceptionHandler(t3);
  50
  51         // Create an alt handler on another thread
  52         // that collides with one of the removed handlers
  53         testonthread(^{
  54             @try {
  55                 Token = objc_addExceptionHandler(&handler, NULL);
  56             } @catch (...) {
  57             }
  58         });
  59
  60         // Incorrectly remove the other thread's handler
  61         objc_removeExceptionHandler(Token);
  62         // Remove the 4th handler
  63         objc_removeExceptionHandler(t4);
  64
  65         // Install 8 more handlers.
  66         // If the other thread's handler was not ignored,
  67         // this will fail.
  68         objc_addExceptionHandler(&handler, NULL);
  69         objc_addExceptionHandler(&handler, NULL);
  70         objc_addExceptionHandler(&handler, NULL);
  71         objc_addExceptionHandler(&handler, NULL);
  72         objc_addExceptionHandler(&handler, NULL);
  73         objc_addExceptionHandler(&handler, NULL);
  74         objc_addExceptionHandler(&handler, NULL);
  75         objc_addExceptionHandler(&handler, NULL);
  76     } @catch (...) {
  77     }
  78
  79     // This should have crashed earlier.
  80     fail(__FILE__);
  81 }