libcxxabi/test/backtrace_test.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: no-exceptions
  10
  11 // VE only supports SjLj and doesn't provide _Unwind_Backtrace.
  12 // UNSUPPORTED: target={{ve-.*}}
  13
  14 #include <assert.h>
  15 #include <stddef.h>
  16 #include <unwind.h>
  17
  18 extern "C" _Unwind_Reason_Code
  19 trace_function(struct _Unwind_Context*, void* ntraced) {
  20   (*reinterpret_cast<size_t*>(ntraced))++;
  21   // We should never have a call stack this deep...
  22   assert(*reinterpret_cast<size_t*>(ntraced) < 20);
  23   return _URC_NO_REASON;
  24 }
  25
  26 __attribute__ ((__noinline__))
  27 void call3_throw(size_t* ntraced) {
  28   try {
  29     _Unwind_Backtrace(trace_function, ntraced);
  30   } catch (...) {
  31     assert(false);
  32   }
  33 }
  34
  35 __attribute__ ((__noinline__, __disable_tail_calls__))
  36 void call3_nothrow(size_t* ntraced) {
  37   _Unwind_Backtrace(trace_function, ntraced);
  38 }
  39
  40 __attribute__ ((__noinline__, __disable_tail_calls__))
  41 void call2(size_t* ntraced, bool do_throw) {
  42   if (do_throw) {
  43     call3_throw(ntraced);
  44   } else {
  45     call3_nothrow(ntraced);
  46   }
  47 }
  48
  49 __attribute__ ((__noinline__, __disable_tail_calls__))
  50 void call1(size_t* ntraced, bool do_throw) {
  51   call2(ntraced, do_throw);
  52 }
  53
  54 int main(int, char**) {
  55   size_t throw_ntraced = 0;
  56   size_t nothrow_ntraced = 0;
  57
  58   call1(&nothrow_ntraced, false);
  59
  60   try {
  61     call1(&throw_ntraced, true);
  62   } catch (...) {
  63     assert(false);
  64   }
  65
  66   // Different platforms (and different runtimes) will unwind a different number
  67   // of times, so we can't make any better assumptions than this.
  68   assert(nothrow_ntraced > 1);
  69   assert(throw_ntraced == nothrow_ntraced); // Make sure we unwind through catch
  70   return 0;
  71 }