libcxxabi/test/backtrace_test.pass.cpp

   1 //===---------------------- backtrace_test.cpp ----------------------------===//
   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 #include <assert.h>
  12 #include <stddef.h>
  13 #include <unwind.h>
  14
  15 extern "C" _Unwind_Reason_Code
  16 trace_function(struct _Unwind_Context*, void* ntraced) {
  17   (*reinterpret_cast<size_t*>(ntraced))++;
  18   // We should never have a call stack this deep...
  19   assert(*reinterpret_cast<size_t*>(ntraced) < 20);
  20   return _URC_NO_REASON;
  21 }
  22
  23 __attribute__ ((__noinline__))
  24 void call3_throw(size_t* ntraced) {
  25   try {
  26     _Unwind_Backtrace(trace_function, ntraced);
  27   } catch (...) {
  28     assert(false);
  29   }
  30 }
  31
  32 __attribute__ ((__noinline__, __disable_tail_calls__))
  33 void call3_nothrow(size_t* ntraced) {
  34   _Unwind_Backtrace(trace_function, ntraced);
  35 }
  36
  37 __attribute__ ((__noinline__, __disable_tail_calls__))
  38 void call2(size_t* ntraced, bool do_throw) {
  39   if (do_throw) {
  40     call3_throw(ntraced);
  41   } else {
  42     call3_nothrow(ntraced);
  43   }
  44 }
  45
  46 __attribute__ ((__noinline__, __disable_tail_calls__))
  47 void call1(size_t* ntraced, bool do_throw) {
  48   call2(ntraced, do_throw);
  49 }
  50
  51 int main() {
  52   size_t throw_ntraced = 0;
  53   size_t nothrow_ntraced = 0;
  54
  55   call1(&nothrow_ntraced, false);
  56
  57   try {
  58     call1(&throw_ntraced, true);
  59   } catch (...) {
  60     assert(false);
  61   }
  62
  63   // Different platforms (and different runtimes) will unwind a different number
  64   // of times, so we can't make any better assumptions than this.
  65   assert(nothrow_ntraced > 1);
  66   assert(throw_ntraced == nothrow_ntraced); // Make sure we unwind through catch
  67   return 0;
  68 }