libunwind/test/unwind_leaffunction.pass.cpp

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // Ensure that leaf function can be unwund.
  11 // REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}}
  12
  13 // TODO: Figure out why this fails with Memory Sanitizer.
  14 // XFAIL: msan
  15
  16 #undef NDEBUG
  17 #include <assert.h>
  18 #include <dlfcn.h>
  19 #include <signal.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/types.h>
  24 #include <unistd.h>
  25 #include <unwind.h>
  26
  27 _Unwind_Reason_Code frame_handler(struct _Unwind_Context* ctx, void* arg) {
  28   (void)arg;
  29   Dl_info info = { 0, 0, 0, 0 };
  30
  31   // Unwind until the main is reached, above frames deeped on the platform and
  32   // architecture.
  33   if (dladdr(reinterpret_cast<void *>(_Unwind_GetIP(ctx)), &info) &&
  34       info.dli_sname && !strcmp("main", info.dli_sname)) {
  35     _Exit(0);
  36   }
  37   return _URC_NO_REASON;
  38 }
  39
  40 void signal_handler(int signum) {
  41   (void)signum;
  42   _Unwind_Backtrace(frame_handler, NULL);
  43   _Exit(-1);
  44 }
  45
  46 __attribute__((noinline)) void crashing_leaf_func(void) {
  47   // libunwind searches for the address before the return address which points
  48   // to the trap instruction. NOP guarantees the trap instruction is not the
  49   // first instruction of the function.
  50   // We should keep this here for other unwinders that also decrement pc.
  51   __asm__ __volatile__("nop");
  52   __builtin_trap();
  53 }
  54
  55 int main(int, char**) {
  56   signal(SIGTRAP, signal_handler);
  57   signal(SIGILL, signal_handler);
  58   crashing_leaf_func();
  59   return -2;
  60 }