libunwind/test/forceunwind.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 // REQUIRES: linux
  11
  12 // TODO: Figure out why this fails with Memory Sanitizer.
  13 // XFAIL: msan
  14
  15 // Basic test for _Unwind_ForcedUnwind.
  16 // See libcxxabi/test/forced_unwind* tests too.
  17
  18 #undef NDEBUG
  19 #include <assert.h>
  20 #include <signal.h>
  21 #include <stdint.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <unwind.h>
  28
  29 // Using __attribute__((section("main_func"))) is Linux specific, but then
  30 // this entire test is marked as requiring Linux, so we should be good.
  31 //
  32 // We don't use dladdr() because on musl it's a no-op when statically linked.
  33 extern char __start_main_func;
  34 extern char __stop_main_func;
  35
  36 void foo();
  37 _Unwind_Exception ex;
  38
  39 _Unwind_Reason_Code stop(int version, _Unwind_Action actions,
  40                          _Unwind_Exception_Class exceptionClass,
  41                          _Unwind_Exception *exceptionObject,
  42                          struct _Unwind_Context *context,
  43                          void *stop_parameter) {
  44   assert(version == 1);
  45   assert((actions & _UA_FORCE_UNWIND) != 0);
  46   (void)exceptionClass;
  47   assert(exceptionObject == &ex);
  48   assert(stop_parameter == &foo);
  49
  50   // Unwind until the main is reached, above frames depend on the platform and
  51   // architecture.
  52   uintptr_t ip = _Unwind_GetIP(context);
  53   if (ip >= (uintptr_t)&__start_main_func &&
  54       ip < (uintptr_t)&__stop_main_func) {
  55     _Exit(0);
  56   }
  57
  58   return _URC_NO_REASON;
  59 }
  60
  61 __attribute__((noinline)) void foo() {
  62
  63   // Arm EHABI defines struct _Unwind_Control_Block as exception
  64   // object. Ensure struct _Unwind_Exception* work there too,
  65   // because _Unwind_Exception in this case is just an alias.
  66   struct _Unwind_Exception *e = &ex;
  67 #if defined(_LIBUNWIND_ARM_EHABI)
  68   // Create a mock exception object.
  69   memset(e, '\0', sizeof(*e));
  70   memcpy(&e->exception_class, "CLNGUNW", sizeof(e->exception_class));
  71 #endif
  72   _Unwind_ForcedUnwind(e, stop, (void *)&foo);
  73 }
  74
  75 __attribute__((section("main_func"))) int main() {
  76   foo();
  77   return -2;
  78 }