Implement stacktrace from current exception for MSVC (#159)

std::current_exception() makes a copy of current exception object
into returned std::exception_ptr. So the tracking of the original
exception object and its stacktrace are lost.

build/Jamfile.v2

@@ -140,13 +140,12 @@ lib boost_stacktrace_from_exception
   : # requirements
     <warnings>all
     <target-os>linux:<library>dl
-    <target-os>windows:<build>no  # not supported at the moment
 
     # Command line option to disable build
     <boost.stacktrace.from_exception>off:<build>no
 
     # Require usable libbacktrace on other platforms
-    [ check-target-builds ../build//libbacktrace : : <build>no ]
+    #[ check-target-builds ../build//libbacktrace : : <build>no ]
   : # default build
   : # usage-requirements
     #<link>shared:<define>BOOST_STACKTRACE_DYN_LINK=1

doc/stacktrace.qbk

@@ -137,7 +137,7 @@ See [link stacktrace.theoretical_async_signal_safety "Theoretical async signal s
 [section Stacktrace from arbitrary exception]
 
 [warning At the moment the functionality is only available for some of the
-         popular C++ runtimes for POSIX systems and requires *libbacktrace*.
+         popular C++ runtimes for POSIX systems with *libbacktrace* and for Windows.
          Make sure that your platform is supported by running some tests.
 ]
 

include/boost/stacktrace/stacktrace.hpp

@@ -33,6 +33,26 @@
 #   pragma warning(disable:2196) // warning #2196: routine is both "inline" and "noinline"
 #endif
 
+#if defined(BOOST_MSVC)
+
+extern "C" {
+
+BOOST_SYMBOL_EXPORT inline void* boost_stacktrace_impl_return_nullptr() { return nullptr; }
+const char* boost_stacktrace_impl_current_exception_stacktrace();
+bool* boost_stacktrace_impl_ref_capture_stacktraces_at_throw();
+
+}
+
+#ifdef _M_IX86
+#   pragma comment(linker, "/ALTERNATENAME:_boost_stacktrace_impl_current_exception_stacktrace=_boost_stacktrace_impl_return_nullptr")
+#   pragma comment(linker, "/ALTERNATENAME:_boost_stacktrace_impl_ref_capture_stacktraces_at_throw=_boost_stacktrace_impl_return_nullptr")
+#else
+#   pragma comment(linker, "/ALTERNATENAME:boost_stacktrace_impl_current_exception_stacktrace=boost_stacktrace_impl_return_nullptr")
+#   pragma comment(linker, "/ALTERNATENAME:boost_stacktrace_impl_ref_capture_stacktraces_at_throw=boost_stacktrace_impl_return_nullptr")
+#endif
+
+#endif
+
 namespace boost { namespace stacktrace {
 
 namespace impl {
@@ -381,6 +401,8 @@ class basic_stacktrace {
         if (impl::current_exception_stacktrace) {
             trace = impl::current_exception_stacktrace();
         }
+#elif defined(BOOST_MSVC)
+        trace = boost_stacktrace_impl_current_exception_stacktrace();
 #endif
 
         if (trace) {

include/boost/stacktrace/this_thread.hpp

@@ -27,6 +27,10 @@ inline void set_capture_stacktraces_at_throw(bool enable = true) noexcept {
     if (impl::ref_capture_stacktraces_at_throw) {
         impl::ref_capture_stacktraces_at_throw() = enable;
     }
+#elif defined(BOOST_MSVC)
+    if (bool* p = boost_stacktrace_impl_ref_capture_stacktraces_at_throw()) {
+        *p = enable;
+    }
 #endif
     (void)enable;
 }
@@ -45,6 +49,10 @@ inline bool get_capture_stacktraces_at_throw() noexcept {
     if (impl::ref_capture_stacktraces_at_throw) {
         return impl::ref_capture_stacktraces_at_throw();
     }
+#elif defined(BOOST_MSVC)
+    if (bool* p = boost_stacktrace_impl_ref_capture_stacktraces_at_throw()) {
+        return *p;
+    }
 #endif
     return false;
 }

src/from_exception.cpp

@@ -4,6 +4,147 @@
 // accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
+#if defined(_MSC_VER)
+
+#include <boost/stacktrace/safe_dump_to.hpp>
+#include <windows.h>
+
+extern "C" void** __cdecl __current_exception(); // exported from vcruntime.dll
+#define _pCurrentException static_cast<PEXCEPTION_RECORD>(*__current_exception())
+
+namespace {
+
+constexpr std::size_t kStacktraceDumpSize = 4096;
+
+struct thrown_info {
+  ULONG_PTR object;
+  char* dump;
+};
+
+struct exception_data {
+  bool capture_stacktraces_at_throw = true;
+  unsigned count = 0;
+  thrown_info* info = nullptr;
+
+  ~exception_data() noexcept {
+    HANDLE hHeap = GetProcessHeap();
+    for (unsigned i = 0; i < count; ++i) {
+      HeapFree(hHeap, 0, info[i].dump);
+    }
+    HeapFree(hHeap, 0, info);
+  }
+};
+
+thread_local exception_data data;
+
+inline bool PER_IS_MSVC_EH(PEXCEPTION_RECORD p) noexcept {
+  const DWORD EH_EXCEPTION_NUMBER = 0xE06D7363;
+  const ULONG_PTR EH_MAGIC_NUMBER1 = 0x19930520;
+
+  return p->ExceptionCode == EH_EXCEPTION_NUMBER &&
+    (p->NumberParameters == 3 || p->NumberParameters == 4) &&
+    p->ExceptionInformation[0] == EH_MAGIC_NUMBER1;
+}
+
+inline ULONG_PTR PER_PEXCEPTOBJ(PEXCEPTION_RECORD p) noexcept {
+  return p->ExceptionInformation[1];
+}
+
+unsigned current_cxx_exception_index() noexcept {
+  if (PEXCEPTION_RECORD current_cxx_exception = _pCurrentException) {
+    for (unsigned i = data.count; i > 0;) {
+      --i;
+      if (data.info[i].object == PER_PEXCEPTOBJ(current_cxx_exception)) {
+        return i;
+      }
+    }
+  }
+  return data.count;
+}
+
+bool is_processing_rethrow(PEXCEPTION_RECORD p) noexcept {
+  // Processing flow:
+  // 0. throw;
+  // 1. _CxxThrowException(pExceptionObject = nullptr)
+  // 2. VEH & SEH (may throw new c++ exceptions!)
+  // 3. __RethrowException(_pCurrentException)
+  // 4. VEH
+  if (PER_PEXCEPTOBJ(p) == 0) return true;
+  PEXCEPTION_RECORD current_cxx_exception = _pCurrentException;
+  if (current_cxx_exception == nullptr) return false;
+  return PER_PEXCEPTOBJ(p) == PER_PEXCEPTOBJ(current_cxx_exception);
+}
+
+LONG NTAPI veh(PEXCEPTION_POINTERS p) {
+  if (data.capture_stacktraces_at_throw &&
+      PER_IS_MSVC_EH(p->ExceptionRecord) &&
+      !is_processing_rethrow(p->ExceptionRecord)) {
+    HANDLE hHeap = GetProcessHeap();
+    unsigned index = current_cxx_exception_index();
+    unsigned new_count = 1 + (index < data.count ? index + 1 : 0);
+
+    for (unsigned i = new_count; i < data.count; ++i) {
+      HeapFree(hHeap, 0, data.info[i].dump);
+      data.info[i].dump = nullptr;
+    }
+
+    void* new_info;
+    if (data.info) {
+      new_info = HeapReAlloc(hHeap, HEAP_ZERO_MEMORY, data.info, sizeof(thrown_info) * new_count);
+    } else {
+      new_info = HeapAlloc(hHeap, HEAP_ZERO_MEMORY, sizeof(thrown_info) * new_count);
+    }
+    if (new_info) {
+      data.count = new_count;
+      data.info = static_cast<thrown_info*>(new_info);
+      data.info[data.count - 1].object = PER_PEXCEPTOBJ(p->ExceptionRecord);
+      char*& dump_ptr = data.info[data.count - 1].dump;
+      if (dump_ptr == nullptr) {
+        dump_ptr = static_cast<char*>(HeapAlloc(hHeap, 0, kStacktraceDumpSize));
+      }
+      if (dump_ptr != nullptr) {
+        const std::size_t kSkip = 4;
+        boost::stacktrace::safe_dump_to(kSkip, dump_ptr, kStacktraceDumpSize);
+      }
+    } else if (new_count <= data.count) {
+      data.count = new_count - 1;
+      HeapFree(hHeap, 0, data.info[data.count - 1].dump);
+      data.info[data.count - 1].dump = nullptr;
+    }
+  }
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+struct veh_installer {
+  PVOID h;
+  veh_installer() noexcept : h(AddVectoredExceptionHandler(1, veh)) {}
+  ~veh_installer() noexcept { RemoveVectoredExceptionHandler(h); }
+} installer;
+
+}
+
+extern "C" {
+
+BOOST_SYMBOL_EXPORT const char* boost_stacktrace_impl_current_exception_stacktrace() {
+  unsigned index = current_cxx_exception_index();
+  return index < data.count ? data.info[index].dump : nullptr;
+}
+
+BOOST_SYMBOL_EXPORT bool* boost_stacktrace_impl_ref_capture_stacktraces_at_throw() {
+  return &data.capture_stacktraces_at_throw;
+}
+
+}
+
+namespace boost { namespace stacktrace { namespace impl {
+
+BOOST_SYMBOL_EXPORT void assert_no_pending_traces() noexcept {
+}
+
+}}}  // namespace boost::stacktrace::impl
+
+#else
+
 #include "exception_headers.h"
 
 // At the moment the file is used only on POSIX. _Unwind_Backtrace may be
@@ -222,3 +363,4 @@ BOOST_SYMBOL_EXPORT void assert_no_pending_traces() noexcept {
 
 }}}  // namespace boost::stacktrace::impl
 
+#endif

test/Jamfile.v2

@@ -183,17 +183,29 @@ test-suite stacktrace_tests
     [ run test_from_exception_none.cpp : : : $(FORCE_SYMBOL_EXPORT) $(BASIC_DEPS) <debug-symbols>on                 : from_exception_none_basic_ho ]
     [ run test_from_exception_none.cpp : : : $(LINKSHARED_BT) <debug-symbols>on                                     : from_exception_none_bt ]
     [ run test_from_exception_none.cpp : : : <define>BOOST_STACKTRACE_USE_BACKTRACE $(BT_DEPS) <debug-symbols>on    : from_exception_none_bt_ho ]
+    [ run test_from_exception_none.cpp : : : $(LINKSHARED_WIND) <debug-symbols>on                                      : from_exception_none_windbg ]
+    [ run test_from_exception_none.cpp : : : <define>BOOST_STACKTRACE_USE_WINDBG $(WIND_DEPS) <debug-symbols>on        : from_exception_none_windbg_ho ]
+    [ run test_from_exception_none.cpp : : : $(LINKSHARED_WIND_CACHED) <debug-symbols>on                               : from_exception_none_windbg_cached ]
+    [ run test_from_exception_none.cpp : : : <define>BOOST_STACKTRACE_USE_WINDBG_CACHED $(WICA_DEPS) <debug-symbols>on : from_exception_none_windbg_cached_ho ]
 
     [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_BASIC) <debug-symbols>on                       : from_exception_disabled_basic ]
     [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(FORCE_SYMBOL_EXPORT) $(BASIC_DEPS) <debug-symbols>on      : from_exception_disabled_basic_ho ]
     [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_BT) <debug-symbols>on                          : from_exception_disabled_bt ]
     [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_BACKTRACE $(BT_DEPS)           : from_exception_disabled_bt_ho ]
+    [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_WIND) <debug-symbols>on                                      : from_exception_disabled_windbg ]
+    [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_WINDBG $(WIND_DEPS) <debug-symbols>on        : from_exception_disabled_windbg_ho ]
+    [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_WIND_CACHED) <debug-symbols>on                               : from_exception_disabled_windbg_cached ]
+    [ run test_from_exception_none.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_WINDBG_CACHED $(WICA_DEPS) <debug-symbols>on : from_exception_disabled_windbg_cached_ho ]
 
     [ link test_from_exception.cpp : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_BASIC) <debug-symbols>on                                  : from_exception_basic ]
     [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_BT) <debug-symbols>on                                  : from_exception_bt ]
+    [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_WIND) <debug-symbols>on                                : from_exception_windbg ]
+    [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception $(LINKSHARED_WIND_CACHED) <debug-symbols>on                         : from_exception_windbg_cached ]
 
     [ link test_from_exception.cpp : <library>/boost/stacktrace//boost_stacktrace_from_exception $(FORCE_SYMBOL_EXPORT) $(BASIC_DEPS) <debug-symbols>on                 : from_exception_basic_ho ]
     [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_BACKTRACE $(BT_DEPS) <debug-symbols>on : from_exception_bt_ho ]
+    [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_WINDBG $(WIND_DEPS) <debug-symbols>on        : from_exception_windbg_ho ]
+    [ run test_from_exception.cpp : : : <library>/boost/stacktrace//boost_stacktrace_from_exception <define>BOOST_STACKTRACE_USE_WINDBG_CACHED $(WICA_DEPS) <debug-symbols>on : from_exception_windbg_cached_ho ]
   ;
 
 # Assuring that examples compile and run. Adding sources from `examples` directory to the `type_index` test suite.

test/test_from_exception.cpp

@@ -31,7 +31,27 @@ BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void in_test_throw_1(const char* msg) {
 
 BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void in_test_throw_2(const char* msg) {
   std::string new_msg{msg};
-  throw std::runtime_error(new_msg);
+  throw std::logic_error(new_msg);
+}
+
+BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void in_test_rethrow_1(const char* msg) {
+  try {
+    in_test_throw_1(msg);
+  } catch (const std::exception&) {
+    throw;
+  }
+}
+
+BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void in_test_rethrow_2(const char* msg) {
+  try {
+    in_test_throw_2(msg);
+  } catch (const std::exception&) {
+    try {
+      in_test_throw_1(msg);
+    } catch (const std::exception&) {}
+
+    throw;
+  }
 }
 
 BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_no_exception() {
@@ -67,6 +87,31 @@ BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_after_other_exception() {
   }
 }
 
+BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_rethrow() {
+  try {
+    in_test_rethrow_1("test rethrow");
+  } catch (const std::exception&) {
+    auto trace = stacktrace::from_current_exception();
+    BOOST_TEST(trace);
+    std::cout << "Tarce in test_rethrow(): " << trace << '\n';
+    BOOST_TEST(to_string(trace).find("in_test_throw_1")   != std::string::npos);
+    BOOST_TEST(to_string(trace).find("in_test_rethrow_1") != std::string::npos);
+  }
+}
+
+BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_rethrow_after_other_exception() {
+  try {
+    in_test_rethrow_2("test_rethrow_after_other_exception");
+  } catch (const std::exception&) {
+    auto trace = stacktrace::from_current_exception();
+    BOOST_TEST(trace);
+    std::cout << "Tarce in test_rethrow_after_other_exception(): " << trace << '\n';
+    BOOST_TEST(to_string(trace).find("in_test_throw_1")   == std::string::npos);
+    BOOST_TEST(to_string(trace).find("in_test_throw_2")   != std::string::npos);
+    BOOST_TEST(to_string(trace).find("in_test_rethrow_2") != std::string::npos);
+  }
+}
+
 BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_nested() {
   try {
     in_test_throw_1("test_other_exception_active");
@@ -103,7 +148,11 @@ BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_rethrow_nested() {
     BOOST_TEST(trace);
     std::cout << "Tarce in test_rethrow_nested(): " << trace << '\n';
     BOOST_TEST(to_string(trace).find("in_test_throw_1") == std::string::npos);
+#if defined(BOOST_MSVC)
+    BOOST_TEST(to_string(trace).find("in_test_throw_2") == std::string::npos);
+#else
     BOOST_TEST(to_string(trace).find("in_test_throw_2") != std::string::npos);
+#endif
   }
 }
 
@@ -133,7 +182,11 @@ BOOST_NOINLINE BOOST_SYMBOL_VISIBLE void test_from_other_thread() {
     BOOST_TEST(trace);
     std::cout << "Tarce in test_rethrow_nested(): " << trace << '\n';
     BOOST_TEST(to_string(trace).find("in_test_throw_1") == std::string::npos);
+#if defined(BOOST_MSVC)
+    BOOST_TEST(to_string(trace).find("in_test_throw_2") == std::string::npos);
+#else
     BOOST_TEST(to_string(trace).find("in_test_throw_2") != std::string::npos);
+#endif
   }
 #endif
 }
@@ -146,6 +199,8 @@ int main() {
   test_no_exception();
   test_trace_from_exception();
   test_after_other_exception();
+  test_rethrow();
+  test_rethrow_after_other_exception();
   test_nested();
   test_rethrow_nested();
   test_from_other_thread();