Core/CrashHandler: Attempt to extract C++ exception object in uncaught exception hander

1 files changed, 98 insertions, 21 deletions

diff --git a/src/common/Debugging/WheatyExceptionReport.cpp b/src/common/Debugging/WheatyExceptionReport.cpp
index c4de34bb38c..c95d5fd4d3b 100644
--- a/src/common/Debugging/WheatyExceptionReport.cpp
+++ b/src/common/Debugging/WheatyExceptionReport.cpp
@@ -25,6 +25,8 @@
 #include "Errors.h"
 #include "GitRevision.h"
 #include <algorithm>
+#include <ehdata.h>
+#include <rttidata.h>
 
 #define CrashFolder _T("Crashes")
 #pragma comment(linker, "/DEFAULTLIB:dbghelp.lib")
@@ -582,6 +584,80 @@ PEXCEPTION_POINTERS pExceptionInfo)
                 ErrorMessage(GetLastError()));
         }
 
+        if (pExceptionRecord->ExceptionCode == 0xE06D7363 && pExceptionRecord->NumberParameters >= 2)
+        {
+            PVOID exceptionObject = reinterpret_cast<PVOID>(pExceptionRecord->ExceptionInformation[1]);
+            ThrowInfo const* throwInfo = reinterpret_cast<ThrowInfo const*>(pExceptionRecord->ExceptionInformation[2]);
+            auto resolveExceptionRVA = [pExceptionRecord](int32 rva) -> DWORD_PTR
+            {
+                return rva + (pExceptionRecord->NumberParameters >= 4 ? pExceptionRecord->ExceptionInformation[3] : 0);
+            };
+
+            CatchableTypeArray const* catchables = reinterpret_cast<CatchableTypeArray const*>(resolveExceptionRVA(throwInfo->pCatchableTypeArray));
+            CatchableType const* catchable = catchables->nCatchableTypes ? reinterpret_cast<CatchableType const*>(resolveExceptionRVA(catchables->arrayOfCatchableTypes[0])) : nullptr;
+            TypeDescriptor const* exceptionTypeinfo = catchable ? reinterpret_cast<TypeDescriptor const*>(resolveExceptionRVA(catchable->pType)) : nullptr;
+
+            if (exceptionTypeinfo)
+            {
+                void* stdExceptionTypeInfo = []() -> void*
+                {
+                    try
+                    {
+                        std::exception fake;
+                        return __RTtypeid(&fake);
+                    }
+                    catch (...)
+                    {
+                        return nullptr;
+                    }
+                }();
+                std::exception const* exceptionPtr = [](void* object, TypeDescriptor const* typeInfo, void* stdExceptionTypeInfo) -> std::exception const*
+                {
+                    try
+                    {
+                        // real_type descriptor is obtained by parsing throwinfo
+                        // equivalent to expression like this
+                        // std::exception* e = object;
+                        // real_type* r = dynamic_cast<real_type*>(e);
+                        // return r;
+                        return reinterpret_cast<std::exception const*>(__RTDynamicCast(object, 0, stdExceptionTypeInfo, (void*)typeInfo, false));
+                    }
+                    catch (...)
+                    {
+                        return nullptr;
+                    }
+                }(exceptionObject, exceptionTypeinfo, stdExceptionTypeInfo);
+
+                // dynamic_cast<type>(variable_that_already_has_that_type) is optimized away by compiler and attempting to call __RTDynamicCast fails for it
+                if (!exceptionPtr && exceptionTypeinfo == stdExceptionTypeInfo)
+                    exceptionPtr = reinterpret_cast<std::exception*>(exceptionObject);
+
+                Log(_T("\r\nUncaught C++ exception info:"));
+                if (exceptionPtr)
+                    Log(_T(" %s"), exceptionPtr->what());
+
+                Log(_T("\r\n"));
+
+                char undName[MAX_SYM_NAME] = { };
+                if (UnDecorateSymbolName(&exceptionTypeinfo->name[1], &undName[0], MAX_SYM_NAME, UNDNAME_32_BIT_DECODE | UNDNAME_NAME_ONLY | UNDNAME_NO_ARGUMENTS))
+                {
+                    char buf[MAX_SYM_NAME + sizeof(SYMBOL_INFO)] = { };
+                    PSYMBOL_INFO sym = (PSYMBOL_INFO)&buf[0];
+                    sym->SizeOfStruct = sizeof(SYMBOL_INFO);
+                    sym->MaxNameLen = MAX_SYM_NAME;
+                    if (SymGetTypeFromName(m_hProcess, (ULONG64)GetModuleHandle(nullptr), undName, sym))
+                    {
+                        sym->Address = pExceptionRecord->ExceptionInformation[1];
+                        sym->Flags = 0;
+                        char const* variableName = "uncaught_exception";
+                        memset(sym->Name, 0, MAX_SYM_NAME);
+                        memcpy(sym->Name, variableName, strlen(variableName));
+                        FormatSymbolValue(sym, nullptr);
+                    }
+                }
+            }
+        }
+
         CONTEXT trashableContext = *pCtx;
 
         WriteStackDetails(&trashableContext, false, NULL);
@@ -617,27 +693,28 @@ LPCTSTR WheatyExceptionReport::GetExceptionString(DWORD dwCode)
     switch (dwCode)
     {
         EXCEPTION(ACCESS_VIOLATION)
-            EXCEPTION(DATATYPE_MISALIGNMENT)
-            EXCEPTION(BREAKPOINT)
-            EXCEPTION(SINGLE_STEP)
-            EXCEPTION(ARRAY_BOUNDS_EXCEEDED)
-            EXCEPTION(FLT_DENORMAL_OPERAND)
-            EXCEPTION(FLT_DIVIDE_BY_ZERO)
-            EXCEPTION(FLT_INEXACT_RESULT)
-            EXCEPTION(FLT_INVALID_OPERATION)
-            EXCEPTION(FLT_OVERFLOW)
-            EXCEPTION(FLT_STACK_CHECK)
-            EXCEPTION(FLT_UNDERFLOW)
-            EXCEPTION(INT_DIVIDE_BY_ZERO)
-            EXCEPTION(INT_OVERFLOW)
-            EXCEPTION(PRIV_INSTRUCTION)
-            EXCEPTION(IN_PAGE_ERROR)
-            EXCEPTION(ILLEGAL_INSTRUCTION)
-            EXCEPTION(NONCONTINUABLE_EXCEPTION)
-            EXCEPTION(STACK_OVERFLOW)
-            EXCEPTION(INVALID_DISPOSITION)
-            EXCEPTION(GUARD_PAGE)
-            EXCEPTION(INVALID_HANDLE)
+        EXCEPTION(DATATYPE_MISALIGNMENT)
+        EXCEPTION(BREAKPOINT)
+        EXCEPTION(SINGLE_STEP)
+        EXCEPTION(ARRAY_BOUNDS_EXCEEDED)
+        EXCEPTION(FLT_DENORMAL_OPERAND)
+        EXCEPTION(FLT_DIVIDE_BY_ZERO)
+        EXCEPTION(FLT_INEXACT_RESULT)
+        EXCEPTION(FLT_INVALID_OPERATION)
+        EXCEPTION(FLT_OVERFLOW)
+        EXCEPTION(FLT_STACK_CHECK)
+        EXCEPTION(FLT_UNDERFLOW)
+        EXCEPTION(INT_DIVIDE_BY_ZERO)
+        EXCEPTION(INT_OVERFLOW)
+        EXCEPTION(PRIV_INSTRUCTION)
+        EXCEPTION(IN_PAGE_ERROR)
+        EXCEPTION(ILLEGAL_INSTRUCTION)
+        EXCEPTION(NONCONTINUABLE_EXCEPTION)
+        EXCEPTION(STACK_OVERFLOW)
+        EXCEPTION(INVALID_DISPOSITION)
+        EXCEPTION(GUARD_PAGE)
+        EXCEPTION(INVALID_HANDLE)
+        case 0xE06D7363: return _T("Unhandled C++ exception");
     }
 
     // If not one of the "known" exceptions, try to get the string