Engine Version: 4.12.2 final release git commit: d727689444e4fbd689f5e7d924cd0c5b869fccea
The editor process crashes if I add an std::string object. Like this:
// This causes a crash //
{
std::string InnocentString = "INFO would be merged here things;";
check(InnocentString.length() > 0);
}
Here is the Crashes folder with the reports: https://boostslair.com/files/Crashes.7z
The callstack usually includes the string destructor, but it seems that the crash can happen any time after the destructor.
I’ve tried using -ansimalloc and running valgrind on it. Valgrind says there’s an invalid of size 8 just before the memory allocated by the string object.
I tried to get a crash by directly using delete but none of these cause a crash
int* ArrayTest = new int[400];
check(ArrayTest);
memset(ArrayTest, 1, sizeof(int) * 400);
ArrayTest[12] = 12;
check(ArrayTest[12] = 12);
delete[] ArrayTest;
ArrayTest = nullptr;
To reproduce:
-
Create new project from the first person c++ sample
-
Add this to
MyProjectGameMode.hvoid InitGame(const FString & MapName, const FString & Options, FString & ErrorMessage) override;
-
And finally add this to
MyProjectGameMode.cppand hit play. The editor should immediately crash without
showing the messagevoid AMyProjectGameMode::InitGame(const FString & MapName, const FString & Options,
FString & ErrorMessage)
{
Super::InitGame(MapName, Options, ErrorMessage);// This causes a crash // { std::string InnocentString = "INFO would be merged here things;"; check(InnocentString.length() > 0); } GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("This is an on screen message!"));}
Commenting out the string stops the crashing.
Here’s a core file: https://boostslair.com/files/core.15258.7z Here’s the full project I created to test this: https://boostslair.com/files/MyProject_sample_crash.7z
And this is the callstack I get when the editor crashes:
#0 0x00007febe035e702 in free () from /lib64/libc.so.6
#1 0x00007febec8c48a6 in FMallocThreadSafeProxy::Free (this=0x20190a0, Ptr=0xc425f00)
at Runtime/Core/Public/HAL/MallocThreadSafeProxy.h:62
#2 0x00007feb5fe65676 in operator delete (Ptr=0x31)
at /home/hhyyrylainen/Unreal Projects/MyProject/Source/MyProject/MyProject.cpp:6
#3 0x00007feb5fe6907e in __gnu_cxx::new_allocator<char>::deallocate (
__p=0x31 <error: Cannot access memory at address 0x31>, this=<optimized out>)
at /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1/../../../../include/c++/5.3.1/ext/new_allocator.h:110
#4 std::allocator_traits<std::allocator<char> >::deallocate (
__p=0x31 <error: Cannot access memory at address 0x31>, __a=..., __n=<optimized out>)
at /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1/../../../../include/c++/5.3.1/bits/alloc_traits.h:517
#5 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_destroy (
this=<optimized out>, __size=<optimized out>)
at /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1/../../../../include/c++/5.3.1/bits/basic_string.h:185
#6 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose (
this=<optimized out>)
at /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1/../../../../include/c++/5.3.1/bits/basic_string.h:180
#7 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string (
this=<optimized out>)
at /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1/../../../../include/c++/5.3.1/bits/basic_string.h:543
#8 AMyProjectGameMode::InitGame (this=<optimized out>, MapName=..., Options=..., ErrorMessage=...)
at /home/hhyyrylainen/Unreal Projects/MyProject/Source/MyProject/MyProjectGameMode.cpp:37
#9 0x00007febe9d9153a in UWorld::InitializeActorsForPlay (this=<optimized out>, InURL=...,
bResetTime=<optimized out>)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Runtime/Engine/Private/World.cpp:3154
#10 0x00007febe920f560 in UGameInstance::StartPIEGameInstance (this=<optimized out>,
LocalPlayer=<optimized out>, bInSimulateInEditor=<optimized out>,
bAnyBlueprintErrors=<optimized out>, bStartInSpectatorMode=<optimized out>)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Runtime/Engine/Private/GameInstance.cpp:265
#11 0x00007febe2ed3417 in UEditorEngine::CreatePIEGameInstance (this=<optimized out>,
InPIEInstance=<optimized out>, bInSimulateInEditor=<optimized out>,
bAnyBlueprintErrors=<optimized out>,
bStartInSpectatorMode=<error reading variable: access outside bounds of object referenced via synthetic pointer>, bRunAsDedicated=<optimized out>, PIEStartTime=<optimized out>)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Editor/UnrealEd/Private/PlayLevel.cpp:3249
#12 0x00007febe2ecac02 in UEditorEngine::PlayInEditor (this=<optimized out>, InWorld=<optimized out>,
bInSimulateInEditor=<optimized out>)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Editor/UnrealEd/Private/PlayLevel.cpp:2344
#13 0x00007febe2ebb59e in UEditorEngine::StartQueuedPlayMapRequest (this=0x17597c40)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Editor/UnrealEd/Private/PlayLevel.cpp:1097
#14 0x00007febe287a2ad in UEditorEngine::Tick (this=<optimized out>, DeltaSeconds=<optimized out>,
bIdleMode=<optimized out>)
at /home/hhyyrylainen/Projects/UnrealEngine/Engine/Source/Editor/UnrealEd/Private/EditorEngine.cpp:1246
#15 0x00007febe3272170 in UUnrealEdEngine::Tick (this=0x17597c40, DeltaSeconds=0,00833345484,
OS: Fedora 23, Kernel: 4.5.6-200.fc23.x86_64 (x86_64), Desktop: GNOME Shell 3.18.5, Display Driver: NVIDIA 358.16, OpenGL: 4.4.0, Compiler: GCC 5.3.1 20160406 + Clang 3.8.0, File-System: ext4, Screen Resolution: 3840x1080