SIGSEGV on startup rtValue::setObject() while compiling using clang 6.0.0

[dwrobel]

Compiling using clang 6.0.0 (./dw.sh ./0150-glut-node8-clang-asan.sh) causes Spark to crash on startup as following:

Thread 1 "pxscene" received signal SIGSEGV, Segmentation fault.
rtValue::setObject (this=0x0, v=0x2b51f20) at /home/sw/projects/pxscene/pxCore/src/rtValue.cpp:238
(gdb) bt
#0  rtValue::setObject (this=0x0, v=0x2b51f20) at /home/sw/projects/pxscene/pxCore/src/rtValue.cpp:238
#1  0x00000000004f7c82 in rtValue::setObject (this=0x0, v=...) at /home/sw/projects/pxscene/pxCore/src/rtValue.cpp:255
#2  0x00000000004f9413 in rtValue::asn (this=<optimized out>, v=warning: can't find linker symbol for virtual table for `rtObjectRef' value
warning:   found `pxConstants::~pxConstants()' instead
...) at /home/sw/projects/pxscene/pxCore/src/rtValue.h:243
#3  rtValue::assign<rtObjectRef> (this=<optimized out>, t=...) at /home/sw/projects/pxscene/pxCore/src/rtValue.h:208
#4  rtPromise::then_thunk (this=<optimized out>, numArgs=<optimized out>, args=<optimized out>, r=...) at /home/sw/projects/pxscene/pxCore/src/rtPromise.h:50
#5  0x00000000004fc8a4 in rtObjectBase::Send (this=<optimized out>, messageName=0x59e96b "then", numArgs=3, args=0x7ffc650a0c30) at /home/sw/projects/pxscene/pxCore/src/rtObject.cpp:493
#6  0x00000000004fcc4e in rtObjectBase::send (this=0x7ffc650a0d00, messageName=0x59e96b "then", arg1=..., arg2=..., arg3=...) at /home/sw/projects/pxscene/pxCore/src/rtObject.cpp:526
#7  0x00000000004e2355 in rtScriptNodeUtils::rtObjectWrapper::createFromObjectReference (ctx=..., ref=...) at /home/sw/projects/pxscene/pxCore/src/rtScriptNode/rtObjectWrapper.cpp:159
#8  0x00000000004e537f in rtScriptNodeUtils::rt2js (ctx=..., v=...) at /home/sw/projects/pxscene/pxCore/src/rtScriptNode/rtWrapperUtils.cpp:428
#9  0x00000000004e39fa in rtScriptNodeUtils::rtObjectWrapper::getProperty<char const*> (prop=@0x7ffc650a0f00: 0x2b4f730 "ready", info=...) at /home/sw/projects/pxscene/pxCore/src/rtScriptNode/rtObjectWrapper.cpp:226
#10 0x00000000004e1d57 in rtScriptNodeUtils::rtObjectWrapper::getPropertyByName (prop=..., info=...) at /home/sw/projects/pxscene/pxCore/src/rtScriptNode/rtObjectWrapper.cpp:289
#11 0x00007fd09754c951 in v8::internal::PropertyCallbackArguments::Call (this=0x7ffc650a0fe0, f=0x4e1d00 <rtScriptNodeUtils::rtObjectWrapper::getPropertyByName(v8::Local<v8::String>, v8::PropertyCallbackInfo<v8::Value> const&)>, name=...) at ../deps/v8/src/handles.h:63
#12 0x00007fd09754d612 in v8::internal::(anonymous namespace)::GetPropertyWithInterceptorInternal(v8::internal::LookupIterator*, v8::internal::Handle<v8::internal::InterceptorInfo>, bool*) () at ../deps/v8/src/objects.cc:1752
#13 0x00007fd09754d706 in v8::internal::JSObject::GetPropertyWithInterceptor (it=it@entry=0x7ffc650a10d0, done=done@entry=0x7ffc650a1087) at ../deps/v8/src/handles-inl.h:118
#14 0x00007fd09755a43b in v8::internal::Object::GetProperty (it=it@entry=0x7ffc650a10d0) at ../deps/v8/src/objects.cc:1043
#15 0x00007fd0974bfa22 in v8::internal::LoadIC::Load (this=this@entry=0x7ffc650a11c0, object=object@entry=..., name=name@entry=...) at ../deps/v8/src/ic/ic.cc:459
#16 0x00007fd0974c1094 in v8::internal::__RT_impl_Runtime_LoadIC_Miss (isolate=0x275c220, args=...) at ../deps/v8/src/ic/ic.cc:2300
#17 v8::internal::Runtime_LoadIC_Miss(int, v8::internal::Object**, v8::internal::Isolate*) () at ../deps/v8/src/ic/ic.cc:2283

[kannanmadanagopalt]

no, I haven't came across this

[dwrobel]

Hint, it crashes when compiling with -O2 - turning it off mitigates the issue.

So, it looks like an optimization related problem. See also frame #2 from the backtrace:

#2` 0x00000000004f9413 in rtValue::asn (this=<optimized out>, v=warning: can't find linker symbol for virtual table for `rtObjectRef' value warning: found `pxConstants::~pxConstants()' instead ...) at /home/sw/projects/pxscene/pxCore/src/rtValue.h:243

looks like a completely different, than expected, object/instance seems to be assigned.