Memory issue when using cpp operate node , need help

[njikmf]

Tested versions

4.2.2 stable

System information

Win10 , VS2022

Issue description

I want to port a cpp code using godot, so I will not use gdscript or gdextension. From Doc, gdextension can define new node ,then still need gdscript to operate it , add/remove;.

I added simple code to display a cube,

void SceneTree::initialize() {
	ERR_FAIL_NULL(root);
	MainLoop::initialize();
	root->_set_tree(this);

	MeshInstance3D *m_mesh = memnew(MeshInstance3D);
	BoxMesh *m_box_mesh = memnew(BoxMesh);
	root->add_child(m_mesh);
	m_mesh->set_position(Vector3(2, 0, 0));
	m_mesh->set_mesh(m_box_mesh);

}

This is ok, but the strange thing is, If I move these 5 line code to another file, I got memory issue.

A breakpoint instruction (__debugbreak() statement or a similar call) was executed in godot_windows.exe.

 	ntdll.dll!00007ffd3ce2f2d2()	Unknown	Non-user code. Cannot find or open the PDB file.
 	ntdll.dll!00007ffd3ce38092()	Unknown	Non-user code. Cannot find or open the PDB file.
 	ntdll.dll!00007ffd3ce3837a()	Unknown	Non-user code. Cannot find or open the PDB file.
 	ntdll.dll!00007ffd3ce3e001()	Unknown	Non-user code. Cannot find or open the PDB file.
 	ntdll.dll!00007ffd3cdd7442()	Unknown	Non-user code. Cannot find or open the PDB file.
 	ntdll.dll!00007ffd3cd547b1()	Unknown	Non-user code. Cannot find or open the PDB file.
 	igvk64.dll!00007ffccf00855c()	Unknown	Non-user code. Cannot find or open the PDB file.
 	igvk64.dll!00007ffccefee006()	Unknown	Non-user code. Cannot find or open the PDB file.
 	igvk64.dll!00007ffcce3acf94()	Unknown	Non-user code. Cannot find or open the PDB file.
>	godot_windows.exe!RenderingDeviceVulkan::_free_pending_resources(int p_frame) Line 8931	C++	Symbols loaded.
 	godot_windows.exe!RenderingDeviceVulkan::_begin_frame() Line 8722	C++	Symbols loaded.
 	godot_windows.exe!RenderingDeviceVulkan::swap_buffers() Line 8792	C++	Symbols loaded.
 	godot_windows.exe!RenderingServerDefault::_draw(bool p_swap_buffers, double frame_step) Line 99	C++	Symbols loaded.
 	godot_windows.exe!RenderingServerDefault::draw(bool p_swap_buffers, double frame_step) Line 389	C++	Symbols loaded.
 	godot_windows.exe!Main::iteration() Line 3690	C++	Symbols loaded.
 	godot_windows.exe!OS_Windows::run() Line 1474	C++	Symbols loaded.
 	godot_windows.exe!widechar_main(int argc, wchar_t * * argv) Line 182	C++	Symbols loaded.
 	godot_windows.exe!_main() Line 206	C++	Symbols loaded.
 	godot_windows.exe!main(int argc, char * * argv) Line 218	C++	Symbols loaded.
 	[External Code]		Annotated Frame

Then I enabled the Address Sanitizer,

Godot Engine v4.2.2.stable.custom_build.15073afe3 - https://godotengine.org
Vulkan API 1.3.289 - Forward+ - Using Vulkan Device #0: NVIDIA - NVIDIA GeForce GTX 1660

=================================================================
==12716==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x1256f91d9fe0 at pc 0x7ff761a4c767 bp 0x004fdf3af070 sp 0x004fdf3af070
WRITE of size 8 at 0x1256f91d9fe0 thread T0
==12716==WARNING: Failed to use and restart external symbolizer!
    #0 0x7ff761a4c766 in NodePath::NodePath D:\code\cpp\godot-422-gitee\core\string\node_path.h:49
    #1 0x7ff767f89872 in MeshInstance3D::MeshInstance3D D:\code\cpp\godot-422-gitee\scene\3d\mesh_instance_3d.h:47
    #2 0x7ff76a687e2a in ArchlordNode::init D:\code\cpp\godot-422-gitee\archlord\archlord_node.cpp:6
    #3 0x7ff766eff7fa in SceneTree::initialize D:\code\cpp\godot-422-gitee\scene\main\scene_tree.cpp:461
    #4 0x7ff7620903b9 in OS_Windows::run D:\code\cpp\godot-422-gitee\platform\windows\os_windows.cpp:1470
    #5 0x7ff76157e758 in widechar_main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:180
    #6 0x7ff76157e3ed in _main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:204
    #7 0x7ff76157e858 in main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:218
    #8 0x7ff763e740bf in __scrt_common_main_seh D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
    #9 0x7ffed5767343 in BaseThreadInitThunk+0x13 (C:\WINDOWS\System32\KERNEL32.DLL+0x180017343)
    #10 0x7ffed6e026b0 in RtlUserThreadStart+0x20 (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800526b0)

0x1256f91d9fe0 is located 0 bytes after 1632-byte region [0x1256f91d9980,0x1256f91d9fe0)
allocated by thread T0 here:
    #0 0x7ffe9b67f2a8 in _asan_wrap__CrtIsValidHeapPointer+0x2068 (C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.42.34433\bin\HostX64\x64\clang_rt.asan_dynamic-x86_64.dll+0x18004f2a8)
    #1 0x7ff76158f869 in Memory::alloc_static D:\code\cpp\godot-422-gitee\core\os\memory.cpp:75
    #2 0x7ff76158f70a in operator new D:\code\cpp\godot-422-gitee\core\os\memory.cpp:40
    #3 0x7ff76a687e19 in ArchlordNode::init D:\code\cpp\godot-422-gitee\archlord\archlord_node.cpp:6
    #4 0x7ff766eff7fa in SceneTree::initialize D:\code\cpp\godot-422-gitee\scene\main\scene_tree.cpp:461
    #5 0x7ff7620903b9 in OS_Windows::run D:\code\cpp\godot-422-gitee\platform\windows\os_windows.cpp:1470
    #6 0x7ff76157e758 in widechar_main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:180
    #7 0x7ff76157e3ed in _main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:204
    #8 0x7ff76157e858 in main D:\code\cpp\godot-422-gitee\platform\windows\godot_windows.cpp:218
    #9 0x7ff763e740bf in __scrt_common_main_seh D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
    #10 0x7ffed5767343 in BaseThreadInitThunk+0x13 (C:\WINDOWS\System32\KERNEL32.DLL+0x180017343)
    #11 0x7ffed6e026b0 in RtlUserThreadStart+0x20 (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800526b0)

SUMMARY: AddressSanitizer: heap-buffer-overflow D:\code\cpp\godot-422-gitee\core\string\node_path.h:49 in NodePath::NodePath
Shadow bytes around the buggy address:
  0x1256f91d9d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91d9d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91d9e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91d9e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91d9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x1256f91d9f80: 00 00 00 00 00 00 00 00 00 00 00 00[fa]fa fa fa
  0x1256f91da000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x1256f91da080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91da100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91da180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x1256f91da200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb

Can some one told me what's the reason?

Steps to reproduce

add these 5 line code to display a cube,

	MeshInstance3D *m_mesh =memnew(MeshInstance3D);
	BoxMesh *m_box_mesh = memnew(BoxMesh);
	root->add_child(m_mesh);
	m_mesh->set_position(Vector3(2, 0, 0));
	m_mesh->set_mesh(m_box_mesh);

if inside void SceneTree::initialize() , everything is ok, cube will be displayed;
if outside void SceneTree::initialize() , I put it in a custom class , xxxx::init , it crashed

Minimal reproduction project (MRP)

any empty project

[AThousandShips]

This is for reporting bugs, this sounds like a support question, please ask in the other community channels for support questions

[njikmf]

I ask for help because I am not sure is these 5 line code incorrect, or Godot code has memory issue.

[AThousandShips]

Try using the appropriate memory management for your types, it should be Ref<BoxMesh> not BoxMesh *, but if that doesn't help please ask in other channels to confirm that you are using things correctly, and if you are please return here

[njikmf]

I tested, Ref not the problem, Ref class has a constructor to accept raw pointer. I really don't understand why just 5 simple line code cause crash..
These 5 line code is converted from GDscript:

func _ready():
	var mi=MeshInstance3D.new()
	var bm=BoxMesh.new()
	mi.set_position(Vector3(1,0,0))
	mi.set_mesh(bm)
	add_child(mi)

this works well in GDScript, so anyone can explain me why it not work in cpp?

[AThousandShips]

Did you try:

	MeshInstance3D *m_mesh =memnew(MeshInstance3D);
	Ref<BoxMesh> m_box_mesh = memnew(BoxMesh);
	root->add_child(m_mesh);
	m_mesh->set_position(Vector3(2, 0, 0));
	m_mesh->set_mesh(m_box_mesh);

But please ask in the other community channels to make sure this is a bug and not user error, and if it is a bug please provide an example project for testing

[huwpascoe]

Just posting a link to this thread in the discord isn't exactly in the spirit of asking for help...

Without seeing the full source I can only guess, and my guess is that your class ArchlordNode has been put there without any understanding of the engine architecture - SceneTree::initialize is not where your own init should be injected.

Follow this guide for adding internal custom c++
https://docs.godotengine.org/en/stable/contributing/development/core_and_modules/custom_modules_in_cpp.html