LoadError with --inline=no

[jhasse]

When using GLFW.jl (Pkg.add("GLFW")) and callbacks, it only works with --inline=yes. Example code:

import GLFW

GLFW.Init()
window = GLFW.CreateWindow(1, 1, "")
GLFW.SetWindowSizeCallback(window, (_, width, height) -> println(""))

Which works fine except when --inline=no is set:

~ julia --inline=no test.jl 
INFO: loaded GLFW 3.0.4 X11 GLX glXGetProcAddress clock_gettime /dev/js shared from /home/jhasse/.julia/v0.4/GLFW/deps/usr64/lib/libglfw
ERROR: LoadError: type Void has no field callbacks
 in SetWindowSizeCallback at /home/jhasse/.julia/v0.4/GLFW/src/util.jl:34
 in SetWindowSizeCallback at /home/jhasse/.julia/v0.4/GLFW/src/util.jl:44
 in include at ./boot.jl:249
 in include_from_node1 at loading.jl:128
 in process_options at ./client.jl:319
 in _start at ./client.jl:403
while loading /home/jhasse/test.jl, in expression starting on line 5

I'm sorry I can't figure out where exactly it goes wrong as I don't quite understand what is happening inside util.jl. Maybe @jayschwa knows more.

[pao]

Which Julia version?

[jhasse]

julia version 0.4.0-dev+3399

[pao]

Might this be related to Void/Nullable/null/Undef/something else that changed recently in the nothingness department, @JeffBezanson?

[jayschwa]

Sorry for the complexity of that macro in util.jl. If I have some time in the next few days, I'll try to reproduce and boil it down to a kernel.

[timholy]

There are many closed issues about --inline=no, but it seems that they have been fixed (#9536). I'm not sure when +3399 is from, but it's possible you may want to upgrade. If not fixed, then you have a new one...

[jhasse]

Just tried master (154076e): Not fixed :(

[jayschwa]

I boiled down the problem and devised a simple test:

using Base.Test

obj = "some object"
ptr_void = pointer_from_objref(obj)
ptr_type = convert(Ptr{typeof(obj)}, ptr_void)

x = unsafe_pointer_to_objref(ptr_void)
@test typeof(x) == typeof(obj)
@test x == obj

x = unsafe_pointer_to_objref(ptr_type)
@test typeof(x) == typeof(obj)
@test x == obj

unsafe_pointer_to_objref normally returns obj regardless if the given pointer is Void or typed. However, for a typed pointer when --inline=no, unsafe_pointer_to_objref returns nothing. This causes a failure in GLFW.jl at https://github.com/JuliaGL/GLFW.jl/blob/master/src/glfw3.jl#L294 since the ccall is defined as returning a typed pointer.

[vtjnash]

this seems likely to be fixed by #9986, when the codepath taken by that function is changed from an intrinsic to a ccall

[jakebolewski]

This works for me now, please respond if this is still an issue.