Cannot load runtime value in comptime block

[vast gulch]

Does anyone know what would cause this error message?

/Users/danielbokser/zig/lib/toolbox/memory.zig:286:29: error: cannot load runtime value in comptime block
    const data_opt = toolbox.playdate_realloc(null, n);
~~~~~~~^~~~~~~~~~~~~~~~~

this is the context: https://zigbin.io/27c937

[zinc bay]

To me it looks like you are calling playdate_allocate_memory in a comptime context but I can't tell for sure without the callsite

[vast gulch]

call site is in the zigbin: https://zigbin.io/27c937

[zinc bay]

The call site of playdate_allocate_memory, not playdate_realloc
I don't know why the compiler would think that line is happening at comptime otherwise

[vast gulch]

ah sorry. its on line 17 here: https://zigbin.io/cd666e

[zinc bay]

Hmm, that does seem weird

[vast gulch]

ah sorry: this is where playdate_allocate_memory is used

const platform_allocate_memory = switch (toolbox.THIS_PLATFORM) {
    //.MacOS => unix_allocate_memory,
    //.MacOS => posix_allocate_memory,
    .MacOS => macos_allocate_memory,
    .BoksOS => boksos_allocate_memory,
    .Playdate => playdate_allocate_memory,
};

and THIS_PLATFORM is a comptime value

[tidal thicket]

that's fine, that just means the switch gets evaluated at comptime

but how do we get from platform_allocate_memory to toolbox.os_allocate_object?

[vast gulch]

got it:

pub fn os_allocate_object(comptime T: type) *T {
    var memory = platform_allocate_memory(@sizeOf(T));
    return @ptrCast(*T, @alignCast(@alignOf(T), memory.ptr));
}

so is the issue the T parameter?

[tidal thicket]

no it shouldn't be...

btw platform_allocate_memory should probably take alignment as an argument

unless it's already guaranteed to have maximum alignment

but I have no idea what causes the error tho

unless... could you try .Playdate => &playdate_allocate_memory,?

but that shouldn't actually matter, nvm

[vast gulch]

yea assuming maximum alignment for now since i rarely use the system allocator (but of course that may change in the future)

[vast gulch]

yea same exact compile error

[tidal thicket]

last thing I can think of is if it's something in the definition of toolbox but I doubt it

oooor, it could be that GlobalState is a comptime only type

that's more likely

[vast gulch]

oooh, let me check

[vast gulch]

so how would i check if GlobalState is comptime only? it'd have function pointers that haven't been converted yet?

[tidal thicket]

that's one option, can I see it?

[vast gulch]

that was it! there was function field i forgot to convert

really need better error messages with this comptime function pointer feature lol

[tidal thicket]

in general better errors, but good that you found it 👍