Cannot reference functions of modules if the dependencies are loaded conditionally

[Logickin-Lambda]

Background

When I was working on a backend of a gui library, upgrading some c based backend into the relative zig implementation (e.g.: c based raylib libarary -> raylib-zig), to ensure backward compatibility, I have conditionally included the c and zig based backend into the build file, branched by an option; however, this cause a problem of any dependencies that is skipped by the condition will never be referenced, losing the ability to auto complete for those modules, but using the correct option to compile the program, those modules works without any issue.

Zig version:

0.15.1

Extension version:

0.6.15

How to Reproduce the Issue

It can be reproduced with the simplest form of the project as long as you have imported a few dependencies along with an conditional branch (usually, the build options), but before showing the issue, I am going to show the control test first by loading two dependencies of choice into the project:

const raylib_dep = b.dependency("raylib_zig", .{
	.target = target,
	.optimize = optimize,
});

const raylib = raylib_dep.module("raylib"); // main raylib module
const raygui = raylib_dep.module("raygui"); // raygui module
const raylib_artifact = raylib_dep.artifact("raylib"); // raylib C library

exe.linkLibrary(raylib_artifact);
exe.root_module.addImport("raylib", raylib);
exe.root_module.addImport("raygui", raygui);

const zglfw = b.dependency("zglfw", .{});
exe.root_module.addImport("zglfw", zglfw.module("root"));

b.installArtifact(exe);

The set up above is the normal usual set up, and by restarting the ZLS server, all of the dependencies are referenced as usual:

However, when I apply an option and branch the dependency based on the newly added option arbitrary_option, as shown:

const arbitrary_option = b.option(bool, "toggle", "just a random toggle that load dependencies conditionally") orelse false;

if (arbitary_option) {
	const raylib_dep = b.dependency("raylib_zig", .{
		.target = target,
		.optimize = optimize,
	});

	const raylib = raylib_dep.module("raylib"); // main raylib module
	const raygui = raylib_dep.module("raygui"); // raygui module
	const raylib_artifact = raylib_dep.artifact("raylib"); // raylib C library

	exe.linkLibrary(raylib_artifact);
	exe.root_module.addImport("raylib", raylib);
	exe.root_module.addImport("raygui", raygui);
} else {
	const zglfw = b.dependency("zglfw", .{});
	exe.root_module.addImport("zglfw", zglfw.module("root"));
}

Only the branch that fulfill the condition can be referenced which is the default value for arbitrary_option (false):

Because of this issue, I can't use the auto complete to fetch the function names and the constants in the dependencies that is not a part in the default build, but compiling them with the correct option is not a problem. Is this an intended design? And what I should do instead if the design is intended? Please also let me know if this problem is related ZLS so that I could refer this problem if needed.

[Vexu]

Are you using nightly? If so then this is caused by zigtools/zls#2504

[Logickin-Lambda]

Unfortunately, I don't think so since I only use the version whatever comes from the vscode extension version 0.6.15.

[Vexu]

I meant your Zig version.

[Logickin-Lambda]

Nope, I am currently use 0.15.1.

Edit: Ah, right. I forgot to include the information about the setup of my project during submission. I am going to include that now.

[llogick]

https://zigtools.org/zls/configure/per-build/

[Vexu]

Sorry, I completely misunderstood the issue. The link posted by llogick is probably what you're looking for.

[Logickin-Lambda]

@Vexu

No worries, and I have found my way out, but @llogick, sorry mate, I have to say: perhaps only sending link as an answer isn't really an ideal response here. Not because you response it wrong, but the documentation is a bit confusing. For example, when I read this:

When value is present, the option will be passed the same as in zig build -Dname=value. When value is null, the option will be passed as a flag instead as in zig build -Dflag.

My intuition goes as the following: "Oh, that means it is the value for the json is '-Dname=value', but what is the name?" I just overlooked the answer, and it took me a bit of time to aware of the name and value literally written in the definition and the structure of the json represented as the zig BuildOption type because they are a bit too subtle.

As a result, it took me many trials, and I have tried toggle, -Dtoggle and even the project name for once for the name parameter, true, "true" and -Dtoggle=true for the value, along with reading other pages to know how to form the json instance, and finally I have found a working solution that is not documented in the guide:

{
    "build_options": [
        {
            "name": "toggle",
            "value": "true"
        },
        {
            "name": "Option-B-And-So-On",
            "value": "any value type in string"
        }
    ]
}

I think the document needs an example, and even in the simplest form could make the guide clearer by 10-folds since reading the guide currently is really like playing a detective game where I need to find evidences and findings and interpret the timeline to find the criminal. Don't get me wrong, I appreciate to have a documentation such that I can find a solution based on it, but it clearly needs some improvements.

Edit: Anyway, Thanks for the help!