cimport, error: dependency loop detected

[jimying]

Zig Version

0.12.0-dev.1808+69195d0cd

Steps to Reproduce and Observed Behavior

I want to call pjsip(open source: https://github.com/pjsip/pjproject) library in zig.

Here my simple sample : https://github.com/jimying/testpj.zig

steps to build sample (tested in linux x86_64):

# 1. install pjsip library
sh install_pjsip.sh

# 2. build, this step is fail, `error: dependency loop detected`.
zig build 

Expected Behavior

build and run ok

[jimying]

I build success by modify the declare sequeue and works fine.

At the beginning, I suspected that it's a problem with translate-c. But i compare the cimport.zig files, it's same!
This is a very special problem, hope this sample can help to debug.

Follow is the modify patch:

     // problem1: test memory pool  (error: dependency loop detected)
+    var pool: [*c]c.pj_pool_t = undefined;
     var cp: c.pj_caching_pool = undefined;
     c.pj_caching_pool_init(&cp, null, 0);

-    const pool = c.pj_pool_create(&cp.factory, "test", 1000, 1000, null);
+    pool = c.pj_pool_create(&cp.factory, "test", 1000, 1000, null);
     _ = c.pj_pool_alloc(pool, 100);
     c.pj_pool_release(pool);

[sphaerophoria]

Hit this while trying to use miniaudio. Found a stripped down repro which might be helpful

test.h

struct A;
typedef void (*function_callback)(struct A*);

struct A {
	function_callback callback;
};

struct B {
	function_callback callback;
};

.
test.zig

const c = @cImport({
    @cInclude("test.h");
});

pub fn main() void {
    const v: c.B = undefined;
    _ = v;
}

Run with zig run -I. test.zig

• If we try to instantiate c.A instead of c.B, then it is not a problem
• If we replace struct A* with void* in the function callback it is not a problem

Observed on zig 0.12.0 and nightly zig-linux-x86_64-0.13.0-dev.75+5c9eb4081