Implement __attribute__((__warn_unused_result__))

[jethrogb]

Input C/C++ Header

__attribute__((__warn_unused_result__)) int f();

Bindgen Invocation

$ bindgen input.h

Actual Results

/* automatically generated by rust-bindgen 0.59.2 */

extern "C" {
    pub fn f() -> ::std::os::raw::c_int;
}

Expected Results

/* automatically generated by rust-bindgen 0.59.2 */

extern "C" {
    #[must_use] pub fn f() -> ::std::os::raw::c_int;
}

[emilio]

Hmm, we're supposed to have some support for this, see tests/expectations/tests/attribute_warn_unused_result.rs

[emilio]

We have this behind the --enable-function-attribute-detection, because it is expensive to detect unfortunately, but we do support this.

[jethrogb]

Would it be ok to filter this through the ParseCallbacks to avoid calling it unnecessarily?