__attribute__((noreturn)) on a returned function pointer makes take itself -> !

Input C/C++ Header

void (__attribute__((noreturn)) *take(int t))(int);

Bindgen Invocation

$ bindgen input.h -- -x c -std=gnu11

Actual Results

bindgen exits 0 and emits:

unsafe extern "C" {
    pub fn take(t: ::std::os::raw::c_int) -> !;
}

The attribute is on the returned function pointer, not on take. take returns a pointer.

libclang's type spelling is void (*(int))(int) __attribute__((noreturn)). FunctionSig::from_ty looks for __attribute__((noreturn)) at paren-depth 0 and sets is_divergent.

Without the attribute, bindgen emits Option<unsafe extern "C" fn(t: c_int)>. void take(int t) __attribute__((noreturn)); correctly becomes -> !.

#2715 / #2716 fixed the argument shape void foo(__attribute__((noreturn)) void (*arg)(void)); (foo(arg: Option<fn() -> !>), no outer -> !). That check skips attributes inside argument parentheses. On a returned pointer clang puts the attribute at the end of the spelling (depth 0), so the same check still fires.

Expected Results

take should return a function pointer (the pointee can be fn(c_int) -> !). It should not be -> !.

Environment

bindgen: 0.73.1 (rust-lang/rust-bindgen 77cbc723)
clang/libclang: Homebrew clang 21.1.8
rustc: 1.97.1
target: aarch64-apple-darwin
OS: macOS

Start at FunctionSig::from_ty and reproduce the issue with the supplied C header and bindgen invocation. Check how attribute((noreturn)) is classified at different parenthesis depths, then verify that take returns a function pointer while only the pointee remains divergent, matching the expected Rust binding.