rust/src/test/ui/proc-macro/crt-static.rs

// Test proc-macro crate can be built without addtional RUSTFLAGS
// on musl target
// override -Ctarget-feature=-crt-static from compiletest
// compile-flags: -Ctarget-feature=
// build-pass
#![crate_type = "proc-macro"]

extern crate proc_macro;

use proc_macro::TokenStream;

#[proc_macro_derive(Foo)]
pub fn derive_foo(input: TokenStream) -> TokenStream {
    input
}