| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // ignore-windows |
| // ignore-macos |
| // ignore-emscripten |
| // aux-build:linkage1.rs |
| |
| #![feature(linkage)] |
| |
| extern crate linkage1 as other; |
| |
| extern { |
| #[linkage = "extern_weak"] |
| static foo: *const isize; |
| #[linkage = "extern_weak"] |
| static something_that_should_never_exist: *mut isize; |
| } |
| |
| fn main() { |
| // It appears that the --as-needed flag to linkers will not pull in a dynamic |
| // library unless it satisfies a non weak undefined symbol. The 'other' crate |
| // is compiled as a dynamic library where it would only be used for a |
| // weak-symbol as part of an executable, so the dynamic library would be |
| // discarded. By adding and calling `other::bar`, we get around this problem. |
| other::bar(); |
| |
| unsafe { |
| assert!(!foo.is_null()); |
| assert_eq!(*foo, 3); |
| assert!(something_that_should_never_exist.is_null()); |
| } |
| } |