mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-12 00:24:03 +00:00
33 lines
957 B
Rust
33 lines
957 B
Rust
// run-pass
|
|
// ignore-windows
|
|
// ignore-macos
|
|
// ignore-emscripten doesn't support this linkage
|
|
// ignore-sgx weak linkage not permitted
|
|
// aux-build:linkage1.rs
|
|
|
|
#![feature(linkage)]
|
|
|
|
extern crate linkage1 as other;
|
|
|
|
extern "C" {
|
|
#[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());
|
|
}
|
|
}
|