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//@ run-pass
//@ ignore-windows
//@ ignore-apple
//@ 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());
}
}
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