mirror of https://github.com/rust-lang/rust
33 lines
963 B
Rust
33 lines
963 B
Rust
//@ run-pass
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//@ ignore-windows
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//@ ignore-macos
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//@ ignore-emscripten doesn't support this linkage
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//@ ignore-sgx weak linkage not permitted
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//@ aux-build:linkage1.rs
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#![feature(linkage)]
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extern crate linkage1 as other;
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extern "C" {
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#[linkage = "extern_weak"]
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static foo: *const isize;
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#[linkage = "extern_weak"]
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static something_that_should_never_exist: *mut isize;
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}
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fn main() {
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// It appears that the --as-needed flag to linkers will not pull in a dynamic
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// library unless it satisfies a non weak undefined symbol. The 'other' crate
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// is compiled as a dynamic library where it would only be used for a
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// weak-symbol as part of an executable, so the dynamic library would be
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// discarded. By adding and calling `other::bar`, we get around this problem.
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other::bar();
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unsafe {
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assert!(!foo.is_null());
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assert_eq!(*foo, 3);
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assert!(something_that_should_never_exist.is_null());
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}
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}
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