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-rw-r--r--tests/ui/linkage-attr/linkage1.rs32
1 files changed, 32 insertions, 0 deletions
diff --git a/tests/ui/linkage-attr/linkage1.rs b/tests/ui/linkage-attr/linkage1.rs
new file mode 100644
index 000000000..deab7a251
--- /dev/null
+++ b/tests/ui/linkage-attr/linkage1.rs
@@ -0,0 +1,32 @@
+// 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());
+ }
+}