Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/src/test/ui/linkage-attr/linkage1.rs b/src/test/ui/linkage-attr/linkage1.rs
new file mode 100644
index 000000000..deab7a251
--- /dev/null
+++ b/src/test/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());
+    }
+}