Add tests for mixed panic mode restriction and lints

src/test/ui/panic-runtime/auxiliary/needs-abort.rs

@@ -0,0 +1,5 @@
+// compile-flags:-C panic=abort
+// no-prefer-dynamic
+
+#![crate_type = "rlib"]
+#![no_std]

src/test/ui/panic-runtime/auxiliary/needs-unwind.rs

@@ -0,0 +1,13 @@
+// compile-flags:-C panic=unwind
+// no-prefer-dynamic
+
+#![crate_type = "rlib"]
+#![no_std]
+#![feature(c_unwind)]
+
+extern "C-unwind" fn foo() {}
+
+fn bar() {
+    let ptr: extern "C-unwind" fn() = foo;
+    ptr();
+}

src/test/ui/panic-runtime/need-abort-got-unwind.rs

@@ -0,0 +1,9 @@
+// build-fail
+// needs-unwind
+// error-pattern:is incompatible with this crate's strategy of `unwind`
+// aux-build:needs-abort.rs
+// ignore-wasm32-bare compiled with panic=abort by default
+
+extern crate needs_abort;
+
+fn main() {}

src/test/ui/panic-runtime/need-abort-got-unwind.stderr

@@ -0,0 +1,4 @@
+error: the crate `needs_abort` requires panic strategy `abort` which is incompatible with this crate's strategy of `unwind`
+
+error: aborting due to previous error
+

src/test/ui/panic-runtime/need-unwind-got-abort.rs

@@ -0,0 +1,8 @@
+// build-fail
+// error-pattern:is incompatible with this crate's strategy of `abort`
+// aux-build:needs-unwind.rs
+// compile-flags:-C panic=abort
+
+extern crate needs_unwind;
+
+fn main() {}

src/test/ui/panic-runtime/need-unwind-got-abort.stderr

@@ -0,0 +1,6 @@
+error: the linked panic runtime `panic_unwind` is not compiled with this crate's panic strategy `abort`
+
+error: the crate `needs_unwind` requires panic strategy `unwind` which is incompatible with this crate's strategy of `abort`
+
+error: aborting due to 2 previous errors
+

src/test/ui/unwind-abis/ffi-unwind-calls-lint.rs

@@ -0,0 +1,25 @@
+// build-pass
+
+#![feature(c_unwind)]
+#![warn(ffi_unwind_calls)]
+
+mod foo {
+    #[no_mangle]
+    pub extern "C-unwind" fn foo() {}
+}
+
+extern "C-unwind" {
+    fn foo();
+}
+
+fn main() {
+    // Call to Rust function is fine.
+    foo::foo();
+    // Call to foreign function should warn.
+    unsafe { foo(); }
+    //~^ WARNING call to foreign function with FFI-unwind ABI
+    let ptr: extern "C-unwind" fn() = foo::foo;
+    // Call to function pointer should also warn.
+    ptr();
+    //~^ WARNING call to function pointer with FFI-unwind ABI
+}

src/test/ui/unwind-abis/ffi-unwind-calls-lint.stderr

@@ -0,0 +1,20 @@
+warning: call to foreign function with FFI-unwind ABI
+  --> $DIR/ffi-unwind-calls-lint.rs:19:14
+   |
+LL |     unsafe { foo(); }
+   |              ^^^^^ call to foreign function with FFI-unwind ABI
+   |
+note: the lint level is defined here
+  --> $DIR/ffi-unwind-calls-lint.rs:4:9
+   |
+LL | #![warn(ffi_unwind_calls)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: call to function pointer with FFI-unwind ABI
+  --> $DIR/ffi-unwind-calls-lint.rs:23:5
+   |
+LL |     ptr();
+   |     ^^^^^ call to function pointer with FFI-unwind ABI
+
+warning: 2 warnings emitted
+