Auto merge of #34904 - petrochenkov:rustcall, r=nikomatsakis

Properly feature gate all unstable ABIs

Fixes https://github.com/rust-lang/rust/issues/34900
[breaking-change]
r? @pnkfelix

---
Function-visiting machinery for AST/HIR is surprisingly error-prone, it's *very* easy to miss some cases or visit something twice while writing a visitor. This is the true problem behind https://github.com/rust-lang/rust/issues/34900. I'll try to restructure these visitors a bit and send one more PR later.

4 files changed, 61 insertions, 41 deletions

diff --git a/src/test/compile-fail/E0045.rs b/src/test/compile-fail/E0045.rs
index edec911d3c0..2a731596b4b 100644
--- a/src/test/compile-fail/E0045.rs
+++ b/src/test/compile-fail/E0045.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern "rust-call" { fn foo(x: u8, ...); } //~ ERROR E0045
+extern "Rust" { fn foo(x: u8, ...); } //~ ERROR E0045
 
 fn main() {
 }
diff --git a/src/test/compile-fail/feature-gate-abi-vectorcall.rs b/src/test/compile-fail/feature-gate-abi-vectorcall.rs
deleted file mode 100644
index 79f3c8dc776..00000000000
--- a/src/test/compile-fail/feature-gate-abi-vectorcall.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-extern "vectorcall" {   //~ ERROR vectorcall is experimental and subject to change
-    fn bar();
-}
-
-extern "vectorcall" fn baz() {  //~ ERROR vectorcall is experimental and subject to change
-}
-
-fn main() {
-}
diff --git a/src/test/compile-fail/feature-gate-abi.rs b/src/test/compile-fail/feature-gate-abi.rs
new file mode 100644
index 00000000000..0c01f955c06
--- /dev/null
+++ b/src/test/compile-fail/feature-gate-abi.rs
@@ -0,0 +1,60 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Functions
+extern "rust-intrinsic" fn f1() {} //~ ERROR intrinsics are subject to change
+extern "platform-intrinsic" fn f2() {} //~ ERROR platform intrinsics are experimental
+extern "vectorcall" fn f3() {} //~ ERROR vectorcall is experimental and subject to change
+extern "rust-call" fn f4() {} //~ ERROR rust-call ABI is subject to change
+
+// Methods in trait definition
+trait Tr {
+    extern "rust-intrinsic" fn m1(); //~ ERROR intrinsics are subject to change
+    extern "platform-intrinsic" fn m2(); //~ ERROR platform intrinsics are experimental
+    extern "vectorcall" fn m3(); //~ ERROR vectorcall is experimental and subject to change
+    extern "rust-call" fn m4(); //~ ERROR rust-call ABI is subject to change
+
+    extern "rust-intrinsic" fn dm1() {} //~ ERROR intrinsics are subject to change
+    extern "platform-intrinsic" fn dm2() {} //~ ERROR platform intrinsics are experimental
+    extern "vectorcall" fn dm3() {} //~ ERROR vectorcall is experimental and subject to change
+    extern "rust-call" fn dm4() {} //~ ERROR rust-call ABI is subject to change
+}
+
+struct S;
+
+// Methods in trait impl
+impl Tr for S {
+    extern "rust-intrinsic" fn m1() {} //~ ERROR intrinsics are subject to change
+    extern "platform-intrinsic" fn m2() {} //~ ERROR platform intrinsics are experimental
+    extern "vectorcall" fn m3() {} //~ ERROR vectorcall is experimental and subject to change
+    extern "rust-call" fn m4() {} //~ ERROR rust-call ABI is subject to change
+}
+
+// Methods in inherent impl
+impl S {
+    extern "rust-intrinsic" fn im1() {} //~ ERROR intrinsics are subject to change
+    extern "platform-intrinsic" fn im2() {} //~ ERROR platform intrinsics are experimental
+    extern "vectorcall" fn im3() {} //~ ERROR vectorcall is experimental and subject to change
+    extern "rust-call" fn im4() {} //~ ERROR rust-call ABI is subject to change
+}
+
+// Function pointer types
+type A1 = extern "rust-intrinsic" fn(); //~ ERROR intrinsics are subject to change
+type A2 = extern "platform-intrinsic" fn(); //~ ERROR platform intrinsics are experimental
+type A3 = extern "vectorcall" fn(); //~ ERROR vectorcall is experimental and subject to change
+type A4 = extern "rust-call" fn(); //~ ERROR rust-call ABI is subject to change
+
+// Foreign modules
+extern "rust-intrinsic" {} //~ ERROR intrinsics are subject to change
+extern "platform-intrinsic" {} //~ ERROR platform intrinsics are experimental
+extern "vectorcall" {} //~ ERROR vectorcall is experimental and subject to change
+extern "rust-call" {} //~ ERROR rust-call ABI is subject to change
+
+fn main() {}
diff --git a/src/test/compile-fail/feature-gate-rust-call.rs b/src/test/compile-fail/feature-gate-rust-call.rs
deleted file mode 100644
index 029a9cad65f..00000000000
--- a/src/test/compile-fail/feature-gate-rust-call.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-extern "rust-call" fn foo() { } //~ ERROR rust-call ABI is subject to change
-
-trait Foo {
-    extern "rust-call" fn foo();
-}
-
-impl Foo for i32 {
-    extern "rust-call" fn foo() { } //~ ERROR rust-call ABI is subject to change
-}
-
-fn main() { }