Rollup merge of #83767 - camelid:mangle-v0-fix, r=nikomatsakis

Fix v0 symbol mangling bug

Fixes #83611.

r? ``@jackh726``

src/test/ui/symbol-names/trait-objects.rs

@@ -0,0 +1,48 @@
+// Ensure that trait objects don't include more than one binder. See #83611
+
+// build-fail
+// revisions: v0
+//[v0]compile-flags: -Z symbol-mangling-version=v0
+//[v0]normalize-stderr-test: "Cs.*?_" -> "CRATE_HASH"
+//[v0]normalize-stderr-test: "core\[.*?\]" -> "core[HASH]"
+
+#![feature(rustc_attrs)]
+
+trait Bar {
+    fn method(&self) {}
+}
+
+impl Bar for &dyn FnMut(&u8) {
+    #[rustc_symbol_name]
+    //[v0]~^ ERROR symbol-name
+    //[v0]~| ERROR demangling
+    //[v0]~| ERROR demangling-alt
+    fn method(&self) {}
+}
+
+trait Foo {
+    fn method(&self) {}
+}
+
+impl Foo for &(dyn FnMut(&u8) + for<'b> Send) {
+    #[rustc_symbol_name]
+    //[v0]~^ ERROR symbol-name
+    //[v0]~| ERROR demangling
+    //[v0]~| ERROR demangling-alt
+    fn method(&self) {}
+}
+
+trait Baz {
+    fn method(&self) {}
+}
+
+impl Baz for &(dyn for<'b> Send + FnMut(&u8)) {
+    #[rustc_symbol_name]
+    //[v0]~^ ERROR symbol-name
+    //[v0]~| ERROR demangling
+    //[v0]~| ERROR demangling-alt
+    fn method(&self) {}
+}
+
+fn main() {
+}

src/test/ui/symbol-names/trait-objects.v0.stderr

@@ -0,0 +1,56 @@
+error: symbol-name(_RNvXCRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuEL_NtB2_3Bar6method)
+  --> $DIR/trait-objects.rs:16:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> as trait_objects[17891616a171812d]::Bar>::method)
+  --> $DIR/trait-objects.rs:16:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> as trait_objects::Bar>::method)
+  --> $DIR/trait-objects.rs:16:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: symbol-name(_RNvXs_CRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuNtNtBI_6marker4SendEL_NtB4_3Foo6method)
+  --> $DIR/trait-objects.rs:28:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> + core[HASH]::marker::Send as trait_objects[17891616a171812d]::Foo>::method)
+  --> $DIR/trait-objects.rs:28:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> + core::marker::Send as trait_objects::Foo>::method)
+  --> $DIR/trait-objects.rs:28:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: symbol-name(_RNvXs0_CRATE_HASH13trait_objectsRDG_INtNtNtCRATE_HASH4core3ops8function5FnMutTRL0_hEEp6OutputuNtNtBJ_6marker4SendEL_NtB5_3Baz6method)
+  --> $DIR/trait-objects.rs:40:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling(<&dyn for<'a> core[HASH]::ops::function::FnMut<(&'a u8,), Output = ()> + core[HASH]::marker::Send as trait_objects[17891616a171812d]::Baz>::method)
+  --> $DIR/trait-objects.rs:40:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: demangling-alt(<&dyn for<'a> core::ops::function::FnMut<(&'a u8,), Output = ()> + core::marker::Send as trait_objects::Baz>::method)
+  --> $DIR/trait-objects.rs:40:5
+   |
+LL |     #[rustc_symbol_name]
+   |     ^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 9 previous errors
+