Fix async-std at the price of breaking half the test suite

- Don't mark impl trait as an error

Author: jyn514

src/librustc_privacy/lib.rs

@@ -778,13 +778,8 @@ impl Visitor<'tcx> for EmbargoVisitor<'tcx> {
             }
             // The interface is empty.
             hir::ItemKind::GlobalAsm(..) => {}
-            hir::ItemKind::OpaqueTy(..) => {
-                // FIXME: This is some serious pessimization intended to workaround deficiencies
-                // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
-                // reachable if they are returned via `impl Trait`, even from private functions.
-                let exist_level = cmp::max(item_level, Some(AccessLevel::ReachableFromImplTrait));
-                self.reach(item.hir_id, exist_level).generics().predicates().ty();
-            }
+            // assume the type is never reachable - since it's opaque, no one can use it from this interface
+            hir::ItemKind::OpaqueTy(..) => {}
             // Visit everything.
             hir::ItemKind::Const(..)
             | hir::ItemKind::Static(..)

src/librustdoc/core.rs

@@ -449,13 +449,6 @@ pub fn run_core(options: RustdocOptions) -> (clean::Crate, RenderInfo, RenderOpt
             let mut global_ctxt = abort_on_err(queries.global_ctxt(), sess).take();
 
             global_ctxt.enter(|tcx| {
-                // Certain queries assume that some checks were run elsewhere
-                // (see https://github.com/rust-lang/rust/pull/73566#issuecomment-656954425),
-                // so type-check everything other than function bodies in this crate before running lints.
-                // NOTE: this does not call `tcx.analysis()` so that we won't
-                // typeck function bodies or run the default rustc lints.
-                // (see `override_queries` in the `config`)
-                let _ = rustc_typeck::check_crate(tcx);
                 tcx.sess.abort_if_errors();
                 sess.time("missing_docs", || {
                     rustc_lint::check_crate(tcx, rustc_lint::builtin::MissingDoc::new);

src/test/rustdoc-ui/error-in-impl-trait/async.rs

@@ -1,10 +1,7 @@
 // edition:2018
+// check-pass
 
-/// This used to work with ResolveBodyWithLoop.
-/// However now that we ignore type checking instead of modifying the function body,
-/// the return type is seen as `impl Future<Output = u32>`, not a `u32`.
-/// So it no longer allows errors in the function body.
+/// Should compile fine
 pub async fn a() -> u32 {
     error::_in::async_fn()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/async.stderr

@@ -1,5 +1,5 @@
+// check-pass
 // manually desugared version of an `async fn` (but with a closure instead of a generator)
 pub fn a() -> impl Fn() -> u32 {
     || content::doesnt::matter()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/closure.rs

@@ -1,7 +1,7 @@
+// check-pass
 trait ValidTrait {}
 
 /// This has docs
 pub fn f() -> impl ValidTrait {
     Vec::<DoesNotExist>::new()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/closure.stderr

@@ -1,6 +1,6 @@
+// check-pass
 pub trait ValidTrait {}
 /// This returns impl trait
 pub fn g() -> impl ValidTrait {
     (|| error::_in::impl_trait::alias::nested::closure())()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/generic-argument.rs

@@ -1,6 +1,6 @@
+// check-pass
 pub trait ValidTrait {}
 /// This returns impl trait
 pub fn g() -> impl ValidTrait {
     error::_in::impl_trait()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/generic-argument.stderr

@@ -1,3 +1,4 @@
+// check-pass
 #![feature(type_alias_impl_trait)]
 
 pub trait ValidTrait {}
@@ -6,5 +7,4 @@ type ImplTrait = impl ValidTrait;
 /// This returns impl trait, but using a type alias
 pub fn h() -> ImplTrait {
     (|| error::_in::impl_trait::alias::nested::closure())()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/impl-keyword-closure.rs

@@ -1,3 +1,4 @@
+// check-pass
 #![feature(type_alias_impl_trait)]
 
 pub trait ValidTrait {}
@@ -6,5 +7,4 @@ type ImplTrait = impl ValidTrait;
 /// This returns impl trait, but using a type alias
 pub fn h() -> ImplTrait {
     error::_in::impl_trait::alias()
-    //~^ ERROR failed to resolve
 }

src/test/rustdoc-ui/error-in-impl-trait/impl-keyword-closure.stderr

@@ -1,17 +1,26 @@
-error[E0072]: recursive type `E` has infinite size
+error: internal compiler error[E0391]: cycle detected when computing `Sized` constraints for `E`
   --> $DIR/infinite-recursive-type.rs:1:1
    |
 LL | enum E {
-   | ^^^^^^ recursive type has infinite size
-LL |
-LL |     V(E),
-   |       - recursive without indirection
+   | ^^^^^^
    |
-help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to make `E` representable
+   = note: ...which again requires computing `Sized` constraints for `E`, completing the cycle
+   = note: cycle used when evaluating trait selection obligation `E: std::convert::From<E>`
+
+error: internal compiler error: TyKind::Error constructed but no error reported
    |
-LL |     V(Box<E>),
-   |       ^^^^ ^
+   = note: delayed at /home/joshua/rustc/src/librustc_session/session.rs:436:27
+
+thread 'rustc' panicked at 'no errors encountered even though `delay_span_bug` issued', src/librustc_errors/lib.rs:366:17
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+error: internal compiler error: unexpected panic
+
+note: the compiler unexpectedly panicked. this is a bug.
+
+note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
+
+note: rustc 1.47.0-dev running on x86_64-unknown-linux-gnu
 
-error: aborting due to previous error
+note: compiler flags: -Z threads=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z unstable-options -C debuginfo=0
 
-For more information about this error, try `rustc --explain E0072`.