[beta] ICE fixes for newly stabilized features

src/librustc/hir/lowering.rs

@@ -780,8 +780,9 @@ impl<'a> LoweringContext<'a> {
                 _ => None,
             }),
             |this| {
+                let itctx = ImplTraitContext::Universal(parent_id);
                 this.collect_in_band_defs(parent_id, anonymous_lifetime_mode, |this| {
-                    (this.lower_generics(generics), f(this))
+                    (this.lower_generics(generics, itctx), f(this))
                 })
             },
         );
@@ -1043,7 +1044,11 @@ impl<'a> LoweringContext<'a> {
                 }),
                 |this| {
                     hir::TyBareFn(P(hir::BareFnTy {
-                        generic_params: this.lower_generic_params(&f.generic_params, &NodeMap()),
+                        generic_params: this.lower_generic_params(
+                            &f.generic_params,
+                            &NodeMap(),
+                            ImplTraitContext::Disallowed,
+                        ),
                         unsafety: this.lower_unsafety(f.unsafety),
                         abi: f.abi,
                         decl: this.lower_fn_decl(&f.decl, None, false),
@@ -1784,7 +1789,12 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
-    fn lower_ty_param(&mut self, tp: &TyParam, add_bounds: &[TyParamBound]) -> hir::TyParam {
+    fn lower_ty_param(
+        &mut self,
+        tp: &TyParam,
+        add_bounds: &[TyParamBound],
+        itctx: ImplTraitContext,
+    ) -> hir::TyParam {
         let mut name = self.lower_ident(tp.ident);
 
         // Don't expose `Self` (recovered "keyword used as ident" parse error).
@@ -1794,7 +1804,6 @@ impl<'a> LoweringContext<'a> {
             name = Symbol::gensym("Self");
         }
 
-        let itctx = ImplTraitContext::Universal(self.resolver.definitions().local_def_id(tp.id));
         let mut bounds = self.lower_bounds(&tp.bounds, itctx);
         if !add_bounds.is_empty() {
             bounds = bounds
@@ -1878,6 +1887,7 @@ impl<'a> LoweringContext<'a> {
         &mut self,
         params: &Vec<GenericParam>,
         add_bounds: &NodeMap<Vec<TyParamBound>>,
+        itctx: ImplTraitContext,
     ) -> hir::HirVec<hir::GenericParam> {
         params
             .iter()
@@ -1888,12 +1898,13 @@ impl<'a> LoweringContext<'a> {
                 GenericParam::Type(ref ty_param) => hir::GenericParam::Type(self.lower_ty_param(
                     ty_param,
                     add_bounds.get(&ty_param.id).map_or(&[][..], |x| &x),
+                    itctx,
                 )),
             })
             .collect()
     }
 
-    fn lower_generics(&mut self, g: &Generics) -> hir::Generics {
+    fn lower_generics(&mut self, g: &Generics, itctx: ImplTraitContext) -> hir::Generics {
         // Collect `?Trait` bounds in where clause and move them to parameter definitions.
         // FIXME: This could probably be done with less rightward drift. Also looks like two control
         //        paths where report_error is called are also the only paths that advance to after
@@ -1946,7 +1957,7 @@ impl<'a> LoweringContext<'a> {
         }
 
         hir::Generics {
-            params: self.lower_generic_params(&g.params, &add_bounds),
+            params: self.lower_generic_params(&g.params, &add_bounds, itctx),
             where_clause: self.lower_where_clause(&g.where_clause),
             span: g.span,
         }
@@ -1980,6 +1991,7 @@ impl<'a> LoweringContext<'a> {
                             bound_generic_params: this.lower_generic_params(
                                 bound_generic_params,
                                 &NodeMap(),
+                                ImplTraitContext::Disallowed,
                             ),
                             bounded_ty: this.lower_ty(bounded_ty, ImplTraitContext::Disallowed),
                             bounds: bounds
@@ -2063,7 +2075,8 @@ impl<'a> LoweringContext<'a> {
         p: &PolyTraitRef,
         itctx: ImplTraitContext,
     ) -> hir::PolyTraitRef {
-        let bound_generic_params = self.lower_generic_params(&p.bound_generic_params, &NodeMap());
+        let bound_generic_params =
+            self.lower_generic_params(&p.bound_generic_params, &NodeMap(), itctx);
         let trait_ref = self.with_parent_impl_lifetime_defs(
             &bound_generic_params
                 .iter()
@@ -2218,7 +2231,7 @@ impl<'a> LoweringContext<'a> {
             ItemKind::GlobalAsm(ref ga) => hir::ItemGlobalAsm(self.lower_global_asm(ga)),
             ItemKind::Ty(ref t, ref generics) => hir::ItemTy(
                 self.lower_ty(t, ImplTraitContext::Disallowed),
-                self.lower_generics(generics),
+                self.lower_generics(generics, ImplTraitContext::Disallowed),
             ),
             ItemKind::Enum(ref enum_definition, ref generics) => hir::ItemEnum(
                 hir::EnumDef {
@@ -2228,15 +2241,21 @@ impl<'a> LoweringContext<'a> {
                         .map(|x| self.lower_variant(x))
                         .collect(),
                 },
-                self.lower_generics(generics),
+                self.lower_generics(generics, ImplTraitContext::Disallowed),
             ),
             ItemKind::Struct(ref struct_def, ref generics) => {
                 let struct_def = self.lower_variant_data(struct_def);
-                hir::ItemStruct(struct_def, self.lower_generics(generics))
+                hir::ItemStruct(
+                    struct_def,
+                    self.lower_generics(generics, ImplTraitContext::Disallowed),
+                )
             }
             ItemKind::Union(ref vdata, ref generics) => {
                 let vdata = self.lower_variant_data(vdata);
-                hir::ItemUnion(vdata, self.lower_generics(generics))
+                hir::ItemUnion(
+                    vdata,
+                    self.lower_generics(generics, ImplTraitContext::Disallowed),
+                )
             }
             ItemKind::Impl(
                 unsafety,
@@ -2315,13 +2334,13 @@ impl<'a> LoweringContext<'a> {
                 hir::ItemTrait(
                     self.lower_is_auto(is_auto),
                     self.lower_unsafety(unsafety),
-                    self.lower_generics(generics),
+                    self.lower_generics(generics, ImplTraitContext::Disallowed),
                     bounds,
                     items,
                 )
             }
             ItemKind::TraitAlias(ref generics, ref bounds) => hir::ItemTraitAlias(
-                self.lower_generics(generics),
+                self.lower_generics(generics, ImplTraitContext::Disallowed),
                 self.lower_bounds(bounds, ImplTraitContext::Disallowed),
             ),
             ItemKind::MacroDef(..) | ItemKind::Mac(..) => panic!("Shouldn't still be around"),
@@ -2456,7 +2475,7 @@ impl<'a> LoweringContext<'a> {
 
             let (generics, node) = match i.node {
                 TraitItemKind::Const(ref ty, ref default) => (
-                    this.lower_generics(&i.generics),
+                    this.lower_generics(&i.generics, ImplTraitContext::Disallowed),
                     hir::TraitItemKind::Const(
                         this.lower_ty(ty, ImplTraitContext::Disallowed),
                         default
@@ -2497,7 +2516,7 @@ impl<'a> LoweringContext<'a> {
                     )
                 }
                 TraitItemKind::Type(ref bounds, ref default) => (
-                    this.lower_generics(&i.generics),
+                    this.lower_generics(&i.generics, ImplTraitContext::Disallowed),
                     hir::TraitItemKind::Type(
                         this.lower_bounds(bounds, ImplTraitContext::Disallowed),
                         default
@@ -2554,7 +2573,7 @@ impl<'a> LoweringContext<'a> {
                 ImplItemKind::Const(ref ty, ref expr) => {
                     let body_id = this.lower_body(None, |this| this.lower_expr(expr));
                     (
-                        this.lower_generics(&i.generics),
+                        this.lower_generics(&i.generics, ImplTraitContext::Disallowed),
                         hir::ImplItemKind::Const(
                             this.lower_ty(ty, ImplTraitContext::Disallowed),
                             body_id,
@@ -2585,7 +2604,7 @@ impl<'a> LoweringContext<'a> {
                     )
                 }
                 ImplItemKind::Type(ref ty) => (
-                    this.lower_generics(&i.generics),
+                    this.lower_generics(&i.generics, ImplTraitContext::Disallowed),
                     hir::ImplItemKind::Type(this.lower_ty(ty, ImplTraitContext::Disallowed)),
                 ),
                 ImplItemKind::Macro(..) => panic!("Shouldn't exist any more"),

src/librustc/infer/anon_types/mod.rs

@@ -533,10 +533,14 @@ impl<'cx, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for ReverseMapper<'cx, 'gcx, 'tcx>
         match r {
             // ignore bound regions that appear in the type (e.g., this
             // would ignore `'r` in a type like `for<'r> fn(&'r u32)`.
-            ty::ReLateBound(..) => return r,
+            ty::ReLateBound(..) |
 
             // ignore `'static`, as that can appear anywhere
-            ty::ReStatic => return r,
+            ty::ReStatic |
+
+            // ignore `ReScope`, as that can appear anywhere
+            // See `src/test/run-pass/issue-49556.rs` for example.
+            ty::ReScope(..) => return r,
 
             _ => { }
         }

src/librustc/infer/error_reporting/mod.rs

@@ -181,7 +181,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                 self.msg_span_from_early_bound_and_free_regions(region)
             },
             ty::ReStatic => ("the static lifetime".to_owned(), None),
-            _ => bug!(),
+            _ => bug!("{:?}", region),
         }
     }
 

src/librustc_mir/monomorphize/collector.rs

@@ -212,8 +212,6 @@ use monomorphize::item::{MonoItemExt, DefPathBasedNames, InstantiationMode};
 
 use rustc_data_structures::bitvec::BitVector;
 
-use std::iter;
-
 #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
 pub enum MonoItemCollectionMode {
     Eager,
@@ -1030,13 +1028,15 @@ impl<'b, 'a, 'v> RootCollector<'b, 'a, 'v> {
         // late-bound regions, since late-bound
         // regions must appear in the argument
         // listing.
-        let main_ret_ty = main_ret_ty.no_late_bound_regions().unwrap();
+        let main_ret_ty = self.tcx.erase_regions(
+            &main_ret_ty.no_late_bound_regions().unwrap(),
+        );
 
         let start_instance = Instance::resolve(
             self.tcx,
             ty::ParamEnv::reveal_all(),
             start_def_id,
-            self.tcx.mk_substs(iter::once(Kind::from(main_ret_ty)))
+            self.tcx.intern_substs(&[Kind::from(main_ret_ty)])
         ).unwrap();
 
         self.output.push(create_fn_mono_item(start_instance));

src/librustc_trans/base.rs

@@ -82,7 +82,6 @@ use std::str;
 use std::sync::Arc;
 use std::time::{Instant, Duration};
 use std::{i32, usize};
-use std::iter;
 use std::sync::mpsc;
 use syntax_pos::Span;
 use syntax_pos::symbol::InternedString;
@@ -553,7 +552,9 @@ fn maybe_create_entry_wrapper(cx: &CodegenCx) {
         // late-bound regions, since late-bound
         // regions must appear in the argument
         // listing.
-        let main_ret_ty = main_ret_ty.no_late_bound_regions().unwrap();
+        let main_ret_ty = cx.tcx.erase_regions(
+            &main_ret_ty.no_late_bound_regions().unwrap(),
+        );
 
         if declare::get_defined_value(cx, "main").is_some() {
             // FIXME: We should be smart and show a better diagnostic here.
@@ -580,8 +581,11 @@ fn maybe_create_entry_wrapper(cx: &CodegenCx) {
 
         let (start_fn, args) = if use_start_lang_item {
             let start_def_id = cx.tcx.require_lang_item(StartFnLangItem);
-            let start_fn = callee::resolve_and_get_fn(cx, start_def_id, cx.tcx.mk_substs(
-                iter::once(Kind::from(main_ret_ty))));
+            let start_fn = callee::resolve_and_get_fn(
+                cx,
+                start_def_id,
+                cx.tcx.intern_substs(&[Kind::from(main_ret_ty)]),
+            );
             (start_fn, vec![bx.pointercast(rust_main, Type::i8p(cx).ptr_to()),
                             arg_argc, arg_argv])
         } else {

src/test/compile-fail/issue-47715.rs

@@ -0,0 +1,38 @@
+// Copyright 2018 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.
+
+trait Foo {}
+
+trait Bar<T> {}
+
+trait Iterable {
+    type Item;
+}
+
+struct Container<T: Iterable<Item = impl Foo>> {
+    //~^ ERROR `impl Trait` not allowed
+    field: T
+}
+
+enum Enum<T: Iterable<Item = impl Foo>> {
+    //~^ ERROR `impl Trait` not allowed
+    A(T),
+}
+
+union Union<T: Iterable<Item = impl Foo> + Copy> {
+    //~^ ERROR `impl Trait` not allowed
+    x: T,
+}
+
+type Type<T: Iterable<Item = impl Foo>> = T;
+//~^ ERROR `impl Trait` not allowed
+
+fn main() {
+}

src/test/run-fail/rfc-1937-termination-trait/termination-trait-for-box-dyn-error.rs

@@ -0,0 +1,21 @@
+// Copyright 2018 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.
+
+// must-compile-successfully
+// failure-status: 1
+
+#![feature(dyn_trait)]
+
+use std::error::Error;
+use std::io;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    Err(Box::new(io::Error::new(io::ErrorKind::Other, "returned Box<dyn Error> from main()")))
+}

src/test/run-fail/rfc-1937-termination-trait/termination-trait-for-str.rs

@@ -0,0 +1,16 @@
+// Copyright 2018 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.
+
+// error-pattern: An error message for you
+// failure-status: 1
+
+fn main() -> Result<(), &'static str> {
+    Err("An error message for you")
+}

src/test/run-pass/issue-49556.rs

@@ -0,0 +1,22 @@
+// Copyright 2018 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.
+
+fn iter<'a>(data: &'a [usize]) -> impl Iterator<Item = usize> + 'a {
+    data.iter()
+        .map(
+            |x| x // fn(&'a usize) -> &'(ReScope) usize
+        )
+        .map(
+            |x| *x // fn(&'(ReScope) usize) -> usize
+        )
+}
+
+fn main() {
+}

src/test/run-pass/rfc-1937-termination-trait/termination-trait-for-box-dyn-error.rs

@@ -0,0 +1,17 @@
+// Copyright 2018 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.
+
+#![feature(dyn_trait)]
+
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    Ok(())
+}