Rollup of 8 pull requests

src/libcore/any.rs

@@ -446,14 +446,16 @@ impl TypeId {
 /// # Note
 ///
 /// This is intended for diagnostic use. The exact contents and format of the
-/// string are not specified, other than being a best-effort description of the
-/// type. For example, `type_name::<Option<String>>()` could return the
-/// `"Option<String>"` or `"std::option::Option<std::string::String>"`, but not
-/// `"foobar"`. In addition, the output may change between versions of the
-/// compiler.
+/// string returned are not specified, other than being a best-effort
+/// description of the type. For example, amongst the strings
+/// that `type_name::<Option<String>>()` might return are `"Option<String>"` and
+/// `"std::option::Option<std::string::String>"`.
 ///
-/// The type name should not be considered a unique identifier of a type;
-/// multiple types may share the same type name.
+/// The returned string must not be considered to be a unique identifier of a
+/// type as multiple types may map to the same type name. Similarly, there is no
+/// guarantee that all parts of a type will appear in the returned string: for
+/// example, lifetime specifiers are currently not included. In addition, the
+/// output may change between versions of the compiler.
 ///
 /// The current implementation uses the same infrastructure as compiler
 /// diagnostics and debuginfo, but this is not guaranteed.

src/librustc_codegen_ssa/back/write.rs

@@ -21,7 +21,7 @@ use rustc_errors::{DiagnosticId, FatalError, Handler, Level};
 use rustc_fs_util::link_or_copy;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
 use rustc_incremental::{
-    copy_cgu_workproducts_to_incr_comp_cache_dir, in_incr_comp_dir, in_incr_comp_dir_sess,
+    copy_cgu_workproduct_to_incr_comp_cache_dir, in_incr_comp_dir, in_incr_comp_dir_sess,
 };
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::cstore::EncodedMetadata;
@@ -465,17 +465,13 @@ fn copy_all_cgu_workproducts_to_incr_comp_cache_dir(
         return work_products;
     }
 
-    let _timer = sess.timer("incr_comp_copy_cgu_workproducts");
+    let _timer = sess.timer("copy_all_cgu_workproducts_to_incr_comp_cache_dir");
 
     for module in compiled_modules.modules.iter().filter(|m| m.kind == ModuleKind::Regular) {
-        let mut files = vec![];
-
-        if let Some(ref path) = module.object {
-            files.push(path.clone());
-        }
+        let path = module.object.as_ref().map(|path| path.clone());
 
         if let Some((id, product)) =
-            copy_cgu_workproducts_to_incr_comp_cache_dir(sess, &module.name, &files)
+            copy_cgu_workproduct_to_incr_comp_cache_dir(sess, &module.name, &path)
         {
             work_products.insert(id, product);
         }
@@ -817,7 +813,7 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
 ) -> Result<WorkItemResult<B>, FatalError> {
     let incr_comp_session_dir = cgcx.incr_comp_session_dir.as_ref().unwrap();
     let mut object = None;
-    for saved_file in &module.source.saved_files {
+    if let Some(saved_file) = module.source.saved_file {
         let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, Some(&module.name));
         object = Some(obj_out.clone());
         let source_file = in_incr_comp_dir(&incr_comp_session_dir, &saved_file);

src/librustc_codegen_ssa/debuginfo/type_names.rs

@@ -198,7 +198,6 @@ pub fn push_debuginfo_type_name<'tcx>(
         ty::Error
         | ty::Infer(_)
         | ty::Placeholder(..)
-        | ty::UnnormalizedProjection(..)
         | ty::Projection(..)
         | ty::Bound(..)
         | ty::Opaque(..)

src/librustc_error_codes/error_codes.rs

@@ -120,6 +120,7 @@ E0223: include_str!("./error_codes/E0223.md"),
 E0224: include_str!("./error_codes/E0224.md"),
 E0225: include_str!("./error_codes/E0225.md"),
 E0226: include_str!("./error_codes/E0226.md"),
+E0228: include_str!("./error_codes/E0228.md"),
 E0229: include_str!("./error_codes/E0229.md"),
 E0230: include_str!("./error_codes/E0230.md"),
 E0231: include_str!("./error_codes/E0231.md"),
@@ -482,7 +483,6 @@ E0753: include_str!("./error_codes/E0753.md"),
 //  E0218, // no associated type defined
 //  E0219, // associated type defined in higher-ranked supertrait
     E0227, // ambiguous lifetime bound, explicit lifetime bound required
-    E0228, // explicit lifetime bound required
 //  E0233,
 //  E0234,
 //  E0235, // structure constructor specifies a structure of type but

src/librustc_error_codes/error_codes/E0228.md

@@ -0,0 +1,40 @@
+The lifetime bound for this object type cannot be deduced from context and must
+be specified.
+
+Erroneous code example:
+
+```compile_fail,E0228
+trait Trait { }
+
+struct TwoBounds<'a, 'b, T: Sized + 'a + 'b> {
+    x: &'a i32,
+    y: &'b i32,
+    z: T,
+}
+
+type Foo<'a, 'b> = TwoBounds<'a, 'b, dyn Trait>;
+```
+
+When a trait object is used as a type argument of a generic type, Rust will try
+to infer its lifetime if unspecified. However, this isn't possible when the
+containing type has more than one lifetime bound.
+
+The above example can be resolved by either reducing the number of lifetime
+bounds to one or by making the trait object lifetime explicit, like so:
+
+```
+trait Trait { }
+
+struct TwoBounds<'a, 'b, T: Sized + 'a + 'b> {
+    x: &'a i32,
+    y: &'b i32,
+    z: T,
+}
+
+type Foo<'a, 'b> = TwoBounds<'a, 'b, dyn Trait + 'b>;
+```
+
+For more information, see [RFC 599] and its amendment [RFC 1156].
+
+[RFC 599]: https://github.com/rust-lang/rfcs/blob/master/text/0599-default-object-bound.md
+[RFC 1156]: https://github.com/rust-lang/rfcs/blob/master/text/1156-adjust-default-object-bounds.md

src/librustc_error_codes/error_codes/E0581.md

@@ -1,4 +1,4 @@
-In a `fn` type, a lifetime appears only in the return type,
+In a `fn` type, a lifetime appears only in the return type
 and not in the arguments types.
 
 Erroneous code example:
@@ -10,8 +10,11 @@ fn main() {
 }
 ```
 
-To fix this issue, either use the lifetime in the arguments, or use
-`'static`. Example:
+The problem here is that the lifetime isn't contrained by any of the arguments,
+making it impossible to determine how long it's supposed to live.
+
+To fix this issue, either use the lifetime in the arguments, or use the
+`'static` lifetime. Example:
 
 ```
 fn main() {

src/librustc_incremental/lib.rs

@@ -15,7 +15,7 @@ pub mod assert_module_sources;
 mod persist;
 
 pub use assert_dep_graph::assert_dep_graph;
-pub use persist::copy_cgu_workproducts_to_incr_comp_cache_dir;
+pub use persist::copy_cgu_workproduct_to_incr_comp_cache_dir;
 pub use persist::delete_workproduct_files;
 pub use persist::dep_graph_tcx_init;
 pub use persist::finalize_session_directory;

src/librustc_incremental/persist/load.rs

@@ -134,7 +134,7 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
 
             for swp in work_products {
                 let mut all_files_exist = true;
-                for file_name in swp.work_product.saved_files.iter() {
+                if let Some(ref file_name) = swp.work_product.saved_file {
                     let path = in_incr_comp_dir_sess(sess, file_name);
                     if !path.exists() {
                         all_files_exist = false;

src/librustc_incremental/persist/mod.rs

@@ -21,5 +21,5 @@ pub use load::LoadResult;
 pub use load::{load_dep_graph, DepGraphFuture};
 pub use save::save_dep_graph;
 pub use save::save_work_product_index;
-pub use work_product::copy_cgu_workproducts_to_incr_comp_cache_dir;
+pub use work_product::copy_cgu_workproduct_to_incr_comp_cache_dir;
 pub use work_product::delete_workproduct_files;

src/librustc_incremental/persist/save.rs

@@ -74,9 +74,9 @@ pub fn save_work_product_index(
         if !new_work_products.contains_key(id) {
             work_product::delete_workproduct_files(sess, wp);
             debug_assert!(
-                wp.saved_files
-                    .iter()
-                    .all(|file_name| { !in_incr_comp_dir_sess(sess, file_name).exists() })
+                wp.saved_file.as_ref().map_or(true, |file_name| {
+                    !in_incr_comp_dir_sess(sess, &file_name).exists()
+                })
             );
         }
     }
@@ -85,7 +85,7 @@ pub fn save_work_product_index(
     debug_assert!({
         new_work_products
             .iter()
-            .flat_map(|(_, wp)| wp.saved_files.iter())
+            .flat_map(|(_, wp)| wp.saved_file.iter())
             .map(|name| in_incr_comp_dir_sess(sess, name))
             .all(|path| path.exists())
     });

src/librustc_incremental/persist/work_product.rs

@@ -7,43 +7,41 @@ use rustc_session::Session;
 use std::fs as std_fs;
 use std::path::PathBuf;
 
-pub fn copy_cgu_workproducts_to_incr_comp_cache_dir(
+pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
     sess: &Session,
     cgu_name: &str,
-    files: &[PathBuf],
+    path: &Option<PathBuf>,
 ) -> Option<(WorkProductId, WorkProduct)> {
-    debug!("copy_cgu_workproducts_to_incr_comp_cache_dir({:?},{:?})", cgu_name, files);
+    debug!("copy_cgu_workproduct_to_incr_comp_cache_dir({:?},{:?})", cgu_name, path);
     sess.opts.incremental.as_ref()?;
 
-    let saved_files = files
-        .iter()
-        .map(|path| {
-            let file_name = format!("{}.o", cgu_name);
-            let path_in_incr_dir = in_incr_comp_dir_sess(sess, &file_name);
-            match link_or_copy(path, &path_in_incr_dir) {
-                Ok(_) => Some(file_name),
-                Err(err) => {
-                    sess.warn(&format!(
-                        "error copying object file `{}` \
-                                             to incremental directory as `{}`: {}",
-                        path.display(),
-                        path_in_incr_dir.display(),
-                        err
-                    ));
-                    None
-                }
+    let saved_file = if let Some(path) = path {
+        let file_name = format!("{}.o", cgu_name);
+        let path_in_incr_dir = in_incr_comp_dir_sess(sess, &file_name);
+        match link_or_copy(path, &path_in_incr_dir) {
+            Ok(_) => Some(file_name),
+            Err(err) => {
+                sess.warn(&format!(
+                    "error copying object file `{}` to incremental directory as `{}`: {}",
+                    path.display(),
+                    path_in_incr_dir.display(),
+                    err
+                ));
+                return None;
             }
-        })
-        .collect::<Option<Vec<_>>>()?;
+        }
+    } else {
+        None
+    };
 
-    let work_product = WorkProduct { cgu_name: cgu_name.to_string(), saved_files };
+    let work_product = WorkProduct { cgu_name: cgu_name.to_string(), saved_file };
 
     let work_product_id = WorkProductId::from_cgu_name(cgu_name);
     Some((work_product_id, work_product))
 }
 
 pub fn delete_workproduct_files(sess: &Session, work_product: &WorkProduct) {
-    for file_name in &work_product.saved_files {
+    if let Some(ref file_name) = work_product.saved_file {
         let path = in_incr_comp_dir_sess(sess, file_name);
         match std_fs::remove_file(&path) {
             Ok(()) => {}

src/librustc_infer/infer/canonical/canonicalizer.rs

@@ -415,7 +415,6 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> {
             | ty::Never
             | ty::Tuple(..)
             | ty::Projection(..)
-            | ty::UnnormalizedProjection(..)
             | ty::Foreign(..)
             | ty::Param(..)
             | ty::Opaque(..) => {

src/librustc_infer/infer/error_reporting/need_type_info.rs

@@ -554,7 +554,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     let output = bound_output.skip_binder();
                     err.span_label(e.span, &format!("this method call resolves to `{:?}`", output));
                     let kind = &output.kind;
-                    if let ty::Projection(proj) | ty::UnnormalizedProjection(proj) = kind {
+                    if let ty::Projection(proj) = kind {
                         if let Some(span) = self.tcx.hir().span_if_local(proj.item_def_id) {
                             err.span_label(span, &format!("`{:?}` defined here", output));
                         }

src/librustc_infer/infer/freshen.rs

@@ -204,7 +204,6 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> {
             | ty::Never
             | ty::Tuple(..)
             | ty::Projection(..)
-            | ty::UnnormalizedProjection(..)
             | ty::Foreign(..)
             | ty::Param(..)
             | ty::Closure(..)

src/librustc_lint/types.rs

@@ -888,7 +888,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
             | ty::Placeholder(..)
-            | ty::UnnormalizedProjection(..)
             | ty::Projection(..)
             | ty::Opaque(..)
             | ty::FnDef(..) => bug!("unexpected type in foreign function: {:?}", ty),

src/librustc_middle/mir/mono.rs

@@ -239,6 +239,9 @@ pub struct CodegenUnit<'tcx> {
     size_estimate: Option<usize>,
 }
 
+/// Specifies the linkage type for a `MonoItem`.
+///
+/// See https://llvm.org/docs/LangRef.html#linkage-types for more details about these variants.
 #[derive(Copy, Clone, PartialEq, Debug, RustcEncodable, RustcDecodable, HashStable)]
 pub enum Linkage {
     External,

src/librustc_middle/traits/query.rs

@@ -255,8 +255,6 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
         | ty::Infer(_)
         | ty::Bound(..)
         | ty::Generator(..) => false,
-
-        ty::UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
     }
 }
 

src/librustc_middle/ty/context.rs

@@ -1878,7 +1878,6 @@ impl<'tcx> TyCtxt<'tcx> {
             Bound,
             Param,
             Infer,
-            UnnormalizedProjection,
             Projection,
             Opaque,
             Foreign

src/librustc_middle/ty/error.rs

@@ -284,7 +284,6 @@ impl<'tcx> ty::TyS<'tcx> {
             ty::Infer(ty::FreshIntTy(_)) => "fresh integral type".into(),
             ty::Infer(ty::FreshFloatTy(_)) => "fresh floating-point type".into(),
             ty::Projection(_) => "associated type".into(),
-            ty::UnnormalizedProjection(_) => "non-normalized associated type".into(),
             ty::Param(p) => format!("type parameter `{}`", p).into(),
             ty::Opaque(..) => "opaque type".into(),
             ty::Error => "type error".into(),
@@ -323,7 +322,6 @@ impl<'tcx> ty::TyS<'tcx> {
             ty::Placeholder(..) => "higher-ranked type".into(),
             ty::Bound(..) => "bound type variable".into(),
             ty::Projection(_) => "associated type".into(),
-            ty::UnnormalizedProjection(_) => "associated type".into(),
             ty::Param(_) => "type parameter".into(),
             ty::Opaque(..) => "opaque type".into(),
         }

src/librustc_middle/ty/fast_reject.rs

@@ -90,7 +90,6 @@ pub fn simplify_type(
         ty::Never => Some(NeverSimplifiedType),
         ty::Tuple(ref tys) => Some(TupleSimplifiedType(tys.len())),
         ty::FnPtr(ref f) => Some(FunctionSimplifiedType(f.skip_binder().inputs().len())),
-        ty::UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
         ty::Projection(_) | ty::Param(_) => {
             if can_simplify_params {
                 // In normalized types, projections don't unify with

src/librustc_middle/ty/flags.rs

@@ -121,11 +121,6 @@ impl FlagComputation {
                 self.add_projection_ty(data);
             }
 
-            &ty::UnnormalizedProjection(ref data) => {
-                self.add_flags(TypeFlags::HAS_TY_PROJECTION);
-                self.add_projection_ty(data);
-            }
-
             &ty::Opaque(_, substs) => {
                 self.add_flags(TypeFlags::HAS_TY_OPAQUE);
                 self.add_substs(substs);

src/librustc_middle/ty/layout.rs

@@ -1241,11 +1241,9 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
                 tcx.layout_raw(param_env.and(normalized))?
             }
 
-            ty::Bound(..)
-            | ty::Placeholder(..)
-            | ty::UnnormalizedProjection(..)
-            | ty::GeneratorWitness(..)
-            | ty::Infer(_) => bug!("Layout::compute: unexpected type `{}`", ty),
+            ty::Bound(..) | ty::Placeholder(..) | ty::GeneratorWitness(..) | ty::Infer(_) => {
+                bug!("Layout::compute: unexpected type `{}`", ty)
+            }
 
             ty::Param(_) | ty::Error => {
                 return Err(LayoutError::Unknown(ty));
@@ -2138,7 +2136,6 @@ where
             }
 
             ty::Projection(_)
-            | ty::UnnormalizedProjection(..)
             | ty::Bound(..)
             | ty::Placeholder(..)
             | ty::Opaque(..)