Rollup of 5 pull requests

compiler/rustc_ast_lowering/src/lib.rs

@@ -1845,11 +1845,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             GenericParamKind::Lifetime => {
                 // AST resolution emitted an error on those parameters, so we lower them using
                 // `ParamName::Error`.
+                let ident = self.lower_ident(param.ident);
                 let param_name =
                     if let Some(LifetimeRes::Error) = self.resolver.get_lifetime_res(param.id) {
-                        ParamName::Error
+                        ParamName::Error(ident)
                     } else {
-                        let ident = self.lower_ident(param.ident);
                         ParamName::Plain(ident)
                     };
                 let kind =

compiler/rustc_hir/src/hir.rs

@@ -52,6 +52,13 @@ pub enum ParamName {
     /// Some user-given name like `T` or `'x`.
     Plain(Ident),
 
+    /// Indicates an illegal name was given and an error has been
+    /// reported (so we should squelch other derived errors).
+    ///
+    /// Occurs when, e.g., `'_` is used in the wrong place, or a
+    /// lifetime name is duplicated.
+    Error(Ident),
+
     /// Synthetic name generated when user elided a lifetime in an impl header.
     ///
     /// E.g., the lifetimes in cases like these:
@@ -67,18 +74,13 @@ pub enum ParamName {
     /// where `'f` is something like `Fresh(0)`. The indices are
     /// unique per impl, but not necessarily continuous.
     Fresh,
-
-    /// Indicates an illegal name was given and an error has been
-    /// reported (so we should squelch other derived errors). Occurs
-    /// when, e.g., `'_` is used in the wrong place.
-    Error,
 }
 
 impl ParamName {
     pub fn ident(&self) -> Ident {
         match *self {
-            ParamName::Plain(ident) => ident,
-            ParamName::Fresh | ParamName::Error => Ident::with_dummy_span(kw::UnderscoreLifetime),
+            ParamName::Plain(ident) | ParamName::Error(ident) => ident,
+            ParamName::Fresh => Ident::with_dummy_span(kw::UnderscoreLifetime),
         }
     }
 }

compiler/rustc_hir/src/intravisit.rs

@@ -928,8 +928,8 @@ pub fn walk_generic_param<'v, V: Visitor<'v>>(
 ) -> V::Result {
     try_visit!(visitor.visit_id(param.hir_id));
     match param.name {
-        ParamName::Plain(ident) => try_visit!(visitor.visit_ident(ident)),
-        ParamName::Error | ParamName::Fresh => {}
+        ParamName::Plain(ident) | ParamName::Error(ident) => try_visit!(visitor.visit_ident(ident)),
+        ParamName::Fresh => {}
     }
     match param.kind {
         GenericParamKind::Lifetime { .. } => {}

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -2007,7 +2007,10 @@ fn check_variances_for_type_defn<'tcx>(
         }
 
         match hir_param.name {
-            hir::ParamName::Error => {}
+            hir::ParamName::Error(_) => {
+                // Don't report a bivariance error for a lifetime that isn't
+                // even valid to name.
+            }
             _ => {
                 let has_explicit_bounds = explicitly_bounded_params.contains(&parameter);
                 report_bivariance(tcx, hir_param, has_explicit_bounds, item);

compiler/rustc_hir_typeck/src/callee.rs

@@ -7,7 +7,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::{self as hir, HirId, LangItem};
 use rustc_hir_analysis::autoderef::Autoderef;
 use rustc_infer::infer;
-use rustc_infer::traits::{self, Obligation, ObligationCause, ObligationCauseCode};
+use rustc_infer::traits::{Obligation, ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
 };
@@ -512,7 +512,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.register_bound(
                     ty,
                     self.tcx.require_lang_item(hir::LangItem::Tuple, Some(sp)),
-                    traits::ObligationCause::new(sp, self.body_id, ObligationCauseCode::RustCall),
+                    self.cause(sp, ObligationCauseCode::RustCall),
                 );
                 self.require_type_is_sized(ty, sp, ObligationCauseCode::RustCall);
             } else {

compiler/rustc_hir_typeck/src/coercion.rs

@@ -580,11 +580,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         let mut selcx = traits::SelectionContext::new(self);
 
         // Create an obligation for `Source: CoerceUnsized<Target>`.
-        let cause =
-            ObligationCause::new(self.cause.span, self.body_id, ObligationCauseCode::Coercion {
-                source,
-                target,
-            });
+        let cause = self.cause(self.cause.span, ObligationCauseCode::Coercion { source, target });
 
         // Use a FIFO queue for this custom fulfillment procedure.
         //

compiler/rustc_hir_typeck/src/expr.rs

@@ -22,7 +22,6 @@ use rustc_hir::{ExprKind, HirId, QPath};
 use rustc_hir_analysis::hir_ty_lowering::{FeedConstTy, HirTyLowerer as _};
 use rustc_infer::infer;
 use rustc_infer::infer::{DefineOpaqueTypes, InferOk};
-use rustc_infer::traits::ObligationCause;
 use rustc_infer::traits::query::NoSolution;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AllowTwoPhase};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
@@ -1174,9 +1173,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         for err in errors {
             let cause = &mut err.obligation.cause;
             if let ObligationCauseCode::OpaqueReturnType(None) = cause.code() {
-                let new_cause = ObligationCause::new(
+                let new_cause = self.cause(
                     cause.span,
-                    cause.body_id,
                     ObligationCauseCode::OpaqueReturnType(Some((return_expr_ty, hir_id))),
                 );
                 *cause = new_cause;
@@ -3856,7 +3854,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // Enums are anyway always sized. But just to safeguard against future
                     // language extensions, let's double-check.
-                    self.require_type_is_sized(field_ty, expr.span, ObligationCauseCode::Misc);
+                    self.require_type_is_sized(
+                        field_ty,
+                        expr.span,
+                        ObligationCauseCode::FieldSized {
+                            adt_kind: AdtKind::Enum,
+                            span: self.tcx.def_span(field.did),
+                            last: false,
+                        },
+                    );
 
                     if field.vis.is_accessible_from(sub_def_scope, self.tcx) {
                         self.tcx.check_stability(field.did, Some(expr.hir_id), expr.span, None);
@@ -3884,11 +3890,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let field_ty = self.field_ty(expr.span, field, args);
 
                         if self.tcx.features().offset_of_slice() {
-                            self.require_type_has_static_alignment(
-                                field_ty,
-                                expr.span,
-                                ObligationCauseCode::Misc,
-                            );
+                            self.require_type_has_static_alignment(field_ty, expr.span);
                         } else {
                             self.require_type_is_sized(
                                 field_ty,
@@ -3917,11 +3919,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     {
                         if let Some(&field_ty) = tys.get(index) {
                             if self.tcx.features().offset_of_slice() {
-                                self.require_type_has_static_alignment(
-                                    field_ty,
-                                    expr.span,
-                                    ObligationCauseCode::Misc,
-                                );
+                                self.require_type_has_static_alignment(field_ty, expr.span);
                             } else {
                                 self.require_type_is_sized(
                                     field_ty,

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -384,7 +384,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         code: traits::ObligationCauseCode<'tcx>,
         def_id: DefId,
     ) {
-        self.register_bound(ty, def_id, traits::ObligationCause::new(span, self.body_id, code));
+        self.register_bound(ty, def_id, self.cause(span, code));
     }
 
     pub(crate) fn require_type_is_sized(
@@ -410,12 +410,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub(crate) fn require_type_has_static_alignment(
-        &self,
-        ty: Ty<'tcx>,
-        span: Span,
-        code: traits::ObligationCauseCode<'tcx>,
-    ) {
+    pub(crate) fn require_type_has_static_alignment(&self, ty: Ty<'tcx>, span: Span) {
         if !ty.references_error() {
             let tail = self.tcx.struct_tail_raw(
                 ty,
@@ -434,7 +429,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             } else {
                 // We can't be sure, let's required full `Sized`.
                 let lang_item = self.tcx.require_lang_item(LangItem::Sized, None);
-                self.require_type_meets(ty, span, code, lang_item);
+                self.require_type_meets(ty, span, ObligationCauseCode::Misc, lang_item);
             }
         }
     }
@@ -572,7 +567,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         code: traits::ObligationCauseCode<'tcx>,
     ) {
         // WF obligations never themselves fail, so no real need to give a detailed cause:
-        let cause = traits::ObligationCause::new(span, self.body_id, code);
+        let cause = self.cause(span, code);
         self.register_predicate(traits::Obligation::new(
             self.tcx,
             cause,
@@ -1426,9 +1421,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let bounds = self.instantiate_bounds(span, def_id, args);
 
         for obligation in traits::predicates_for_generics(
-            |idx, predicate_span| {
-                traits::ObligationCause::new(span, self.body_id, code(idx, predicate_span))
-            },
+            |idx, predicate_span| self.cause(span, code(idx, predicate_span)),
             param_env,
             bounds,
         ) {
@@ -1561,7 +1554,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         query_result: &Canonical<'tcx, QueryResponse<'tcx, Ty<'tcx>>>,
     ) -> InferResult<'tcx, Ty<'tcx>> {
         self.instantiate_query_response_and_region_obligations(
-            &traits::ObligationCause::misc(span, self.body_id),
+            &self.misc(span),
             self.param_env,
             original_values,
             query_result,

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -207,7 +207,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.register_wf_obligation(
                 fn_input_ty.into(),
                 arg_expr.span,
-                ObligationCauseCode::Misc,
+                ObligationCauseCode::WellFormed(None),
             );
         }
 

compiler/rustc_hir_typeck/src/method/confirm.rs

@@ -601,7 +601,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
                     self.call_expr.hir_id,
                     idx,
                 );
-                traits::ObligationCause::new(self.span, self.body_id, code)
+                self.cause(self.span, code)
             },
             self.param_env,
             method_predicates,

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -1739,8 +1739,8 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         &self,
         trait_ref: ty::TraitRef<'tcx>,
     ) -> traits::SelectionResult<'tcx, traits::Selection<'tcx>> {
-        let cause = traits::ObligationCause::misc(self.span, self.body_id);
-        let obligation = traits::Obligation::new(self.tcx, cause, self.param_env, trait_ref);
+        let obligation =
+            traits::Obligation::new(self.tcx, self.misc(self.span), self.param_env, trait_ref);
         traits::SelectionContext::new(self).select(&obligation)
     }
 
@@ -1841,7 +1841,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                                 self.scope_expr_id,
                                 idx,
                             );
-                            ObligationCause::new(self.span, self.body_id, code)
+                            self.cause(self.span, code)
                         },
                         self.param_env,
                         impl_bounds,

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -105,8 +105,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return false;
         };
         let trait_ref = ty::TraitRef::new(self.tcx, into_iterator_trait, [ty]);
-        let cause = ObligationCause::new(span, self.body_id, ObligationCauseCode::Misc);
-        let obligation = Obligation::new(self.tcx, cause, self.param_env, trait_ref);
+        let obligation = Obligation::new(self.tcx, self.misc(span), self.param_env, trait_ref);
         if !self.predicate_must_hold_modulo_regions(&obligation) {
             return false;
         }
@@ -3489,7 +3488,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let pred = ty::TraitRef::new(self.tcx, unpin_trait, [*rcvr_ty]);
                 let unpin = self.predicate_must_hold_considering_regions(&Obligation::new(
                     self.tcx,
-                    ObligationCause::misc(rcvr.span, self.body_id),
+                    self.misc(rcvr.span),
                     self.param_env,
                     pred,
                 ));

library/core/src/cmp.rs

@@ -796,7 +796,7 @@ impl<T: Clone> Clone for Reverse<T> {
 /// }
 ///
 /// impl Ord for Character {
-///     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+///     fn cmp(&self, other: &Self) -> Ordering {
 ///         self.experience
 ///             .cmp(&other.experience)
 ///             .then(self.health.cmp(&other.health))

src/bootstrap/src/core/build_steps/doc.rs

@@ -18,19 +18,10 @@ use crate::core::builder::{
     self, Alias, Builder, Compiler, Kind, RunConfig, ShouldRun, Step, crate_description,
 };
 use crate::core::config::{Config, TargetSelection};
-use crate::utils::helpers::{symlink_dir, t, up_to_date};
-
-macro_rules! submodule_helper {
-    ($path:expr, submodule) => {
-        $path
-    };
-    ($path:expr, submodule = $submodule:literal) => {
-        $submodule
-    };
-}
+use crate::helpers::{is_path_in_submodule, symlink_dir, t, up_to_date};
 
 macro_rules! book {
-    ($($name:ident, $path:expr, $book_name:expr, $lang:expr $(, submodule $(= $submodule:literal)? )? ;)+) => {
+    ($($name:ident, $path:expr, $book_name:expr, $lang:expr ;)+) => {
         $(
             #[derive(Debug, Clone, Hash, PartialEq, Eq)]
         pub struct $name {
@@ -53,10 +44,10 @@ macro_rules! book {
             }
 
             fn run(self, builder: &Builder<'_>) {
-                $(
-                    let path = submodule_helper!( $path, submodule $( = $submodule )? );
-                    builder.require_submodule(path, None);
-                )?
+                if is_path_in_submodule(&builder, $path) {
+                    builder.require_submodule($path, None);
+                }
+
                 builder.ensure(RustbookSrc {
                     target: self.target,
                     name: $book_name.to_owned(),
@@ -77,12 +68,12 @@ macro_rules! book {
 // FIXME: Make checking for a submodule automatic somehow (maybe by having a list of all submodules
 // and checking against it?).
 book!(
-    CargoBook, "src/tools/cargo/src/doc", "cargo", &[], submodule = "src/tools/cargo";
+    CargoBook, "src/tools/cargo/src/doc", "cargo", &[];
     ClippyBook, "src/tools/clippy/book", "clippy", &[];
-    EditionGuide, "src/doc/edition-guide", "edition-guide", &[], submodule;
-    EmbeddedBook, "src/doc/embedded-book", "embedded-book", &[], submodule;
-    Nomicon, "src/doc/nomicon", "nomicon", &[], submodule;
-    RustByExample, "src/doc/rust-by-example", "rust-by-example", &["ja", "zh"], submodule;
+    EditionGuide, "src/doc/edition-guide", "edition-guide", &[];
+    EmbeddedBook, "src/doc/embedded-book", "embedded-book", &[];
+    Nomicon, "src/doc/nomicon", "nomicon", &[];
+    RustByExample, "src/doc/rust-by-example", "rust-by-example", &["ja", "zh"];
     RustdocBook, "src/doc/rustdoc", "rustdoc", &[];
     StyleGuide, "src/doc/style-guide", "style-guide", &[];
 );
@@ -910,7 +901,6 @@ macro_rules! tool_doc {
         $(rustc_tool = $rustc_tool:literal, )?
         $(is_library = $is_library:expr,)?
         $(crates = $crates:expr)?
-        $(, submodule $(= $submodule:literal)? )?
        ) => {
         #[derive(Debug, Clone, Hash, PartialEq, Eq)]
         pub struct $tool {
@@ -938,14 +928,12 @@ macro_rules! tool_doc {
             /// we do not merge it with the other documentation from std, test and
             /// proc_macros. This is largely just a wrapper around `cargo doc`.
             fn run(self, builder: &Builder<'_>) {
-                let source_type = SourceType::InTree;
-                $(
-                    let _ = source_type; // silence the "unused variable" warning
-                    let source_type = SourceType::Submodule;
+                let mut source_type = SourceType::InTree;
 
-                    let path = submodule_helper!( $path, submodule $( = $submodule )? );
-                    builder.require_submodule(path, None);
-                )?
+                if is_path_in_submodule(&builder, $path) {
+                    source_type = SourceType::Submodule;
+                    builder.require_submodule($path, None);
+                }
 
                 let stage = builder.top_stage;
                 let target = self.target;
@@ -1054,8 +1042,7 @@ tool_doc!(
         "crates-io",
         "mdman",
         "rustfix",
-    ],
-    submodule = "src/tools/cargo"
+    ]
 );
 tool_doc!(Tidy, "src/tools/tidy", rustc_tool = false, crates = ["tidy"]);
 tool_doc!(

src/bootstrap/src/utils/helpers.rs

@@ -60,6 +60,12 @@ pub fn is_dylib(path: &Path) -> bool {
     })
 }
 
+/// Returns `true` if the given path is part of a submodule.
+pub fn is_path_in_submodule(builder: &Builder<'_>, path: &str) -> bool {
+    let submodule_paths = build_helper::util::parse_gitmodules(&builder.src);
+    submodule_paths.iter().any(|submodule_path| path.starts_with(submodule_path))
+}
+
 fn is_aix_shared_archive(path: &Path) -> bool {
     let file = match fs::File::open(path) {
         Ok(file) => file,