Auto merge of rust-lang#88371 - Manishearth:rollup-pkkjsme, r=Manishearth

Rollup of 11 pull requests

Successful merges:

 - rust-lang#87832 (Fix debugger stepping behavior with `match` expressions)
 - rust-lang#88123 (Make spans for tuple patterns in E0023 more precise)
 - rust-lang#88215 (Reland rust-lang#83738: "rustdoc: Don't load all extern crates unconditionally")
 - rust-lang#88216 (Don't stabilize creation of TryReserveError instances)
 - rust-lang#88270 (Handle type ascription type ops in NLL HRTB diagnostics)
 - rust-lang#88289 (Fixes for LLVM change 0f45c16)
 - rust-lang#88320 (type_implements_trait consider obligation failure on overflow)
 - rust-lang#88332 (Add argument types tait tests)
 - rust-lang#88340 (Add `c_size_t` and `c_ssize_t` to `std::os::raw`.)
 - rust-lang#88346 (Revert "Add type of a let tait test impl trait straight in let")
 - rust-lang#88348 (Add field types tait tests)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_hir/src/hir.rs

@@ -3183,6 +3183,20 @@ pub enum Node<'hir> {
 }
 
 impl<'hir> Node<'hir> {
+    /// Get the identifier of this `Node`, if applicable.
+    ///
+    /// # Edge cases
+    ///
+    /// Calling `.ident()` on a [`Node::Ctor`] will return `None`
+    /// because `Ctor`s do not have identifiers themselves.
+    /// Instead, call `.ident()` on the parent struct/variant, like so:
+    ///
+    /// ```ignore (illustrative)
+    /// ctor
+    ///     .ctor_hir_id()
+    ///     .and_then(|ctor_id| tcx.hir().find(tcx.hir().get_parent_node(ctor_id)))
+    ///     .and_then(|parent| parent.ident())
+    /// ```
     pub fn ident(&self) -> Option<Ident> {
         match self {
             Node::TraitItem(TraitItem { ident, .. })
@@ -3191,8 +3205,25 @@ impl<'hir> Node<'hir> {
             | Node::Field(FieldDef { ident, .. })
             | Node::Variant(Variant { ident, .. })
             | Node::MacroDef(MacroDef { ident, .. })
-            | Node::Item(Item { ident, .. }) => Some(*ident),
-            _ => None,
+            | Node::Item(Item { ident, .. })
+            | Node::PathSegment(PathSegment { ident, .. }) => Some(*ident),
+            Node::Lifetime(lt) => Some(lt.name.ident()),
+            Node::GenericParam(p) => Some(p.name.ident()),
+            Node::Param(..)
+            | Node::AnonConst(..)
+            | Node::Expr(..)
+            | Node::Stmt(..)
+            | Node::Block(..)
+            | Node::Ctor(..)
+            | Node::Pat(..)
+            | Node::Binding(..)
+            | Node::Arm(..)
+            | Node::Local(..)
+            | Node::Visibility(..)
+            | Node::Crate(..)
+            | Node::Ty(..)
+            | Node::TraitRef(..)
+            | Node::Infer(..) => None,
         }
     }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -270,34 +270,30 @@ extern "C" void LLVMRustAddFunctionAttribute(LLVMValueRef Fn, unsigned Index,
                                              LLVMRustAttribute RustAttr) {
   Function *A = unwrap<Function>(Fn);
   Attribute Attr = Attribute::get(A->getContext(), fromRust(RustAttr));
-  AttrBuilder B(Attr);
-  A->addAttributes(Index, B);
+  A->addAttribute(Index, Attr);
 }
 
 extern "C" void LLVMRustAddAlignmentAttr(LLVMValueRef Fn,
                                          unsigned Index,
                                          uint32_t Bytes) {
   Function *A = unwrap<Function>(Fn);
-  AttrBuilder B;
-  B.addAlignmentAttr(Bytes);
-  A->addAttributes(Index, B);
+  A->addAttribute(Index, Attribute::getWithAlignment(
+      A->getContext(), llvm::Align(Bytes)));
 }
 
 extern "C" void LLVMRustAddDereferenceableAttr(LLVMValueRef Fn, unsigned Index,
                                                uint64_t Bytes) {
   Function *A = unwrap<Function>(Fn);
-  AttrBuilder B;
-  B.addDereferenceableAttr(Bytes);
-  A->addAttributes(Index, B);
+  A->addAttribute(Index, Attribute::getWithDereferenceableBytes(A->getContext(),
+                                                                Bytes));
 }
 
 extern "C" void LLVMRustAddDereferenceableOrNullAttr(LLVMValueRef Fn,
                                                      unsigned Index,
                                                      uint64_t Bytes) {
   Function *A = unwrap<Function>(Fn);
-  AttrBuilder B;
-  B.addDereferenceableOrNullAttr(Bytes);
-  A->addAttributes(Index, B);
+  A->addAttribute(Index, Attribute::getWithDereferenceableOrNullBytes(
+      A->getContext(), Bytes));
 }
 
 extern "C" void LLVMRustAddByValAttr(LLVMValueRef Fn, unsigned Index,
@@ -323,9 +319,8 @@ extern "C" void LLVMRustAddFunctionAttrStringValue(LLVMValueRef Fn,
                                                    const char *Name,
                                                    const char *Value) {
   Function *F = unwrap<Function>(Fn);
-  AttrBuilder B;
-  B.addAttribute(Name, Value);
-  F->addAttributes(Index, B);
+  F->addAttribute(Index, Attribute::get(
+      F->getContext(), StringRef(Name), StringRef(Value)));
 }
 
 extern "C" void LLVMRustRemoveFunctionAttributes(LLVMValueRef Fn,

compiler/rustc_mir/src/borrow_check/diagnostics/bound_region_errors.rs

@@ -9,7 +9,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_span::Span;
 use rustc_trait_selection::traits::query::type_op;
 use rustc_trait_selection::traits::{SelectionContext, TraitEngineExt as _};
-use rustc_traits::type_op_prove_predicate_with_span;
+use rustc_traits::{type_op_ascribe_user_type_with_span, type_op_prove_predicate_with_span};
 
 use std::fmt;
 use std::rc::Rc;
@@ -104,10 +104,11 @@ impl<'tcx, T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx> ToUniverseInfo<'t
 impl<'tcx> ToUniverseInfo<'tcx>
     for Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::AscribeUserType<'tcx>>>
 {
-    fn to_universe_info(self, _base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
-        // Ascribe user type isn't usually called on types that have different
-        // bound regions.
-        UniverseInfo::other()
+    fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
+        UniverseInfo(UniverseInfoInner::TypeOp(Rc::new(AscribeUserTypeQuery {
+            canonical_query: self,
+            base_universe,
+        })))
     }
 }
 
@@ -267,6 +268,37 @@ where
     }
 }
 
+struct AscribeUserTypeQuery<'tcx> {
+    canonical_query: Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::AscribeUserType<'tcx>>>,
+    base_universe: ty::UniverseIndex,
+}
+
+impl TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
+    fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
+        // FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
+        // and is only the fallback when the nice error fails. Consider improving this some more.
+        tcx.sess.struct_span_err(span, "higher-ranked lifetime error")
+    }
+
+    fn base_universe(&self) -> ty::UniverseIndex {
+        self.base_universe
+    }
+
+    fn nice_error(
+        &self,
+        tcx: TyCtxt<'tcx>,
+        span: Span,
+        placeholder_region: ty::Region<'tcx>,
+        error_region: Option<ty::Region<'tcx>>,
+    ) -> Option<DiagnosticBuilder<'tcx>> {
+        tcx.infer_ctxt().enter_with_canonical(span, &self.canonical_query, |ref infcx, key, _| {
+            let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
+            type_op_ascribe_user_type_with_span(infcx, &mut *fulfill_cx, key, Some(span)).ok()?;
+            try_extract_error_from_fulfill_cx(fulfill_cx, infcx, placeholder_region, error_region)
+        })
+    }
+}
+
 fn try_extract_error_from_fulfill_cx<'tcx>(
     mut fulfill_cx: Box<dyn TraitEngine<'tcx> + 'tcx>,
     infcx: &InferCtxt<'_, 'tcx>,

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -21,7 +21,7 @@ use rustc_middle::mir::*;
 use rustc_middle::thir::{self, *};
 use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty};
 use rustc_span::symbol::Symbol;
-use rustc_span::Span;
+use rustc_span::{BytePos, Pos, Span};
 use rustc_target::abi::VariantIdx;
 use smallvec::{smallvec, SmallVec};
 
@@ -143,8 +143,15 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let mut candidates =
             arm_candidates.iter_mut().map(|(_, candidate)| candidate).collect::<Vec<_>>();
 
-        let fake_borrow_temps =
-            self.lower_match_tree(block, scrutinee_span, match_has_guard, &mut candidates);
+        let match_start_span = span.shrink_to_lo().to(scrutinee.span);
+
+        let fake_borrow_temps = self.lower_match_tree(
+            block,
+            scrutinee_span,
+            match_start_span,
+            match_has_guard,
+            &mut candidates,
+        );
 
         self.lower_match_arms(
             destination,
@@ -224,6 +231,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         &mut self,
         block: BasicBlock,
         scrutinee_span: Span,
+        match_start_span: Span,
         match_has_guard: bool,
         candidates: &mut [&mut Candidate<'pat, 'tcx>],
     ) -> Vec<(Place<'tcx>, Local)> {
@@ -236,7 +244,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         // This will generate code to test scrutinee_place and
         // branch to the appropriate arm block
-        self.match_candidates(scrutinee_span, block, &mut otherwise, candidates, &mut fake_borrows);
+        self.match_candidates(
+            match_start_span,
+            scrutinee_span,
+            block,
+            &mut otherwise,
+            candidates,
+            &mut fake_borrows,
+        );
 
         if let Some(otherwise_block) = otherwise {
             // See the doc comment on `match_candidates` for why we may have an
@@ -339,8 +354,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         // all the arm blocks will rejoin here
         let end_block = self.cfg.start_new_block();
 
+        let end_brace = self.source_info(
+            outer_source_info.span.with_lo(outer_source_info.span.hi() - BytePos::from_usize(1)),
+        );
         for arm_block in arm_end_blocks {
-            self.cfg.goto(unpack!(arm_block), outer_source_info, end_block);
+            let block = &self.cfg.basic_blocks[arm_block.0];
+            let last_location = block.statements.last().map(|s| s.source_info);
+
+            self.cfg.goto(unpack!(arm_block), last_location.unwrap_or(end_brace), end_block);
         }
 
         self.source_scope = outer_source_info.scope;
@@ -533,8 +554,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         set_match_place: bool,
     ) -> BlockAnd<()> {
         let mut candidate = Candidate::new(initializer.clone(), &irrefutable_pat, false);
-        let fake_borrow_temps =
-            self.lower_match_tree(block, irrefutable_pat.span, false, &mut [&mut candidate]);
+        let fake_borrow_temps = self.lower_match_tree(
+            block,
+            irrefutable_pat.span,
+            irrefutable_pat.span,
+            false,
+            &mut [&mut candidate],
+        );
         // For matches and function arguments, the place that is being matched
         // can be set when creating the variables. But the place for
         // let PATTERN = ... might not even exist until we do the assignment.
@@ -993,6 +1019,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     fn match_candidates<'pat>(
         &mut self,
         span: Span,
+        scrutinee_span: Span,
         start_block: BasicBlock,
         otherwise_block: &mut Option<BasicBlock>,
         candidates: &mut [&mut Candidate<'pat, 'tcx>],
@@ -1022,6 +1049,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 }
                 self.match_simplified_candidates(
                     span,
+                    scrutinee_span,
                     start_block,
                     otherwise_block,
                     &mut *new_candidates,
@@ -1030,6 +1058,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             } else {
                 self.match_simplified_candidates(
                     span,
+                    scrutinee_span,
                     start_block,
                     otherwise_block,
                     candidates,
@@ -1042,6 +1071,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     fn match_simplified_candidates(
         &mut self,
         span: Span,
+        scrutinee_span: Span,
         start_block: BasicBlock,
         otherwise_block: &mut Option<BasicBlock>,
         candidates: &mut [&mut Candidate<'_, 'tcx>],
@@ -1087,6 +1117,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         // Test for the remaining candidates.
         self.test_candidates_with_or(
             span,
+            scrutinee_span,
             unmatched_candidates,
             block,
             otherwise_block,
@@ -1257,6 +1288,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     fn test_candidates_with_or(
         &mut self,
         span: Span,
+        scrutinee_span: Span,
         candidates: &mut [&mut Candidate<'_, 'tcx>],
         block: BasicBlock,
         otherwise_block: &mut Option<BasicBlock>,
@@ -1269,7 +1301,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         match *first_candidate.match_pairs[0].pattern.kind {
             PatKind::Or { .. } => (),
             _ => {
-                self.test_candidates(span, candidates, block, otherwise_block, fake_borrows);
+                self.test_candidates(
+                    span,
+                    scrutinee_span,
+                    candidates,
+                    block,
+                    otherwise_block,
+                    fake_borrows,
+                );
                 return;
             }
         }
@@ -1302,6 +1341,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         self.match_candidates(
             span,
+            scrutinee_span,
             remainder_start,
             otherwise_block,
             remaining_candidates,
@@ -1330,6 +1370,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             otherwise
         };
         self.match_candidates(
+            or_span,
             or_span,
             candidate.pre_binding_block.unwrap(),
             otherwise,
@@ -1497,6 +1538,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     fn test_candidates<'pat, 'b, 'c>(
         &mut self,
         span: Span,
+        scrutinee_span: Span,
         mut candidates: &'b mut [&'c mut Candidate<'pat, 'tcx>],
         block: BasicBlock,
         otherwise_block: &mut Option<BasicBlock>,
@@ -1591,6 +1633,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         let candidate_start = this.cfg.start_new_block();
                         this.match_candidates(
                             span,
+                            scrutinee_span,
                             candidate_start,
                             remainder_start,
                             &mut *candidates,
@@ -1607,6 +1650,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 let remainder_start = remainder_start.unwrap_or_else(|| this.cfg.start_new_block());
                 this.match_candidates(
                     span,
+                    scrutinee_span,
                     remainder_start,
                     otherwise_block,
                     candidates,
@@ -1617,7 +1661,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             target_blocks
         };
 
-        self.perform_test(block, match_place, &test, make_target_blocks);
+        self.perform_test(span, scrutinee_span, block, match_place, &test, make_target_blocks);
     }
 
     /// Determine the fake borrows that are needed from a set of places that
@@ -1713,6 +1757,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let fake_borrow_temps = self.lower_match_tree(
             block,
             pat.span,
+            pat.span,
             false,
             &mut [&mut guard_candidate, &mut otherwise_candidate],
         );