]> git.lizzy.rs Git - rust.git/commitdiff
Rollup merge of #107819 - clubby789:x-py-root, r=jyn514
authorMichael Goulet <michael@errs.io>
Thu, 9 Feb 2023 04:01:28 +0000 (20:01 -0800)
committerGitHub <noreply@github.com>
Thu, 9 Feb 2023 04:01:28 +0000 (20:01 -0800)
Set `rust-analyzer.check.invocationLocation` to `root`

Add
```json
    "rust-analyzer.check.invocationLocation": "root",
    "rust-analyzer.check.invocationStrategy": "once",
```
to the bundled VS code config. This prevents an error with r-a invoking `python3 x.py` in `src/bootstrap` where `x.py` does not exist.

r? ``@jyn514``

79 files changed:
Cargo.lock
compiler/rustc_ast_pretty/src/pprust/state.rs
compiler/rustc_borrowck/src/diagnostics/mod.rs
compiler/rustc_borrowck/src/type_check/input_output.rs
compiler/rustc_builtin_macros/src/deriving/debug.rs
compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
compiler/rustc_builtin_macros/src/deriving/generic/ty.rs
compiler/rustc_driver_impl/src/lib.rs
compiler/rustc_expand/src/build.rs
compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
compiler/rustc_hir_typeck/src/callee.rs
compiler/rustc_hir_typeck/src/closure.rs
compiler/rustc_hir_typeck/src/expr.rs
compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
compiler/rustc_hir_typeck/src/method/confirm.rs
compiler/rustc_hir_typeck/src/method/mod.rs
compiler/rustc_hir_typeck/src/method/probe.rs
compiler/rustc_infer/src/infer/equate.rs
compiler/rustc_infer/src/infer/higher_ranked/mod.rs
compiler/rustc_infer/src/infer/mod.rs
compiler/rustc_infer/src/infer/sub.rs
compiler/rustc_interface/src/tests.rs
compiler/rustc_lint_defs/src/builtin.rs
compiler/rustc_log/src/lib.rs
compiler/rustc_middle/src/query/mod.rs
compiler/rustc_middle/src/ty/query.rs
compiler/rustc_mir_dataflow/src/drop_flag_effects.rs
compiler/rustc_mir_dataflow/src/move_paths/builder.rs
compiler/rustc_mir_dataflow/src/value_analysis.rs
compiler/rustc_mir_transform/src/elaborate_drops.rs
compiler/rustc_parse/src/parser/ty.rs
compiler/rustc_session/src/options.rs
compiler/rustc_trait_selection/src/solve/fulfill.rs
compiler/rustc_trait_selection/src/solve/infcx_ext.rs
compiler/rustc_trait_selection/src/solve/mod.rs
compiler/rustc_trait_selection/src/solve/project_goals.rs
compiler/rustc_trait_selection/src/solve/search_graph/mod.rs
compiler/rustc_trait_selection/src/solve/trait_goals.rs
compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
compiler/rustc_trait_selection/src/traits/fulfill.rs
compiler/rustc_trait_selection/src/traits/project.rs
compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
compiler/rustc_trait_selection/src/traits/select/confirmation.rs
compiler/rustc_trait_selection/src/traits/select/mod.rs
compiler/rustc_type_ir/src/sty.rs
library/alloc/src/collections/btree/borrow.rs
library/alloc/src/collections/btree/map.rs
library/alloc/src/collections/btree/map/entry.rs
library/alloc/src/collections/btree/map/tests.rs
library/alloc/src/collections/btree/navigate.rs
library/alloc/src/collections/btree/node.rs
library/alloc/src/lib.rs
library/core/src/error.rs
library/core/src/ffi/c_str.rs
library/core/src/slice/memchr.rs
library/std/src/io/error.rs
library/std/src/io/mod.rs
library/std/src/lib.rs
library/std/src/os/fd/owned.rs
library/std/src/os/fd/raw.rs
src/bootstrap/bootstrap.py
src/librustdoc/html/static/images/wheel.svg
src/librustdoc/json/mod.rs
src/tools/miri/tests/pass-dep/shims/pthreads.rs
tests/rustdoc-ui/z-help.stdout
tests/ui/attributes/log-backtrace.rs
tests/ui/derives/deriving-with-repr-packed.rs
tests/ui/derives/deriving-with-repr-packed.stderr
tests/ui/macros/stringify.rs
tests/ui/parser/bad-recover-kw-after-impl.rs [new file with mode: 0644]
tests/ui/parser/bad-recover-ty-after-impl.rs [new file with mode: 0644]
tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs [new file with mode: 0644]
tests/ui/traits/new-solver/provisional-result-done.rs [new file with mode: 0644]
tests/ui/traits/new-solver/provisional-result-done.stderr [new file with mode: 0644]
tests/ui/unpretty/ast-const-trait-bound.rs [new file with mode: 0644]
tests/ui/unpretty/ast-const-trait-bound.stdout [new file with mode: 0644]

index aa2c31ad055dbe328220cea015099ea6ddc14dce..ad01ef5e41f162a918ad976df5ec3beb88a80c13 100644 (file)
@@ -127,6 +127,12 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f8cb5d814eb646a863c4f24978cff2880c4be96ad8cde2c0f0678732902e271"
 
+[[package]]
+name = "arrayvec"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
+
 [[package]]
 name = "arrayvec"
 version = "0.7.0"
@@ -791,7 +797,7 @@ dependencies = [
 name = "clippy_utils"
 version = "0.1.69"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.0",
  "if_chain",
  "itertools",
  "rustc-semver",
@@ -3912,7 +3918,7 @@ dependencies = [
 name = "rustc_data_structures"
 version = "0.0.0"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.0",
  "bitflags",
  "cfg-if",
  "ena",
@@ -4169,7 +4175,7 @@ dependencies = [
 name = "rustc_index"
 version = "0.0.0"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.0",
  "rustc_macros",
  "rustc_serialize",
  "smallvec",
@@ -4866,7 +4872,7 @@ dependencies = [
 name = "rustdoc"
 version = "0.0.0"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.0",
  "askama",
  "expect-test",
  "itertools",
@@ -5375,9 +5381,9 @@ dependencies = [
 
 [[package]]
 name = "strip-ansi-escapes"
-version = "0.1.0"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d63676e2abafa709460982ddc02a3bb586b6d15a49b75c212e06edd3933acee"
+checksum = "011cbb39cf7c1f62871aea3cc46e5817b0937b49e9447370c93cacbe93a766d8"
 dependencies = [
  "vte",
 ]
@@ -6089,9 +6095,9 @@ checksum = "05e42f7c18b8f902290b009cde6d651262f956c98bc51bca4cd1d511c9cd85c7"
 
 [[package]]
 name = "utf8parse"
-version = "0.1.1"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8772a4ccbb4e89959023bc5b7cb8623a795caa7092d99f3aa9501b9484d4557d"
+checksum = "936e4b492acfd135421d8dca4b1aa80a7bfc26e702ef3af710e0752684df5372"
 
 [[package]]
 name = "uuid"
@@ -6122,11 +6128,23 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
 [[package]]
 name = "vte"
-version = "0.3.3"
+version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4f42f536e22f7fcbb407639765c8fd78707a33109301f834a594758bedd6e8cf"
+checksum = "6cbce692ab4ca2f1f3047fcf732430249c0e971bfdd2b234cf2c47ad93af5983"
 dependencies = [
+ "arrayvec 0.5.2",
  "utf8parse",
+ "vte_generate_state_changes",
+]
+
+[[package]]
+name = "vte_generate_state_changes"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d257817081c7dffcdbab24b9e62d2def62e2ff7d00b1c20062551e6cccc145ff"
+dependencies = [
+ "proc-macro2",
+ "quote",
 ]
 
 [[package]]
index d7767efa9841bc65383b76767c821ddae74379d0..cd621bc67a1de9328e4fec0d2ebc27fa721df944 100644 (file)
@@ -1567,8 +1567,18 @@ pub fn print_type_bounds(&mut self, bounds: &[ast::GenericBound]) {
 
             match bound {
                 GenericBound::Trait(tref, modifier) => {
-                    if modifier == &TraitBoundModifier::Maybe {
-                        self.word("?");
+                    match modifier {
+                        TraitBoundModifier::None => {}
+                        TraitBoundModifier::Maybe => {
+                            self.word("?");
+                        }
+                        TraitBoundModifier::MaybeConst => {
+                            self.word_space("~const");
+                        }
+                        TraitBoundModifier::MaybeConstMaybe => {
+                            self.word_space("~const");
+                            self.word("?");
+                        }
                     }
                     self.print_poly_trait_ref(tref);
                 }
index a75ec87be4cac0721b6cdfc58fa3b095c7959048..3006e27e1d5b53882bfaa8528bcee7b4f8ab849b 100644 (file)
@@ -1139,7 +1139,7 @@ fn explain_captures(
                         if let ty::Adt(def, substs) = ty.kind()
                             && Some(def.did()) == tcx.lang_items().pin_type()
                             && let ty::Ref(_, _, hir::Mutability::Mut) = substs.type_at(0).kind()
-                            && let self_ty = infcx.replace_bound_vars_with_fresh_vars(
+                            && let self_ty = infcx.instantiate_binder_with_fresh_vars(
                                 fn_call_span,
                                 LateBoundRegionConversionTime::FnCall,
                                 tcx.fn_sig(method_did).subst(tcx, method_substs).input(0),
index fa9ea769a14f79607e86c7d69dafbec2216b5c1a..c6b78df9a5ff033db5671483da5f41c53ae772c0 100644 (file)
@@ -38,7 +38,7 @@ pub(super) fn check_signature_annotation(&mut self, body: &Body<'tcx>) {
         // so that they represent the view from "inside" the closure.
         let user_provided_sig = self
             .instantiate_canonical_with_fresh_inference_vars(body.span, &user_provided_poly_sig);
-        let user_provided_sig = self.infcx.replace_bound_vars_with_fresh_vars(
+        let user_provided_sig = self.infcx.instantiate_binder_with_fresh_vars(
             body.span,
             LateBoundRegionConversionTime::FnCall,
             user_provided_sig,
index 74e2597830e7ed27a1fd0fae301052628d9ffb9e..e8a353b1c8fcc61474ad64cb001971ede5a5b67a 100644 (file)
@@ -153,7 +153,10 @@ fn expr_for_field(
         let path_debug = cx.path_global(span, cx.std_path(&[sym::fmt, sym::Debug]));
         let ty_dyn_debug = cx.ty(
             span,
-            ast::TyKind::TraitObject(vec![cx.trait_bound(path_debug)], ast::TraitObjectSyntax::Dyn),
+            ast::TyKind::TraitObject(
+                vec![cx.trait_bound(path_debug, false)],
+                ast::TraitObjectSyntax::Dyn,
+            ),
         );
         let ty_slice = cx.ty(
             span,
index 97de40bac34661f12d86e27e12a139ae76ebdd36..970b9115d8d79639aa232db382c0936dbad366e9 100644 (file)
@@ -605,18 +605,26 @@ fn create_derived_impl(
                     let bounds: Vec<_> = self
                         .additional_bounds
                         .iter()
-                        .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                        .map(|p| {
+                            cx.trait_bound(
+                                p.to_path(cx, self.span, type_ident, generics),
+                                self.is_const,
+                            )
+                        })
                         .chain(
                             // Add a bound for the current trait.
                             self.skip_path_as_bound
                                 .not()
-                                .then(|| cx.trait_bound(trait_path.clone())),
+                                .then(|| cx.trait_bound(trait_path.clone(), self.is_const)),
                         )
                         .chain({
                             // Add a `Copy` bound if required.
                             if is_packed && self.needs_copy_as_bound_if_packed {
                                 let p = deriving::path_std!(marker::Copy);
-                                Some(cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                                Some(cx.trait_bound(
+                                    p.to_path(cx, self.span, type_ident, generics),
+                                    self.is_const,
+                                ))
                             } else {
                                 None
                             }
@@ -694,18 +702,24 @@ fn create_derived_impl(
                         let mut bounds: Vec<_> = self
                             .additional_bounds
                             .iter()
-                            .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                            .map(|p| {
+                                cx.trait_bound(
+                                    p.to_path(cx, self.span, type_ident, generics),
+                                    self.is_const,
+                                )
+                            })
                             .collect();
 
                         // Require the current trait.
-                        bounds.push(cx.trait_bound(trait_path.clone()));
+                        bounds.push(cx.trait_bound(trait_path.clone(), self.is_const));
 
                         // Add a `Copy` bound if required.
                         if is_packed && self.needs_copy_as_bound_if_packed {
                             let p = deriving::path_std!(marker::Copy);
-                            bounds.push(
-                                cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)),
-                            );
+                            bounds.push(cx.trait_bound(
+                                p.to_path(cx, self.span, type_ident, generics),
+                                self.is_const,
+                            ));
                         }
 
                         let predicate = ast::WhereBoundPredicate {
@@ -1543,31 +1557,46 @@ fn create_struct_field_access_fields(
                             }),
                         ),
                     );
-                    // In general, fields in packed structs are copied via a
-                    // block, e.g. `&{self.0}`. The one exception is `[u8]`
-                    // fields, which cannot be copied and also never cause
-                    // unaligned references. This exception is allowed to
-                    // handle the `FlexZeroSlice` type in the `zerovec` crate
-                    // within `icu4x-0.9.0`.
-                    //
-                    // Once use of `icu4x-0.9.0` has dropped sufficiently, this
-                    // exception should be removed.
-                    let is_u8_slice = if let TyKind::Slice(ty) = &struct_field.ty.kind &&
-                        let TyKind::Path(None, rustc_ast::Path { segments, .. }) = &ty.kind &&
-                        let [seg] = segments.as_slice() &&
-                        seg.ident.name == sym::u8 && seg.args.is_none()
-                    {
-                        true
-                    } else {
-                        false
-                    };
                     if is_packed {
-                        if is_u8_slice {
+                        // In general, fields in packed structs are copied via a
+                        // block, e.g. `&{self.0}`. The two exceptions are `[u8]`
+                        // and `str` fields, which cannot be copied and also never
+                        // cause unaligned references. These exceptions are allowed
+                        // to handle the `FlexZeroSlice` type in the `zerovec`
+                        // crate within `icu4x-0.9.0`.
+                        //
+                        // Once use of `icu4x-0.9.0` has dropped sufficiently, this
+                        // exception should be removed.
+                        let is_simple_path = |ty: &P<ast::Ty>, sym| {
+                            if let TyKind::Path(None, ast::Path { segments, .. }) = &ty.kind &&
+                                let [seg] = segments.as_slice() &&
+                                seg.ident.name == sym && seg.args.is_none()
+                            {
+                                true
+                            } else {
+                                false
+                            }
+                        };
+
+                        let exception = if let TyKind::Slice(ty) = &struct_field.ty.kind &&
+                            is_simple_path(ty, sym::u8)
+                        {
+                            Some("byte")
+                        } else if is_simple_path(&struct_field.ty, sym::str) {
+                            Some("string")
+                        } else {
+                            None
+                        };
+
+                        if let Some(ty) = exception {
                             cx.sess.parse_sess.buffer_lint_with_diagnostic(
                                 BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
                                 sp,
                                 ast::CRATE_NODE_ID,
-                                "byte slice in a packed struct that derives a built-in trait",
+                                &format!(
+                                    "{} slice in a packed struct that derives a built-in trait",
+                                    ty
+                                ),
                                 rustc_lint_defs::BuiltinLintDiagnostics::ByteSliceInPackedStructWithDerive
                             );
                         } else {
index c6f5f5d080706be7d41c7c52d8840edf6b545b42..aabd5b1f773f70baa3691862eb4a190f8068a8fb 100644 (file)
@@ -154,7 +154,7 @@ fn mk_ty_param(
         .iter()
         .map(|b| {
             let path = b.to_path(cx, span, self_ident, self_generics);
-            cx.trait_bound(path)
+            cx.trait_bound(path, false)
         })
         .collect();
     cx.typaram(span, Ident::new(name, span), bounds, None)
index a392d70f100a4826ddc9e6227c7c20bcabbdbccc..bdf2978cee2587f90fd93661ca1d6151965293cd 100644 (file)
@@ -229,10 +229,6 @@ fn run_compiler(
         registry: diagnostics_registry(),
     };
 
-    if !tracing::dispatcher::has_been_set() {
-        init_rustc_env_logger_with_backtrace_option(&config.opts.unstable_opts.log_backtrace);
-    }
-
     match make_input(config.opts.error_format, &matches.free) {
         Err(reported) => return Err(reported),
         Ok(Some(input)) => {
@@ -1251,16 +1247,7 @@ pub fn install_ice_hook() {
 /// This allows tools to enable rust logging without having to magically match rustc's
 /// tracing crate version.
 pub fn init_rustc_env_logger() {
-    init_rustc_env_logger_with_backtrace_option(&None);
-}
-
-/// This allows tools to enable rust logging without having to magically match rustc's
-/// tracing crate version. In contrast to `init_rustc_env_logger` it allows you to
-/// choose a target module you wish to show backtraces along with its logging.
-pub fn init_rustc_env_logger_with_backtrace_option(backtrace_target: &Option<String>) {
-    if let Err(error) = rustc_log::init_rustc_env_logger_with_backtrace_option(backtrace_target) {
-        early_error(ErrorOutputType::default(), &error.to_string());
-    }
+    init_env_logger("RUSTC_LOG");
 }
 
 /// This allows tools to enable rust logging without having to magically match rustc's
@@ -1324,6 +1311,7 @@ pub(super) fn install() {}
 pub fn main() -> ! {
     let start_time = Instant::now();
     let start_rss = get_resident_set_size();
+    init_rustc_env_logger();
     signal_handler::install();
     let mut callbacks = TimePassesCallbacks::default();
     install_ice_hook();
index 6cd56852f9d686942633ce3b258358c310d56469..b4c12651e7a2d36e7011fac4664f36d63f695c05 100644 (file)
@@ -131,10 +131,14 @@ pub fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef {
         }
     }
 
-    pub fn trait_bound(&self, path: ast::Path) -> ast::GenericBound {
+    pub fn trait_bound(&self, path: ast::Path, is_const: bool) -> ast::GenericBound {
         ast::GenericBound::Trait(
             self.poly_trait_ref(path.span, path),
-            ast::TraitBoundModifier::None,
+            if is_const {
+                ast::TraitBoundModifier::MaybeConst
+            } else {
+                ast::TraitBoundModifier::None
+            },
         )
     }
 
index 21e700418105047a8a52540a41a85c7b26e140b1..236e36f28ca474e5261a54a0b2565149811179d6 100644 (file)
@@ -246,7 +246,7 @@ fn compare_method_predicate_entailment<'tcx>(
 
     let mut wf_tys = FxIndexSet::default();
 
-    let unnormalized_impl_sig = infcx.replace_bound_vars_with_fresh_vars(
+    let unnormalized_impl_sig = infcx.instantiate_binder_with_fresh_vars(
         impl_m_span,
         infer::HigherRankedType,
         tcx.fn_sig(impl_m.def_id).subst_identity(),
@@ -640,7 +640,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     let impl_sig = ocx.normalize(
         &norm_cause,
         param_env,
-        infcx.replace_bound_vars_with_fresh_vars(
+        infcx.instantiate_binder_with_fresh_vars(
             return_span,
             infer::HigherRankedType,
             tcx.fn_sig(impl_m.def_id).subst_identity(),
index c220956a2012e15620f124c86c5942b479587759..089863a66e73be9843af6ea4a5f42098aeb81edf 100644 (file)
@@ -156,7 +156,7 @@ fn try_overloaded_call_step(
                 // fnmut vs fnonce. If so, we have to defer further processing.
                 if self.closure_kind(substs).is_none() {
                     let closure_sig = substs.as_closure().sig();
-                    let closure_sig = self.replace_bound_vars_with_fresh_vars(
+                    let closure_sig = self.instantiate_binder_with_fresh_vars(
                         call_expr.span,
                         infer::FnCall,
                         closure_sig,
@@ -437,7 +437,7 @@ fn confirm_builtin_call(
         // renormalize the associated types at this point, since they
         // previously appeared within a `Binder<>` and hence would not
         // have been normalized before.
-        let fn_sig = self.replace_bound_vars_with_fresh_vars(call_expr.span, infer::FnCall, fn_sig);
+        let fn_sig = self.instantiate_binder_with_fresh_vars(call_expr.span, infer::FnCall, fn_sig);
         let fn_sig = self.normalize(call_expr.span, fn_sig);
 
         // Call the generic checker.
index 90c4e5b6540b0ed511edacc08a34ec8b8628f11b..211fe477a2d8d77bd77890602796e55bfe103a80 100644 (file)
@@ -544,7 +544,7 @@ fn merge_supplied_sig_with_expectation(
             )
             .map(|(hir_ty, &supplied_ty)| {
                 // Instantiate (this part of..) S to S', i.e., with fresh variables.
-                self.replace_bound_vars_with_fresh_vars(
+                self.instantiate_binder_with_fresh_vars(
                     hir_ty.span,
                     LateBoundRegionConversionTime::FnCall,
                     // (*) binder moved to here
@@ -566,7 +566,7 @@ fn merge_supplied_sig_with_expectation(
                 all_obligations.extend(obligations);
             }
 
-            let supplied_output_ty = self.replace_bound_vars_with_fresh_vars(
+            let supplied_output_ty = self.instantiate_binder_with_fresh_vars(
                 decl.output.span(),
                 LateBoundRegionConversionTime::FnCall,
                 supplied_sig.output(),
index 3561992e86ab4ca41a518f241bc3c2ecd1a4a9e4..bb235a4836153aedb9883677474e83942bdda263 100644 (file)
@@ -568,7 +568,7 @@ pub(crate) fn check_expr_path(
                     // placeholder lifetimes with probing, we just replace higher lifetimes
                     // with fresh vars.
                     let span = args.get(i).map(|a| a.span).unwrap_or(expr.span);
-                    let input = self.replace_bound_vars_with_fresh_vars(
+                    let input = self.instantiate_binder_with_fresh_vars(
                         span,
                         infer::LateBoundRegionConversionTime::FnCall,
                         fn_sig.input(i),
@@ -586,7 +586,7 @@ pub(crate) fn check_expr_path(
             // Also, as we just want to check sizedness, instead of introducing
             // placeholder lifetimes with probing, we just replace higher lifetimes
             // with fresh vars.
-            let output = self.replace_bound_vars_with_fresh_vars(
+            let output = self.instantiate_binder_with_fresh_vars(
                 expr.span,
                 infer::LateBoundRegionConversionTime::FnCall,
                 fn_sig.output(),
index 1e14eddd4c86ef511732e116a9dfeafe69b2ba8e..3814ddaf73f44b8e64ebeb89418f1c875dc1da16 100644 (file)
@@ -289,7 +289,7 @@ fn projected_ty_from_poly_trait_ref(
         item_segment: &hir::PathSegment<'_>,
         poly_trait_ref: ty::PolyTraitRef<'tcx>,
     ) -> Ty<'tcx> {
-        let trait_ref = self.replace_bound_vars_with_fresh_vars(
+        let trait_ref = self.instantiate_binder_with_fresh_vars(
             span,
             infer::LateBoundRegionConversionTime::AssocTypeProjection(item_def_id),
             poly_trait_ref,
index 65ca47bfe538bbd5c42cb8854ee9dfa1adcc601b..fa0dc4d84150636f57bcebd7014b102d8bd57596 100644 (file)
@@ -262,7 +262,7 @@ fn fresh_receiver_substs(
                     let original_poly_trait_ref = principal.with_self_ty(this.tcx, object_ty);
                     let upcast_poly_trait_ref = this.upcast(original_poly_trait_ref, trait_def_id);
                     let upcast_trait_ref =
-                        this.replace_bound_vars_with_fresh_vars(upcast_poly_trait_ref);
+                        this.instantiate_binder_with_fresh_vars(upcast_poly_trait_ref);
                     debug!(
                         "original_poly_trait_ref={:?} upcast_trait_ref={:?} target_trait={:?}",
                         original_poly_trait_ref, upcast_trait_ref, trait_def_id
@@ -285,7 +285,7 @@ fn fresh_receiver_substs(
             probe::WhereClausePick(poly_trait_ref) => {
                 // Where clauses can have bound regions in them. We need to instantiate
                 // those to convert from a poly-trait-ref to a trait-ref.
-                self.replace_bound_vars_with_fresh_vars(poly_trait_ref).substs
+                self.instantiate_binder_with_fresh_vars(poly_trait_ref).substs
             }
         }
     }
@@ -506,7 +506,7 @@ fn instantiate_method_sig(
         let sig = self.tcx.fn_sig(def_id).subst(self.tcx, all_substs);
         debug!("type scheme substituted, sig={:?}", sig);
 
-        let sig = self.replace_bound_vars_with_fresh_vars(sig);
+        let sig = self.instantiate_binder_with_fresh_vars(sig);
         debug!("late-bound lifetimes from method instantiated, sig={:?}", sig);
 
         (sig, method_predicates)
@@ -625,10 +625,10 @@ fn upcast(
         upcast_trait_refs.into_iter().next().unwrap()
     }
 
-    fn replace_bound_vars_with_fresh_vars<T>(&self, value: ty::Binder<'tcx, T>) -> T
+    fn instantiate_binder_with_fresh_vars<T>(&self, value: ty::Binder<'tcx, T>) -> T
     where
         T: TypeFoldable<'tcx> + Copy,
     {
-        self.fcx.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, value)
+        self.fcx.instantiate_binder_with_fresh_vars(self.span, infer::FnCall, value)
     }
 }
index 60d4dc326eea16f837983767fc138d6ffda50a5d..d5d10cf272afad674cced63f4473b4c934562a5b 100644 (file)
@@ -401,7 +401,7 @@ fn construct_obligation_for_trait(
         // with bound regions.
         let fn_sig = tcx.fn_sig(def_id).subst(self.tcx, substs);
         let fn_sig =
-            self.replace_bound_vars_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig);
+            self.instantiate_binder_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig);
 
         let InferOk { value, obligations: o } =
             self.at(&obligation.cause, self.param_env).normalize(fn_sig);
index 9ab29a6778fc91eceb2a99bd4ae9f9cbba5683ca..4ce401b52bd269292890b3b9bd3da39132ef1825 100644 (file)
@@ -924,7 +924,7 @@ fn matches_return_type(
             ty::AssocKind::Fn => self.probe(|_| {
                 let substs = self.fresh_substs_for_item(self.span, method.def_id);
                 let fty = self.tcx.fn_sig(method.def_id).subst(self.tcx, substs);
-                let fty = self.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, fty);
+                let fty = self.instantiate_binder_with_fresh_vars(self.span, infer::FnCall, fty);
 
                 if let Some(self_ty) = self_ty {
                     if self
index 46e7813d99e562cd1cff9b39b0224eaa75048fb1..7db4d92a177a1b89b13e9c93f58a3a6f9babe43d 100644 (file)
@@ -129,7 +129,7 @@ fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
                 let a_types = infcx.tcx.anonymize_bound_vars(a_types);
                 let b_types = infcx.tcx.anonymize_bound_vars(b_types);
                 if a_types.bound_vars() == b_types.bound_vars() {
-                    let (a_types, b_types) = infcx.replace_bound_vars_with_placeholders(
+                    let (a_types, b_types) = infcx.instantiate_binder_with_placeholders(
                         a_types.map_bound(|a_types| (a_types, b_types.skip_binder())),
                     );
                     for (a, b) in std::iter::zip(a_types, b_types) {
index 31be107b35472a44dd373d95a7cc17df856b9a94..412e52d8fd7e21bbd2f9143ba587dbabcb7fa7ad 100644 (file)
@@ -38,13 +38,13 @@ pub fn higher_ranked_sub<T>(
         // First, we instantiate each bound region in the supertype with a
         // fresh placeholder region. Note that this automatically creates
         // a new universe if needed.
-        let sup_prime = self.infcx.replace_bound_vars_with_placeholders(sup);
+        let sup_prime = self.infcx.instantiate_binder_with_placeholders(sup);
 
         // Next, we instantiate each bound region in the subtype
         // with a fresh region variable. These region variables --
         // but no other pre-existing region variables -- can name
         // the placeholders.
-        let sub_prime = self.infcx.replace_bound_vars_with_fresh_vars(span, HigherRankedType, sub);
+        let sub_prime = self.infcx.instantiate_binder_with_fresh_vars(span, HigherRankedType, sub);
 
         debug!("a_prime={:?}", sub_prime);
         debug!("b_prime={:?}", sup_prime);
@@ -70,7 +70,7 @@ impl<'tcx> InferCtxt<'tcx> {
     ///
     /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/hrtb.html
     #[instrument(level = "debug", skip(self), ret)]
-    pub fn replace_bound_vars_with_placeholders<T>(&self, binder: ty::Binder<'tcx, T>) -> T
+    pub fn instantiate_binder_with_placeholders<T>(&self, binder: ty::Binder<'tcx, T>) -> T
     where
         T: TypeFoldable<'tcx> + Copy,
     {
index 8e0bcff8d0a89cd794fd77d8902dd7d05fb970b7..35918b8bae1c20b10290401962683d9a88ed13df 100644 (file)
@@ -995,7 +995,7 @@ pub fn subtype_predicate(
 
         Ok(self.commit_if_ok(|_snapshot| {
             let ty::SubtypePredicate { a_is_expected, a, b } =
-                self.replace_bound_vars_with_placeholders(predicate);
+                self.instantiate_binder_with_placeholders(predicate);
 
             let ok = self.at(cause, param_env).sub_exp(a_is_expected, a, b)?;
 
@@ -1008,7 +1008,7 @@ pub fn region_outlives_predicate(
         cause: &traits::ObligationCause<'tcx>,
         predicate: ty::PolyRegionOutlivesPredicate<'tcx>,
     ) {
-        let ty::OutlivesPredicate(r_a, r_b) = self.replace_bound_vars_with_placeholders(predicate);
+        let ty::OutlivesPredicate(r_a, r_b) = self.instantiate_binder_with_placeholders(predicate);
         let origin =
             SubregionOrigin::from_obligation_cause(cause, || RelateRegionParamBound(cause.span));
         self.sub_regions(origin, r_b, r_a); // `b : a` ==> `a <= b`
@@ -1447,7 +1447,14 @@ pub fn fully_resolve<T: TypeFoldable<'tcx>>(&self, value: T) -> FixupResult<'tcx
         value
     }
 
-    pub fn replace_bound_vars_with_fresh_vars<T>(
+    // Instantiates the bound variables in a given binder with fresh inference
+    // variables in the current universe.
+    //
+    // Use this method if you'd like to find some substitution of the binder's
+    // variables (e.g. during a method call). If there isn't a [`LateBoundRegionConversionTime`]
+    // that corresponds to your use case, consider whether or not you should
+    // use [`InferCtxt::instantiate_binder_with_placeholders`] instead.
+    pub fn instantiate_binder_with_fresh_vars<T>(
         &self,
         span: Span,
         lbrct: LateBoundRegionConversionTime,
index 51c34f0d55f6ff715336cc2b45d53c3e2df19a16..532fbd0ffe4c40c685a47ef74098d5945fdacd60 100644 (file)
@@ -161,7 +161,7 @@ fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
                 let a_types = infcx.tcx.anonymize_bound_vars(a_types);
                 let b_types = infcx.tcx.anonymize_bound_vars(b_types);
                 if a_types.bound_vars() == b_types.bound_vars() {
-                    let (a_types, b_types) = infcx.replace_bound_vars_with_placeholders(
+                    let (a_types, b_types) = infcx.instantiate_binder_with_placeholders(
                         a_types.map_bound(|a_types| (a_types, b_types.skip_binder())),
                     );
                     for (a, b) in std::iter::zip(a_types, b_types) {
index 52a4e0e74181f78092fb85230051352b995a23ac..5165ee424e31ba8ad5d9906fa8300ebad0214aa0 100644 (file)
@@ -758,7 +758,6 @@ macro_rules! tracked {
     tracked!(link_only, true);
     tracked!(llvm_plugins, vec![String::from("plugin_name")]);
     tracked!(location_detail, LocationDetail { file: true, line: false, column: false });
-    tracked!(log_backtrace, Some("filter".to_string()));
     tracked!(maximal_hir_to_mir_coverage, true);
     tracked!(merge_functions, Some(MergeFunctions::Disabled));
     tracked!(mir_emit_retag, true);
index 7e9ba4cd22b8d8132f62ad6158678df3b74ad2a8..9d8ad9d9ed9f6f5c7d2fa66b7e0d656ba2393581 100644 (file)
 
 declare_lint! {
     /// The `byte_slice_in_packed_struct_with_derive` lint detects cases where a byte slice field
-    /// (`[u8]`) is used in a `packed` struct that derives one or more built-in traits.
+    /// (`[u8]`) or string slice field (`str`) is used in a `packed` struct that derives one or
+    /// more built-in traits.
     ///
     /// ### Example
     ///
     /// ### Explanation
     ///
     /// This was previously accepted but is being phased out, because fields in packed structs are
-    /// now required to implement `Copy` for `derive` to work. Byte slices are a temporary
-    /// exception because certain crates depended on them.
+    /// now required to implement `Copy` for `derive` to work. Byte slices and string slices are a
+    /// temporary exception because certain crates depended on them.
     pub BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE,
     Warn,
-    "`[u8]` slice used in a packed struct with `derive`",
+    "`[u8]` or `str` used in a packed struct with `derive`",
     @future_incompatible = FutureIncompatibleInfo {
         reference: "issue #107457 <https://github.com/rust-lang/rust/issues/107457>",
         reason: FutureIncompatibilityReason::FutureReleaseErrorReportNow,
index fc1cabd2de95134ab892f7e9f06b8b09d90e2fa2..019fdc30dcec5606fb4d8e0f9a9f045480c19dce 100644 (file)
 use tracing_subscriber::layer::SubscriberExt;
 
 pub fn init_rustc_env_logger() -> Result<(), Error> {
-    init_rustc_env_logger_with_backtrace_option(&None)
-}
-
-pub fn init_rustc_env_logger_with_backtrace_option(
-    backtrace_target: &Option<String>,
-) -> Result<(), Error> {
-    init_env_logger_with_backtrace_option("RUSTC_LOG", backtrace_target)
+    init_env_logger("RUSTC_LOG")
 }
 
 /// In contrast to `init_rustc_env_logger` this allows you to choose an env var
 /// other than `RUSTC_LOG`.
 pub fn init_env_logger(env: &str) -> Result<(), Error> {
-    init_env_logger_with_backtrace_option(env, &None)
-}
-
-pub fn init_env_logger_with_backtrace_option(
-    env: &str,
-    backtrace_target: &Option<String>,
-) -> Result<(), Error> {
     let filter = match env::var(env) {
         Ok(env) => EnvFilter::new(env),
         _ => EnvFilter::default().add_directive(Directive::from(LevelFilter::WARN)),
@@ -106,8 +93,8 @@ pub fn init_env_logger_with_backtrace_option(
     let layer = layer.with_thread_ids(true).with_thread_names(true);
 
     let subscriber = tracing_subscriber::Registry::default().with(filter).with(layer);
-    match backtrace_target {
-        Some(str) => {
+    match env::var(format!("{env}_BACKTRACE")) {
+        Ok(str) => {
             let fmt_layer = tracing_subscriber::fmt::layer()
                 .with_writer(io::stderr)
                 .without_time()
@@ -115,7 +102,7 @@ pub fn init_env_logger_with_backtrace_option(
             let subscriber = subscriber.with(fmt_layer);
             tracing::subscriber::set_global_default(subscriber).unwrap();
         }
-        None => {
+        Err(_) => {
             tracing::subscriber::set_global_default(subscriber).unwrap();
         }
     };
index 7aa9282b9beceb88301dc76df08af1845b4a101b..0a16ede64991de8d36cd4adf23c1ac435a783e07 100644 (file)
     /// This is because the `hir_crate` query gives you access to all other items.
     /// To avoid this fate, do not call `tcx.hir().krate()`; instead,
     /// prefer wrappers like `tcx.visit_all_items_in_krate()`.
-    query hir_crate(key: ()) -> Crate<'tcx> {
+    query hir_crate(key: ()) -> &'tcx Crate<'tcx> {
         arena_cache
         eval_always
         desc { "getting the crate HIR" }
     }
 
     /// All items in the crate.
-    query hir_crate_items(_: ()) -> rustc_middle::hir::ModuleItems {
+    query hir_crate_items(_: ()) -> &'tcx rustc_middle::hir::ModuleItems {
         arena_cache
         eval_always
         desc { "getting HIR crate items" }
@@ -71,7 +71,7 @@
     ///
     /// This can be conveniently accessed by `tcx.hir().visit_item_likes_in_module`.
     /// Avoid calling this query directly.
-    query hir_module_items(key: LocalDefId) -> rustc_middle::hir::ModuleItems {
+    query hir_module_items(key: LocalDefId) -> &'tcx rustc_middle::hir::ModuleItems {
         arena_cache
         desc { |tcx| "getting HIR module items in `{}`", tcx.def_path_str(key.to_def_id()) }
         cache_on_disk_if { true }
         separate_provide_extern
     }
 
-    query unsizing_params_for_adt(key: DefId) -> rustc_index::bit_set::BitSet<u32>
+    query unsizing_params_for_adt(key: DefId) -> &'tcx rustc_index::bit_set::BitSet<u32>
     {
         arena_cache
         desc { |tcx|
 
     /// Maps from the `DefId` of an item (trait/struct/enum/fn) to its
     /// associated generics.
-    query generics_of(key: DefId) -> ty::Generics {
+    query generics_of(key: DefId) -> &'tcx ty::Generics {
         desc { |tcx| "computing generics of `{}`", tcx.def_path_str(key) }
         arena_cache
         cache_on_disk_if { key.is_local() }
     /// These are assembled from the following places:
     /// - `extern` blocks (depending on their `link` attributes)
     /// - the `libs` (`-l`) option
-    query native_libraries(_: CrateNum) -> Vec<NativeLib> {
+    query native_libraries(_: CrateNum) -> &'tcx Vec<NativeLib> {
         arena_cache
         desc { "looking up the native libraries of a linked crate" }
         separate_provide_extern
     }
 
-    query shallow_lint_levels_on(key: hir::OwnerId) -> rustc_middle::lint::ShallowLintLevelMap {
+    query shallow_lint_levels_on(key: hir::OwnerId) -> &'tcx rustc_middle::lint::ShallowLintLevelMap {
         eval_always // fetches `resolutions`
         arena_cache
         desc { |tcx| "looking up lint levels for `{}`", tcx.def_path_str(key.to_def_id()) }
     }
 
-    query lint_expectations(_: ()) -> Vec<(LintExpectationId, LintExpectation)> {
+    query lint_expectations(_: ()) -> &'tcx Vec<(LintExpectationId, LintExpectation)> {
         arena_cache
         desc { "computing `#[expect]`ed lints in this crate" }
     }
     }
 
     /// Set of param indexes for type params that are in the type's representation
-    query params_in_repr(key: DefId) -> rustc_index::bit_set::BitSet<u32> {
+    query params_in_repr(key: DefId) -> &'tcx rustc_index::bit_set::BitSet<u32> {
         desc { "finding type parameters in the representation" }
         arena_cache
         no_hash
     }
 
     /// Create a THIR tree for debugging.
-    query thir_tree(key: ty::WithOptConstParam<LocalDefId>) -> String {
+    query thir_tree(key: ty::WithOptConstParam<LocalDefId>) -> &'tcx String {
         no_hash
         arena_cache
         desc { |tcx| "constructing THIR tree for `{}`", tcx.def_path_str(key.did.to_def_id()) }
     }
 
     /// Create a list-like THIR representation for debugging.
-    query thir_flat(key: ty::WithOptConstParam<LocalDefId>) -> String {
+    query thir_flat(key: ty::WithOptConstParam<LocalDefId>) -> &'tcx String {
         no_hash
         arena_cache
         desc { |tcx| "constructing flat THIR representation for `{}`", tcx.def_path_str(key.did.to_def_id()) }
     /// Set of all the `DefId`s in this crate that have MIR associated with
     /// them. This includes all the body owners, but also things like struct
     /// constructors.
-    query mir_keys(_: ()) -> rustc_data_structures::fx::FxIndexSet<LocalDefId> {
+    query mir_keys(_: ()) -> &'tcx rustc_data_structures::fx::FxIndexSet<LocalDefId> {
         arena_cache
         desc { "getting a list of all mir_keys" }
     }
 
     query symbols_for_closure_captures(
         key: (LocalDefId, LocalDefId)
-    ) -> Vec<rustc_span::Symbol> {
+    ) -> &'tcx Vec<rustc_span::Symbol> {
         arena_cache
         desc {
             |tcx| "finding symbols for captures of closure `{}` in `{}`",
         }
     }
 
-    query mir_generator_witnesses(key: DefId) -> mir::GeneratorLayout<'tcx> {
+    query mir_generator_witnesses(key: DefId) -> &'tcx mir::GeneratorLayout<'tcx> {
         arena_cache
         desc { |tcx| "generator witness types for `{}`", tcx.def_path_str(key) }
         cache_on_disk_if { key.is_local() }
 
     /// Returns coverage summary info for a function, after executing the `InstrumentCoverage`
     /// MIR pass (assuming the -Cinstrument-coverage option is enabled).
-    query coverageinfo(key: ty::InstanceDef<'tcx>) -> mir::CoverageInfo {
+    query coverageinfo(key: ty::InstanceDef<'tcx>) -> &'tcx mir::CoverageInfo {
         desc { |tcx| "retrieving coverage info from MIR for `{}`", tcx.def_path_str(key.def_id()) }
         arena_cache
     }
 
     /// Returns the `CodeRegions` for a function that has instrumented coverage, in case the
     /// function was optimized out before codegen, and before being added to the Coverage Map.
-    query covered_code_regions(key: DefId) -> Vec<&'tcx mir::coverage::CodeRegion> {
+    query covered_code_regions(key: DefId) -> &'tcx Vec<&'tcx mir::coverage::CodeRegion> {
         desc {
             |tcx| "retrieving the covered `CodeRegion`s, if instrumented, for `{}`",
             tcx.def_path_str(key)
         desc { "erasing regions from `{}`", ty }
     }
 
-    query wasm_import_module_map(_: CrateNum) -> FxHashMap<DefId, String> {
+    query wasm_import_module_map(_: CrateNum) -> &'tcx FxHashMap<DefId, String> {
         arena_cache
         desc { "getting wasm import module map" }
     }
         desc { |tcx| "computing the bounds for type parameter `{}`", tcx.hir().ty_param_name(key.1) }
     }
 
-    query trait_def(key: DefId) -> ty::TraitDef {
+    query trait_def(key: DefId) -> &'tcx ty::TraitDef {
         desc { |tcx| "computing trait definition for `{}`", tcx.def_path_str(key) }
         arena_cache
         cache_on_disk_if { key.is_local() }
     }
 
     /// Gets a map with the variance of every item; use `item_variance` instead.
-    query crate_variances(_: ()) -> ty::CrateVariancesMap<'tcx> {
+    query crate_variances(_: ()) -> &'tcx ty::CrateVariancesMap<'tcx> {
         arena_cache
         desc { "computing the variances for items in this crate" }
     }
     }
 
     /// Maps from thee `DefId` of a type to its (inferred) outlives.
-    query inferred_outlives_crate(_: ()) -> ty::CratePredicatesMap<'tcx> {
+    query inferred_outlives_crate(_: ()) -> &'tcx ty::CratePredicatesMap<'tcx> {
         arena_cache
         desc { "computing the inferred outlives predicates for items in this crate" }
     }
     }
 
     /// Maps from a trait item to the trait item "descriptor".
-    query associated_item(key: DefId) -> ty::AssocItem {
+    query associated_item(key: DefId) -> &'tcx ty::AssocItem {
         desc { |tcx| "computing associated item data for `{}`", tcx.def_path_str(key) }
         arena_cache
         cache_on_disk_if { key.is_local() }
     }
 
     /// Collects the associated items defined on a trait or impl.
-    query associated_items(key: DefId) -> ty::AssocItems<'tcx> {
+    query associated_items(key: DefId) -> &'tcx ty::AssocItems<'tcx> {
         arena_cache
         desc { |tcx| "collecting associated items of `{}`", tcx.def_path_str(key) }
     }
     ///
     /// The map returned for `tcx.impl_item_implementor_ids(impl_id)` would be
     ///`{ trait_f: impl_f, trait_g: impl_g }`
-    query impl_item_implementor_ids(impl_id: DefId) -> FxHashMap<DefId, DefId> {
+    query impl_item_implementor_ids(impl_id: DefId) -> &'tcx FxHashMap<DefId, DefId> {
         arena_cache
         desc { |tcx| "comparing impl items against trait for `{}`", tcx.def_path_str(impl_id) }
     }
     ///
     /// The second return value maps from ADTs to ignored derived traits (e.g. Debug and Clone) and
     /// their respective impl (i.e., part of the derive macro)
-    query live_symbols_and_ignored_derived_traits(_: ()) -> (
+    query live_symbols_and_ignored_derived_traits(_: ()) -> &'tcx (
         FxHashSet<LocalDefId>,
         FxHashMap<LocalDefId, Vec<(DefId, DefId)>>
     ) {
 
     /// Gets a complete map from all types to their inherent impls.
     /// Not meant to be used directly outside of coherence.
-    query crate_inherent_impls(k: ()) -> CrateInherentImpls {
+    query crate_inherent_impls(k: ()) -> &'tcx CrateInherentImpls {
         arena_cache
         desc { "finding all inherent impls defined in crate" }
     }
         desc { "checking for private elements in public interfaces" }
     }
 
-    query reachable_set(_: ()) -> FxHashSet<LocalDefId> {
+    query reachable_set(_: ()) -> &'tcx FxHashSet<LocalDefId> {
         arena_cache
         desc { "reachability" }
     }
     }
 
     /// Generates a MIR body for the shim.
-    query mir_shims(key: ty::InstanceDef<'tcx>) -> mir::Body<'tcx> {
+    query mir_shims(key: ty::InstanceDef<'tcx>) -> &'tcx mir::Body<'tcx> {
         arena_cache
         desc { |tcx| "generating MIR shim for `{}`", tcx.def_path_str(key.def_id()) }
     }
         separate_provide_extern
     }
 
-    query codegen_fn_attrs(def_id: DefId) -> CodegenFnAttrs {
+    query codegen_fn_attrs(def_id: DefId) -> &'tcx CodegenFnAttrs {
         desc { |tcx| "computing codegen attributes of `{}`", tcx.def_path_str(def_id) }
         arena_cache
         cache_on_disk_if { def_id.is_local() }
     }
     /// Gets the rendered value of the specified constant or associated constant.
     /// Used by rustdoc.
-    query rendered_const(def_id: DefId) -> String {
+    query rendered_const(def_id: DefId) -> &'tcx String {
         arena_cache
         desc { |tcx| "rendering constant initializer of `{}`", tcx.def_path_str(def_id) }
         cache_on_disk_if { def_id.is_local() }
     }
 
     /// Given a trait `trait_id`, return all known `impl` blocks.
-    query trait_impls_of(trait_id: DefId) -> ty::trait_def::TraitImpls {
+    query trait_impls_of(trait_id: DefId) -> &'tcx ty::trait_def::TraitImpls {
         arena_cache
         desc { |tcx| "finding trait impls of `{}`", tcx.def_path_str(trait_id) }
     }
 
-    query specialization_graph_of(trait_id: DefId) -> specialization_graph::Graph {
+    query specialization_graph_of(trait_id: DefId) -> &'tcx specialization_graph::Graph {
         arena_cache
         desc { |tcx| "building specialization graph of trait `{}`", tcx.def_path_str(trait_id) }
         cache_on_disk_if { true }
         separate_provide_extern
     }
 
-    query dependency_formats(_: ()) -> Lrc<crate::middle::dependency_format::Dependencies> {
+    query dependency_formats(_: ()) -> &'tcx Lrc<crate::middle::dependency_format::Dependencies> {
         arena_cache
         desc { "getting the linkage format of all dependencies" }
     }
     // Does not include external symbols that don't have a corresponding DefId,
     // like the compiler-generated `main` function and so on.
     query reachable_non_generics(_: CrateNum)
-        -> DefIdMap<SymbolExportInfo> {
+        -> &'tcx DefIdMap<SymbolExportInfo> {
         arena_cache
         desc { "looking up the exported symbols of a crate" }
         separate_provide_extern
     /// added or removed in any upstream crate. Instead use the narrower
     /// `upstream_monomorphizations_for`, `upstream_drop_glue_for`, or, even
     /// better, `Instance::upstream_monomorphization()`.
-    query upstream_monomorphizations(_: ()) -> DefIdMap<FxHashMap<SubstsRef<'tcx>, CrateNum>> {
+    query upstream_monomorphizations(_: ()) -> &'tcx DefIdMap<FxHashMap<SubstsRef<'tcx>, CrateNum>> {
         arena_cache
         desc { "collecting available upstream monomorphizations" }
     }
     }
 
     /// Returns a list of all `extern` blocks of a crate.
-    query foreign_modules(_: CrateNum) -> FxHashMap<DefId, ForeignModule> {
+    query foreign_modules(_: CrateNum) -> &'tcx FxHashMap<DefId, ForeignModule> {
         arena_cache
         desc { "looking up the foreign modules of a linked crate" }
         separate_provide_extern
 
     /// Gets the extra data to put in each output filename for a crate.
     /// For example, compiling the `foo` crate with `extra-filename=-a` creates a `libfoo-b.rlib` file.
-    query extra_filename(_: CrateNum) -> String {
+    query extra_filename(_: CrateNum) -> &'tcx String {
         arena_cache
         eval_always
         desc { "looking up the extra filename for a crate" }
     }
 
     /// Gets the paths where the crate came from in the file system.
-    query crate_extern_paths(_: CrateNum) -> Vec<PathBuf> {
+    query crate_extern_paths(_: CrateNum) -> &'tcx Vec<PathBuf> {
         arena_cache
         eval_always
         desc { "looking up the paths for extern crates" }
     /// Does lifetime resolution on items. Importantly, we can't resolve
     /// lifetimes directly on things like trait methods, because of trait params.
     /// See `rustc_resolve::late::lifetimes for details.
-    query resolve_lifetimes(_: hir::OwnerId) -> ResolveLifetimes {
+    query resolve_lifetimes(_: hir::OwnerId) -> &'tcx ResolveLifetimes {
         arena_cache
         desc { "resolving lifetimes" }
     }
         desc { |tcx| "computing crate imported by `{}`", tcx.def_path_str(def_id.to_def_id()) }
     }
 
-    query lib_features(_: ()) -> LibFeatures {
+    query lib_features(_: ()) -> &'tcx LibFeatures {
         arena_cache
         desc { "calculating the lib features map" }
     }
         desc { "calculating the lib features defined in a crate" }
         separate_provide_extern
     }
-    query stability_implications(_: CrateNum) -> FxHashMap<Symbol, Symbol> {
+    query stability_implications(_: CrateNum) -> &'tcx FxHashMap<Symbol, Symbol> {
         arena_cache
         desc { "calculating the implications between `#[unstable]` features defined in a crate" }
         separate_provide_extern
         separate_provide_extern
     }
     /// Returns the lang items defined in another crate by loading it from metadata.
-    query get_lang_items(_: ()) -> LanguageItems {
+    query get_lang_items(_: ()) -> &'tcx LanguageItems {
         arena_cache
         eval_always
         desc { "calculating the lang items map" }
     }
 
     /// Returns all diagnostic items defined in all crates.
-    query all_diagnostic_items(_: ()) -> rustc_hir::diagnostic_items::DiagnosticItems {
+    query all_diagnostic_items(_: ()) -> &'tcx rustc_hir::diagnostic_items::DiagnosticItems {
         arena_cache
         eval_always
         desc { "calculating the diagnostic items map" }
     }
 
     /// Returns the diagnostic items defined in a crate.
-    query diagnostic_items(_: CrateNum) -> rustc_hir::diagnostic_items::DiagnosticItems {
+    query diagnostic_items(_: CrateNum) -> &'tcx rustc_hir::diagnostic_items::DiagnosticItems {
         arena_cache
         desc { "calculating the diagnostic items map in a crate" }
         separate_provide_extern
         desc { "calculating the missing lang items in a crate" }
         separate_provide_extern
     }
-    query visible_parent_map(_: ()) -> DefIdMap<DefId> {
+    query visible_parent_map(_: ()) -> &'tcx DefIdMap<DefId> {
         arena_cache
         desc { "calculating the visible parent map" }
     }
-    query trimmed_def_paths(_: ()) -> FxHashMap<DefId, Symbol> {
+    query trimmed_def_paths(_: ()) -> &'tcx FxHashMap<DefId, Symbol> {
         arena_cache
         desc { "calculating trimmed def paths" }
     }
         desc { "seeing if we're missing an `extern crate` item for this crate" }
         separate_provide_extern
     }
-    query used_crate_source(_: CrateNum) -> Lrc<CrateSource> {
+    query used_crate_source(_: CrateNum) -> &'tcx Lrc<CrateSource> {
         arena_cache
         eval_always
         desc { "looking at the source for a crate" }
         separate_provide_extern
     }
     /// Returns the debugger visualizers defined for this crate.
-    query debugger_visualizers(_: CrateNum) -> Vec<rustc_span::DebuggerVisualizerFile> {
+    query debugger_visualizers(_: CrateNum) -> &'tcx Vec<rustc_span::DebuggerVisualizerFile> {
         arena_cache
         desc { "looking up the debugger visualizers for this crate" }
         separate_provide_extern
         desc { |tcx| "finding names imported by glob use for `{}`", tcx.def_path_str(def_id.to_def_id()) }
     }
 
-    query stability_index(_: ()) -> stability::Index {
+    query stability_index(_: ()) -> &'tcx stability::Index {
         arena_cache
         eval_always
         desc { "calculating the stability index for the local crate" }
     ///
     /// This query returns an `&Arc` because codegen backends need the value even after the `TyCtxt`
     /// has been destroyed.
-    query output_filenames(_: ()) -> Arc<OutputFilenames> {
+    query output_filenames(_: ()) -> &'tcx Arc<OutputFilenames> {
         feedable
         desc { "getting output filenames" }
         arena_cache
         remap_env_constness
     }
 
-    query supported_target_features(_: CrateNum) -> FxHashMap<String, Option<Symbol>> {
+    query supported_target_features(_: CrateNum) -> &'tcx FxHashMap<String, Option<Symbol>> {
         arena_cache
         eval_always
         desc { "looking up supported target features" }
     /// span) for an *existing* error. Therefore, it is best-effort, and may never handle
     /// all of the cases that the normal `ty::Ty`-based wfcheck does. This is fine,
     /// because the `ty::Ty`-based wfcheck is always run.
-    query diagnostic_hir_wf_check(key: (ty::Predicate<'tcx>, traits::WellFormedLoc)) -> Option<traits::ObligationCause<'tcx>> {
+    query diagnostic_hir_wf_check(
+        key: (ty::Predicate<'tcx>, traits::WellFormedLoc)
+    ) -> &'tcx Option<traits::ObligationCause<'tcx>> {
         arena_cache
         eval_always
         no_hash
         desc { "performing HIR wf-checking for predicate `{:?}` at item `{:?}`", key.0, key.1 }
     }
 
-
     /// The list of backend features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
     /// `--target` and similar).
-    query global_backend_features(_: ()) -> Vec<String> {
+    query global_backend_features(_: ()) -> &'tcx Vec<String> {
         arena_cache
         eval_always
         desc { "computing the backend features for CLI flags" }
     }
 
-    query generator_diagnostic_data(key: DefId) -> Option<GeneratorDiagnosticData<'tcx>> {
+    query generator_diagnostic_data(key: DefId) -> &'tcx Option<GeneratorDiagnosticData<'tcx>> {
         arena_cache
         desc { |tcx| "looking up generator diagnostic data of `{}`", tcx.def_path_str(key) }
         separate_provide_extern
index 7151b79c5ab63f4b4b7ba8a56a4e5cd275320889..933aaadd62e1dd4a34dfc36410a192d904b2f259 100644 (file)
@@ -112,15 +112,15 @@ macro_rules! query_helper_param_ty {
     ($K:ty) => { $K };
 }
 
-macro_rules! query_storage {
-    ([][$K:ty, $V:ty]) => {
-        <<$K as Key>::CacheSelector as CacheSelector<'tcx, $V>>::Cache
+macro_rules! query_if_arena {
+    ([] $arena:ty, $no_arena:ty) => {
+        $no_arena
     };
-    ([(arena_cache) $($rest:tt)*][$K:ty, $V:ty]) => {
-        <<$K as Key>::CacheSelector as CacheSelector<'tcx, $V>>::ArenaCache
+    ([(arena_cache) $($rest:tt)*] $arena:ty, $no_arena:ty) => {
+        $arena
     };
-    ([$other:tt $($modifiers:tt)*][$($args:tt)*]) => {
-        query_storage!([$($modifiers)*][$($args)*])
+    ([$other:tt $($modifiers:tt)*]$($args:tt)*) => {
+        query_if_arena!([$($modifiers)*]$($args)*)
     };
 }
 
@@ -184,23 +184,30 @@ pub mod query_keys {
 
             $(pub type $name<'tcx> = $($K)*;)*
         }
-        #[allow(nonstandard_style, unused_lifetimes)]
+        #[allow(nonstandard_style, unused_lifetimes, unused_parens)]
         pub mod query_values {
             use super::*;
 
-            $(pub type $name<'tcx> = $V;)*
+            $(pub type $name<'tcx> = query_if_arena!([$($modifiers)*] <$V as Deref>::Target, $V);)*
         }
-        #[allow(nonstandard_style, unused_lifetimes)]
+        #[allow(nonstandard_style, unused_lifetimes, unused_parens)]
         pub mod query_storage {
             use super::*;
 
-            $(pub type $name<'tcx> = query_storage!([$($modifiers)*][$($K)*, $V]);)*
+            $(
+                pub type $name<'tcx> = query_if_arena!([$($modifiers)*]
+                    <<$($K)* as Key>::CacheSelector
+                        as CacheSelector<'tcx, <$V as Deref>::Target>>::ArenaCache,
+                    <<$($K)* as Key>::CacheSelector as CacheSelector<'tcx, $V>>::Cache
+                );
+            )*
         }
+
         #[allow(nonstandard_style, unused_lifetimes)]
         pub mod query_stored {
             use super::*;
 
-            $(pub type $name<'tcx> = <query_storage::$name<'tcx> as QueryStorage>::Stored;)*
+            $(pub type $name<'tcx> = $V;)*
         }
 
         #[derive(Default)]
@@ -226,7 +233,7 @@ impl<'tcx> TyCtxt<'tcx> {
             $($(#[$attr])*
             #[inline(always)]
             #[must_use]
-            pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> query_stored::$name<'tcx>
+            pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> $V
             {
                 self.at(DUMMY_SP).$name(key)
             })*
@@ -235,7 +242,7 @@ pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> query_stored::$name<'
         impl<'tcx> TyCtxtAt<'tcx> {
             $($(#[$attr])*
             #[inline(always)]
-            pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> query_stored::$name<'tcx>
+            pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> $V
             {
                 let key = key.into_query_param();
                 opt_remap_env_constness!([$($modifiers)*][key]);
@@ -306,7 +313,7 @@ fn $name(
                 span: Span,
                 key: query_keys::$name<'tcx>,
                 mode: QueryMode,
-            ) -> Option<query_stored::$name<'tcx>>;)*
+            ) -> Option<$V>;)*
         }
     };
 }
@@ -328,7 +335,7 @@ macro_rules! define_feedable {
         $(impl<'tcx, K: IntoQueryParam<$($K)*> + Copy> TyCtxtFeed<'tcx, K> {
             $(#[$attr])*
             #[inline(always)]
-            pub fn $name(self, value: $V) -> query_stored::$name<'tcx> {
+            pub fn $name(self, value: query_values::$name<'tcx>) -> $V {
                 let key = self.key().into_query_param();
                 opt_remap_env_constness!([$($modifiers)*][key]);
 
index 3224e13f7af4bfe9da8c9fd3b045edadee2b5496..0d466bbe56e01d82b7d5550ca8dc2688495c3a0c 100644 (file)
@@ -1,5 +1,5 @@
 use crate::elaborate_drops::DropFlagState;
-use rustc_middle::mir::{self, Body, Location};
+use rustc_middle::mir::{self, Body, Location, Terminator, TerminatorKind};
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_target::abi::VariantIdx;
 
@@ -194,6 +194,17 @@ pub fn drop_flag_effects_for_location<'tcx, F>(
         on_all_children_bits(tcx, body, move_data, path, |mpi| callback(mpi, DropFlagState::Absent))
     }
 
+    // Drop does not count as a move but we should still consider the variable uninitialized.
+    if let Some(Terminator { kind: TerminatorKind::Drop { place, .. }, .. }) =
+        body.stmt_at(loc).right()
+    {
+        if let LookupResult::Exact(mpi) = move_data.rev_lookup.find(place.as_ref()) {
+            on_all_children_bits(tcx, body, move_data, mpi, |mpi| {
+                callback(mpi, DropFlagState::Absent)
+            })
+        }
+    }
+
     debug!("drop_flag_effects: assignment for location({:?})", loc);
 
     for_location_inits(tcx, body, move_data, loc, |mpi| callback(mpi, DropFlagState::Present));
index 0195693a7cb0e6d9bf8639e83d8e96a5b59797a3..115c8afcce0cf7c15964bd53b175366c0ac6b7fd 100644 (file)
@@ -376,7 +376,8 @@ fn gather_terminator(&mut self, term: &Terminator<'tcx>) {
             | TerminatorKind::Resume
             | TerminatorKind::Abort
             | TerminatorKind::GeneratorDrop
-            | TerminatorKind::Unreachable => {}
+            | TerminatorKind::Unreachable
+            | TerminatorKind::Drop { .. } => {}
 
             TerminatorKind::Assert { ref cond, .. } => {
                 self.gather_operand(cond);
@@ -391,10 +392,6 @@ fn gather_terminator(&mut self, term: &Terminator<'tcx>) {
                 self.create_move_path(place);
                 self.gather_init(place.as_ref(), InitKind::Deep);
             }
-
-            TerminatorKind::Drop { place, target: _, unwind: _ } => {
-                self.gather_move(place);
-            }
             TerminatorKind::DropAndReplace { place, ref value, .. } => {
                 self.create_move_path(place);
                 self.gather_operand(value);
index 8bf6493be4b0168ba6e78d8be9d0cbb7c038382c..a6ef2a742c8736219f84946e85a8e6e44ee2c544 100644 (file)
@@ -223,13 +223,13 @@ fn handle_terminator(&self, terminator: &Terminator<'tcx>, state: &mut State<Sel
         self.super_terminator(terminator, state)
     }
 
-    fn super_terminator(&self, terminator: &Terminator<'tcx>, _state: &mut State<Self::Value>) {
+    fn super_terminator(&self, terminator: &Terminator<'tcx>, state: &mut State<Self::Value>) {
         match &terminator.kind {
             TerminatorKind::Call { .. } | TerminatorKind::InlineAsm { .. } => {
                 // Effect is applied by `handle_call_return`.
             }
-            TerminatorKind::Drop { .. } => {
-                // We don't track dropped places.
+            TerminatorKind::Drop { place, .. } => {
+                state.flood_with(place.as_ref(), self.map(), Self::Value::bottom());
             }
             TerminatorKind::DropAndReplace { .. } | TerminatorKind::Yield { .. } => {
                 // They would have an effect, but are not allowed in this phase.
index 65f4956d23acd5e7722e75caf517269a838b21d7..c2ff8645635e01597ea6c0d55ece679df9e80f9f 100644 (file)
 use rustc_target::abi::VariantIdx;
 use std::fmt;
 
+/// During MIR building, Drop and DropAndReplace terminators are inserted in every place where a drop may occur.
+/// However, in this phase, the presence of these terminators does not guarantee that a destructor will run,
+/// as the target of the drop may be uninitialized.
+/// In general, the compiler cannot determine at compile time whether a destructor will run or not.
+///
+/// At a high level, this pass refines Drop and DropAndReplace to only run the destructor if the
+/// target is initialized. The way this is achievied is by inserting drop flags for every variable
+/// that may be dropped, and then using those flags to determine whether a destructor should run.
+/// This pass also removes DropAndReplace, replacing it with a Drop paired with an assign statement.
+/// Once this is complete, Drop terminators in the MIR correspond to a call to the "drop glue" or
+/// "drop shim" for the type of the dropped place.
+///
+/// This pass relies on dropped places having an associated move path, which is then used to determine
+/// the initialization status of the place and its descendants.
+/// It's worth noting that a MIR containing a Drop without an associated move path is probably ill formed,
+/// as it would allow running a destructor on a place behind a reference:
+///
+/// ```text
+// fn drop_term<T>(t: &mut T) {
+//     mir!(
+//         {
+//             Drop(*t, exit)
+//         }
+//         exit = {
+//             Return()
+//         }
+//     )
+// }
+/// ```
 pub struct ElaborateDrops;
 
 impl<'tcx> MirPass<'tcx> for ElaborateDrops {
index a19ea04fa5e75e47128fa769952be3b6083a68c6..5b92563fc358b68b1bbf824feacef2d9542e4a09 100644 (file)
@@ -694,8 +694,9 @@ fn parse_generic_bounds_common(
         // `where`, so stop if it's it.
         // We also continue if we find types (not traits), again for error recovery.
         while self.can_begin_bound()
-            || self.token.can_begin_type()
-            || (self.token.is_reserved_ident() && !self.token.is_keyword(kw::Where))
+            || (self.may_recover()
+                && (self.token.can_begin_type()
+                    || (self.token.is_reserved_ident() && !self.token.is_keyword(kw::Where))))
         {
             if self.token.is_keyword(kw::Dyn) {
                 // Account for `&dyn Trait + dyn Other`.
index 0db4d85ff4b679f4934bfe5a0ee7edef577454fe..61cb81aec3de07d583251348574cbc3cfeac54ec 100644 (file)
@@ -1413,8 +1413,6 @@ pub(crate) fn parse_proc_macro_execution_strategy(
         "what location details should be tracked when using caller_location, either \
         `none`, or a comma separated list of location details, for which \
         valid options are `file`, `line`, and `column` (default: `file,line,column`)"),
-    log_backtrace: Option<String> = (None, parse_opt_string, [TRACKED],
-        "add a backtrace along with logging"),
     ls: bool = (false, parse_bool, [UNTRACKED],
         "list the symbols defined by a library crate (default: no)"),
     macro_backtrace: bool = (false, parse_bool, [UNTRACKED],
index a2c15123b4fbd7cbb7e818c0bf6859f76ee845cb..c1936b7dbe41ec0743130a33af65837e39b92345 100644 (file)
@@ -74,7 +74,7 @@ fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentE
                                     )
                                 }
                                 ty::PredicateKind::Subtype(pred) => {
-                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                    let (a, b) = infcx.instantiate_binder_with_placeholders(
                                         goal.predicate.kind().rebind((pred.a, pred.b)),
                                     );
                                     let expected_found = ExpectedFound::new(true, a, b);
@@ -84,7 +84,7 @@ fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentE
                                     )
                                 }
                                 ty::PredicateKind::Coerce(pred) => {
-                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                    let (a, b) = infcx.instantiate_binder_with_placeholders(
                                         goal.predicate.kind().rebind((pred.a, pred.b)),
                                     );
                                     let expected_found = ExpectedFound::new(false, a, b);
@@ -94,7 +94,7 @@ fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentE
                                     )
                                 }
                                 ty::PredicateKind::ConstEquate(a, b) => {
-                                    let (a, b) = infcx.replace_bound_vars_with_placeholders(
+                                    let (a, b) = infcx.instantiate_binder_with_placeholders(
                                         goal.predicate.kind().rebind((a, b)),
                                     );
                                     let expected_found = ExpectedFound::new(true, a, b);
index 42f597c781d257e0f97506d931d5121b5d5a83fd..36f987c9f9cb6d3e1a2db0bbcd2e588e9c40c373 100644 (file)
@@ -26,7 +26,7 @@ fn eq<T: ToTrace<'tcx>>(
         rhs: T,
     ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution>;
 
-    fn instantiate_bound_vars_with_infer<T: TypeFoldable<'tcx> + Copy>(
+    fn instantiate_binder_with_infer<T: TypeFoldable<'tcx> + Copy>(
         &self,
         value: ty::Binder<'tcx, T>,
     ) -> T;
@@ -65,11 +65,11 @@ fn eq<T: ToTrace<'tcx>>(
             })
     }
 
-    fn instantiate_bound_vars_with_infer<T: TypeFoldable<'tcx> + Copy>(
+    fn instantiate_binder_with_infer<T: TypeFoldable<'tcx> + Copy>(
         &self,
         value: ty::Binder<'tcx, T>,
     ) -> T {
-        self.replace_bound_vars_with_fresh_vars(
+        self.instantiate_binder_with_fresh_vars(
             DUMMY_SP,
             LateBoundRegionConversionTime::HigherRankedType,
             value,
index e4725c0a1b7326895344eeb0a31dcefe967ca4e7..9f092b6018f483303bc1691784701619f33fff14 100644 (file)
@@ -304,7 +304,7 @@ fn compute_goal(&mut self, goal: Goal<'tcx, ty::Predicate<'tcx>>) -> QueryResult
                 }
             }
         } else {
-            let kind = self.infcx.replace_bound_vars_with_placeholders(kind);
+            let kind = self.infcx.instantiate_binder_with_placeholders(kind);
             let goal = goal.with(self.tcx(), ty::Binder::dummy(kind));
             let (_, certainty) = self.evaluate_goal(goal)?;
             self.make_canonical_response(certainty)
index f9acf7a53eee5b25b95bd098d87a0a45f057ba0c..e3ec71d1b4f7375643eef5d6393af37c1b140675 100644 (file)
@@ -323,7 +323,7 @@ fn consider_assumption(
         {
             ecx.infcx.probe(|_| {
                 let assumption_projection_pred =
-                    ecx.infcx.instantiate_bound_vars_with_infer(poly_projection_pred);
+                    ecx.infcx.instantiate_binder_with_infer(poly_projection_pred);
                 let nested_goals = ecx.infcx.eq(
                     goal.param_env,
                     goal.predicate.projection_ty,
index 7514c7ee55170482df63a66136f376b39492629f..a2ca4bc189c87faae28f66fa694633ab1ade0125 100644 (file)
@@ -7,7 +7,7 @@
 use overflow::OverflowData;
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::TyCtxt;
-use std::collections::hash_map::Entry;
+use std::{collections::hash_map::Entry, mem};
 
 rustc_index::newtype_index! {
     pub struct StackDepth {}
@@ -134,12 +134,15 @@ pub(super) fn try_finalize_goal(
         let provisional_entry_index = *cache.lookup_table.get(&goal).unwrap();
         let provisional_entry = &mut cache.entries[provisional_entry_index];
         let depth = provisional_entry.depth;
+        // We eagerly update the response in the cache here. If we have to reevaluate
+        // this goal we use the new response when hitting a cycle, and we definitely
+        // want to access the final response whenever we look at the cache.
+        let prev_response = mem::replace(&mut provisional_entry.response, response);
+
         // Was the current goal the root of a cycle and was the provisional response
         // different from the final one.
-        if has_been_used && provisional_entry.response != response {
-            // If so, update the provisional reponse for this goal...
-            provisional_entry.response = response;
-            // ...remove all entries whose result depends on this goal
+        if has_been_used && prev_response != response {
+            // If so, remove all entries whose result depends on this goal
             // from the provisional cache...
             //
             // That's not completely correct, as a nested goal can also
index 1cf1efc97049bcb740fa65217a2a18b5983d77fb..06a72e95d4905461814477d70ad25e42d060f91b 100644 (file)
@@ -72,7 +72,7 @@ fn consider_assumption(
             // FIXME: Constness and polarity
             ecx.infcx.probe(|_| {
                 let assumption_trait_pred =
-                    ecx.infcx.instantiate_bound_vars_with_infer(poly_trait_pred);
+                    ecx.infcx.instantiate_binder_with_infer(poly_trait_pred);
                 let nested_goals = ecx.infcx.eq(
                     goal.param_env,
                     goal.predicate.trait_ref,
index 5007a019e1892a3995400c1a7fa8e2550743b284..1ee35a86e626424a3c6a0871f9b84f3f01145423 100644 (file)
@@ -54,7 +54,7 @@ pub(super) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
         }
 
         ty::GeneratorWitness(types) => {
-            Ok(infcx.replace_bound_vars_with_placeholders(types).to_vec())
+            Ok(infcx.instantiate_binder_with_placeholders(types).to_vec())
         }
 
         ty::GeneratorWitnessMIR(..) => todo!(),
@@ -174,7 +174,7 @@ pub(super) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
         }
 
         ty::GeneratorWitness(types) => {
-            Ok(infcx.replace_bound_vars_with_placeholders(types).to_vec())
+            Ok(infcx.instantiate_binder_with_placeholders(types).to_vec())
         }
 
         ty::GeneratorWitnessMIR(..) => todo!(),
index 6bf453c3ff084376b2afa27c74384acbf4e5a8bd..84045c4d0edea11f5e61f766a0f1bc3cf1f607e8 100644 (file)
@@ -22,7 +22,7 @@ pub fn recompute_applicable_impls<'tcx>(
     let impl_may_apply = |impl_def_id| {
         let ocx = ObligationCtxt::new_in_snapshot(infcx);
         let placeholder_obligation =
-            infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+            infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let obligation_trait_ref =
             ocx.normalize(&ObligationCause::dummy(), param_env, placeholder_obligation.trait_ref);
 
@@ -47,11 +47,11 @@ pub fn recompute_applicable_impls<'tcx>(
     let param_env_candidate_may_apply = |poly_trait_predicate: ty::PolyTraitPredicate<'tcx>| {
         let ocx = ObligationCtxt::new_in_snapshot(infcx);
         let placeholder_obligation =
-            infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+            infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let obligation_trait_ref =
             ocx.normalize(&ObligationCause::dummy(), param_env, placeholder_obligation.trait_ref);
 
-        let param_env_predicate = infcx.replace_bound_vars_with_fresh_vars(
+        let param_env_predicate = infcx.instantiate_binder_with_fresh_vars(
             DUMMY_SP,
             LateBoundRegionConversionTime::HigherRankedType,
             poly_trait_predicate,
index f6d0b9713f0d0ca1d03da77d4e798516beee410e..cf1e05ada4713615087d28181215dd5dd9d95660 100644 (file)
@@ -1716,7 +1716,7 @@ fn report_projection_error(
             let (values, err) = if let ty::PredicateKind::Clause(ty::Clause::Projection(data)) =
                 bound_predicate.skip_binder()
             {
-                let data = self.replace_bound_vars_with_fresh_vars(
+                let data = self.instantiate_binder_with_fresh_vars(
                     obligation.cause.span,
                     infer::LateBoundRegionConversionTime::HigherRankedType,
                     bound_predicate.rebind(data),
index 91da690a00056d58fc9fcfec0746d832c01de720..59aef52910ee3f287b359383db57b2fcb1e31d61 100644 (file)
@@ -898,7 +898,7 @@ fn suggest_fn_call(
             return false;
         }
 
-        let self_ty = self.replace_bound_vars_with_fresh_vars(
+        let self_ty = self.instantiate_binder_with_fresh_vars(
             DUMMY_SP,
             LateBoundRegionConversionTime::FnCall,
             trait_pred.self_ty(),
@@ -1191,7 +1191,7 @@ fn extract_callable_info(
             }
         }) else { return None; };
 
-        let output = self.replace_bound_vars_with_fresh_vars(
+        let output = self.instantiate_binder_with_fresh_vars(
             DUMMY_SP,
             LateBoundRegionConversionTime::FnCall,
             output,
@@ -1200,7 +1200,7 @@ fn extract_callable_info(
             .skip_binder()
             .iter()
             .map(|ty| {
-                self.replace_bound_vars_with_fresh_vars(
+                self.instantiate_binder_with_fresh_vars(
                     DUMMY_SP,
                     LateBoundRegionConversionTime::FnCall,
                     inputs.rebind(*ty),
@@ -3806,13 +3806,13 @@ fn hint_missing_borrow<'tcx>(
     err: &mut Diagnostic,
 ) {
     let found_args = match found.kind() {
-        ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
+        ty::FnPtr(f) => infcx.instantiate_binder_with_placeholders(*f).inputs().iter(),
         kind => {
             span_bug!(span, "found was converted to a FnPtr above but is now {:?}", kind)
         }
     };
     let expected_args = match expected.kind() {
-        ty::FnPtr(f) => infcx.replace_bound_vars_with_placeholders(*f).inputs().iter(),
+        ty::FnPtr(f) => infcx.instantiate_binder_with_placeholders(*f).inputs().iter(),
         kind => {
             span_bug!(span, "expected was converted to a FnPtr above but is now {:?}", kind)
         }
index 18d30771035fdbcebf4bdf961ff9bbccd2993ed1..3adc1e62e0d4853368bb663dba6e88d5f978431d 100644 (file)
@@ -321,7 +321,7 @@ fn process_obligation(
                 | ty::PredicateKind::ConstEvaluatable(..)
                 | ty::PredicateKind::ConstEquate(..) => {
                     let pred =
-                        ty::Binder::dummy(infcx.replace_bound_vars_with_placeholders(binder));
+                        ty::Binder::dummy(infcx.instantiate_binder_with_placeholders(binder));
                     ProcessResult::Changed(mk_pending(vec![obligation.with(infcx.tcx, pred)]))
                 }
                 ty::PredicateKind::Ambiguous => ProcessResult::Unchanged,
index 53cae3e720c5ae6e2ac1fd70a634c53202223d03..aa81bc640aa6c56367e4e9cdf87abf9e7e73984e 100644 (file)
@@ -215,7 +215,7 @@ pub(super) fn poly_project_and_unify_type<'cx, 'tcx>(
     let r = infcx.commit_if_ok(|_snapshot| {
         let old_universe = infcx.universe();
         let placeholder_predicate =
-            infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+            infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let new_universe = infcx.universe();
 
         let placeholder_obligation = obligation.with(infcx.tcx, placeholder_predicate);
@@ -2046,7 +2046,7 @@ fn confirm_param_env_candidate<'cx, 'tcx>(
     let cause = &obligation.cause;
     let param_env = obligation.param_env;
 
-    let cache_entry = infcx.replace_bound_vars_with_fresh_vars(
+    let cache_entry = infcx.instantiate_binder_with_fresh_vars(
         cause.span,
         LateBoundRegionConversionTime::HigherRankedType,
         poly_cache_entry,
index bba07ed965b210693badf57439a285fd71022fef..e9f7c3bc4cca2ecb93a54bb13e454f2e46d12818 100644 (file)
@@ -488,7 +488,7 @@ fn assemble_candidates_from_object_ty(
 
             let poly_trait_predicate = self.infcx.resolve_vars_if_possible(obligation.predicate);
             let placeholder_trait_predicate =
-                self.infcx.replace_bound_vars_with_placeholders(poly_trait_predicate);
+                self.infcx.instantiate_binder_with_placeholders(poly_trait_predicate);
 
             // Count only those upcast versions that match the trait-ref
             // we are looking for. Specifically, do not only check for the
index 94d9eb8f587a70ebbd9383cccdab5c516cdbca04..fcc4820c2a6b6ff424131ceaac1a69ec4b5399a8 100644 (file)
@@ -151,7 +151,7 @@ fn confirm_projection_candidate(
 
         let trait_predicate = self.infcx.shallow_resolve(obligation.predicate);
         let placeholder_trait_predicate =
-            self.infcx.replace_bound_vars_with_placeholders(trait_predicate).trait_ref;
+            self.infcx.instantiate_binder_with_placeholders(trait_predicate).trait_ref;
         let placeholder_self_ty = placeholder_trait_predicate.self_ty();
         let placeholder_trait_predicate = ty::Binder::dummy(placeholder_trait_predicate);
         let (def_id, substs) = match *placeholder_self_ty.kind() {
@@ -336,7 +336,7 @@ fn vtable_auto_impl(
             let cause = obligation.derived_cause(BuiltinDerivedObligation);
 
             let poly_trait_ref = obligation.predicate.to_poly_trait_ref();
-            let trait_ref = self.infcx.replace_bound_vars_with_placeholders(poly_trait_ref);
+            let trait_ref = self.infcx.instantiate_binder_with_placeholders(poly_trait_ref);
             let trait_obligations: Vec<PredicateObligation<'_>> = self.impl_or_trait_obligations(
                 &cause,
                 obligation.recursion_depth + 1,
@@ -427,7 +427,7 @@ fn confirm_object_candidate(
         let tcx = self.tcx();
         debug!(?obligation, ?index, "confirm_object_candidate");
 
-        let trait_predicate = self.infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+        let trait_predicate = self.infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let self_ty = self.infcx.shallow_resolve(trait_predicate.self_ty());
         let obligation_trait_ref = ty::Binder::dummy(trait_predicate.trait_ref);
         let ty::Dynamic(data, ..) = *self_ty.kind() else {
@@ -437,7 +437,7 @@ fn confirm_object_candidate(
         let object_trait_ref = data.principal().unwrap_or_else(|| {
             span_bug!(obligation.cause.span, "object candidate with no principal")
         });
-        let object_trait_ref = self.infcx.replace_bound_vars_with_fresh_vars(
+        let object_trait_ref = self.infcx.instantiate_binder_with_fresh_vars(
             obligation.cause.span,
             HigherRankedType,
             object_trait_ref,
@@ -629,7 +629,7 @@ fn confirm_fn_pointer_candidate(
         }
 
         // Confirm the `type Output: Sized;` bound that is present on `FnOnce`
-        let output_ty = self.infcx.replace_bound_vars_with_placeholders(sig.output());
+        let output_ty = self.infcx.instantiate_binder_with_placeholders(sig.output());
         let output_ty = normalize_with_depth_to(
             self,
             obligation.param_env,
@@ -652,7 +652,7 @@ fn confirm_trait_alias_candidate(
         debug!(?obligation, "confirm_trait_alias_candidate");
 
         let alias_def_id = obligation.predicate.def_id();
-        let predicate = self.infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+        let predicate = self.infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let trait_ref = predicate.trait_ref;
         let trait_def_id = trait_ref.def_id;
         let substs = trait_ref.substs;
index 0c6b2406bbdafb0cd0e547a405e72cc988e9a494..984d6fde2686c58384a99a272062b95191794f84 100644 (file)
@@ -1618,7 +1618,7 @@ fn match_projection_obligation_against_definition_bounds(
     ) -> smallvec::SmallVec<[(usize, ty::BoundConstness); 2]> {
         let poly_trait_predicate = self.infcx.resolve_vars_if_possible(obligation.predicate);
         let placeholder_trait_predicate =
-            self.infcx.replace_bound_vars_with_placeholders(poly_trait_predicate);
+            self.infcx.instantiate_binder_with_placeholders(poly_trait_predicate);
         debug!(?placeholder_trait_predicate);
 
         let tcx = self.infcx.tcx;
@@ -1738,7 +1738,7 @@ pub(super) fn match_projection_projections(
         potentially_unnormalized_candidates: bool,
     ) -> ProjectionMatchesProjection {
         let mut nested_obligations = Vec::new();
-        let infer_predicate = self.infcx.replace_bound_vars_with_fresh_vars(
+        let infer_predicate = self.infcx.instantiate_binder_with_fresh_vars(
             obligation.cause.span,
             LateBoundRegionConversionTime::HigherRankedType,
             env_predicate,
@@ -2339,7 +2339,7 @@ fn collect_predicates_for_types(
             .flat_map(|ty| {
                 let ty: ty::Binder<'tcx, Ty<'tcx>> = types.rebind(*ty); // <----/
 
-                let placeholder_ty = self.infcx.replace_bound_vars_with_placeholders(ty);
+                let placeholder_ty = self.infcx.instantiate_binder_with_placeholders(ty);
                 let Normalized { value: normalized_ty, mut obligations } =
                     ensure_sufficient_stack(|| {
                         project::normalize_with_depth(
@@ -2418,7 +2418,7 @@ fn match_impl(
         obligation: &TraitObligation<'tcx>,
     ) -> Result<Normalized<'tcx, SubstsRef<'tcx>>, ()> {
         let placeholder_obligation =
-            self.infcx.replace_bound_vars_with_placeholders(obligation.predicate);
+            self.infcx.instantiate_binder_with_placeholders(obligation.predicate);
         let placeholder_obligation_trait_ref = placeholder_obligation.trait_ref;
 
         let impl_substs = self.infcx.fresh_substs_for_item(obligation.cause.span, impl_def_id);
index e7bb30553736c492533962e8f576f1101a43e87b..3ede95e84313dde8cdc4e15a01dd8d4693bb6e3a 100644 (file)
@@ -310,47 +310,51 @@ fn clone(&self) -> Self {
 impl<I: Interner> PartialEq for TyKind<I> {
     #[inline]
     fn eq(&self, other: &TyKind<I>) -> bool {
-        tykind_discriminant(self) == tykind_discriminant(other)
-            && match (self, other) {
-                (Int(a_i), Int(b_i)) => a_i == b_i,
-                (Uint(a_u), Uint(b_u)) => a_u == b_u,
-                (Float(a_f), Float(b_f)) => a_f == b_f,
-                (Adt(a_d, a_s), Adt(b_d, b_s)) => a_d == b_d && a_s == b_s,
-                (Foreign(a_d), Foreign(b_d)) => a_d == b_d,
-                (Array(a_t, a_c), Array(b_t, b_c)) => a_t == b_t && a_c == b_c,
-                (Slice(a_t), Slice(b_t)) => a_t == b_t,
-                (RawPtr(a_t), RawPtr(b_t)) => a_t == b_t,
-                (Ref(a_r, a_t, a_m), Ref(b_r, b_t, b_m)) => a_r == b_r && a_t == b_t && a_m == b_m,
-                (FnDef(a_d, a_s), FnDef(b_d, b_s)) => a_d == b_d && a_s == b_s,
-                (FnPtr(a_s), FnPtr(b_s)) => a_s == b_s,
-                (Dynamic(a_p, a_r, a_repr), Dynamic(b_p, b_r, b_repr)) => {
-                    a_p == b_p && a_r == b_r && a_repr == b_repr
-                }
-                (Closure(a_d, a_s), Closure(b_d, b_s)) => a_d == b_d && a_s == b_s,
-                (Generator(a_d, a_s, a_m), Generator(b_d, b_s, b_m)) => {
-                    a_d == b_d && a_s == b_s && a_m == b_m
-                }
-                (GeneratorWitness(a_g), GeneratorWitness(b_g)) => a_g == b_g,
-                (
-                    &GeneratorWitnessMIR(ref a_d, ref a_s),
-                    &GeneratorWitnessMIR(ref b_d, ref b_s),
-                ) => a_d == b_d && a_s == b_s,
-                (Tuple(a_t), Tuple(b_t)) => a_t == b_t,
-                (Alias(a_i, a_p), Alias(b_i, b_p)) => a_i == b_i && a_p == b_p,
-                (Param(a_p), Param(b_p)) => a_p == b_p,
-                (Bound(a_d, a_b), Bound(b_d, b_b)) => a_d == b_d && a_b == b_b,
-                (Placeholder(a_p), Placeholder(b_p)) => a_p == b_p,
-                (Infer(a_t), Infer(b_t)) => a_t == b_t,
-                (Error(a_e), Error(b_e)) => a_e == b_e,
-                (Bool, Bool) | (Char, Char) | (Str, Str) | (Never, Never) => true,
-                _ => {
-                    debug_assert!(
-                        false,
-                        "This branch must be unreachable, maybe the match is missing an arm? self = self = {self:?}, other = {other:?}"
-                    );
-                    true
-                }
+        // You might expect this `match` to be preceded with this:
+        //
+        //   tykind_discriminant(self) == tykind_discriminant(other) &&
+        //
+        // but the data patterns in practice are such that a comparison
+        // succeeds 99%+ of the time, and it's faster to omit it.
+        match (self, other) {
+            (Int(a_i), Int(b_i)) => a_i == b_i,
+            (Uint(a_u), Uint(b_u)) => a_u == b_u,
+            (Float(a_f), Float(b_f)) => a_f == b_f,
+            (Adt(a_d, a_s), Adt(b_d, b_s)) => a_d == b_d && a_s == b_s,
+            (Foreign(a_d), Foreign(b_d)) => a_d == b_d,
+            (Array(a_t, a_c), Array(b_t, b_c)) => a_t == b_t && a_c == b_c,
+            (Slice(a_t), Slice(b_t)) => a_t == b_t,
+            (RawPtr(a_t), RawPtr(b_t)) => a_t == b_t,
+            (Ref(a_r, a_t, a_m), Ref(b_r, b_t, b_m)) => a_r == b_r && a_t == b_t && a_m == b_m,
+            (FnDef(a_d, a_s), FnDef(b_d, b_s)) => a_d == b_d && a_s == b_s,
+            (FnPtr(a_s), FnPtr(b_s)) => a_s == b_s,
+            (Dynamic(a_p, a_r, a_repr), Dynamic(b_p, b_r, b_repr)) => {
+                a_p == b_p && a_r == b_r && a_repr == b_repr
             }
+            (Closure(a_d, a_s), Closure(b_d, b_s)) => a_d == b_d && a_s == b_s,
+            (Generator(a_d, a_s, a_m), Generator(b_d, b_s, b_m)) => {
+                a_d == b_d && a_s == b_s && a_m == b_m
+            }
+            (GeneratorWitness(a_g), GeneratorWitness(b_g)) => a_g == b_g,
+            (&GeneratorWitnessMIR(ref a_d, ref a_s), &GeneratorWitnessMIR(ref b_d, ref b_s)) => {
+                a_d == b_d && a_s == b_s
+            }
+            (Tuple(a_t), Tuple(b_t)) => a_t == b_t,
+            (Alias(a_i, a_p), Alias(b_i, b_p)) => a_i == b_i && a_p == b_p,
+            (Param(a_p), Param(b_p)) => a_p == b_p,
+            (Bound(a_d, a_b), Bound(b_d, b_b)) => a_d == b_d && a_b == b_b,
+            (Placeholder(a_p), Placeholder(b_p)) => a_p == b_p,
+            (Infer(a_t), Infer(b_t)) => a_t == b_t,
+            (Error(a_e), Error(b_e)) => a_e == b_e,
+            (Bool, Bool) | (Char, Char) | (Str, Str) | (Never, Never) => true,
+            _ => {
+                debug_assert!(
+                    tykind_discriminant(self) != tykind_discriminant(other),
+                    "This branch must be unreachable, maybe the match is missing an arm? self = self = {self:?}, other = {other:?}"
+                );
+                false
+            }
+        }
     }
 }
 
@@ -408,7 +412,7 @@ fn cmp(&self, other: &TyKind<I>) -> Ordering {
                 (Error(a_e), Error(b_e)) => a_e.cmp(b_e),
                 (Bool, Bool) | (Char, Char) | (Str, Str) | (Never, Never) => Ordering::Equal,
                 _ => {
-                    debug_assert!(false, "This branch must be unreachable, maybe the match is missing an arm? self = self = {self:?}, other = {other:?}");
+                    debug_assert!(false, "This branch must be unreachable, maybe the match is missing an arm? self = {self:?}, other = {other:?}");
                     Ordering::Equal
                 }
             }
index 016f139a501a00da5749e941e4c1d47df2fdaccb..000b9bd0fab42408a790d5b811c06f94385eba8a 100644 (file)
@@ -41,6 +41,28 @@ pub unsafe fn awaken(self) -> &'a mut T {
         // SAFETY: our own safety conditions imply this reference is again unique.
         unsafe { &mut *self.ptr.as_ptr() }
     }
+
+    /// Borrows a new mutable reference from the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn reborrow(&mut self) -> &'a mut T {
+        // SAFETY: our own safety conditions imply this reference is again unique.
+        unsafe { &mut *self.ptr.as_ptr() }
+    }
+
+    /// Borrows a new shared reference from the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn reborrow_shared(&self) -> &'a T {
+        // SAFETY: our own safety conditions imply this reference is again unique.
+        unsafe { &*self.ptr.as_ptr() }
+    }
 }
 
 #[cfg(test)]
index 1d9c4460ec92a9537f9b7cf8c86a634cc7829474..386cd1a1657e26f0dd9934dee92af16020cfe9fa 100644 (file)
@@ -6,7 +6,7 @@
 use core::iter::{FromIterator, FusedIterator};
 use core::marker::PhantomData;
 use core::mem::{self, ManuallyDrop};
-use core::ops::{Index, RangeBounds};
+use core::ops::{Bound, Index, RangeBounds};
 use core::ptr;
 
 use crate::alloc::{Allocator, Global};
@@ -15,7 +15,7 @@
 use super::dedup_sorted_iter::DedupSortedIter;
 use super::navigate::{LazyLeafRange, LeafRange};
 use super::node::{self, marker, ForceResult::*, Handle, NodeRef, Root};
-use super::search::SearchResult::*;
+use super::search::{SearchBound, SearchResult::*};
 use super::set_val::SetValZST;
 
 mod entry;
@@ -2422,6 +2422,732 @@ pub const fn len(&self) -> usize {
     pub const fn is_empty(&self) -> bool {
         self.len() == 0
     }
+
+    /// Returns a [`Cursor`] pointing at the first element that is above the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the first
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.lower_bound(Bound::Excluded(&2));
+    /// assert_eq!(cursor.key(), Some(&3));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let root_node = match self.root.as_ref() {
+            None => return Cursor { current: None, root: None },
+            Some(root) => root.reborrow(),
+        };
+        let edge = root_node.lower_bound(SearchBound::from_range(bound));
+        Cursor { current: edge.next_kv().ok(), root: self.root.as_ref() }
+    }
+
+    /// Returns a [`CursorMut`] pointing at the first element that is above the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the first
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.lower_bound_mut(Bound::Excluded(&2));
+    /// assert_eq!(cursor.key(), Some(&3));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let (root, dormant_root) = DormantMutRef::new(&mut self.root);
+        let root_node = match root.as_mut() {
+            None => {
+                return CursorMut {
+                    current: None,
+                    root: dormant_root,
+                    length: &mut self.length,
+                    alloc: &mut *self.alloc,
+                };
+            }
+            Some(root) => root.borrow_mut(),
+        };
+        let edge = root_node.lower_bound(SearchBound::from_range(bound));
+        CursorMut {
+            current: edge.next_kv().ok(),
+            root: dormant_root,
+            length: &mut self.length,
+            alloc: &mut *self.alloc,
+        }
+    }
+
+    /// Returns a [`Cursor`] pointing at the last element that is below the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the last
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.upper_bound(Bound::Excluded(&3));
+    /// assert_eq!(cursor.key(), Some(&2));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let root_node = match self.root.as_ref() {
+            None => return Cursor { current: None, root: None },
+            Some(root) => root.reborrow(),
+        };
+        let edge = root_node.upper_bound(SearchBound::from_range(bound));
+        Cursor { current: edge.next_back_kv().ok(), root: self.root.as_ref() }
+    }
+
+    /// Returns a [`CursorMut`] pointing at the last element that is below the
+    /// given bound.
+    ///
+    /// If no such element exists then a cursor pointing at the "ghost"
+    /// non-element is returned.
+    ///
+    /// Passing [`Bound::Unbounded`] will return a cursor pointing at the last
+    /// element of the map.
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(btree_cursors)]
+    ///
+    /// use std::collections::BTreeMap;
+    /// use std::ops::Bound;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    /// a.insert(4, "c");
+    /// let cursor = a.upper_bound_mut(Bound::Excluded(&3));
+    /// assert_eq!(cursor.key(), Some(&2));
+    /// ```
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>
+    where
+        K: Borrow<Q> + Ord,
+        Q: Ord,
+    {
+        let (root, dormant_root) = DormantMutRef::new(&mut self.root);
+        let root_node = match root.as_mut() {
+            None => {
+                return CursorMut {
+                    current: None,
+                    root: dormant_root,
+                    length: &mut self.length,
+                    alloc: &mut *self.alloc,
+                };
+            }
+            Some(root) => root.borrow_mut(),
+        };
+        let edge = root_node.upper_bound(SearchBound::from_range(bound));
+        CursorMut {
+            current: edge.next_back_kv().ok(),
+            root: dormant_root,
+            length: &mut self.length,
+            alloc: &mut *self.alloc,
+        }
+    }
+}
+
+/// A cursor over a `BTreeMap`.
+///
+/// A `Cursor` is like an iterator, except that it can freely seek back-and-forth.
+///
+/// Cursors always point to an element in the tree, and index in a logically circular way.
+/// To accommodate this, there is a "ghost" non-element that yields `None` between the last and
+/// first elements of the tree.
+///
+/// A `Cursor` is created with the [`BTreeMap::lower_bound`] and [`BTreeMap::upper_bound`] methods.
+#[unstable(feature = "btree_cursors", issue = "107540")]
+pub struct Cursor<'a, K: 'a, V: 'a> {
+    current: Option<Handle<NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal>, marker::KV>>,
+    root: Option<&'a node::Root<K, V>>,
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K, V> Clone for Cursor<'_, K, V> {
+    fn clone(&self) -> Self {
+        let Cursor { current, root } = *self;
+        Cursor { current, root }
+    }
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K: Debug, V: Debug> Debug for Cursor<'_, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("Cursor").field(&self.key_value()).finish()
+    }
+}
+
+/// A cursor over a `BTreeMap` with editing operations.
+///
+/// A `Cursor` is like an iterator, except that it can freely seek back-and-forth, and can
+/// safely mutate the tree during iteration. This is because the lifetime of its yielded
+/// references is tied to its own lifetime, instead of just the underlying tree. This means
+/// cursors cannot yield multiple elements at once.
+///
+/// Cursors always point to an element in the tree, and index in a logically circular way.
+/// To accommodate this, there is a "ghost" non-element that yields `None` between the last and
+/// first elements of the tree.
+///
+/// A `Cursor` is created with the [`BTreeMap::lower_bound_mut`] and [`BTreeMap::upper_bound_mut`]
+/// methods.
+#[unstable(feature = "btree_cursors", issue = "107540")]
+pub struct CursorMut<
+    'a,
+    K: 'a,
+    V: 'a,
+    #[unstable(feature = "allocator_api", issue = "32838")] A = Global,
+> {
+    current: Option<Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>>,
+    root: DormantMutRef<'a, Option<node::Root<K, V>>>,
+    length: &'a mut usize,
+    alloc: &'a mut A,
+}
+
+#[unstable(feature = "btree_cursors", issue = "107540")]
+impl<K: Debug, V: Debug, A> Debug for CursorMut<'_, K, V, A> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("CursorMut").field(&self.key_value()).finish()
+    }
+}
+
+impl<'a, K, V> Cursor<'a, K, V> {
+    /// Moves the cursor to the next element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_next(&mut self) {
+        match self.current.take() {
+            None => {
+                self.current = self.root.and_then(|root| {
+                    root.reborrow().first_leaf_edge().forget_node_type().right_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_leaf_edge().next_kv().ok();
+            }
+        }
+    }
+
+    /// Moves the cursor to the previous element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_prev(&mut self) {
+        match self.current.take() {
+            None => {
+                self.current = self.root.and_then(|root| {
+                    root.reborrow().last_leaf_edge().forget_node_type().left_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_back_leaf_edge().next_back_kv().ok();
+            }
+        }
+    }
+
+    /// Returns a reference to the key of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key(&self) -> Option<&'a K> {
+        self.current.as_ref().map(|current| current.into_kv().0)
+    }
+
+    /// Returns a reference to the value of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value(&self) -> Option<&'a V> {
+        self.current.as_ref().map(|current| current.into_kv().1)
+    }
+
+    /// Returns a reference to the key and value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value(&self) -> Option<(&'a K, &'a V)> {
+        self.current.as_ref().map(|current| current.into_kv())
+    }
+
+    /// Returns a reference to the next element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_next(&self) -> Option<(&'a K, &'a V)> {
+        let mut next = self.clone();
+        next.move_next();
+        next.current.as_ref().map(|current| current.into_kv())
+    }
+
+    /// Returns a reference to the previous element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_prev(&self) -> Option<(&'a K, &'a V)> {
+        let mut prev = self.clone();
+        prev.move_prev();
+        prev.current.as_ref().map(|current| current.into_kv())
+    }
+}
+
+impl<'a, K, V, A> CursorMut<'a, K, V, A> {
+    /// Moves the cursor to the next element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_next(&mut self) {
+        match self.current.take() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                self.current = unsafe { self.root.reborrow() }.as_mut().and_then(|root| {
+                    root.borrow_mut().first_leaf_edge().forget_node_type().right_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_leaf_edge().next_kv().ok();
+            }
+        }
+    }
+
+    /// Moves the cursor to the previous element of the `BTreeMap`.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this will move it to
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this will move it to the "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn move_prev(&mut self) {
+        match self.current.take() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                self.current = unsafe { self.root.reborrow() }.as_mut().and_then(|root| {
+                    root.borrow_mut().last_leaf_edge().forget_node_type().left_kv().ok()
+                });
+            }
+            Some(current) => {
+                self.current = current.next_back_leaf_edge().next_back_kv().ok();
+            }
+        }
+    }
+
+    /// Returns a reference to the key of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key(&self) -> Option<&K> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv().0)
+    }
+
+    /// Returns a reference to the value of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value(&self) -> Option<&V> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv().1)
+    }
+
+    /// Returns a reference to the key and value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value(&self) -> Option<(&K, &V)> {
+        self.current.as_ref().map(|current| current.reborrow().into_kv())
+    }
+
+    /// Returns a mutable reference to the value of the element that the cursor
+    /// is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn value_mut(&mut self) -> Option<&mut V> {
+        self.current.as_mut().map(|current| current.kv_mut().1)
+    }
+
+    /// Returns a reference to the key and mutable reference to the value of the
+    /// element that the cursor is currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn key_value_mut(&mut self) -> Option<(&K, &mut V)> {
+        self.current.as_mut().map(|current| {
+            let (k, v) = current.kv_mut();
+            (&*k, v)
+        })
+    }
+
+    /// Returns a mutable reference to the of the element that the cursor is
+    /// currently pointing to.
+    ///
+    /// This returns `None` if the cursor is currently pointing to the
+    /// "ghost" non-element.
+    ///
+    /// # Safety
+    ///
+    /// This can be used to modify the key, but you must ensure that the
+    /// `BTreeMap` invariants are maintained. Specifically:
+    ///
+    /// * The key must remain unique within the tree.
+    /// * The key must remain in sorted order with regards to other elements in
+    ///   the tree.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn key_mut_unchecked(&mut self) -> Option<&mut K> {
+        self.current.as_mut().map(|current| current.kv_mut().0)
+    }
+
+    /// Returns a reference to the key and value of the next element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the first element of the `BTreeMap`. If it is pointing to the last
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_next(&mut self) -> Option<(&K, &mut V)> {
+        let (k, v) = match self.current {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                unsafe { self.root.reborrow() }
+                    .as_mut()?
+                    .borrow_mut()
+                    .first_leaf_edge()
+                    .next_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+            // SAFETY: We're not using this to mutate the tree.
+            Some(ref mut current) => {
+                unsafe { current.reborrow_mut() }.next_leaf_edge().next_kv().ok()?.into_kv_valmut()
+            }
+        };
+        Some((k, v))
+    }
+
+    /// Returns a reference to the key and value of the previous element.
+    ///
+    /// If the cursor is pointing to the "ghost" non-element then this returns
+    /// the last element of the `BTreeMap`. If it is pointing to the first
+    /// element of the `BTreeMap` then this returns `None`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn peek_prev(&mut self) -> Option<(&K, &mut V)> {
+        let (k, v) = match self.current.as_mut() {
+            None => {
+                // SAFETY: The previous borrow of root has ended.
+                unsafe { self.root.reborrow() }
+                    .as_mut()?
+                    .borrow_mut()
+                    .first_leaf_edge()
+                    .next_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+            Some(current) => {
+                // SAFETY: We're not using this to mutate the tree.
+                unsafe { current.reborrow_mut() }
+                    .next_back_leaf_edge()
+                    .next_back_kv()
+                    .ok()?
+                    .into_kv_valmut()
+            }
+        };
+        Some((k, v))
+    }
+
+    /// Returns a read-only cursor pointing to the current element.
+    ///
+    /// The lifetime of the returned `Cursor` is bound to that of the
+    /// `CursorMut`, which means it cannot outlive the `CursorMut` and that the
+    /// `CursorMut` is frozen for the lifetime of the `Cursor`.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn as_cursor(&self) -> Cursor<'_, K, V> {
+        Cursor {
+            // SAFETY: The tree is immutable while the cursor exists.
+            root: unsafe { self.root.reborrow_shared().as_ref() },
+            current: self.current.as_ref().map(|current| current.reborrow()),
+        }
+    }
+}
+
+// Now the tree editing operations
+impl<'a, K: Ord, V, A: Allocator + Clone> CursorMut<'a, K, V, A> {
+    /// Inserts a new element into the `BTreeMap` after the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the front of the `BTreeMap`.
+    ///
+    /// # Safety
+    ///
+    /// You must ensure that the `BTreeMap` invariants are maintained.
+    /// Specifically:
+    ///
+    /// * The key of the newly inserted element must be unique in the tree.
+    /// * All keys in the tree must remain in sorted order.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn insert_after_unchecked(&mut self, key: K, value: V) {
+        let edge = match self.current.take() {
+            None => {
+                // SAFETY: We have no other reference to the tree.
+                match unsafe { self.root.reborrow() } {
+                    root @ None => {
+                        // Tree is empty, allocate a new root.
+                        let mut node = NodeRef::new_leaf(self.alloc.clone());
+                        node.borrow_mut().push(key, value);
+                        *root = Some(node.forget_type());
+                        *self.length += 1;
+                        return;
+                    }
+                    Some(root) => root.borrow_mut().first_leaf_edge(),
+                }
+            }
+            Some(current) => current.next_leaf_edge(),
+        };
+
+        let handle = edge.insert_recursing(key, value, self.alloc.clone(), |ins| {
+            drop(ins.left);
+            // SAFETY: The handle to the newly inserted value is always on a
+            // leaf node, so adding a new root node doesn't invalidate it.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.push_internal_level(self.alloc.clone()).push(ins.kv.0, ins.kv.1, ins.right)
+        });
+        self.current = handle.left_edge().next_back_kv().ok();
+        *self.length += 1;
+    }
+
+    /// Inserts a new element into the `BTreeMap` before the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the end of the `BTreeMap`.
+    ///
+    /// # Safety
+    ///
+    /// You must ensure that the `BTreeMap` invariants are maintained.
+    /// Specifically:
+    ///
+    /// * The key of the newly inserted element must be unique in the tree.
+    /// * All keys in the tree must remain in sorted order.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub unsafe fn insert_before_unchecked(&mut self, key: K, value: V) {
+        let edge = match self.current.take() {
+            None => {
+                // SAFETY: We have no other reference to the tree.
+                match unsafe { self.root.reborrow() } {
+                    root @ None => {
+                        // Tree is empty, allocate a new root.
+                        let mut node = NodeRef::new_leaf(self.alloc.clone());
+                        node.borrow_mut().push(key, value);
+                        *root = Some(node.forget_type());
+                        *self.length += 1;
+                        return;
+                    }
+                    Some(root) => root.borrow_mut().last_leaf_edge(),
+                }
+            }
+            Some(current) => current.next_back_leaf_edge(),
+        };
+
+        let handle = edge.insert_recursing(key, value, self.alloc.clone(), |ins| {
+            drop(ins.left);
+            // SAFETY: The handle to the newly inserted value is always on a
+            // leaf node, so adding a new root node doesn't invalidate it.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.push_internal_level(self.alloc.clone()).push(ins.kv.0, ins.kv.1, ins.right)
+        });
+        self.current = handle.right_edge().next_kv().ok();
+        *self.length += 1;
+    }
+
+    /// Inserts a new element into the `BTreeMap` after the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the front of the `BTreeMap`.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if:
+    /// - the given key compares less than or equal to the current element (if
+    ///   any).
+    /// - the given key compares greater than or equal to the next element (if
+    ///   any).
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn insert_after(&mut self, key: K, value: V) {
+        if let Some(current) = self.key() {
+            if &key <= current {
+                panic!("key must be ordered above the current element");
+            }
+        }
+        if let Some((next, _)) = self.peek_prev() {
+            if &key >= next {
+                panic!("key must be ordered below the next element");
+            }
+        }
+        unsafe {
+            self.insert_after_unchecked(key, value);
+        }
+    }
+
+    /// Inserts a new element into the `BTreeMap` before the current one.
+    ///
+    /// If the cursor is pointing at the "ghost" non-element then the new element is
+    /// inserted at the end of the `BTreeMap`.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if:
+    /// - the given key compares greater than or equal to the current element
+    ///   (if any).
+    /// - the given key compares less than or equal to the previous element (if
+    ///   any).
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn insert_before(&mut self, key: K, value: V) {
+        if let Some(current) = self.key() {
+            if &key >= current {
+                panic!("key must be ordered below the current element");
+            }
+        }
+        if let Some((prev, _)) = self.peek_prev() {
+            if &key <= prev {
+                panic!("key must be ordered above the previous element");
+            }
+        }
+        unsafe {
+            self.insert_before_unchecked(key, value);
+        }
+    }
+
+    /// Removes the current element from the `BTreeMap`.
+    ///
+    /// The element that was removed is returned, and the cursor is
+    /// moved to point to the next element in the `BTreeMap`.
+    ///
+    /// If the cursor is currently pointing to the "ghost" non-element then no element
+    /// is removed and `None` is returned. The cursor is not moved in this case.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn remove_current(&mut self) -> Option<(K, V)> {
+        let current = self.current.take()?;
+        let mut emptied_internal_root = false;
+        let (kv, pos) =
+            current.remove_kv_tracking(|| emptied_internal_root = true, self.alloc.clone());
+        self.current = pos.next_kv().ok();
+        *self.length -= 1;
+        if emptied_internal_root {
+            // SAFETY: This is safe since current does not point within the now
+            // empty root node.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.pop_internal_level(self.alloc.clone());
+        }
+        Some(kv)
+    }
+
+    /// Removes the current element from the `BTreeMap`.
+    ///
+    /// The element that was removed is returned, and the cursor is
+    /// moved to point to the previous element in the `BTreeMap`.
+    ///
+    /// If the cursor is currently pointing to the "ghost" non-element then no element
+    /// is removed and `None` is returned. The cursor is not moved in this case.
+    #[unstable(feature = "btree_cursors", issue = "107540")]
+    pub fn remove_current_and_move_back(&mut self) -> Option<(K, V)> {
+        let current = self.current.take()?;
+        let mut emptied_internal_root = false;
+        let (kv, pos) =
+            current.remove_kv_tracking(|| emptied_internal_root = true, self.alloc.clone());
+        self.current = pos.next_back_kv().ok();
+        *self.length -= 1;
+        if emptied_internal_root {
+            // SAFETY: This is safe since current does not point within the now
+            // empty root node.
+            let root = unsafe { self.root.reborrow().as_mut().unwrap() };
+            root.pop_internal_level(self.alloc.clone());
+        }
+        Some(kv)
+    }
 }
 
 #[cfg(test)]
index 370b58864af8f3f4f9d1d2c3af7bd054331f3c79..e9366eec9cec3028a05635b62672beed4602f5d3 100644 (file)
@@ -347,7 +347,7 @@ pub fn into_key(self) -> K {
     /// assert_eq!(map["poneyland"], 37);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub fn insert(self, value: V) -> &'a mut V {
+    pub fn insert(mut self, value: V) -> &'a mut V {
         let out_ptr = match self.handle {
             None => {
                 // SAFETY: There is no tree yet so no reference to it exists.
@@ -358,25 +358,27 @@ pub fn insert(self, value: V) -> &'a mut V {
                 map.length = 1;
                 val_ptr
             }
-            Some(handle) => match handle.insert_recursing(self.key, value, self.alloc.clone()) {
-                (None, val_ptr) => {
-                    // SAFETY: We have consumed self.handle.
-                    let map = unsafe { self.dormant_map.awaken() };
-                    map.length += 1;
-                    val_ptr
-                }
-                (Some(ins), val_ptr) => {
-                    drop(ins.left);
-                    // SAFETY: We have consumed self.handle and dropped the
-                    // remaining reference to the tree, ins.left.
-                    let map = unsafe { self.dormant_map.awaken() };
-                    let root = map.root.as_mut().unwrap(); // same as ins.left
-                    root.push_internal_level(self.alloc).push(ins.kv.0, ins.kv.1, ins.right);
-                    map.length += 1;
-                    val_ptr
-                }
-            },
+            Some(handle) => {
+                let new_handle =
+                    handle.insert_recursing(self.key, value, self.alloc.clone(), |ins| {
+                        drop(ins.left);
+                        // SAFETY: Pushing a new root node doesn't invalidate
+                        // handles to existing nodes.
+                        let map = unsafe { self.dormant_map.reborrow() };
+                        let root = map.root.as_mut().unwrap(); // same as ins.left
+                        root.push_internal_level(self.alloc).push(ins.kv.0, ins.kv.1, ins.right)
+                    });
+
+                // Get the pointer to the value
+                let val_ptr = new_handle.into_val_mut();
+
+                // SAFETY: We have consumed self.handle.
+                let map = unsafe { self.dormant_map.awaken() };
+                map.length += 1;
+                val_ptr
+            }
         };
+
         // Now that we have finished growing the tree using borrowed references,
         // dereference the pointer to a part of it, that we picked up along the way.
         unsafe { &mut *out_ptr }
index 700b1463bfd51f961e8b7bb2cb43e991c9473d4e..76c2f27b46634a885a663a6ba53595a74f79702c 100644 (file)
@@ -2336,3 +2336,52 @@ fn from_array() {
     let unordered_duplicates = BTreeMap::from([(3, 4), (1, 2), (1, 2)]);
     assert_eq!(map, unordered_duplicates);
 }
+
+#[test]
+fn test_cursor() {
+    let map = BTreeMap::from([(1, 'a'), (2, 'b'), (3, 'c')]);
+
+    let mut cur = map.lower_bound(Bound::Unbounded);
+    assert_eq!(cur.key(), Some(&1));
+    cur.move_next();
+    assert_eq!(cur.key(), Some(&2));
+    assert_eq!(cur.peek_next(), Some((&3, &'c')));
+    cur.move_prev();
+    assert_eq!(cur.key(), Some(&1));
+    assert_eq!(cur.peek_prev(), None);
+
+    let mut cur = map.upper_bound(Bound::Excluded(&1));
+    assert_eq!(cur.key(), None);
+    cur.move_next();
+    assert_eq!(cur.key(), Some(&1));
+    cur.move_prev();
+    assert_eq!(cur.key(), None);
+    assert_eq!(cur.peek_prev(), Some((&3, &'c')));
+}
+
+#[test]
+fn test_cursor_mut() {
+    let mut map = BTreeMap::from([(1, 'a'), (3, 'c'), (5, 'e')]);
+    let mut cur = map.lower_bound_mut(Bound::Excluded(&3));
+    assert_eq!(cur.key(), Some(&5));
+    cur.insert_before(4, 'd');
+    assert_eq!(cur.key(), Some(&5));
+    assert_eq!(cur.peek_prev(), Some((&4, &mut 'd')));
+    cur.move_next();
+    assert_eq!(cur.key(), None);
+    cur.insert_before(6, 'f');
+    assert_eq!(cur.key(), None);
+    assert_eq!(cur.remove_current(), None);
+    assert_eq!(cur.key(), None);
+    cur.insert_after(0, '?');
+    assert_eq!(cur.key(), None);
+    assert_eq!(map, BTreeMap::from([(0, '?'), (1, 'a'), (3, 'c'), (4, 'd'), (5, 'e'), (6, 'f')]));
+
+    let mut cur = map.upper_bound_mut(Bound::Included(&5));
+    assert_eq!(cur.key(), Some(&5));
+    assert_eq!(cur.remove_current(), Some((5, 'e')));
+    assert_eq!(cur.key(), Some(&6));
+    assert_eq!(cur.remove_current_and_move_back(), Some((6, 'f')));
+    assert_eq!(cur.key(), Some(&4));
+    assert_eq!(map, BTreeMap::from([(0, '?'), (1, 'a'), (3, 'c'), (4, 'd')]));
+}
index 1e33c1e64d66e085a09cc51b86210556d92f4b11..b890717e50b2544b62dfbc73312ba9e975db3225 100644 (file)
@@ -4,6 +4,7 @@
 use core::ptr;
 
 use super::node::{marker, ForceResult::*, Handle, NodeRef};
+use super::search::SearchBound;
 
 use crate::alloc::Allocator;
 // `front` and `back` are always both `None` or both `Some`.
@@ -386,7 +387,7 @@ pub fn next_kv(
     /// Given a leaf edge handle, returns [`Result::Ok`] with a handle to the neighboring KV
     /// on the left side, which is either in the same leaf node or in an ancestor node.
     /// If the leaf edge is the first one in the tree, returns [`Result::Err`] with the root node.
-    fn next_back_kv(
+    pub fn next_back_kv(
         self,
     ) -> Result<
         Handle<NodeRef<BorrowType, K, V, marker::LeafOrInternal>, marker::KV>,
@@ -707,7 +708,9 @@ pub fn next_leaf_edge(self) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, m
     }
 
     /// Returns the leaf edge closest to a KV for backward navigation.
-    fn next_back_leaf_edge(self) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> {
+    pub fn next_back_leaf_edge(
+        self,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> {
         match self.force() {
             Leaf(leaf_kv) => leaf_kv.left_edge(),
             Internal(internal_kv) => {
@@ -717,3 +720,51 @@ fn next_back_leaf_edge(self) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>,
         }
     }
 }
+
+impl<BorrowType: marker::BorrowType, K, V> NodeRef<BorrowType, K, V, marker::LeafOrInternal> {
+    /// Returns the leaf edge corresponding to the first point at which the
+    /// given bound is true.
+    pub fn lower_bound<Q: ?Sized>(
+        self,
+        mut bound: SearchBound<&Q>,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>
+    where
+        Q: Ord,
+        K: Borrow<Q>,
+    {
+        let mut node = self;
+        loop {
+            let (edge, new_bound) = node.find_lower_bound_edge(bound);
+            match edge.force() {
+                Leaf(edge) => return edge,
+                Internal(edge) => {
+                    node = edge.descend();
+                    bound = new_bound;
+                }
+            }
+        }
+    }
+
+    /// Returns the leaf edge corresponding to the last point at which the
+    /// given bound is true.
+    pub fn upper_bound<Q: ?Sized>(
+        self,
+        mut bound: SearchBound<&Q>,
+    ) -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>
+    where
+        Q: Ord,
+        K: Borrow<Q>,
+    {
+        let mut node = self;
+        loop {
+            let (edge, new_bound) = node.find_upper_bound_edge(bound);
+            match edge.force() {
+                Leaf(edge) => return edge,
+                Internal(edge) => {
+                    node = edge.descend();
+                    bound = new_bound;
+                }
+            }
+        }
+    }
+}
index 6912466448fab444c6860425ba5970a41ef75a8b..3233a575ecf254e73fe18c3d55679716d276f96c 100644 (file)
@@ -442,6 +442,24 @@ fn into_leaf_mut(mut self) -> &'a mut LeafNode<K, V> {
         // SAFETY: we have exclusive access to the entire node.
         unsafe { &mut *ptr }
     }
+
+    /// Returns a dormant copy of this node with its lifetime erased which can
+    /// be reawakened later.
+    pub fn dormant(&self) -> NodeRef<marker::DormantMut, K, V, Type> {
+        NodeRef { height: self.height, node: self.node, _marker: PhantomData }
+    }
+}
+
+impl<K, V, Type> NodeRef<marker::DormantMut, K, V, Type> {
+    /// Revert to the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn awaken<'a>(self) -> NodeRef<marker::Mut<'a>, K, V, Type> {
+        NodeRef { height: self.height, node: self.node, _marker: PhantomData }
+    }
 }
 
 impl<K, V, Type> NodeRef<marker::Dying, K, V, Type> {
@@ -798,6 +816,25 @@ pub unsafe fn reborrow_mut(
         // We can't use Handle::new_kv or Handle::new_edge because we don't know our type
         Handle { node: unsafe { self.node.reborrow_mut() }, idx: self.idx, _marker: PhantomData }
     }
+
+    /// Returns a dormant copy of this handle which can be reawakened later.
+    ///
+    /// See `DormantMutRef` for more details.
+    pub fn dormant(&self) -> Handle<NodeRef<marker::DormantMut, K, V, NodeType>, HandleType> {
+        Handle { node: self.node.dormant(), idx: self.idx, _marker: PhantomData }
+    }
+}
+
+impl<K, V, NodeType, HandleType> Handle<NodeRef<marker::DormantMut, K, V, NodeType>, HandleType> {
+    /// Revert to the unique borrow initially captured.
+    ///
+    /// # Safety
+    ///
+    /// The reborrow must have ended, i.e., the reference returned by `new` and
+    /// all pointers and references derived from it, must not be used anymore.
+    pub unsafe fn awaken<'a>(self) -> Handle<NodeRef<marker::Mut<'a>, K, V, NodeType>, HandleType> {
+        Handle { node: unsafe { self.node.awaken() }, idx: self.idx, _marker: PhantomData }
+    }
 }
 
 impl<BorrowType, K, V, NodeType> Handle<NodeRef<BorrowType, K, V, NodeType>, marker::Edge> {
@@ -851,9 +888,11 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
     /// Inserts a new key-value pair between the key-value pairs to the right and left of
     /// this edge. This method assumes that there is enough space in the node for the new
     /// pair to fit.
-    ///
-    /// The returned pointer points to the inserted value.
-    fn insert_fit(&mut self, key: K, val: V) -> *mut V {
+    unsafe fn insert_fit(
+        mut self,
+        key: K,
+        val: V,
+    ) -> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::KV> {
         debug_assert!(self.node.len() < CAPACITY);
         let new_len = self.node.len() + 1;
 
@@ -862,7 +901,7 @@ fn insert_fit(&mut self, key: K, val: V) -> *mut V {
             slice_insert(self.node.val_area_mut(..new_len), self.idx, val);
             *self.node.len_mut() = new_len as u16;
 
-            self.node.val_area_mut(self.idx).assume_init_mut()
+            Handle::new_kv(self.node, self.idx)
         }
     }
 }
@@ -871,21 +910,26 @@ impl<'a, K: 'a, V: 'a> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, mark
     /// Inserts a new key-value pair between the key-value pairs to the right and left of
     /// this edge. This method splits the node if there isn't enough room.
     ///
-    /// The returned pointer points to the inserted value.
+    /// Returns a dormant handle to the inserted node which can be reawakened
+    /// once splitting is complete.
     fn insert<A: Allocator + Clone>(
-        mut self,
+        self,
         key: K,
         val: V,
         alloc: A,
-    ) -> (Option<SplitResult<'a, K, V, marker::Leaf>>, *mut V) {
+    ) -> (
+        Option<SplitResult<'a, K, V, marker::Leaf>>,
+        Handle<NodeRef<marker::DormantMut, K, V, marker::Leaf>, marker::KV>,
+    ) {
         if self.node.len() < CAPACITY {
-            let val_ptr = self.insert_fit(key, val);
-            (None, val_ptr)
+            // SAFETY: There is enough space in the node for insertion.
+            let handle = unsafe { self.insert_fit(key, val) };
+            (None, handle.dormant())
         } else {
             let (middle_kv_idx, insertion) = splitpoint(self.idx);
             let middle = unsafe { Handle::new_kv(self.node, middle_kv_idx) };
             let mut result = middle.split(alloc);
-            let mut insertion_edge = match insertion {
+            let insertion_edge = match insertion {
                 LeftOrRight::Left(insert_idx) => unsafe {
                     Handle::new_edge(result.left.reborrow_mut(), insert_idx)
                 },
@@ -893,8 +937,10 @@ fn insert<A: Allocator + Clone>(
                     Handle::new_edge(result.right.borrow_mut(), insert_idx)
                 },
             };
-            let val_ptr = insertion_edge.insert_fit(key, val);
-            (Some(result), val_ptr)
+            // SAFETY: We just split the node, so there is enough space for
+            // insertion.
+            let handle = unsafe { insertion_edge.insert_fit(key, val).dormant() };
+            (Some(result), handle)
         }
     }
 }
@@ -976,21 +1022,31 @@ pub fn insert_recursing<A: Allocator + Clone>(
         key: K,
         value: V,
         alloc: A,
-    ) -> (Option<SplitResult<'a, K, V, marker::LeafOrInternal>>, *mut V) {
-        let (mut split, val_ptr) = match self.insert(key, value, alloc.clone()) {
-            (None, val_ptr) => return (None, val_ptr),
-            (Some(split), val_ptr) => (split.forget_node_type(), val_ptr),
+        split_root: impl FnOnce(SplitResult<'a, K, V, marker::LeafOrInternal>),
+    ) -> Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::KV> {
+        let (mut split, handle) = match self.insert(key, value, alloc.clone()) {
+            // SAFETY: we have finished splitting and can now re-awaken the
+            // handle to the inserted element.
+            (None, handle) => return unsafe { handle.awaken() },
+            (Some(split), handle) => (split.forget_node_type(), handle),
         };
 
         loop {
             split = match split.left.ascend() {
                 Ok(parent) => {
                     match parent.insert(split.kv.0, split.kv.1, split.right, alloc.clone()) {
-                        None => return (None, val_ptr),
+                        // SAFETY: we have finished splitting and can now re-awaken the
+                        // handle to the inserted element.
+                        None => return unsafe { handle.awaken() },
                         Some(split) => split.forget_node_type(),
                     }
                 }
-                Err(root) => return (Some(SplitResult { left: root, ..split }), val_ptr),
+                Err(root) => {
+                    split_root(SplitResult { left: root, ..split });
+                    // SAFETY: we have finished splitting and can now re-awaken the
+                    // handle to the inserted element.
+                    return unsafe { handle.awaken() };
+                }
             };
         }
     }
@@ -1043,6 +1099,14 @@ pub fn into_val_mut(self) -> &'a mut V {
         let leaf = self.node.into_leaf_mut();
         unsafe { leaf.vals.get_unchecked_mut(self.idx).assume_init_mut() }
     }
+
+    pub fn into_kv_valmut(self) -> (&'a K, &'a mut V) {
+        debug_assert!(self.idx < self.node.len());
+        let leaf = self.node.into_leaf_mut();
+        let k = unsafe { leaf.keys.get_unchecked(self.idx).assume_init_ref() };
+        let v = unsafe { leaf.vals.get_unchecked_mut(self.idx).assume_init_mut() };
+        (k, v)
+    }
 }
 
 impl<'a, K, V, NodeType> Handle<NodeRef<marker::ValMut<'a>, K, V, NodeType>, marker::KV> {
@@ -1667,6 +1731,7 @@ pub enum LeafOrInternal {}
 
     pub enum Owned {}
     pub enum Dying {}
+    pub enum DormantMut {}
     pub struct Immut<'a>(PhantomData<&'a ()>);
     pub struct Mut<'a>(PhantomData<&'a mut ()>);
     pub struct ValMut<'a>(PhantomData<&'a mut ()>);
@@ -1688,6 +1753,7 @@ impl BorrowType for Dying {}
     impl<'a> BorrowType for Immut<'a> {}
     impl<'a> BorrowType for Mut<'a> {}
     impl<'a> BorrowType for ValMut<'a> {}
+    impl BorrowType for DormantMut {}
 
     pub enum KV {}
     pub enum Edge {}
index 76dabfb429dd503ab945ff002028f0a7f2d375dc..e9cc3875f683b1cf09c301775eb249ce87734920 100644 (file)
 #![feature(const_eval_select)]
 #![feature(const_pin)]
 #![feature(const_waker)]
-#![feature(cstr_from_bytes_until_nul)]
 #![feature(dispatch_from_dyn)]
 #![feature(error_generic_member_access)]
 #![feature(error_in_core)]
index d2fac23ff18be7542729e0b6793d796daad17dd5..e11a5e99184cb47bdee8bdc8a9d9c92ee2319268 100644 (file)
@@ -505,7 +505,7 @@ fn description(&self) -> &str {
     }
 }
 
-#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
+#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
 impl Error for crate::ffi::FromBytesUntilNulError {}
 
 #[unstable(feature = "get_many_mut", issue = "104642")]
index 15dd9ea7e803657d9122f63c95fd2db806b1fb04..82e5fa75ded841e0299b63574cf4a658066020ec 100644 (file)
@@ -150,10 +150,10 @@ pub fn __description(&self) -> &str {
 /// This error is created by the [`CStr::from_bytes_until_nul`] method.
 ///
 #[derive(Clone, PartialEq, Eq, Debug)]
-#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
+#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
 pub struct FromBytesUntilNulError(());
 
-#[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
+#[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
 impl fmt::Display for FromBytesUntilNulError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "data provided does not contain a nul")
@@ -306,8 +306,6 @@ fn strlen_rt(s: *const c_char) -> usize {
     ///
     /// # Examples
     /// ```
-    /// #![feature(cstr_from_bytes_until_nul)]
-    ///
     /// use std::ffi::CStr;
     ///
     /// let mut buffer = [0u8; 16];
@@ -322,8 +320,9 @@ fn strlen_rt(s: *const c_char) -> usize {
     /// assert_eq!(c_str.to_str().unwrap(), "AAAAAAAA");
     /// ```
     ///
-    #[unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
-    #[rustc_const_unstable(feature = "cstr_from_bytes_until_nul", issue = "95027")]
+    #[rustc_allow_const_fn_unstable(const_slice_index)]
+    #[stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "cstr_from_bytes_until_nul", since = "CURRENT_RUSTC_VERSION")]
     pub const fn from_bytes_until_nul(bytes: &[u8]) -> Result<&CStr, FromBytesUntilNulError> {
         let nul_pos = memchr::memchr(0, bytes);
         match nul_pos {
index c848c2e18e9b5293a132e2c926cb8ae3e7508b8c..98c8349eb602484c795f9514f697616558086b53 100644 (file)
 /// bytes where the borrow propagated all the way to the most significant
 /// bit."
 #[inline]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 const fn contains_zero_byte(x: usize) -> bool {
     x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != 0
 }
 
-#[cfg(target_pointer_width = "16")]
 #[inline]
+#[cfg(target_pointer_width = "16")]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 const fn repeat_byte(b: u8) -> usize {
     (b as usize) << 8 | b as usize
 }
 
-#[cfg(not(target_pointer_width = "16"))]
 #[inline]
+#[cfg(not(target_pointer_width = "16"))]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 const fn repeat_byte(b: u8) -> usize {
     (b as usize) * (usize::MAX / 255)
 }
 
 /// Returns the first index matching the byte `x` in `text`.
-#[must_use]
 #[inline]
+#[must_use]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
     // Fast path for small slices.
     if text.len() < 2 * USIZE_BYTES {
@@ -45,6 +49,7 @@ pub const fn memchr(x: u8, text: &[u8]) -> Option<usize> {
 }
 
 #[inline]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
     let mut i = 0;
 
@@ -60,6 +65,10 @@ const fn memchr_naive(x: u8, text: &[u8]) -> Option<usize> {
     None
 }
 
+#[rustc_allow_const_fn_unstable(const_cmp)]
+#[rustc_allow_const_fn_unstable(const_slice_index)]
+#[rustc_allow_const_fn_unstable(const_align_offset)]
+#[rustc_const_stable(feature = "const_memchr", since = "1.65.0")]
 const fn memchr_aligned(x: u8, text: &[u8]) -> Option<usize> {
     // Scan for a single byte value by reading two `usize` words at a time.
     //
index 324d698eaeb1d129a772f7bb31db616aee342b62..7f07e4fddef77ca7f0c0e51f5352a922b5d5b776 100644 (file)
@@ -102,7 +102,7 @@ enum ErrorData<C> {
 /// portability.
 ///
 /// [`into`]: Into::into
-#[unstable(feature = "raw_os_error_ty", issue = "none")]
+#[unstable(feature = "raw_os_error_ty", issue = "107792")]
 pub type RawOsError = i32;
 
 // `#[repr(align(4))]` is probably redundant, it should have that value or
index 5907ba5d5fbf3ab8dd8495cd2619aa25f5b7de09..b2b6d86134b6292bff70b20964bd26584b1bcac8 100644 (file)
 
 #[stable(feature = "bufwriter_into_parts", since = "1.56.0")]
 pub use self::buffered::WriterPanicked;
-#[unstable(feature = "raw_os_error_ty", issue = "none")]
+#[unstable(feature = "raw_os_error_ty", issue = "107792")]
 pub use self::error::RawOsError;
 pub(crate) use self::stdio::attempt_print_to_stderr;
 #[unstable(feature = "internal_output_capture", issue = "none")]
index 762f7a7c9a1a0a5907b4c6f39a9bb29b8796f96b..cd9f74820ae9b576fbe529b0b6995ba23fcbd90f 100644 (file)
 #![feature(char_error_internals)]
 #![feature(char_internals)]
 #![feature(core_intrinsics)]
-#![feature(cstr_from_bytes_until_nul)]
 #![feature(cstr_internals)]
 #![feature(duration_constants)]
 #![feature(error_generic_member_access)]
index c41e093a7e5c6442f7022cd09d7f587f680af185..439b8d52a2d8673b62486a2c75da854f65ef2386 100644 (file)
@@ -396,6 +396,14 @@ fn as_fd(&self) -> BorrowedFd<'_> {
     }
 }
 
+#[stable(feature = "asfd_rc", since = "CURRENT_RUSTC_VERSION")]
+impl<T: AsFd> AsFd for crate::rc::Rc<T> {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        (**self).as_fd()
+    }
+}
+
 #[stable(feature = "asfd_ptrs", since = "1.64.0")]
 impl<T: AsFd> AsFd for Box<T> {
     #[inline]
index f92a05066706d276cb98599992d518e37ee4b6a4..c138162f1ab08b5cad949162ec687a9eb1ea4467 100644 (file)
@@ -244,6 +244,14 @@ fn as_raw_fd(&self) -> RawFd {
     }
 }
 
+#[stable(feature = "asfd_rc", since = "CURRENT_RUSTC_VERSION")]
+impl<T: AsRawFd> AsRawFd for crate::rc::Rc<T> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        (**self).as_raw_fd()
+    }
+}
+
 #[stable(feature = "asrawfd_ptrs", since = "1.63.0")]
 impl<T: AsRawFd> AsRawFd for Box<T> {
     #[inline]
index 5b19a658fb5432c0d4983860fd449f19313ac2d3..c298817895cd17c00cfdea87d99b01f5c4a4946e 100644 (file)
@@ -87,14 +87,16 @@ def _download(path, url, probably_big, verbose, exception):
         # If curl is not present on Win32, we should not sys.exit
         #   but raise `CalledProcessError` or `OSError` instead
         require(["curl", "--version"], exception=platform_is_win32)
-        run(["curl", option,
-             "-L", # Follow redirect.
-             "-y", "30", "-Y", "10",    # timeout if speed is < 10 bytes/sec for > 30 seconds
-             "--connect-timeout", "30",  # timeout if cannot connect within 30 seconds
-             "--retry", "3", "-Sf", "-o", path, url],
-            verbose=verbose,
-            exception=True, # Will raise RuntimeError on failure
-        )
+        with open(path, "wb") as outfile:
+            run(["curl", option,
+                "-L", # Follow redirect.
+                "-y", "30", "-Y", "10",    # timeout if speed is < 10 bytes/sec for > 30 seconds
+                "--connect-timeout", "30",  # timeout if cannot connect within 30 seconds
+                "--retry", "3", "-Sf", url],
+                stdout=outfile,    #Implements cli redirect operator '>'
+                verbose=verbose,
+                exception=True, # Will raise RuntimeError on failure
+            )
     except (subprocess.CalledProcessError, OSError, RuntimeError):
         # see http://serverfault.com/questions/301128/how-to-download
         if platform_is_win32:
index 01da3b24c7c4f3cba6ed2123a4a3ddfb2cb21a21..83c07f63d10ab22413adc3b12d2ed4bc43394cf3 100644 (file)
@@ -1 +1 @@
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\ No newline at end of file
+<svg xmlns="http://www.w3.org/2000/svg" width="27.434" height="29.5" enable-background="new 0 0 27.434 29.5" viewBox="0 0 27.434 29.5"><path d="M27.316 18.39a2.696 2.696 0 0 0-.98-1.46 1.62 1.62 0 0 1-.016-.762l.035-.176v-1.191c0-1.246-.003-1.278-.046-1.473a1.717 1.717 0 0 1 .007-.805c.477-.343.829-.859.997-1.472.257-.957.074-2.094-.508-3.117l-.594-1.032c-.746-1.304-1.965-2.117-3.18-2.117-.379 0-.75.078-1.086.235a1.958 1.958 0 0 1-.855-.391l-.102-.082-.117-.063-1.855-1.07-.094-.055-.106-.043c-.378-.156-.66-.41-.77-.554C17.919 1.172 16.349 0 14.297 0h-1.155c-2.043 0-3.61 1.152-3.75 2.723-.114.14-.391.382-.758.527l-.102.04-.094.05-1.94 1.066-.134.074-.117.094a2.019 2.019 0 0 1-.832.403 2.518 2.518 0 0 0-1.008-.211c-1.199 0-2.414.82-3.168 2.14l-.59 1.032c-.41.718-.64 1.523-.64 2.257-.004.953.36 1.758 1.012 2.258.035.152.058.445-.016.785-.04.168-.063.282-.063 1.563 0 1.148 0 1.148.016 1.261l.008.075.015.074c.075.344.047.64.012.8-.644.5-1.004 1.302-.992 2.259.008.726.238 1.52.648 2.242l.59 1.027c.758 1.332 1.965 2.16 3.149 2.16.324 0 .644-.062.937-.187.168.039.492.156.813.418l.11.086.124.07 2.047 1.156.102.059.105.043c.363.144.648.379.766.52.164 1.519 1.718 2.632 3.746 2.632h1.156c2.035 0 3.598-1.133 3.746-2.672.117-.144.402-.394.773-.55l.114-.047.101-.063 1.961-1.156.106-.063.097-.078c.309-.246.653-.37.832-.398.313.136.66.21 1.016.21 1.2 0 2.41-.82 3.164-2.14l.594-1.031c.59-1.028.777-2.164.52-3.117Zm-2.043 2.247-.59 1.031c-.437.766-1.105 1.25-1.636 1.25a.7.7 0 0 1-.371-.094 1.146 1.146 0 0 0-.567-.129c-.593 0-1.382.297-2.007.797l-1.961 1.156c-1.016.426-1.848 1.293-1.848 1.93 0 .64-.898 1.16-1.996 1.16H13.14c-1.102 0-2-.515-2-1.14 0-.63-.832-1.477-1.852-1.887l-2.047-1.16c-.637-.512-1.426-.813-2.008-.813-.199 0-.379.035-.515.114a.648.648 0 0 1-.332.085c-.52 0-1.18-.5-1.621-1.273l-.59-1.031c-.543-.953-.555-1.98-.024-2.285.532-.305.782-1.434.551-2.504V14.8c0-1.09.02-1.18.02-1.18.238-1.074-.008-2.203-.551-2.516-.54-.304-.54-1.34.008-2.293l.59-1.03c.437-.766 1.101-1.255 1.636-1.255a.73.73 0 0 1 .364.094c.152.086.343.125.566.125.594 0 1.379-.297 2.004-.793l1.945-1.066c1.02-.407 1.856-1.278 1.856-1.934 0-.656.898-1.191 2-1.191h1.156c1.098 0 1.996.543 1.996 1.21 0 .669.832 1.555 1.848 1.973L20 6.012c.617.492 1.402.777 2.012.777.242 0 .453-.047.62-.14a.79.79 0 0 1 .403-.102c.55 0 1.223.476 1.652 1.23l.59 1.032c.543.953.52 2.004-.062 2.336-.574.332-.86 1.48-.625 2.554 0 0 .008.04.008 1.102v1.011c-.215 1.051.07 2.176.636 2.5.567.325.586 1.368.04 2.325Zm0 0"/><path d="M13.61 7.61a7.084 7.084 0 0 0-7.083 7.085 7.085 7.085 0 1 0 14.168 0A7.088 7.088 0 0 0 13.61 7.61Zm0 12.41a5.33 5.33 0 0 1-5.325-5.325 5.33 5.33 0 0 1 5.324-5.32 5.327 5.327 0 0 1 5.325 5.32 5.328 5.328 0 0 1-5.325 5.325Zm0 0"/><path d="M13.684 9.906a4.722 4.722 0 0 0-4.72 4.719 4.722 4.722 0 0 0 4.72 4.719 4.724 4.724 0 0 0 4.714-4.719 4.724 4.724 0 0 0-4.714-4.719Zm0 7.676a2.954 2.954 0 1 1 0-5.91 2.953 2.953 0 0 1 2.953 2.953 2.957 2.957 0 0 1-2.953 2.957Zm0 0"/></svg>
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index 5adc0d2a40e41bf2944e0aa079c169decf4fb253..7c5c6eb3d2bbf1b5ee5b713763a09d05749240cc 100644 (file)
@@ -222,7 +222,7 @@ fn mod_item_in(&mut self, _item: &clean::Item) -> Result<(), Error> {
     fn after_krate(&mut self) -> Result<(), Error> {
         debug!("Done with crate");
 
-        debug!("Adding Primitve impls");
+        debug!("Adding Primitive impls");
         for primitive in Rc::clone(&self.cache).primitive_locations.values() {
             self.get_impls(*primitive);
         }
index 09dd92564d39a42de2a79a140ec36b9b738d978e..80b8d67401ad143086b69363c11e86e51f1dae2b 100644 (file)
@@ -1,5 +1,4 @@
 //@ignore-target-windows: No libc on Windows
-#![feature(cstr_from_bytes_until_nul)]
 use std::ffi::{CStr, CString};
 use std::thread;
 
index 4f07fca82d1ebfb860461506cf7ba25986b0d7a2..706db892cb30d528759fcf9de517b68a2627e429 100644 (file)
@@ -77,7 +77,6 @@
     -Z                            llvm-plugins=val -- a list LLVM plugins to enable (space separated)
     -Z                         llvm-time-trace=val -- generate JSON tracing data file from LLVM data (default: no)
     -Z                         location-detail=val -- what location details should be tracked when using caller_location, either `none`, or a comma separated list of location details, for which valid options are `file`, `line`, and `column` (default: `file,line,column`)
-    -Z                           log-backtrace=val -- add a backtrace along with logging
     -Z                                      ls=val -- list the symbols defined by a library crate (default: no)
     -Z                         macro-backtrace=val -- show macro backtraces (default: no)
     -Z             maximal-hir-to-mir-coverage=val -- save as much information as possible about the correspondence between MIR and HIR as source scopes (default: no)
index 3979d2001fc5957ae109d6e4bdd9f8b672a6b8b9..e42edf1d4af51ad13062ae292a9ed19a510401b1 100644 (file)
@@ -1,9 +1,9 @@
 // run-pass
 //
-// This test makes sure that log-backtrace option doesn't give a compilation error.
+// This test makes sure that log-backtrace option at least parses correctly
 //
 // dont-check-compiler-stdout
 // dont-check-compiler-stderr
 // rustc-env:RUSTC_LOG=info
-// compile-flags: -Zlog-backtrace=rustc_metadata::creader
+// rustc-env:RUSTC_LOG_BACKTRACE=rustc_metadata::creader
 fn main() {}
index afa91da133dc0f0b862211777c837d3bb4564741..58be4519720178b8fab1f5504fc43607bc8e05a9 100644 (file)
@@ -33,4 +33,14 @@ struct FlexZeroSlice {
     //~^^ this was previously accepted
 }
 
+// Again, currently allowed, but will be phased out.
+#[derive(Debug)]
+#[repr(packed)]
+struct WithStr {
+    width: u8,
+    data: str,
+    //~^ WARNING string slice in a packed struct that derives a built-in trait
+    //~^^ this was previously accepted
+}
+
 fn main() {}
index 7ed84af91bdc354d4a3eb14e6633c4f9e8040d1b..0cfe03869af1bd6846e3e836dca9d12ee5f37fd0 100644 (file)
@@ -13,6 +13,20 @@ LL |     data: [u8],
    = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+warning: string slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-with-repr-packed.rs:41:5
+   |
+LL | #[derive(Debug)]
+   |          ----- in this derive macro expansion
+...
+LL |     data: str,
+   |     ^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
+
 error[E0507]: cannot move out of `self` which is behind a shared reference
   --> $DIR/deriving-with-repr-packed.rs:22:10
    |
@@ -24,7 +38,7 @@ LL | struct X(Y);
    |
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to previous error; 1 warning emitted
+error: aborting due to previous error; 2 warnings emitted
 
 For more information about this error, try `rustc --explain E0507`.
 Future incompatibility report: Future breakage diagnostic:
@@ -43,3 +57,19 @@ LL |     data: [u8],
    = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
+Future breakage diagnostic:
+warning: string slice in a packed struct that derives a built-in trait
+  --> $DIR/deriving-with-repr-packed.rs:41:5
+   |
+LL | #[derive(Debug)]
+   |          ----- in this derive macro expansion
+...
+LL |     data: str,
+   |     ^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #107457 <https://github.com/rust-lang/rust/issues/107457>
+   = help: consider implementing the trait by hand, or remove the `packed` attribute
+   = note: `#[warn(byte_slice_in_packed_struct_with_derive)]` on by default
+   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
+
index 5cd217df6fc2ff91c814e5c6abb980571141b802..fdc2a7666d69b0a6ccbaad809fd933bf45124919 100644 (file)
@@ -626,7 +626,7 @@ impl<T> const Trait for T {}
         stringify_item!(
             impl ~const Struct {}
         ),
-        "impl Struct {}", // FIXME
+        "impl ~const Struct {}",
     );
 
     // ItemKind::MacCall
@@ -838,7 +838,7 @@ fn test_ty() {
     assert_eq!(stringify_ty!(dyn Send + 'a), "dyn Send + 'a");
     assert_eq!(stringify_ty!(dyn 'a + Send), "dyn 'a + Send");
     assert_eq!(stringify_ty!(dyn ?Sized), "dyn ?Sized");
-    assert_eq!(stringify_ty!(dyn ~const Clone), "dyn Clone"); // FIXME
+    assert_eq!(stringify_ty!(dyn ~const Clone), "dyn ~const Clone");
     assert_eq!(stringify_ty!(dyn for<'a> Send), "dyn for<'a> Send");
 
     // TyKind::ImplTrait
@@ -846,7 +846,7 @@ fn test_ty() {
     assert_eq!(stringify_ty!(impl Send + 'a), "impl Send + 'a");
     assert_eq!(stringify_ty!(impl 'a + Send), "impl 'a + Send");
     assert_eq!(stringify_ty!(impl ?Sized), "impl ?Sized");
-    assert_eq!(stringify_ty!(impl ~const Clone), "impl Clone"); // FIXME
+    assert_eq!(stringify_ty!(impl ~const Clone), "impl ~const Clone");
     assert_eq!(stringify_ty!(impl for<'a> Send), "impl for<'a> Send");
 
     // TyKind::Paren
diff --git a/tests/ui/parser/bad-recover-kw-after-impl.rs b/tests/ui/parser/bad-recover-kw-after-impl.rs
new file mode 100644 (file)
index 0000000..218cd76
--- /dev/null
@@ -0,0 +1,15 @@
+// check-pass
+
+// edition:2021
+// for the `impl` + keyword test
+
+macro_rules! impl_primitive {
+    ($ty:ty) => {
+        compile_error!("whoops");
+    };
+    (impl async) => {};
+}
+
+impl_primitive!(impl async);
+
+fn main() {}
diff --git a/tests/ui/parser/bad-recover-ty-after-impl.rs b/tests/ui/parser/bad-recover-ty-after-impl.rs
new file mode 100644 (file)
index 0000000..510e08b
--- /dev/null
@@ -0,0 +1,17 @@
+// check-pass
+
+macro_rules! impl_primitive {
+    ($ty:ty) => { impl_primitive!(impl $ty); };
+    (impl $ty:ty) => { fn a(_: $ty) {} }
+}
+
+impl_primitive! { u8 }
+
+macro_rules! test {
+    ($ty:ty) => { compile_error!("oh no"); };
+    (impl &) => {};
+}
+
+test!(impl &);
+
+fn main() {}
diff --git a/tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs b/tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs
new file mode 100644 (file)
index 0000000..72edfbc
--- /dev/null
@@ -0,0 +1,13 @@
+// check-pass
+
+#![feature(derive_const)]
+#![feature(const_trait_impl)]
+
+#[derive_const(PartialEq)]
+pub struct Reverse<T>(T);
+
+const fn foo(a: Reverse<i32>, b: Reverse<i32>) -> bool {
+    a == b
+}
+
+fn main() {}
diff --git a/tests/ui/traits/new-solver/provisional-result-done.rs b/tests/ui/traits/new-solver/provisional-result-done.rs
new file mode 100644 (file)
index 0000000..a3d9792
--- /dev/null
@@ -0,0 +1,37 @@
+// known-bug: unknown
+// compile-flags: -Ztrait-solver=next
+// failure-status: 101
+// normalize-stderr-test "note: .*\n\n" -> ""
+// normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
+// rustc-env:RUST_BACKTRACE=0
+
+// This tests checks that we update results in the provisional cache when
+// we pop a goal from the stack.
+#![feature(auto_traits)]
+auto trait Coinductive {}
+struct Foo<T>(T);
+struct Bar<T>(T);
+
+impl<T> Coinductive for Foo<T>
+where
+    Bar<T>: Coinductive
+{}
+
+impl<T> Coinductive for Bar<T>
+where
+    Foo<T>: Coinductive,
+    Bar<T>: ConstrainInfer,
+{}
+
+trait ConstrainInfer {}
+impl ConstrainInfer for Bar<u8> {}
+impl ConstrainInfer for Foo<u16> {}
+
+fn impls<T: Coinductive>() -> T { todo!() }
+
+fn constrain<T: ConstrainInfer>(_: T) {}
+
+fn main() {
+    // This should constrain `_` to `u8`.
+    impls::<Foo<_>>();
+}
diff --git a/tests/ui/traits/new-solver/provisional-result-done.stderr b/tests/ui/traits/new-solver/provisional-result-done.stderr
new file mode 100644 (file)
index 0000000..ffc92b8
--- /dev/null
@@ -0,0 +1,6 @@
+error: the compiler unexpectedly panicked. this is a bug.
+
+query stack during panic:
+#0 [check_well_formed] checking that `<impl at $DIR/provisional-result-done.rs:20:1: 20:31>` is well-formed
+#1 [check_mod_type_wf] checking that types are well-formed in top-level module
+end of query stack
diff --git a/tests/ui/unpretty/ast-const-trait-bound.rs b/tests/ui/unpretty/ast-const-trait-bound.rs
new file mode 100644 (file)
index 0000000..dbcba78
--- /dev/null
@@ -0,0 +1,4 @@
+// compile-flags: -Zunpretty=normal
+// check-pass
+
+fn foo() where T: ~const Bar {}
diff --git a/tests/ui/unpretty/ast-const-trait-bound.stdout b/tests/ui/unpretty/ast-const-trait-bound.stdout
new file mode 100644 (file)
index 0000000..dbcba78
--- /dev/null
@@ -0,0 +1,4 @@
+// compile-flags: -Zunpretty=normal
+// check-pass
+
+fn foo() where T: ~const Bar {}