Auto merge of #104455 - the8472:dont-drain-on-drop, r=Amanieu

Don't drain-on-drop in DrainFilter impls of various collections.

This removes drain-on-drop behavior from various unstable DrainFilter impls (not yet for HashSet/Map) because that behavior [is problematic](https://github.com/rust-lang/rust/issues/43244#issuecomment-641638196) (because it can lead to panic-in-drop when user closures panic) and may become forbidden if [this draft RFC passes](https://github.com/rust-lang/rfcs/pull/3288).

closes #101122

[ACP](https://github.com/rust-lang/libs-team/issues/136)

affected tracking issues
* #43244
* #70530
* #59618

Related hashbrown update: https://github.com/rust-lang/hashbrown/pull/374

17 files changed, 24 insertions, 32 deletions

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 7a297ea0d5f..24d1cc8af82 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -4,7 +4,7 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(array_windows)]
-#![feature(drain_filter)]
+#![feature(extract_if)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(never_type)]
@@ -1399,7 +1399,7 @@ impl HandlerInner {
                     !self.emitted_diagnostics.insert(diagnostic_hash)
                 };
 
-                diagnostic.children.drain_filter(already_emitted_sub).for_each(|_| {});
+                diagnostic.children.extract_if(already_emitted_sub).for_each(|_| {});
 
                 self.emitter.emit_diagnostic(diagnostic);
                 if diagnostic.is_error() {
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 5cd2cd50c11..d2a1b1c1a42 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -59,8 +59,6 @@ This API is completely unstable and subject to change.
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
-#![feature(drain_filter)]
-#![feature(hash_drain_filter)]
 #![feature(if_let_guard)]
 #![feature(is_sorted)]
 #![feature(iter_intersperse)]
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 4a3e28ffce9..bf8ad5faac4 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -753,20 +753,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return;
         }
 
-        errors.drain_filter(|error| {
+        errors.retain(|error| {
             let Error::Invalid(
                 provided_idx,
                 expected_idx,
                 Compatibility::Incompatible(Some(e)),
-            ) = error else { return false };
+            ) = error else { return true };
             let (provided_ty, provided_span) = provided_arg_tys[*provided_idx];
             let trace =
                 mk_trace(provided_span, formal_and_expected_inputs[*expected_idx], provided_ty);
             if !matches!(trace.cause.as_failure_code(*e), FailureCode::Error0308) {
                 self.err_ctxt().report_and_explain_type_error(trace, *e).emit();
-                return true;
+                return false;
             }
-            false
+            true
         });
 
         // We're done if we found errors, but we already emitted them.
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index b97b55d8f7e..7a897778ff7 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -5,7 +5,6 @@
 #![feature(box_patterns)]
 #![feature(min_specialization)]
 #![feature(control_flow_enum)]
-#![feature(drain_filter)]
 #![feature(option_as_slice)]
 #![allow(rustc::potential_query_instability)]
 #![recursion_limit = "256"]
diff --git a/compiler/rustc_metadata/src/lib.rs b/compiler/rustc_metadata/src/lib.rs
index 9f664d0f0c8..87373d99743 100644
--- a/compiler/rustc_metadata/src/lib.rs
+++ b/compiler/rustc_metadata/src/lib.rs
@@ -1,6 +1,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(decl_macro)]
-#![feature(drain_filter)]
+#![feature(extract_if)]
 #![feature(generators)]
 #![feature(iter_from_generator)]
 #![feature(let_chains)]
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index c83c47e722b..0dd7b119791 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -425,7 +425,7 @@ impl<'tcx> Collector<'tcx> {
             // can move them to the end of the list below.
             let mut existing = self
                 .libs
-                .drain_filter(|lib| {
+                .extract_if(|lib| {
                     if lib.name.as_str() == passed_lib.name {
                         // FIXME: This whole logic is questionable, whether modifiers are
                         // involved or not, library reordering and kind overriding without
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index 0d6c2eba06c..1b125e8e26d 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -54,7 +54,7 @@
 #![feature(try_reserve_kind)]
 #![feature(nonzero_ops)]
 #![feature(decl_macro)]
-#![feature(drain_filter)]
+#![feature(extract_if)]
 #![feature(intra_doc_pointers)]
 #![feature(yeet_expr)]
 #![feature(result_option_inspect)]
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index 9c91b778403..9c948dba1e4 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -237,7 +237,7 @@ pub fn suggest_constraining_type_params<'a>(
 
         {
             let mut sized_constraints =
-                constraints.drain_filter(|(_, def_id)| *def_id == tcx.lang_items().sized_trait());
+                constraints.extract_if(|(_, def_id)| *def_id == tcx.lang_items().sized_trait());
             if let Some((constraint, def_id)) = sized_constraints.next() {
                 applicability = Applicability::MaybeIncorrect;
 
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 7d9f6c38e36..9c8c0ea0be0 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -2,7 +2,6 @@
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![feature(box_patterns)]
-#![feature(drain_filter)]
 #![feature(is_sorted)]
 #![feature(let_chains)]
 #![feature(map_try_insert)]
diff --git a/compiler/rustc_mir_transform/src/sroa.rs b/compiler/rustc_mir_transform/src/sroa.rs
index e4b3b8b9262..881a1547c52 100644
--- a/compiler/rustc_mir_transform/src/sroa.rs
+++ b/compiler/rustc_mir_transform/src/sroa.rs
@@ -436,13 +436,12 @@ impl<'tcx, 'll> MutVisitor<'tcx> for ReplacementVisitor<'tcx, 'll> {
             VarDebugInfoContents::Composite { ty: _, ref mut fragments } => {
                 let mut new_fragments = Vec::new();
                 debug!(?fragments);
-                fragments
-                    .drain_filter(|fragment| {
-                        if let Some(repl) =
+                fragments.retain_mut(|fragment| {
+                    if let Some(repl) =
                             self.replacements.replace_place(self.tcx, fragment.contents.as_ref())
                         {
                             fragment.contents = repl;
-                            false
+                            true
                         } else if let Some(local) = fragment.contents.as_local()
                             && let Some(frg) = self.gather_debug_info_fragments(local)
                         {
@@ -450,12 +449,11 @@ impl<'tcx, 'll> MutVisitor<'tcx> for ReplacementVisitor<'tcx, 'll> {
                                 f.projection.splice(0..0, fragment.projection.iter().copied());
                                 f
                             }));
-                            true
-                        } else {
                             false
+                        } else {
+                            true
                         }
-                    })
-                    .for_each(drop);
+                });
                 debug!(?fragments);
                 debug!(?new_fragments);
                 fragments.extend(new_fragments);
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index ca811c9ed7d..e42b2df1a5a 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -2494,7 +2494,7 @@ fn show_candidates(
     for path_strings in [&mut accessible_path_strings, &mut inaccessible_path_strings] {
         path_strings.sort_by(|a, b| a.0.cmp(&b.0));
         let core_path_strings =
-            path_strings.drain_filter(|p| p.0.starts_with("core::")).collect::<Vec<_>>();
+            path_strings.extract_if(|p| p.0.starts_with("core::")).collect::<Vec<_>>();
         path_strings.extend(core_path_strings);
         path_strings.dedup_by(|a, b| a.0 == b.0);
     }
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 2f9759a668b..e4b01ef2b17 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -496,7 +496,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
         // Try to filter out intrinsics candidates, as long as we have
         // some other candidates to suggest.
         let intrinsic_candidates: Vec<_> = candidates
-            .drain_filter(|sugg| {
+            .extract_if(|sugg| {
                 let path = path_names_to_string(&sugg.path);
                 path.starts_with("core::intrinsics::") || path.starts_with("std::intrinsics::")
             })
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index db97039b907..82b333fee28 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -9,7 +9,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(drain_filter)]
+#![feature(extract_if)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
index ed3994be987..56d37d58de7 100644
--- a/compiler/rustc_trait_selection/src/lib.rs
+++ b/compiler/rustc_trait_selection/src/lib.rs
@@ -14,8 +14,7 @@
 #![feature(associated_type_bounds)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
-#![feature(drain_filter)]
-#![feature(hash_drain_filter)]
+#![feature(extract_if)]
 #![feature(let_chains)]
 #![feature(if_let_guard)]
 #![feature(never_type)]
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index ab58684ffd9..db9cb82585f 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -354,7 +354,7 @@ pub fn normalize_param_env_or_error<'tcx>(
     // This works fairly well because trait matching does not actually care about param-env
     // TypeOutlives predicates - these are normally used by regionck.
     let outlives_predicates: Vec<_> = predicates
-        .drain_filter(|predicate| {
+        .extract_if(|predicate| {
             matches!(
                 predicate.kind().skip_binder(),
                 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 563cc257e03..0a1e971f268 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1170,11 +1170,11 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>(
             };
 
             let mut deduped: SsoHashSet<_> = Default::default();
-            result.obligations.drain_filter(|projected_obligation| {
+            result.obligations.retain(|projected_obligation| {
                 if !deduped.insert(projected_obligation.clone()) {
-                    return true;
+                    return false;
                 }
-                false
+                true
             });
 
             if use_cache {
diff --git a/compiler/rustc_traits/src/lib.rs b/compiler/rustc_traits/src/lib.rs
index 907e2d39c51..590d0bd0e42 100644
--- a/compiler/rustc_traits/src/lib.rs
+++ b/compiler/rustc_traits/src/lib.rs
@@ -4,7 +4,6 @@
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![feature(let_chains)]
-#![feature(drain_filter)]
 #![recursion_limit = "256"]
 
 #[macro_use]