reduce false positives of tail-expr-drop-order from consumed values

rust-lang · dingxiangfei2009 · Sep 1, 2024 · Sep 22, 2024 · Sep 22, 2024 · Sep 23, 2024
commit 081c77fdf02a5c5f0befcae2d46c7b71d8b67080
diff --git a/Cargo.lock b/Cargo.lock
@@ -4090,6 +4090,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_infer",
+ "rustc_lint",
  "rustc_macros",
  "rustc_middle",
  "rustc_mir_build",

diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
@@ -690,7 +690,7 @@ impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R>
             TerminatorKind::SwitchInt { discr, targets: _ } => {
                 self.consume_operand(loc, (discr, span), state);
             }
-            TerminatorKind::Drop { place, target: _, unwind: _, replace } => {
+            TerminatorKind::Drop { place, target: _, scope: _, unwind: _, replace } => {
                 debug!(
                     "visit_terminator_drop \
                      loc: {:?} term: {:?} place: {:?} span: {:?}",

diff --git a/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs b/compiler/rustc_borrowck/src/polonius/loan_invalidations.rs
@@ -103,7 +103,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'a, 'tcx> {
             TerminatorKind::SwitchInt { discr, targets: _ } => {
                 self.consume_operand(location, discr);
             }
-            TerminatorKind::Drop { place: drop_place, target: _, unwind: _, replace } => {
+            TerminatorKind::Drop { place: drop_place, target: _, scope: _, unwind: _, replace } => {
                 let write_kind =
                     if *replace { WriteKind::Replace } else { WriteKind::StorageDeadOrDrop };
                 self.access_place(

diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -549,7 +549,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
             | TerminatorKind::CoroutineDrop => {
                 bug!("shouldn't exist at codegen {:?}", bb_data.terminator());
             }
-            TerminatorKind::Drop { place, target, unwind: _, replace: _ } => {
+            TerminatorKind::Drop { place, target, unwind: _, scope: _, replace: _ } => {
                 let drop_place = codegen_place(fx, *place);
                 crate::abi::codegen_drop(fx, source_info, drop_place, *target);
             }

diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -1322,7 +1322,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 MergingSucc::False
             }
 
-            mir::TerminatorKind::Drop { place, target, unwind, replace: _ } => self
+            mir::TerminatorKind::Drop { place, target, unwind, scope: _, replace: _ } => self
                 .codegen_drop_terminator(
                     helper,
                     bx,

diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -528,7 +528,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 }
             }
 
-            Drop { place, target, unwind, replace: _ } => {
+            Drop { place, target, unwind, scope: _, replace: _ } => {
                 let place = self.eval_place(place)?;
                 let instance = Instance::resolve_drop_in_place(*self.tcx, place.layout.ty);
                 if let ty::InstanceKind::DropGlue(_, None) = instance.def {

diff --git a/compiler/rustc_hir_typeck/src/expr_use_visitor.rs b/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
@@ -150,6 +150,50 @@ pub trait TypeInformationCtxt<'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx>;
 }
 
+impl<'tcx> TypeInformationCtxt<'tcx> for (TyCtxt<'tcx>, LocalDefId) {
+    type TypeckResults<'a> = &'tcx ty::TypeckResults<'tcx>
+    where
+        Self: 'a;
+
+    type Error = !;
+
+    fn typeck_results(&self) -> Self::TypeckResults<'_> {
+        self.0.typeck(self.1)
+    }
+
+    fn resolve_vars_if_possible<T: TypeFoldable<TyCtxt<'tcx>>>(&self, t: T) -> T {
+        t
+    }
+
+    fn try_structurally_resolve_type(&self, _span: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
+        ty
+    }
+
+    fn report_error(&self, span: Span, msg: impl ToString) -> Self::Error {
+        span_bug!(span, "{}", msg.to_string())
+    }
+
+    fn error_reported_in_ty(&self, _ty: Ty<'tcx>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    fn tainted_by_errors(&self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    fn type_is_copy_modulo_regions(&self, ty: Ty<'tcx>) -> bool {
+        ty.is_copy_modulo_regions(self.0, self.0.param_env(self.1))
+    }
+
+    fn body_owner_def_id(&self) -> LocalDefId {
+        self.1
+    }
+
+    fn tcx(&self) -> TyCtxt<'tcx> {
+        self.0
+    }
+}
+
 impl<'tcx> TypeInformationCtxt<'tcx> for &FnCtxt<'_, 'tcx> {
     type TypeckResults<'a>
         = Ref<'a, ty::TypeckResults<'tcx>>

diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
@@ -789,9 +789,6 @@ lint_suspicious_double_ref_clone =
 lint_suspicious_double_ref_deref =
     using `.deref()` on a double reference, which returns `{$ty}` instead of dereferencing the inner type
 
-lint_tail_expr_drop_order = these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
-    .label = these values have significant drop implementation and will observe changes in drop order under Edition 2024
-
 lint_trailing_semi_macro = trailing semicolon in macro used in expression position
     .note1 = macro invocations at the end of a block are treated as expressions
     .note2 = to ignore the value produced by the macro, add a semicolon after the invocation of `{$name}`

diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
@@ -82,7 +82,6 @@ mod redundant_semicolon;
 mod reference_casting;
 mod shadowed_into_iter;
 mod static_mut_refs;
-mod tail_expr_drop_order;
 mod traits;
 mod types;
 mod unit_bindings;
@@ -123,7 +122,6 @@ use rustc_middle::ty::TyCtxt;
 use shadowed_into_iter::ShadowedIntoIter;
 pub use shadowed_into_iter::{ARRAY_INTO_ITER, BOXED_SLICE_INTO_ITER};
 use static_mut_refs::*;
-use tail_expr_drop_order::TailExprDropOrder;
 use traits::*;
 use types::*;
 use unit_bindings::*;
@@ -248,7 +246,6 @@ late_lint_methods!(
             AsyncFnInTrait: AsyncFnInTrait,
             NonLocalDefinitions: NonLocalDefinitions::default(),
             ImplTraitOvercaptures: ImplTraitOvercaptures,
-            TailExprDropOrder: TailExprDropOrder,
             IfLetRescope: IfLetRescope::default(),
             StaticMutRefs: StaticMutRefs,
             UnqualifiedLocalImports: UnqualifiedLocalImports,