diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/mod.rs | 15 | ||||
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_borrowck/src/lib.rs | 25 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/build/expr/stmt.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_mir_build/src/build/scope.rs | 32 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/elaborate_drops.rs | 19 | ||||
| -rw-r--r-- | compiler/rustc_span/src/hygiene.rs | 2 |
7 files changed, 80 insertions, 23 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index a99fd594a07..a1817f85483 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -925,7 +925,20 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { return OtherUse(use_span); } - for stmt in &self.body[location.block].statements[location.statement_index + 1..] { + // drop and replace might have moved the assignment to the next block + let maybe_additional_statement = + if let TerminatorKind::Drop { target: drop_target, .. } = + self.body[location.block].terminator().kind + { + self.body[drop_target].statements.first() + } else { + None + }; + + let statements = + self.body[location.block].statements[location.statement_index + 1..].iter(); + + for stmt in statements.chain(maybe_additional_statement) { if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind { let (&def_id, is_generator) = match kind { box AggregateKind::Closure(def_id, _) => (def_id, false), diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs index 328ac880dd4..eded913ae96 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs @@ -828,7 +828,13 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> { let Some(hir::Node::Item(item)) = node else { return; }; let hir::ItemKind::Fn(.., body_id) = item.kind else { return; }; let body = self.infcx.tcx.hir().body(body_id); - let mut v = V { assign_span: span, err, ty, suggested: false }; + let mut assign_span = span; + // Drop desugaring is done at MIR build so it's not in the HIR + if let Some(DesugaringKind::Replace) = span.desugaring_kind() { + assign_span.remove_mark(); + } + + let mut v = V { assign_span, err, ty, suggested: false }; v.visit_body(body); if !v.suggested { err.help(&format!( diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs index 0f591460e9d..11a746ffb0a 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -40,7 +40,7 @@ use rustc_middle::mir::{InlineAsmOperand, Terminator, TerminatorKind}; use rustc_middle::ty::query::Providers; use rustc_middle::ty::{self, CapturedPlace, ParamEnv, RegionVid, TyCtxt}; use rustc_session::lint::builtin::UNUSED_MUT; -use rustc_span::{Span, Symbol}; +use rustc_span::{DesugaringKind, Span, Symbol}; use either::Either; use smallvec::SmallVec; @@ -1184,13 +1184,22 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { this.report_conflicting_borrow(location, place_span, bk, borrow); this.buffer_error(err); } - WriteKind::StorageDeadOrDrop => this - .report_borrowed_value_does_not_live_long_enough( - location, - borrow, - place_span, - Some(kind), - ), + WriteKind::StorageDeadOrDrop => { + if let Some(DesugaringKind::Replace) = place_span.1.desugaring_kind() { + // If this is a drop triggered by a reassignment, it's more user friendly + // to report a problem with the explicit assignment than the implicit drop. + this.report_illegal_mutation_of_borrowed( + location, place_span, borrow, + ) + } else { + this.report_borrowed_value_does_not_live_long_enough( + location, + borrow, + place_span, + Some(kind), + ) + } + } WriteKind::Mutate => { this.report_illegal_mutation_of_borrowed(location, place_span, borrow) } diff --git a/compiler/rustc_mir_build/src/build/expr/stmt.rs b/compiler/rustc_mir_build/src/build/expr/stmt.rs index 78083685193..ea5aeb67d85 100644 --- a/compiler/rustc_mir_build/src/build/expr/stmt.rs +++ b/compiler/rustc_mir_build/src/build/expr/stmt.rs @@ -40,7 +40,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // Generate better code for things that don't need to be // dropped. if lhs.ty.needs_drop(this.tcx, this.param_env) { - let rhs = unpack!(block = this.as_local_operand(block, rhs)); + let rhs = unpack!(block = this.as_local_rvalue(block, rhs)); let lhs = unpack!(block = this.as_place(block, lhs)); unpack!(block = this.build_drop_and_replace(block, lhs_span, lhs, rhs)); } else { diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs index 591b416337b..770701b3750 100644 --- a/compiler/rustc_mir_build/src/build/scope.rs +++ b/compiler/rustc_mir_build/src/build/scope.rs @@ -91,7 +91,7 @@ use rustc_middle::middle::region; use rustc_middle::mir::*; use rustc_middle::thir::{Expr, LintLevel}; -use rustc_span::{Span, DUMMY_SP}; +use rustc_span::{DesugaringKind, Span, DUMMY_SP}; #[derive(Debug)] pub struct Scopes<'tcx> { @@ -1118,24 +1118,35 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } /// Utility function for *non*-scope code to build their own drops + /// Force a drop at this point in the MIR by creating a new block. pub(crate) fn build_drop_and_replace( &mut self, block: BasicBlock, span: Span, place: Place<'tcx>, - value: Operand<'tcx>, + value: Rvalue<'tcx>, ) -> BlockAnd<()> { + let span = self.tcx.with_stable_hashing_context(|hcx| { + span.mark_with_reason(None, DesugaringKind::Replace, self.tcx.sess.edition(), hcx) + }); let source_info = self.source_info(span); - let next_target = self.cfg.start_new_block(); + + // create the new block for the assignment + let assign = self.cfg.start_new_block(); + self.cfg.push_assign(assign, source_info, place, value.clone()); + + // create the new block for the assignment in the case of unwinding + let assign_unwind = self.cfg.start_new_cleanup_block(); + self.cfg.push_assign(assign_unwind, source_info, place, value.clone()); self.cfg.terminate( block, source_info, - TerminatorKind::DropAndReplace { place, value, target: next_target, unwind: None }, + TerminatorKind::Drop { place, target: assign, unwind: Some(assign_unwind) }, ); self.diverge_from(block); - next_target.unit() + assign.unit() } /// Creates an `Assert` terminator and return the success block. @@ -1413,8 +1424,15 @@ impl<'tcx> DropTreeBuilder<'tcx> for Unwind { fn add_entry(cfg: &mut CFG<'tcx>, from: BasicBlock, to: BasicBlock) { let term = &mut cfg.block_data_mut(from).terminator_mut(); match &mut term.kind { - TerminatorKind::Drop { unwind, .. } - | TerminatorKind::DropAndReplace { unwind, .. } + TerminatorKind::Drop { unwind, .. } => { + if let Some(unwind) = *unwind { + let source_info = term.source_info; + cfg.terminate(unwind, source_info, TerminatorKind::Goto { target: to }); + } else { + *unwind = Some(to); + } + } + TerminatorKind::DropAndReplace { unwind, .. } | TerminatorKind::FalseUnwind { unwind, .. } | TerminatorKind::Call { cleanup: unwind, .. } | TerminatorKind::Assert { cleanup: unwind, .. } diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs index bdfd8dc6e99..29424f09695 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drops.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs @@ -14,7 +14,7 @@ use rustc_mir_dataflow::un_derefer::UnDerefer; use rustc_mir_dataflow::MoveDataParamEnv; use rustc_mir_dataflow::{on_all_children_bits, on_all_drop_children_bits}; use rustc_mir_dataflow::{Analysis, ResultsCursor}; -use rustc_span::Span; +use rustc_span::{DesugaringKind, Span}; use rustc_target::abi::VariantIdx; use std::fmt; @@ -425,10 +425,19 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { bb, ), LookupResult::Parent(..) => { - self.tcx.sess.delay_span_bug( - terminator.source_info.span, - &format!("drop of untracked value {:?}", bb), - ); + if !matches!( + terminator.source_info.span.desugaring_kind(), + Some(DesugaringKind::Replace), + ) { + self.tcx.sess.delay_span_bug( + terminator.source_info.span, + &format!("drop of untracked value {:?}", bb), + ); + } + // A drop and replace behind a pointer/array/whatever. + // The borrow checker requires that these locations are initialized before the assignment, + // so we just leave an unconditional drop. + assert!(!data.is_cleanup); } } } diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs index dee823eefde..9f22e9776d4 100644 --- a/compiler/rustc_span/src/hygiene.rs +++ b/compiler/rustc_span/src/hygiene.rs @@ -1151,6 +1151,7 @@ pub enum DesugaringKind { Await, ForLoop, WhileLoop, + Replace, } impl DesugaringKind { @@ -1166,6 +1167,7 @@ impl DesugaringKind { DesugaringKind::OpaqueTy => "`impl Trait`", DesugaringKind::ForLoop => "`for` loop", DesugaringKind::WhileLoop => "`while` loop", + DesugaringKind::Replace => "drop and replace", } } } |