diff options
| -rw-r--r-- | compiler/rustc_monomorphize/src/collector.rs | 141 |
1 files changed, 83 insertions, 58 deletions
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 8525a4e74c2..6ea177bb6ea 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -432,7 +432,7 @@ fn collect_items_rec<'tcx>( hir::InlineAsmOperand::SymFn { anon_const } => { let fn_ty = tcx.typeck_body(anon_const.body).node_type(anon_const.hir_id); - visit_fn_use(tcx, fn_ty, false, *op_sp, &mut used_items, &[]); + visit_fn_use(tcx, fn_ty, false, *op_sp, &mut used_items); } hir::InlineAsmOperand::SymStatic { path: _, def_id } => { let instance = Instance::mono(tcx, *def_id); @@ -593,11 +593,9 @@ struct MirUsedCollector<'a, 'tcx> { instance: Instance<'tcx>, /// Spans for move size lints already emitted. Helps avoid duplicate lints. move_size_spans: Vec<Span>, - /// If true, we should temporarily skip move size checks, because we are - /// processing an operand to a `skip_move_check_fns` function call. - skip_move_size_check: bool, + visiting_call_terminator: bool, /// Set of functions for which it is OK to move large data into. - skip_move_check_fns: Vec<DefId>, + skip_move_check_fns: Option<Vec<DefId>>, } impl<'a, 'tcx> MirUsedCollector<'a, 'tcx> { @@ -613,7 +611,20 @@ impl<'a, 'tcx> MirUsedCollector<'a, 'tcx> { ) } - fn check_move_size(&mut self, limit: usize, operand: &mir::Operand<'tcx>, location: Location) { + fn check_operand_move_size(&mut self, operand: &mir::Operand<'tcx>, location: Location) { + let limit = self.tcx.move_size_limit().0; + if limit == 0 { + return; + } + + // This function is called by visit_operand() which visits _all_ + // operands, including TerminatorKind::Call operands. But if + // check_fn_args_move_size() has been called, the operands have already + // been visited. Do not visit them again. + if self.visiting_call_terminator { + return; + } + let limit = Size::from_bytes(limit); let ty = operand.ty(self.body, self.tcx); let ty = self.monomorphize(ty); @@ -651,6 +662,38 @@ impl<'a, 'tcx> MirUsedCollector<'a, 'tcx> { ); self.move_size_spans.push(source_info.span); } + + fn check_fn_args_move_size( + &mut self, + callee_ty: Ty<'tcx>, + args: &[mir::Operand<'tcx>], + location: Location, + ) { + let limit = self.tcx.move_size_limit(); + if limit.0 == 0 { + return; + } + + if args.is_empty() { + return; + } + + // Allow large moves into container types that themselves are cheap to move + let ty::FnDef(def_id, _) = *callee_ty.kind() else { + return; + }; + if self + .skip_move_check_fns + .get_or_insert_with(|| build_skip_move_check_fns(self.tcx)) + .contains(&def_id) + { + return; + } + + for arg in args { + self.check_operand_move_size(arg, location); + } + } } impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { @@ -696,14 +739,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { ) => { let fn_ty = operand.ty(self.body, self.tcx); let fn_ty = self.monomorphize(fn_ty); - visit_fn_use( - self.tcx, - fn_ty, - false, - span, - &mut self.output, - &self.skip_move_check_fns, - ); + visit_fn_use(self.tcx, fn_ty, false, span, &mut self.output); } mir::Rvalue::Cast( mir::CastKind::PointerCoercion(PointerCoercion::ClosureFnPointer(_)), @@ -775,17 +811,11 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { }; match terminator.kind { - mir::TerminatorKind::Call { ref func, .. } => { + mir::TerminatorKind::Call { ref func, ref args, .. } => { let callee_ty = func.ty(self.body, tcx); let callee_ty = self.monomorphize(callee_ty); - self.skip_move_size_check = visit_fn_use( - self.tcx, - callee_ty, - true, - source, - &mut self.output, - &self.skip_move_check_fns, - ) + self.check_fn_args_move_size(callee_ty, args, location); + visit_fn_use(self.tcx, callee_ty, true, source, &mut self.output) } mir::TerminatorKind::Drop { ref place, .. } => { let ty = place.ty(self.body, self.tcx).ty; @@ -797,7 +827,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { match *op { mir::InlineAsmOperand::SymFn { ref value } => { let fn_ty = self.monomorphize(value.const_.ty()); - visit_fn_use(self.tcx, fn_ty, false, source, &mut self.output, &[]); + visit_fn_use(self.tcx, fn_ty, false, source, &mut self.output); } mir::InlineAsmOperand::SymStatic { def_id } => { let instance = Instance::mono(self.tcx, def_id); @@ -835,16 +865,14 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirUsedCollector<'a, 'tcx> { push_mono_lang_item(self, reason.lang_item()); } + self.visiting_call_terminator = matches!(terminator.kind, mir::TerminatorKind::Call { .. }); self.super_terminator(terminator, location); - self.skip_move_size_check = false; + self.visiting_call_terminator = false; } fn visit_operand(&mut self, operand: &mir::Operand<'tcx>, location: Location) { self.super_operand(operand, location); - let move_size_limit = self.tcx.move_size_limit().0; - if move_size_limit > 0 && !self.skip_move_size_check { - self.check_move_size(move_size_limit, operand, location); - } + self.check_operand_move_size(operand, location); } fn visit_local( @@ -873,11 +901,8 @@ fn visit_fn_use<'tcx>( is_direct_call: bool, source: Span, output: &mut MonoItems<'tcx>, - skip_move_check_fns: &[DefId], -) -> bool { - let mut skip_move_size_check = false; +) { if let ty::FnDef(def_id, args) = *ty.kind() { - skip_move_size_check = skip_move_check_fns.contains(&def_id); let instance = if is_direct_call { ty::Instance::expect_resolve(tcx, ty::ParamEnv::reveal_all(), def_id, args) } else { @@ -888,7 +913,6 @@ fn visit_fn_use<'tcx>( }; visit_instance_use(tcx, instance, is_direct_call, source, output); } - skip_move_size_check } fn visit_instance_use<'tcx>( @@ -1395,6 +1419,29 @@ fn assoc_fn_of_type<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, fn_ident: Ident) -> return None; } +fn build_skip_move_check_fns(tcx: TyCtxt<'_>) -> Vec<DefId> { + let mut skip_move_check_fns = vec![]; + add_assoc_fn( + tcx, + tcx.lang_items().owned_box(), + Ident::from_str("new"), + &mut skip_move_check_fns, + ); + add_assoc_fn( + tcx, + tcx.get_diagnostic_item(sym::Arc), + Ident::from_str("new"), + &mut skip_move_check_fns, + ); + add_assoc_fn( + tcx, + tcx.get_diagnostic_item(sym::Rc), + Ident::from_str("new"), + &mut skip_move_check_fns, + ); + skip_move_check_fns +} + /// Scans the MIR in order to find function calls, closures, and drop-glue. #[instrument(skip(tcx, output), level = "debug")] fn collect_used_items<'tcx>( @@ -1404,28 +1451,6 @@ fn collect_used_items<'tcx>( ) { let body = tcx.instance_mir(instance.def); - let mut skip_move_check_fns = vec![]; - if tcx.move_size_limit().0 > 0 { - add_assoc_fn( - tcx, - tcx.lang_items().owned_box(), - Ident::from_str("new"), - &mut skip_move_check_fns, - ); - add_assoc_fn( - tcx, - tcx.get_diagnostic_item(sym::Arc), - Ident::from_str("new"), - &mut skip_move_check_fns, - ); - add_assoc_fn( - tcx, - tcx.get_diagnostic_item(sym::Rc), - Ident::from_str("new"), - &mut skip_move_check_fns, - ); - } - // Here we rely on the visitor also visiting `required_consts`, so that we evaluate them // and abort compilation if any of them errors. MirUsedCollector { @@ -1434,8 +1459,8 @@ fn collect_used_items<'tcx>( output, instance, move_size_spans: vec![], - skip_move_size_check: false, - skip_move_check_fns, + visiting_call_terminator: false, + skip_move_check_fns: None, } .visit_body(&body); } |