diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
| -rw-r--r-- | compiler/rustc_mir_transform/src/inline.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/validate.rs | 1406 |
3 files changed, 1408 insertions, 2 deletions
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 401056cd496..fe2237dd2e9 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -1,7 +1,6 @@ //! Inlining pass for MIR functions use crate::deref_separator::deref_finder; use rustc_attr::InlineAttr; -use rustc_const_eval::transform::validate::validate_types; use rustc_hir::def::DefKind; use rustc_hir::def_id::DefId; use rustc_index::bit_set::BitSet; @@ -21,6 +20,7 @@ use rustc_target::spec::abi::Abi; use crate::cost_checker::CostChecker; use crate::simplify::simplify_cfg; use crate::util; +use crate::validate::validate_types; use std::iter; use std::ops::{Range, RangeFrom}; diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 9af48f0bad2..30d4b480f58 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -109,9 +109,9 @@ mod simplify_comparison_integral; mod sroa; mod unreachable_enum_branching; mod unreachable_prop; +mod validate; use rustc_const_eval::transform::check_consts::{self, ConstCx}; -use rustc_const_eval::transform::validate; use rustc_mir_dataflow::rustc_peek; rustc_fluent_macro::fluent_messages! { "../messages.ftl" } diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs new file mode 100644 index 00000000000..66cc65de647 --- /dev/null +++ b/compiler/rustc_mir_transform/src/validate.rs @@ -0,0 +1,1406 @@ +//! Validates the MIR to ensure that invariants are upheld. + +use rustc_data_structures::fx::{FxHashMap, FxHashSet}; +use rustc_index::bit_set::BitSet; +use rustc_index::IndexVec; +use rustc_infer::traits::Reveal; +use rustc_middle::mir::coverage::CoverageKind; +use rustc_middle::mir::interpret::Scalar; +use rustc_middle::mir::visit::{NonUseContext, PlaceContext, Visitor}; +use rustc_middle::mir::*; +use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt, Variance}; +use rustc_middle::{bug, span_bug}; +use rustc_target::abi::{Size, FIRST_VARIANT}; +use rustc_target::spec::abi::Abi; + +use crate::util::is_within_packed; + +use crate::util::relate_types; + +#[derive(Copy, Clone, Debug, PartialEq, Eq)] +enum EdgeKind { + Unwind, + Normal, +} + +pub struct Validator { + /// Describes at which point in the pipeline this validation is happening. + pub when: String, + /// The phase for which we are upholding the dialect. If the given phase forbids a specific + /// element, this validator will now emit errors if that specific element is encountered. + /// Note that phases that change the dialect cause all *following* phases to check the + /// invariants of the new dialect. A phase that changes dialects never checks the new invariants + /// itself. + pub mir_phase: MirPhase, +} + +impl<'tcx> MirPass<'tcx> for Validator { + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + // FIXME(JakobDegen): These bodies never instantiated in codegend anyway, so it's not + // terribly important that they pass the validator. However, I think other passes might + // still see them, in which case they might be surprised. It would probably be better if we + // didn't put this through the MIR pipeline at all. + if matches!(body.source.instance, InstanceDef::Intrinsic(..) | InstanceDef::Virtual(..)) { + return; + } + let def_id = body.source.def_id(); + let mir_phase = self.mir_phase; + let param_env = match mir_phase.reveal() { + Reveal::UserFacing => tcx.param_env(def_id), + Reveal::All => tcx.param_env_reveal_all_normalized(def_id), + }; + + let can_unwind = if mir_phase <= MirPhase::Runtime(RuntimePhase::Initial) { + // In this case `AbortUnwindingCalls` haven't yet been executed. + true + } else if !tcx.def_kind(def_id).is_fn_like() { + true + } else { + let body_ty = tcx.type_of(def_id).skip_binder(); + let body_abi = match body_ty.kind() { + ty::FnDef(..) => body_ty.fn_sig(tcx).abi(), + ty::Closure(..) => Abi::RustCall, + ty::CoroutineClosure(..) => Abi::RustCall, + ty::Coroutine(..) => Abi::Rust, + // No need to do MIR validation on error bodies + ty::Error(_) => return, + _ => { + span_bug!(body.span, "unexpected body ty: {:?} phase {:?}", body_ty, mir_phase) + } + }; + + ty::layout::fn_can_unwind(tcx, Some(def_id), body_abi) + }; + + let mut cfg_checker = CfgChecker { + when: &self.when, + body, + tcx, + mir_phase, + unwind_edge_count: 0, + reachable_blocks: traversal::reachable_as_bitset(body), + value_cache: FxHashSet::default(), + can_unwind, + }; + cfg_checker.visit_body(body); + cfg_checker.check_cleanup_control_flow(); + + // Also run the TypeChecker. + for (location, msg) in validate_types(tcx, self.mir_phase, param_env, body, body) { + cfg_checker.fail(location, msg); + } + + if let MirPhase::Runtime(_) = body.phase { + if let ty::InstanceDef::Item(_) = body.source.instance { + if body.has_free_regions() { + cfg_checker.fail( + Location::START, + format!("Free regions in optimized {} MIR", body.phase.name()), + ); + } + } + } + + // Enforce that coroutine-closure layouts are identical. + if let Some(layout) = body.coroutine_layout_raw() + && let Some(by_move_body) = body.coroutine_by_move_body() + && let Some(by_move_layout) = by_move_body.coroutine_layout_raw() + { + // FIXME(async_closures): We could do other validation here? + if layout.variant_fields.len() != by_move_layout.variant_fields.len() { + cfg_checker.fail( + Location::START, + format!( + "Coroutine layout has different number of variant fields from \ + by-move coroutine layout:\n\ + layout: {layout:#?}\n\ + by_move_layout: {by_move_layout:#?}", + ), + ); + } + } + } +} + +struct CfgChecker<'a, 'tcx> { + when: &'a str, + body: &'a Body<'tcx>, + tcx: TyCtxt<'tcx>, + mir_phase: MirPhase, + unwind_edge_count: usize, + reachable_blocks: BitSet<BasicBlock>, + value_cache: FxHashSet<u128>, + // If `false`, then the MIR must not contain `UnwindAction::Continue` or + // `TerminatorKind::Resume`. + can_unwind: bool, +} + +impl<'a, 'tcx> CfgChecker<'a, 'tcx> { + #[track_caller] + fn fail(&self, location: Location, msg: impl AsRef<str>) { + // We might see broken MIR when other errors have already occurred. + assert!( + self.tcx.dcx().has_errors().is_some(), + "broken MIR in {:?} ({}) at {:?}:\n{}", + self.body.source.instance, + self.when, + location, + msg.as_ref(), + ); + } + + fn check_edge(&mut self, location: Location, bb: BasicBlock, edge_kind: EdgeKind) { + if bb == START_BLOCK { + self.fail(location, "start block must not have predecessors") + } + if let Some(bb) = self.body.basic_blocks.get(bb) { + let src = self.body.basic_blocks.get(location.block).unwrap(); + match (src.is_cleanup, bb.is_cleanup, edge_kind) { + // Non-cleanup blocks can jump to non-cleanup blocks along non-unwind edges + (false, false, EdgeKind::Normal) + // Cleanup blocks can jump to cleanup blocks along non-unwind edges + | (true, true, EdgeKind::Normal) => {} + // Non-cleanup blocks can jump to cleanup blocks along unwind edges + (false, true, EdgeKind::Unwind) => { + self.unwind_edge_count += 1; + } + // All other jumps are invalid + _ => { + self.fail( + location, + format!( + "{:?} edge to {:?} violates unwind invariants (cleanup {:?} -> {:?})", + edge_kind, + bb, + src.is_cleanup, + bb.is_cleanup, + ) + ) + } + } + } else { + self.fail(location, format!("encountered jump to invalid basic block {bb:?}")) + } + } + + fn check_cleanup_control_flow(&self) { + if self.unwind_edge_count <= 1 { + return; + } + let doms = self.body.basic_blocks.dominators(); + let mut post_contract_node = FxHashMap::default(); + // Reusing the allocation across invocations of the closure + let mut dom_path = vec![]; + let mut get_post_contract_node = |mut bb| { + let root = loop { + if let Some(root) = post_contract_node.get(&bb) { + break *root; + } + let parent = doms.immediate_dominator(bb).unwrap(); + dom_path.push(bb); + if !self.body.basic_blocks[parent].is_cleanup { + break bb; + } + bb = parent; + }; + for bb in dom_path.drain(..) { + post_contract_node.insert(bb, root); + } + root + }; + + let mut parent = IndexVec::from_elem(None, &self.body.basic_blocks); + for (bb, bb_data) in self.body.basic_blocks.iter_enumerated() { + if !bb_data.is_cleanup || !self.reachable_blocks.contains(bb) { + continue; + } + let bb = get_post_contract_node(bb); + for s in bb_data.terminator().successors() { + let s = get_post_contract_node(s); + if s == bb { + continue; + } + let parent = &mut parent[bb]; + match parent { + None => { + *parent = Some(s); + } + Some(e) if *e == s => (), + Some(e) => self.fail( + Location { block: bb, statement_index: 0 }, + format!( + "Cleanup control flow violation: The blocks dominated by {:?} have edges to both {:?} and {:?}", + bb, + s, + *e + ) + ), + } + } + } + + // Check for cycles + let mut stack = FxHashSet::default(); + for i in 0..parent.len() { + let mut bb = BasicBlock::from_usize(i); + stack.clear(); + stack.insert(bb); + loop { + let Some(parent) = parent[bb].take() else { break }; + let no_cycle = stack.insert(parent); + if !no_cycle { + self.fail( + Location { block: bb, statement_index: 0 }, + format!( + "Cleanup control flow violation: Cycle involving edge {bb:?} -> {parent:?}", + ), + ); + break; + } + bb = parent; + } + } + } + + fn check_unwind_edge(&mut self, location: Location, unwind: UnwindAction) { + let is_cleanup = self.body.basic_blocks[location.block].is_cleanup; + match unwind { + UnwindAction::Cleanup(unwind) => { + if is_cleanup { + self.fail(location, "`UnwindAction::Cleanup` in cleanup block"); + } + self.check_edge(location, unwind, EdgeKind::Unwind); + } + UnwindAction::Continue => { + if is_cleanup { + self.fail(location, "`UnwindAction::Continue` in cleanup block"); + } + + if !self.can_unwind { + self.fail(location, "`UnwindAction::Continue` in no-unwind function"); + } + } + UnwindAction::Terminate(UnwindTerminateReason::InCleanup) => { + if !is_cleanup { + self.fail( + location, + "`UnwindAction::Terminate(InCleanup)` in a non-cleanup block", + ); + } + } + // These are allowed everywhere. + UnwindAction::Unreachable | UnwindAction::Terminate(UnwindTerminateReason::Abi) => (), + } + } + + fn is_critical_call_edge(&self, target: Option<BasicBlock>, unwind: UnwindAction) -> bool { + let Some(target) = target else { return false }; + matches!(unwind, UnwindAction::Cleanup(_) | UnwindAction::Terminate(_)) + && self.body.basic_blocks.predecessors()[target].len() > 1 + } +} + +impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> { + fn visit_local(&mut self, local: Local, _context: PlaceContext, location: Location) { + if self.body.local_decls.get(local).is_none() { + self.fail( + location, + format!("local {local:?} has no corresponding declaration in `body.local_decls`"), + ); + } + } + + fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) { + match &statement.kind { + StatementKind::AscribeUserType(..) => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`AscribeUserType` should have been removed after drop lowering phase", + ); + } + } + StatementKind::FakeRead(..) => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`FakeRead` should have been removed after drop lowering phase", + ); + } + } + StatementKind::SetDiscriminant { .. } => { + if self.mir_phase < MirPhase::Runtime(RuntimePhase::Initial) { + self.fail(location, "`SetDiscriminant`is not allowed until deaggregation"); + } + } + StatementKind::Deinit(..) => { + if self.mir_phase < MirPhase::Runtime(RuntimePhase::Initial) { + self.fail(location, "`Deinit`is not allowed until deaggregation"); + } + } + StatementKind::Retag(kind, _) => { + // FIXME(JakobDegen) The validator should check that `self.mir_phase < + // DropsLowered`. However, this causes ICEs with generation of drop shims, which + // seem to fail to set their `MirPhase` correctly. + if matches!(kind, RetagKind::TwoPhase) { + self.fail(location, format!("explicit `{kind:?}` is forbidden")); + } + } + StatementKind::Coverage(kind) => { + if self.mir_phase >= MirPhase::Analysis(AnalysisPhase::PostCleanup) + && let CoverageKind::BlockMarker { .. } | CoverageKind::SpanMarker { .. } = kind + { + self.fail( + location, + format!("{kind:?} should have been removed after analysis"), + ); + } + } + StatementKind::Assign(..) + | StatementKind::StorageLive(_) + | StatementKind::StorageDead(_) + | StatementKind::Intrinsic(_) + | StatementKind::ConstEvalCounter + | StatementKind::PlaceMention(..) + | StatementKind::Nop => {} + } + + self.super_statement(statement, location); + } + + fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) { + match &terminator.kind { + TerminatorKind::Goto { target } => { + self.check_edge(location, *target, EdgeKind::Normal); + } + TerminatorKind::SwitchInt { targets, discr: _ } => { + for (_, target) in targets.iter() { + self.check_edge(location, target, EdgeKind::Normal); + } + self.check_edge(location, targets.otherwise(), EdgeKind::Normal); + + self.value_cache.clear(); + self.value_cache.extend(targets.iter().map(|(value, _)| value)); + let has_duplicates = targets.iter().len() != self.value_cache.len(); + if has_duplicates { + self.fail( + location, + format!( + "duplicated values in `SwitchInt` terminator: {:?}", + terminator.kind, + ), + ); + } + } + TerminatorKind::Drop { target, unwind, .. } => { + self.check_edge(location, *target, EdgeKind::Normal); + self.check_unwind_edge(location, *unwind); + } + TerminatorKind::Call { args, destination, target, unwind, .. } => { + if let Some(target) = target { + self.check_edge(location, *target, EdgeKind::Normal); + } + self.check_unwind_edge(location, *unwind); + + // The code generation assumes that there are no critical call edges. The assumption + // is used to simplify inserting code that should be executed along the return edge + // from the call. FIXME(tmiasko): Since this is a strictly code generation concern, + // the code generation should be responsible for handling it. + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Optimized) + && self.is_critical_call_edge(*target, *unwind) + { + self.fail( + location, + format!( + "encountered critical edge in `Call` terminator {:?}", + terminator.kind, + ), + ); + } + + // The call destination place and Operand::Move place used as an argument might be + // passed by a reference to the callee. Consequently they cannot be packed. + if is_within_packed(self.tcx, &self.body.local_decls, *destination).is_some() { + // This is bad! The callee will expect the memory to be aligned. + self.fail( + location, + format!( + "encountered packed place in `Call` terminator destination: {:?}", + terminator.kind, + ), + ); + } + for arg in args { + if let Operand::Move(place) = &arg.node { + if is_within_packed(self.tcx, &self.body.local_decls, *place).is_some() { + // This is bad! The callee will expect the memory to be aligned. + self.fail( + location, + format!( + "encountered `Move` of a packed place in `Call` terminator: {:?}", + terminator.kind, + ), + ); + } + } + } + } + TerminatorKind::Assert { target, unwind, .. } => { + self.check_edge(location, *target, EdgeKind::Normal); + self.check_unwind_edge(location, *unwind); + } + TerminatorKind::Yield { resume, drop, .. } => { + if self.body.coroutine.is_none() { + self.fail(location, "`Yield` cannot appear outside coroutine bodies"); + } + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail(location, "`Yield` should have been replaced by coroutine lowering"); + } + self.check_edge(location, *resume, EdgeKind::Normal); + if let Some(drop) = drop { + self.check_edge(location, *drop, EdgeKind::Normal); + } + } + TerminatorKind::FalseEdge { real_target, imaginary_target } => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`FalseEdge` should have been removed after drop elaboration", + ); + } + self.check_edge(location, *real_target, EdgeKind::Normal); + self.check_edge(location, *imaginary_target, EdgeKind::Normal); + } + TerminatorKind::FalseUnwind { real_target, unwind } => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`FalseUnwind` should have been removed after drop elaboration", + ); + } + self.check_edge(location, *real_target, EdgeKind::Normal); + self.check_unwind_edge(location, *unwind); + } + TerminatorKind::InlineAsm { targets, unwind, .. } => { + for &target in targets { + self.check_edge(location, target, EdgeKind::Normal); + } + self.check_unwind_edge(location, *unwind); + } + TerminatorKind::CoroutineDrop => { + if self.body.coroutine.is_none() { + self.fail(location, "`CoroutineDrop` cannot appear outside coroutine bodies"); + } + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`CoroutineDrop` should have been replaced by coroutine lowering", + ); + } + } + TerminatorKind::UnwindResume => { + let bb = location.block; + if !self.body.basic_blocks[bb].is_cleanup { + self.fail(location, "Cannot `UnwindResume` from non-cleanup basic block") + } + if !self.can_unwind { + self.fail(location, "Cannot `UnwindResume` in a function that cannot unwind") + } + } + TerminatorKind::UnwindTerminate(_) => { + let bb = location.block; + if !self.body.basic_blocks[bb].is_cleanup { + self.fail(location, "Cannot `UnwindTerminate` from non-cleanup basic block") + } + } + TerminatorKind::Return => { + let bb = location.block; + if self.body.basic_blocks[bb].is_cleanup { + self.fail(location, "Cannot `Return` from cleanup basic block") + } + } + TerminatorKind::Unreachable => {} + } + + self.super_terminator(terminator, location); + } + + fn visit_source_scope(&mut self, scope: SourceScope) { + if self.body.source_scopes.get(scope).is_none() { + self.tcx.dcx().span_bug( + self.body.span, + format!( + "broken MIR in {:?} ({}):\ninvalid source scope {:?}", + self.body.source.instance, self.when, scope, + ), + ); + } + } +} + +/// A faster version of the validation pass that only checks those things which may break when +/// instantiating any generic parameters. +/// +/// `caller_body` is used to detect cycles in MIR inlining and MIR validation before +/// `optimized_mir` is available. +pub fn validate_types<'tcx>( + tcx: TyCtxt<'tcx>, + mir_phase: MirPhase, + param_env: ty::ParamEnv<'tcx>, + body: &Body<'tcx>, + caller_body: &Body<'tcx>, +) -> Vec<(Location, String)> { + let mut type_checker = + TypeChecker { body, caller_body, tcx, param_env, mir_phase, failures: Vec::new() }; + type_checker.visit_body(body); + type_checker.failures +} + +struct TypeChecker<'a, 'tcx> { + body: &'a Body<'tcx>, + caller_body: &'a Body<'tcx>, + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + mir_phase: MirPhase, + failures: Vec<(Location, String)>, +} + +impl<'a, 'tcx> TypeChecker<'a, 'tcx> { + fn fail(&mut self, location: Location, msg: impl Into<String>) { + self.failures.push((location, msg.into())); + } + + /// Check if src can be assigned into dest. + /// This is not precise, it will accept some incorrect assignments. + fn mir_assign_valid_types(&self, src: Ty<'tcx>, dest: Ty<'tcx>) -> bool { + // Fast path before we normalize. + if src == dest { + // Equal types, all is good. + return true; + } + + // We sometimes have to use `defining_opaque_types` for subtyping + // to succeed here and figuring out how exactly that should work + // is annoying. It is harmless enough to just not validate anything + // in that case. We still check this after analysis as all opaque + // types have been revealed at this point. + if (src, dest).has_opaque_types() { + return true; + } + + // After borrowck subtyping should be fully explicit via + // `Subtype` projections. + let variance = if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + Variance::Invariant + } else { + Variance::Covariant + }; + + crate::util::relate_types(self.tcx, self.param_env, variance, src, dest) + } +} + +impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { + fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location) { + // This check is somewhat expensive, so only run it when -Zvalidate-mir is passed. + if self.tcx.sess.opts.unstable_opts.validate_mir + && self.mir_phase < MirPhase::Runtime(RuntimePhase::Initial) + { + // `Operand::Copy` is only supposed to be used with `Copy` types. + if let Operand::Copy(place) = operand { + let ty = place.ty(&self.body.local_decls, self.tcx).ty; + + if !ty.is_copy_modulo_regions(self.tcx, self.param_env) { + self.fail(location, format!("`Operand::Copy` with non-`Copy` type {ty}")); + } + } + } + + self.super_operand(operand, location); + } + + fn visit_projection_elem( + &mut self, + place_ref: PlaceRef<'tcx>, + elem: PlaceElem<'tcx>, + context: PlaceContext, + location: Location, + ) { + match elem { + ProjectionElem::OpaqueCast(ty) + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) => + { + self.fail( + location, + format!("explicit opaque type cast to `{ty}` after `RevealAll`"), + ) + } + ProjectionElem::Index(index) => { + let index_ty = self.body.local_decls[index].ty; + if index_ty != self.tcx.types.usize { + self.fail(location, format!("bad index ({index_ty:?} != usize)")) + } + } + ProjectionElem::Deref + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::PostCleanup) => + { + let base_ty = place_ref.ty(&self.body.local_decls, self.tcx).ty; + + if base_ty.is_box() { + self.fail( + location, + format!("{base_ty:?} dereferenced after ElaborateBoxDerefs"), + ) + } + } + ProjectionElem::Field(f, ty) => { + let parent_ty = place_ref.ty(&self.body.local_decls, self.tcx); + let fail_out_of_bounds = |this: &mut Self, location| { + this.fail(location, format!("Out of bounds field {f:?} for {parent_ty:?}")); + }; + let check_equal = |this: &mut Self, location, f_ty| { + if !this.mir_assign_valid_types(ty, f_ty) { + this.fail( + location, + format!( + "Field projection `{place_ref:?}.{f:?}` specified type `{ty:?}`, but actual type is `{f_ty:?}`" + ) + ) + } + }; + + let kind = match parent_ty.ty.kind() { + &ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => { + self.tcx.type_of(def_id).instantiate(self.tcx, args).kind() + } + kind => kind, + }; + + match kind { + ty::Tuple(fields) => { + let Some(f_ty) = fields.get(f.as_usize()) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, *f_ty); + } + ty::Adt(adt_def, args) => { + // see <https://github.com/rust-lang/rust/blob/7601adcc764d42c9f2984082b49948af652df986/compiler/rustc_middle/src/ty/layout.rs#L861-L864> + if Some(adt_def.did()) == self.tcx.lang_items().dyn_metadata() { + self.fail( + location, + format!("You can't project to field {f:?} of `DynMetadata` because \ + layout is weird and thinks it doesn't have fields."), + ); + } + + let var = parent_ty.variant_index.unwrap_or(FIRST_VARIANT); + let Some(field) = adt_def.variant(var).fields.get(f) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, field.ty(self.tcx, args)); + } + ty::Closure(_, args) => { + let args = args.as_closure(); + let Some(&f_ty) = args.upvar_tys().get(f.as_usize()) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, f_ty); + } + ty::CoroutineClosure(_, args) => { + let args = args.as_coroutine_closure(); + let Some(&f_ty) = args.upvar_tys().get(f.as_usize()) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, f_ty); + } + &ty::Coroutine(def_id, args) => { + let f_ty = if let Some(var) = parent_ty.variant_index { + // If we're currently validating an inlined copy of this body, + // then it will no longer be parameterized over the original + // args of the coroutine. Otherwise, we prefer to use this body + // since we may be in the process of computing this MIR in the + // first place. + let layout = if def_id == self.caller_body.source.def_id() { + // FIXME: This is not right for async closures. + self.caller_body.coroutine_layout_raw() + } else { + self.tcx.coroutine_layout(def_id, args.as_coroutine().kind_ty()) + }; + + let Some(layout) = layout else { + self.fail( + location, + format!("No coroutine layout for {parent_ty:?}"), + ); + return; + }; + + let Some(&local) = layout.variant_fields[var].get(f) else { + fail_out_of_bounds(self, location); + return; + }; + + let Some(f_ty) = layout.field_tys.get(local) else { + self.fail( + location, + format!("Out of bounds local {local:?} for {parent_ty:?}"), + ); + return; + }; + + ty::EarlyBinder::bind(f_ty.ty).instantiate(self.tcx, args) + } else { + let Some(&f_ty) = args.as_coroutine().prefix_tys().get(f.index()) + else { + fail_out_of_bounds(self, location); + return; + }; + + f_ty + }; + + check_equal(self, location, f_ty); + } + _ => { + self.fail(location, format!("{:?} does not have fields", parent_ty.ty)); + } + } + } + ProjectionElem::Subtype(ty) => { + if !relate_types( + self.tcx, + self.param_env, + Variance::Covariant, + ty, + place_ref.ty(&self.body.local_decls, self.tcx).ty, + ) { + self.fail( + location, + format!( + "Failed subtyping {ty:#?} and {:#?}", + place_ref.ty(&self.body.local_decls, self.tcx).ty + ), + ) + } + } + _ => {} + } + self.super_projection_elem(place_ref, elem, context, location); + } + + fn visit_var_debug_info(&mut self, debuginfo: &VarDebugInfo<'tcx>) { + if let Some(box VarDebugInfoFragment { ty, ref projection }) = debuginfo.composite { + if ty.is_union() || ty.is_enum() { + self.fail( + START_BLOCK.start_location(), + format!("invalid type {ty:?} in debuginfo for {:?}", debuginfo.name), + ); + } + if projection.is_empty() { + self.fail( + START_BLOCK.start_location(), + format!("invalid empty projection in debuginfo for {:?}", debuginfo.name), + ); + } + if projection.iter().any(|p| !matches!(p, PlaceElem::Field(..))) { + self.fail( + START_BLOCK.start_location(), + format!( + "illegal projection {:?} in debuginfo for {:?}", + projection, debuginfo.name + ), + ); + } + } + match debuginfo.value { + VarDebugInfoContents::Const(_) => {} + VarDebugInfoContents::Place(place) => { + if place.projection.iter().any(|p| !p.can_use_in_debuginfo()) { + self.fail( + START_BLOCK.start_location(), + format!("illegal place {:?} in debuginfo for {:?}", place, debuginfo.name), + ); + } + } + } + self.super_var_debug_info(debuginfo); + } + + fn visit_place(&mut self, place: &Place<'tcx>, cntxt: PlaceContext, location: Location) { + // Set off any `bug!`s in the type computation code + let _ = place.ty(&self.body.local_decls, self.tcx); + + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) + && place.projection.len() > 1 + && cntxt != PlaceContext::NonUse(NonUseContext::VarDebugInfo) + && place.projection[1..].contains(&ProjectionElem::Deref) + { + self.fail(location, format!("{place:?}, has deref at the wrong place")); + } + + self.super_place(place, cntxt, location); + } + + fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) { + macro_rules! check_kinds { + ($t:expr, $text:literal, $typat:pat) => { + if !matches!(($t).kind(), $typat) { + self.fail(location, format!($text, $t)); + } + }; + } + match rvalue { + Rvalue::Use(_) | Rvalue::CopyForDeref(_) => {} + Rvalue::Aggregate(kind, fields) => match **kind { + AggregateKind::Tuple => {} + AggregateKind::Array(dest) => { + for src in fields { + if !self.mir_assign_valid_types(src.ty(self.body, self.tcx), dest) { + self.fail(location, "array field has the wrong type"); + } + } + } + AggregateKind::Adt(def_id, idx, args, _, Some(field)) => { + let adt_def = self.tcx.adt_def(def_id); + assert!(adt_def.is_union()); + assert_eq!(idx, FIRST_VARIANT); + let dest_ty = self.tcx.normalize_erasing_regions( + self.param_env, + adt_def.non_enum_variant().fields[field].ty(self.tcx, args), + ); + if fields.len() == 1 { + let src_ty = fields.raw[0].ty(self.body, self.tcx); + if !self.mir_assign_valid_types(src_ty, dest_ty) { + self.fail(location, "union field has the wrong type"); + } + } else { + self.fail(location, "unions should have one initialized field"); + } + } + AggregateKind::Adt(def_id, idx, args, _, None) => { + let adt_def = self.tcx.adt_def(def_id); + assert!(!adt_def.is_union()); + let variant = &adt_def.variants()[idx]; + if variant.fields.len() != fields.len() { + self.fail(location, "adt has the wrong number of initialized fields"); + } + for (src, dest) in std::iter::zip(fields, &variant.fields) { + let dest_ty = self + .tcx + .normalize_erasing_regions(self.param_env, dest.ty(self.tcx, args)); + if !self.mir_assign_valid_types(src.ty(self.body, self.tcx), dest_ty) { + self.fail(location, "adt field has the wrong type"); + } + } + } + AggregateKind::Closure(_, args) => { + let upvars = args.as_closure().upvar_tys(); + if upvars.len() != fields.len() { + self.fail(location, "closure has the wrong number of initialized fields"); + } + for (src, dest) in std::iter::zip(fields, upvars) { + if !self.mir_assign_valid_types(src.ty(self.body, self.tcx), dest) { + self.fail(location, "closure field has the wrong type"); + } + } + } + AggregateKind::Coroutine(_, args) => { + let upvars = args.as_coroutine().upvar_tys(); + if upvars.len() != fields.len() { + self.fail(location, "coroutine has the wrong number of initialized fields"); + } + for (src, dest) in std::iter::zip(fields, upvars) { + if !self.mir_assign_valid_types(src.ty(self.body, self.tcx), dest) { + self.fail(location, "coroutine field has the wrong type"); + } + } + } + AggregateKind::CoroutineClosure(_, args) => { + let upvars = args.as_coroutine_closure().upvar_tys(); + if upvars.len() != fields.len() { + self.fail( + location, + "coroutine-closure has the wrong number of initialized fields", + ); + } + for (src, dest) in std::iter::zip(fields, upvars) { + if !self.mir_assign_valid_types(src.ty(self.body, self.tcx), dest) { + self.fail(location, "coroutine-closure field has the wrong type"); + } + } + } + AggregateKind::RawPtr(pointee_ty, mutability) => { + if !matches!(self.mir_phase, MirPhase::Runtime(_)) { + // It would probably be fine to support this in earlier phases, + // but at the time of writing it's only ever introduced from intrinsic lowering, + // so earlier things just `bug!` on it. + self.fail(location, "RawPtr should be in runtime MIR only"); + } + + if fields.len() != 2 { + self.fail(location, "raw pointer aggregate must have 2 fields"); + } else { + let data_ptr_ty = fields.raw[0].ty(self.body, self.tcx); + let metadata_ty = fields.raw[1].ty(self.body, self.tcx); + if let ty::RawPtr(in_pointee, in_mut) = data_ptr_ty.kind() { + if *in_mut != mutability { + self.fail(location, "input and output mutability must match"); + } + + // FIXME: check `Thin` instead of `Sized` + if !in_pointee.is_sized(self.tcx, self.param_env) { + self.fail(location, "input pointer must be thin"); + } + } else { + self.fail( + location, + "first operand to raw pointer aggregate must be a raw pointer", + ); + } + + // FIXME: Check metadata more generally + if pointee_ty.is_slice() { + if !self.mir_assign_valid_types(metadata_ty, self.tcx.types.usize) { + self.fail(location, "slice metadata must be usize"); + } + } else if pointee_ty.is_sized(self.tcx, self.param_env) { + if metadata_ty != self.tcx.types.unit { + self.fail(location, "metadata for pointer-to-thin must be unit"); + } + } + } + } + }, + Rvalue::Ref(_, BorrowKind::Fake(_), _) => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`Assign` statement with a `Fake` borrow should have been removed in runtime MIR", + ); + } + } + Rvalue::Ref(..) => {} + Rvalue::Len(p) => { + let pty = p.ty(&self.body.local_decls, self.tcx).ty; + check_kinds!( + pty, + "Cannot compute length of non-array type {:?}", + ty::Array(..) | ty::Slice(..) + ); + } + Rvalue::BinaryOp(op, vals) => { + use BinOp::*; + let a = vals.0.ty(&self.body.local_decls, self.tcx); + let b = vals.1.ty(&self.body.local_decls, self.tcx); + if crate::util::binop_right_homogeneous(*op) { + if let Eq | Lt | Le | Ne | Ge | Gt = op { + // The function pointer types can have lifetimes + if !self.mir_assign_valid_types(a, b) { + self.fail( + location, + format!("Cannot {op:?} compare incompatible types {a:?} and {b:?}"), + ); + } + } else if a != b { + self.fail( + location, + format!( + "Cannot perform binary op {op:?} on unequal types {a:?} and {b:?}" + ), + ); + } + } + + match op { + Offset => { + check_kinds!(a, "Cannot offset non-pointer type {:?}", ty::RawPtr(..)); + if b != self.tcx.types.isize && b != self.tcx.types.usize { + self.fail(location, format!("Cannot offset by non-isize type {b:?}")); + } + } + Eq | Lt | Le | Ne | Ge | Gt => { + for x in [a, b] { + check_kinds!( + x, + "Cannot {op:?} compare type {:?}", + ty::Bool + | ty::Char + | ty::Int(..) + | ty::Uint(..) + | ty::Float(..) + | ty::RawPtr(..) + | ty::FnPtr(..) + ) + } + } + Cmp => { + for x in [a, b] { + check_kinds!( + x, + "Cannot three-way compare non-integer type {:?}", + ty::Char | ty::Uint(..) | ty::Int(..) + ) + } + } + AddUnchecked | AddWithOverflow | SubUnchecked | SubWithOverflow + | MulUnchecked | MulWithOverflow | Shl | ShlUnchecked | Shr | ShrUnchecked => { + for x in [a, b] { + check_kinds!( + x, + "Cannot {op:?} non-integer type {:?}", + ty::Uint(..) | ty::Int(..) + ) + } + } + BitAnd | BitOr | BitXor => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform bitwise op {op:?} on type {:?}", + ty::Uint(..) | ty::Int(..) | ty::Bool + ) + } + } + Add | Sub | Mul | Div | Rem => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform arithmetic {op:?} on type {:?}", + ty::Uint(..) | ty::Int(..) | ty::Float(..) + ) + } + } + } + } + Rvalue::UnaryOp(op, operand) => { + let a = operand.ty(&self.body.local_decls, self.tcx); + match op { + UnOp::Neg => { + check_kinds!(a, "Cannot negate type {:?}", ty::Int(..) | ty::Float(..)) + } + UnOp::Not => { + check_kinds!( + a, + "Cannot binary not type {:?}", + ty::Int(..) | ty::Uint(..) | ty::Bool + ); + } + } + } + Rvalue::ShallowInitBox(operand, _) => { + let a = operand.ty(&self.body.local_decls, self.tcx); + check_kinds!(a, "Cannot shallow init type {:?}", ty::RawPtr(..)); + } + Rvalue::Cast(kind, operand, target_type) => { + let op_ty = operand.ty(self.body, self.tcx); + match kind { + CastKind::DynStar => { + // FIXME(dyn-star): make sure nothing needs to be done here. + } + // FIXME: Add Checks for these + CastKind::PointerWithExposedProvenance + | CastKind::PointerExposeProvenance + | CastKind::PointerCoercion(_) => {} + CastKind::IntToInt | CastKind::IntToFloat => { + let input_valid = op_ty.is_integral() || op_ty.is_char() || op_ty.is_bool(); + let target_valid = target_type.is_numeric() || target_type.is_char(); + if !input_valid || !target_valid { + self.fail( + location, + format!("Wrong cast kind {kind:?} for the type {op_ty}",), + ); + } + } + CastKind::FnPtrToPtr | CastKind::PtrToPtr => { + if !(op_ty.is_any_ptr() && target_type.is_unsafe_ptr()) { + self.fail(location, "Can't cast {op_ty} into 'Ptr'"); + } + } + CastKind::FloatToFloat | CastKind::FloatToInt => { + if !op_ty.is_floating_point() || !target_type.is_numeric() { + self.fail( + location, + format!( + "Trying to cast non 'Float' as {kind:?} into {target_type:?}" + ), + ); + } + } + CastKind::Transmute => { + if let MirPhase::Runtime(..) = self.mir_phase { + // Unlike `mem::transmute`, a MIR `Transmute` is well-formed + // for any two `Sized` types, just potentially UB to run. + + if !self + .tcx + .normalize_erasing_regions(self.param_env, op_ty) + .is_sized(self.tcx, self.param_env) + { + self.fail( + location, + format!("Cannot transmute from non-`Sized` type {op_ty:?}"), + ); + } + if !self + .tcx + .normalize_erasing_regions(self.param_env, *target_type) + .is_sized(self.tcx, self.param_env) + { + self.fail( + location, + format!("Cannot transmute to non-`Sized` type {target_type:?}"), + ); + } + } else { + self.fail( + location, + format!( + "Transmute is not supported in non-runtime phase {:?}.", + self.mir_phase + ), + ); + } + } + } + } + Rvalue::NullaryOp(NullOp::OffsetOf(indices), container) => { + let fail_out_of_bounds = |this: &mut Self, location, field, ty| { + this.fail(location, format!("Out of bounds field {field:?} for {ty:?}")); + }; + + let mut current_ty = *container; + + for (variant, field) in indices.iter() { + match current_ty.kind() { + ty::Tuple(fields) => { + if variant != FIRST_VARIANT { + self.fail( + location, + format!("tried to get variant {variant:?} of tuple"), + ); + return; + } + let Some(&f_ty) = fields.get(field.as_usize()) else { + fail_out_of_bounds(self, location, field, current_ty); + return; + }; + + current_ty = self.tcx.normalize_erasing_regions(self.param_env, f_ty); + } + ty::Adt(adt_def, args) => { + let Some(field) = adt_def.variant(variant).fields.get(field) else { + fail_out_of_bounds(self, location, field, current_ty); + return; + }; + + let f_ty = field.ty(self.tcx, args); + current_ty = self.tcx.normalize_erasing_regions(self.param_env, f_ty); + } + _ => { + self.fail( + location, + format!("Cannot get offset ({variant:?}, {field:?}) from type {current_ty:?}"), + ); + return; + } + } + } + } + Rvalue::Repeat(_, _) + | Rvalue::ThreadLocalRef(_) + | Rvalue::AddressOf(_, _) + | Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf | NullOp::UbChecks, _) + | Rvalue::Discriminant(_) => {} + } + self.super_rvalue(rvalue, location); + } + + fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) { + match &statement.kind { + StatementKind::Assign(box (dest, rvalue)) => { + // LHS and RHS of the assignment must have the same type. + let left_ty = dest.ty(&self.body.local_decls, self.tcx).ty; + let right_ty = rvalue.ty(&self.body.local_decls, self.tcx); + + if !self.mir_assign_valid_types(right_ty, left_ty) { + self.fail( + location, + format!( + "encountered `{:?}` with incompatible types:\n\ + left-hand side has type: {}\n\ + right-hand side has type: {}", + statement.kind, left_ty, right_ty, + ), + ); + } + if let Rvalue::CopyForDeref(place) = rvalue { + if place.ty(&self.body.local_decls, self.tcx).ty.builtin_deref(true).is_none() { + self.fail( + location, + "`CopyForDeref` should only be used for dereferenceable types", + ) + } + } + } + StatementKind::AscribeUserType(..) => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`AscribeUserType` should have been removed after drop lowering phase", + ); + } + } + StatementKind::FakeRead(..) => { + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + self.fail( + location, + "`FakeRead` should have been removed after drop lowering phase", + ); + } + } + StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume(op)) => { + let ty = op.ty(&self.body.local_decls, self.tcx); + if !ty.is_bool() { + self.fail( + location, + format!("`assume` argument must be `bool`, but got: `{ty}`"), + ); + } + } + StatementKind::Intrinsic(box NonDivergingIntrinsic::CopyNonOverlapping( + CopyNonOverlapping { src, dst, count }, + )) => { + let src_ty = src.ty(&self.body.local_decls, self.tcx); + let op_src_ty = if let Some(src_deref) = src_ty.builtin_deref(true) { + src_deref + } else { + self.fail( + location, + format!("Expected src to be ptr in copy_nonoverlapping, got: {src_ty}"), + ); + return; + }; + let dst_ty = dst.ty(&self.body.local_decls, self.tcx); + let op_dst_ty = if let Some(dst_deref) = dst_ty.builtin_deref(true) { + dst_deref + } else { + self.fail( + location, + format!("Expected dst to be ptr in copy_nonoverlapping, got: {dst_ty}"), + ); + return; + }; + // since CopyNonOverlapping is parametrized by 1 type, + // we only need to check that they are equal and not keep an extra parameter. + if !self.mir_assign_valid_types(op_src_ty, op_dst_ty) { + self.fail(location, format!("bad arg ({op_src_ty:?} != {op_dst_ty:?})")); + } + + let op_cnt_ty = count.ty(&self.body.local_decls, self.tcx); + if op_cnt_ty != self.tcx.types.usize { + self.fail(location, format!("bad arg ({op_cnt_ty:?} != usize)")) + } + } + StatementKind::SetDiscriminant { place, .. } => { + if self.mir_phase < MirPhase::Runtime(RuntimePhase::Initial) { + self.fail(location, "`SetDiscriminant`is not allowed until deaggregation"); + } + let pty = place.ty(&self.body.local_decls, self.tcx).ty.kind(); + if !matches!(pty, ty::Adt(..) | ty::Coroutine(..) | ty::Alias(ty::Opaque, ..)) { + self.fail( + location, + format!( + "`SetDiscriminant` is only allowed on ADTs and coroutines, not {pty:?}" + ), + ); + } + } + StatementKind::Deinit(..) => { + if self.mir_phase < MirPhase::Runtime(RuntimePhase::Initial) { + self.fail(location, "`Deinit`is not allowed until deaggregation"); + } + } + StatementKind::Retag(kind, _) => { + // FIXME(JakobDegen) The validator should check that `self.mir_phase < + // DropsLowered`. However, this causes ICEs with generation of drop shims, which + // seem to fail to set their `MirPhase` correctly. + if matches!(kind, RetagKind::TwoPhase) { + self.fail(location, format!("explicit `{kind:?}` is forbidden")); + } + } + StatementKind::StorageLive(_) + | StatementKind::StorageDead(_) + | StatementKind::Coverage(_) + | StatementKind::ConstEvalCounter + | StatementKind::PlaceMention(..) + | StatementKind::Nop => {} + } + + self.super_statement(statement, location); + } + + fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) { + match &terminator.kind { + TerminatorKind::SwitchInt { targets, discr } => { + let switch_ty = discr.ty(&self.body.local_decls, self.tcx); + + let target_width = self.tcx.sess.target.pointer_width; + + let size = Size::from_bits(match switch_ty.kind() { + ty::Uint(uint) => uint.normalize(target_width).bit_width().unwrap(), + ty::Int(int) => int.normalize(target_width).bit_width().unwrap(), + ty::Char => 32, + ty::Bool => 1, + other => bug!("unhandled type: {:?}", other), + }); + + for (value, _) in targets.iter() { + if Scalar::<()>::try_from_uint(value, size).is_none() { + self.fail( + location, + format!("the value {value:#x} is not a proper {switch_ty:?}"), + ) + } + } + } + TerminatorKind::Call { func, .. } => { + let func_ty = func.ty(&self.body.local_decls, self.tcx); + match func_ty.kind() { + ty::FnPtr(..) | ty::FnDef(..) => {} + _ => self.fail( + location, + format!("encountered non-callable type {func_ty} in `Call` terminator"), + ), + } + } + TerminatorKind::Assert { cond, .. } => { + let cond_ty = cond.ty(&self.body.local_decls, self.tcx); + if cond_ty != self.tcx.types.bool { + self.fail( + location, + format!( + "encountered non-boolean condition of type {cond_ty} in `Assert` terminator" + ), + ); + } + } + TerminatorKind::Goto { .. } + | TerminatorKind::Drop { .. } + | TerminatorKind::Yield { .. } + | TerminatorKind::FalseEdge { .. } + | TerminatorKind::FalseUnwind { .. } + | TerminatorKind::InlineAsm { .. } + | TerminatorKind::CoroutineDrop + | TerminatorKind::UnwindResume + | TerminatorKind::UnwindTerminate(_) + | TerminatorKind::Return + | TerminatorKind::Unreachable => {} + } + + self.super_terminator(terminator, location); + } +} |