diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /compiler/rustc_const_eval/src/transform/validate.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | compiler/rustc_const_eval/src/transform/validate.rs | 913 |
1 files changed, 913 insertions, 0 deletions
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs new file mode 100644 index 000000000..15e820f2d --- /dev/null +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -0,0 +1,913 @@ +//! Validates the MIR to ensure that invariants are upheld. + +use rustc_data_structures::fx::FxHashSet; +use rustc_index::bit_set::BitSet; +use rustc_infer::infer::TyCtxtInferExt; +use rustc_middle::mir::interpret::Scalar; +use rustc_middle::mir::visit::NonUseContext::VarDebugInfo; +use rustc_middle::mir::visit::{PlaceContext, Visitor}; +use rustc_middle::mir::{ + traversal, AggregateKind, BasicBlock, BinOp, Body, BorrowKind, CastKind, Local, Location, + MirPass, MirPhase, Operand, Place, PlaceElem, PlaceRef, ProjectionElem, Rvalue, SourceScope, + Statement, StatementKind, Terminator, TerminatorKind, UnOp, START_BLOCK, +}; +use rustc_middle::ty::fold::BottomUpFolder; +use rustc_middle::ty::subst::Subst; +use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeFoldable, TypeVisitable}; +use rustc_mir_dataflow::impls::MaybeStorageLive; +use rustc_mir_dataflow::storage::always_storage_live_locals; +use rustc_mir_dataflow::{Analysis, ResultsCursor}; +use rustc_target::abi::{Size, VariantIdx}; + +#[derive(Copy, Clone, Debug)] +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 param_env = tcx.param_env(def_id); + let mir_phase = self.mir_phase; + + let always_live_locals = always_storage_live_locals(body); + let storage_liveness = MaybeStorageLive::new(always_live_locals) + .into_engine(tcx, body) + .iterate_to_fixpoint() + .into_results_cursor(body); + + TypeChecker { + when: &self.when, + body, + tcx, + param_env, + mir_phase, + reachable_blocks: traversal::reachable_as_bitset(body), + storage_liveness, + place_cache: Vec::new(), + value_cache: Vec::new(), + } + .visit_body(body); + } +} + +/// Returns whether the two types are equal up to lifetimes. +/// All lifetimes, including higher-ranked ones, get ignored for this comparison. +/// (This is unlike the `erasing_regions` methods, which keep higher-ranked lifetimes for soundness reasons.) +/// +/// The point of this function is to approximate "equal up to subtyping". However, +/// the approximation is incorrect as variance is ignored. +pub fn equal_up_to_regions<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + src: Ty<'tcx>, + dest: Ty<'tcx>, +) -> bool { + // Fast path. + if src == dest { + return true; + } + + // Normalize lifetimes away on both sides, then compare. + let normalize = |ty: Ty<'tcx>| { + tcx.normalize_erasing_regions( + param_env, + ty.fold_with(&mut BottomUpFolder { + tcx, + // FIXME: We erase all late-bound lifetimes, but this is not fully correct. + // If you have a type like `<for<'a> fn(&'a u32) as SomeTrait>::Assoc`, + // this is not necessarily equivalent to `<fn(&'static u32) as SomeTrait>::Assoc`, + // since one may have an `impl SomeTrait for fn(&32)` and + // `impl SomeTrait for fn(&'static u32)` at the same time which + // specify distinct values for Assoc. (See also #56105) + lt_op: |_| tcx.lifetimes.re_erased, + // Leave consts and types unchanged. + ct_op: |ct| ct, + ty_op: |ty| ty, + }), + ) + }; + tcx.infer_ctxt().enter(|infcx| infcx.can_eq(param_env, normalize(src), normalize(dest)).is_ok()) +} + +struct TypeChecker<'a, 'tcx> { + when: &'a str, + body: &'a Body<'tcx>, + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + mir_phase: MirPhase, + reachable_blocks: BitSet<BasicBlock>, + storage_liveness: ResultsCursor<'a, 'tcx, MaybeStorageLive>, + place_cache: Vec<PlaceRef<'tcx>>, + value_cache: Vec<u128>, +} + +impl<'a, 'tcx> TypeChecker<'a, 'tcx> { + fn fail(&self, location: Location, msg: impl AsRef<str>) { + let span = self.body.source_info(location).span; + // We use `delay_span_bug` as we might see broken MIR when other errors have already + // occurred. + self.tcx.sess.diagnostic().delay_span_bug( + span, + &format!( + "broken MIR in {:?} ({}) at {:?}:\n{}", + self.body.source.instance, + self.when, + location, + msg.as_ref() + ), + ); + } + + fn check_edge(&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) + // Non-cleanup blocks can jump to cleanup blocks along unwind edges + | (false, true, EdgeKind::Unwind) + // Cleanup blocks can jump to cleanup blocks along non-unwind edges + | (true, true, EdgeKind::Normal) => {} + // 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)) + } + } + + /// 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; + } + // Normalization reveals opaque types, but we may be validating MIR while computing + // said opaque types, causing cycles. + if (src, dest).has_opaque_types() { + return true; + } + // Normalize projections and things like that. + let param_env = self.param_env.with_reveal_all_normalized(self.tcx); + let src = self.tcx.normalize_erasing_regions(param_env, src); + let dest = self.tcx.normalize_erasing_regions(param_env, dest); + + // Type-changing assignments can happen when subtyping is used. While + // all normal lifetimes are erased, higher-ranked types with their + // late-bound lifetimes are still around and can lead to type + // differences. So we compare ignoring lifetimes. + equal_up_to_regions(self.tcx, param_env, src, dest) + } +} + +impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'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 {:?} has no corresponding declaration in `body.local_decls`", local), + ); + } + + if self.reachable_blocks.contains(location.block) && context.is_use() { + // We check that the local is live whenever it is used. Technically, violating this + // restriction is only UB and not actually indicative of not well-formed MIR. This means + // that an optimization which turns MIR that already has UB into MIR that fails this + // check is not necessarily wrong. However, we have no such optimizations at the moment, + // and so we include this check anyway to help us catch bugs. If you happen to write an + // optimization that might cause this to incorrectly fire, feel free to remove this + // check. + self.storage_liveness.seek_after_primary_effect(location); + let locals_with_storage = self.storage_liveness.get(); + if !locals_with_storage.contains(local) { + self.fail(location, format!("use of local {:?}, which has no storage here", local)); + } + } + } + + 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::DropsLowered + { + // `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; + let span = self.body.source_info(location).span; + + if !ty.is_copy_modulo_regions(self.tcx.at(span), 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, + local: Local, + proj_base: &[PlaceElem<'tcx>], + elem: PlaceElem<'tcx>, + context: PlaceContext, + location: Location, + ) { + match elem { + 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 ({:?} != usize)", index_ty)) + } + } + ProjectionElem::Deref if self.mir_phase >= MirPhase::GeneratorsLowered => { + let base_ty = Place::ty_from(local, proj_base, &self.body.local_decls, self.tcx).ty; + + if base_ty.is_box() { + self.fail( + location, + format!("{:?} dereferenced after ElaborateBoxDerefs", base_ty), + ) + } + } + ProjectionElem::Field(f, ty) => { + let parent = Place { local, projection: self.tcx.intern_place_elems(proj_base) }; + let parent_ty = parent.ty(&self.body.local_decls, self.tcx); + let fail_out_of_bounds = |this: &Self, location| { + this.fail(location, format!("Out of bounds field {:?} for {:?}", f, parent_ty)); + }; + let check_equal = |this: &Self, location, f_ty| { + if !this.mir_assign_valid_types(ty, f_ty) { + this.fail( + location, + format!( + "Field projection `{:?}.{:?}` specified type `{:?}`, but actual type is {:?}", + parent, f, ty, f_ty + ) + ) + } + }; + + let kind = match parent_ty.ty.kind() { + &ty::Opaque(def_id, substs) => { + self.tcx.bound_type_of(def_id).subst(self.tcx, substs).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, substs) => { + let var = parent_ty.variant_index.unwrap_or(VariantIdx::from_u32(0)); + let Some(field) = adt_def.variant(var).fields.get(f.as_usize()) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, field.ty(self.tcx, substs)); + } + ty::Closure(_, substs) => { + let substs = substs.as_closure(); + let Some(f_ty) = substs.upvar_tys().nth(f.as_usize()) else { + fail_out_of_bounds(self, location); + return; + }; + check_equal(self, location, f_ty); + } + &ty::Generator(def_id, substs, _) => { + let f_ty = if let Some(var) = parent_ty.variant_index { + let gen_body = if def_id == self.body.source.def_id() { + self.body + } else { + self.tcx.optimized_mir(def_id) + }; + + let Some(layout) = gen_body.generator_layout() else { + self.fail(location, format!("No generator 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 {:?} for {:?}", local, parent_ty)); + return; + }; + + f_ty + } else { + let Some(f_ty) = substs.as_generator().prefix_tys().nth(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)); + } + } + } + _ => {} + } + self.super_projection_elem(local, proj_base, elem, context, location); + } + + 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::Derefered + && place.projection.len() > 1 + && cntxt != PlaceContext::NonUse(VarDebugInfo) + && place.projection[1..].contains(&ProjectionElem::Deref) + { + self.fail(location, format!("{:?}, has deref at the wrong place", 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, $($patterns:tt)*) => { + if !matches!(($t).kind(), $($patterns)*) { + self.fail(location, format!($text, $t)); + } + }; + } + match rvalue { + Rvalue::Use(_) | Rvalue::CopyForDeref(_) => {} + Rvalue::Aggregate(agg_kind, _) => { + let disallowed = match **agg_kind { + AggregateKind::Array(..) => false, + AggregateKind::Generator(..) => self.mir_phase >= MirPhase::GeneratorsLowered, + _ => self.mir_phase >= MirPhase::Deaggregated, + }; + if disallowed { + self.fail( + location, + format!("{:?} have been lowered to field assignments", rvalue), + ) + } + } + Rvalue::Ref(_, BorrowKind::Shallow, _) => { + if self.mir_phase >= MirPhase::DropsLowered { + self.fail( + location, + "`Assign` statement with a `Shallow` borrow should have been removed after drop lowering phase", + ); + } + } + 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); + 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 compare type {:?}", + ty::Bool + | ty::Char + | ty::Int(..) + | ty::Uint(..) + | ty::Float(..) + | ty::RawPtr(..) + | ty::FnPtr(..) + ) + } + // The function pointer types can have lifetimes + if !self.mir_assign_valid_types(a, b) { + self.fail( + location, + format!("Cannot compare unequal types {:?} and {:?}", a, b), + ); + } + } + Shl | Shr => { + for x in [a, b] { + check_kinds!( + x, + "Cannot shift non-integer type {:?}", + ty::Uint(..) | ty::Int(..) + ) + } + } + BitAnd | BitOr | BitXor => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform bitwise op on type {:?}", + ty::Uint(..) | ty::Int(..) | ty::Bool + ) + } + if a != b { + self.fail( + location, + format!( + "Cannot perform bitwise op on unequal types {:?} and {:?}", + a, b + ), + ); + } + } + Add | Sub | Mul | Div | Rem => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform arithmetic on type {:?}", + ty::Uint(..) | ty::Int(..) | ty::Float(..) + ) + } + if a != b { + self.fail( + location, + format!( + "Cannot perform arithmetic on unequal types {:?} and {:?}", + a, b + ), + ); + } + } + } + } + Rvalue::CheckedBinaryOp(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); + match op { + Add | Sub | Mul => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform checked arithmetic on type {:?}", + ty::Uint(..) | ty::Int(..) + ) + } + if a != b { + self.fail( + location, + format!( + "Cannot perform checked arithmetic on unequal types {:?} and {:?}", + a, b + ), + ); + } + } + Shl | Shr => { + for x in [a, b] { + check_kinds!( + x, + "Cannot perform checked shift on non-integer type {:?}", + ty::Uint(..) | ty::Int(..) + ) + } + } + _ => self.fail(location, format!("There is no checked version of {:?}", op)), + } + } + 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) => { + match kind { + CastKind::Misc => { + let op_ty = operand.ty(self.body, self.tcx); + if op_ty.is_enum() { + self.fail( + location, + format!( + "enum -> int casts should go through `Rvalue::Discriminant`: {operand:?}:{op_ty} as {target_type}", + ), + ); + } + } + // Nothing to check here + CastKind::PointerFromExposedAddress + | CastKind::PointerExposeAddress + | CastKind::Pointer(_) => {} + } + } + Rvalue::Repeat(_, _) + | Rvalue::ThreadLocalRef(_) + | Rvalue::AddressOf(_, _) + | Rvalue::NullaryOp(_, _) + | 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_some() + { + self.fail( + location, + "`CopyForDeref` should only be used for dereferenceable types", + ) + } + } + // FIXME(JakobDegen): Check this for all rvalues, not just this one. + if let Rvalue::Use(Operand::Copy(src) | Operand::Move(src)) = rvalue { + // The sides of an assignment must not alias. Currently this just checks whether + // the places are identical. + if dest == src { + self.fail( + location, + "encountered `Assign` statement with overlapping memory", + ); + } + } + } + StatementKind::AscribeUserType(..) => { + if self.mir_phase >= MirPhase::DropsLowered { + self.fail( + location, + "`AscribeUserType` should have been removed after drop lowering phase", + ); + } + } + StatementKind::FakeRead(..) => { + if self.mir_phase >= MirPhase::DropsLowered { + self.fail( + location, + "`FakeRead` should have been removed after drop lowering phase", + ); + } + } + StatementKind::CopyNonOverlapping(box rustc_middle::mir::CopyNonOverlapping { + ref src, + ref dst, + ref 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.ty + } 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.ty + } 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 ({:?} != usize)", op_cnt_ty)) + } + } + StatementKind::SetDiscriminant { place, .. } => { + if self.mir_phase < MirPhase::Deaggregated { + 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::Generator(..) | ty::Opaque(..)) { + self.fail( + location, + format!( + "`SetDiscriminant` is only allowed on ADTs and generators, not {:?}", + pty + ), + ); + } + } + StatementKind::Deinit(..) => { + if self.mir_phase < MirPhase::Deaggregated { + self.fail(location, "`Deinit`is not allowed until deaggregation"); + } + } + StatementKind::Retag(_, _) => { + // 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. + } + StatementKind::StorageLive(..) + | StatementKind::StorageDead(..) + | StatementKind::Coverage(_) + | 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, switch_ty, discr } => { + let ty = discr.ty(&self.body.local_decls, self.tcx); + if ty != *switch_ty { + self.fail( + location, + format!( + "encountered `SwitchInt` terminator with type mismatch: {:?} != {:?}", + ty, switch_ty, + ), + ); + } + + 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, target) in targets.iter() { + if Scalar::<()>::try_from_uint(value, size).is_none() { + self.fail( + location, + format!("the value {:#x} is not a proper {:?}", value, switch_ty), + ) + } + + 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 all_len = self.value_cache.len(); + self.value_cache.sort_unstable(); + self.value_cache.dedup(); + let has_duplicates = all_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); + if let Some(unwind) = unwind { + self.check_edge(location, *unwind, EdgeKind::Unwind); + } + } + TerminatorKind::DropAndReplace { target, unwind, .. } => { + if self.mir_phase >= MirPhase::DropsLowered { + self.fail( + location, + "`DropAndReplace` should have been removed during drop elaboration", + ); + } + self.check_edge(location, *target, EdgeKind::Normal); + if let Some(unwind) = unwind { + self.check_edge(location, *unwind, EdgeKind::Unwind); + } + } + TerminatorKind::Call { func, args, destination, target, cleanup, .. } => { + 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 {} in `Call` terminator", func_ty), + ), + } + if let Some(target) = target { + self.check_edge(location, *target, EdgeKind::Normal); + } + if let Some(cleanup) = cleanup { + self.check_edge(location, *cleanup, EdgeKind::Unwind); + } + + // The call destination place and Operand::Move place used as an argument might be + // passed by a reference to the callee. Consequently they must be non-overlapping. + // Currently this simply checks for duplicate places. + self.place_cache.clear(); + self.place_cache.push(destination.as_ref()); + for arg in args { + if let Operand::Move(place) = arg { + self.place_cache.push(place.as_ref()); + } + } + let all_len = self.place_cache.len(); + let mut dedup = FxHashSet::default(); + self.place_cache.retain(|p| dedup.insert(*p)); + let has_duplicates = all_len != self.place_cache.len(); + if has_duplicates { + self.fail( + location, + format!( + "encountered overlapping memory in `Call` terminator: {:?}", + terminator.kind, + ), + ); + } + } + TerminatorKind::Assert { cond, target, cleanup, .. } => { + 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 {} in `Assert` terminator", + cond_ty + ), + ); + } + self.check_edge(location, *target, EdgeKind::Normal); + if let Some(cleanup) = cleanup { + self.check_edge(location, *cleanup, EdgeKind::Unwind); + } + } + TerminatorKind::Yield { resume, drop, .. } => { + if self.body.generator.is_none() { + self.fail(location, "`Yield` cannot appear outside generator bodies"); + } + if self.mir_phase >= MirPhase::GeneratorsLowered { + self.fail(location, "`Yield` should have been replaced by generator 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::DropsLowered { + 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::DropsLowered { + self.fail( + location, + "`FalseUnwind` should have been removed after drop elaboration", + ); + } + self.check_edge(location, *real_target, EdgeKind::Normal); + if let Some(unwind) = unwind { + self.check_edge(location, *unwind, EdgeKind::Unwind); + } + } + TerminatorKind::InlineAsm { destination, cleanup, .. } => { + if let Some(destination) = destination { + self.check_edge(location, *destination, EdgeKind::Normal); + } + if let Some(cleanup) = cleanup { + self.check_edge(location, *cleanup, EdgeKind::Unwind); + } + } + TerminatorKind::GeneratorDrop => { + if self.body.generator.is_none() { + self.fail(location, "`GeneratorDrop` cannot appear outside generator bodies"); + } + if self.mir_phase >= MirPhase::GeneratorsLowered { + self.fail( + location, + "`GeneratorDrop` should have been replaced by generator lowering", + ); + } + } + TerminatorKind::Resume | TerminatorKind::Abort => { + let bb = location.block; + if !self.body.basic_blocks()[bb].is_cleanup { + self.fail(location, "Cannot `Resume` or `Abort` 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.sess.diagnostic().delay_span_bug( + self.body.span, + &format!( + "broken MIR in {:?} ({}):\ninvalid source scope {:?}", + self.body.source.instance, self.when, scope, + ), + ); + } + } +} |