diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/const_prop_lint.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/const_prop_lint.rs | 66 |
1 files changed, 39 insertions, 27 deletions
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs index c2ea55af4..37e78f4ac 100644 --- a/compiler/rustc_mir_transform/src/const_prop_lint.rs +++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs @@ -6,9 +6,9 @@ use crate::const_prop::ConstPropMachine; use crate::const_prop::ConstPropMode; use crate::MirLint; use rustc_const_eval::const_eval::ConstEvalErr; +use rustc_const_eval::interpret::Immediate; use rustc_const_eval::interpret::{ - self, InterpCx, InterpResult, LocalState, LocalValue, MemoryKind, OpTy, Scalar, - ScalarMaybeUninit, StackPopCleanup, + self, InterpCx, InterpResult, LocalState, LocalValue, MemoryKind, OpTy, Scalar, StackPopCleanup, }; use rustc_hir::def::DefKind; use rustc_hir::HirId; @@ -22,9 +22,7 @@ use rustc_middle::mir::{ }; use rustc_middle::ty::layout::{LayoutError, LayoutOf, LayoutOfHelpers, TyAndLayout}; use rustc_middle::ty::subst::{InternalSubsts, Subst}; -use rustc_middle::ty::{ - self, ConstInt, ConstKind, Instance, ParamEnv, ScalarInt, Ty, TyCtxt, TypeVisitable, -}; +use rustc_middle::ty::{self, ConstInt, Instance, ParamEnv, ScalarInt, Ty, TyCtxt, TypeVisitable}; use rustc_session::lint; use rustc_span::Span; use rustc_target::abi::{HasDataLayout, Size, TargetDataLayout}; @@ -106,7 +104,7 @@ impl<'tcx> MirLint<'tcx> for ConstProp { let dummy_body = &Body::new( body.source, - body.basic_blocks().clone(), + (*body.basic_blocks).clone(), body.source_scopes.clone(), body.local_decls.clone(), Default::default(), @@ -230,7 +228,13 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { fn get_const(&self, place: Place<'tcx>) -> Option<OpTy<'tcx>> { let op = match self.ecx.eval_place_to_op(place, None) { - Ok(op) => op, + Ok(op) => { + if matches!(*op, interpret::Operand::Immediate(Immediate::Uninit)) { + // Make sure nobody accidentally uses this value. + return None; + } + op + } Err(e) => { trace!("get_const failed: {}", e); return None; @@ -239,7 +243,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { // Try to read the local as an immediate so that if it is representable as a scalar, we can // handle it as such, but otherwise, just return the value as is. - Some(match self.ecx.read_immediate_raw(&op, /*force*/ false) { + Some(match self.ecx.read_immediate_raw(&op) { Ok(Ok(imm)) => imm.into(), _ => op, }) @@ -295,18 +299,15 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { let err = ConstEvalErr::new(&self.ecx, error, Some(c.span)); if let Some(lint_root) = self.lint_root(source_info) { let lint_only = match c.literal { - ConstantKind::Ty(ct) => match ct.kind() { + ConstantKind::Ty(ct) => ct.needs_subst(), + ConstantKind::Unevaluated( + ty::Unevaluated { def: _, substs: _, promoted: Some(_) }, + _, + ) => { // Promoteds must lint and not error as the user didn't ask for them - ConstKind::Unevaluated(ty::Unevaluated { - def: _, - substs: _, - promoted: Some(_), - }) => true, - // Out of backwards compatibility we cannot report hard errors in unused - // generic functions using associated constants of the generic parameters. - _ => c.literal.needs_subst(), - }, - ConstantKind::Val(_, ty) => ty.needs_subst(), + true + } + ConstantKind::Unevaluated(..) | ConstantKind::Val(..) => c.needs_subst(), }; if lint_only { // Out of backwards compatibility we cannot report hard errors in unused @@ -401,8 +402,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { let left_ty = left.ty(self.local_decls, self.tcx); let left_size = self.ecx.layout_of(left_ty).ok()?.size; let right_size = r.layout.size; - let r_bits = r.to_scalar().ok(); - let r_bits = r_bits.and_then(|r| r.to_bits(right_size).ok()); + let r_bits = r.to_scalar().to_bits(right_size).ok(); if r_bits.map_or(false, |b| b >= left_size.bits() as u128) { debug!("check_binary_op: reporting assert for {:?}", source_info); self.report_assert_as_lint( @@ -517,6 +517,14 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { if rvalue.needs_subst() { return None; } + if !rvalue + .ty(&self.ecx.frame().body.local_decls, *self.ecx.tcx) + .is_sized(self.ecx.tcx, self.param_env) + { + // the interpreter doesn't support unsized locals (only unsized arguments), + // but rustc does (in a kinda broken way), so we have to skip them here + return None; + } self.use_ecx(source_info, |this| this.ecx.eval_rvalue_into_place(rvalue, place)) } @@ -524,7 +532,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { fn visit_body(&mut self, body: &Body<'tcx>) { - for (bb, data) in body.basic_blocks().iter_enumerated() { + for (bb, data) in body.basic_blocks.iter_enumerated() { self.visit_basic_block_data(bb, data); } } @@ -625,8 +633,12 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { TerminatorKind::Assert { expected, ref msg, ref cond, .. } => { if let Some(ref value) = self.eval_operand(&cond, source_info) { trace!("assertion on {:?} should be {:?}", value, expected); - let expected = ScalarMaybeUninit::from(Scalar::from_bool(*expected)); - let value_const = self.ecx.read_scalar(&value).unwrap(); + let expected = Scalar::from_bool(*expected); + let Ok(value_const) = self.ecx.read_scalar(&value) else { + // FIXME should be used use_ecx rather than a local match... but we have + // quite a few of these read_scalar/read_immediate that need fixing. + return + }; if expected != value_const { enum DbgVal<T> { Val(T), @@ -643,9 +655,9 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { let mut eval_to_int = |op| { // This can be `None` if the lhs wasn't const propagated and we just // triggered the assert on the value of the rhs. - self.eval_operand(op, source_info).map_or(DbgVal::Underscore, |op| { - DbgVal::Val(self.ecx.read_immediate(&op).unwrap().to_const_int()) - }) + self.eval_operand(op, source_info) + .and_then(|op| self.ecx.read_immediate(&op).ok()) + .map_or(DbgVal::Underscore, |op| DbgVal::Val(op.to_const_int())) }; let msg = match msg { AssertKind::DivisionByZero(op) => { |