diff options
Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_const_eval/src/const_eval/eval_queries.rs | 92 |
1 files changed, 40 insertions, 52 deletions
diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs index 975fb4b22..1b1052fdf 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -2,8 +2,8 @@ use super::{CompileTimeEvalContext, CompileTimeInterpreter, ConstEvalErr}; use crate::interpret::eval_nullary_intrinsic; use crate::interpret::{ intern_const_alloc_recursive, Allocation, ConstAlloc, ConstValue, CtfeValidationMode, GlobalId, - Immediate, InternKind, InterpCx, InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking, - ScalarMaybeUninit, StackPopCleanup, InterpError, + Immediate, InternKind, InterpCx, InterpError, InterpResult, MPlaceTy, MemoryKind, OpTy, + RefTracking, StackPopCleanup, }; use rustc_hir::def::DefKind; @@ -13,7 +13,7 @@ use rustc_middle::mir::pretty::display_allocation; use rustc_middle::traits::Reveal; use rustc_middle::ty::layout::LayoutOf; use rustc_middle::ty::print::with_no_trimmed_paths; -use rustc_middle::ty::{self, subst::Subst, TyCtxt}; +use rustc_middle::ty::{self, TyCtxt}; use rustc_span::source_map::Span; use rustc_target::abi::{self, Abi}; use std::borrow::Cow; @@ -74,14 +74,16 @@ fn eval_body_using_ecx<'mir, 'tcx>( None => InternKind::Constant, } }; + ecx.machine.check_alignment = false; // interning doesn't need to respect alignment intern_const_alloc_recursive(ecx, intern_kind, &ret)?; + // we leave alignment checks off, since this `ecx` will not be used for further evaluation anyway debug!("eval_body_using_ecx done: {:?}", *ret); Ok(ret) } /// The `InterpCx` is only meant to be used to do field and index projections into constants for -/// `simd_shuffle` and const patterns in match arms. +/// `simd_shuffle` and const patterns in match arms. It never performs alignment checks. /// /// The function containing the `match` that is currently being analyzed may have generic bounds /// that inform us about the generic bounds of the constant. E.g., using an associated constant @@ -98,7 +100,11 @@ pub(super) fn mk_eval_cx<'mir, 'tcx>( tcx, root_span, param_env, - CompileTimeInterpreter::new(tcx.const_eval_limit(), can_access_statics), + CompileTimeInterpreter::new( + tcx.const_eval_limit(), + can_access_statics, + /*check_alignment:*/ false, + ), ) } @@ -166,10 +172,7 @@ pub(super) fn op_to_const<'tcx>( // see comment on `let try_as_immediate` above Err(imm) => match *imm { _ if imm.layout.is_zst() => ConstValue::ZeroSized, - Immediate::Scalar(x) => match x { - ScalarMaybeUninit::Scalar(s) => ConstValue::Scalar(s), - ScalarMaybeUninit::Uninit => to_const_value(&op.assert_mem_place()), - }, + Immediate::Scalar(x) => ConstValue::Scalar(x), Immediate::ScalarPair(a, b) => { debug!("ScalarPair(a: {:?}, b: {:?})", a, b); // We know `offset` is relative to the allocation, so we can use `into_parts`. @@ -194,7 +197,7 @@ pub(super) fn op_to_const<'tcx>( } } -#[instrument(skip(tcx), level = "debug")] +#[instrument(skip(tcx), level = "debug", ret)] pub(crate) fn turn_into_const_value<'tcx>( tcx: TyCtxt<'tcx>, constant: ConstAlloc<'tcx>, @@ -203,7 +206,13 @@ pub(crate) fn turn_into_const_value<'tcx>( let cid = key.value; let def_id = cid.instance.def.def_id(); let is_static = tcx.is_static(def_id); - let ecx = mk_eval_cx(tcx, tcx.def_span(key.value.instance.def_id()), key.param_env, is_static); + // This is just accessing an already computed constant, so no need to check alginment here. + let ecx = mk_eval_cx( + tcx, + tcx.def_span(key.value.instance.def_id()), + key.param_env, + /*can_access_statics:*/ is_static, + ); let mplace = ecx.raw_const_to_mplace(constant).expect( "can only fail if layout computation failed, \ @@ -215,10 +224,7 @@ pub(crate) fn turn_into_const_value<'tcx>( ); // Turn this into a proper constant. - let const_val = op_to_const(&ecx, &mplace.into()); - debug!(?const_val); - - const_val + op_to_const(&ecx, &mplace.into()) } #[instrument(skip(tcx), level = "debug")] @@ -300,52 +306,34 @@ pub fn eval_to_allocation_raw_provider<'tcx>( key.param_env, // Statics (and promoteds inside statics) may access other statics, because unlike consts // they do not have to behave "as if" they were evaluated at runtime. - CompileTimeInterpreter::new(tcx.const_eval_limit(), /*can_access_statics:*/ is_static), + CompileTimeInterpreter::new( + tcx.const_eval_limit(), + /*can_access_statics:*/ is_static, + /*check_alignment:*/ tcx.sess.opts.unstable_opts.extra_const_ub_checks, + ), ); let res = ecx.load_mir(cid.instance.def, cid.promoted); match res.and_then(|body| eval_body_using_ecx(&mut ecx, cid, &body)) { Err(error) => { let err = ConstEvalErr::new(&ecx, error, None); - // Some CTFE errors raise just a lint, not a hard error; see - // <https://github.com/rust-lang/rust/issues/71800>. - let is_hard_err = if let Some(def) = def.as_local() { - // (Associated) consts only emit a lint, since they might be unused. - !matches!(tcx.def_kind(def.did.to_def_id()), DefKind::Const | DefKind::AssocConst) - // check if the inner InterpError is hard - || err.error.is_hard_err() + let msg = if is_static { + Cow::from("could not evaluate static initializer") } else { - // use of broken constant from other crate: always an error - true - }; - - if is_hard_err { - let msg = if is_static { - Cow::from("could not evaluate static initializer") + // If the current item has generics, we'd like to enrich the message with the + // instance and its substs: to show the actual compile-time values, in addition to + // the expression, leading to the const eval error. + let instance = &key.value.instance; + if !instance.substs.is_empty() { + let instance = with_no_trimmed_paths!(instance.to_string()); + let msg = format!("evaluation of `{}` failed", instance); + Cow::from(msg) } else { - // If the current item has generics, we'd like to enrich the message with the - // instance and its substs: to show the actual compile-time values, in addition to - // the expression, leading to the const eval error. - let instance = &key.value.instance; - if !instance.substs.is_empty() { - let instance = with_no_trimmed_paths!(instance.to_string()); - let msg = format!("evaluation of `{}` failed", instance); - Cow::from(msg) - } else { - Cow::from("evaluation of constant value failed") - } - }; + Cow::from("evaluation of constant value failed") + } + }; - Err(err.report_as_error(ecx.tcx.at(err.span), &msg)) - } else { - let hir_id = tcx.hir().local_def_id_to_hir_id(def.as_local().unwrap().did); - Err(err.report_as_lint( - tcx.at(tcx.def_span(def.did)), - "any use of this value will cause an error", - hir_id, - Some(err.span), - )) - } + Err(err.report_as_error(ecx.tcx.at(err.span), &msg)) } Ok(mplace) => { // Since evaluation had no errors, validate the resulting constant. |