bjoernager/rust
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Remove ops::non_const

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This helper function was meant to reduce code duplication between
const-checking pre- and post-drop-elaboration. Most of the functionality
is only relevant for the pre-drop-elaboration pass.
This commit is contained in:
Dylan MacKenzie 2020-09-29 13:17:38 -07:00
parent ce50939952
commit de35c4293d
3 changed files with 55 additions and 58 deletions
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57
compiler/rustc_mir/src/transform/check_consts/validation.rs
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@ -1,6 +1,6 @@
//! The `Visitor` responsible for actually checking a `mir::Body` for invalid operations.
use rustc_errors::struct_span_err;
use rustc_errors::{struct_span_err, Applicability};
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::{self as hir, HirId, LangItem};
use rustc_infer::infer::TyCtxtInferExt;
@ -11,13 +11,13 @@ use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::{
self, adjustment::PointerCast, Instance, InstanceDef, Ty, TyCtxt, TypeAndMut,
};
use rustc_span::{sym, Span};
use rustc_span::{sym, Span, Symbol};
use rustc_trait_selection::traits::error_reporting::InferCtxtExt;
use rustc_trait_selection::traits::{self, TraitEngine};
use std::ops::Deref;
use super::ops::{self, NonConstOp};
use super::ops::{self, NonConstOp, Status};
use super::qualifs::{self, CustomEq, HasMutInterior, NeedsDrop};
use super::resolver::FlowSensitiveAnalysis;
use super::{is_lang_panic_fn, ConstCx, Qualif};
@ -277,8 +277,33 @@ impl Validator<'mir, 'tcx> {
return;
}
let err_emitted = ops::non_const(self.ccx, op, span);
if err_emitted && O::STOPS_CONST_CHECKING {
let gate = match op.status_in_item(self.ccx) {
Status::Allowed => return,
Status::Unstable(gate) if self.tcx.features().enabled(gate) => {
let unstable_in_stable = self.ccx.is_const_stable_const_fn()
&& !super::allow_internal_unstable(self.tcx, self.def_id.to_def_id(), gate);
if unstable_in_stable {
emit_unstable_in_stable_error(self.ccx, span, gate);
}
return;
}
Status::Unstable(gate) => Some(gate),
Status::Forbidden => None,
};
if self.tcx.sess.opts.debugging_opts.unleash_the_miri_inside_of_you {
self.tcx.sess.miri_unleashed_feature(span, gate);
return;
}
let mut err = op.build_error(self.ccx, span);
assert!(err.is_error());
err.emit();
if O::STOPS_CONST_CHECKING {
self.const_checking_stopped = true;
}
}
@ -892,3 +917,25 @@ fn is_async_fn(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
.fn_sig_by_hir_id(hir_id)
.map_or(false, |sig| sig.header.asyncness == hir::IsAsync::Async)
}
fn emit_unstable_in_stable_error(ccx: &ConstCx<'_, '_>, span: Span, gate: Symbol) {
ccx.tcx
.sess
.struct_span_err(
span,
&format!("const-stable function cannot use `#[feature({})]`", gate.as_str()),
)
.span_suggestion(
ccx.body.span,
"if it is not part of the public API, make this function unstably const",
concat!(r#"#[rustc_const_unstable(feature = "...", issue = "...")]"#, '\n').to_owned(),
Applicability::HasPlaceholders,
)
.span_suggestion(
ccx.body.span,
"otherwise `#[allow_internal_unstable]` can be used to bypass stability checks",
format!("#[allow_internal_unstable({})]", gate),
Applicability::MaybeIncorrect,
)
.emit();
}