bjoernager/rust
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Relate identical parameters in array lengths

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This commit is contained in:
varkor 2019-05-11 18:01:50 +01:00
parent 7212685837
commit 73f7e426be
1 changed files with 17 additions and 21 deletions
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38
src/librustc/ty/relate.rs
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@ -9,7 +9,6 @@ use crate::ty::subst::{Kind, UnpackedKind, SubstsRef};
use crate::ty::{self, Ty, TyCtxt, TypeFoldable}; use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
use crate::ty::error::{ExpectedFound, TypeError}; use crate::ty::error::{ExpectedFound, TypeError};
use crate::mir::interpret::{GlobalId, ConstValue, Scalar}; use crate::mir::interpret::{GlobalId, ConstValue, Scalar};
use crate::util::common::ErrorReported;
use syntax_pos::DUMMY_SP; use syntax_pos::DUMMY_SP;
use std::rc::Rc; use std::rc::Rc;
use std::iter; use std::iter;
@ -474,8 +473,9 @@ pub fn super_relate_tys<'a, 'gcx, 'tcx, R>(relation: &mut R,
(&ty::Array(a_t, sz_a), &ty::Array(b_t, sz_b)) => (&ty::Array(a_t, sz_a), &ty::Array(b_t, sz_b)) =>
{ {
let t = relation.relate(&a_t, &b_t)?; let t = relation.relate(&a_t, &b_t)?;
let to_u64 = |x: ty::Const<'tcx>| -> Result<u64, ErrorReported> {
match x.val { let to_u64 = |ct: &'tcx ty::Const<'tcx>| -> Option<u64> {
match ct.val {
// FIXME(const_generics): this doesn't work right now, // FIXME(const_generics): this doesn't work right now,
// because it tries to relate an `Infer` to a `Param`. // because it tries to relate an `Infer` to a `Param`.
ConstValue::Unevaluated(def_id, substs) => { ConstValue::Unevaluated(def_id, substs) => {
@ -493,26 +493,18 @@ pub fn super_relate_tys<'a, 'gcx, 'tcx, R>(relation: &mut R,
instance, instance,
promoted: None, promoted: None,
}; };
if let Some(s) = tcx.const_eval(param_env.and(cid)) return tcx.const_eval(param_env.and(cid))
.ok() .ok()
.map(|c| c.unwrap_usize(tcx)) { .map(|c| c.unwrap_usize(tcx));
return Ok(s)
}
} }
} }
tcx.sess.delay_span_bug(tcx.def_span(def_id), None
"array length could not be evaluated");
Err(ErrorReported)
} }
_ => x.assert_usize(tcx).ok_or_else(|| { _ => ct.assert_usize(tcx),
tcx.sess.delay_span_bug(DUMMY_SP,
"array length could not be evaluated");
ErrorReported
})
} }
}; };
match (to_u64(*sz_a), to_u64(*sz_b)) { match (to_u64(sz_a), to_u64(sz_b)) {
(Ok(sz_a_u64), Ok(sz_b_u64)) => { (Some(sz_a_u64), Some(sz_b_u64)) => {
if sz_a_u64 == sz_b_u64 { if sz_a_u64 == sz_b_u64 {
Ok(tcx.mk_ty(ty::Array(t, sz_a))) Ok(tcx.mk_ty(ty::Array(t, sz_a)))
} else { } else {
@ -520,9 +512,13 @@ pub fn super_relate_tys<'a, 'gcx, 'tcx, R>(relation: &mut R,
expected_found(relation, &sz_a_u64, &sz_b_u64))) expected_found(relation, &sz_a_u64, &sz_b_u64)))
} }
} }
// We reported an error or will ICE, so we can return Error. _ => {
(Err(ErrorReported), _) | (_, Err(ErrorReported)) => { if let Ok(sz) = relation.relate(&sz_a, &sz_b) {
Ok(tcx.types.err) Ok(tcx.mk_ty(ty::Array(t, sz)))
} else {
tcx.sess.delay_span_bug(DUMMY_SP, "array length could not be evaluated");
Ok(tcx.types.err)
}
} }
} }
} }