simplify const params diagnostic on stable
This commit is contained in:
Oliver Downard
parent
dd38eea722
commit
3b4589a309
5 changed files with 86 additions and 90 deletions
|
|
@ -816,16 +816,69 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) {
|
|||
hir::GenericParamKind::Const { ty: hir_ty, default: _ } => {
|
||||
let ty = tcx.type_of(tcx.hir().local_def_id(param.hir_id));
|
||||
|
||||
let err_ty_str;
|
||||
let mut is_ptr = true;
|
||||
let err = if tcx.features().adt_const_params {
|
||||
match ty.peel_refs().kind() {
|
||||
if tcx.features().adt_const_params {
|
||||
let err = match ty.peel_refs().kind() {
|
||||
ty::FnPtr(_) => Some("function pointers"),
|
||||
ty::RawPtr(_) => Some("raw pointers"),
|
||||
_ => None,
|
||||
};
|
||||
|
||||
if let Some(unsupported_type) = err {
|
||||
tcx.sess.span_err(
|
||||
hir_ty.span,
|
||||
&format!(
|
||||
"using {} as const generic parameters is forbidden",
|
||||
unsupported_type
|
||||
),
|
||||
);
|
||||
}
|
||||
|
||||
if traits::search_for_structural_match_violation(param.span, tcx, ty).is_some() {
|
||||
// We use the same error code in both branches, because this is really the same
|
||||
// issue: we just special-case the message for type parameters to make it
|
||||
// clearer.
|
||||
if let ty::Param(_) = ty.peel_refs().kind() {
|
||||
// Const parameters may not have type parameters as their types,
|
||||
// because we cannot be sure that the type parameter derives `PartialEq`
|
||||
// and `Eq` (just implementing them is not enough for `structural_match`).
|
||||
struct_span_err!(
|
||||
tcx.sess,
|
||||
hir_ty.span,
|
||||
E0741,
|
||||
"`{}` is not guaranteed to `#[derive(PartialEq, Eq)]`, so may not be \
|
||||
used as the type of a const parameter",
|
||||
ty,
|
||||
)
|
||||
.span_label(
|
||||
hir_ty.span,
|
||||
format!("`{}` may not derive both `PartialEq` and `Eq`", ty),
|
||||
)
|
||||
.note(
|
||||
"it is not currently possible to use a type parameter as the type of a \
|
||||
const parameter",
|
||||
)
|
||||
.emit();
|
||||
} else {
|
||||
struct_span_err!(
|
||||
tcx.sess,
|
||||
hir_ty.span,
|
||||
E0741,
|
||||
"`{}` must be annotated with `#[derive(PartialEq, Eq)]` to be used as \
|
||||
the type of a const parameter",
|
||||
ty,
|
||||
)
|
||||
.span_label(
|
||||
hir_ty.span,
|
||||
format!("`{}` doesn't derive both `PartialEq` and `Eq`", ty),
|
||||
)
|
||||
.emit();
|
||||
}
|
||||
}
|
||||
} else {
|
||||
match ty.kind() {
|
||||
let err_ty_str;
|
||||
let mut is_ptr = true;
|
||||
|
||||
let err = match ty.kind() {
|
||||
ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Error(_) => None,
|
||||
ty::FnPtr(_) => Some("function pointers"),
|
||||
ty::RawPtr(_) => Some("raw pointers"),
|
||||
|
|
@ -834,74 +887,33 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) {
|
|||
err_ty_str = format!("`{}`", ty);
|
||||
Some(err_ty_str.as_str())
|
||||
}
|
||||
}
|
||||
};
|
||||
if let Some(unsupported_type) = err {
|
||||
if is_ptr {
|
||||
tcx.sess.span_err(
|
||||
hir_ty.span,
|
||||
&format!(
|
||||
"using {} as const generic parameters is forbidden",
|
||||
unsupported_type
|
||||
),
|
||||
);
|
||||
} else {
|
||||
let mut err = tcx.sess.struct_span_err(
|
||||
hir_ty.span,
|
||||
&format!(
|
||||
"{} is forbidden as the type of a const generic parameter",
|
||||
unsupported_type
|
||||
),
|
||||
);
|
||||
err.note("the only supported types are integers, `bool` and `char`");
|
||||
if tcx.sess.is_nightly_build() {
|
||||
err.help(
|
||||
};
|
||||
|
||||
if let Some(unsupported_type) = err {
|
||||
if is_ptr {
|
||||
tcx.sess.span_err(
|
||||
hir_ty.span,
|
||||
&format!(
|
||||
"using {} as const generic parameters is forbidden",
|
||||
unsupported_type
|
||||
),
|
||||
);
|
||||
} else {
|
||||
let mut err = tcx.sess.struct_span_err(
|
||||
hir_ty.span,
|
||||
&format!(
|
||||
"{} is forbidden as the type of a const generic parameter",
|
||||
unsupported_type
|
||||
),
|
||||
);
|
||||
err.note("the only supported types are integers, `bool` and `char`");
|
||||
if tcx.sess.is_nightly_build() {
|
||||
err.help(
|
||||
"more complex types are supported with `#![feature(adt_const_params)]`",
|
||||
);
|
||||
}
|
||||
err.emit();
|
||||
}
|
||||
err.emit();
|
||||
}
|
||||
};
|
||||
|
||||
if traits::search_for_structural_match_violation(param.span, tcx, ty).is_some() {
|
||||
// We use the same error code in both branches, because this is really the same
|
||||
// issue: we just special-case the message for type parameters to make it
|
||||
// clearer.
|
||||
if let ty::Param(_) = ty.peel_refs().kind() {
|
||||
// Const parameters may not have type parameters as their types,
|
||||
// because we cannot be sure that the type parameter derives `PartialEq`
|
||||
// and `Eq` (just implementing them is not enough for `structural_match`).
|
||||
struct_span_err!(
|
||||
tcx.sess,
|
||||
hir_ty.span,
|
||||
E0741,
|
||||
"`{}` is not guaranteed to `#[derive(PartialEq, Eq)]`, so may not be \
|
||||
used as the type of a const parameter",
|
||||
ty,
|
||||
)
|
||||
.span_label(
|
||||
hir_ty.span,
|
||||
format!("`{}` may not derive both `PartialEq` and `Eq`", ty),
|
||||
)
|
||||
.note(
|
||||
"it is not currently possible to use a type parameter as the type of a \
|
||||
const parameter",
|
||||
)
|
||||
.emit();
|
||||
} else {
|
||||
struct_span_err!(
|
||||
tcx.sess,
|
||||
hir_ty.span,
|
||||
E0741,
|
||||
"`{}` must be annotated with `#[derive(PartialEq, Eq)]` to be used as \
|
||||
the type of a const parameter",
|
||||
ty,
|
||||
)
|
||||
.span_label(
|
||||
hir_ty.span,
|
||||
format!("`{}` doesn't derive both `PartialEq` and `Eq`", ty),
|
||||
)
|
||||
.emit();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue