bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

fix name resolution for param defaults

Browse source
This commit is contained in:
lcnr 2021-04-18 13:57:22 +02:00
parent d7c3386414
commit 259a368e9e
15 changed files with 141 additions and 104 deletions
Download patch file Download diff file Expand all files Collapse all files

11
compiler/rustc_resolve/src/diagnostics.rs
View file

@ -472,17 +472,6 @@ impl<'a> Resolver<'a> {
);
err
}
ResolutionError::ParamInAnonConstInTyDefault(name) => {
let mut err = self.session.struct_span_err(
span,
"constant values inside of type parameter defaults must not depend on generic parameters",
);
err.span_label(
span,
format!("the anonymous constant must not depend on the parameter `{}`", name),
);
err
}
ResolutionError::ParamInNonTrivialAnonConst { name, is_type } => {
let mut err = self.session.struct_span_err(
span,

69
compiler/rustc_resolve/src/late.rs
View file

@ -555,18 +555,23 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
// provide previous type parameters as they're built. We
// put all the parameters on the ban list and then remove
// them one by one as they are processed and become available.
let mut default_ban_rib = Rib::new(ForwardGenericParamBanRibKind);
let mut found_default = false;
default_ban_rib.bindings.extend(generics.params.iter().filter_map(
|param| match param.kind {
GenericParamKind::Type { default: Some(_), .. }
| GenericParamKind::Const { default: Some(_), .. } => {
found_default = true;
Some((Ident::with_dummy_span(param.ident.name), Res::Err))
let mut forward_ty_ban_rib = Rib::new(ForwardGenericParamBanRibKind);
let mut forward_const_ban_rib = Rib::new(ForwardGenericParamBanRibKind);
for param in generics.params.iter() {
match param.kind {
GenericParamKind::Type { .. } => {
forward_ty_ban_rib
.bindings
.insert(Ident::with_dummy_span(param.ident.name), Res::Err);
}
_ => None,
},
));
GenericParamKind::Const { .. } => {
forward_const_ban_rib
.bindings
.insert(Ident::with_dummy_span(param.ident.name), Res::Err);
}
GenericParamKind::Lifetime => {}
}
}
// rust-lang/rust#61631: The type `Self` is essentially
// another type parameter. For ADTs, we consider it
@ -579,7 +584,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
// such as in the case of `trait Add<Rhs = Self>`.)
if self.diagnostic_metadata.current_self_item.is_some() {
// (`Some` if + only if we are in ADT's generics.)
default_ban_rib.bindings.insert(Ident::with_dummy_span(kw::SelfUpper), Res::Err);
forward_ty_ban_rib.bindings.insert(Ident::with_dummy_span(kw::SelfUpper), Res::Err);
}
for param in &generics.params {
@ -591,32 +596,38 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
}
if let Some(ref ty) = default {
self.ribs[TypeNS].push(default_ban_rib);
self.with_rib(ValueNS, ForwardGenericParamBanRibKind, |this| {
// HACK: We use an empty `ForwardGenericParamBanRibKind` here which
// is only used to forbid the use of const parameters inside of
// type defaults.
//
// While the rib name doesn't really fit here, it does allow us to use the same
// code for both const and type parameters.
this.visit_ty(ty);
});
default_ban_rib = self.ribs[TypeNS].pop().unwrap();
self.ribs[TypeNS].push(forward_ty_ban_rib);
self.ribs[ValueNS].push(forward_const_ban_rib);
self.visit_ty(ty);
forward_const_ban_rib = self.ribs[ValueNS].pop().unwrap();
forward_ty_ban_rib = self.ribs[TypeNS].pop().unwrap();
}
// Allow all following defaults to refer to this type parameter.
default_ban_rib.bindings.remove(&Ident::with_dummy_span(param.ident.name));
forward_ty_ban_rib.bindings.remove(&Ident::with_dummy_span(param.ident.name));
}
GenericParamKind::Const { ref ty, kw_span: _, default: _ } => {
// FIXME(const_generics_defaults): handle `default` value here
for bound in &param.bounds {
self.visit_param_bound(bound);
}
GenericParamKind::Const { ref ty, kw_span: _, ref default } => {
// Const parameters can't have param bounds.
assert!(param.bounds.is_empty());
self.ribs[TypeNS].push(Rib::new(ConstParamTyRibKind));
self.ribs[ValueNS].push(Rib::new(ConstParamTyRibKind));
self.visit_ty(ty);
self.ribs[TypeNS].pop().unwrap();
self.ribs[ValueNS].pop().unwrap();
if let Some(ref expr) = default {
self.ribs[TypeNS].push(forward_ty_ban_rib);
self.ribs[ValueNS].push(forward_const_ban_rib);
self.visit_anon_const(expr);
forward_const_ban_rib = self.ribs[ValueNS].pop().unwrap();
forward_ty_ban_rib = self.ribs[TypeNS].pop().unwrap();
}
// Allow all following defaults to refer to this const parameter.
forward_const_ban_rib
.bindings
.remove(&Ident::with_dummy_span(param.ident.name));
}
}
}

56
compiler/rustc_resolve/src/lib.rs
View file

@ -239,8 +239,6 @@ enum ResolutionError<'a> {
ForwardDeclaredTyParam, // FIXME(const_generics_defaults)
/// ERROR E0770: the type of const parameters must not depend on other generic parameters.
ParamInTyOfConstParam(Symbol),
/// constant values inside of type parameter defaults must not depend on generic parameters.
ParamInAnonConstInTyDefault(Symbol),
/// generic parameters must not be used inside const evaluations.
///
/// This error is only emitted when using `min_const_generics`.
@ -2672,26 +2670,18 @@ impl<'a> Resolver<'a> {
}
}
Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => {
let mut in_ty_param_default = false;
for rib in ribs {
let has_generic_params = match rib.kind {
let has_generic_params: HasGenericParams = match rib.kind {
NormalRibKind
| ClosureOrAsyncRibKind
| AssocItemRibKind
| ModuleRibKind(..)
| MacroDefinition(..) => {
| MacroDefinition(..)
| ForwardGenericParamBanRibKind => {
// Nothing to do. Continue.
continue;
}
// We only forbid constant items if we are inside of type defaults,
// for example `struct Foo<T, U = [u8; std::mem::size_of::<T>()]>`
ForwardGenericParamBanRibKind => {
// FIXME(const_generic_defaults): we may need to distinguish between
// being in type parameter defaults and const parameter defaults
in_ty_param_default = true;
continue;
}
ConstantItemRibKind(trivial, _) => {
let features = self.session.features_untracked();
// HACK(min_const_generics): We currently only allow `N` or `{ N }`.
@ -2720,19 +2710,7 @@ impl<'a> Resolver<'a> {
}
}
if in_ty_param_default {
if record_used {
self.report_error(
span,
ResolutionError::ParamInAnonConstInTyDefault(
rib_ident.name,
),
);
}
return Res::Err;
} else {
continue;
}
continue;
}
// This was an attempt to use a type parameter outside its scope.
@ -2770,23 +2748,15 @@ impl<'a> Resolver<'a> {
ribs.next();
}
let mut in_ty_param_default = false;
for rib in ribs {
let has_generic_params = match rib.kind {
NormalRibKind
| ClosureOrAsyncRibKind
| AssocItemRibKind
| ModuleRibKind(..)
| MacroDefinition(..) => continue,
| MacroDefinition(..)
| ForwardGenericParamBanRibKind => continue,
// We only forbid constant items if we are inside of type defaults,
// for example `struct Foo<T, U = [u8; std::mem::size_of::<T>()]>`
ForwardGenericParamBanRibKind => {
// FIXME(const_generic_defaults): we may need to distinguish between
// being in type parameter defaults and const parameter defaults
in_ty_param_default = true;
continue;
}
ConstantItemRibKind(trivial, _) => {
let features = self.session.features_untracked();
// HACK(min_const_generics): We currently only allow `N` or `{ N }`.
@ -2808,19 +2778,7 @@ impl<'a> Resolver<'a> {
return Res::Err;
}
if in_ty_param_default {
if record_used {
self.report_error(
span,
ResolutionError::ParamInAnonConstInTyDefault(
rib_ident.name,
),
);
}
return Res::Err;
} else {
continue;
}
continue;
}
ItemRibKind(has_generic_params) => has_generic_params,