Skip to content

Sema: Diagnose references to protocol extension type aliases from generic requirements #60984

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Sep 8, 2022
Merged

Sema: Diagnose references to protocol extension type aliases from generic requirements #60984

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 9 additions & 0 deletions include/swift/AST/DiagnosticsSema.def
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -865,6 +865,15 @@ NOTE(invalid_redecl_implicit_wrapper,none,
"%select{projected value|backing storage}1",
(DeclName, bool))

ERROR(protocol_extension_in_where_clause,none,
"%0 was defined in extension of protocol %1 and cannot be referenced "
"from a %select{'where' clause|generic parameter inheritance clause|"
"associated type inheritance clause}2",
(Identifier, Identifier, unsigned))
NOTE(protocol_extension_in_where_clause_note,none,
"consider moving %0 into the definition of protocol %1",
(Identifier, Identifier))

ERROR(ambiguous_type_base,none,
"%0 is ambiguous for type lookup in this context", (DeclNameRef))
ERROR(invalid_member_type,none,
Expand Down
14 changes: 12 additions & 2 deletions lib/Sema/TypeCheckRequestFunctions.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,28 +31,38 @@ Type InheritedTypeRequest::evaluate(
unsigned index, TypeResolutionStage stage) const {
// Figure out how to resolve types.
DeclContext *dc;
TypeResolverContext context;

if (auto typeDecl = decl.dyn_cast<const TypeDecl *>()) {
if (auto nominal = dyn_cast<NominalTypeDecl>(typeDecl)) {
dc = (DeclContext *)nominal;
context = TypeResolverContext::Inherited;
} else {
dc = typeDecl->getDeclContext();
if (isa<GenericTypeParamDecl>(typeDecl))
context = TypeResolverContext::GenericParameterInherited;
else {
assert(isa<AssociatedTypeDecl>(typeDecl));
context = TypeResolverContext::AssociatedTypeInherited;
}
}
} else {
dc = (DeclContext *)decl.get<const ExtensionDecl *>();
context = TypeResolverContext::Inherited;
}

Optional<TypeResolution> resolution;
switch (stage) {
case TypeResolutionStage::Structural:
resolution =
TypeResolution::forStructural(dc, TypeResolverContext::Inherited,
TypeResolution::forStructural(dc, context,
/*unboundTyOpener*/ nullptr,
/*placeholderHandler*/ nullptr);
break;

case TypeResolutionStage::Interface:
resolution =
TypeResolution::forInterface(dc, TypeResolverContext::Inherited,
TypeResolution::forInterface(dc, context,
/*unboundTyOpener*/ nullptr,
/*placeholderHandler*/ nullptr);
break;
Expand Down
65 changes: 65 additions & 0 deletions lib/Sema/TypeCheckType.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -119,6 +119,51 @@ static DescriptiveDeclKind describeDeclOfType(Type t) {
return DescriptiveDeclKind::Type;
}

static unsigned getGenericRequirementKind(TypeResolutionOptions options) {
switch (options.getBaseContext()) {
case TypeResolverContext::GenericRequirement:
case TypeResolverContext::SameTypeRequirement:
return 0;

case TypeResolverContext::GenericParameterInherited:
return 1;

case TypeResolverContext::AssociatedTypeInherited:
return 2;

case TypeResolverContext::None:
case TypeResolverContext::Inherited:
case TypeResolverContext::FunctionInput:
case TypeResolverContext::TupleElement:
case TypeResolverContext::GenericArgument:
case TypeResolverContext::ProtocolGenericArgument:
case TypeResolverContext::ExtensionBinding:
case TypeResolverContext::TypeAliasDecl:
case TypeResolverContext::GenericTypeAliasDecl:
case TypeResolverContext::ExistentialConstraint:
case TypeResolverContext::MetatypeBase:
case TypeResolverContext::InExpression:
case TypeResolverContext::ExplicitCastExpr:
case TypeResolverContext::ForEachStmt:
case TypeResolverContext::PatternBindingDecl:
case TypeResolverContext::EditorPlaceholderExpr:
case TypeResolverContext::ClosureExpr:
case TypeResolverContext::VariadicFunctionInput:
case TypeResolverContext::InoutFunctionInput:
case TypeResolverContext::FunctionResult:
case TypeResolverContext::SubscriptDecl:
case TypeResolverContext::EnumElementDecl:
case TypeResolverContext::EnumPatternPayload:
case TypeResolverContext::ProtocolMetatypeBase:
case TypeResolverContext::ImmediateOptionalTypeArgument:
case TypeResolverContext::AbstractFunctionDecl:
case TypeResolverContext::CustomAttr:
break;
}

llvm_unreachable("Invalid type resolution context");
}

Type TypeResolution::resolveDependentMemberType(
Type baseTy, DeclContext *DC,
SourceRange baseRange,
Expand All @@ -144,6 +189,24 @@ Type TypeResolution::resolveDependentMemberType(

// Look for a nested type with the given name.
if (auto nestedType = genericSig->lookupNestedType(baseTy, refIdentifier)) {
if (options.isGenericRequirement()) {
if (auto *protoDecl = nestedType->getDeclContext()->getExtendedProtocolDecl()) {
if (!options.contains(TypeResolutionFlags::SilenceErrors)) {
unsigned kind = getGenericRequirementKind(options);
ctx.Diags.diagnose(ref->getNameLoc(),
diag::protocol_extension_in_where_clause,
nestedType->getName(), protoDecl->getName(), kind);
if (protoDecl->getLoc() && nestedType->getLoc()) {
ctx.Diags.diagnose(nestedType->getLoc(),
diag::protocol_extension_in_where_clause_note,
nestedType->getName(), protoDecl->getName());
}
}

return ErrorType::get(ctx);
}
}

// Record the type we found.
ref->setValue(nestedType, nullptr);
} else {
Expand Down Expand Up @@ -3991,6 +4054,8 @@ NeverNullType TypeResolver::resolveImplicitlyUnwrappedOptionalType(
case TypeResolverContext::AbstractFunctionDecl:
case TypeResolverContext::ClosureExpr:
case TypeResolverContext::Inherited:
case TypeResolverContext::GenericParameterInherited:
case TypeResolverContext::AssociatedTypeInherited:
case TypeResolverContext::CustomAttr:
doDiag = true;
break;
Expand Down
55 changes: 54 additions & 1 deletion lib/Sema/TypeCheckType.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -162,9 +162,15 @@ enum class TypeResolverContext : uint8_t {
/// Whether this is the type of an editor placeholder.
EditorPlaceholderExpr,

/// Whether this is an "inherited" type.
/// Whether this is an inheritance clause of a concrete type.
Inherited,

/// Whether this is an inheritance clause of a generic parameter.
GenericParameterInherited,

/// Whether this is an inheritance clause of an associated type.
AssociatedTypeInherited,

/// Whether this is a custom attribute.
CustomAttr
};
Expand Down Expand Up @@ -256,6 +262,8 @@ class TypeResolutionOptions {
case Context::ImmediateOptionalTypeArgument:
case Context::AbstractFunctionDecl:
case Context::Inherited:
case Context::GenericParameterInherited:
case Context::AssociatedTypeInherited:
case Context::CustomAttr:
return false;
}
Expand All @@ -267,6 +275,8 @@ class TypeResolutionOptions {
bool isConstraintImplicitExistential() const {
switch (context) {
case Context::Inherited:
case Context::GenericParameterInherited:
case Context::AssociatedTypeInherited:
case Context::ExtensionBinding:
case Context::TypeAliasDecl:
case Context::GenericTypeAliasDecl:
Expand Down Expand Up @@ -311,6 +321,8 @@ class TypeResolutionOptions {
case Context::None:
case Context::ProtocolGenericArgument:
case Context::Inherited:
case Context::GenericParameterInherited:
case Context::AssociatedTypeInherited:
case Context::ExtensionBinding:
case Context::TypeAliasDecl:
case Context::GenericTypeAliasDecl:
Expand Down Expand Up @@ -338,6 +350,47 @@ class TypeResolutionOptions {
}
}

/// Whether we are resolving a type in a `where` clause, generic parameter
/// declaration inheritance clause, or associated type inheritance clause.
bool isGenericRequirement() const {
switch (base) {
case Context::GenericRequirement:
case Context::SameTypeRequirement:
case Context::GenericParameterInherited:
case Context::AssociatedTypeInherited:
return true;

case Context::None:
case Context::Inherited:
case Context::FunctionInput:
case Context::TupleElement:
case Context::GenericArgument:
case Context::ProtocolGenericArgument:
case Context::ExtensionBinding:
case Context::TypeAliasDecl:
case Context::GenericTypeAliasDecl:
case Context::ExistentialConstraint:
case Context::MetatypeBase:
case Context::InExpression:
case Context::ExplicitCastExpr:
case Context::ForEachStmt:
case Context::PatternBindingDecl:
case Context::EditorPlaceholderExpr:
case Context::ClosureExpr:
case Context::VariadicFunctionInput:
case Context::InoutFunctionInput:
case Context::FunctionResult:
case Context::SubscriptDecl:
case Context::EnumElementDecl:
case Context::EnumPatternPayload:
case Context::ProtocolMetatypeBase:
case Context::ImmediateOptionalTypeArgument:
case Context::AbstractFunctionDecl:
case Context::CustomAttr:
return false;
}
}

/// Determine whether all of the given options are set.
bool contains(TypeResolutionFlags set) const {
return !static_cast<bool>(unsigned(set) & ~unsigned(flags));
Expand Down