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[CodeCompletion] Use GenericSignature methods to get 'associatedtype' requirements #29086

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Merged
merged 3 commits into from
Jan 9, 2020
Merged

[CodeCompletion] Use GenericSignature methods to get 'associatedtype' requirements #29086

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e388c4a
[CodeCompletion] Get associatedtype constraints from ProtocolDecl::ge…
rintaro Jan 9, 2020
1dd6fe5
[CodeCompletion] Stop suggesting opaque result type for generic function
rintaro Jan 9, 2020
b9f1e58
[CodeCompletion] Use GenericSignature methods to get associatedtype reqs
rintaro Jan 9, 2020
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4 changes: 2 additions & 2 deletions lib/AST/ASTPrinter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3039,10 +3039,10 @@ void PrintAST::visitSubscriptDecl(SubscriptDecl *decl) {
Printer << " -> ";

TypeLoc elementTy = decl->getElementTypeLoc();
Printer.printDeclResultTypePre(decl, elementTy);
Printer.callPrintStructurePre(PrintStructureKind::FunctionReturnType);
if (!elementTy.getTypeRepr())
elementTy = TypeLoc::withoutLoc(decl->getElementInterfaceType());
Printer.printDeclResultTypePre(decl, elementTy);
Printer.callPrintStructurePre(PrintStructureKind::FunctionReturnType);

// HACK: When printing result types for subscripts with opaque result types,
// always print them using the `some` keyword instead of printing
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68 changes: 47 additions & 21 deletions lib/IDE/CodeCompletion.cpp
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Expand Up @@ -4159,8 +4159,8 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {

/// Return type if the result type if \p VD should be represented as opaque
/// result type.
TypeLoc getOpaqueResultTypeLoc(const ValueDecl *VD, DeclVisibilityKind Reason,
DynamicLookupInfo dynamicLookupInfo) {
Type getOpaqueResultType(const ValueDecl *VD, DeclVisibilityKind Reason,
DynamicLookupInfo dynamicLookupInfo) {
if (Reason !=
DeclVisibilityKind::MemberOfProtocolImplementedByCurrentNominal)
return nullptr;
Expand All @@ -4170,50 +4170,76 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {
return nullptr;

Type ResultT;
if (auto *FD = dyn_cast<FuncDecl>(VD))
if (auto *FD = dyn_cast<FuncDecl>(VD)) {
if (FD->getGenericParams()) {
// Generic function cannot have opaque result type.
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Is this really the case? This seems to type check and compile just fine:

func foo<T>(_ t: T) -> some Any {
  return t
}

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@rintaro rintaro Jan 9, 2020 •
edited
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This code is only for conformance completion.

protocol MyProtocol {}
class C: MyProtocol {}

protocol P {
  associatedtype Assoc : MyProtocol
  func foo<T>(x: T) -> Assoc
}
struct S: P {
  func foo<T>(x: T) -> some MyProtocol { return C() }
}

This S.foo(x:) cannot be used to infer S.Assoc. Even if the user explicitly adds, for instance, typealias Assoc = C, func foo<T>(x: T) -> some MyProtocol doesn't satisfy the requirement.
So we can't use some MyProtocol as a conformance completion.

return nullptr;
}
ResultT = FD->getResultInterfaceType();
else if (auto *SD = dyn_cast<SubscriptDecl>(VD))
} else if (auto *SD = dyn_cast<SubscriptDecl>(VD)) {
if (SD->getGenericParams()) {
// Generic subscript cannot have opaque result type.
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This also works fine for me:

struct S<T> {
  subscript<U>(_ u: U) -> some Any {
    return u
  }
}

return nullptr;
}
ResultT = SD->getElementInterfaceType();
else if (auto *VarD = dyn_cast<VarDecl>(VD))
} else if (auto *VarD = dyn_cast<VarDecl>(VD)) {
ResultT = VarD->getInterfaceType();
else
return nullptr;

if (!ResultT->is<DependentMemberType>())
// The result is not associatedtype.
} else {
return nullptr;
}

// If associatedtype doesn't have conformance/superclass constraint, we
// can't use opaque type.
auto assocTyD = ResultT->castTo<DependentMemberType>()->getAssocType();
if (!assocTyD->getInherited().size())
if (!ResultT->is<DependentMemberType>() ||
!ResultT->castTo<DependentMemberType>()->getAssocType())
// The result is not a valid associatedtype.
return nullptr;

// Try substitution to see if the associated type is resolved to concrete
// type.
auto substMap = currTy->getMemberSubstitutionMap(
CurrDeclContext->getParentModule(), VD);
ResultT = ResultT.subst(substMap);
if (!ResultT || !ResultT->is<DependentMemberType>())
if (!ResultT.subst(substMap)->is<DependentMemberType>())
// If resolved print it.
return nullptr;

return assocTyD->getInherited()[0];
auto genericSig = VD->getDeclContext()->getGenericSignatureOfContext();

if (genericSig->isConcreteType(ResultT))
// If it has same type requrement, we will emit the concrete type.
return nullptr;

// Collect requirements on the associatedtype.
SmallVector<Type, 2> opaqueTypes;
bool hasExplicitAnyObject = false;
if (auto superTy = genericSig->getSuperclassBound(ResultT))
opaqueTypes.push_back(superTy);
for (auto proto : genericSig->getConformsTo(ResultT))
opaqueTypes.push_back(proto->getDeclaredInterfaceType());
if (auto layout = genericSig->getLayoutConstraint(ResultT))
hasExplicitAnyObject = layout->isClass();

if (!hasExplicitAnyObject) {
if (opaqueTypes.empty())
return nullptr;
if (opaqueTypes.size() == 1)
return opaqueTypes.front();
}
return ProtocolCompositionType::get(
VD->getASTContext(), opaqueTypes, hasExplicitAnyObject);
}

void addValueOverride(const ValueDecl *VD, DeclVisibilityKind Reason,
DynamicLookupInfo dynamicLookupInfo,
CodeCompletionResultBuilder &Builder,
bool hasDeclIntroducer) {
class DeclPrinter : public StreamPrinter {
TypeLoc OpaqueBaseTy;
Type OpaqueBaseTy;

public:
using StreamPrinter::StreamPrinter;

Optional<unsigned> NameOffset;

DeclPrinter(raw_ostream &OS, TypeLoc OpaqueBaseTy)
DeclPrinter(raw_ostream &OS, Type OpaqueBaseTy)
: StreamPrinter(OS), OpaqueBaseTy(OpaqueBaseTy) {}

void printDeclLoc(const Decl *D) override {
Expand All @@ -4225,7 +4251,7 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {
void printDeclResultTypePre(ValueDecl *VD, TypeLoc &TL) override {
if (!OpaqueBaseTy.isNull()) {
OS << "some ";
TL = OpaqueBaseTy;
TL = TypeLoc::withoutLoc(OpaqueBaseTy);
}
}
};
Expand All @@ -4235,7 +4261,7 @@ class CompletionOverrideLookup : public swift::VisibleDeclConsumer {
{
llvm::raw_svector_ostream OS(DeclStr);
DeclPrinter Printer(
OS, getOpaqueResultTypeLoc(VD, Reason, dynamicLookupInfo));
OS, getOpaqueResultType(VD, Reason, dynamicLookupInfo));
PrintOptions Options;
if (auto transformType = CurrDeclContext->getDeclaredTypeInContext())
Options.setBaseType(transformType);
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22 changes: 22 additions & 0 deletions test/IDE/complete_crossmodule.swift
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@@ -0,0 +1,22 @@
// RUN: %empty-directory(%t)
// RUN: %{python} %utils/split_file.py -o %t %s

// RUN: %target-swift-frontend -emit-module -o %t/MyModule.swiftmodule %t/MyModule.swift
// RUN: %target-swift-ide-test -code-completion -source-filename %t/Test.swift -I %t -code-completion-token=OPAQUE_RESULT | %FileCheck --check-prefix=OPAQUE_RESULT %s

// BEGIN MyModule.swift

public protocol HasAssocWithConstraint {
associatedtype AssocWithContraint: HasAssocWithConstraint
var value: AssocWithContraint { get }
}

// BEGIN Test.swift
import MyModule

struct MyValue: HasAssocWithConstraint {
var #^OPAQUE_RESULT^#
// OPAQUE_RESULT: Begin completions
// OPAQUE_RESULT-DAG: Decl[InstanceVar]/Super: value: some HasAssocWithConstraint;
// OPAQUE_RESULT: End completions
}
36 changes: 32 additions & 4 deletions test/IDE/complete_opaque_result.swift
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Expand Up @@ -92,7 +92,7 @@ protocol HasAssocWithSuperClassConstraint {
}
protocol HasAssocWithCompositionConstraint {
associatedtype AssocWithCompositionConstraint: MyClass & MyProtocol
subscript<T>(idx: T) -> AssocWithCompositionConstraint where T: Comparable { get }
subscript(idx: Int) -> AssocWithCompositionConstraint { get }
}
protocol HasAssocWithDefault {
associatedtype AssocWithDefault = MyEnum
Expand All @@ -102,22 +102,46 @@ protocol HasAssocWithConstraintAndDefault {
associatedtype AssocWithConstraintAndDefault: MyProtocol = ConcreteMyProtocol
func returnAssocWithConstraintAndDefault() -> AssocWithConstraintAndDefault
}
protocol HasAssocWithAnyObjectConstraint {
associatedtype AssocWithAnyObjectConstraint: AnyObject & MyProtocol
func returnAssocWithAnyObjectConstraint() -> AssocWithAnyObjectConstraint
}
protocol HasAssocWithConstraintOnProto where Self.AssocWithConstraintOnProto : MyProtocol {
associatedtype AssocWithConstraintOnProto
func returnAssocWithConstraintOnProto() -> AssocWithConstraintOnProto
}
protocol HasAssocWithSameTypeConstraint where Self.AssocWithSameTypeConstraint == ConcreteMyProtocol {
associatedtype AssocWithSameTypeConstraint : MyProtocol
func returnAssocWithSameTypeConstraint() -> AssocWithSameTypeConstraint
}
protocol HasAssocWithConformanceConstraintGeneric {
associatedtype AssocWithConformanceConstraintGeneric: MyProtocol
func returnAssocWithConformanceConstraintGeneric<T>(arg: T) -> AssocWithConformanceConstraintGeneric
}

class TestClass :
HasAssocPlain,
HasAssocWithConformanceConstraint,
HasAssocWithSuperClassConstraint,
HasAssocWithCompositionConstraint,
HasAssocWithDefault,
HasAssocWithConstraintAndDefault {
HasAssocWithConstraintAndDefault,
HasAssocWithAnyObjectConstraint,
HasAssocWithConstraintOnProto,
HasAssocWithSameTypeConstraint,
HasAssocWithConformanceConstraintGeneric {
#^OVERRIDE_TestClass^#
// OVERRIDE: Begin completions
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocPlain() -> AssocPlain {|};
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithConformanceConstraint(fn: (Int) -> Int) -> some MyProtocol {|};
// OVERRIDE-DAG: Decl[InstanceVar]/Super: var valAssocWithSuperClassConstraint: some MyClass;
// OVERRIDE-DAG: Decl[Subscript]/Super: subscript<T>(idx: T) -> some MyClass & MyProtocol where T : Comparable {|};
// OVERRIDE-DAG: Decl[Subscript]/Super: subscript(idx: Int) -> some MyClass & MyProtocol {|};
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithDefault() -> MyEnum {|};
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithConstraintAndDefault() -> ConcreteMyProtocol {|};
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithAnyObjectConstraint() -> some MyProtocol & AnyObject {|}
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithConstraintOnProto() -> some MyProtocol {|}
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithSameTypeConstraint() -> AssocWithSameTypeConstraint {|}
// OVERRIDE-DAG: Decl[InstanceMethod]/Super: func returnAssocWithConformanceConstraintGeneric<T>(arg: T) -> AssocWithConformanceConstraintGeneric {|}
// OVERRIDE: End completions
}

Expand All @@ -127,7 +151,11 @@ struct TestStruct :
HasAssocWithSuperClassConstraint,
HasAssocWithCompositionConstraint,
HasAssocWithDefault,
HasAssocWithConstraintAndDefault {
HasAssocWithConstraintAndDefault,
HasAssocWithAnyObjectConstraint,
HasAssocWithConstraintOnProto,
HasAssocWithSameTypeConstraint,
HasAssocWithConformanceConstraintGeneric {
#^OVERRIDE_TestStruct^#
}

Expand Down