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UnqualifiedLookup.cpp
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//===--- UnqualifiedLookup.cpp - Swift Name Lookup Routines ---------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
///
/// This file implements the construction of an UnqualifiedLookup, which entails
/// performing the lookup.
///
//===----------------------------------------------------------------------===//
#include "swift/AST/ASTContext.h"
#include "swift/AST/ASTVisitor.h"
#include "swift/AST/ClangModuleLoader.h"
#include "swift/AST/DebuggerClient.h"
#include "swift/AST/ExistentialLayout.h"
#include "swift/AST/Initializer.h"
#include "swift/AST/LazyResolver.h"
#include "swift/AST/NameLookup.h"
#include "swift/AST/NameLookupRequests.h"
#include "swift/AST/ParameterList.h"
#include "swift/AST/ReferencedNameTracker.h"
#include "swift/Basic/STLExtras.h"
#include "swift/Basic/SourceManager.h"
#include "swift/Basic/Statistic.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#define DEBUG_TYPE "namelookup"
using namespace swift;
using namespace swift::namelookup;
namespace {
/// Determine whether unqualified lookup should look at the members of the
/// given nominal type or extension, vs. only looking at type parameters.
template <typename D> bool shouldLookupMembers(D *decl, SourceLoc loc) {
// Only look at members of this type (or its inherited types) when
// inside the body or a protocol's top-level 'where' clause. (Why the
// 'where' clause? Because that's where you put constraints on
// inherited associated types.)
// When we have no source-location information, we have to perform member
// lookup.
if (loc.isInvalid() || decl->getBraces().isInvalid())
return true;
// Within the braces, always look for members.
auto &ctx = decl->getASTContext();
auto braces = decl->getBraces();
if (braces.Start != braces.End &&
ctx.SourceMgr.rangeContainsTokenLoc(braces, loc))
return true;
// Within 'where' clause, we can also look for members.
if (auto *whereClause = decl->getTrailingWhereClause()) {
SourceRange whereClauseRange = whereClause->getSourceRange();
if (whereClauseRange.isValid() &&
ctx.SourceMgr.rangeContainsTokenLoc(whereClauseRange, loc)) {
return true;
}
}
// Don't look at the members.
return false;
}
} // end anonymous namespace
namespace {
/// Because UnqualifiedLookup does all of its work in the constructor,
/// a factory class is needed to hold all of the inputs and outputs so
/// that the construction code can be decomposed into bite-sized pieces.
class UnqualifiedLookupFactory {
friend class ASTScopeDeclConsumerForUnqualifiedLookup;
public:
using Flags = UnqualifiedLookup::Flags;
using Options = UnqualifiedLookup::Options;
using ResultsVector = UnqualifiedLookup::ResultsVector;
private:
struct ContextAndResolvedIsCascadingUse {
DeclContext *const DC;
const bool isCascadingUse;
};
/// Finds lookup results based on the types that self conforms to.
/// For instance, self always conforms to a struct, enum or class.
/// But in addition, self could conform to any number of protocols.
/// For example, when there's a protocol extension, e.g. extension P where
/// self: P2, self also conforms to P2 so P2 must be searched.
class ResultFinderForTypeContext {
UnqualifiedLookupFactory *const factory;
/// Nontypes are formally members of the base type, i.e. the dynamic type
/// of the activation record.
DeclContext *const dynamicContext;
/// Types are formally members of the metatype, i.e. the static type of the
/// activation record.
DeclContext *const staticContext;
using SelfBounds = SmallVector<NominalTypeDecl *, 2>;
SelfBounds selfBounds;
public:
/// \p staticContext is also the context from which to derive the self types
ResultFinderForTypeContext(UnqualifiedLookupFactory *factory,
DeclContext *dynamicContext,
DeclContext *staticContext);
void dump() const;
private:
SelfBounds findSelfBounds(DeclContext *dc);
// Classify this declaration.
// Types are formally members of the metatype.
DeclContext *whereValueIsMember(const ValueDecl *const member) const {
return isa<TypeDecl>(member) ? staticContext : dynamicContext;
}
public:
/// Do the lookups and add matches to results.
void findResults(const DeclName &Name, bool isCascadingUse,
NLOptions baseNLOptions, DeclContext *contextForLookup,
SmallVectorImpl<LookupResultEntry> &results) const;
};
enum class AddGenericParameters { Yes, No };
#ifndef NDEBUG
/// A consumer for debugging that lets the UnqualifiedLookupFactory know when
/// finding something.
class InstrumentedNamedDeclConsumer : public NamedDeclConsumer {
virtual void anchor() override;
UnqualifiedLookupFactory *factory;
public:
InstrumentedNamedDeclConsumer(UnqualifiedLookupFactory *factory,
DeclName name,
SmallVectorImpl<LookupResultEntry> &results,
bool isTypeLookup)
: NamedDeclConsumer(name, results, isTypeLookup), factory(factory) {}
virtual void foundDecl(ValueDecl *VD, DeclVisibilityKind Reason,
DynamicLookupInfo dynamicLookupInfo = {}) override {
unsigned before = results.size();
NamedDeclConsumer::foundDecl(VD, Reason, dynamicLookupInfo);
unsigned after = results.size();
if (after > before)
factory->addedResult(results.back());
}
};
#endif
// Inputs
const DeclName Name;
DeclContext *const DC;
ModuleDecl &M;
const ASTContext &Ctx;
LazyResolver *const TypeResolver;
const SourceLoc Loc;
const SourceManager &SM;
/// Used to find the file-local names.
DebuggerClient *const DebugClient;
const Options options;
const bool isOriginallyTypeLookup;
const NLOptions baseNLOptions;
// Transputs
#ifndef NDEBUG
InstrumentedNamedDeclConsumer Consumer;
#else
NamedDeclConsumer Consumer;
#endif
// Outputs
SmallVectorImpl<LookupResultEntry> &Results;
size_t &IndexOfFirstOuterResult;
ResultsVector UnavailableInnerResults;
#ifndef NDEBUG
static unsigned lookupCounter;
static const unsigned targetLookup;
#endif
public: // for exp debugging
SourceFile const *recordedSF = nullptr;
bool recordedIsCascadingUse = false;
unsigned resultsSizeBeforeLocalsPass = ~0;
public:
// clang-format off
UnqualifiedLookupFactory(DeclName Name,
DeclContext *const DC,
LazyResolver *TypeResolver,
SourceLoc Loc,
Options options,
UnqualifiedLookup &lookupToBeCreated);
UnqualifiedLookupFactory(DeclName Name,
DeclContext *const DC,
LazyResolver *TypeResolver,
SourceLoc Loc,
Options options,
SmallVectorImpl<LookupResultEntry> &Results,
size_t &IndexOfFirstOuterResult);
// clang-format on
void performUnqualifiedLookup();
private:
struct ContextAndUnresolvedIsCascadingUse {
DeclContext *whereToLook;
Optional<bool> isCascadingUse;
ContextAndResolvedIsCascadingUse resolve(const bool resolution) const {
return ContextAndResolvedIsCascadingUse{
whereToLook, isCascadingUse.getValueOr(resolution)};
}
};
bool useASTScopesForExperimentalLookup() const;
/// For testing, assume this lookup is enabled:
bool useASTScopesForExperimentalLookupIfEnabled() const;
void lookUpTopLevelNamesInModuleScopeContext(DeclContext *);
void experimentallyLookInASTScopes();
/// Can lookup stop searching for results, assuming hasn't looked for outer
/// results yet?
bool isFirstResultEnough() const;
/// Every time lookup finishes searching a scope, call me
/// to record the dividing line between results from first fruitful scope and
/// the result.
void recordCompletionOfAScope();
template <typename Fn> void ifNotDoneYet(Fn fn) {
recordCompletionOfAScope();
if (!isFirstResultEnough())
fn();
}
template <typename Fn1, typename Fn2> void ifNotDoneYet(Fn1 fn1, Fn2 fn2) {
ifNotDoneYet(fn1);
ifNotDoneYet(fn2);
}
#pragma mark context-based lookup declarations
void lookupOperatorInDeclContexts(ContextAndUnresolvedIsCascadingUse);
void lookupNamesIntroducedBy(const ContextAndUnresolvedIsCascadingUse);
void finishLookingInContext(
AddGenericParameters addGenericParameters,
DeclContext *lookupContextForThisContext,
Optional<ResultFinderForTypeContext> &&resultFinderForTypeContext,
Optional<bool> isCascadingUse);
void lookupInModuleScopeContext(DeclContext *, Optional<bool> isCascadingUse);
void lookupNamesIntroducedByPatternBindingInitializer(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse);
void
lookupNamesIntroducedByLazyVariableInitializer(PatternBindingInitializer *PBI,
ParamDecl *selfParam,
Optional<bool> isCascadingUse);
void lookupNamesIntroducedByInitializerOfStoredPropertyOfAType(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse);
/// An initializer of a global name, or a function-likelocal name.
void lookupNamesIntroducedByInitializerOfGlobalOrLocal(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse);
void lookupNamesIntroducedByFunctionDecl(AbstractFunctionDecl *AFD,
Optional<bool> isCascadingUse);
void lookupNamesIntroducedByMemberFunction(AbstractFunctionDecl *AFD,
bool isCascadingUse);
void lookupNamesIntroducedByPureFunction(AbstractFunctionDecl *AFD,
bool isCascadingUse);
void lookupNamesIntroducedByClosure(AbstractClosureExpr *ACE,
Optional<bool> isCascadingUse);
template <typename NominalTypeDeclOrExtensionDecl>
void lookupNamesIntroducedByNominalTypeOrExtension(
NominalTypeDeclOrExtensionDecl *D, Optional<bool> isCascadingUse);
void lookupNamesIntroducedByDefaultArgumentInitializer(
DefaultArgumentInitializer *I, Optional<bool> isCascadingUse);
void lookupNamesIntroducedByMiscContext(DeclContext *dc,
Optional<bool> isCascadingUse);
void lookForLocalVariablesIn(AbstractFunctionDecl *AFD,
Optional<bool> isCascadingUse);
void lookForLocalVariablesIn(ClosureExpr *);
void lookForLocalVariablesIn(SourceFile *);
bool isOutsideBodyOfFunction(const AbstractFunctionDecl *const AFD) const;
void addGenericParametersForContext(DeclContext *dc);
void addGenericParametersForContext(GenericParamList *);
/// Consume generic parameters
void addGenericParametersForFunction(AbstractFunctionDecl *AFD);
static GenericParamList *getGenericParams(const DeclContext *const dc);
/// For diagnostic purposes, move aside the unavailables, and put
/// them back as a last-ditch effort.
/// Could be cleaner someday with a richer interface to UnqualifiedLookup.
void setAsideUnavailableResults(size_t firstPossiblyUnavailableResult);
void recordDependencyOnTopLevelName(DeclContext *topLevelContext,
DeclName name, bool isCascadingUse);
void addImportedResults(DeclContext *const dc);
void addNamesKnownToDebugClient(DeclContext *dc);
void addUnavailableInnerResults();
void lookForAModuleWithTheGivenName(DeclContext *const dc);
#pragma mark common helper declarations
static NLOptions
computeBaseNLOptions(const UnqualifiedLookup::Options options,
const bool isOriginallyTypeLookup);
Optional<bool> getInitialIsCascadingUse() const {
return options.contains(Flags::KnownPrivate) ? Optional<bool>(false)
: None;
}
static bool resolveIsCascadingUse(const DeclContext *const dc,
Optional<bool> isCascadingUse,
bool onlyCareAboutFunctionBody) {
return isCascadingUse.getValueOr(dc->isCascadingContextForLookup(
/*functionsAreNonCascading=*/onlyCareAboutFunctionBody));
}
static bool resolveIsCascadingUse(ContextAndUnresolvedIsCascadingUse x,
bool onlyCareAboutFunctionBody) {
return resolveIsCascadingUse(x.whereToLook, x.isCascadingUse,
onlyCareAboutFunctionBody);
}
void findResultsAndSaveUnavailables(
DeclContext *lookupContextForThisContext,
ResultFinderForTypeContext &&resultFinderForTypeContext,
bool isCascadingUse, NLOptions baseNLOptions);
public:
void dump() const;
void dumpScopes() const;
void print(raw_ostream &OS) const;
void dumpResults() const;
bool verifyEqualTo(const UnqualifiedLookupFactory &&, const char *thisLabel,
const char *otherLabel) const;
/// Legacy lookup is wrong here; we should NOT find this symbol.
bool shouldDiffer() const;
StringRef getSourceFileName() const;
#ifndef NDEBUG
bool isTargetLookup() const;
void stopForDebuggingIfStartingTargetLookup(bool isASTScopeLookup) const;
void stopForDebuggingIfDuringTargetLookup(bool isASTScopeLookup) const;
void
stopForDebuggingIfAddingTargetLookupResult(const LookupResultEntry &) const;
void addedResult(const LookupResultEntry &) const;
#endif
};
} // namespace
namespace {
/// Used to gather lookup results
class ASTScopeDeclConsumerForUnqualifiedLookup
: public AbstractASTScopeDeclConsumer {
UnqualifiedLookupFactory &factory;
public:
ASTScopeDeclConsumerForUnqualifiedLookup(UnqualifiedLookupFactory &factory)
: factory(factory) {}
virtual ~ASTScopeDeclConsumerForUnqualifiedLookup() = default;
bool consume(ArrayRef<ValueDecl *> values, DeclVisibilityKind vis,
NullablePtr<DeclContext> baseDC = nullptr) override;
/// returns true if finished and new value for isCascadingUse
bool lookInMembers(NullablePtr<DeclContext> selfDC,
DeclContext *const scopeDC, NominalTypeDecl *const nominal,
function_ref<bool(Optional<bool>)>) override;
#ifndef NDEBUG
void startingNextLookupStep() override {
factory.stopForDebuggingIfDuringTargetLookup(true);
}
bool isTargetLookup() const override { return factory.isTargetLookup(); }
void finishingLookup(std::string msg) const override {
if (isTargetLookup())
llvm::errs() << "Finishing lookup: " << msg << "\n";
}
#endif
};
} // namespace
#pragma mark UnqualifiedLookupFactory functions
// clang-format off
UnqualifiedLookupFactory::UnqualifiedLookupFactory(
DeclName Name,
DeclContext *const DC,
LazyResolver *TypeResolver,
SourceLoc Loc,
Options options,
UnqualifiedLookup &lookupToBeCreated)
: UnqualifiedLookupFactory(Name, DC, TypeResolver, Loc, options,
lookupToBeCreated.Results,
lookupToBeCreated.IndexOfFirstOuterResult)
{}
UnqualifiedLookupFactory::UnqualifiedLookupFactory(
DeclName Name,
DeclContext *const DC,
LazyResolver *TypeResolver,
SourceLoc Loc,
Options options,
SmallVectorImpl<LookupResultEntry> &Results,
size_t &IndexOfFirstOuterResult)
:
Name(Name),
DC(DC),
M(*DC->getParentModule()),
Ctx(M.getASTContext()),
TypeResolver(TypeResolver ? TypeResolver : Ctx.getLazyResolver()),
Loc(Loc),
SM(Ctx.SourceMgr),
DebugClient(M.getDebugClient()),
options(options),
isOriginallyTypeLookup(options.contains(Flags::TypeLookup)),
baseNLOptions(computeBaseNLOptions(options, isOriginallyTypeLookup)),
#ifdef NDEBUG
Consumer(Name, Results, isOriginallyTypeLookup),
#else
Consumer(this, Name, Results, isOriginallyTypeLookup),
#endif
Results(Results),
IndexOfFirstOuterResult(IndexOfFirstOuterResult)
{}
// clang-format on
void UnqualifiedLookupFactory::performUnqualifiedLookup() {
#ifndef NDEBUG
++lookupCounter;
stopForDebuggingIfStartingTargetLookup(false);
#endif
const Optional<bool> initialIsCascadingUse = getInitialIsCascadingUse();
ContextAndUnresolvedIsCascadingUse contextAndIsCascadingUse{
DC, initialIsCascadingUse};
const bool compareToASTScopes = Ctx.LangOpts.CompareToASTScopeLookup;
if (useASTScopesForExperimentalLookup() && !compareToASTScopes) {
static bool haveWarned = false;
if (!haveWarned && Ctx.LangOpts.WarnIfASTScopeLookup) {
haveWarned = true;
llvm::errs() << "WARNING: TRYING Scope exclusively\n";
}
experimentallyLookInASTScopes();
return;
}
if (Name.isOperator())
lookupOperatorInDeclContexts(contextAndIsCascadingUse);
else
lookupNamesIntroducedBy(contextAndIsCascadingUse);
if (compareToASTScopes && useASTScopesForExperimentalLookupIfEnabled()) {
ResultsVector results;
size_t indexOfFirstOuterResult = 0;
UnqualifiedLookupFactory scopeLookup(Name, DC, TypeResolver, Loc, options,
results, indexOfFirstOuterResult);
scopeLookup.experimentallyLookInASTScopes();
assert(verifyEqualTo(std::move(scopeLookup), "UnqualifedLookup",
"Scope lookup"));
}
}
void UnqualifiedLookupFactory::lookUpTopLevelNamesInModuleScopeContext(
DeclContext *DC) {
// TODO: Does the debugger client care about compound names?
if (Name.isSimpleName() && !Name.isSpecial() && DebugClient &&
DebugClient->lookupOverrides(Name.getBaseName(), DC, Loc,
isOriginallyTypeLookup, Results))
return;
addImportedResults(DC);
addNamesKnownToDebugClient(DC);
if (Results.empty()) {
// If we still haven't found anything, but we do have some
// declarations that are "unavailable in the current Swift", drop
// those in.
addUnavailableInnerResults();
if (Results.empty())
lookForAModuleWithTheGivenName(DC);
}
recordCompletionOfAScope();
}
bool UnqualifiedLookupFactory::useASTScopesForExperimentalLookup() const {
return Ctx.LangOpts.EnableASTScopeLookup &&
useASTScopesForExperimentalLookupIfEnabled();
}
bool UnqualifiedLookupFactory::useASTScopesForExperimentalLookupIfEnabled()
const {
return Loc.isValid() && DC->getParentSourceFile() &&
DC->getParentSourceFile()->Kind != SourceFileKind::REPL &&
DC->getParentSourceFile()->Kind != SourceFileKind::SIL;
}
#pragma mark context-based lookup definitions
void UnqualifiedLookupFactory::lookupOperatorInDeclContexts(
const ContextAndUnresolvedIsCascadingUse contextAndUseArg) {
ContextAndResolvedIsCascadingUse contextAndResolvedIsCascadingUse{
// Operators are global
contextAndUseArg.whereToLook->getModuleScopeContext(),
resolveIsCascadingUse(contextAndUseArg,
/*onlyCareAboutFunctionBody*/ true)};
lookupInModuleScopeContext(contextAndResolvedIsCascadingUse.DC,
contextAndResolvedIsCascadingUse.isCascadingUse);
}
// TODO: Unify with LookupVisibleDecls.cpp::lookupVisibleDeclsImpl
void UnqualifiedLookupFactory::lookupNamesIntroducedBy(
const ContextAndUnresolvedIsCascadingUse contextAndIsCascadingUseArg) {
#ifndef NDEBUG
stopForDebuggingIfDuringTargetLookup(false);
#endif
DeclContext *const dc = contextAndIsCascadingUseArg.whereToLook;
const auto isCascadingUseSoFar = contextAndIsCascadingUseArg.isCascadingUse;
if (dc->isModuleScopeContext())
lookupInModuleScopeContext(dc, isCascadingUseSoFar);
else if (auto *PBI = dyn_cast<PatternBindingInitializer>(dc))
lookupNamesIntroducedByPatternBindingInitializer(PBI, isCascadingUseSoFar);
else if (auto *AFD = dyn_cast<AbstractFunctionDecl>(dc))
lookupNamesIntroducedByFunctionDecl(AFD, isCascadingUseSoFar);
else if (auto *ACE = dyn_cast<AbstractClosureExpr>(dc))
lookupNamesIntroducedByClosure(ACE, isCascadingUseSoFar);
else if (auto *ED = dyn_cast<ExtensionDecl>(dc))
lookupNamesIntroducedByNominalTypeOrExtension(ED, isCascadingUseSoFar);
else if (auto *ND = dyn_cast<NominalTypeDecl>(dc))
lookupNamesIntroducedByNominalTypeOrExtension(ND, isCascadingUseSoFar);
else if (auto I = dyn_cast<DefaultArgumentInitializer>(dc))
lookupNamesIntroducedByDefaultArgumentInitializer(I, isCascadingUseSoFar);
else
lookupNamesIntroducedByMiscContext(dc, isCascadingUseSoFar);
}
void UnqualifiedLookupFactory::lookupInModuleScopeContext(
DeclContext *dc, Optional<bool> isCascadingUse) {
if (auto SF = dyn_cast<SourceFile>(dc)) {
resultsSizeBeforeLocalsPass = Results.size();
lookForLocalVariablesIn(SF);
}
ifNotDoneYet([&] {
// If no result has been found yet, the dependency must be on a top-level
// name, since up to now, the search has been for non-top-level names.
recordDependencyOnTopLevelName(dc, Name, isCascadingUse.getValueOr(true));
lookUpTopLevelNamesInModuleScopeContext(dc);
});
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByPatternBindingInitializer(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse) {
// Lazy variable initializer contexts have a 'self' parameter for
// instance member lookup.
if (auto *selfParam = PBI->getImplicitSelfDecl())
lookupNamesIntroducedByLazyVariableInitializer(PBI, selfParam,
isCascadingUse);
else if (PBI->getParent()->isTypeContext())
lookupNamesIntroducedByInitializerOfStoredPropertyOfAType(PBI,
isCascadingUse);
else
lookupNamesIntroducedByInitializerOfGlobalOrLocal(PBI, isCascadingUse);
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByLazyVariableInitializer(
PatternBindingInitializer *PBI, ParamDecl *selfParam,
Optional<bool> isCascadingUse) {
Consumer.foundDecl(selfParam, DeclVisibilityKind::FunctionParameter);
ifNotDoneYet([&] {
DeclContext *const patternContainer = PBI->getParent();
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
patternContainer,
ResultFinderForTypeContext(this, PBI, patternContainer),
resolveIsCascadingUse(PBI, isCascadingUse,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
});
}
void UnqualifiedLookupFactory::
lookupNamesIntroducedByInitializerOfStoredPropertyOfAType(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse) {
// Initializers for stored properties of types perform static
// lookup into the surrounding context.
DeclContext *const storedPropertyContainer = PBI->getParent();
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
storedPropertyContainer,
ResultFinderForTypeContext(
this, storedPropertyContainer, storedPropertyContainer),
resolveIsCascadingUse(storedPropertyContainer, None,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
}
void UnqualifiedLookupFactory::
lookupNamesIntroducedByInitializerOfGlobalOrLocal(
PatternBindingInitializer *PBI, Optional<bool> isCascadingUse) {
// There's not much to find here, we'll keep going up to a parent
// context.
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
PBI,
None, // not looking in the partic type
resolveIsCascadingUse(PBI, isCascadingUse,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByFunctionDecl(
AbstractFunctionDecl *AFD, Optional<bool> isCascadingUseArg) {
// DOUG: how does this differ from isOutsideBodyOfFunction below?
const bool isCascadingUse =
AFD->isCascadingContextForLookup(false) &&
(isCascadingUseArg.getValueOr(
Loc.isInvalid() || !AFD->getBody() ||
!SM.rangeContainsTokenLoc(AFD->getBodySourceRange(), Loc)));
if (AFD->getDeclContext()->isTypeContext())
lookupNamesIntroducedByMemberFunction(AFD, isCascadingUse);
else
lookupNamesIntroducedByPureFunction(AFD, isCascadingUse);
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByMemberFunction(
AbstractFunctionDecl *AFD, bool isCascadingUse) {
lookForLocalVariablesIn(AFD, isCascadingUse);
ifNotDoneYet(
[&] {
// If we're inside a function context, we're about to move to
// the parent DC, so we have to check the function's generic
// parameters first.
// Cannot start here in finishLookingInContext because AFD's
// getOuterParameters may be null even when AFD's parent has generics.
addGenericParametersForFunction(AFD);
},
[&] {
DeclContext *const fnDeclContext = AFD->getDeclContext();
// If we're not in the body of the function (for example, we
// might be type checking a default argument expression and
// performing name lookup from there), the base declaration
// is the nominal type, not 'self'.
DeclContext *const BaseDC =
isOutsideBodyOfFunction(AFD) ? fnDeclContext : AFD;
// If we are inside of a method, check to see if there are any ivars in
// scope, and if so, whether this is a reference to one of them.
// FIXME: We should persist this information between lookups.
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
AFD->getParent(),
ResultFinderForTypeContext(this, BaseDC, fnDeclContext),
isCascadingUse);
// clang-format on
});
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByPureFunction(
AbstractFunctionDecl *AFD, bool isCascadingUse) {
lookForLocalVariablesIn(AFD, isCascadingUse);
ifNotDoneYet([&] {
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
AFD,
None,
isCascadingUse);
});
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByClosure(
AbstractClosureExpr *ACE, Optional<bool> isCascadingUse) {
if (auto *CE = dyn_cast<ClosureExpr>(ACE))
lookForLocalVariablesIn(CE);
ifNotDoneYet([&] {
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
ACE,
None,
resolveIsCascadingUse(ACE, isCascadingUse,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
});
}
template <typename NominalTypeDeclOrExtensionDecl>
void UnqualifiedLookupFactory::lookupNamesIntroducedByNominalTypeOrExtension(
NominalTypeDeclOrExtensionDecl *D, Optional<bool> isCascadingUse) {
// clang-format off
finishLookingInContext(
AddGenericParameters::Yes,
D,
shouldLookupMembers(D, Loc)
? Optional<ResultFinderForTypeContext>(
ResultFinderForTypeContext(this, D, D))
: None,
resolveIsCascadingUse(D, isCascadingUse,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
}
void UnqualifiedLookupFactory::
lookupNamesIntroducedByDefaultArgumentInitializer(
DefaultArgumentInitializer *I, Optional<bool> isCascadingUse) {
// In a default argument, skip immediately out of both the
// initializer and the function.
finishLookingInContext(AddGenericParameters::No, I->getParent(), None, false);
}
void UnqualifiedLookupFactory::lookupNamesIntroducedByMiscContext(
DeclContext *dc, Optional<bool> isCascadingUse) {
// clang-format off
assert(isa<TopLevelCodeDecl>(dc) ||
isa<Initializer>(dc) ||
isa<TypeAliasDecl>(dc) ||
isa<SubscriptDecl>(dc));
finishLookingInContext(
AddGenericParameters::Yes,
dc,
None,
resolveIsCascadingUse(DC, isCascadingUse,
/*onlyCareAboutFunctionBody=*/false));
// clang-format on
}
void UnqualifiedLookupFactory::finishLookingInContext(
const AddGenericParameters addGenericParameters,
DeclContext *const lookupContextForThisContext,
Optional<ResultFinderForTypeContext> &&resultFinderForTypeContext,
const Optional<bool> isCascadingUse) {
#ifndef NDEBUG
stopForDebuggingIfDuringTargetLookup(false);
#endif
// When a generic has the same name as a member, Swift prioritizes the generic
// because the member could still be named by qualifying it. But there is no
// corresponding way to qualify a generic parameter.
// So, look for generics first.
if (addGenericParameters == AddGenericParameters::Yes)
addGenericParametersForContext(lookupContextForThisContext);
ifNotDoneYet(
[&] {
if (resultFinderForTypeContext)
findResultsAndSaveUnavailables(lookupContextForThisContext,
std::move(*resultFinderForTypeContext),
*isCascadingUse, baseNLOptions);
},
// Recurse into the next context.
[&] {
lookupNamesIntroducedBy(ContextAndUnresolvedIsCascadingUse{
lookupContextForThisContext->getParentForLookup(), isCascadingUse});
});
}
void UnqualifiedLookupFactory::lookForLocalVariablesIn(
AbstractFunctionDecl *AFD, Optional<bool> isCascadingUse) {
// Look for local variables; normally, the parser resolves these
// for us, but it can't do the right thing inside local types.
// FIXME: when we can parse and typecheck the function body partially
// for code completion, AFD->getBody() check can be removed.
if (Loc.isInvalid() || !AFD->getBody()) {
return;
}
namelookup::FindLocalVal localVal(SM, Loc, Consumer);
localVal.visit(AFD->getBody());
ifNotDoneYet([&] {
if (auto *P = AFD->getImplicitSelfDecl())
localVal.checkValueDecl(P, DeclVisibilityKind::FunctionParameter);
localVal.checkParameterList(AFD->getParameters());
});
}
void UnqualifiedLookupFactory::lookForLocalVariablesIn(ClosureExpr *CE) {
// Look for local variables; normally, the parser resolves these
// for us, but it can't do the right thing inside local types.
if (Loc.isInvalid())
return;
namelookup::FindLocalVal localVal(SM, Loc, Consumer);
if (auto body = CE->getBody())
localVal.visit(body);
ifNotDoneYet([&] {
if (auto params = CE->getParameters())
localVal.checkParameterList(params);
});
}
void UnqualifiedLookupFactory::lookForLocalVariablesIn(SourceFile *SF) {
if (Loc.isInvalid())
return;
// Look for local variables in top-level code; normally, the parser
// resolves these for us, but it can't do the right thing for
// local types.
namelookup::FindLocalVal localVal(SM, Loc, Consumer);
localVal.checkSourceFile(*SF);
}
bool UnqualifiedLookupFactory::isOutsideBodyOfFunction(
const AbstractFunctionDecl *const AFD) const {
return !AFD->isImplicit() && Loc.isValid() &&
AFD->getBodySourceRange().isValid() &&
!SM.rangeContainsTokenLoc(AFD->getBodySourceRange(), Loc);
}
GenericParamList *
UnqualifiedLookupFactory::getGenericParams(const DeclContext *const dc) {
if (auto nominal = dyn_cast<NominalTypeDecl>(dc))
return nominal->getGenericParams();
if (auto ext = dyn_cast<ExtensionDecl>(dc))
return ext->getGenericParams();
if (auto subscript = dyn_cast<SubscriptDecl>(dc))
return subscript->getGenericParams();
if (auto func = dyn_cast<AbstractFunctionDecl>(dc))
return func->getGenericParams();
return nullptr;
}
void UnqualifiedLookupFactory::addGenericParametersForContext(
DeclContext *dc) {
// Generics can be nested, so visit the generic list, innermost first.
// Cannot use DeclContext::forEachGenericContext because this code breaks out
// if it finds a match and isFirstResultEnough()
addGenericParametersForContext(getGenericParams(dc));
}
void UnqualifiedLookupFactory::addGenericParametersForContext(
GenericParamList *dcGenericParams) {
if (!dcGenericParams)
return;
namelookup::FindLocalVal localVal(SM, Loc, Consumer);
localVal.checkGenericParams(dcGenericParams);
ifNotDoneYet([&] {
addGenericParametersForContext(
dcGenericParams->getOuterParameters());
});
}
void UnqualifiedLookupFactory::addGenericParametersForFunction(
AbstractFunctionDecl *AFD) {
GenericParamList *GenericParams = AFD->getGenericParams();
if (GenericParams) {
namelookup::FindLocalVal localVal(SM, Loc, Consumer);
localVal.checkGenericParams(GenericParams);
}
}
void UnqualifiedLookupFactory::ResultFinderForTypeContext::findResults(
const DeclName &Name, bool isCascadingUse, NLOptions baseNLOptions,
DeclContext *contextForLookup,
SmallVectorImpl<LookupResultEntry> &results) const {
// An optimization:
if (selfBounds.empty())
return;
const NLOptions options =
baseNLOptions | (isCascadingUse ? NL_KnownCascadingDependency
: NL_KnownNonCascadingDependency);
SmallVector<ValueDecl *, 4> Lookup;
contextForLookup->lookupQualified(selfBounds, Name, options, Lookup);
for (auto Result : Lookup) {
results.push_back(LookupResultEntry(whereValueIsMember(Result), Result));
#ifndef NDEBUG
factory->addedResult(results.back());
#endif
}
}
// TODO (someday): Instead of adding unavailable entries to Results,
// then later shunting them aside, just put them in the right place
// to begin with.
void UnqualifiedLookupFactory::setAsideUnavailableResults(
const size_t firstPossiblyUnavailableResult) {
// An optimization:
assert(Results.size() >= firstPossiblyUnavailableResult);
if (Results.size() == firstPossiblyUnavailableResult)
return;
// Predicate that determines whether a lookup result should
// be unavailable except as a last-ditch effort.
auto unavailableLookupResult = [&](const LookupResultEntry &result) {
auto &effectiveVersion = Ctx.LangOpts.EffectiveLanguageVersion;
return result.getValueDecl()->getAttrs().isUnavailableInSwiftVersion(
effectiveVersion);
};
// If all of the results we found are unavailable, keep looking.
auto begin = Results.begin() + firstPossiblyUnavailableResult;
if (std::all_of(begin, Results.end(), unavailableLookupResult)) {
// better to have more structure in results
UnavailableInnerResults.append(begin, Results.end());
Results.erase(begin, Results.end());
return;
}
// The debugger may have a different private discriminator
// in order to support lookup relative to the place where
// execution is suspended.
filterForDiscriminator(Results, DebugClient);
}
void UnqualifiedLookupFactory::recordDependencyOnTopLevelName(
DeclContext *topLevelContext, DeclName name, bool isCascadingUse) {
recordLookupOfTopLevelName(topLevelContext, Name, isCascadingUse);
recordedSF = dyn_cast<SourceFile>(topLevelContext);
recordedIsCascadingUse = isCascadingUse;
}
void UnqualifiedLookupFactory::addImportedResults(DeclContext *const dc) {
// Add private imports to the extra search list.
SmallVector<ModuleDecl::ImportedModule, 8> extraImports;
if (auto FU = dyn_cast<FileUnit>(dc)) {
ModuleDecl::ImportFilter importFilter;
importFilter |= ModuleDecl::ImportFilterKind::Private;
importFilter |= ModuleDecl::ImportFilterKind::ImplementationOnly;
FU->getImportedModules(extraImports, importFilter);
}
using namespace namelookup;
SmallVector<ValueDecl *, 8> CurModuleResults;
auto resolutionKind = isOriginallyTypeLookup ? ResolutionKind::TypesOnly
: ResolutionKind::Overloadable;
lookupInModule(&M, {}, Name, CurModuleResults, NLKind::UnqualifiedLookup,
resolutionKind, TypeResolver, dc, extraImports);
// Always perform name shadowing for type lookup.
if (options.contains(Flags::TypeLookup)) {
removeShadowedDecls(CurModuleResults, &M);
}
for (auto VD : CurModuleResults) {
Results.push_back(LookupResultEntry(VD));
#ifndef NDEBUG
addedResult(Results.back());
#endif
}
filterForDiscriminator(Results, DebugClient);
}
void UnqualifiedLookupFactory::addNamesKnownToDebugClient(DeclContext *dc) {