llvm-project/clang-tools-extra/clangd/FindTarget.cpp

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//===--- FindTarget.cpp - What does an AST node refer to? -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "FindTarget.h"
#include "AST.h"
#include "Logger.h"
#include "clang/AST/ASTTypeTraits.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/DeclarationName.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/NestedNameSpecifier.h"
#include "clang/AST/PrettyPrinter.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TemplateBase.h"
#include "clang/AST/Type.h"
#include "clang/AST/TypeLoc.h"
#include "clang/AST/TypeLocVisitor.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"
#include <utility>
namespace clang {
namespace clangd {
namespace {
using ast_type_traits::DynTypedNode;
LLVM_ATTRIBUTE_UNUSED std::string
nodeToString(const ast_type_traits::DynTypedNode &N) {
std::string S = N.getNodeKind().asStringRef();
{
llvm::raw_string_ostream OS(S);
OS << ": ";
N.print(OS, PrintingPolicy(LangOptions()));
}
std::replace(S.begin(), S.end(), '\n', ' ');
return S;
}
// TargetFinder locates the entities that an AST node refers to.
//
// Typically this is (possibly) one declaration and (possibly) one type, but
// may be more:
// - for ambiguous nodes like OverloadExpr
// - if we want to include e.g. both typedefs and the underlying type
//
// This is organized as a set of mutually recursive helpers for particular node
// types, but for most nodes this is a short walk rather than a deep traversal.
//
// It's tempting to do e.g. typedef resolution as a second normalization step,
// after finding the 'primary' decl etc. But we do this monolithically instead
// because:
// - normalization may require these traversals again (e.g. unwrapping a
// typedef reveals a decltype which must be traversed)
// - it doesn't simplify that much, e.g. the first stage must still be able
// to yield multiple decls to handle OverloadExpr
// - there are cases where it's required for correctness. e.g:
// template<class X> using pvec = vector<x*>; pvec<int> x;
// There's no Decl `pvec<int>`, we must choose `pvec<X>` or `vector<int*>`
// and both are lossy. We must know upfront what the caller ultimately wants.
//
// FIXME: improve common dependent scope using name lookup in primary templates.
// e.g. template<typename T> int foo() { return std::vector<T>().size(); }
// formally size() is unresolved, but the primary template is a good guess.
// This affects:
// - DependentTemplateSpecializationType,
// - DependentScopeMemberExpr
// - DependentScopeDeclRefExpr
// - DependentNameType
struct TargetFinder {
using RelSet = DeclRelationSet;
using Rel = DeclRelation;
llvm::SmallDenseMap<const Decl *, RelSet> Decls;
RelSet Flags;
static const Decl *getTemplatePattern(const Decl *D) {
if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(D)) {
return CRD->getTemplateInstantiationPattern();
} else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
return FD->getTemplateInstantiationPattern();
} else if (auto *VD = dyn_cast<VarDecl>(D)) {
// Hmm: getTIP returns its arg if it's not an instantiation?!
VarDecl *T = VD->getTemplateInstantiationPattern();
return (T == D) ? nullptr : T;
} else if (const auto *ED = dyn_cast<EnumDecl>(D)) {
return ED->getInstantiatedFromMemberEnum();
} else if (isa<FieldDecl>(D) || isa<TypedefNameDecl>(D)) {
const auto *ND = cast<NamedDecl>(D);
if (const DeclContext *Parent = dyn_cast_or_null<DeclContext>(
getTemplatePattern(llvm::cast<Decl>(ND->getDeclContext()))))
for (const NamedDecl *BaseND : Parent->lookup(ND->getDeclName()))
if (!BaseND->isImplicit() && BaseND->getKind() == ND->getKind())
return BaseND;
} else if (const auto *ECD = dyn_cast<EnumConstantDecl>(D)) {
if (const auto *ED = dyn_cast<EnumDecl>(ECD->getDeclContext())) {
if (const EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) {
for (const NamedDecl *BaseECD : Pattern->lookup(ECD->getDeclName()))
return BaseECD;
}
}
}
return nullptr;
}
template <typename T> void debug(T &Node, RelSet Flags) {
dlog("visit [{0}] {1}", Flags,
nodeToString(ast_type_traits::DynTypedNode::create(Node)));
}
void report(const Decl *D, RelSet Flags) {
dlog("--> [{0}] {1}", Flags,
nodeToString(ast_type_traits::DynTypedNode::create(*D)));
Decls[D] |= Flags;
}
public:
void add(const Decl *D, RelSet Flags) {
if (!D)
return;
debug(*D, Flags);
if (const UsingDirectiveDecl *UDD = llvm::dyn_cast<UsingDirectiveDecl>(D))
D = UDD->getNominatedNamespaceAsWritten();
if (const TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(D)) {
add(TND->getUnderlyingType(), Flags | Rel::Underlying);
Flags |= Rel::Alias; // continue with the alias.
} else if (const UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
for (const UsingShadowDecl *S : UD->shadows())
add(S->getUnderlyingDecl(), Flags | Rel::Underlying);
Flags |= Rel::Alias; // continue with the alias.
} else if (const auto *NAD = dyn_cast<NamespaceAliasDecl>(D)) {
add(NAD->getUnderlyingDecl(), Flags | Rel::Underlying);
Flags |= Rel::Alias; // continue with the alias
} else if (const UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D)) {
// Include the using decl, but don't traverse it. This may end up
// including *all* shadows, which we don't want.
report(USD->getUsingDecl(), Flags | Rel::Alias);
// Shadow decls are synthetic and not themselves interesting.
// Record the underlying decl instead, if allowed.
D = USD->getTargetDecl();
Flags |= Rel::Underlying; // continue with the underlying decl.
}
if (const Decl *Pat = getTemplatePattern(D)) {
assert(Pat != D);
add(Pat, Flags | Rel::TemplatePattern);
// Now continue with the instantiation.
Flags |= Rel::TemplateInstantiation;
}
report(D, Flags);
}
void add(const Stmt *S, RelSet Flags) {
if (!S)
return;
debug(*S, Flags);
struct Visitor : public ConstStmtVisitor<Visitor> {
TargetFinder &Outer;
RelSet Flags;
Visitor(TargetFinder &Outer, RelSet Flags) : Outer(Outer), Flags(Flags) {}
void VisitDeclRefExpr(const DeclRefExpr *DRE) {
const Decl *D = DRE->getDecl();
// UsingShadowDecl allows us to record the UsingDecl.
// getFoundDecl() returns the wrong thing in other cases (templates).
if (auto *USD = llvm::dyn_cast<UsingShadowDecl>(DRE->getFoundDecl()))
D = USD;
Outer.add(D, Flags);
}
void VisitMemberExpr(const MemberExpr *ME) {
const Decl *D = ME->getMemberDecl();
if (auto *USD =
llvm::dyn_cast<UsingShadowDecl>(ME->getFoundDecl().getDecl()))
D = USD;
Outer.add(D, Flags);
}
void VisitOverloadExpr(const OverloadExpr *OE) {
for (auto *D : OE->decls())
Outer.add(D, Flags);
}
void VisitCXXConstructExpr(const CXXConstructExpr *CCE) {
Outer.add(CCE->getConstructor(), Flags);
}
void VisitDesignatedInitExpr(const DesignatedInitExpr *DIE) {
for (const DesignatedInitExpr::Designator &D :
llvm::reverse(DIE->designators()))
if (D.isFieldDesignator()) {
Outer.add(D.getField(), Flags);
// We don't know which designator was intended, we assume the outer.
break;
}
}
void VisitObjCIvarRefExpr(const ObjCIvarRefExpr *OIRE) {
Outer.add(OIRE->getDecl(), Flags);
}
void VisitObjCMessageExpr(const ObjCMessageExpr *OME) {
Outer.add(OME->getMethodDecl(), Flags);
}
void VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *OPRE) {
if (OPRE->isExplicitProperty())
Outer.add(OPRE->getExplicitProperty(), Flags);
else {
if (OPRE->isMessagingGetter())
Outer.add(OPRE->getImplicitPropertyGetter(), Flags);
if (OPRE->isMessagingSetter())
Outer.add(OPRE->getImplicitPropertySetter(), Flags);
}
}
void VisitObjCProtocolExpr(const ObjCProtocolExpr *OPE) {
Outer.add(OPE->getProtocol(), Flags);
}
};
Visitor(*this, Flags).Visit(S);
}
void add(QualType T, RelSet Flags) {
if (T.isNull())
return;
debug(T, Flags);
struct Visitor : public TypeVisitor<Visitor> {
TargetFinder &Outer;
RelSet Flags;
Visitor(TargetFinder &Outer, RelSet Flags) : Outer(Outer), Flags(Flags) {}
void VisitTagType(const TagType *TT) {
Outer.add(TT->getAsTagDecl(), Flags);
}
void VisitDecltypeType(const DecltypeType *DTT) {
Outer.add(DTT->getUnderlyingType(), Flags | Rel::Underlying);
}
void VisitDeducedType(const DeducedType *DT) {
// FIXME: In practice this doesn't work: the AutoType you find inside
// TypeLoc never has a deduced type. https://llvm.org/PR42914
Outer.add(DT->getDeducedType(), Flags | Rel::Underlying);
}
void VisitTypedefType(const TypedefType *TT) {
Outer.add(TT->getDecl(), Flags);
}
void
VisitTemplateSpecializationType(const TemplateSpecializationType *TST) {
// Have to handle these case-by-case.
// templated type aliases: there's no specialized/instantiated using
// decl to point to. So try to find a decl for the underlying type
// (after substitution), and failing that point to the (templated) using
// decl.
if (TST->isTypeAlias()) {
Outer.add(TST->getAliasedType(), Flags | Rel::Underlying);
// Don't *traverse* the alias, which would result in traversing the
// template of the underlying type.
Outer.report(
TST->getTemplateName().getAsTemplateDecl()->getTemplatedDecl(),
Flags | Rel::Alias | Rel::TemplatePattern);
}
// specializations of template template parameters aren't instantiated
// into decls, so they must refer to the parameter itself.
else if (const auto *Parm =
llvm::dyn_cast_or_null<TemplateTemplateParmDecl>(
TST->getTemplateName().getAsTemplateDecl()))
Outer.add(Parm, Flags);
// class template specializations have a (specialized) CXXRecordDecl.
else if (const CXXRecordDecl *RD = TST->getAsCXXRecordDecl())
Outer.add(RD, Flags); // add(Decl) will despecialize if needed.
else {
// fallback: the (un-specialized) declaration from primary template.
if (auto *TD = TST->getTemplateName().getAsTemplateDecl())
Outer.add(TD->getTemplatedDecl(), Flags | Rel::TemplatePattern);
}
}
void VisitTemplateTypeParmType(const TemplateTypeParmType *TTPT) {
Outer.add(TTPT->getDecl(), Flags);
}
void VisitObjCInterfaceType(const ObjCInterfaceType *OIT) {
Outer.add(OIT->getDecl(), Flags);
}
void VisitObjCObjectType(const ObjCObjectType *OOT) {
// FIXME: ObjCObjectTypeLoc has no children for the protocol list, so
// there is no node in id<Foo> that refers to ObjCProtocolDecl Foo.
if (OOT->isObjCQualifiedId() && OOT->getNumProtocols() == 1)
Outer.add(OOT->getProtocol(0), Flags);
}
};
Visitor(*this, Flags).Visit(T.getTypePtr());
}
void add(const NestedNameSpecifier *NNS, RelSet Flags) {
if (!NNS)
return;
debug(*NNS, Flags);
switch (NNS->getKind()) {
case NestedNameSpecifier::Identifier:
return;
case NestedNameSpecifier::Namespace:
add(NNS->getAsNamespace(), Flags);
return;
case NestedNameSpecifier::NamespaceAlias:
add(NNS->getAsNamespaceAlias(), Flags);
return;
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
add(QualType(NNS->getAsType(), 0), Flags);
return;
case NestedNameSpecifier::Global:
// This should be TUDecl, but we can't get a pointer to it!
return;
case NestedNameSpecifier::Super:
add(NNS->getAsRecordDecl(), Flags);
return;
}
llvm_unreachable("unhandled NestedNameSpecifier::SpecifierKind");
}
void add(const CXXCtorInitializer *CCI, RelSet Flags) {
if (!CCI)
return;
debug(*CCI, Flags);
if (CCI->isAnyMemberInitializer())
add(CCI->getAnyMember(), Flags);
// Constructor calls contain a TypeLoc node, so we don't handle them here.
}
};
} // namespace
llvm::SmallVector<std::pair<const Decl *, DeclRelationSet>, 1>
allTargetDecls(const ast_type_traits::DynTypedNode &N) {
dlog("allTargetDecls({0})", nodeToString(N));
TargetFinder Finder;
DeclRelationSet Flags;
if (const Decl *D = N.get<Decl>())
Finder.add(D, Flags);
else if (const Stmt *S = N.get<Stmt>())
Finder.add(S, Flags);
else if (const NestedNameSpecifierLoc *NNSL = N.get<NestedNameSpecifierLoc>())
Finder.add(NNSL->getNestedNameSpecifier(), Flags);
else if (const NestedNameSpecifier *NNS = N.get<NestedNameSpecifier>())
Finder.add(NNS, Flags);
else if (const TypeLoc *TL = N.get<TypeLoc>())
Finder.add(TL->getType(), Flags);
else if (const QualType *QT = N.get<QualType>())
Finder.add(*QT, Flags);
else if (const CXXCtorInitializer *CCI = N.get<CXXCtorInitializer>())
Finder.add(CCI, Flags);
return {Finder.Decls.begin(), Finder.Decls.end()};
}
llvm::SmallVector<const Decl *, 1>
targetDecl(const ast_type_traits::DynTypedNode &N, DeclRelationSet Mask) {
llvm::SmallVector<const Decl *, 1> Result;
for (const auto &Entry : allTargetDecls(N)) {
if (!(Entry.second & ~Mask))
Result.push_back(Entry.first);
}
return Result;
}
namespace {
/// Find declarations explicitly referenced in the source code defined by \p N.
/// For templates, will prefer to return a template instantiation whenever
/// possible. However, can also return a template pattern if the specialization
/// cannot be picked, e.g. in dependent code or when there is no corresponding
/// Decl for a template instantitation, e.g. for templated using decls:
/// template <class T> using Ptr = T*;
/// Ptr<int> x;
/// ^~~ there is no Decl for 'Ptr<int>', so we return the template pattern.
llvm::SmallVector<const NamedDecl *, 1>
explicitReferenceTargets(DynTypedNode N, DeclRelationSet Mask = {}) {
assert(!(Mask & (DeclRelation::TemplatePattern |
DeclRelation::TemplateInstantiation)) &&
"explicitRefenceTargets handles templates on its own");
auto Decls = allTargetDecls(N);
// We prefer to return template instantiation, but fallback to template
// pattern if instantiation is not available.
Mask |= DeclRelation::TemplatePattern | DeclRelation::TemplateInstantiation;
llvm::SmallVector<const NamedDecl *, 1> TemplatePatterns;
llvm::SmallVector<const NamedDecl *, 1> Targets;
bool SeenTemplateInstantiations = false;
for (auto &D : Decls) {
if (D.second & ~Mask)
continue;
if (D.second & DeclRelation::TemplatePattern) {
TemplatePatterns.push_back(llvm::cast<NamedDecl>(D.first));
continue;
}
if (D.second & DeclRelation::TemplateInstantiation)
SeenTemplateInstantiations = true;
Targets.push_back(llvm::cast<NamedDecl>(D.first));
}
if (!SeenTemplateInstantiations)
Targets.insert(Targets.end(), TemplatePatterns.begin(),
TemplatePatterns.end());
return Targets;
}
llvm::SmallVector<ReferenceLoc, 2> refInDecl(const Decl *D) {
struct Visitor : ConstDeclVisitor<Visitor> {
llvm::SmallVector<ReferenceLoc, 2> Refs;
void VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
// We want to keep it as non-declaration references, as the
// "using namespace" declaration doesn't have a name.
Refs.push_back(ReferenceLoc{D->getQualifierLoc(),
D->getIdentLocation(),
/*IsDecl=*/false,
{D->getNominatedNamespaceAsWritten()}});
}
void VisitUsingDecl(const UsingDecl *D) {
// "using ns::identifer;" is a non-declaration reference.
Refs.push_back(
ReferenceLoc{D->getQualifierLoc(), D->getLocation(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(*D),
DeclRelation::Underlying)});
}
void VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
// For namespace alias, "namespace Foo = Target;", we add two references.
// Add a declaration reference for Foo.
VisitNamedDecl(D);
// Add a non-declaration reference for Target.
Refs.push_back(ReferenceLoc{D->getQualifierLoc(),
D->getTargetNameLoc(),
/*IsDecl=*/false,
{D->getAliasedNamespace()}});
}
void VisitNamedDecl(const NamedDecl *ND) {
// FIXME: decide on how to surface destructors when we need them.
if (llvm::isa<CXXDestructorDecl>(ND))
return;
// Filter anonymous decls, name location will point outside the name token
// and the clients are not prepared to handle that.
if (ND->getDeclName().isIdentifier() &&
!ND->getDeclName().getAsIdentifierInfo())
return;
Refs.push_back(ReferenceLoc{getQualifierLoc(*ND),
ND->getLocation(),
/*IsDecl=*/true,
{ND}});
}
};
Visitor V;
V.Visit(D);
return V.Refs;
}
llvm::SmallVector<ReferenceLoc, 2> refInExpr(const Expr *E) {
struct Visitor : ConstStmtVisitor<Visitor> {
// FIXME: handle more complicated cases, e.g. ObjC, designated initializers.
llvm::SmallVector<ReferenceLoc, 2> Refs;
void VisitDeclRefExpr(const DeclRefExpr *E) {
Refs.push_back(ReferenceLoc{E->getQualifierLoc(),
E->getNameInfo().getLoc(),
/*IsDecl=*/false,
{E->getFoundDecl()}});
}
void VisitMemberExpr(const MemberExpr *E) {
Refs.push_back(ReferenceLoc{E->getQualifierLoc(),
E->getMemberNameInfo().getLoc(),
/*IsDecl=*/false,
{E->getFoundDecl()}});
}
void VisitOverloadExpr(const OverloadExpr *E) {
Refs.push_back(ReferenceLoc{E->getQualifierLoc(),
E->getNameInfo().getLoc(),
/*IsDecl=*/false,
llvm::SmallVector<const NamedDecl *, 1>(
E->decls().begin(), E->decls().end())});
}
};
Visitor V;
V.Visit(E);
return V.Refs;
}
llvm::SmallVector<ReferenceLoc, 2> refInTypeLoc(TypeLoc L) {
struct Visitor : TypeLocVisitor<Visitor> {
llvm::Optional<ReferenceLoc> Ref;
void VisitElaboratedTypeLoc(ElaboratedTypeLoc L) {
// We only know about qualifier, rest if filled by inner locations.
Visit(L.getNamedTypeLoc().getUnqualifiedLoc());
// Fill in the qualifier.
if (!Ref)
return;
assert(!Ref->Qualifier.hasQualifier() && "qualifier already set");
Ref->Qualifier = L.getQualifierLoc();
}
void VisitTagTypeLoc(TagTypeLoc L) {
Ref = ReferenceLoc{NestedNameSpecifierLoc(),
L.getNameLoc(),
/*IsDecl=*/false,
{L.getDecl()}};
}
void VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc L) {
Ref = ReferenceLoc{NestedNameSpecifierLoc(),
L.getNameLoc(),
/*IsDecl=*/false,
{L.getDecl()}};
}
void VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc L) {
// We must ensure template type aliases are included in results if they
// were written in the source code, e.g. in
// template <class T> using valias = vector<T>;
// ^valias<int> x;
// 'explicitReferenceTargets' will return:
// 1. valias with mask 'Alias'.
// 2. 'vector<int>' with mask 'Underlying'.
// we want to return only #1 in this case.
Ref = ReferenceLoc{
NestedNameSpecifierLoc(), L.getTemplateNameLoc(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(L.getType()),
DeclRelation::Alias)};
}
void VisitDeducedTemplateSpecializationTypeLoc(
DeducedTemplateSpecializationTypeLoc L) {
Ref = ReferenceLoc{
NestedNameSpecifierLoc(), L.getNameLoc(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(L.getType()),
DeclRelation::Alias)};
}
void VisitDependentTemplateSpecializationTypeLoc(
DependentTemplateSpecializationTypeLoc L) {
Ref = ReferenceLoc{
L.getQualifierLoc(), L.getTemplateNameLoc(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(L.getType()))};
}
void VisitDependentNameTypeLoc(DependentNameTypeLoc L) {
Ref = ReferenceLoc{
L.getQualifierLoc(), L.getNameLoc(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(L.getType()))};
}
void VisitTypedefTypeLoc(TypedefTypeLoc L) {
Ref = ReferenceLoc{NestedNameSpecifierLoc(),
L.getNameLoc(),
/*IsDecl=*/false,
{L.getTypedefNameDecl()}};
}
};
Visitor V;
V.Visit(L.getUnqualifiedLoc());
if (!V.Ref)
return {};
return {*V.Ref};
}
class ExplicitReferenceColletor
: public RecursiveASTVisitor<ExplicitReferenceColletor> {
public:
ExplicitReferenceColletor(llvm::function_ref<void(ReferenceLoc)> Out)
: Out(Out) {
assert(Out);
}
bool VisitTypeLoc(TypeLoc TTL) {
if (TypeLocsToSkip.count(TTL.getBeginLoc().getRawEncoding()))
return true;
visitNode(DynTypedNode::create(TTL));
return true;
}
bool TraverseElaboratedTypeLoc(ElaboratedTypeLoc L) {
// ElaboratedTypeLoc will reports information for its inner type loc.
// Otherwise we loose information about inner types loc's qualifier.
TypeLoc Inner = L.getNamedTypeLoc().getUnqualifiedLoc();
TypeLocsToSkip.insert(Inner.getBeginLoc().getRawEncoding());
return RecursiveASTVisitor::TraverseElaboratedTypeLoc(L);
}
bool VisitExpr(Expr *E) {
visitNode(DynTypedNode::create(*E));
return true;
}
// We re-define Traverse*, since there's no corresponding Visit*.
// TemplateArgumentLoc is the only way to get locations for references to
// template template parameters.
bool TraverseTemplateArgumentLoc(TemplateArgumentLoc A) {
switch (A.getArgument().getKind()) {
case TemplateArgument::Template:
case TemplateArgument::TemplateExpansion:
reportReference(ReferenceLoc{A.getTemplateQualifierLoc(),
A.getTemplateNameLoc(),
/*IsDecl=*/false,
{A.getArgument()
.getAsTemplateOrTemplatePattern()
.getAsTemplateDecl()}},
DynTypedNode::create(A.getArgument()));
break;
case TemplateArgument::Declaration:
break; // FIXME: can this actually happen in TemplateArgumentLoc?
case TemplateArgument::Integral:
case TemplateArgument::Null:
case TemplateArgument::NullPtr:
break; // no references.
case TemplateArgument::Pack:
case TemplateArgument::Type:
case TemplateArgument::Expression:
break; // Handled by VisitType and VisitExpression.
};
return RecursiveASTVisitor::TraverseTemplateArgumentLoc(A);
}
bool VisitDecl(Decl *D) {
visitNode(DynTypedNode::create(*D));
return true;
}
// We have to use Traverse* because there is no corresponding Visit*.
bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc L) {
if (!L.getNestedNameSpecifier())
return true;
visitNode(DynTypedNode::create(L));
// Inner type is missing information about its qualifier, skip it.
if (auto TL = L.getTypeLoc())
TypeLocsToSkip.insert(TL.getBeginLoc().getRawEncoding());
return RecursiveASTVisitor::TraverseNestedNameSpecifierLoc(L);
}
bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
visitNode(DynTypedNode::create(*Init));
return RecursiveASTVisitor::TraverseConstructorInitializer(Init);
}
private:
/// Obtain information about a reference directly defined in \p N. Does not
/// recurse into child nodes, e.g. do not expect references for constructor
/// initializers
///
/// Any of the fields in the returned structure can be empty, but not all of
/// them, e.g.
/// - for implicitly generated nodes (e.g. MemberExpr from range-based-for),
/// source location information may be missing,
/// - for dependent code, targets may be empty.
///
/// (!) For the purposes of this function declarations are not considered to
/// be references. However, declarations can have references inside them,
/// e.g. 'namespace foo = std' references namespace 'std' and this
/// function will return the corresponding reference.
llvm::SmallVector<ReferenceLoc, 2> explicitReference(DynTypedNode N) {
if (auto *D = N.get<Decl>())
return refInDecl(D);
if (auto *E = N.get<Expr>())
return refInExpr(E);
if (auto *NNSL = N.get<NestedNameSpecifierLoc>()) {
// (!) 'DeclRelation::Alias' ensures we do not loose namespace aliases.
return {ReferenceLoc{
NNSL->getPrefix(), NNSL->getLocalBeginLoc(), false,
explicitReferenceTargets(
DynTypedNode::create(*NNSL->getNestedNameSpecifier()),
DeclRelation::Alias)}};
}
if (const TypeLoc *TL = N.get<TypeLoc>())
return refInTypeLoc(*TL);
if (const CXXCtorInitializer *CCI = N.get<CXXCtorInitializer>()) {
// Other type initializers (e.g. base initializer) are handled by visiting
// the typeLoc.
if (CCI->isAnyMemberInitializer()) {
return {ReferenceLoc{NestedNameSpecifierLoc(),
CCI->getMemberLocation(),
/*IsDecl=*/false,
{CCI->getAnyMember()}}};
}
}
// We do not have location information for other nodes (QualType, etc)
return {};
}
void visitNode(DynTypedNode N) {
for (const auto &R : explicitReference(N))
reportReference(R, N);
}
void reportReference(const ReferenceLoc &Ref, DynTypedNode N) {
// Our promise is to return only references from the source code. If we lack
// location information, skip these nodes.
// Normally this should not happen in practice, unless there are bugs in the
// traversals or users started the traversal at an implicit node.
if (Ref.NameLoc.isInvalid()) {
dlog("invalid location at node {0}", nodeToString(N));
return;
}
Out(Ref);
}
llvm::function_ref<void(ReferenceLoc)> Out;
/// TypeLocs starting at these locations must be skipped, see
/// TraverseElaboratedTypeSpecifierLoc for details.
llvm::DenseSet</*SourceLocation*/ unsigned> TypeLocsToSkip;
};
} // namespace
void findExplicitReferences(const Stmt *S,
llvm::function_ref<void(ReferenceLoc)> Out) {
assert(S);
ExplicitReferenceColletor(Out).TraverseStmt(const_cast<Stmt *>(S));
}
void findExplicitReferences(const Decl *D,
llvm::function_ref<void(ReferenceLoc)> Out) {
assert(D);
ExplicitReferenceColletor(Out).TraverseDecl(const_cast<Decl *>(D));
}
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, DeclRelation R) {
switch (R) {
#define REL_CASE(X) \
case DeclRelation::X: \
return OS << #X;
REL_CASE(Alias);
REL_CASE(Underlying);
REL_CASE(TemplateInstantiation);
REL_CASE(TemplatePattern);
#undef REL_CASE
}
llvm_unreachable("Unhandled DeclRelation enum");
}
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, DeclRelationSet RS) {
const char *Sep = "";
for (unsigned I = 0; I < RS.S.size(); ++I) {
if (RS.S.test(I)) {
OS << Sep << static_cast<DeclRelation>(I);
Sep = "|";
}
}
return OS;
}
llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, ReferenceLoc R) {
// note we cannot print R.NameLoc without a source manager.
OS << "targets = {";
bool First = true;
for (const NamedDecl *T : R.Targets) {
if (!First)
OS << ", ";
else
First = false;
OS << printQualifiedName(*T) << printTemplateSpecializationArgs(*T);
}
OS << "}";
if (R.Qualifier) {
OS << ", qualifier = '";
R.Qualifier.getNestedNameSpecifier()->print(OS,
PrintingPolicy(LangOptions()));
OS << "'";
}
if (R.IsDecl)
OS << ", decl";
return OS;
}
} // namespace clangd
} // namespace clang