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 "support/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/ExprConcepts.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/AST/TypeVisitor.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/Specifiers.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 <iterator>
#include <utility>
#include <vector>
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 = std::string(N.getNodeKind().asStringRef());
{
llvm::raw_string_ostream OS(S);
OS << ": ";
N.print(OS, PrintingPolicy(LangOptions()));
}
std::replace(S.begin(), S.end(), '\n', ' ');
return S;
}
// Helper function for getMembersReferencedViaDependentName()
// which takes a possibly-dependent type `T` and heuristically
// resolves it to a CXXRecordDecl in which we can try name lookup.
CXXRecordDecl *resolveTypeToRecordDecl(const Type *T) {
assert(T);
if (const auto *RT = T->getAs<RecordType>())
return dyn_cast<CXXRecordDecl>(RT->getDecl());
if (const auto *ICNT = T->getAs<InjectedClassNameType>())
T = ICNT->getInjectedSpecializationType().getTypePtrOrNull();
if (!T)
return nullptr;
const auto *TST = T->getAs<TemplateSpecializationType>();
if (!TST)
return nullptr;
const ClassTemplateDecl *TD = dyn_cast_or_null<ClassTemplateDecl>(
TST->getTemplateName().getAsTemplateDecl());
if (!TD)
return nullptr;
return TD->getTemplatedDecl();
}
// Given a tag-decl type and a member name, heuristically resolve the
// name to one or more declarations.
// The current heuristic is simply to look up the name in the primary
// template. This is a heuristic because the template could potentially
// have specializations that declare different members.
// Multiple declarations could be returned if the name is overloaded
// (e.g. an overloaded method in the primary template).
// This heuristic will give the desired answer in many cases, e.g.
// for a call to vector<T>::size().
// The name to look up is provided in the form of a factory that takes
// an ASTContext, because an ASTContext may be needed to obtain the
// name (e.g. if it's an operator name), but the caller may not have
// access to an ASTContext.
std::vector<const NamedDecl *> getMembersReferencedViaDependentName(
const Type *T,
llvm::function_ref<DeclarationName(ASTContext &)> NameFactory,
llvm::function_ref<bool(const NamedDecl *ND)> Filter) {
if (!T)
return {};
if (auto *ET = T->getAs<EnumType>()) {
auto Result =
ET->getDecl()->lookup(NameFactory(ET->getDecl()->getASTContext()));
return {Result.begin(), Result.end()};
}
if (auto *RD = resolveTypeToRecordDecl(T)) {
if (!RD->hasDefinition())
return {};
RD = RD->getDefinition();
DeclarationName Name = NameFactory(RD->getASTContext());
return RD->lookupDependentName(Name, Filter);
}
return {};
}
const auto NonStaticFilter = [](const NamedDecl *D) {
return D->isCXXInstanceMember();
};
const auto StaticFilter = [](const NamedDecl *D) {
return !D->isCXXInstanceMember();
};
const auto ValueFilter = [](const NamedDecl *D) { return isa<ValueDecl>(D); };
// Given the type T of a dependent expression that appears of the LHS of a
// "->", heuristically find a corresponding pointee type in whose scope we
// could look up the name appearing on the RHS.
const Type *getPointeeType(const Type *T) {
if (!T)
return nullptr;
if (T->isPointerType()) {
return T->getAs<PointerType>()->getPointeeType().getTypePtrOrNull();
}
// Try to handle smart pointer types.
// Look up operator-> in the primary template. If we find one, it's probably a
// smart pointer type.
auto ArrowOps = getMembersReferencedViaDependentName(
T,
[](ASTContext &Ctx) {
return Ctx.DeclarationNames.getCXXOperatorName(OO_Arrow);
},
NonStaticFilter);
if (ArrowOps.empty())
return nullptr;
// Getting the return type of the found operator-> method decl isn't useful,
// because we discarded template arguments to perform lookup in the primary
// template scope, so the return type would just have the form U* where U is a
// template parameter type.
// Instead, just handle the common case where the smart pointer type has the
// form of SmartPtr<X, ...>, and assume X is the pointee type.
auto *TST = T->getAs<TemplateSpecializationType>();
if (!TST)
return nullptr;
if (TST->getNumArgs() == 0)
return nullptr;
const TemplateArgument &FirstArg = TST->getArg(0);
if (FirstArg.getKind() != TemplateArgument::Type)
return nullptr;
return FirstArg.getAsType().getTypePtrOrNull();
}
// Forward declaration, needed as this function is mutually recursive
// with resolveExprToDecls.
const Type *resolveExprToType(const Expr *E);
// Try to heuristically resolve a possibly-dependent expression `E` to one
// or more declarations that it likely references.
std::vector<const NamedDecl *> resolveExprToDecls(const Expr *E) {
if (const auto *ME = dyn_cast<CXXDependentScopeMemberExpr>(E)) {
const Type *BaseType = ME->getBaseType().getTypePtrOrNull();
if (ME->isArrow()) {
BaseType = getPointeeType(BaseType);
}
if (!BaseType)
return {};
if (const auto *BT = BaseType->getAs<BuiltinType>()) {
// If BaseType is the type of a dependent expression, it's just
// represented as BultinType::Dependent which gives us no information. We
// can get further by analyzing the depedent expression.
Expr *Base = ME->isImplicitAccess() ? nullptr : ME->getBase();
if (Base && BT->getKind() == BuiltinType::Dependent) {
BaseType = resolveExprToType(Base);
}
}
return getMembersReferencedViaDependentName(
BaseType, [ME](ASTContext &) { return ME->getMember(); },
NonStaticFilter);
}
if (const auto *RE = dyn_cast<DependentScopeDeclRefExpr>(E)) {
return getMembersReferencedViaDependentName(
RE->getQualifier()->getAsType(),
[RE](ASTContext &) { return RE->getDeclName(); }, StaticFilter);
}
if (const auto *CE = dyn_cast<CallExpr>(E)) {
const auto *CalleeType = resolveExprToType(CE->getCallee());
if (!CalleeType)
return {};
if (const auto *FnTypePtr = CalleeType->getAs<PointerType>())
CalleeType = FnTypePtr->getPointeeType().getTypePtr();
if (const FunctionType *FnType = CalleeType->getAs<FunctionType>()) {
if (const auto *D =
resolveTypeToRecordDecl(FnType->getReturnType().getTypePtr())) {
return {D};
}
}
}
if (const auto *ME = dyn_cast<MemberExpr>(E))
return {ME->getMemberDecl()};
if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
return {DRE->getFoundDecl()};
return {};
}
// Try to heuristically resolve the type of a possibly-dependent expression `E`.
const Type *resolveExprToType(const Expr *E) {
std::vector<const NamedDecl *> Decls = resolveExprToDecls(E);
if (Decls.size() != 1) // Names an overload set -- just bail.
return nullptr;
if (const auto *TD = dyn_cast<TypeDecl>(Decls[0])) {
return TD->getTypeForDecl();
} else if (const auto *VD = dyn_cast<ValueDecl>(Decls[0])) {
return VD->getType().getTypePtrOrNull();
}
return nullptr;
}
const NamedDecl *getTemplatePattern(const NamedDecl *D) {
if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(D)) {
if (const auto *Result = CRD->getTemplateInstantiationPattern())
return Result;
// getTemplateInstantiationPattern returns null if the Specialization is
// incomplete (e.g. the type didn't need to be complete), fall back to the
// primary template.
if (CRD->getTemplateSpecializationKind() == TSK_Undeclared)
if (const auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(CRD))
return Spec->getSpecializedTemplate()->getTemplatedDecl();
} 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)) {
if (const auto *Parent = llvm::dyn_cast<NamedDecl>(D->getDeclContext()))
if (const DeclContext *ParentPat =
dyn_cast_or_null<DeclContext>(getTemplatePattern(Parent)))
for (const NamedDecl *BaseND : ParentPat->lookup(D->getDeclName()))
if (!BaseND->isImplicit() && BaseND->getKind() == D->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;
}
// 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.
// We currently handle DependentScopeDeclRefExpr and
// CXXDependentScopeMemberExpr, but some other constructs remain to be handled:
// - DependentTemplateSpecializationType,
// - DependentNameType
// - UnresolvedUsingTypenameDecl
struct TargetFinder {
using RelSet = DeclRelationSet;
using Rel = DeclRelation;
private:
llvm::SmallDenseMap<const NamedDecl *,
std::pair<RelSet, /*InsertionOrder*/ size_t>>
Decls;
RelSet Flags;
template <typename T> void debug(T &Node, RelSet Flags) {
dlog("visit [{0}] {1}", Flags,
nodeToString(ast_type_traits::DynTypedNode::create(Node)));
}
void report(const NamedDecl *D, RelSet Flags) {
dlog("--> [{0}] {1}", Flags,
nodeToString(ast_type_traits::DynTypedNode::create(*D)));
auto It = Decls.try_emplace(D, std::make_pair(Flags, Decls.size()));
// If already exists, update the flags.
if (!It.second)
It.first->second.first |= Flags;
}
public:
llvm::SmallVector<std::pair<const NamedDecl *, RelSet>, 1> takeDecls() const {
using ValTy = std::pair<const NamedDecl *, RelSet>;
llvm::SmallVector<ValTy, 1> Result;
Result.resize(Decls.size());
for (const auto &Elem : Decls)
Result[Elem.second.second] = {Elem.first, Elem.second.first};
return Result;
}
void add(const Decl *Dcl, RelSet Flags) {
const NamedDecl *D = llvm::dyn_cast_or_null<NamedDecl>(Dcl);
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 UnresolvedUsingValueDecl *UUVD =
dyn_cast<UnresolvedUsingValueDecl>(D)) {
for (const NamedDecl *Target : getMembersReferencedViaDependentName(
UUVD->getQualifier()->getAsType(),
[UUVD](ASTContext &) { return UUVD->getNameInfo().getName(); },
ValueFilter)) {
add(Target, 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.
} else if (const auto *DG = dyn_cast<CXXDeductionGuideDecl>(D)) {
D = DG->getDeducedTemplate();
} else if (const ObjCImplementationDecl *IID =
dyn_cast<ObjCImplementationDecl>(D)) {
// Treat ObjC{Interface,Implementation}Decl as if they were a decl/def
// pair as long as the interface isn't implicit.
if (const auto *CID = IID->getClassInterface())
if (const auto *DD = CID->getDefinition())
if (!DD->isImplicitInterfaceDecl())
D = DD;
} else if (const ObjCCategoryImplDecl *CID =
dyn_cast<ObjCCategoryImplDecl>(D)) {
// Treat ObjC{Category,CategoryImpl}Decl as if they were a decl/def pair.
D = CID->getCategoryDecl();
}
if (!D)
return;
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 VisitCallExpr(const CallExpr *CE) {
Outer.add(CE->getCalleeDecl(), Flags);
}
void VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E) {
Outer.add(E->getNamedConcept(), 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 VisitSizeOfPackExpr(const SizeOfPackExpr *SE) {
Outer.add(SE->getPack(), 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 VisitGotoStmt(const GotoStmt *Goto) {
if (auto *LabelDecl = Goto->getLabel())
Outer.add(LabelDecl, Flags);
}
void VisitLabelStmt(const LabelStmt *Label) {
if (auto *LabelDecl = Label->getDecl())
Outer.add(LabelDecl, Flags);
}
void
VisitCXXDependentScopeMemberExpr(const CXXDependentScopeMemberExpr *E) {
for (const NamedDecl *D : resolveExprToDecls(E)) {
Outer.add(D, Flags);
}
}
void VisitDependentScopeDeclRefExpr(const DependentScopeDeclRefExpr *E) {
for (const NamedDecl *D : resolveExprToDecls(E)) {
Outer.add(D, Flags);
}
}
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);
}
void VisitOpaqueValueExpr(const OpaqueValueExpr *OVE) {
Outer.add(OVE->getSourceExpr(), Flags);
}
void VisitPseudoObjectExpr(const PseudoObjectExpr *POE) {
Outer.add(POE->getSyntacticForm(), Flags);
}
void VisitCXXNewExpr(const CXXNewExpr *CNE) {
Outer.add(CNE->getOperatorNew(), Flags);
}
void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE) {
Outer.add(CDE->getOperatorDelete(), 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 VisitElaboratedType(const ElaboratedType *ET) {
Outer.add(ET->desugar(), Flags);
}
void VisitInjectedClassNameType(const InjectedClassNameType *ICNT) {
Outer.add(ICNT->getDecl(), 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 VisitDeducedTemplateSpecializationType(
const DeducedTemplateSpecializationType *DTST) {
// FIXME: This is a workaround for https://llvm.org/PR42914,
// which is causing DTST->getDeducedType() to be empty. We
// fall back to the template pattern and miss the instantiation
// even when it's known in principle. Once that bug is fixed,
// this method can be removed (the existing handling in
// VisitDeducedType() is sufficient).
if (auto *TD = DTST->getTemplateName().getAsTemplateDecl())
Outer.add(TD->getTemplatedDecl(), Flags | Rel::TemplatePattern);
}
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.
}
void add(const TemplateArgument &Arg, RelSet Flags) {
// Only used for template template arguments.
// For type and non-type template arguments, SelectionTree
// will hit a more specific node (e.g. a TypeLoc or a
// DeclRefExpr).
if (Arg.getKind() == TemplateArgument::Template ||
Arg.getKind() == TemplateArgument::TemplateExpansion) {
if (TemplateDecl *TD = Arg.getAsTemplate().getAsTemplateDecl()) {
report(TD, Flags);
}
}
}
};
} // namespace
llvm::SmallVector<std::pair<const NamedDecl *, 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);
else if (const TemplateArgumentLoc *TAL = N.get<TemplateArgumentLoc>())
Finder.add(TAL->getArgument(), Flags);
return Finder.takeDecls();
}
llvm::SmallVector<const NamedDecl *, 1>
targetDecl(const ast_type_traits::DynTypedNode &N, DeclRelationSet Mask) {
llvm::SmallVector<const NamedDecl *, 1> Result;
for (const auto &Entry : allTargetDecls(N)) {
if (!(Entry.second & ~Mask))
Result.push_back(Entry.first);
}
return Result;
}
llvm::SmallVector<const NamedDecl *, 1>
explicitReferenceTargets(DynTypedNode N, DeclRelationSet Mask) {
assert(!(Mask & (DeclRelation::TemplatePattern |
DeclRelation::TemplateInstantiation)) &&
"explicitReferenceTargets 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(D.first);
continue;
}
if (D.second & DeclRelation::TemplateInstantiation)
SeenTemplateInstantiations = true;
Targets.push_back(D.first);
}
if (!SeenTemplateInstantiations)
Targets.insert(Targets.end(), TemplatePatterns.begin(),
TemplatePatterns.end());
return Targets;
}
namespace {
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) {
2020-01-04 23:28:41 +08:00
// "using ns::identifier;" 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) {
// We choose to ignore {Class, Function, Var, TypeAlias}TemplateDecls. As
// as their underlying decls, covering the same range, will be visited.
if (llvm::isa<ClassTemplateDecl>(ND) ||
llvm::isa<FunctionTemplateDecl>(ND) ||
llvm::isa<VarTemplateDecl>(ND) ||
llvm::isa<TypeAliasTemplateDecl>(ND))
return;
// 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}});
}
void VisitCXXDeductionGuideDecl(const CXXDeductionGuideDecl *DG) {
// The class template name in a deduction guide targets the class
// template.
Refs.push_back(ReferenceLoc{DG->getQualifierLoc(),
DG->getNameInfo().getLoc(),
/*IsDecl=*/false,
{DG->getDeducedTemplate()}});
}
};
Visitor V;
V.Visit(D);
return V.Refs;
}
llvm::SmallVector<ReferenceLoc, 2> refInStmt(const Stmt *S) {
struct Visitor : ConstStmtVisitor<Visitor> {
// FIXME: handle more complicated cases: more ObjC, designated initializers.
llvm::SmallVector<ReferenceLoc, 2> Refs;
void VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E) {
Refs.push_back(ReferenceLoc{E->getNestedNameSpecifierLoc(),
E->getConceptNameLoc(),
/*IsDecl=*/false,
{E->getNamedConcept()}});
}
void VisitDeclRefExpr(const DeclRefExpr *E) {
Refs.push_back(ReferenceLoc{E->getQualifierLoc(),
E->getNameInfo().getLoc(),
/*IsDecl=*/false,
{E->getFoundDecl()}});
}
void VisitDependentScopeDeclRefExpr(const DependentScopeDeclRefExpr *E) {
Refs.push_back(ReferenceLoc{
E->getQualifierLoc(), E->getNameInfo().getLoc(), /*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(*E), {})});
}
void VisitMemberExpr(const MemberExpr *E) {
// Skip destructor calls to avoid duplication: TypeLoc within will be
// visited separately.
if (llvm::dyn_cast<CXXDestructorDecl>(E->getFoundDecl().getDecl()))
return;
Refs.push_back(ReferenceLoc{E->getQualifierLoc(),
E->getMemberNameInfo().getLoc(),
/*IsDecl=*/false,
{E->getFoundDecl()}});
}
void
VisitCXXDependentScopeMemberExpr(const CXXDependentScopeMemberExpr *E) {
Refs.push_back(
ReferenceLoc{E->getQualifierLoc(), E->getMemberNameInfo().getLoc(),
/*IsDecl=*/false,
explicitReferenceTargets(DynTypedNode::create(*E), {})});
}
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())});
}
void VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(),
E->getPackLoc(),
/*IsDecl=*/false,
{E->getPack()}});
}
void VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *E) {
Refs.push_back(ReferenceLoc{
NestedNameSpecifierLoc(), E->getLocation(),
/*IsDecl=*/false,
// Select the getter, setter, or @property depending on the call.
explicitReferenceTargets(DynTypedNode::create(*E), {})});
}
void VisitDesignatedInitExpr(const DesignatedInitExpr *DIE) {
for (const DesignatedInitExpr::Designator &D : DIE->designators()) {
if (!D.isFieldDesignator())
continue;
llvm::SmallVector<const NamedDecl *, 1> Targets;
if (D.getField())
Targets.push_back(D.getField());
Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(), D.getFieldLoc(),
/*IsDecl=*/false, std::move(Targets)});
}
}
void VisitGotoStmt(const GotoStmt *GS) {
llvm::SmallVector<const NamedDecl *, 1> Targets;
if (const auto *L = GS->getLabel())
Targets.push_back(L);
Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(), GS->getLabelLoc(),
/*IsDecl=*/false, std::move(Targets)});
}
void VisitLabelStmt(const LabelStmt *LS) {
Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(),
LS->getIdentLoc(),
/*IsDecl=*/true,
{LS->getDecl()}});
}
};
Visitor V;
V.Visit(S);
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 VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
Ref = ReferenceLoc{NestedNameSpecifierLoc(),
TL.getNameLoc(),
/*IsDecl=*/false,
{TL.getDecl()}};
}
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 ExplicitReferenceCollector
: public RecursiveASTVisitor<ExplicitReferenceCollector> {
public:
ExplicitReferenceCollector(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 VisitStmt(Stmt *S) {
visitNode(DynTypedNode::create(*S));
return true;
}
bool TraverseOpaqueValueExpr(OpaqueValueExpr *OVE) {
visitNode(DynTypedNode::create(*OVE));
// Not clear why the source expression is skipped by default...
// FIXME: can we just make RecursiveASTVisitor do this?
return RecursiveASTVisitor::TraverseStmt(OVE->getSourceExpr());
}
bool TraversePseudoObjectExpr(PseudoObjectExpr *POE) {
visitNode(DynTypedNode::create(*POE));
// Traverse only the syntactic form to find the *written* references.
// (The semantic form also contains lots of duplication)
return RecursiveASTVisitor::TraverseStmt(POE->getSyntacticForm());
}
// 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) {
llvm::SmallVector<const NamedDecl *, 1> Targets;
switch (A.getArgument().getKind()) {
case TemplateArgument::Template:
case TemplateArgument::TemplateExpansion:
if (const auto *D = A.getArgument()
.getAsTemplateOrTemplatePattern()
.getAsTemplateDecl())
Targets.push_back(D);
reportReference(ReferenceLoc{A.getTemplateQualifierLoc(),
A.getTemplateNameLoc(),
/*IsDecl=*/false, Targets},
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 *S = N.get<Stmt>())
return refInStmt(S);
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);
ExplicitReferenceCollector(Out).TraverseStmt(const_cast<Stmt *>(S));
}
void findExplicitReferences(const Decl *D,
llvm::function_ref<void(ReferenceLoc)> Out) {
assert(D);
ExplicitReferenceCollector(Out).TraverseDecl(const_cast<Decl *>(D));
}
void findExplicitReferences(const ASTContext &AST,
llvm::function_ref<void(ReferenceLoc)> Out) {
ExplicitReferenceCollector(Out).TraverseAST(const_cast<ASTContext &>(AST));
}
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