llvm-project/clang/lib/Index/IndexBody.cpp
Ilya Biryukov 75e16fd2c6 [Index] [clangd] Support for concept declarations and requires expressions
Add support for concepts and requires expression in the clang index.
Genarate USRs for concepts.

Also change how `RecursiveASTVisitor` handles return type requirement in
requires expressions. The new code unpacks the synthetic template parameter
list used for storing the actual expression. This simplifies
implementation of the indexing. No code seems to depend on the original
traversal anyway and the synthesized template parameter list is easily
accessible from inside the requires expression if needed.

Add tests in the clangd codebase.

Fixes https://github.com/clangd/clangd/issues/1103.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D124441
2022-04-26 13:50:01 +00:00

507 lines
18 KiB
C++

//===- IndexBody.cpp - Indexing statements --------------------------------===//
//
// 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 "IndexingContext.h"
#include "clang/AST/ASTConcept.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/ExprConcepts.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Type.h"
using namespace clang;
using namespace clang::index;
namespace {
class BodyIndexer : public RecursiveASTVisitor<BodyIndexer> {
IndexingContext &IndexCtx;
const NamedDecl *Parent;
const DeclContext *ParentDC;
SmallVector<Stmt*, 16> StmtStack;
typedef RecursiveASTVisitor<BodyIndexer> base;
Stmt *getParentStmt() const {
return StmtStack.size() < 2 ? nullptr : StmtStack.end()[-2];
}
public:
BodyIndexer(IndexingContext &indexCtx,
const NamedDecl *Parent, const DeclContext *DC)
: IndexCtx(indexCtx), Parent(Parent), ParentDC(DC) { }
bool shouldWalkTypesOfTypeLocs() const { return false; }
bool dataTraverseStmtPre(Stmt *S) {
StmtStack.push_back(S);
return true;
}
bool dataTraverseStmtPost(Stmt *S) {
assert(StmtStack.back() == S);
StmtStack.pop_back();
return true;
}
bool TraverseTypeLoc(TypeLoc TL) {
IndexCtx.indexTypeLoc(TL, Parent, ParentDC);
return true;
}
bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
IndexCtx.indexNestedNameSpecifierLoc(NNS, Parent, ParentDC);
return true;
}
SymbolRoleSet getRolesForRef(const Expr *E,
SmallVectorImpl<SymbolRelation> &Relations) {
SymbolRoleSet Roles{};
assert(!StmtStack.empty() && E == StmtStack.back());
if (StmtStack.size() == 1)
return Roles;
auto It = StmtStack.end()-2;
while (isa<CastExpr>(*It) || isa<ParenExpr>(*It)) {
if (auto ICE = dyn_cast<ImplicitCastExpr>(*It)) {
if (ICE->getCastKind() == CK_LValueToRValue)
Roles |= (unsigned)(unsigned)SymbolRole::Read;
}
if (It == StmtStack.begin())
break;
--It;
}
const Stmt *Parent = *It;
if (auto BO = dyn_cast<BinaryOperator>(Parent)) {
if (BO->getOpcode() == BO_Assign && BO->getLHS()->IgnoreParenCasts() == E)
Roles |= (unsigned)SymbolRole::Write;
} else if (auto UO = dyn_cast<UnaryOperator>(Parent)) {
if (UO->isIncrementDecrementOp()) {
Roles |= (unsigned)SymbolRole::Read;
Roles |= (unsigned)SymbolRole::Write;
} else if (UO->getOpcode() == UO_AddrOf) {
Roles |= (unsigned)SymbolRole::AddressOf;
}
} else if (auto CA = dyn_cast<CompoundAssignOperator>(Parent)) {
if (CA->getLHS()->IgnoreParenCasts() == E) {
Roles |= (unsigned)SymbolRole::Read;
Roles |= (unsigned)SymbolRole::Write;
}
} else if (auto CE = dyn_cast<CallExpr>(Parent)) {
if (CE->getCallee()->IgnoreParenCasts() == E) {
addCallRole(Roles, Relations);
if (auto *ME = dyn_cast<MemberExpr>(E)) {
if (auto *CXXMD = dyn_cast_or_null<CXXMethodDecl>(ME->getMemberDecl()))
if (CXXMD->isVirtual() && !ME->hasQualifier()) {
Roles |= (unsigned)SymbolRole::Dynamic;
auto BaseTy = ME->getBase()->IgnoreImpCasts()->getType();
if (!BaseTy.isNull())
if (auto *CXXRD = BaseTy->getPointeeCXXRecordDecl())
Relations.emplace_back((unsigned)SymbolRole::RelationReceivedBy,
CXXRD);
}
}
} else if (auto CXXOp = dyn_cast<CXXOperatorCallExpr>(CE)) {
if (CXXOp->getNumArgs() > 0 && CXXOp->getArg(0)->IgnoreParenCasts() == E) {
OverloadedOperatorKind Op = CXXOp->getOperator();
if (Op == OO_Equal) {
Roles |= (unsigned)SymbolRole::Write;
} else if ((Op >= OO_PlusEqual && Op <= OO_PipeEqual) ||
Op == OO_LessLessEqual || Op == OO_GreaterGreaterEqual ||
Op == OO_PlusPlus || Op == OO_MinusMinus) {
Roles |= (unsigned)SymbolRole::Read;
Roles |= (unsigned)SymbolRole::Write;
} else if (Op == OO_Amp) {
Roles |= (unsigned)SymbolRole::AddressOf;
}
}
}
}
return Roles;
}
void addCallRole(SymbolRoleSet &Roles,
SmallVectorImpl<SymbolRelation> &Relations) {
Roles |= (unsigned)SymbolRole::Call;
if (auto *FD = dyn_cast<FunctionDecl>(ParentDC))
Relations.emplace_back((unsigned)SymbolRole::RelationCalledBy, FD);
else if (auto *MD = dyn_cast<ObjCMethodDecl>(ParentDC))
Relations.emplace_back((unsigned)SymbolRole::RelationCalledBy, MD);
}
bool VisitDeclRefExpr(DeclRefExpr *E) {
SmallVector<SymbolRelation, 4> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(E->getDecl(), E->getLocation(),
Parent, ParentDC, Roles, Relations, E);
}
bool VisitMemberExpr(MemberExpr *E) {
SourceLocation Loc = E->getMemberLoc();
if (Loc.isInvalid())
Loc = E->getBeginLoc();
SmallVector<SymbolRelation, 4> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(E->getMemberDecl(), Loc,
Parent, ParentDC, Roles, Relations, E);
}
bool indexDependentReference(
const Expr *E, const Type *T, const DeclarationNameInfo &NameInfo,
llvm::function_ref<bool(const NamedDecl *ND)> Filter) {
if (!T)
return true;
const TemplateSpecializationType *TST =
T->getAs<TemplateSpecializationType>();
if (!TST)
return true;
TemplateName TN = TST->getTemplateName();
const ClassTemplateDecl *TD =
dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
if (!TD)
return true;
CXXRecordDecl *RD = TD->getTemplatedDecl();
if (!RD->hasDefinition())
return true;
RD = RD->getDefinition();
std::vector<const NamedDecl *> Symbols =
RD->lookupDependentName(NameInfo.getName(), Filter);
// FIXME: Improve overload handling.
if (Symbols.size() != 1)
return true;
SourceLocation Loc = NameInfo.getLoc();
if (Loc.isInvalid())
Loc = E->getBeginLoc();
SmallVector<SymbolRelation, 4> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(Symbols[0], Loc, Parent, ParentDC, Roles,
Relations, E);
}
bool VisitCXXDependentScopeMemberExpr(CXXDependentScopeMemberExpr *E) {
const DeclarationNameInfo &Info = E->getMemberNameInfo();
return indexDependentReference(
E, E->getBaseType().getTypePtrOrNull(), Info,
[](const NamedDecl *D) { return D->isCXXInstanceMember(); });
}
bool VisitDependentScopeDeclRefExpr(DependentScopeDeclRefExpr *E) {
const DeclarationNameInfo &Info = E->getNameInfo();
const NestedNameSpecifier *NNS = E->getQualifier();
return indexDependentReference(
E, NNS->getAsType(), Info,
[](const NamedDecl *D) { return !D->isCXXInstanceMember(); });
}
bool VisitDesignatedInitExpr(DesignatedInitExpr *E) {
for (DesignatedInitExpr::Designator &D : llvm::reverse(E->designators())) {
if (D.isFieldDesignator() && D.getField())
return IndexCtx.handleReference(D.getField(), D.getFieldLoc(), Parent,
ParentDC, SymbolRoleSet(), {}, E);
}
return true;
}
bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
SmallVector<SymbolRelation, 4> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(E->getDecl(), E->getLocation(),
Parent, ParentDC, Roles, Relations, E);
}
bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
auto isDynamic = [](const ObjCMessageExpr *MsgE)->bool {
if (MsgE->getReceiverKind() != ObjCMessageExpr::Instance)
return false;
if (auto *RecE = dyn_cast<ObjCMessageExpr>(
MsgE->getInstanceReceiver()->IgnoreParenCasts())) {
if (RecE->getMethodFamily() == OMF_alloc)
return false;
}
return true;
};
if (ObjCMethodDecl *MD = E->getMethodDecl()) {
SymbolRoleSet Roles{};
SmallVector<SymbolRelation, 2> Relations;
addCallRole(Roles, Relations);
Stmt *Containing = getParentStmt();
auto IsImplicitProperty = [](const PseudoObjectExpr *POE) -> bool {
const auto *E = POE->getSyntacticForm();
if (const auto *BinOp = dyn_cast<BinaryOperator>(E))
E = BinOp->getLHS();
const auto *PRE = dyn_cast<ObjCPropertyRefExpr>(E);
if (!PRE)
return false;
if (PRE->isExplicitProperty())
return false;
if (const ObjCMethodDecl *Getter = PRE->getImplicitPropertyGetter()) {
// Class properties that are explicitly defined using @property
// declarations are represented implicitly as there is no ivar for
// class properties.
if (Getter->isClassMethod() &&
Getter->getCanonicalDecl()->findPropertyDecl())
return false;
}
return true;
};
bool IsPropCall = Containing && isa<PseudoObjectExpr>(Containing);
// Implicit property message sends are not 'implicit'.
if ((E->isImplicit() || IsPropCall) &&
!(IsPropCall &&
IsImplicitProperty(cast<PseudoObjectExpr>(Containing))))
Roles |= (unsigned)SymbolRole::Implicit;
if (isDynamic(E)) {
Roles |= (unsigned)SymbolRole::Dynamic;
auto addReceivers = [&](const ObjCObjectType *Ty) {
if (!Ty)
return;
if (const auto *clsD = Ty->getInterface()) {
Relations.emplace_back((unsigned)SymbolRole::RelationReceivedBy,
clsD);
}
for (const auto *protD : Ty->quals()) {
Relations.emplace_back((unsigned)SymbolRole::RelationReceivedBy,
protD);
}
};
QualType recT = E->getReceiverType();
if (const auto *Ptr = recT->getAs<ObjCObjectPointerType>())
addReceivers(Ptr->getObjectType());
else
addReceivers(recT->getAs<ObjCObjectType>());
}
return IndexCtx.handleReference(MD, E->getSelectorStartLoc(),
Parent, ParentDC, Roles, Relations, E);
}
return true;
}
bool VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
if (E->isExplicitProperty()) {
SmallVector<SymbolRelation, 2> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(E->getExplicitProperty(), E->getLocation(),
Parent, ParentDC, Roles, Relations, E);
} else if (const ObjCMethodDecl *Getter = E->getImplicitPropertyGetter()) {
// Class properties that are explicitly defined using @property
// declarations are represented implicitly as there is no ivar for class
// properties.
if (Getter->isClassMethod()) {
if (const auto *PD = Getter->getCanonicalDecl()->findPropertyDecl()) {
SmallVector<SymbolRelation, 2> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
return IndexCtx.handleReference(PD, E->getLocation(), Parent,
ParentDC, Roles, Relations, E);
}
}
}
// No need to do a handleReference for the objc method, because there will
// be a message expr as part of PseudoObjectExpr.
return true;
}
bool VisitMSPropertyRefExpr(MSPropertyRefExpr *E) {
return IndexCtx.handleReference(E->getPropertyDecl(), E->getMemberLoc(),
Parent, ParentDC, SymbolRoleSet(), {}, E);
}
bool VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
return IndexCtx.handleReference(E->getProtocol(), E->getProtocolIdLoc(),
Parent, ParentDC, SymbolRoleSet(), {}, E);
}
bool passObjCLiteralMethodCall(const ObjCMethodDecl *MD, const Expr *E) {
SymbolRoleSet Roles{};
SmallVector<SymbolRelation, 2> Relations;
addCallRole(Roles, Relations);
Roles |= (unsigned)SymbolRole::Implicit;
return IndexCtx.handleReference(MD, E->getBeginLoc(), Parent, ParentDC,
Roles, Relations, E);
}
bool VisitObjCBoxedExpr(ObjCBoxedExpr *E) {
if (ObjCMethodDecl *MD = E->getBoxingMethod()) {
return passObjCLiteralMethodCall(MD, E);
}
return true;
}
bool VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
if (ObjCMethodDecl *MD = E->getDictWithObjectsMethod()) {
return passObjCLiteralMethodCall(MD, E);
}
return true;
}
bool VisitObjCArrayLiteral(ObjCArrayLiteral *E) {
if (ObjCMethodDecl *MD = E->getArrayWithObjectsMethod()) {
return passObjCLiteralMethodCall(MD, E);
}
return true;
}
bool VisitCXXConstructExpr(CXXConstructExpr *E) {
SymbolRoleSet Roles{};
SmallVector<SymbolRelation, 2> Relations;
addCallRole(Roles, Relations);
return IndexCtx.handleReference(E->getConstructor(), E->getLocation(),
Parent, ParentDC, Roles, Relations, E);
}
bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *E,
DataRecursionQueue *Q = nullptr) {
if (E->getOperatorLoc().isInvalid())
return true; // implicit.
return base::TraverseCXXOperatorCallExpr(E, Q);
}
bool VisitDeclStmt(DeclStmt *S) {
if (IndexCtx.shouldIndexFunctionLocalSymbols()) {
IndexCtx.indexDeclGroupRef(S->getDeclGroup());
return true;
}
DeclGroupRef DG = S->getDeclGroup();
for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) {
const Decl *D = *I;
if (!D)
continue;
if (!isFunctionLocalSymbol(D))
IndexCtx.indexTopLevelDecl(D);
}
return true;
}
bool TraverseLambdaCapture(LambdaExpr *LE, const LambdaCapture *C,
Expr *Init) {
if (C->capturesThis() || C->capturesVLAType())
return true;
if (!base::TraverseStmt(Init))
return false;
if (C->capturesVariable() && IndexCtx.shouldIndexFunctionLocalSymbols())
return IndexCtx.handleReference(C->getCapturedVar(), C->getLocation(),
Parent, ParentDC, SymbolRoleSet());
return true;
}
// RecursiveASTVisitor visits both syntactic and semantic forms, duplicating
// the things that we visit. Make sure to only visit the semantic form.
// Also visit things that are in the syntactic form but not the semantic one,
// for example the indices in DesignatedInitExprs.
bool TraverseInitListExpr(InitListExpr *S, DataRecursionQueue *Q = nullptr) {
auto visitForm = [&](InitListExpr *Form) {
for (Stmt *SubStmt : Form->children()) {
if (!TraverseStmt(SubStmt, Q))
return false;
}
return true;
};
auto visitSyntacticDesignatedInitExpr = [&](DesignatedInitExpr *E) -> bool {
for (DesignatedInitExpr::Designator &D : llvm::reverse(E->designators())) {
if (D.isFieldDesignator() && D.getField())
return IndexCtx.handleReference(D.getField(), D.getFieldLoc(),
Parent, ParentDC, SymbolRoleSet(),
{}, E);
}
return true;
};
InitListExpr *SemaForm = S->isSemanticForm() ? S : S->getSemanticForm();
InitListExpr *SyntaxForm = S->isSemanticForm() ? S->getSyntacticForm() : S;
if (SemaForm) {
// Visit things present in syntactic form but not the semantic form.
if (SyntaxForm) {
for (Expr *init : SyntaxForm->inits()) {
if (auto *DIE = dyn_cast<DesignatedInitExpr>(init))
visitSyntacticDesignatedInitExpr(DIE);
}
}
return visitForm(SemaForm);
}
// No semantic, try the syntactic.
if (SyntaxForm) {
return visitForm(SyntaxForm);
}
return true;
}
bool VisitOffsetOfExpr(OffsetOfExpr *S) {
for (unsigned I = 0, E = S->getNumComponents(); I != E; ++I) {
const OffsetOfNode &Component = S->getComponent(I);
if (Component.getKind() == OffsetOfNode::Field)
IndexCtx.handleReference(Component.getField(), Component.getEndLoc(),
Parent, ParentDC, SymbolRoleSet(), {});
// FIXME: Try to resolve dependent field references.
}
return true;
}
bool VisitParmVarDecl(ParmVarDecl* D) {
// Index the parameters of lambda expression and requires expression.
if (IndexCtx.shouldIndexFunctionLocalSymbols()) {
const auto *DC = D->getDeclContext();
if (DC && (isLambdaCallOperator(DC) || isa<RequiresExprBodyDecl>(DC)))
IndexCtx.handleDecl(D);
}
return true;
}
bool VisitUnresolvedLookupExpr(UnresolvedLookupExpr *E) {
SmallVector<SymbolRelation, 4> Relations;
SymbolRoleSet Roles = getRolesForRef(E, Relations);
for (auto *D : E->decls())
IndexCtx.handleReference(D, E->getNameLoc(), Parent, ParentDC, Roles,
Relations, E);
return true;
}
bool VisitConceptSpecializationExpr(ConceptSpecializationExpr *R) {
IndexCtx.handleReference(R->getNamedConcept(), R->getConceptNameLoc(),
Parent, ParentDC);
return true;
}
bool VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
// This handles references in return type requirements of RequiresExpr.
// E.g. `requires (T x) { {*x} -> ConceptRef }`
if (auto *C = D->getTypeConstraint())
IndexCtx.handleReference(C->getNamedConcept(), C->getConceptNameLoc(),
Parent, ParentDC);
return true;
}
};
} // anonymous namespace
void IndexingContext::indexBody(const Stmt *S, const NamedDecl *Parent,
const DeclContext *DC) {
if (!S)
return;
if (!DC)
DC = Parent->getLexicalDeclContext();
BodyIndexer(*this, Parent, DC).TraverseStmt(const_cast<Stmt*>(S));
}