clang-tools-extra/clangd/DumpAST.cpp

   1 //===--- DumpAST.cpp - Serialize clang AST to LSP -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "DumpAST.h"
  10 #include "Protocol.h"
  11 #include "SourceCode.h"
  12 #include "support/Logger.h"
  13 #include "clang/AST/ASTTypeTraits.h"
  14 #include "clang/AST/Expr.h"
  15 #include "clang/AST/ExprCXX.h"
  16 #include "clang/AST/NestedNameSpecifier.h"
  17 #include "clang/AST/PrettyPrinter.h"
  18 #include "clang/AST/RecursiveASTVisitor.h"
  19 #include "clang/AST/TextNodeDumper.h"
  20 #include "clang/AST/Type.h"
  21 #include "clang/AST/TypeLoc.h"
  22 #include "clang/Basic/Specifiers.h"
  23 #include "clang/Tooling/Syntax/Tokens.h"
  24 #include "llvm/ADT/StringRef.h"
  25 #include "llvm/Support/raw_ostream.h"
  26 #include <optional>
  27
  28 namespace clang {
  29 namespace clangd {
  30 namespace {
  31
  32 using llvm::raw_ostream;
  33 template <typename Print> std::string toString(const Print &C) {
  34   std::string Result;
  35   llvm::raw_string_ostream OS(Result);
  36   C(OS);
  37   return std::move(OS.str());
  38 }
  39
  40 bool isInjectedClassName(Decl *D) {
  41   if (const auto *CRD = llvm::dyn_cast<CXXRecordDecl>(D))
  42     return CRD->isInjectedClassName();
  43   return false;
  44 }
  45
  46 class DumpVisitor : public RecursiveASTVisitor<DumpVisitor> {
  47   using Base = RecursiveASTVisitor<DumpVisitor>;
  48
  49   const syntax::TokenBuffer &Tokens;
  50   const ASTContext &Ctx;
  51
  52   // Pointers are into 'children' vector.
  53   // They remain valid because while a node is on the stack we only add
  54   // descendants, not siblings.
  55   std::vector<ASTNode *> Stack;
  56
  57   // Generic logic used to handle traversal of all node kinds.
  58
  59   template <typename T>
  60   bool traverseNodePre(llvm::StringRef Role, const T &Node) {
  61     if (Stack.empty()) {
  62       assert(Root.role.empty());
  63       Stack.push_back(&Root);
  64     } else {
  65       Stack.back()->children.emplace_back();
  66       Stack.push_back(&Stack.back()->children.back());
  67     }
  68     auto &N = *Stack.back();
  69     N.role = Role.str();
  70     N.kind = getKind(Node);
  71     N.detail = getDetail(Node);
  72     N.range = getRange(Node);
  73     N.arcana = getArcana(Node);
  74     return true;
  75   }
  76   bool traverseNodePost() {
  77     assert(!Stack.empty());
  78     Stack.pop_back();
  79     return true;
  80   }
  81   template <typename T, typename Callable>
  82   bool traverseNode(llvm::StringRef Role, const T &Node, const Callable &Body) {
  83     traverseNodePre(Role, Node);
  84     Body();
  85     return traverseNodePost();
  86   }
  87
  88   // Range: most nodes have getSourceRange(), with a couple of exceptions.
  89   // We only return it if it's valid at both ends and there are no macros.
  90
  91   template <typename T> std::optional<Range> getRange(const T &Node) {
  92     SourceRange SR = getSourceRange(Node);
  93     auto Spelled = Tokens.spelledForExpanded(Tokens.expandedTokens(SR));
  94     if (!Spelled)
  95       return std::nullopt;
  96     return halfOpenToRange(
  97         Tokens.sourceManager(),
  98         CharSourceRange::getCharRange(Spelled->front().location(),
  99                                       Spelled->back().endLocation()));
 100   }
 101   template <typename T, typename = decltype(std::declval<T>().getSourceRange())>
 102   SourceRange getSourceRange(const T &Node) {
 103     return Node.getSourceRange();
 104   }
 105   template <typename T,
 106             typename = decltype(std::declval<T *>()->getSourceRange())>
 107   SourceRange getSourceRange(const T *Node) {
 108     return Node->getSourceRange();
 109   }
 110   // TemplateName doesn't have a real Loc node type.
 111   SourceRange getSourceRange(const TemplateName &Node) { return SourceRange(); }
 112   // Attr just uses a weird method name. Maybe we should fix it instead?
 113   SourceRange getSourceRange(const Attr *Node) { return Node->getRange(); }
 114
 115   // Kind is usually the class name, without the suffix ("Type" etc).
 116   // Where there's a set of variants instead, we use the 'Kind' enum values.
 117
 118   std::string getKind(const Decl *D) { return D->getDeclKindName(); }
 119   std::string getKind(const Stmt *S) {
 120     std::string Result = S->getStmtClassName();
 121     if (llvm::StringRef(Result).endswith("Stmt") ||
 122         llvm::StringRef(Result).endswith("Expr"))
 123       Result.resize(Result.size() - 4);
 124     return Result;
 125   }
 126   std::string getKind(const TypeLoc &TL) {
 127     std::string Result;
 128     if (TL.getTypeLocClass() == TypeLoc::Qualified)
 129       return "Qualified";
 130     return TL.getType()->getTypeClassName();
 131   }
 132   std::string getKind(const TemplateArgumentLoc &TAL) {
 133     switch (TAL.getArgument().getKind()) {
 134 #define TEMPLATE_ARGUMENT_KIND(X)                                              \
 135   case TemplateArgument::X:                                                    \
 136     return #X
 137       TEMPLATE_ARGUMENT_KIND(Null);
 138       TEMPLATE_ARGUMENT_KIND(NullPtr);
 139       TEMPLATE_ARGUMENT_KIND(Expression);
 140       TEMPLATE_ARGUMENT_KIND(Integral);
 141       TEMPLATE_ARGUMENT_KIND(Pack);
 142       TEMPLATE_ARGUMENT_KIND(Type);
 143       TEMPLATE_ARGUMENT_KIND(Declaration);
 144       TEMPLATE_ARGUMENT_KIND(Template);
 145       TEMPLATE_ARGUMENT_KIND(TemplateExpansion);
 146 #undef TEMPLATE_ARGUMENT_KIND
 147     }
 148     llvm_unreachable("Unhandled ArgKind enum");
 149   }
 150   std::string getKind(const NestedNameSpecifierLoc &NNSL) {
 151     assert(NNSL.getNestedNameSpecifier());
 152     switch (NNSL.getNestedNameSpecifier()->getKind()) {
 153 #define NNS_KIND(X)                                                            \
 154   case NestedNameSpecifier::X:                                                 \
 155     return #X
 156       NNS_KIND(Identifier);
 157       NNS_KIND(Namespace);
 158       NNS_KIND(TypeSpec);
 159       NNS_KIND(TypeSpecWithTemplate);
 160       NNS_KIND(Global);
 161       NNS_KIND(Super);
 162       NNS_KIND(NamespaceAlias);
 163 #undef NNS_KIND
 164     }
 165     llvm_unreachable("Unhandled SpecifierKind enum");
 166   }
 167   std::string getKind(const CXXCtorInitializer *CCI) {
 168     if (CCI->isBaseInitializer())
 169       return "BaseInitializer";
 170     if (CCI->isDelegatingInitializer())
 171       return "DelegatingInitializer";
 172     if (CCI->isAnyMemberInitializer())
 173       return "MemberInitializer";
 174     llvm_unreachable("Unhandled CXXCtorInitializer type");
 175   }
 176   std::string getKind(const TemplateName &TN) {
 177     switch (TN.getKind()) {
 178 #define TEMPLATE_KIND(X)                                                       \
 179   case TemplateName::X:                                                        \
 180     return #X;
 181       TEMPLATE_KIND(Template);
 182       TEMPLATE_KIND(OverloadedTemplate);
 183       TEMPLATE_KIND(AssumedTemplate);
 184       TEMPLATE_KIND(QualifiedTemplate);
 185       TEMPLATE_KIND(DependentTemplate);
 186       TEMPLATE_KIND(SubstTemplateTemplateParm);
 187       TEMPLATE_KIND(SubstTemplateTemplateParmPack);
 188       TEMPLATE_KIND(UsingTemplate);
 189 #undef TEMPLATE_KIND
 190     }
 191     llvm_unreachable("Unhandled NameKind enum");
 192   }
 193   std::string getKind(const Attr *A) {
 194     switch (A->getKind()) {
 195 #define ATTR(X)                                                                \
 196   case attr::X:                                                                \
 197     return #X;
 198 #include "clang/Basic/AttrList.inc"
 199 #undef ATTR
 200     }
 201     llvm_unreachable("Unhandled attr::Kind enum");
 202   }
 203   std::string getKind(const CXXBaseSpecifier &CBS) {
 204     // There aren't really any variants of CXXBaseSpecifier.
 205     // To avoid special cases in the API/UI, use public/private as the kind.
 206     return getAccessSpelling(CBS.getAccessSpecifier()).str();
 207   }
 208   std::string getKind(const ConceptReference *CR) {
 209     // Again there are no variants here.
 210     // Kind is "Concept", role is "reference"
 211     return "Concept";
 212   }
 213
 214   // Detail is the single most important fact about the node.
 215   // Often this is the name, sometimes a "kind" enum like operators or casts.
 216   // We should avoid unbounded text, like dumping parameter lists.
 217
 218   std::string getDetail(const Decl *D) {
 219     const auto *ND = dyn_cast<NamedDecl>(D);
 220     if (!ND || llvm::isa_and_nonnull<CXXConstructorDecl>(ND->getAsFunction()) ||
 221         isa<CXXDestructorDecl>(ND))
 222       return "";
 223     std::string Name = toString([&](raw_ostream &OS) { ND->printName(OS); });
 224     if (Name.empty())
 225       return "(anonymous)";
 226     return Name;
 227   }
 228   std::string getDetail(const Stmt *S) {
 229     if (const auto *DRE = dyn_cast<DeclRefExpr>(S))
 230       return DRE->getNameInfo().getAsString();
 231     if (const auto *DSDRE = dyn_cast<DependentScopeDeclRefExpr>(S))
 232       return DSDRE->getNameInfo().getAsString();
 233     if (const auto *ME = dyn_cast<MemberExpr>(S))
 234       return ME->getMemberNameInfo().getAsString();
 235     if (const auto *CE = dyn_cast<CastExpr>(S))
 236       return CE->getCastKindName();
 237     if (const auto *BO = dyn_cast<BinaryOperator>(S))
 238       return BO->getOpcodeStr().str();
 239     if (const auto *UO = dyn_cast<UnaryOperator>(S))
 240       return UnaryOperator::getOpcodeStr(UO->getOpcode()).str();
 241     if (const auto *CCO = dyn_cast<CXXConstructExpr>(S))
 242       return CCO->getConstructor()->getNameAsString();
 243     if (const auto *CTE = dyn_cast<CXXThisExpr>(S)) {
 244       bool Const = CTE->getType()->getPointeeType().isLocalConstQualified();
 245       if (CTE->isImplicit())
 246         return Const ? "const, implicit" : "implicit";
 247       if (Const)
 248         return "const";
 249       return "";
 250     }
 251     if (isa<IntegerLiteral, FloatingLiteral, FixedPointLiteral,
 252             CharacterLiteral, ImaginaryLiteral, CXXBoolLiteralExpr>(S))
 253       return toString([&](raw_ostream &OS) {
 254         S->printPretty(OS, nullptr, Ctx.getPrintingPolicy());
 255       });
 256     if (const auto *MTE = dyn_cast<MaterializeTemporaryExpr>(S))
 257       return MTE->isBoundToLvalueReference() ? "lvalue" : "rvalue";
 258     return "";
 259   }
 260   std::string getDetail(const TypeLoc &TL) {
 261     if (TL.getType().hasLocalQualifiers())
 262       return TL.getType().getLocalQualifiers().getAsString(
 263           Ctx.getPrintingPolicy());
 264     if (const auto *TT = dyn_cast<TagType>(TL.getTypePtr()))
 265       return getDetail(TT->getDecl());
 266     if (const auto *DT = dyn_cast<DeducedType>(TL.getTypePtr()))
 267       if (DT->isDeduced())
 268         return DT->getDeducedType().getAsString(Ctx.getPrintingPolicy());
 269     if (const auto *BT = dyn_cast<BuiltinType>(TL.getTypePtr()))
 270       return BT->getName(Ctx.getPrintingPolicy()).str();
 271     if (const auto *TTPT = dyn_cast<TemplateTypeParmType>(TL.getTypePtr()))
 272       return getDetail(TTPT->getDecl());
 273     if (const auto *TT = dyn_cast<TypedefType>(TL.getTypePtr()))
 274       return getDetail(TT->getDecl());
 275     return "";
 276   }
 277   std::string getDetail(const NestedNameSpecifierLoc &NNSL) {
 278     const auto &NNS = *NNSL.getNestedNameSpecifier();
 279     switch (NNS.getKind()) {
 280     case NestedNameSpecifier::Identifier:
 281       return NNS.getAsIdentifier()->getName().str() + "::";
 282     case NestedNameSpecifier::Namespace:
 283       return NNS.getAsNamespace()->getNameAsString() + "::";
 284     case NestedNameSpecifier::NamespaceAlias:
 285       return NNS.getAsNamespaceAlias()->getNameAsString() + "::";
 286     default:
 287       return "";
 288     }
 289   }
 290   std::string getDetail(const CXXCtorInitializer *CCI) {
 291     if (FieldDecl *FD = CCI->getAnyMember())
 292       return getDetail(FD);
 293     if (TypeLoc TL = CCI->getBaseClassLoc())
 294       return getDetail(TL);
 295     return "";
 296   }
 297   std::string getDetail(const TemplateArgumentLoc &TAL) {
 298     if (TAL.getArgument().getKind() == TemplateArgument::Integral)
 299       return toString(TAL.getArgument().getAsIntegral(), 10);
 300     return "";
 301   }
 302   std::string getDetail(const TemplateName &TN) {
 303     return toString([&](raw_ostream &OS) {
 304       TN.print(OS, Ctx.getPrintingPolicy(), TemplateName::Qualified::None);
 305     });
 306   }
 307   std::string getDetail(const Attr *A) {
 308     return A->getAttrName() ? A->getNormalizedFullName() : A->getSpelling();
 309   }
 310   std::string getDetail(const CXXBaseSpecifier &CBS) {
 311     return CBS.isVirtual() ? "virtual" : "";
 312   }
 313   std::string getDetail(const ConceptReference *CR) {
 314     return CR->getNamedConcept()->getNameAsString();
 315   }
 316
 317   /// Arcana is produced by TextNodeDumper, for the types it supports.
 318
 319   template <typename Dump> std::string dump(const Dump &D) {
 320     return toString([&](raw_ostream &OS) {
 321       TextNodeDumper Dumper(OS, Ctx, /*ShowColors=*/false);
 322       D(Dumper);
 323     });
 324   }
 325   template <typename T> std::string getArcana(const T &N) {
 326     return dump([&](TextNodeDumper &D) { D.Visit(N); });
 327   }
 328   std::string getArcana(const NestedNameSpecifierLoc &NNS) { return ""; }
 329   std::string getArcana(const TemplateName &NNS) { return ""; }
 330   std::string getArcana(const CXXBaseSpecifier &CBS) { return ""; }
 331   std::string getArcana(const TemplateArgumentLoc &TAL) {
 332     return dump([&](TextNodeDumper &D) {
 333       D.Visit(TAL.getArgument(), TAL.getSourceRange());
 334     });
 335   }
 336   std::string getArcana(const TypeLoc &TL) {
 337     return dump([&](TextNodeDumper &D) { D.Visit(TL.getType()); });
 338   }
 339
 340 public:
 341   ASTNode Root;
 342   DumpVisitor(const syntax::TokenBuffer &Tokens, const ASTContext &Ctx)
 343       : Tokens(Tokens), Ctx(Ctx) {}
 344
 345   // Override traversal to record the nodes we care about.
 346   // Generally, these are nodes with position information (TypeLoc, not Type).
 347
 348   bool TraverseDecl(Decl *D) {
 349     return !D || isInjectedClassName(D) ||
 350            traverseNode("declaration", D, [&] { Base::TraverseDecl(D); });
 351   }
 352   bool TraverseTypeLoc(TypeLoc TL) {
 353     return !TL || traverseNode("type", TL, [&] { Base::TraverseTypeLoc(TL); });
 354   }
 355   bool TraverseTemplateName(const TemplateName &TN) {
 356     return traverseNode("template name", TN,
 357                         [&] { Base::TraverseTemplateName(TN); });
 358   }
 359   bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &TAL) {
 360     return traverseNode("template argument", TAL,
 361                         [&] { Base::TraverseTemplateArgumentLoc(TAL); });
 362   }
 363   bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNSL) {
 364     return !NNSL || traverseNode("specifier", NNSL, [&] {
 365       Base::TraverseNestedNameSpecifierLoc(NNSL);
 366     });
 367   }
 368   bool TraverseConstructorInitializer(CXXCtorInitializer *CCI) {
 369     return !CCI || traverseNode("constructor initializer", CCI, [&] {
 370       Base::TraverseConstructorInitializer(CCI);
 371     });
 372   }
 373   bool TraverseAttr(Attr *A) {
 374     return !A || traverseNode("attribute", A, [&] { Base::TraverseAttr(A); });
 375   }
 376   bool TraverseConceptReference(ConceptReference *C) {
 377     return !C || traverseNode("reference", C,
 378                               [&] { Base::TraverseConceptReference(C); });
 379   }
 380   bool TraverseCXXBaseSpecifier(const CXXBaseSpecifier &CBS) {
 381     return traverseNode("base", CBS,
 382                         [&] { Base::TraverseCXXBaseSpecifier(CBS); });
 383   }
 384   // Stmt is the same, but this form allows the data recursion optimization.
 385   bool dataTraverseStmtPre(Stmt *S) {
 386     return S && traverseNodePre(isa<Expr>(S) ? "expression" : "statement", S);
 387   }
 388   bool dataTraverseStmtPost(Stmt *X) { return traverseNodePost(); }
 389
 390   // QualifiedTypeLoc is handled strangely in RecursiveASTVisitor: the derived
 391   // TraverseTypeLoc is not called for the inner UnqualTypeLoc.
 392   // This means we'd never see 'int' in 'const int'! Work around that here.
 393   // (The reason for the behavior is to avoid traversing the nested Type twice,
 394   // but we ignore TraverseType anyway).
 395   bool TraverseQualifiedTypeLoc(QualifiedTypeLoc QTL) {
 396     return TraverseTypeLoc(QTL.getUnqualifiedLoc());
 397   }
 398   // Uninteresting parts of the AST that don't have locations within them.
 399   bool TraverseNestedNameSpecifier(NestedNameSpecifier *) { return true; }
 400   bool TraverseType(QualType) { return true; }
 401
 402   // OpaqueValueExpr blocks traversal, we must explicitly traverse it.
 403   bool TraverseOpaqueValueExpr(OpaqueValueExpr *E) {
 404     return TraverseStmt(E->getSourceExpr());
 405   }
 406   // We only want to traverse the *syntactic form* to understand the selection.
 407   bool TraversePseudoObjectExpr(PseudoObjectExpr *E) {
 408     return TraverseStmt(E->getSyntacticForm());
 409   }
 410 };
 411
 412 } // namespace
 413
 414 ASTNode dumpAST(const DynTypedNode &N, const syntax::TokenBuffer &Tokens,
 415                 const ASTContext &Ctx) {
 416   DumpVisitor V(Tokens, Ctx);
 417   // DynTypedNode only works with const, RecursiveASTVisitor only non-const :-(
 418   if (const auto *D = N.get<Decl>())
 419     V.TraverseDecl(const_cast<Decl *>(D));
 420   else if (const auto *S = N.get<Stmt>())
 421     V.TraverseStmt(const_cast<Stmt *>(S));
 422   else if (const auto *NNSL = N.get<NestedNameSpecifierLoc>())
 423     V.TraverseNestedNameSpecifierLoc(
 424         *const_cast<NestedNameSpecifierLoc *>(NNSL));
 425   else if (const auto *NNS = N.get<NestedNameSpecifier>())
 426     V.TraverseNestedNameSpecifier(const_cast<NestedNameSpecifier *>(NNS));
 427   else if (const auto *TL = N.get<TypeLoc>())
 428     V.TraverseTypeLoc(*const_cast<TypeLoc *>(TL));
 429   else if (const auto *QT = N.get<QualType>())
 430     V.TraverseType(*const_cast<QualType *>(QT));
 431   else if (const auto *CCI = N.get<CXXCtorInitializer>())
 432     V.TraverseConstructorInitializer(const_cast<CXXCtorInitializer *>(CCI));
 433   else if (const auto *TAL = N.get<TemplateArgumentLoc>())
 434     V.TraverseTemplateArgumentLoc(*const_cast<TemplateArgumentLoc *>(TAL));
 435   else if (const auto *CBS = N.get<CXXBaseSpecifier>())
 436     V.TraverseCXXBaseSpecifier(*const_cast<CXXBaseSpecifier *>(CBS));
 437   else if (const auto *CR = N.get<ConceptReference>())
 438     V.TraverseConceptReference(const_cast<ConceptReference *>(CR));
 439   else
 440     elog("dumpAST: unhandled DynTypedNode kind {0}",
 441          N.getNodeKind().asStringRef());
 442   return std::move(V.Root);
 443 }
 444
 445 } // namespace clangd
 446 } // namespace clang