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