clang/lib/AST/Comment.cpp

   1 //===--- Comment.cpp - Comment AST node implementation --------------------===//
   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 "clang/AST/Comment.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/AST/Decl.h"
  12 #include "clang/AST/DeclObjC.h"
  13 #include "clang/AST/DeclTemplate.h"
  14 #include "clang/Basic/CharInfo.h"
  15 #include "llvm/Support/ErrorHandling.h"
  16 #include <type_traits>
  17
  18 namespace clang {
  19 namespace comments {
  20
  21 // Check that no comment class has a non-trival destructor. They are allocated
  22 // with a BumpPtrAllocator and therefore their destructor is not executed.
  23 #define ABSTRACT_COMMENT(COMMENT)
  24 #define COMMENT(CLASS, PARENT)                                                 \
  25   static_assert(std::is_trivially_destructible<CLASS>::value,                  \
  26                 #CLASS " should be trivially destructible!");
  27 #include "clang/AST/CommentNodes.inc"
  28 #undef COMMENT
  29 #undef ABSTRACT_COMMENT
  30
  31 // DeclInfo is also allocated with a BumpPtrAllocator.
  32 static_assert(std::is_trivially_destructible_v<DeclInfo>,
  33               "DeclInfo should be trivially destructible!");
  34
  35 const char *Comment::getCommentKindName() const {
  36   switch (getCommentKind()) {
  37   case CommentKind::None:
  38     return "None";
  39 #define ABSTRACT_COMMENT(COMMENT)
  40 #define COMMENT(CLASS, PARENT)                                                 \
  41   case CommentKind::CLASS:                                                     \
  42     return #CLASS;
  43 #include "clang/AST/CommentNodes.inc"
  44 #undef COMMENT
  45 #undef ABSTRACT_COMMENT
  46   }
  47   llvm_unreachable("Unknown comment kind!");
  48 }
  49
  50 namespace {
  51 struct good {};
  52 struct bad {};
  53
  54 template <typename T>
  55 good implements_child_begin_end(Comment::child_iterator (T::*)() const) {
  56   return good();
  57 }
  58
  59 LLVM_ATTRIBUTE_UNUSED
  60 static inline bad implements_child_begin_end(
  61                       Comment::child_iterator (Comment::*)() const) {
  62   return bad();
  63 }
  64
  65 #define ASSERT_IMPLEMENTS_child_begin(function) \
  66   (void) good(implements_child_begin_end(function))
  67
  68 LLVM_ATTRIBUTE_UNUSED
  69 static inline void CheckCommentASTNodes() {
  70 #define ABSTRACT_COMMENT(COMMENT)
  71 #define COMMENT(CLASS, PARENT) \
  72   ASSERT_IMPLEMENTS_child_begin(&CLASS::child_begin); \
  73   ASSERT_IMPLEMENTS_child_begin(&CLASS::child_end);
  74 #include "clang/AST/CommentNodes.inc"
  75 #undef COMMENT
  76 #undef ABSTRACT_COMMENT
  77 }
  78
  79 #undef ASSERT_IMPLEMENTS_child_begin
  80
  81 } // end unnamed namespace
  82
  83 Comment::child_iterator Comment::child_begin() const {
  84   switch (getCommentKind()) {
  85   case CommentKind::None:
  86     llvm_unreachable("comment without a kind");
  87 #define ABSTRACT_COMMENT(COMMENT)
  88 #define COMMENT(CLASS, PARENT)                                                 \
  89   case CommentKind::CLASS:                                                     \
  90     return static_cast<const CLASS *>(this)->child_begin();
  91 #include "clang/AST/CommentNodes.inc"
  92 #undef COMMENT
  93 #undef ABSTRACT_COMMENT
  94   }
  95   llvm_unreachable("Unknown comment kind!");
  96 }
  97
  98 Comment::child_iterator Comment::child_end() const {
  99   switch (getCommentKind()) {
 100   case CommentKind::None:
 101     llvm_unreachable("comment without a kind");
 102 #define ABSTRACT_COMMENT(COMMENT)
 103 #define COMMENT(CLASS, PARENT)                                                 \
 104   case CommentKind::CLASS:                                                     \
 105     return static_cast<const CLASS *>(this)->child_end();
 106 #include "clang/AST/CommentNodes.inc"
 107 #undef COMMENT
 108 #undef ABSTRACT_COMMENT
 109   }
 110   llvm_unreachable("Unknown comment kind!");
 111 }
 112
 113 bool TextComment::isWhitespaceNoCache() const {
 114   return llvm::all_of(Text, clang::isWhitespace);
 115 }
 116
 117 bool ParagraphComment::isWhitespaceNoCache() const {
 118   for (child_iterator I = child_begin(), E = child_end(); I != E; ++I) {
 119     if (const TextComment *TC = dyn_cast<TextComment>(*I)) {
 120       if (!TC->isWhitespace())
 121         return false;
 122     } else
 123       return false;
 124   }
 125   return true;
 126 }
 127
 128 static TypeLoc lookThroughTypedefOrTypeAliasLocs(TypeLoc &SrcTL) {
 129   TypeLoc TL = SrcTL.IgnoreParens();
 130
 131   // Look through attribute types.
 132   if (AttributedTypeLoc AttributeTL = TL.getAs<AttributedTypeLoc>())
 133     return AttributeTL.getModifiedLoc();
 134   // Look through qualified types.
 135   if (QualifiedTypeLoc QualifiedTL = TL.getAs<QualifiedTypeLoc>())
 136     return QualifiedTL.getUnqualifiedLoc();
 137   // Look through pointer types.
 138   if (PointerTypeLoc PointerTL = TL.getAs<PointerTypeLoc>())
 139     return PointerTL.getPointeeLoc().getUnqualifiedLoc();
 140   // Look through reference types.
 141   if (ReferenceTypeLoc ReferenceTL = TL.getAs<ReferenceTypeLoc>())
 142     return ReferenceTL.getPointeeLoc().getUnqualifiedLoc();
 143   // Look through adjusted types.
 144   if (AdjustedTypeLoc ATL = TL.getAs<AdjustedTypeLoc>())
 145     return ATL.getOriginalLoc();
 146   if (BlockPointerTypeLoc BlockPointerTL = TL.getAs<BlockPointerTypeLoc>())
 147     return BlockPointerTL.getPointeeLoc().getUnqualifiedLoc();
 148   if (MemberPointerTypeLoc MemberPointerTL = TL.getAs<MemberPointerTypeLoc>())
 149     return MemberPointerTL.getPointeeLoc().getUnqualifiedLoc();
 150   if (ElaboratedTypeLoc ETL = TL.getAs<ElaboratedTypeLoc>())
 151     return ETL.getNamedTypeLoc();
 152
 153   return TL;
 154 }
 155
 156 static bool getFunctionTypeLoc(TypeLoc TL, FunctionTypeLoc &ResFTL) {
 157   TypeLoc PrevTL;
 158   while (PrevTL != TL) {
 159     PrevTL = TL;
 160     TL = lookThroughTypedefOrTypeAliasLocs(TL);
 161   }
 162
 163   if (FunctionTypeLoc FTL = TL.getAs<FunctionTypeLoc>()) {
 164     ResFTL = FTL;
 165     return true;
 166   }
 167
 168   if (TemplateSpecializationTypeLoc STL =
 169           TL.getAs<TemplateSpecializationTypeLoc>()) {
 170     // If we have a typedef to a template specialization with exactly one
 171     // template argument of a function type, this looks like std::function,
 172     // boost::function, or other function wrapper.  Treat these typedefs as
 173     // functions.
 174     if (STL.getNumArgs() != 1)
 175       return false;
 176     TemplateArgumentLoc MaybeFunction = STL.getArgLoc(0);
 177     if (MaybeFunction.getArgument().getKind() != TemplateArgument::Type)
 178       return false;
 179     TypeSourceInfo *MaybeFunctionTSI = MaybeFunction.getTypeSourceInfo();
 180     TypeLoc TL = MaybeFunctionTSI->getTypeLoc().getUnqualifiedLoc();
 181     if (FunctionTypeLoc FTL = TL.getAs<FunctionTypeLoc>()) {
 182       ResFTL = FTL;
 183       return true;
 184     }
 185   }
 186
 187   return false;
 188 }
 189
 190 const char *
 191 ParamCommandComment::getDirectionAsString(ParamCommandPassDirection D) {
 192   switch (D) {
 193   case ParamCommandPassDirection::In:
 194     return "[in]";
 195   case ParamCommandPassDirection::Out:
 196     return "[out]";
 197   case ParamCommandPassDirection::InOut:
 198     return "[in,out]";
 199   }
 200   llvm_unreachable("unknown PassDirection");
 201 }
 202
 203 void DeclInfo::fill() {
 204   assert(!IsFilled);
 205
 206   // Set defaults.
 207   Kind = OtherKind;
 208   TemplateKind = NotTemplate;
 209   IsObjCMethod = false;
 210   IsInstanceMethod = false;
 211   IsClassMethod = false;
 212   IsVariadic = false;
 213   ParamVars = {};
 214   TemplateParameters = nullptr;
 215
 216   if (!CommentDecl) {
 217     // If there is no declaration, the defaults is our only guess.
 218     IsFilled = true;
 219     return;
 220   }
 221   CurrentDecl = CommentDecl;
 222
 223   Decl::Kind K = CommentDecl->getKind();
 224   const TypeSourceInfo *TSI = nullptr;
 225   switch (K) {
 226   default:
 227     // Defaults are should be good for declarations we don't handle explicitly.
 228     break;
 229   case Decl::Function:
 230   case Decl::CXXMethod:
 231   case Decl::CXXConstructor:
 232   case Decl::CXXDestructor:
 233   case Decl::CXXConversion: {
 234     const FunctionDecl *FD = cast<FunctionDecl>(CommentDecl);
 235     Kind = FunctionKind;
 236     ParamVars = FD->parameters();
 237     ReturnType = FD->getReturnType();
 238     unsigned NumLists = FD->getNumTemplateParameterLists();
 239     if (NumLists != 0) {
 240       TemplateKind = TemplateSpecialization;
 241       TemplateParameters =
 242           FD->getTemplateParameterList(NumLists - 1);
 243     }
 244
 245     if (K == Decl::CXXMethod || K == Decl::CXXConstructor ||
 246         K == Decl::CXXDestructor || K == Decl::CXXConversion) {
 247       const CXXMethodDecl *MD = cast<CXXMethodDecl>(CommentDecl);
 248       IsInstanceMethod = MD->isInstance();
 249       IsClassMethod = !IsInstanceMethod;
 250     }
 251     IsVariadic = FD->isVariadic();
 252     assert(involvesFunctionType());
 253     break;
 254   }
 255   case Decl::ObjCMethod: {
 256     const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(CommentDecl);
 257     Kind = FunctionKind;
 258     ParamVars = MD->parameters();
 259     ReturnType = MD->getReturnType();
 260     IsObjCMethod = true;
 261     IsInstanceMethod = MD->isInstanceMethod();
 262     IsClassMethod = !IsInstanceMethod;
 263     IsVariadic = MD->isVariadic();
 264     assert(involvesFunctionType());
 265     break;
 266   }
 267   case Decl::FunctionTemplate: {
 268     const FunctionTemplateDecl *FTD = cast<FunctionTemplateDecl>(CommentDecl);
 269     Kind = FunctionKind;
 270     TemplateKind = Template;
 271     const FunctionDecl *FD = FTD->getTemplatedDecl();
 272     ParamVars = FD->parameters();
 273     ReturnType = FD->getReturnType();
 274     TemplateParameters = FTD->getTemplateParameters();
 275     IsVariadic = FD->isVariadic();
 276     assert(involvesFunctionType());
 277     break;
 278   }
 279   case Decl::ClassTemplate: {
 280     const ClassTemplateDecl *CTD = cast<ClassTemplateDecl>(CommentDecl);
 281     Kind = ClassKind;
 282     TemplateKind = Template;
 283     TemplateParameters = CTD->getTemplateParameters();
 284     break;
 285   }
 286   case Decl::ClassTemplatePartialSpecialization: {
 287     const ClassTemplatePartialSpecializationDecl *CTPSD =
 288         cast<ClassTemplatePartialSpecializationDecl>(CommentDecl);
 289     Kind = ClassKind;
 290     TemplateKind = TemplatePartialSpecialization;
 291     TemplateParameters = CTPSD->getTemplateParameters();
 292     break;
 293   }
 294   case Decl::ClassTemplateSpecialization:
 295     Kind = ClassKind;
 296     TemplateKind = TemplateSpecialization;
 297     break;
 298   case Decl::Record:
 299   case Decl::CXXRecord:
 300     Kind = ClassKind;
 301     break;
 302   case Decl::Var:
 303     if (const VarTemplateDecl *VTD =
 304             cast<VarDecl>(CommentDecl)->getDescribedVarTemplate()) {
 305       TemplateKind = TemplateSpecialization;
 306       TemplateParameters = VTD->getTemplateParameters();
 307     }
 308     [[fallthrough]];
 309   case Decl::Field:
 310   case Decl::EnumConstant:
 311   case Decl::ObjCIvar:
 312   case Decl::ObjCAtDefsField:
 313   case Decl::ObjCProperty:
 314     if (const auto *VD = dyn_cast<DeclaratorDecl>(CommentDecl))
 315       TSI = VD->getTypeSourceInfo();
 316     else if (const auto *PD = dyn_cast<ObjCPropertyDecl>(CommentDecl))
 317       TSI = PD->getTypeSourceInfo();
 318     Kind = VariableKind;
 319     break;
 320   case Decl::VarTemplate: {
 321     const VarTemplateDecl *VTD = cast<VarTemplateDecl>(CommentDecl);
 322     Kind = VariableKind;
 323     TemplateKind = Template;
 324     TemplateParameters = VTD->getTemplateParameters();
 325     if (const VarDecl *VD = VTD->getTemplatedDecl())
 326       TSI = VD->getTypeSourceInfo();
 327     break;
 328   }
 329   case Decl::Namespace:
 330     Kind = NamespaceKind;
 331     break;
 332   case Decl::TypeAlias:
 333   case Decl::Typedef:
 334     Kind = TypedefKind;
 335     TSI = cast<TypedefNameDecl>(CommentDecl)->getTypeSourceInfo();
 336     break;
 337   case Decl::TypeAliasTemplate: {
 338     const TypeAliasTemplateDecl *TAT = cast<TypeAliasTemplateDecl>(CommentDecl);
 339     Kind = TypedefKind;
 340     TemplateKind = Template;
 341     TemplateParameters = TAT->getTemplateParameters();
 342     if (TypeAliasDecl *TAD = TAT->getTemplatedDecl())
 343       TSI = TAD->getTypeSourceInfo();
 344     break;
 345   }
 346   case Decl::Enum:
 347     Kind = EnumKind;
 348     break;
 349   }
 350
 351   // If the type is a typedef / using to something we consider a function,
 352   // extract arguments and return type.
 353   if (TSI) {
 354     TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
 355     FunctionTypeLoc FTL;
 356     if (getFunctionTypeLoc(TL, FTL)) {
 357       ParamVars = FTL.getParams();
 358       ReturnType = FTL.getReturnLoc().getType();
 359       if (const auto *FPT = dyn_cast<FunctionProtoType>(FTL.getTypePtr()))
 360         IsVariadic = FPT->isVariadic();
 361       assert(involvesFunctionType());
 362     }
 363   }
 364
 365   IsFilled = true;
 366 }
 367
 368 StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
 369   assert(isParamIndexValid());
 370   if (isVarArgParam())
 371     return "...";
 372   return FC->getDeclInfo()->ParamVars[getParamIndex()]->getName();
 373 }
 374
 375 StringRef TParamCommandComment::getParamName(const FullComment *FC) const {
 376   assert(isPositionValid());
 377   const TemplateParameterList *TPL = FC->getDeclInfo()->TemplateParameters;
 378   for (unsigned i = 0, e = getDepth(); i != e; ++i) {
 379     assert(TPL && "Unknown TemplateParameterList");
 380     if (i == e - 1)
 381       return TPL->getParam(getIndex(i))->getName();
 382     const NamedDecl *Param = TPL->getParam(getIndex(i));
 383     if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
 384       TPL = TTP->getTemplateParameters();
 385   }
 386   return "";
 387 }
 388
 389 } // end namespace comments
 390 } // end namespace clang
 391