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