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<DeclInfo>::value,
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   for (StringRef::const_iterator I = Text.begin(), E = Text.end();
112        I != E; ++I) {
113     if (!clang::isWhitespace(*I))
114       return false;
115   }
116   return true;
117 }
118 
119 bool ParagraphComment::isWhitespaceNoCache() const {
120   for (child_iterator I = child_begin(), E = child_end(); I != E; ++I) {
121     if (const TextComment *TC = dyn_cast<TextComment>(*I)) {
122       if (!TC->isWhitespace())
123         return false;
124     } else
125       return false;
126   }
127   return true;
128 }
129 
130 static TypeLoc lookThroughTypedefOrTypeAliasLocs(TypeLoc &SrcTL) {
131   TypeLoc TL = SrcTL.IgnoreParens();
132 
133   // Look through attribute types.
134   if (AttributedTypeLoc AttributeTL = TL.getAs<AttributedTypeLoc>())
135     return AttributeTL.getModifiedLoc();
136   // Look through qualified types.
137   if (QualifiedTypeLoc QualifiedTL = TL.getAs<QualifiedTypeLoc>())
138     return QualifiedTL.getUnqualifiedLoc();
139   // Look through pointer types.
140   if (PointerTypeLoc PointerTL = TL.getAs<PointerTypeLoc>())
141     return PointerTL.getPointeeLoc().getUnqualifiedLoc();
142   // Look through reference types.
143   if (ReferenceTypeLoc ReferenceTL = TL.getAs<ReferenceTypeLoc>())
144     return ReferenceTL.getPointeeLoc().getUnqualifiedLoc();
145   // Look through adjusted types.
146   if (AdjustedTypeLoc ATL = TL.getAs<AdjustedTypeLoc>())
147     return ATL.getOriginalLoc();
148   if (BlockPointerTypeLoc BlockPointerTL = TL.getAs<BlockPointerTypeLoc>())
149     return BlockPointerTL.getPointeeLoc().getUnqualifiedLoc();
150   if (MemberPointerTypeLoc MemberPointerTL = TL.getAs<MemberPointerTypeLoc>())
151     return MemberPointerTL.getPointeeLoc().getUnqualifiedLoc();
152   if (ElaboratedTypeLoc ETL = TL.getAs<ElaboratedTypeLoc>())
153     return ETL.getNamedTypeLoc();
154 
155   return TL;
156 }
157 
158 static bool getFunctionTypeLoc(TypeLoc TL, FunctionTypeLoc &ResFTL) {
159   TypeLoc PrevTL;
160   while (PrevTL != TL) {
161     PrevTL = TL;
162     TL = lookThroughTypedefOrTypeAliasLocs(TL);
163   }
164 
165   if (FunctionTypeLoc FTL = TL.getAs<FunctionTypeLoc>()) {
166     ResFTL = FTL;
167     return true;
168   }
169 
170   if (TemplateSpecializationTypeLoc STL =
171           TL.getAs<TemplateSpecializationTypeLoc>()) {
172     // If we have a typedef to a template specialization with exactly one
173     // template argument of a function type, this looks like std::function,
174     // boost::function, or other function wrapper.  Treat these typedefs as
175     // functions.
176     if (STL.getNumArgs() != 1)
177       return false;
178     TemplateArgumentLoc MaybeFunction = STL.getArgLoc(0);
179     if (MaybeFunction.getArgument().getKind() != TemplateArgument::Type)
180       return false;
181     TypeSourceInfo *MaybeFunctionTSI = MaybeFunction.getTypeSourceInfo();
182     TypeLoc TL = MaybeFunctionTSI->getTypeLoc().getUnqualifiedLoc();
183     if (FunctionTypeLoc FTL = TL.getAs<FunctionTypeLoc>()) {
184       ResFTL = FTL;
185       return true;
186     }
187   }
188 
189   return false;
190 }
191 
192 const char *ParamCommandComment::getDirectionAsString(PassDirection D) {
193   switch (D) {
194   case ParamCommandComment::In:
195     return "[in]";
196   case ParamCommandComment::Out:
197     return "[out]";
198   case ParamCommandComment::InOut:
199     return "[in,out]";
200   }
201   llvm_unreachable("unknown PassDirection");
202 }
203 
204 void DeclInfo::fill() {
205   assert(!IsFilled);
206 
207   // Set defaults.
208   Kind = OtherKind;
209   TemplateKind = NotTemplate;
210   IsObjCMethod = false;
211   IsInstanceMethod = false;
212   IsClassMethod = false;
213   ParamVars = None;
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     break;
252   }
253   case Decl::ObjCMethod: {
254     const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(CommentDecl);
255     Kind = FunctionKind;
256     ParamVars = MD->parameters();
257     ReturnType = MD->getReturnType();
258     IsObjCMethod = true;
259     IsInstanceMethod = MD->isInstanceMethod();
260     IsClassMethod = !IsInstanceMethod;
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     break;
272   }
273   case Decl::ClassTemplate: {
274     const ClassTemplateDecl *CTD = cast<ClassTemplateDecl>(CommentDecl);
275     Kind = ClassKind;
276     TemplateKind = Template;
277     TemplateParameters = CTD->getTemplateParameters();
278     break;
279   }
280   case Decl::ClassTemplatePartialSpecialization: {
281     const ClassTemplatePartialSpecializationDecl *CTPSD =
282         cast<ClassTemplatePartialSpecializationDecl>(CommentDecl);
283     Kind = ClassKind;
284     TemplateKind = TemplatePartialSpecialization;
285     TemplateParameters = CTPSD->getTemplateParameters();
286     break;
287   }
288   case Decl::ClassTemplateSpecialization:
289     Kind = ClassKind;
290     TemplateKind = TemplateSpecialization;
291     break;
292   case Decl::Record:
293   case Decl::CXXRecord:
294     Kind = ClassKind;
295     break;
296   case Decl::Var:
297     if (const VarTemplateDecl *VTD =
298             cast<VarDecl>(CommentDecl)->getDescribedVarTemplate()) {
299       TemplateKind = TemplateSpecialization;
300       TemplateParameters = VTD->getTemplateParameters();
301     }
302     LLVM_FALLTHROUGH;
303   case Decl::Field:
304   case Decl::EnumConstant:
305   case Decl::ObjCIvar:
306   case Decl::ObjCAtDefsField:
307   case Decl::ObjCProperty:
308     if (const auto *VD = dyn_cast<DeclaratorDecl>(CommentDecl))
309       TSI = VD->getTypeSourceInfo();
310     else if (const auto *PD = dyn_cast<ObjCPropertyDecl>(CommentDecl))
311       TSI = PD->getTypeSourceInfo();
312     Kind = VariableKind;
313     break;
314   case Decl::VarTemplate: {
315     const VarTemplateDecl *VTD = cast<VarTemplateDecl>(CommentDecl);
316     Kind = VariableKind;
317     TemplateKind = Template;
318     TemplateParameters = VTD->getTemplateParameters();
319     if (const VarDecl *VD = VTD->getTemplatedDecl())
320       TSI = VD->getTypeSourceInfo();
321     break;
322   }
323   case Decl::Namespace:
324     Kind = NamespaceKind;
325     break;
326   case Decl::TypeAlias:
327   case Decl::Typedef:
328     Kind = TypedefKind;
329     TSI = cast<TypedefNameDecl>(CommentDecl)->getTypeSourceInfo();
330     break;
331   case Decl::TypeAliasTemplate: {
332     const TypeAliasTemplateDecl *TAT = cast<TypeAliasTemplateDecl>(CommentDecl);
333     Kind = TypedefKind;
334     TemplateKind = Template;
335     TemplateParameters = TAT->getTemplateParameters();
336     if (TypeAliasDecl *TAD = TAT->getTemplatedDecl())
337       TSI = TAD->getTypeSourceInfo();
338     break;
339   }
340   case Decl::Enum:
341     Kind = EnumKind;
342     break;
343   }
344 
345   // If the type is a typedef / using to something we consider a function,
346   // extract arguments and return type.
347   if (TSI) {
348     TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
349     FunctionTypeLoc FTL;
350     if (getFunctionTypeLoc(TL, FTL)) {
351       Kind = FunctionKind;
352       ParamVars = FTL.getParams();
353       ReturnType = FTL.getReturnLoc().getType();
354     }
355   }
356 
357   IsFilled = true;
358 }
359 
360 StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
361   assert(isParamIndexValid());
362   if (isVarArgParam())
363     return "...";
364   return FC->getDeclInfo()->ParamVars[getParamIndex()]->getName();
365 }
366 
367 StringRef TParamCommandComment::getParamName(const FullComment *FC) const {
368   assert(isPositionValid());
369   const TemplateParameterList *TPL = FC->getDeclInfo()->TemplateParameters;
370   for (unsigned i = 0, e = getDepth(); i != e; ++i) {
371     assert(TPL && "Unknown TemplateParameterList");
372     if (i == e - 1)
373       return TPL->getParam(getIndex(i))->getName();
374     const NamedDecl *Param = TPL->getParam(getIndex(i));
375     if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
376       TPL = TTP->getTemplateParameters();
377   }
378   return "";
379 }
380 
381 } // end namespace comments
382 } // end namespace clang
383 
384