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   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 = None;
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     LLVM_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 
388