xref: /freebsd/contrib/llvm-project/clang/lib/AST/Comment.cpp (revision a90b9d0159070121c221b966469c3e36d912bf82)
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 = std::nullopt;
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 
392