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
18namespace clang {
19namespace 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.
32static_assert(std::is_trivially_destructible<DeclInfo>::value,
33              "DeclInfo should be trivially destructible!");
34
35const 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
49namespace {
50struct good {};
51struct bad {};
52
53template <typename T>
54good implements_child_begin_end(Comment::child_iterator (T::*)() const) {
55  return good();
56}
57
58LLVM_ATTRIBUTE_UNUSED
59static 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
67LLVM_ATTRIBUTE_UNUSED
68static 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
82Comment::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
96Comment::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
110bool 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
119bool 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
130static 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
158static 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
192const 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
204void 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  switch (K) {
225  default:
226    // Defaults are should be good for declarations we don't handle explicitly.
227    break;
228  case Decl::Function:
229  case Decl::CXXMethod:
230  case Decl::CXXConstructor:
231  case Decl::CXXDestructor:
232  case Decl::CXXConversion: {
233    const FunctionDecl *FD = cast<FunctionDecl>(CommentDecl);
234    Kind = FunctionKind;
235    ParamVars = FD->parameters();
236    ReturnType = FD->getReturnType();
237    unsigned NumLists = FD->getNumTemplateParameterLists();
238    if (NumLists != 0) {
239      TemplateKind = TemplateSpecialization;
240      TemplateParameters =
241          FD->getTemplateParameterList(NumLists - 1);
242    }
243
244    if (K == Decl::CXXMethod || K == Decl::CXXConstructor ||
245        K == Decl::CXXDestructor || K == Decl::CXXConversion) {
246      const CXXMethodDecl *MD = cast<CXXMethodDecl>(CommentDecl);
247      IsInstanceMethod = MD->isInstance();
248      IsClassMethod = !IsInstanceMethod;
249    }
250    break;
251  }
252  case Decl::ObjCMethod: {
253    const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(CommentDecl);
254    Kind = FunctionKind;
255    ParamVars = MD->parameters();
256    ReturnType = MD->getReturnType();
257    IsObjCMethod = true;
258    IsInstanceMethod = MD->isInstanceMethod();
259    IsClassMethod = !IsInstanceMethod;
260    break;
261  }
262  case Decl::FunctionTemplate: {
263    const FunctionTemplateDecl *FTD = cast<FunctionTemplateDecl>(CommentDecl);
264    Kind = FunctionKind;
265    TemplateKind = Template;
266    const FunctionDecl *FD = FTD->getTemplatedDecl();
267    ParamVars = FD->parameters();
268    ReturnType = FD->getReturnType();
269    TemplateParameters = FTD->getTemplateParameters();
270    break;
271  }
272  case Decl::ClassTemplate: {
273    const ClassTemplateDecl *CTD = cast<ClassTemplateDecl>(CommentDecl);
274    Kind = ClassKind;
275    TemplateKind = Template;
276    TemplateParameters = CTD->getTemplateParameters();
277    break;
278  }
279  case Decl::ClassTemplatePartialSpecialization: {
280    const ClassTemplatePartialSpecializationDecl *CTPSD =
281        cast<ClassTemplatePartialSpecializationDecl>(CommentDecl);
282    Kind = ClassKind;
283    TemplateKind = TemplatePartialSpecialization;
284    TemplateParameters = CTPSD->getTemplateParameters();
285    break;
286  }
287  case Decl::ClassTemplateSpecialization:
288    Kind = ClassKind;
289    TemplateKind = TemplateSpecialization;
290    break;
291  case Decl::Record:
292  case Decl::CXXRecord:
293    Kind = ClassKind;
294    break;
295  case Decl::Var:
296  case Decl::Field:
297  case Decl::EnumConstant:
298  case Decl::ObjCIvar:
299  case Decl::ObjCAtDefsField:
300  case Decl::ObjCProperty: {
301    const TypeSourceInfo *TSI;
302    if (const auto *VD = dyn_cast<DeclaratorDecl>(CommentDecl))
303      TSI = VD->getTypeSourceInfo();
304    else if (const auto *PD = dyn_cast<ObjCPropertyDecl>(CommentDecl))
305      TSI = PD->getTypeSourceInfo();
306    else
307      TSI = nullptr;
308    if (TSI) {
309      TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
310      FunctionTypeLoc FTL;
311      if (getFunctionTypeLoc(TL, FTL)) {
312        ParamVars = FTL.getParams();
313        ReturnType = FTL.getReturnLoc().getType();
314      }
315    }
316    Kind = VariableKind;
317    break;
318  }
319  case Decl::Namespace:
320    Kind = NamespaceKind;
321    break;
322  case Decl::TypeAlias:
323  case Decl::Typedef: {
324    Kind = TypedefKind;
325    // If this is a typedef / using to something we consider a function, extract
326    // arguments and return type.
327    const TypeSourceInfo *TSI =
328        K == Decl::Typedef
329            ? cast<TypedefDecl>(CommentDecl)->getTypeSourceInfo()
330            : cast<TypeAliasDecl>(CommentDecl)->getTypeSourceInfo();
331    if (!TSI)
332      break;
333    TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
334    FunctionTypeLoc FTL;
335    if (getFunctionTypeLoc(TL, FTL)) {
336      Kind = FunctionKind;
337      ParamVars = FTL.getParams();
338      ReturnType = FTL.getReturnLoc().getType();
339    }
340    break;
341  }
342  case Decl::TypeAliasTemplate: {
343    const TypeAliasTemplateDecl *TAT = cast<TypeAliasTemplateDecl>(CommentDecl);
344    Kind = TypedefKind;
345    TemplateKind = Template;
346    TemplateParameters = TAT->getTemplateParameters();
347    TypeAliasDecl *TAD = TAT->getTemplatedDecl();
348    if (!TAD)
349      break;
350
351    const TypeSourceInfo *TSI = TAD->getTypeSourceInfo();
352    if (!TSI)
353      break;
354    TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
355    FunctionTypeLoc FTL;
356    if (getFunctionTypeLoc(TL, FTL)) {
357      Kind = FunctionKind;
358      ParamVars = FTL.getParams();
359      ReturnType = FTL.getReturnLoc().getType();
360    }
361    break;
362  }
363  case Decl::Enum:
364    Kind = EnumKind;
365    break;
366  }
367
368  IsFilled = true;
369}
370
371StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
372  assert(isParamIndexValid());
373  if (isVarArgParam())
374    return "...";
375  return FC->getDeclInfo()->ParamVars[getParamIndex()]->getName();
376}
377
378StringRef TParamCommandComment::getParamName(const FullComment *FC) const {
379  assert(isPositionValid());
380  const TemplateParameterList *TPL = FC->getDeclInfo()->TemplateParameters;
381  for (unsigned i = 0, e = getDepth(); i != e; ++i) {
382    assert(TPL && "Unknown TemplateParameterList");
383    if (i == e - 1)
384      return TPL->getParam(getIndex(i))->getName();
385    const NamedDecl *Param = TPL->getParam(getIndex(i));
386    if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
387      TPL = TTP->getTemplateParameters();
388  }
389  return "";
390}
391
392} // end namespace comments
393} // end namespace clang
394
395