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_v<DeclInfo>,
33              "DeclInfo should be trivially destructible!");
34
35const 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
50namespace {
51struct good {};
52struct bad {};
53
54template <typename T>
55good implements_child_begin_end(Comment::child_iterator (T::*)() const) {
56  return good();
57}
58
59LLVM_ATTRIBUTE_UNUSED
60static 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
68LLVM_ATTRIBUTE_UNUSED
69static 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
83Comment::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
98Comment::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
113bool TextComment::isWhitespaceNoCache() const {
114  return llvm::all_of(Text, clang::isWhitespace);
115}
116
117bool 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
128static 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
156static 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
190const char *
191ParamCommandComment::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
203void 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
368StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
369  assert(isParamIndexValid());
370  if (isVarArgParam())
371    return "...";
372  return FC->getDeclInfo()->ParamVars[getParamIndex()]->getName();
373}
374
375StringRef 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