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 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  return llvm::all_of(Text, clang::isWhitespace);
112}
113
114bool 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
125static 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
153static 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
187const 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
199void 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 = std::nullopt;
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    [[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
364StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
365  assert(isParamIndexValid());
366  if (isVarArgParam())
367    return "...";
368  return FC->getDeclInfo()->ParamVars[getParamIndex()]->getName();
369}
370
371StringRef 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