1//===- USRGeneration.cpp - Routines for USR generation --------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "clang/Index/USRGeneration.h"
11#include "clang/AST/ASTContext.h"
12#include "clang/AST/DeclTemplate.h"
13#include "clang/AST/DeclVisitor.h"
14#include "clang/Lex/PreprocessingRecord.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/Support/Path.h"
17#include "llvm/Support/raw_ostream.h"
18
19using namespace clang;
20using namespace clang::index;
21
22//===----------------------------------------------------------------------===//
23// USR generation.
24//===----------------------------------------------------------------------===//
25
26/// \returns true on error.
27static bool printLoc(llvm::raw_ostream &OS, SourceLocation Loc,
28                     const SourceManager &SM, bool IncludeOffset) {
29  if (Loc.isInvalid()) {
30    return true;
31  }
32  Loc = SM.getExpansionLoc(Loc);
33  const std::pair<FileID, unsigned> &Decomposed = SM.getDecomposedLoc(Loc);
34  const FileEntry *FE = SM.getFileEntryForID(Decomposed.first);
35  if (FE) {
36    OS << llvm::sys::path::filename(FE->getName());
37  } else {
38    // This case really isn't interesting.
39    return true;
40  }
41  if (IncludeOffset) {
42    // Use the offest into the FileID to represent the location.  Using
43    // a line/column can cause us to look back at the original source file,
44    // which is expensive.
45    OS << '@' << Decomposed.second;
46  }
47  return false;
48}
49
50namespace {
51class USRGenerator : public ConstDeclVisitor<USRGenerator> {
52  SmallVectorImpl<char> &Buf;
53  llvm::raw_svector_ostream Out;
54  bool IgnoreResults;
55  ASTContext *Context;
56  bool generatedLoc;
57
58  llvm::DenseMap<const Type *, unsigned> TypeSubstitutions;
59
60public:
61  explicit USRGenerator(ASTContext *Ctx, SmallVectorImpl<char> &Buf)
62  : Buf(Buf),
63    Out(Buf),
64    IgnoreResults(false),
65    Context(Ctx),
66    generatedLoc(false)
67  {
68    // Add the USR space prefix.
69    Out << getUSRSpacePrefix();
70  }
71
72  bool ignoreResults() const { return IgnoreResults; }
73
74  // Visitation methods from generating USRs from AST elements.
75  void VisitDeclContext(const DeclContext *D);
76  void VisitFieldDecl(const FieldDecl *D);
77  void VisitFunctionDecl(const FunctionDecl *D);
78  void VisitNamedDecl(const NamedDecl *D);
79  void VisitNamespaceDecl(const NamespaceDecl *D);
80  void VisitNamespaceAliasDecl(const NamespaceAliasDecl *D);
81  void VisitFunctionTemplateDecl(const FunctionTemplateDecl *D);
82  void VisitClassTemplateDecl(const ClassTemplateDecl *D);
83  void VisitObjCContainerDecl(const ObjCContainerDecl *CD);
84  void VisitObjCMethodDecl(const ObjCMethodDecl *MD);
85  void VisitObjCPropertyDecl(const ObjCPropertyDecl *D);
86  void VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D);
87  void VisitTagDecl(const TagDecl *D);
88  void VisitTypedefDecl(const TypedefDecl *D);
89  void VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *D);
90  void VisitVarDecl(const VarDecl *D);
91  void VisitNonTypeTemplateParmDecl(const NonTypeTemplateParmDecl *D);
92  void VisitTemplateTemplateParmDecl(const TemplateTemplateParmDecl *D);
93
94  void VisitLinkageSpecDecl(const LinkageSpecDecl *D) {
95    IgnoreResults = true;
96  }
97
98  void VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
99    IgnoreResults = true;
100  }
101
102  void VisitUsingDecl(const UsingDecl *D) {
103    IgnoreResults = true;
104  }
105
106  void VisitUnresolvedUsingValueDecl(const UnresolvedUsingValueDecl *D) {
107    IgnoreResults = true;
108  }
109
110  void VisitUnresolvedUsingTypenameDecl(const UnresolvedUsingTypenameDecl *D) {
111    IgnoreResults = true;
112  }
113
114  bool ShouldGenerateLocation(const NamedDecl *D);
115
116  bool isLocal(const NamedDecl *D) {
117    return D->getParentFunctionOrMethod() != nullptr;
118  }
119
120  /// Generate the string component containing the location of the
121  ///  declaration.
122  bool GenLoc(const Decl *D, bool IncludeOffset);
123
124  /// String generation methods used both by the visitation methods
125  /// and from other clients that want to directly generate USRs.  These
126  /// methods do not construct complete USRs (which incorporate the parents
127  /// of an AST element), but only the fragments concerning the AST element
128  /// itself.
129
130  /// Generate a USR for an Objective-C class.
131  void GenObjCClass(StringRef cls) {
132    generateUSRForObjCClass(cls, Out);
133  }
134
135  /// Generate a USR for an Objective-C class category.
136  void GenObjCCategory(StringRef cls, StringRef cat) {
137    generateUSRForObjCCategory(cls, cat, Out);
138  }
139
140  /// Generate a USR fragment for an Objective-C property.
141  void GenObjCProperty(StringRef prop) {
142    generateUSRForObjCProperty(prop, Out);
143  }
144
145  /// Generate a USR for an Objective-C protocol.
146  void GenObjCProtocol(StringRef prot) {
147    generateUSRForObjCProtocol(prot, Out);
148  }
149
150  void VisitType(QualType T);
151  void VisitTemplateParameterList(const TemplateParameterList *Params);
152  void VisitTemplateName(TemplateName Name);
153  void VisitTemplateArgument(const TemplateArgument &Arg);
154
155  /// Emit a Decl's name using NamedDecl::printName() and return true if
156  ///  the decl had no name.
157  bool EmitDeclName(const NamedDecl *D);
158};
159} // end anonymous namespace
160
161//===----------------------------------------------------------------------===//
162// Generating USRs from ASTS.
163//===----------------------------------------------------------------------===//
164
165bool USRGenerator::EmitDeclName(const NamedDecl *D) {
166  const unsigned startSize = Buf.size();
167  D->printName(Out);
168  const unsigned endSize = Buf.size();
169  return startSize == endSize;
170}
171
172bool USRGenerator::ShouldGenerateLocation(const NamedDecl *D) {
173  if (D->isExternallyVisible())
174    return false;
175  if (D->getParentFunctionOrMethod())
176    return true;
177  const SourceManager &SM = Context->getSourceManager();
178  return !SM.isInSystemHeader(D->getLocation());
179}
180
181void USRGenerator::VisitDeclContext(const DeclContext *DC) {
182  if (const NamedDecl *D = dyn_cast<NamedDecl>(DC))
183    Visit(D);
184}
185
186void USRGenerator::VisitFieldDecl(const FieldDecl *D) {
187  // The USR for an ivar declared in a class extension is based on the
188  // ObjCInterfaceDecl, not the ObjCCategoryDecl.
189  if (const ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
190    Visit(ID);
191  else
192    VisitDeclContext(D->getDeclContext());
193  Out << (isa<ObjCIvarDecl>(D) ? "@" : "@FI@");
194  if (EmitDeclName(D)) {
195    // Bit fields can be anonymous.
196    IgnoreResults = true;
197    return;
198  }
199}
200
201void USRGenerator::VisitFunctionDecl(const FunctionDecl *D) {
202  if (ShouldGenerateLocation(D) && GenLoc(D, /*IncludeOffset=*/isLocal(D)))
203    return;
204
205  VisitDeclContext(D->getDeclContext());
206  bool IsTemplate = false;
207  if (FunctionTemplateDecl *FunTmpl = D->getDescribedFunctionTemplate()) {
208    IsTemplate = true;
209    Out << "@FT@";
210    VisitTemplateParameterList(FunTmpl->getTemplateParameters());
211  } else
212    Out << "@F@";
213
214  PrintingPolicy Policy(Context->getLangOpts());
215  // Forward references can have different template argument names. Suppress the
216  // template argument names in constructors to make their USR more stable.
217  Policy.SuppressTemplateArgsInCXXConstructors = true;
218  D->getDeclName().print(Out, Policy);
219
220  ASTContext &Ctx = *Context;
221  if ((!Ctx.getLangOpts().CPlusPlus || D->isExternC()) &&
222      !D->hasAttr<OverloadableAttr>())
223    return;
224
225  if (const TemplateArgumentList *
226        SpecArgs = D->getTemplateSpecializationArgs()) {
227    Out << '<';
228    for (unsigned I = 0, N = SpecArgs->size(); I != N; ++I) {
229      Out << '#';
230      VisitTemplateArgument(SpecArgs->get(I));
231    }
232    Out << '>';
233  }
234
235  // Mangle in type information for the arguments.
236  for (auto PD : D->parameters()) {
237    Out << '#';
238    VisitType(PD->getType());
239  }
240  if (D->isVariadic())
241    Out << '.';
242  if (IsTemplate) {
243    // Function templates can be overloaded by return type, for example:
244    // \code
245    //   template <class T> typename T::A foo() {}
246    //   template <class T> typename T::B foo() {}
247    // \endcode
248    Out << '#';
249    VisitType(D->getReturnType());
250  }
251  Out << '#';
252  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
253    if (MD->isStatic())
254      Out << 'S';
255    if (unsigned quals = MD->getTypeQualifiers())
256      Out << (char)('0' + quals);
257    switch (MD->getRefQualifier()) {
258    case RQ_None: break;
259    case RQ_LValue: Out << '&'; break;
260    case RQ_RValue: Out << "&&"; break;
261    }
262  }
263}
264
265void USRGenerator::VisitNamedDecl(const NamedDecl *D) {
266  VisitDeclContext(D->getDeclContext());
267  Out << "@";
268
269  if (EmitDeclName(D)) {
270    // The string can be empty if the declaration has no name; e.g., it is
271    // the ParmDecl with no name for declaration of a function pointer type,
272    // e.g.: void  (*f)(void *);
273    // In this case, don't generate a USR.
274    IgnoreResults = true;
275  }
276}
277
278void USRGenerator::VisitVarDecl(const VarDecl *D) {
279  // VarDecls can be declared 'extern' within a function or method body,
280  // but their enclosing DeclContext is the function, not the TU.  We need
281  // to check the storage class to correctly generate the USR.
282  if (ShouldGenerateLocation(D) && GenLoc(D, /*IncludeOffset=*/isLocal(D)))
283    return;
284
285  VisitDeclContext(D->getDeclContext());
286
287  // Variables always have simple names.
288  StringRef s = D->getName();
289
290  // The string can be empty if the declaration has no name; e.g., it is
291  // the ParmDecl with no name for declaration of a function pointer type, e.g.:
292  //    void  (*f)(void *);
293  // In this case, don't generate a USR.
294  if (s.empty())
295    IgnoreResults = true;
296  else
297    Out << '@' << s;
298}
299
300void USRGenerator::VisitNonTypeTemplateParmDecl(
301                                        const NonTypeTemplateParmDecl *D) {
302  GenLoc(D, /*IncludeOffset=*/true);
303}
304
305void USRGenerator::VisitTemplateTemplateParmDecl(
306                                        const TemplateTemplateParmDecl *D) {
307  GenLoc(D, /*IncludeOffset=*/true);
308}
309
310void USRGenerator::VisitNamespaceDecl(const NamespaceDecl *D) {
311  if (D->isAnonymousNamespace()) {
312    Out << "@aN";
313    return;
314  }
315
316  VisitDeclContext(D->getDeclContext());
317  if (!IgnoreResults)
318    Out << "@N@" << D->getName();
319}
320
321void USRGenerator::VisitFunctionTemplateDecl(const FunctionTemplateDecl *D) {
322  VisitFunctionDecl(D->getTemplatedDecl());
323}
324
325void USRGenerator::VisitClassTemplateDecl(const ClassTemplateDecl *D) {
326  VisitTagDecl(D->getTemplatedDecl());
327}
328
329void USRGenerator::VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
330  VisitDeclContext(D->getDeclContext());
331  if (!IgnoreResults)
332    Out << "@NA@" << D->getName();
333}
334
335void USRGenerator::VisitObjCMethodDecl(const ObjCMethodDecl *D) {
336  const DeclContext *container = D->getDeclContext();
337  if (const ObjCProtocolDecl *pd = dyn_cast<ObjCProtocolDecl>(container)) {
338    Visit(pd);
339  }
340  else {
341    // The USR for a method declared in a class extension or category is based on
342    // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
343    const ObjCInterfaceDecl *ID = D->getClassInterface();
344    if (!ID) {
345      IgnoreResults = true;
346      return;
347    }
348    Visit(ID);
349  }
350  // Ideally we would use 'GenObjCMethod', but this is such a hot path
351  // for Objective-C code that we don't want to use
352  // DeclarationName::getAsString().
353  Out << (D->isInstanceMethod() ? "(im)" : "(cm)")
354      << DeclarationName(D->getSelector());
355}
356
357void USRGenerator::VisitObjCContainerDecl(const ObjCContainerDecl *D) {
358  switch (D->getKind()) {
359    default:
360      llvm_unreachable("Invalid ObjC container.");
361    case Decl::ObjCInterface:
362    case Decl::ObjCImplementation:
363      GenObjCClass(D->getName());
364      break;
365    case Decl::ObjCCategory: {
366      const ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D);
367      const ObjCInterfaceDecl *ID = CD->getClassInterface();
368      if (!ID) {
369        // Handle invalid code where the @interface might not
370        // have been specified.
371        // FIXME: We should be able to generate this USR even if the
372        // @interface isn't available.
373        IgnoreResults = true;
374        return;
375      }
376      // Specially handle class extensions, which are anonymous categories.
377      // We want to mangle in the location to uniquely distinguish them.
378      if (CD->IsClassExtension()) {
379        Out << "objc(ext)" << ID->getName() << '@';
380        GenLoc(CD, /*IncludeOffset=*/true);
381      }
382      else
383        GenObjCCategory(ID->getName(), CD->getName());
384
385      break;
386    }
387    case Decl::ObjCCategoryImpl: {
388      const ObjCCategoryImplDecl *CD = cast<ObjCCategoryImplDecl>(D);
389      const ObjCInterfaceDecl *ID = CD->getClassInterface();
390      if (!ID) {
391        // Handle invalid code where the @interface might not
392        // have been specified.
393        // FIXME: We should be able to generate this USR even if the
394        // @interface isn't available.
395        IgnoreResults = true;
396        return;
397      }
398      GenObjCCategory(ID->getName(), CD->getName());
399      break;
400    }
401    case Decl::ObjCProtocol:
402      GenObjCProtocol(cast<ObjCProtocolDecl>(D)->getName());
403      break;
404  }
405}
406
407void USRGenerator::VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
408  // The USR for a property declared in a class extension or category is based
409  // on the ObjCInterfaceDecl, not the ObjCCategoryDecl.
410  if (const ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
411    Visit(ID);
412  else
413    Visit(cast<Decl>(D->getDeclContext()));
414  GenObjCProperty(D->getName());
415}
416
417void USRGenerator::VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
418  if (ObjCPropertyDecl *PD = D->getPropertyDecl()) {
419    VisitObjCPropertyDecl(PD);
420    return;
421  }
422
423  IgnoreResults = true;
424}
425
426void USRGenerator::VisitTagDecl(const TagDecl *D) {
427  // Add the location of the tag decl to handle resolution across
428  // translation units.
429  if (!isa<EnumDecl>(D) &&
430      ShouldGenerateLocation(D) && GenLoc(D, /*IncludeOffset=*/isLocal(D)))
431    return;
432
433  D = D->getCanonicalDecl();
434  VisitDeclContext(D->getDeclContext());
435
436  bool AlreadyStarted = false;
437  if (const CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(D)) {
438    if (ClassTemplateDecl *ClassTmpl = CXXRecord->getDescribedClassTemplate()) {
439      AlreadyStarted = true;
440
441      switch (D->getTagKind()) {
442      case TTK_Interface:
443      case TTK_Class:
444      case TTK_Struct: Out << "@ST"; break;
445      case TTK_Union:  Out << "@UT"; break;
446      case TTK_Enum: llvm_unreachable("enum template");
447      }
448      VisitTemplateParameterList(ClassTmpl->getTemplateParameters());
449    } else if (const ClassTemplatePartialSpecializationDecl *PartialSpec
450                = dyn_cast<ClassTemplatePartialSpecializationDecl>(CXXRecord)) {
451      AlreadyStarted = true;
452
453      switch (D->getTagKind()) {
454      case TTK_Interface:
455      case TTK_Class:
456      case TTK_Struct: Out << "@SP"; break;
457      case TTK_Union:  Out << "@UP"; break;
458      case TTK_Enum: llvm_unreachable("enum partial specialization");
459      }
460      VisitTemplateParameterList(PartialSpec->getTemplateParameters());
461    }
462  }
463
464  if (!AlreadyStarted) {
465    switch (D->getTagKind()) {
466      case TTK_Interface:
467      case TTK_Class:
468      case TTK_Struct: Out << "@S"; break;
469      case TTK_Union:  Out << "@U"; break;
470      case TTK_Enum:   Out << "@E"; break;
471    }
472  }
473
474  Out << '@';
475  assert(Buf.size() > 0);
476  const unsigned off = Buf.size() - 1;
477
478  if (EmitDeclName(D)) {
479    if (const TypedefNameDecl *TD = D->getTypedefNameForAnonDecl()) {
480      Buf[off] = 'A';
481      Out << '@' << *TD;
482    }
483  else {
484    if (D->isEmbeddedInDeclarator() && !D->isFreeStanding()) {
485      printLoc(Out, D->getLocation(), Context->getSourceManager(), true);
486    } else {
487      Buf[off] = 'a';
488      if (auto *ED = dyn_cast<EnumDecl>(D)) {
489        // Distinguish USRs of anonymous enums by using their first enumerator.
490        auto enum_range = ED->enumerators();
491        if (enum_range.begin() != enum_range.end()) {
492          Out << '@' << **enum_range.begin();
493        }
494      }
495    }
496  }
497  }
498
499  // For a class template specialization, mangle the template arguments.
500  if (const ClassTemplateSpecializationDecl *Spec
501                              = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
502    const TemplateArgumentList &Args = Spec->getTemplateInstantiationArgs();
503    Out << '>';
504    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
505      Out << '#';
506      VisitTemplateArgument(Args.get(I));
507    }
508  }
509}
510
511void USRGenerator::VisitTypedefDecl(const TypedefDecl *D) {
512  if (ShouldGenerateLocation(D) && GenLoc(D, /*IncludeOffset=*/isLocal(D)))
513    return;
514  const DeclContext *DC = D->getDeclContext();
515  if (const NamedDecl *DCN = dyn_cast<NamedDecl>(DC))
516    Visit(DCN);
517  Out << "@T@";
518  Out << D->getName();
519}
520
521void USRGenerator::VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *D) {
522  GenLoc(D, /*IncludeOffset=*/true);
523}
524
525bool USRGenerator::GenLoc(const Decl *D, bool IncludeOffset) {
526  if (generatedLoc)
527    return IgnoreResults;
528  generatedLoc = true;
529
530  // Guard against null declarations in invalid code.
531  if (!D) {
532    IgnoreResults = true;
533    return true;
534  }
535
536  // Use the location of canonical decl.
537  D = D->getCanonicalDecl();
538
539  IgnoreResults =
540      IgnoreResults || printLoc(Out, D->getLocStart(),
541                                Context->getSourceManager(), IncludeOffset);
542
543  return IgnoreResults;
544}
545
546void USRGenerator::VisitType(QualType T) {
547  // This method mangles in USR information for types.  It can possibly
548  // just reuse the naming-mangling logic used by codegen, although the
549  // requirements for USRs might not be the same.
550  ASTContext &Ctx = *Context;
551
552  do {
553    T = Ctx.getCanonicalType(T);
554    Qualifiers Q = T.getQualifiers();
555    unsigned qVal = 0;
556    if (Q.hasConst())
557      qVal |= 0x1;
558    if (Q.hasVolatile())
559      qVal |= 0x2;
560    if (Q.hasRestrict())
561      qVal |= 0x4;
562    if(qVal)
563      Out << ((char) ('0' + qVal));
564
565    // Mangle in ObjC GC qualifiers?
566
567    if (const PackExpansionType *Expansion = T->getAs<PackExpansionType>()) {
568      Out << 'P';
569      T = Expansion->getPattern();
570    }
571
572    if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
573      unsigned char c = '\0';
574      switch (BT->getKind()) {
575        case BuiltinType::Void:
576          c = 'v'; break;
577        case BuiltinType::Bool:
578          c = 'b'; break;
579        case BuiltinType::UChar:
580          c = 'c'; break;
581        case BuiltinType::Char16:
582          c = 'q'; break;
583        case BuiltinType::Char32:
584          c = 'w'; break;
585        case BuiltinType::UShort:
586          c = 's'; break;
587        case BuiltinType::UInt:
588          c = 'i'; break;
589        case BuiltinType::ULong:
590          c = 'l'; break;
591        case BuiltinType::ULongLong:
592          c = 'k'; break;
593        case BuiltinType::UInt128:
594          c = 'j'; break;
595        case BuiltinType::Char_U:
596        case BuiltinType::Char_S:
597          c = 'C'; break;
598        case BuiltinType::SChar:
599          c = 'r'; break;
600        case BuiltinType::WChar_S:
601        case BuiltinType::WChar_U:
602          c = 'W'; break;
603        case BuiltinType::Short:
604          c = 'S'; break;
605        case BuiltinType::Int:
606          c = 'I'; break;
607        case BuiltinType::Long:
608          c = 'L'; break;
609        case BuiltinType::LongLong:
610          c = 'K'; break;
611        case BuiltinType::Int128:
612          c = 'J'; break;
613        case BuiltinType::Half:
614          c = 'h'; break;
615        case BuiltinType::Float:
616          c = 'f'; break;
617        case BuiltinType::Double:
618          c = 'd'; break;
619        case BuiltinType::LongDouble:
620          c = 'D'; break;
621        case BuiltinType::Float128:
622          c = 'Q'; break;
623        case BuiltinType::NullPtr:
624          c = 'n'; break;
625#define BUILTIN_TYPE(Id, SingletonId)
626#define PLACEHOLDER_TYPE(Id, SingletonId) case BuiltinType::Id:
627#include "clang/AST/BuiltinTypes.def"
628        case BuiltinType::Dependent:
629#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
630        case BuiltinType::Id:
631#include "clang/Basic/OpenCLImageTypes.def"
632        case BuiltinType::OCLEvent:
633        case BuiltinType::OCLClkEvent:
634        case BuiltinType::OCLQueue:
635        case BuiltinType::OCLNDRange:
636        case BuiltinType::OCLReserveID:
637        case BuiltinType::OCLSampler:
638          IgnoreResults = true;
639          return;
640        case BuiltinType::ObjCId:
641          c = 'o'; break;
642        case BuiltinType::ObjCClass:
643          c = 'O'; break;
644        case BuiltinType::ObjCSel:
645          c = 'e'; break;
646      }
647      Out << c;
648      return;
649    }
650
651    // If we have already seen this (non-built-in) type, use a substitution
652    // encoding.
653    llvm::DenseMap<const Type *, unsigned>::iterator Substitution
654      = TypeSubstitutions.find(T.getTypePtr());
655    if (Substitution != TypeSubstitutions.end()) {
656      Out << 'S' << Substitution->second << '_';
657      return;
658    } else {
659      // Record this as a substitution.
660      unsigned Number = TypeSubstitutions.size();
661      TypeSubstitutions[T.getTypePtr()] = Number;
662    }
663
664    if (const PointerType *PT = T->getAs<PointerType>()) {
665      Out << '*';
666      T = PT->getPointeeType();
667      continue;
668    }
669    if (const ObjCObjectPointerType *OPT = T->getAs<ObjCObjectPointerType>()) {
670      Out << '*';
671      T = OPT->getPointeeType();
672      continue;
673    }
674    if (const RValueReferenceType *RT = T->getAs<RValueReferenceType>()) {
675      Out << "&&";
676      T = RT->getPointeeType();
677      continue;
678    }
679    if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
680      Out << '&';
681      T = RT->getPointeeType();
682      continue;
683    }
684    if (const FunctionProtoType *FT = T->getAs<FunctionProtoType>()) {
685      Out << 'F';
686      VisitType(FT->getReturnType());
687      for (const auto &I : FT->param_types())
688        VisitType(I);
689      if (FT->isVariadic())
690        Out << '.';
691      return;
692    }
693    if (const BlockPointerType *BT = T->getAs<BlockPointerType>()) {
694      Out << 'B';
695      T = BT->getPointeeType();
696      continue;
697    }
698    if (const ComplexType *CT = T->getAs<ComplexType>()) {
699      Out << '<';
700      T = CT->getElementType();
701      continue;
702    }
703    if (const TagType *TT = T->getAs<TagType>()) {
704      Out << '$';
705      VisitTagDecl(TT->getDecl());
706      return;
707    }
708    if (const ObjCInterfaceType *OIT = T->getAs<ObjCInterfaceType>()) {
709      Out << '$';
710      VisitObjCInterfaceDecl(OIT->getDecl());
711      return;
712    }
713    if (const ObjCObjectType *OIT = T->getAs<ObjCObjectType>()) {
714      Out << 'Q';
715      VisitType(OIT->getBaseType());
716      for (auto *Prot : OIT->getProtocols())
717        VisitObjCProtocolDecl(Prot);
718      return;
719    }
720    if (const TemplateTypeParmType *TTP = T->getAs<TemplateTypeParmType>()) {
721      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
722      return;
723    }
724    if (const TemplateSpecializationType *Spec
725                                    = T->getAs<TemplateSpecializationType>()) {
726      Out << '>';
727      VisitTemplateName(Spec->getTemplateName());
728      Out << Spec->getNumArgs();
729      for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
730        VisitTemplateArgument(Spec->getArg(I));
731      return;
732    }
733    if (const DependentNameType *DNT = T->getAs<DependentNameType>()) {
734      Out << '^';
735      // FIXME: Encode the qualifier, don't just print it.
736      PrintingPolicy PO(Ctx.getLangOpts());
737      PO.SuppressTagKeyword = true;
738      PO.SuppressUnwrittenScope = true;
739      PO.ConstantArraySizeAsWritten = false;
740      PO.AnonymousTagLocations = false;
741      DNT->getQualifier()->print(Out, PO);
742      Out << ':' << DNT->getIdentifier()->getName();
743      return;
744    }
745    if (const InjectedClassNameType *InjT = T->getAs<InjectedClassNameType>()) {
746      T = InjT->getInjectedSpecializationType();
747      continue;
748    }
749
750    // Unhandled type.
751    Out << ' ';
752    break;
753  } while (true);
754}
755
756void USRGenerator::VisitTemplateParameterList(
757                                         const TemplateParameterList *Params) {
758  if (!Params)
759    return;
760  Out << '>' << Params->size();
761  for (TemplateParameterList::const_iterator P = Params->begin(),
762                                          PEnd = Params->end();
763       P != PEnd; ++P) {
764    Out << '#';
765    if (isa<TemplateTypeParmDecl>(*P)) {
766      if (cast<TemplateTypeParmDecl>(*P)->isParameterPack())
767        Out<< 'p';
768      Out << 'T';
769      continue;
770    }
771
772    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
773      if (NTTP->isParameterPack())
774        Out << 'p';
775      Out << 'N';
776      VisitType(NTTP->getType());
777      continue;
778    }
779
780    TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*P);
781    if (TTP->isParameterPack())
782      Out << 'p';
783    Out << 't';
784    VisitTemplateParameterList(TTP->getTemplateParameters());
785  }
786}
787
788void USRGenerator::VisitTemplateName(TemplateName Name) {
789  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
790    if (TemplateTemplateParmDecl *TTP
791                              = dyn_cast<TemplateTemplateParmDecl>(Template)) {
792      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
793      return;
794    }
795
796    Visit(Template);
797    return;
798  }
799
800  // FIXME: Visit dependent template names.
801}
802
803void USRGenerator::VisitTemplateArgument(const TemplateArgument &Arg) {
804  switch (Arg.getKind()) {
805  case TemplateArgument::Null:
806    break;
807
808  case TemplateArgument::Declaration:
809    Visit(Arg.getAsDecl());
810    break;
811
812  case TemplateArgument::NullPtr:
813    break;
814
815  case TemplateArgument::TemplateExpansion:
816    Out << 'P'; // pack expansion of...
817    // Fall through
818  case TemplateArgument::Template:
819    VisitTemplateName(Arg.getAsTemplateOrTemplatePattern());
820    break;
821
822  case TemplateArgument::Expression:
823    // FIXME: Visit expressions.
824    break;
825
826  case TemplateArgument::Pack:
827    Out << 'p' << Arg.pack_size();
828    for (const auto &P : Arg.pack_elements())
829      VisitTemplateArgument(P);
830    break;
831
832  case TemplateArgument::Type:
833    VisitType(Arg.getAsType());
834    break;
835
836  case TemplateArgument::Integral:
837    Out << 'V';
838    VisitType(Arg.getIntegralType());
839    Out << Arg.getAsIntegral();
840    break;
841  }
842}
843
844//===----------------------------------------------------------------------===//
845// USR generation functions.
846//===----------------------------------------------------------------------===//
847
848void clang::index::generateUSRForObjCClass(StringRef Cls, raw_ostream &OS) {
849  OS << "objc(cs)" << Cls;
850}
851
852void clang::index::generateUSRForObjCCategory(StringRef Cls, StringRef Cat,
853                                              raw_ostream &OS) {
854  OS << "objc(cy)" << Cls << '@' << Cat;
855}
856
857void clang::index::generateUSRForObjCIvar(StringRef Ivar, raw_ostream &OS) {
858  OS << '@' << Ivar;
859}
860
861void clang::index::generateUSRForObjCMethod(StringRef Sel,
862                                            bool IsInstanceMethod,
863                                            raw_ostream &OS) {
864  OS << (IsInstanceMethod ? "(im)" : "(cm)") << Sel;
865}
866
867void clang::index::generateUSRForObjCProperty(StringRef Prop, raw_ostream &OS) {
868  OS << "(py)" << Prop;
869}
870
871void clang::index::generateUSRForObjCProtocol(StringRef Prot, raw_ostream &OS) {
872  OS << "objc(pl)" << Prot;
873}
874
875bool clang::index::generateUSRForDecl(const Decl *D,
876                                      SmallVectorImpl<char> &Buf) {
877  // Don't generate USRs for things with invalid locations.
878  if (!D || D->getLocStart().isInvalid())
879    return true;
880
881  USRGenerator UG(&D->getASTContext(), Buf);
882  UG.Visit(D);
883  return UG.ignoreResults();
884}
885
886bool clang::index::generateUSRForMacro(const MacroDefinitionRecord *MD,
887                                       const SourceManager &SM,
888                                       SmallVectorImpl<char> &Buf) {
889  // Don't generate USRs for things with invalid locations.
890  if (!MD || MD->getLocation().isInvalid())
891    return true;
892
893  llvm::raw_svector_ostream Out(Buf);
894
895  // Assume that system headers are sane.  Don't put source location
896  // information into the USR if the macro comes from a system header.
897  SourceLocation Loc = MD->getLocation();
898  bool ShouldGenerateLocation = !SM.isInSystemHeader(Loc);
899
900  Out << getUSRSpacePrefix();
901  if (ShouldGenerateLocation)
902    printLoc(Out, Loc, SM, /*IncludeOffset=*/true);
903  Out << "@macro@";
904  Out << MD->getName()->getName();
905  return false;
906}
907