CIndexUSRs.cpp revision cd9175d5013700b2827fc727fed2b53ea89be027 
1//===- CIndexUSR.cpp - Clang-C Source Indexing Library --------------------===//
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// This file implements the generation and use of USRs from CXEntities.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CIndexer.h"
15#include "CXCursor.h"
16#include "CXString.h"
17#include "clang/AST/DeclTemplate.h"
18#include "clang/AST/DeclVisitor.h"
19#include "clang/Frontend/ASTUnit.h"
20#include "clang/Lex/PreprocessingRecord.h"
21#include "llvm/ADT/SmallString.h"
22#include "llvm/Support/raw_ostream.h"
23
24using namespace clang;
25using namespace clang::cxstring;
26
27//===----------------------------------------------------------------------===//
28// USR generation.
29//===----------------------------------------------------------------------===//
30
31namespace {
32class USRGenerator : public DeclVisitor<USRGenerator> {
33  llvm::OwningPtr<llvm::SmallString<128> > OwnedBuf;
34  llvm::SmallVectorImpl<char> &Buf;
35  llvm::raw_svector_ostream Out;
36  bool IgnoreResults;
37  ASTUnit *AU;
38  bool generatedLoc;
39
40  llvm::DenseMap<const Type *, unsigned> TypeSubstitutions;
41
42public:
43  USRGenerator(const CXCursor *C = 0, llvm::SmallVectorImpl<char> *extBuf = 0)
44  : OwnedBuf(extBuf ? 0 : new llvm::SmallString<128>()),
45    Buf(extBuf ? *extBuf : *OwnedBuf.get()),
46    Out(Buf),
47    IgnoreResults(false),
48    AU(C ? cxcursor::getCursorASTUnit(*C) : 0),
49    generatedLoc(false)
50  {
51    // Add the USR space prefix.
52    Out << "c:";
53  }
54
55  llvm::StringRef str() {
56    return Out.str();
57  }
58
59  USRGenerator* operator->() { return this; }
60
61  template <typename T>
62  llvm::raw_svector_ostream &operator<<(const T &x) {
63    Out << x;
64    return Out;
65  }
66
67  bool ignoreResults() const { return IgnoreResults; }
68
69  // Visitation methods from generating USRs from AST elements.
70  void VisitDeclContext(DeclContext *D);
71  void VisitFieldDecl(FieldDecl *D);
72  void VisitFunctionDecl(FunctionDecl *D);
73  void VisitNamedDecl(NamedDecl *D);
74  void VisitNamespaceDecl(NamespaceDecl *D);
75  void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
76  void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
77  void VisitClassTemplateDecl(ClassTemplateDecl *D);
78  void VisitObjCClassDecl(ObjCClassDecl *CD);
79  void VisitObjCContainerDecl(ObjCContainerDecl *CD);
80  void VisitObjCForwardProtocolDecl(ObjCForwardProtocolDecl *P);
81  void VisitObjCMethodDecl(ObjCMethodDecl *MD);
82  void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
83  void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
84  void VisitTagDecl(TagDecl *D);
85  void VisitTypedefDecl(TypedefDecl *D);
86  void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
87  void VisitVarDecl(VarDecl *D);
88  void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
89  void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
90  void VisitLinkageSpecDecl(LinkageSpecDecl *D) {
91    IgnoreResults = true;
92  }
93  void VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
94    IgnoreResults = true;
95  }
96  void VisitUsingDecl(UsingDecl *D) {
97    IgnoreResults = true;
98  }
99  void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
100    IgnoreResults = true;
101  }
102  void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
103    IgnoreResults = true;
104  }
105
106  /// Generate the string component containing the location of the
107  ///  declaration.
108  bool GenLoc(const Decl *D);
109
110  /// String generation methods used both by the visitation methods
111  /// and from other clients that want to directly generate USRs.  These
112  /// methods do not construct complete USRs (which incorporate the parents
113  /// of an AST element), but only the fragments concerning the AST element
114  /// itself.
115
116  /// Generate a USR for an Objective-C class.
117  void GenObjCClass(llvm::StringRef cls);
118  /// Generate a USR for an Objective-C class category.
119  void GenObjCCategory(llvm::StringRef cls, llvm::StringRef cat);
120  /// Generate a USR fragment for an Objective-C instance variable.  The
121  /// complete USR can be created by concatenating the USR for the
122  /// encompassing class with this USR fragment.
123  void GenObjCIvar(llvm::StringRef ivar);
124  /// Generate a USR fragment for an Objective-C method.
125  void GenObjCMethod(llvm::StringRef sel, bool isInstanceMethod);
126  /// Generate a USR fragment for an Objective-C property.
127  void GenObjCProperty(llvm::StringRef prop);
128  /// Generate a USR for an Objective-C protocol.
129  void GenObjCProtocol(llvm::StringRef prot);
130
131  void VisitType(QualType T);
132  void VisitTemplateParameterList(const TemplateParameterList *Params);
133  void VisitTemplateName(TemplateName Name);
134  void VisitTemplateArgument(const TemplateArgument &Arg);
135
136  /// Emit a Decl's name using NamedDecl::printName() and return true if
137  ///  the decl had no name.
138  bool EmitDeclName(const NamedDecl *D);
139};
140
141} // end anonymous namespace
142
143//===----------------------------------------------------------------------===//
144// Generating USRs from ASTS.
145//===----------------------------------------------------------------------===//
146
147bool USRGenerator::EmitDeclName(const NamedDecl *D) {
148  Out.flush();
149  const unsigned startSize = Buf.size();
150  D->printName(Out);
151  Out.flush();
152  const unsigned endSize = Buf.size();
153  return startSize == endSize;
154}
155
156static bool InAnonymousNamespace(const Decl *D) {
157  if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(D->getDeclContext()))
158    return ND->isAnonymousNamespace();
159  return false;
160}
161
162static inline bool ShouldGenerateLocation(const NamedDecl *D) {
163  return D->getLinkage() != ExternalLinkage && !InAnonymousNamespace(D);
164}
165
166void USRGenerator::VisitDeclContext(DeclContext *DC) {
167  if (NamedDecl *D = dyn_cast<NamedDecl>(DC))
168    Visit(D);
169}
170
171void USRGenerator::VisitFieldDecl(FieldDecl *D) {
172  VisitDeclContext(D->getDeclContext());
173  Out << (isa<ObjCIvarDecl>(D) ? "@" : "@FI@");
174  if (EmitDeclName(D)) {
175    // Bit fields can be anonymous.
176    IgnoreResults = true;
177    return;
178  }
179}
180
181void USRGenerator::VisitFunctionDecl(FunctionDecl *D) {
182  if (ShouldGenerateLocation(D) && GenLoc(D))
183    return;
184
185  VisitDeclContext(D->getDeclContext());
186  if (FunctionTemplateDecl *FunTmpl = D->getDescribedFunctionTemplate()) {
187    Out << "@FT@";
188    VisitTemplateParameterList(FunTmpl->getTemplateParameters());
189  } else
190    Out << "@F@";
191  D->printName(Out);
192
193  ASTContext &Ctx = AU->getASTContext();
194  if (!Ctx.getLangOptions().CPlusPlus || D->isExternC())
195    return;
196
197  // Mangle in type information for the arguments.
198  for (FunctionDecl::param_iterator I = D->param_begin(), E = D->param_end();
199       I != E; ++I) {
200    Out << '#';
201    if (ParmVarDecl *PD = *I)
202      VisitType(PD->getType());
203  }
204  if (D->isVariadic())
205    Out << '.';
206  Out << '#';
207  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
208    if (MD->isStatic())
209      Out << 'S';
210    if (unsigned quals = MD->getTypeQualifiers())
211      Out << (char)('0' + quals);
212  }
213}
214
215void USRGenerator::VisitNamedDecl(NamedDecl *D) {
216  VisitDeclContext(D->getDeclContext());
217  Out << "@";
218
219  if (EmitDeclName(D)) {
220    // The string can be empty if the declaration has no name; e.g., it is
221    // the ParmDecl with no name for declaration of a function pointer type,
222    // e.g.: void  (*f)(void *);
223    // In this case, don't generate a USR.
224    IgnoreResults = true;
225  }
226}
227
228void USRGenerator::VisitVarDecl(VarDecl *D) {
229  // VarDecls can be declared 'extern' within a function or method body,
230  // but their enclosing DeclContext is the function, not the TU.  We need
231  // to check the storage class to correctly generate the USR.
232  if (ShouldGenerateLocation(D) && GenLoc(D))
233    return;
234
235  VisitDeclContext(D->getDeclContext());
236
237  // Variables always have simple names.
238  llvm::StringRef s = D->getName();
239
240  // The string can be empty if the declaration has no name; e.g., it is
241  // the ParmDecl with no name for declaration of a function pointer type, e.g.:
242  //    void  (*f)(void *);
243  // In this case, don't generate a USR.
244  if (s.empty())
245    IgnoreResults = true;
246  else
247    Out << '@' << s;
248}
249
250void USRGenerator::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
251  GenLoc(D);
252  return;
253}
254
255void USRGenerator::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
256  GenLoc(D);
257  return;
258}
259
260void USRGenerator::VisitNamespaceDecl(NamespaceDecl *D) {
261  if (D->isAnonymousNamespace()) {
262    Out << "@aN";
263    return;
264  }
265
266  VisitDeclContext(D->getDeclContext());
267  if (!IgnoreResults)
268    Out << "@N@" << D->getName();
269}
270
271void USRGenerator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
272  VisitFunctionDecl(D->getTemplatedDecl());
273}
274
275void USRGenerator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
276  VisitTagDecl(D->getTemplatedDecl());
277}
278
279void USRGenerator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
280  VisitDeclContext(D->getDeclContext());
281  if (!IgnoreResults)
282    Out << "@NA@" << D->getName();
283}
284
285void USRGenerator::VisitObjCMethodDecl(ObjCMethodDecl *D) {
286  // The USR for a method declared in a class extension or category is based on
287  // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
288  ObjCInterfaceDecl *ID = D->getClassInterface();
289  if (!ID) {
290    IgnoreResults = true;
291    return;
292  }
293  Visit(ID);
294
295  // Ideally we would use 'GenObjCMethod', but this is such a hot path
296  // for Objective-C code that we don't want to use
297  // DeclarationName::getAsString().
298  Out << (D->isInstanceMethod() ? "(im)" : "(cm)");
299  DeclarationName N(D->getSelector());
300  N.printName(Out);
301}
302
303void USRGenerator::VisitObjCClassDecl(ObjCClassDecl *D) {
304  // FIXME: @class declarations can refer to multiple classes.  We need
305  //  to be able to traverse these.
306  IgnoreResults = true;
307}
308
309void USRGenerator::VisitObjCForwardProtocolDecl(ObjCForwardProtocolDecl *D) {
310  // FIXME: @protocol declarations can refer to multiple protocols.  We need
311  //  to be able to traverse these.
312  IgnoreResults = true;
313}
314
315void USRGenerator::VisitObjCContainerDecl(ObjCContainerDecl *D) {
316  switch (D->getKind()) {
317    default:
318      assert(false && "Invalid ObjC container.");
319    case Decl::ObjCInterface:
320    case Decl::ObjCImplementation:
321      GenObjCClass(D->getName());
322      break;
323    case Decl::ObjCCategory: {
324      ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D);
325      ObjCInterfaceDecl *ID = CD->getClassInterface();
326      if (!ID) {
327        // Handle invalid code where the @interface might not
328        // have been specified.
329        // FIXME: We should be able to generate this USR even if the
330        // @interface isn't available.
331        IgnoreResults = true;
332        return;
333      }
334      // Specially handle class extensions, which are anonymous categories.
335      // We want to mangle in the location to uniquely distinguish them.
336      if (CD->IsClassExtension()) {
337        Out << "objc(ext)" << ID->getName() << '@';
338        GenLoc(CD);
339      }
340      else
341        GenObjCCategory(ID->getName(), CD->getName());
342
343      break;
344    }
345    case Decl::ObjCCategoryImpl: {
346      ObjCCategoryImplDecl *CD = cast<ObjCCategoryImplDecl>(D);
347      ObjCInterfaceDecl *ID = CD->getClassInterface();
348      if (!ID) {
349        // Handle invalid code where the @interface might not
350        // have been specified.
351        // FIXME: We should be able to generate this USR even if the
352        // @interface isn't available.
353        IgnoreResults = true;
354        return;
355      }
356      GenObjCCategory(ID->getName(), CD->getName());
357      break;
358    }
359    case Decl::ObjCProtocol:
360      GenObjCProtocol(cast<ObjCProtocolDecl>(D)->getName());
361      break;
362  }
363}
364
365void USRGenerator::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
366  Visit(cast<Decl>(D->getDeclContext()));
367  GenObjCProperty(D->getName());
368}
369
370void USRGenerator::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
371  if (ObjCPropertyDecl *PD = D->getPropertyDecl()) {
372    VisitObjCPropertyDecl(PD);
373    return;
374  }
375
376  IgnoreResults = true;
377}
378
379void USRGenerator::VisitTagDecl(TagDecl *D) {
380  // Add the location of the tag decl to handle resolution across
381  // translation units.
382  if (ShouldGenerateLocation(D) && GenLoc(D))
383    return;
384
385  D = D->getCanonicalDecl();
386  VisitDeclContext(D->getDeclContext());
387
388  bool AlreadyStarted = false;
389  if (CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(D)) {
390    if (ClassTemplateDecl *ClassTmpl = CXXRecord->getDescribedClassTemplate()) {
391      AlreadyStarted = true;
392
393      switch (D->getTagKind()) {
394      case TTK_Struct: Out << "@ST"; break;
395      case TTK_Class:  Out << "@CT"; break;
396      case TTK_Union:  Out << "@UT"; break;
397      case TTK_Enum: llvm_unreachable("enum template"); break;
398      }
399      VisitTemplateParameterList(ClassTmpl->getTemplateParameters());
400    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
401                = dyn_cast<ClassTemplatePartialSpecializationDecl>(CXXRecord)) {
402      AlreadyStarted = true;
403
404      switch (D->getTagKind()) {
405      case TTK_Struct: Out << "@SP"; break;
406      case TTK_Class:  Out << "@CP"; break;
407      case TTK_Union:  Out << "@UP"; break;
408      case TTK_Enum: llvm_unreachable("enum partial specialization"); break;
409      }
410      VisitTemplateParameterList(PartialSpec->getTemplateParameters());
411    }
412  }
413
414  if (!AlreadyStarted) {
415    switch (D->getTagKind()) {
416      case TTK_Struct: Out << "@S"; break;
417      case TTK_Class:  Out << "@C"; break;
418      case TTK_Union:  Out << "@U"; break;
419      case TTK_Enum:   Out << "@E"; break;
420    }
421  }
422
423  Out << '@';
424  Out.flush();
425  assert(Buf.size() > 0);
426  const unsigned off = Buf.size() - 1;
427
428  if (EmitDeclName(D)) {
429    if (const TypedefDecl *TD = D->getTypedefForAnonDecl()) {
430      Buf[off] = 'A';
431      Out << '@' << TD;
432    }
433    else
434      Buf[off] = 'a';
435  }
436
437  // For a class template specialization, mangle the template arguments.
438  if (ClassTemplateSpecializationDecl *Spec
439                              = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
440    const TemplateArgumentList &Args = Spec->getTemplateInstantiationArgs();
441    Out << '>';
442    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
443      Out << '#';
444      VisitTemplateArgument(Args.get(I));
445    }
446  }
447}
448
449void USRGenerator::VisitTypedefDecl(TypedefDecl *D) {
450  if (ShouldGenerateLocation(D) && GenLoc(D))
451    return;
452  DeclContext *DC = D->getDeclContext();
453  if (NamedDecl *DCN = dyn_cast<NamedDecl>(DC))
454    Visit(DCN);
455  Out << "@T@";
456  Out << D->getName();
457}
458
459void USRGenerator::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
460  GenLoc(D);
461  return;
462}
463
464bool USRGenerator::GenLoc(const Decl *D) {
465  if (generatedLoc)
466    return IgnoreResults;
467  generatedLoc = true;
468
469  const SourceManager &SM = AU->getSourceManager();
470  SourceLocation L = D->getLocStart();
471  if (L.isInvalid()) {
472    IgnoreResults = true;
473    return true;
474  }
475  L = SM.getInstantiationLoc(L);
476  const std::pair<FileID, unsigned> &Decomposed = SM.getDecomposedLoc(L);
477  const FileEntry *FE = SM.getFileEntryForID(Decomposed.first);
478  if (FE) {
479    Out << llvm::sys::path::filename(FE->getName());
480  }
481  else {
482    // This case really isn't interesting.
483    IgnoreResults = true;
484    return true;
485  }
486  // Use the offest into the FileID to represent the location.  Using
487  // a line/column can cause us to look back at the original source file,
488  // which is expensive.
489  Out << '@' << Decomposed.second;
490  return IgnoreResults;
491}
492
493void USRGenerator::VisitType(QualType T) {
494  // This method mangles in USR information for types.  It can possibly
495  // just reuse the naming-mangling logic used by codegen, although the
496  // requirements for USRs might not be the same.
497  ASTContext &Ctx = AU->getASTContext();
498
499  do {
500    T = Ctx.getCanonicalType(T);
501    Qualifiers Q = T.getQualifiers();
502    unsigned qVal = 0;
503    if (Q.hasConst())
504      qVal |= 0x1;
505    if (Q.hasVolatile())
506      qVal |= 0x2;
507    if (Q.hasRestrict())
508      qVal |= 0x4;
509    if(qVal)
510      Out << ((char) ('0' + qVal));
511
512    // Mangle in ObjC GC qualifiers?
513
514    if (const PackExpansionType *Expansion = T->getAs<PackExpansionType>()) {
515      Out << 'P';
516      T = Expansion->getPattern();
517    }
518
519    if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
520      unsigned char c = '\0';
521      switch (BT->getKind()) {
522        case BuiltinType::Void:
523          c = 'v'; break;
524        case BuiltinType::Bool:
525          c = 'b'; break;
526        case BuiltinType::Char_U:
527        case BuiltinType::UChar:
528          c = 'c'; break;
529        case BuiltinType::Char16:
530          c = 'q'; break;
531        case BuiltinType::Char32:
532          c = 'w'; break;
533        case BuiltinType::UShort:
534          c = 's'; break;
535        case BuiltinType::UInt:
536          c = 'i'; break;
537        case BuiltinType::ULong:
538          c = 'l'; break;
539        case BuiltinType::ULongLong:
540          c = 'k'; break;
541        case BuiltinType::UInt128:
542          c = 'j'; break;
543        case BuiltinType::Char_S:
544        case BuiltinType::SChar:
545          c = 'C'; break;
546        case BuiltinType::WChar_S:
547        case BuiltinType::WChar_U:
548          c = 'W'; break;
549        case BuiltinType::Short:
550          c = 'S'; break;
551        case BuiltinType::Int:
552          c = 'I'; break;
553        case BuiltinType::Long:
554          c = 'L'; break;
555        case BuiltinType::LongLong:
556          c = 'K'; break;
557        case BuiltinType::Int128:
558          c = 'J'; break;
559        case BuiltinType::Float:
560          c = 'f'; break;
561        case BuiltinType::Double:
562          c = 'd'; break;
563        case BuiltinType::LongDouble:
564          c = 'D'; break;
565        case BuiltinType::NullPtr:
566          c = 'n'; break;
567        case BuiltinType::Overload:
568        case BuiltinType::Dependent:
569        case BuiltinType::UndeducedAuto:
570          IgnoreResults = true;
571          return;
572        case BuiltinType::ObjCId:
573          c = 'o'; break;
574        case BuiltinType::ObjCClass:
575          c = 'O'; break;
576        case BuiltinType::ObjCSel:
577          c = 'e'; break;
578      }
579      Out << c;
580      return;
581    }
582
583    // If we have already seen this (non-built-in) type, use a substitution
584    // encoding.
585    llvm::DenseMap<const Type *, unsigned>::iterator Substitution
586      = TypeSubstitutions.find(T.getTypePtr());
587    if (Substitution != TypeSubstitutions.end()) {
588      Out << 'S' << Substitution->second << '_';
589      return;
590    } else {
591      // Record this as a substitution.
592      unsigned Number = TypeSubstitutions.size();
593      TypeSubstitutions[T.getTypePtr()] = Number;
594    }
595
596    if (const PointerType *PT = T->getAs<PointerType>()) {
597      Out << '*';
598      T = PT->getPointeeType();
599      continue;
600    }
601    if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
602      Out << '&';
603      T = RT->getPointeeType();
604      continue;
605    }
606    if (const FunctionProtoType *FT = T->getAs<FunctionProtoType>()) {
607      Out << 'F';
608      VisitType(FT->getResultType());
609      for (FunctionProtoType::arg_type_iterator
610            I = FT->arg_type_begin(), E = FT->arg_type_end(); I!=E; ++I) {
611        VisitType(*I);
612      }
613      if (FT->isVariadic())
614        Out << '.';
615      return;
616    }
617    if (const BlockPointerType *BT = T->getAs<BlockPointerType>()) {
618      Out << 'B';
619      T = BT->getPointeeType();
620      continue;
621    }
622    if (const ComplexType *CT = T->getAs<ComplexType>()) {
623      Out << '<';
624      T = CT->getElementType();
625      continue;
626    }
627    if (const TagType *TT = T->getAs<TagType>()) {
628      Out << '$';
629      VisitTagDecl(TT->getDecl());
630      return;
631    }
632    if (const TemplateTypeParmType *TTP = T->getAs<TemplateTypeParmType>()) {
633      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
634      return;
635    }
636    if (const TemplateSpecializationType *Spec
637                                    = T->getAs<TemplateSpecializationType>()) {
638      Out << '>';
639      VisitTemplateName(Spec->getTemplateName());
640      Out << Spec->getNumArgs();
641      for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
642        VisitTemplateArgument(Spec->getArg(I));
643      return;
644    }
645
646    // Unhandled type.
647    Out << ' ';
648    break;
649  } while (true);
650}
651
652void USRGenerator::VisitTemplateParameterList(
653                                         const TemplateParameterList *Params) {
654  if (!Params)
655    return;
656  Out << '>' << Params->size();
657  for (TemplateParameterList::const_iterator P = Params->begin(),
658                                          PEnd = Params->end();
659       P != PEnd; ++P) {
660    Out << '#';
661    if (isa<TemplateTypeParmDecl>(*P)) {
662      if (cast<TemplateTypeParmDecl>(*P)->isParameterPack())
663        Out<< 'p';
664      Out << 'T';
665      continue;
666    }
667
668    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
669      if (NTTP->isParameterPack())
670        Out << 'p';
671      Out << 'N';
672      VisitType(NTTP->getType());
673      continue;
674    }
675
676    TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*P);
677    if (TTP->isParameterPack())
678      Out << 'p';
679    Out << 't';
680    VisitTemplateParameterList(TTP->getTemplateParameters());
681  }
682}
683
684void USRGenerator::VisitTemplateName(TemplateName Name) {
685  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
686    if (TemplateTemplateParmDecl *TTP
687                              = dyn_cast<TemplateTemplateParmDecl>(Template)) {
688      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
689      return;
690    }
691
692    Visit(Template);
693    return;
694  }
695
696  // FIXME: Visit dependent template names.
697}
698
699void USRGenerator::VisitTemplateArgument(const TemplateArgument &Arg) {
700  switch (Arg.getKind()) {
701  case TemplateArgument::Null:
702    break;
703
704  case TemplateArgument::Declaration:
705    if (Decl *D = Arg.getAsDecl())
706      Visit(D);
707    break;
708
709  case TemplateArgument::TemplateExpansion:
710    Out << 'P'; // pack expansion of...
711    // Fall through
712  case TemplateArgument::Template:
713    VisitTemplateName(Arg.getAsTemplateOrTemplatePattern());
714    break;
715
716  case TemplateArgument::Expression:
717    // FIXME: Visit expressions.
718    break;
719
720  case TemplateArgument::Pack:
721    Out << 'p' << Arg.pack_size();
722    for (TemplateArgument::pack_iterator P = Arg.pack_begin(), PEnd = Arg.pack_end();
723         P != PEnd; ++P)
724      VisitTemplateArgument(*P);
725    break;
726
727  case TemplateArgument::Type:
728    VisitType(Arg.getAsType());
729    break;
730
731  case TemplateArgument::Integral:
732    Out << 'V';
733    VisitType(Arg.getIntegralType());
734    Out << *Arg.getAsIntegral();
735    break;
736  }
737}
738
739//===----------------------------------------------------------------------===//
740// General purpose USR generation methods.
741//===----------------------------------------------------------------------===//
742
743void USRGenerator::GenObjCClass(llvm::StringRef cls) {
744  Out << "objc(cs)" << cls;
745}
746
747void USRGenerator::GenObjCCategory(llvm::StringRef cls, llvm::StringRef cat) {
748  Out << "objc(cy)" << cls << '@' << cat;
749}
750
751void USRGenerator::GenObjCIvar(llvm::StringRef ivar) {
752  Out << '@' << ivar;
753}
754
755void USRGenerator::GenObjCMethod(llvm::StringRef meth, bool isInstanceMethod) {
756  Out << (isInstanceMethod ? "(im)" : "(cm)") << meth;
757}
758
759void USRGenerator::GenObjCProperty(llvm::StringRef prop) {
760  Out << "(py)" << prop;
761}
762
763void USRGenerator::GenObjCProtocol(llvm::StringRef prot) {
764  Out << "objc(pl)" << prot;
765}
766
767//===----------------------------------------------------------------------===//
768// API hooks.
769//===----------------------------------------------------------------------===//
770
771static inline llvm::StringRef extractUSRSuffix(llvm::StringRef s) {
772  return s.startswith("c:") ? s.substr(2) : "";
773}
774
775static CXString getDeclCursorUSR(const CXCursor &C) {
776  Decl *D = cxcursor::getCursorDecl(C);
777
778  // Don't generate USRs for things with invalid locations.
779  if (!D || D->getLocStart().isInvalid())
780    return createCXString("");
781
782  // Check if the cursor has 'NoLinkage'.
783  if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
784    switch (ND->getLinkage()) {
785      case ExternalLinkage:
786        // Generate USRs for all entities with external linkage.
787        break;
788      case NoLinkage:
789      case UniqueExternalLinkage:
790        // We allow enums, typedefs, and structs that have no linkage to
791        // have USRs that are anchored to the file they were defined in
792        // (e.g., the header).  This is a little gross, but in principal
793        // enums/anonymous structs/etc. defined in a common header file
794        // are referred to across multiple translation units.
795        if (isa<TagDecl>(ND) || isa<TypedefDecl>(ND) ||
796            isa<EnumConstantDecl>(ND) || isa<FieldDecl>(ND) ||
797            isa<VarDecl>(ND) || isa<NamespaceDecl>(ND))
798          break;
799        // Fall-through.
800      case InternalLinkage:
801        if (isa<FunctionDecl>(ND))
802          break;
803    }
804
805  CXTranslationUnit TU = cxcursor::getCursorTU(C);
806  if (!TU)
807    return createCXString("");
808
809  CXStringBuf *buf = cxstring::getCXStringBuf(TU);
810  if (!buf)
811    return createCXString("");
812
813  {
814    USRGenerator UG(&C, &buf->Data);
815    UG->Visit(D);
816
817    if (UG->ignoreResults()) {
818      disposeCXStringBuf(buf);
819      return createCXString("");
820    }
821  }
822  // Return the C-string, but don't make a copy since it is already in
823  // the string buffer.
824  buf->Data.push_back('\0');
825  return createCXString(buf);
826}
827
828extern "C" {
829
830CXString clang_getCursorUSR(CXCursor C) {
831  const CXCursorKind &K = clang_getCursorKind(C);
832
833  if (clang_isDeclaration(K))
834      return getDeclCursorUSR(C);
835
836  if (K == CXCursor_MacroDefinition) {
837    CXTranslationUnit TU = cxcursor::getCursorTU(C);
838    if (!TU)
839      return createCXString("");
840
841    CXStringBuf *buf = cxstring::getCXStringBuf(TU);
842    if (!buf)
843      return createCXString("");
844
845    {
846      USRGenerator UG(&C, &buf->Data);
847      UG << "macro@"
848        << cxcursor::getCursorMacroDefinition(C)->getName()->getNameStart();
849    }
850    buf->Data.push_back('\0');
851    return createCXString(buf);
852  }
853
854  return createCXString("");
855}
856
857CXString clang_constructUSR_ObjCIvar(const char *name, CXString classUSR) {
858  USRGenerator UG;
859  UG << extractUSRSuffix(clang_getCString(classUSR));
860  UG->GenObjCIvar(name);
861  return createCXString(UG.str(), true);
862}
863
864CXString clang_constructUSR_ObjCMethod(const char *name,
865                                       unsigned isInstanceMethod,
866                                       CXString classUSR) {
867  USRGenerator UG;
868  UG << extractUSRSuffix(clang_getCString(classUSR));
869  UG->GenObjCMethod(name, isInstanceMethod);
870  return createCXString(UG.str(), true);
871}
872
873CXString clang_constructUSR_ObjCClass(const char *name) {
874  USRGenerator UG;
875  UG->GenObjCClass(name);
876  return createCXString(UG.str(), true);
877}
878
879CXString clang_constructUSR_ObjCProtocol(const char *name) {
880  USRGenerator UG;
881  UG->GenObjCProtocol(name);
882  return createCXString(UG.str(), true);
883}
884
885CXString clang_constructUSR_ObjCCategory(const char *class_name,
886                                         const char *category_name) {
887  USRGenerator UG;
888  UG->GenObjCCategory(class_name, category_name);
889  return createCXString(UG.str(), true);
890}
891
892CXString clang_constructUSR_ObjCProperty(const char *property,
893                                         CXString classUSR) {
894  USRGenerator UG;
895  UG << extractUSRSuffix(clang_getCString(classUSR));
896  UG->GenObjCProperty(property);
897  return createCXString(UG.str(), true);
898}
899
900} // end extern "C"
901