CIndexUSRs.cpp revision 36d592718ff342f762e32cbde73d1113f88cb275 
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  OwningPtr<SmallString<128> > OwnedBuf;
34  SmallVectorImpl<char> &Buf;
35  llvm::raw_svector_ostream Out;
36  bool IgnoreResults;
37  ASTContext *Context;
38  bool generatedLoc;
39
40  llvm::DenseMap<const Type *, unsigned> TypeSubstitutions;
41
42public:
43  explicit USRGenerator(ASTContext *Ctx = 0, SmallVectorImpl<char> *extBuf = 0)
44  : OwnedBuf(extBuf ? 0 : new SmallString<128>()),
45    Buf(extBuf ? *extBuf : *OwnedBuf.get()),
46    Out(Buf),
47    IgnoreResults(false),
48    Context(Ctx),
49    generatedLoc(false)
50  {
51    // Add the USR space prefix.
52    Out << "c:";
53  }
54
55  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 VisitObjCContainerDecl(ObjCContainerDecl *CD);
79  void VisitObjCMethodDecl(ObjCMethodDecl *MD);
80  void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
81  void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
82  void VisitTagDecl(TagDecl *D);
83  void VisitTypedefDecl(TypedefDecl *D);
84  void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
85  void VisitVarDecl(VarDecl *D);
86  void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
87  void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
88  void VisitLinkageSpecDecl(LinkageSpecDecl *D) {
89    IgnoreResults = true;
90  }
91  void VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
92    IgnoreResults = true;
93  }
94  void VisitUsingDecl(UsingDecl *D) {
95    IgnoreResults = true;
96  }
97  void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
98    IgnoreResults = true;
99  }
100  void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
101    IgnoreResults = true;
102  }
103
104  /// Generate the string component containing the location of the
105  ///  declaration.
106  bool GenLoc(const Decl *D);
107
108  /// String generation methods used both by the visitation methods
109  /// and from other clients that want to directly generate USRs.  These
110  /// methods do not construct complete USRs (which incorporate the parents
111  /// of an AST element), but only the fragments concerning the AST element
112  /// itself.
113
114  /// Generate a USR for an Objective-C class.
115  void GenObjCClass(StringRef cls);
116  /// Generate a USR for an Objective-C class category.
117  void GenObjCCategory(StringRef cls, StringRef cat);
118  /// Generate a USR fragment for an Objective-C instance variable.  The
119  /// complete USR can be created by concatenating the USR for the
120  /// encompassing class with this USR fragment.
121  void GenObjCIvar(StringRef ivar);
122  /// Generate a USR fragment for an Objective-C method.
123  void GenObjCMethod(StringRef sel, bool isInstanceMethod);
124  /// Generate a USR fragment for an Objective-C property.
125  void GenObjCProperty(StringRef prop);
126  /// Generate a USR for an Objective-C protocol.
127  void GenObjCProtocol(StringRef prot);
128
129  void VisitType(QualType T);
130  void VisitTemplateParameterList(const TemplateParameterList *Params);
131  void VisitTemplateName(TemplateName Name);
132  void VisitTemplateArgument(const TemplateArgument &Arg);
133
134  /// Emit a Decl's name using NamedDecl::printName() and return true if
135  ///  the decl had no name.
136  bool EmitDeclName(const NamedDecl *D);
137};
138
139} // end anonymous namespace
140
141//===----------------------------------------------------------------------===//
142// Generating USRs from ASTS.
143//===----------------------------------------------------------------------===//
144
145bool USRGenerator::EmitDeclName(const NamedDecl *D) {
146  Out.flush();
147  const unsigned startSize = Buf.size();
148  D->printName(Out);
149  Out.flush();
150  const unsigned endSize = Buf.size();
151  return startSize == endSize;
152}
153
154static bool InAnonymousNamespace(const Decl *D) {
155  if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(D->getDeclContext()))
156    return ND->isAnonymousNamespace();
157  return false;
158}
159
160static inline bool ShouldGenerateLocation(const NamedDecl *D) {
161  return D->getLinkage() != ExternalLinkage && !InAnonymousNamespace(D);
162}
163
164void USRGenerator::VisitDeclContext(DeclContext *DC) {
165  if (NamedDecl *D = dyn_cast<NamedDecl>(DC))
166    Visit(D);
167}
168
169void USRGenerator::VisitFieldDecl(FieldDecl *D) {
170  // The USR for an ivar declared in a class extension is based on the
171  // ObjCInterfaceDecl, not the ObjCCategoryDecl.
172  if (ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
173    Visit(ID);
174  else
175    VisitDeclContext(D->getDeclContext());
176  Out << (isa<ObjCIvarDecl>(D) ? "@" : "@FI@");
177  if (EmitDeclName(D)) {
178    // Bit fields can be anonymous.
179    IgnoreResults = true;
180    return;
181  }
182}
183
184void USRGenerator::VisitFunctionDecl(FunctionDecl *D) {
185  if (ShouldGenerateLocation(D) && GenLoc(D))
186    return;
187
188  VisitDeclContext(D->getDeclContext());
189  if (FunctionTemplateDecl *FunTmpl = D->getDescribedFunctionTemplate()) {
190    Out << "@FT@";
191    VisitTemplateParameterList(FunTmpl->getTemplateParameters());
192  } else
193    Out << "@F@";
194  D->printName(Out);
195
196  ASTContext &Ctx = *Context;
197  if (!Ctx.getLangOptions().CPlusPlus || D->isExternC())
198    return;
199
200  if (const TemplateArgumentList *
201        SpecArgs = D->getTemplateSpecializationArgs()) {
202    Out << '<';
203    for (unsigned I = 0, N = SpecArgs->size(); I != N; ++I) {
204      Out << '#';
205      VisitTemplateArgument(SpecArgs->get(I));
206    }
207    Out << '>';
208  }
209
210  // Mangle in type information for the arguments.
211  for (FunctionDecl::param_iterator I = D->param_begin(), E = D->param_end();
212       I != E; ++I) {
213    Out << '#';
214    if (ParmVarDecl *PD = *I)
215      VisitType(PD->getType());
216  }
217  if (D->isVariadic())
218    Out << '.';
219  Out << '#';
220  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
221    if (MD->isStatic())
222      Out << 'S';
223    if (unsigned quals = MD->getTypeQualifiers())
224      Out << (char)('0' + quals);
225  }
226}
227
228void USRGenerator::VisitNamedDecl(NamedDecl *D) {
229  VisitDeclContext(D->getDeclContext());
230  Out << "@";
231
232  if (EmitDeclName(D)) {
233    // The string can be empty if the declaration has no name; e.g., it is
234    // the ParmDecl with no name for declaration of a function pointer type,
235    // e.g.: void  (*f)(void *);
236    // In this case, don't generate a USR.
237    IgnoreResults = true;
238  }
239}
240
241void USRGenerator::VisitVarDecl(VarDecl *D) {
242  // VarDecls can be declared 'extern' within a function or method body,
243  // but their enclosing DeclContext is the function, not the TU.  We need
244  // to check the storage class to correctly generate the USR.
245  if (ShouldGenerateLocation(D) && GenLoc(D))
246    return;
247
248  VisitDeclContext(D->getDeclContext());
249
250  // Variables always have simple names.
251  StringRef s = D->getName();
252
253  // The string can be empty if the declaration has no name; e.g., it is
254  // the ParmDecl with no name for declaration of a function pointer type, e.g.:
255  //    void  (*f)(void *);
256  // In this case, don't generate a USR.
257  if (s.empty())
258    IgnoreResults = true;
259  else
260    Out << '@' << s;
261}
262
263void USRGenerator::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
264  GenLoc(D);
265  return;
266}
267
268void USRGenerator::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
269  GenLoc(D);
270  return;
271}
272
273void USRGenerator::VisitNamespaceDecl(NamespaceDecl *D) {
274  if (D->isAnonymousNamespace()) {
275    Out << "@aN";
276    return;
277  }
278
279  VisitDeclContext(D->getDeclContext());
280  if (!IgnoreResults)
281    Out << "@N@" << D->getName();
282}
283
284void USRGenerator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
285  VisitFunctionDecl(D->getTemplatedDecl());
286}
287
288void USRGenerator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
289  VisitTagDecl(D->getTemplatedDecl());
290}
291
292void USRGenerator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
293  VisitDeclContext(D->getDeclContext());
294  if (!IgnoreResults)
295    Out << "@NA@" << D->getName();
296}
297
298void USRGenerator::VisitObjCMethodDecl(ObjCMethodDecl *D) {
299  DeclContext *container = D->getDeclContext();
300  if (ObjCProtocolDecl *pd = dyn_cast<ObjCProtocolDecl>(container)) {
301    Visit(pd);
302  }
303  else {
304    // The USR for a method declared in a class extension or category is based on
305    // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
306    ObjCInterfaceDecl *ID = D->getClassInterface();
307    if (!ID) {
308      IgnoreResults = true;
309      return;
310    }
311    Visit(ID);
312  }
313  // Ideally we would use 'GenObjCMethod', but this is such a hot path
314  // for Objective-C code that we don't want to use
315  // DeclarationName::getAsString().
316  Out << (D->isInstanceMethod() ? "(im)" : "(cm)");
317  DeclarationName N(D->getSelector());
318  N.printName(Out);
319}
320
321void USRGenerator::VisitObjCContainerDecl(ObjCContainerDecl *D) {
322  switch (D->getKind()) {
323    default:
324      llvm_unreachable("Invalid ObjC container.");
325    case Decl::ObjCInterface:
326    case Decl::ObjCImplementation:
327      GenObjCClass(D->getName());
328      break;
329    case Decl::ObjCCategory: {
330      ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D);
331      ObjCInterfaceDecl *ID = CD->getClassInterface();
332      if (!ID) {
333        // Handle invalid code where the @interface might not
334        // have been specified.
335        // FIXME: We should be able to generate this USR even if the
336        // @interface isn't available.
337        IgnoreResults = true;
338        return;
339      }
340      // Specially handle class extensions, which are anonymous categories.
341      // We want to mangle in the location to uniquely distinguish them.
342      if (CD->IsClassExtension()) {
343        Out << "objc(ext)" << ID->getName() << '@';
344        GenLoc(CD);
345      }
346      else
347        GenObjCCategory(ID->getName(), CD->getName());
348
349      break;
350    }
351    case Decl::ObjCCategoryImpl: {
352      ObjCCategoryImplDecl *CD = cast<ObjCCategoryImplDecl>(D);
353      ObjCInterfaceDecl *ID = CD->getClassInterface();
354      if (!ID) {
355        // Handle invalid code where the @interface might not
356        // have been specified.
357        // FIXME: We should be able to generate this USR even if the
358        // @interface isn't available.
359        IgnoreResults = true;
360        return;
361      }
362      GenObjCCategory(ID->getName(), CD->getName());
363      break;
364    }
365    case Decl::ObjCProtocol:
366      GenObjCProtocol(cast<ObjCProtocolDecl>(D)->getName());
367      break;
368  }
369}
370
371void USRGenerator::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
372  // The USR for a property declared in a class extension or category is based
373  // on the ObjCInterfaceDecl, not the ObjCCategoryDecl.
374  if (ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
375    Visit(ID);
376  else
377    Visit(cast<Decl>(D->getDeclContext()));
378  GenObjCProperty(D->getName());
379}
380
381void USRGenerator::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
382  if (ObjCPropertyDecl *PD = D->getPropertyDecl()) {
383    VisitObjCPropertyDecl(PD);
384    return;
385  }
386
387  IgnoreResults = true;
388}
389
390void USRGenerator::VisitTagDecl(TagDecl *D) {
391  // Add the location of the tag decl to handle resolution across
392  // translation units.
393  if (ShouldGenerateLocation(D) && GenLoc(D))
394    return;
395
396  D = D->getCanonicalDecl();
397  VisitDeclContext(D->getDeclContext());
398
399  bool AlreadyStarted = false;
400  if (CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(D)) {
401    if (ClassTemplateDecl *ClassTmpl = CXXRecord->getDescribedClassTemplate()) {
402      AlreadyStarted = true;
403
404      switch (D->getTagKind()) {
405      case TTK_Struct: Out << "@ST"; break;
406      case TTK_Class:  Out << "@CT"; break;
407      case TTK_Union:  Out << "@UT"; break;
408      case TTK_Enum: llvm_unreachable("enum template");
409      }
410      VisitTemplateParameterList(ClassTmpl->getTemplateParameters());
411    } else if (ClassTemplatePartialSpecializationDecl *PartialSpec
412                = dyn_cast<ClassTemplatePartialSpecializationDecl>(CXXRecord)) {
413      AlreadyStarted = true;
414
415      switch (D->getTagKind()) {
416      case TTK_Struct: Out << "@SP"; break;
417      case TTK_Class:  Out << "@CP"; break;
418      case TTK_Union:  Out << "@UP"; break;
419      case TTK_Enum: llvm_unreachable("enum partial specialization");
420      }
421      VisitTemplateParameterList(PartialSpec->getTemplateParameters());
422    }
423  }
424
425  if (!AlreadyStarted) {
426    switch (D->getTagKind()) {
427      case TTK_Struct: Out << "@S"; break;
428      case TTK_Class:  Out << "@C"; break;
429      case TTK_Union:  Out << "@U"; break;
430      case TTK_Enum:   Out << "@E"; break;
431    }
432  }
433
434  Out << '@';
435  Out.flush();
436  assert(Buf.size() > 0);
437  const unsigned off = Buf.size() - 1;
438
439  if (EmitDeclName(D)) {
440    if (const TypedefNameDecl *TD = D->getTypedefNameForAnonDecl()) {
441      Buf[off] = 'A';
442      Out << '@' << *TD;
443    }
444    else
445      Buf[off] = 'a';
446  }
447
448  // For a class template specialization, mangle the template arguments.
449  if (ClassTemplateSpecializationDecl *Spec
450                              = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
451    const TemplateArgumentList &Args = Spec->getTemplateInstantiationArgs();
452    Out << '>';
453    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
454      Out << '#';
455      VisitTemplateArgument(Args.get(I));
456    }
457  }
458}
459
460void USRGenerator::VisitTypedefDecl(TypedefDecl *D) {
461  if (ShouldGenerateLocation(D) && GenLoc(D))
462    return;
463  DeclContext *DC = D->getDeclContext();
464  if (NamedDecl *DCN = dyn_cast<NamedDecl>(DC))
465    Visit(DCN);
466  Out << "@T@";
467  Out << D->getName();
468}
469
470void USRGenerator::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
471  GenLoc(D);
472  return;
473}
474
475bool USRGenerator::GenLoc(const Decl *D) {
476  if (generatedLoc)
477    return IgnoreResults;
478  generatedLoc = true;
479
480  // Guard against null declarations in invalid code.
481  if (!D) {
482    IgnoreResults = true;
483    return true;
484  }
485
486  // Use the location of canonical decl.
487  D = D->getCanonicalDecl();
488
489  const SourceManager &SM = Context->getSourceManager();
490  SourceLocation L = D->getLocStart();
491  if (L.isInvalid()) {
492    IgnoreResults = true;
493    return true;
494  }
495  L = SM.getExpansionLoc(L);
496  const std::pair<FileID, unsigned> &Decomposed = SM.getDecomposedLoc(L);
497  const FileEntry *FE = SM.getFileEntryForID(Decomposed.first);
498  if (FE) {
499    Out << llvm::sys::path::filename(FE->getName());
500  }
501  else {
502    // This case really isn't interesting.
503    IgnoreResults = true;
504    return true;
505  }
506  // Use the offest into the FileID to represent the location.  Using
507  // a line/column can cause us to look back at the original source file,
508  // which is expensive.
509  Out << '@' << Decomposed.second;
510  return IgnoreResults;
511}
512
513void USRGenerator::VisitType(QualType T) {
514  // This method mangles in USR information for types.  It can possibly
515  // just reuse the naming-mangling logic used by codegen, although the
516  // requirements for USRs might not be the same.
517  ASTContext &Ctx = *Context;
518
519  do {
520    T = Ctx.getCanonicalType(T);
521    Qualifiers Q = T.getQualifiers();
522    unsigned qVal = 0;
523    if (Q.hasConst())
524      qVal |= 0x1;
525    if (Q.hasVolatile())
526      qVal |= 0x2;
527    if (Q.hasRestrict())
528      qVal |= 0x4;
529    if(qVal)
530      Out << ((char) ('0' + qVal));
531
532    // Mangle in ObjC GC qualifiers?
533
534    if (const PackExpansionType *Expansion = T->getAs<PackExpansionType>()) {
535      Out << 'P';
536      T = Expansion->getPattern();
537    }
538
539    if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
540      unsigned char c = '\0';
541      switch (BT->getKind()) {
542        case BuiltinType::Void:
543          c = 'v'; break;
544        case BuiltinType::Bool:
545          c = 'b'; break;
546        case BuiltinType::Char_U:
547        case BuiltinType::UChar:
548          c = 'c'; break;
549        case BuiltinType::Char16:
550          c = 'q'; break;
551        case BuiltinType::Char32:
552          c = 'w'; break;
553        case BuiltinType::UShort:
554          c = 's'; break;
555        case BuiltinType::UInt:
556          c = 'i'; break;
557        case BuiltinType::ULong:
558          c = 'l'; break;
559        case BuiltinType::ULongLong:
560          c = 'k'; break;
561        case BuiltinType::UInt128:
562          c = 'j'; break;
563        case BuiltinType::Char_S:
564        case BuiltinType::SChar:
565          c = 'C'; break;
566        case BuiltinType::WChar_S:
567        case BuiltinType::WChar_U:
568          c = 'W'; break;
569        case BuiltinType::Short:
570          c = 'S'; break;
571        case BuiltinType::Int:
572          c = 'I'; break;
573        case BuiltinType::Long:
574          c = 'L'; break;
575        case BuiltinType::LongLong:
576          c = 'K'; break;
577        case BuiltinType::Int128:
578          c = 'J'; break;
579        case BuiltinType::Half:
580          c = 'h'; break;
581        case BuiltinType::Float:
582          c = 'f'; break;
583        case BuiltinType::Double:
584          c = 'd'; break;
585        case BuiltinType::LongDouble:
586          c = 'D'; break;
587        case BuiltinType::NullPtr:
588          c = 'n'; break;
589#define BUILTIN_TYPE(Id, SingletonId)
590#define PLACEHOLDER_TYPE(Id, SingletonId) case BuiltinType::Id:
591#include "clang/AST/BuiltinTypes.def"
592        case BuiltinType::Dependent:
593          IgnoreResults = true;
594          return;
595        case BuiltinType::ObjCId:
596          c = 'o'; break;
597        case BuiltinType::ObjCClass:
598          c = 'O'; break;
599        case BuiltinType::ObjCSel:
600          c = 'e'; break;
601      }
602      Out << c;
603      return;
604    }
605
606    // If we have already seen this (non-built-in) type, use a substitution
607    // encoding.
608    llvm::DenseMap<const Type *, unsigned>::iterator Substitution
609      = TypeSubstitutions.find(T.getTypePtr());
610    if (Substitution != TypeSubstitutions.end()) {
611      Out << 'S' << Substitution->second << '_';
612      return;
613    } else {
614      // Record this as a substitution.
615      unsigned Number = TypeSubstitutions.size();
616      TypeSubstitutions[T.getTypePtr()] = Number;
617    }
618
619    if (const PointerType *PT = T->getAs<PointerType>()) {
620      Out << '*';
621      T = PT->getPointeeType();
622      continue;
623    }
624    if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
625      Out << '&';
626      T = RT->getPointeeType();
627      continue;
628    }
629    if (const FunctionProtoType *FT = T->getAs<FunctionProtoType>()) {
630      Out << 'F';
631      VisitType(FT->getResultType());
632      for (FunctionProtoType::arg_type_iterator
633            I = FT->arg_type_begin(), E = FT->arg_type_end(); I!=E; ++I) {
634        VisitType(*I);
635      }
636      if (FT->isVariadic())
637        Out << '.';
638      return;
639    }
640    if (const BlockPointerType *BT = T->getAs<BlockPointerType>()) {
641      Out << 'B';
642      T = BT->getPointeeType();
643      continue;
644    }
645    if (const ComplexType *CT = T->getAs<ComplexType>()) {
646      Out << '<';
647      T = CT->getElementType();
648      continue;
649    }
650    if (const TagType *TT = T->getAs<TagType>()) {
651      Out << '$';
652      VisitTagDecl(TT->getDecl());
653      return;
654    }
655    if (const TemplateTypeParmType *TTP = T->getAs<TemplateTypeParmType>()) {
656      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
657      return;
658    }
659    if (const TemplateSpecializationType *Spec
660                                    = T->getAs<TemplateSpecializationType>()) {
661      Out << '>';
662      VisitTemplateName(Spec->getTemplateName());
663      Out << Spec->getNumArgs();
664      for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
665        VisitTemplateArgument(Spec->getArg(I));
666      return;
667    }
668
669    // Unhandled type.
670    Out << ' ';
671    break;
672  } while (true);
673}
674
675void USRGenerator::VisitTemplateParameterList(
676                                         const TemplateParameterList *Params) {
677  if (!Params)
678    return;
679  Out << '>' << Params->size();
680  for (TemplateParameterList::const_iterator P = Params->begin(),
681                                          PEnd = Params->end();
682       P != PEnd; ++P) {
683    Out << '#';
684    if (isa<TemplateTypeParmDecl>(*P)) {
685      if (cast<TemplateTypeParmDecl>(*P)->isParameterPack())
686        Out<< 'p';
687      Out << 'T';
688      continue;
689    }
690
691    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
692      if (NTTP->isParameterPack())
693        Out << 'p';
694      Out << 'N';
695      VisitType(NTTP->getType());
696      continue;
697    }
698
699    TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*P);
700    if (TTP->isParameterPack())
701      Out << 'p';
702    Out << 't';
703    VisitTemplateParameterList(TTP->getTemplateParameters());
704  }
705}
706
707void USRGenerator::VisitTemplateName(TemplateName Name) {
708  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
709    if (TemplateTemplateParmDecl *TTP
710                              = dyn_cast<TemplateTemplateParmDecl>(Template)) {
711      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
712      return;
713    }
714
715    Visit(Template);
716    return;
717  }
718
719  // FIXME: Visit dependent template names.
720}
721
722void USRGenerator::VisitTemplateArgument(const TemplateArgument &Arg) {
723  switch (Arg.getKind()) {
724  case TemplateArgument::Null:
725    break;
726
727  case TemplateArgument::Declaration:
728    if (Decl *D = Arg.getAsDecl())
729      Visit(D);
730    break;
731
732  case TemplateArgument::TemplateExpansion:
733    Out << 'P'; // pack expansion of...
734    // Fall through
735  case TemplateArgument::Template:
736    VisitTemplateName(Arg.getAsTemplateOrTemplatePattern());
737    break;
738
739  case TemplateArgument::Expression:
740    // FIXME: Visit expressions.
741    break;
742
743  case TemplateArgument::Pack:
744    Out << 'p' << Arg.pack_size();
745    for (TemplateArgument::pack_iterator P = Arg.pack_begin(), PEnd = Arg.pack_end();
746         P != PEnd; ++P)
747      VisitTemplateArgument(*P);
748    break;
749
750  case TemplateArgument::Type:
751    VisitType(Arg.getAsType());
752    break;
753
754  case TemplateArgument::Integral:
755    Out << 'V';
756    VisitType(Arg.getIntegralType());
757    Out << *Arg.getAsIntegral();
758    break;
759  }
760}
761
762//===----------------------------------------------------------------------===//
763// General purpose USR generation methods.
764//===----------------------------------------------------------------------===//
765
766void USRGenerator::GenObjCClass(StringRef cls) {
767  Out << "objc(cs)" << cls;
768}
769
770void USRGenerator::GenObjCCategory(StringRef cls, StringRef cat) {
771  Out << "objc(cy)" << cls << '@' << cat;
772}
773
774void USRGenerator::GenObjCIvar(StringRef ivar) {
775  Out << '@' << ivar;
776}
777
778void USRGenerator::GenObjCMethod(StringRef meth, bool isInstanceMethod) {
779  Out << (isInstanceMethod ? "(im)" : "(cm)") << meth;
780}
781
782void USRGenerator::GenObjCProperty(StringRef prop) {
783  Out << "(py)" << prop;
784}
785
786void USRGenerator::GenObjCProtocol(StringRef prot) {
787  Out << "objc(pl)" << prot;
788}
789
790//===----------------------------------------------------------------------===//
791// API hooks.
792//===----------------------------------------------------------------------===//
793
794static inline StringRef extractUSRSuffix(StringRef s) {
795  return s.startswith("c:") ? s.substr(2) : "";
796}
797
798bool cxcursor::getDeclCursorUSR(const Decl *D, SmallVectorImpl<char> &Buf) {
799  // Don't generate USRs for things with invalid locations.
800  if (!D || D->getLocStart().isInvalid())
801    return true;
802
803  // Check if the cursor has 'NoLinkage'.
804  if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
805    switch (ND->getLinkage()) {
806      case ExternalLinkage:
807        // Generate USRs for all entities with external linkage.
808        break;
809      case NoLinkage:
810      case UniqueExternalLinkage:
811        // We allow enums, typedefs, and structs that have no linkage to
812        // have USRs that are anchored to the file they were defined in
813        // (e.g., the header).  This is a little gross, but in principal
814        // enums/anonymous structs/etc. defined in a common header file
815        // are referred to across multiple translation units.
816        if (isa<TagDecl>(ND) || isa<TypedefDecl>(ND) ||
817            isa<EnumConstantDecl>(ND) || isa<FieldDecl>(ND) ||
818            isa<VarDecl>(ND) || isa<NamespaceDecl>(ND))
819          break;
820        // Fall-through.
821      case InternalLinkage:
822        if (isa<FunctionDecl>(ND))
823          break;
824    }
825
826  {
827    USRGenerator UG(&D->getASTContext(), &Buf);
828    UG->Visit(const_cast<Decl*>(D));
829
830    if (UG->ignoreResults())
831      return true;
832  }
833
834  return false;
835}
836
837extern "C" {
838
839CXString clang_getCursorUSR(CXCursor C) {
840  const CXCursorKind &K = clang_getCursorKind(C);
841
842  if (clang_isDeclaration(K)) {
843    Decl *D = cxcursor::getCursorDecl(C);
844    if (!D)
845      return createCXString("");
846
847    CXTranslationUnit TU = cxcursor::getCursorTU(C);
848    if (!TU)
849      return createCXString("");
850
851    CXStringBuf *buf = cxstring::getCXStringBuf(TU);
852    if (!buf)
853      return createCXString("");
854
855    bool Ignore = cxcursor::getDeclCursorUSR(D, buf->Data);
856    if (Ignore) {
857      disposeCXStringBuf(buf);
858      return createCXString("");
859    }
860
861    // Return the C-string, but don't make a copy since it is already in
862    // the string buffer.
863    buf->Data.push_back('\0');
864    return createCXString(buf);
865  }
866
867  if (K == CXCursor_MacroDefinition) {
868    CXTranslationUnit TU = cxcursor::getCursorTU(C);
869    if (!TU)
870      return createCXString("");
871
872    CXStringBuf *buf = cxstring::getCXStringBuf(TU);
873    if (!buf)
874      return createCXString("");
875
876    {
877      USRGenerator UG(&cxcursor::getCursorASTUnit(C)->getASTContext(),
878                      &buf->Data);
879      UG << "macro@"
880        << cxcursor::getCursorMacroDefinition(C)->getName()->getNameStart();
881    }
882    buf->Data.push_back('\0');
883    return createCXString(buf);
884  }
885
886  return createCXString("");
887}
888
889CXString clang_constructUSR_ObjCIvar(const char *name, CXString classUSR) {
890  USRGenerator UG;
891  UG << extractUSRSuffix(clang_getCString(classUSR));
892  UG->GenObjCIvar(name);
893  return createCXString(UG.str(), true);
894}
895
896CXString clang_constructUSR_ObjCMethod(const char *name,
897                                       unsigned isInstanceMethod,
898                                       CXString classUSR) {
899  USRGenerator UG;
900  UG << extractUSRSuffix(clang_getCString(classUSR));
901  UG->GenObjCMethod(name, isInstanceMethod);
902  return createCXString(UG.str(), true);
903}
904
905CXString clang_constructUSR_ObjCClass(const char *name) {
906  USRGenerator UG;
907  UG->GenObjCClass(name);
908  return createCXString(UG.str(), true);
909}
910
911CXString clang_constructUSR_ObjCProtocol(const char *name) {
912  USRGenerator UG;
913  UG->GenObjCProtocol(name);
914  return createCXString(UG.str(), true);
915}
916
917CXString clang_constructUSR_ObjCCategory(const char *class_name,
918                                         const char *category_name) {
919  USRGenerator UG;
920  UG->GenObjCCategory(class_name, category_name);
921  return createCXString(UG.str(), true);
922}
923
924CXString clang_constructUSR_ObjCProperty(const char *property,
925                                         CXString classUSR) {
926  USRGenerator UG;
927  UG << extractUSRSuffix(clang_getCString(classUSR));
928  UG->GenObjCProperty(property);
929  return createCXString(UG.str(), true);
930}
931
932} // end extern "C"
933