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 "llvm/ADT/SmallString.h"
15#include "llvm/Support/Path.h"
16#include "llvm/Support/raw_ostream.h"
17
18using namespace clang;
19using namespace clang::index;
20
21//===----------------------------------------------------------------------===//
22// USR generation.
23//===----------------------------------------------------------------------===//
24
25namespace {
26class USRGenerator : public ConstDeclVisitor<USRGenerator> {
27  SmallVectorImpl<char> &Buf;
28  llvm::raw_svector_ostream Out;
29  bool IgnoreResults;
30  ASTContext *Context;
31  bool generatedLoc;
32
33  llvm::DenseMap<const Type *, unsigned> TypeSubstitutions;
34
35public:
36  explicit USRGenerator(ASTContext *Ctx, SmallVectorImpl<char> &Buf)
37  : Buf(Buf),
38    Out(Buf),
39    IgnoreResults(false),
40    Context(Ctx),
41    generatedLoc(false)
42  {
43    // Add the USR space prefix.
44    Out << getUSRSpacePrefix();
45  }
46
47  bool ignoreResults() const { return IgnoreResults; }
48
49  // Visitation methods from generating USRs from AST elements.
50  void VisitDeclContext(const DeclContext *D);
51  void VisitFieldDecl(const FieldDecl *D);
52  void VisitFunctionDecl(const FunctionDecl *D);
53  void VisitNamedDecl(const NamedDecl *D);
54  void VisitNamespaceDecl(const NamespaceDecl *D);
55  void VisitNamespaceAliasDecl(const NamespaceAliasDecl *D);
56  void VisitFunctionTemplateDecl(const FunctionTemplateDecl *D);
57  void VisitClassTemplateDecl(const ClassTemplateDecl *D);
58  void VisitObjCContainerDecl(const ObjCContainerDecl *CD);
59  void VisitObjCMethodDecl(const ObjCMethodDecl *MD);
60  void VisitObjCPropertyDecl(const ObjCPropertyDecl *D);
61  void VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D);
62  void VisitTagDecl(const TagDecl *D);
63  void VisitTypedefDecl(const TypedefDecl *D);
64  void VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *D);
65  void VisitVarDecl(const VarDecl *D);
66  void VisitNonTypeTemplateParmDecl(const NonTypeTemplateParmDecl *D);
67  void VisitTemplateTemplateParmDecl(const TemplateTemplateParmDecl *D);
68  void VisitLinkageSpecDecl(const LinkageSpecDecl *D) {
69    IgnoreResults = true;
70  }
71  void VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
72    IgnoreResults = true;
73  }
74  void VisitUsingDecl(const UsingDecl *D) {
75    IgnoreResults = true;
76  }
77  void VisitUnresolvedUsingValueDecl(const UnresolvedUsingValueDecl *D) {
78    IgnoreResults = true;
79  }
80  void VisitUnresolvedUsingTypenameDecl(const UnresolvedUsingTypenameDecl *D) {
81    IgnoreResults = true;
82  }
83
84  /// Generate the string component containing the location of the
85  ///  declaration.
86  bool GenLoc(const Decl *D);
87
88  /// String generation methods used both by the visitation methods
89  /// and from other clients that want to directly generate USRs.  These
90  /// methods do not construct complete USRs (which incorporate the parents
91  /// of an AST element), but only the fragments concerning the AST element
92  /// itself.
93
94  /// Generate a USR for an Objective-C class.
95  void GenObjCClass(StringRef cls) {
96    generateUSRForObjCClass(cls, Out);
97  }
98  /// Generate a USR for an Objective-C class category.
99  void GenObjCCategory(StringRef cls, StringRef cat) {
100    generateUSRForObjCCategory(cls, cat, Out);
101  }
102  /// Generate a USR fragment for an Objective-C instance variable.  The
103  /// complete USR can be created by concatenating the USR for the
104  /// encompassing class with this USR fragment.
105  void GenObjCIvar(StringRef ivar) {
106    generateUSRForObjCIvar(ivar, Out);
107  }
108  /// Generate a USR fragment for an Objective-C method.
109  void GenObjCMethod(StringRef sel, bool isInstanceMethod) {
110    generateUSRForObjCMethod(sel, isInstanceMethod, Out);
111  }
112  /// Generate a USR fragment for an Objective-C property.
113  void GenObjCProperty(StringRef prop) {
114    generateUSRForObjCProperty(prop, Out);
115  }
116  /// Generate a USR for an Objective-C protocol.
117  void GenObjCProtocol(StringRef prot) {
118    generateUSRForObjCProtocol(prot, Out);
119  }
120
121  void VisitType(QualType T);
122  void VisitTemplateParameterList(const TemplateParameterList *Params);
123  void VisitTemplateName(TemplateName Name);
124  void VisitTemplateArgument(const TemplateArgument &Arg);
125
126  /// Emit a Decl's name using NamedDecl::printName() and return true if
127  ///  the decl had no name.
128  bool EmitDeclName(const NamedDecl *D);
129};
130
131} // end anonymous namespace
132
133//===----------------------------------------------------------------------===//
134// Generating USRs from ASTS.
135//===----------------------------------------------------------------------===//
136
137bool USRGenerator::EmitDeclName(const NamedDecl *D) {
138  Out.flush();
139  const unsigned startSize = Buf.size();
140  D->printName(Out);
141  Out.flush();
142  const unsigned endSize = Buf.size();
143  return startSize == endSize;
144}
145
146static inline bool ShouldGenerateLocation(const NamedDecl *D) {
147  return !D->isExternallyVisible();
148}
149
150void USRGenerator::VisitDeclContext(const DeclContext *DC) {
151  if (const NamedDecl *D = dyn_cast<NamedDecl>(DC))
152    Visit(D);
153}
154
155void USRGenerator::VisitFieldDecl(const FieldDecl *D) {
156  // The USR for an ivar declared in a class extension is based on the
157  // ObjCInterfaceDecl, not the ObjCCategoryDecl.
158  if (const ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
159    Visit(ID);
160  else
161    VisitDeclContext(D->getDeclContext());
162  Out << (isa<ObjCIvarDecl>(D) ? "@" : "@FI@");
163  if (EmitDeclName(D)) {
164    // Bit fields can be anonymous.
165    IgnoreResults = true;
166    return;
167  }
168}
169
170void USRGenerator::VisitFunctionDecl(const FunctionDecl *D) {
171  if (ShouldGenerateLocation(D) && GenLoc(D))
172    return;
173
174  VisitDeclContext(D->getDeclContext());
175  if (FunctionTemplateDecl *FunTmpl = D->getDescribedFunctionTemplate()) {
176    Out << "@FT@";
177    VisitTemplateParameterList(FunTmpl->getTemplateParameters());
178  } else
179    Out << "@F@";
180  D->printName(Out);
181
182  ASTContext &Ctx = *Context;
183  if (!Ctx.getLangOpts().CPlusPlus || D->isExternC())
184    return;
185
186  if (const TemplateArgumentList *
187        SpecArgs = D->getTemplateSpecializationArgs()) {
188    Out << '<';
189    for (unsigned I = 0, N = SpecArgs->size(); I != N; ++I) {
190      Out << '#';
191      VisitTemplateArgument(SpecArgs->get(I));
192    }
193    Out << '>';
194  }
195
196  // Mangle in type information for the arguments.
197  for (FunctionDecl::param_const_iterator I = D->param_begin(),
198                                          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 (const 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(const 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(const 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  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(
251                                        const NonTypeTemplateParmDecl *D) {
252  GenLoc(D);
253  return;
254}
255
256void USRGenerator::VisitTemplateTemplateParmDecl(
257                                        const TemplateTemplateParmDecl *D) {
258  GenLoc(D);
259  return;
260}
261
262void USRGenerator::VisitNamespaceDecl(const NamespaceDecl *D) {
263  if (D->isAnonymousNamespace()) {
264    Out << "@aN";
265    return;
266  }
267
268  VisitDeclContext(D->getDeclContext());
269  if (!IgnoreResults)
270    Out << "@N@" << D->getName();
271}
272
273void USRGenerator::VisitFunctionTemplateDecl(const FunctionTemplateDecl *D) {
274  VisitFunctionDecl(D->getTemplatedDecl());
275}
276
277void USRGenerator::VisitClassTemplateDecl(const ClassTemplateDecl *D) {
278  VisitTagDecl(D->getTemplatedDecl());
279}
280
281void USRGenerator::VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
282  VisitDeclContext(D->getDeclContext());
283  if (!IgnoreResults)
284    Out << "@NA@" << D->getName();
285}
286
287void USRGenerator::VisitObjCMethodDecl(const ObjCMethodDecl *D) {
288  const DeclContext *container = D->getDeclContext();
289  if (const ObjCProtocolDecl *pd = dyn_cast<ObjCProtocolDecl>(container)) {
290    Visit(pd);
291  }
292  else {
293    // The USR for a method declared in a class extension or category is based on
294    // the ObjCInterfaceDecl, not the ObjCCategoryDecl.
295    const ObjCInterfaceDecl *ID = D->getClassInterface();
296    if (!ID) {
297      IgnoreResults = true;
298      return;
299    }
300    Visit(ID);
301  }
302  // Ideally we would use 'GenObjCMethod', but this is such a hot path
303  // for Objective-C code that we don't want to use
304  // DeclarationName::getAsString().
305  Out << (D->isInstanceMethod() ? "(im)" : "(cm)")
306      << DeclarationName(D->getSelector());
307}
308
309void USRGenerator::VisitObjCContainerDecl(const ObjCContainerDecl *D) {
310  switch (D->getKind()) {
311    default:
312      llvm_unreachable("Invalid ObjC container.");
313    case Decl::ObjCInterface:
314    case Decl::ObjCImplementation:
315      GenObjCClass(D->getName());
316      break;
317    case Decl::ObjCCategory: {
318      const ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D);
319      const ObjCInterfaceDecl *ID = CD->getClassInterface();
320      if (!ID) {
321        // Handle invalid code where the @interface might not
322        // have been specified.
323        // FIXME: We should be able to generate this USR even if the
324        // @interface isn't available.
325        IgnoreResults = true;
326        return;
327      }
328      // Specially handle class extensions, which are anonymous categories.
329      // We want to mangle in the location to uniquely distinguish them.
330      if (CD->IsClassExtension()) {
331        Out << "objc(ext)" << ID->getName() << '@';
332        GenLoc(CD);
333      }
334      else
335        GenObjCCategory(ID->getName(), CD->getName());
336
337      break;
338    }
339    case Decl::ObjCCategoryImpl: {
340      const ObjCCategoryImplDecl *CD = cast<ObjCCategoryImplDecl>(D);
341      const ObjCInterfaceDecl *ID = CD->getClassInterface();
342      if (!ID) {
343        // Handle invalid code where the @interface might not
344        // have been specified.
345        // FIXME: We should be able to generate this USR even if the
346        // @interface isn't available.
347        IgnoreResults = true;
348        return;
349      }
350      GenObjCCategory(ID->getName(), CD->getName());
351      break;
352    }
353    case Decl::ObjCProtocol:
354      GenObjCProtocol(cast<ObjCProtocolDecl>(D)->getName());
355      break;
356  }
357}
358
359void USRGenerator::VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
360  // The USR for a property declared in a class extension or category is based
361  // on the ObjCInterfaceDecl, not the ObjCCategoryDecl.
362  if (const ObjCInterfaceDecl *ID = Context->getObjContainingInterface(D))
363    Visit(ID);
364  else
365    Visit(cast<Decl>(D->getDeclContext()));
366  GenObjCProperty(D->getName());
367}
368
369void USRGenerator::VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
370  if (ObjCPropertyDecl *PD = D->getPropertyDecl()) {
371    VisitObjCPropertyDecl(PD);
372    return;
373  }
374
375  IgnoreResults = true;
376}
377
378void USRGenerator::VisitTagDecl(const TagDecl *D) {
379  // Add the location of the tag decl to handle resolution across
380  // translation units.
381  if (ShouldGenerateLocation(D) && GenLoc(D))
382    return;
383
384  D = D->getCanonicalDecl();
385  VisitDeclContext(D->getDeclContext());
386
387  bool AlreadyStarted = false;
388  if (const CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(D)) {
389    if (ClassTemplateDecl *ClassTmpl = CXXRecord->getDescribedClassTemplate()) {
390      AlreadyStarted = true;
391
392      switch (D->getTagKind()) {
393      case TTK_Interface:
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");
398      }
399      VisitTemplateParameterList(ClassTmpl->getTemplateParameters());
400    } else if (const ClassTemplatePartialSpecializationDecl *PartialSpec
401                = dyn_cast<ClassTemplatePartialSpecializationDecl>(CXXRecord)) {
402      AlreadyStarted = true;
403
404      switch (D->getTagKind()) {
405      case TTK_Interface:
406      case TTK_Struct: Out << "@SP"; break;
407      case TTK_Class:  Out << "@CP"; break;
408      case TTK_Union:  Out << "@UP"; break;
409      case TTK_Enum: llvm_unreachable("enum partial specialization");
410      }
411      VisitTemplateParameterList(PartialSpec->getTemplateParameters());
412    }
413  }
414
415  if (!AlreadyStarted) {
416    switch (D->getTagKind()) {
417      case TTK_Interface:
418      case TTK_Struct: Out << "@S"; break;
419      case TTK_Class:  Out << "@C"; break;
420      case TTK_Union:  Out << "@U"; break;
421      case TTK_Enum:   Out << "@E"; break;
422    }
423  }
424
425  Out << '@';
426  Out.flush();
427  assert(Buf.size() > 0);
428  const unsigned off = Buf.size() - 1;
429
430  if (EmitDeclName(D)) {
431    if (const TypedefNameDecl *TD = D->getTypedefNameForAnonDecl()) {
432      Buf[off] = 'A';
433      Out << '@' << *TD;
434    }
435    else
436      Buf[off] = 'a';
437  }
438
439  // For a class template specialization, mangle the template arguments.
440  if (const ClassTemplateSpecializationDecl *Spec
441                              = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
442    const TemplateArgumentList &Args = Spec->getTemplateInstantiationArgs();
443    Out << '>';
444    for (unsigned I = 0, N = Args.size(); I != N; ++I) {
445      Out << '#';
446      VisitTemplateArgument(Args.get(I));
447    }
448  }
449}
450
451void USRGenerator::VisitTypedefDecl(const TypedefDecl *D) {
452  if (ShouldGenerateLocation(D) && GenLoc(D))
453    return;
454  const DeclContext *DC = D->getDeclContext();
455  if (const NamedDecl *DCN = dyn_cast<NamedDecl>(DC))
456    Visit(DCN);
457  Out << "@T@";
458  Out << D->getName();
459}
460
461void USRGenerator::VisitTemplateTypeParmDecl(const TemplateTypeParmDecl *D) {
462  GenLoc(D);
463  return;
464}
465
466bool USRGenerator::GenLoc(const Decl *D) {
467  if (generatedLoc)
468    return IgnoreResults;
469  generatedLoc = true;
470
471  // Guard against null declarations in invalid code.
472  if (!D) {
473    IgnoreResults = true;
474    return true;
475  }
476
477  // Use the location of canonical decl.
478  D = D->getCanonicalDecl();
479
480  const SourceManager &SM = Context->getSourceManager();
481  SourceLocation L = D->getLocStart();
482  if (L.isInvalid()) {
483    IgnoreResults = true;
484    return true;
485  }
486  L = SM.getExpansionLoc(L);
487  const std::pair<FileID, unsigned> &Decomposed = SM.getDecomposedLoc(L);
488  const FileEntry *FE = SM.getFileEntryForID(Decomposed.first);
489  if (FE) {
490    Out << llvm::sys::path::filename(FE->getName());
491  }
492  else {
493    // This case really isn't interesting.
494    IgnoreResults = true;
495    return true;
496  }
497  // Use the offest into the FileID to represent the location.  Using
498  // a line/column can cause us to look back at the original source file,
499  // which is expensive.
500  Out << '@' << Decomposed.second;
501  return IgnoreResults;
502}
503
504void USRGenerator::VisitType(QualType T) {
505  // This method mangles in USR information for types.  It can possibly
506  // just reuse the naming-mangling logic used by codegen, although the
507  // requirements for USRs might not be the same.
508  ASTContext &Ctx = *Context;
509
510  do {
511    T = Ctx.getCanonicalType(T);
512    Qualifiers Q = T.getQualifiers();
513    unsigned qVal = 0;
514    if (Q.hasConst())
515      qVal |= 0x1;
516    if (Q.hasVolatile())
517      qVal |= 0x2;
518    if (Q.hasRestrict())
519      qVal |= 0x4;
520    if(qVal)
521      Out << ((char) ('0' + qVal));
522
523    // Mangle in ObjC GC qualifiers?
524
525    if (const PackExpansionType *Expansion = T->getAs<PackExpansionType>()) {
526      Out << 'P';
527      T = Expansion->getPattern();
528    }
529
530    if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
531      unsigned char c = '\0';
532      switch (BT->getKind()) {
533        case BuiltinType::Void:
534          c = 'v'; break;
535        case BuiltinType::Bool:
536          c = 'b'; break;
537        case BuiltinType::Char_U:
538        case BuiltinType::UChar:
539          c = 'c'; break;
540        case BuiltinType::Char16:
541          c = 'q'; break;
542        case BuiltinType::Char32:
543          c = 'w'; break;
544        case BuiltinType::UShort:
545          c = 's'; break;
546        case BuiltinType::UInt:
547          c = 'i'; break;
548        case BuiltinType::ULong:
549          c = 'l'; break;
550        case BuiltinType::ULongLong:
551          c = 'k'; break;
552        case BuiltinType::UInt128:
553          c = 'j'; break;
554        case BuiltinType::Char_S:
555        case BuiltinType::SChar:
556          c = 'C'; break;
557        case BuiltinType::WChar_S:
558        case BuiltinType::WChar_U:
559          c = 'W'; break;
560        case BuiltinType::Short:
561          c = 'S'; break;
562        case BuiltinType::Int:
563          c = 'I'; break;
564        case BuiltinType::Long:
565          c = 'L'; break;
566        case BuiltinType::LongLong:
567          c = 'K'; break;
568        case BuiltinType::Int128:
569          c = 'J'; break;
570        case BuiltinType::Half:
571          c = 'h'; break;
572        case BuiltinType::Float:
573          c = 'f'; break;
574        case BuiltinType::Double:
575          c = 'd'; break;
576        case BuiltinType::LongDouble:
577          c = 'D'; break;
578        case BuiltinType::NullPtr:
579          c = 'n'; break;
580#define BUILTIN_TYPE(Id, SingletonId)
581#define PLACEHOLDER_TYPE(Id, SingletonId) case BuiltinType::Id:
582#include "clang/AST/BuiltinTypes.def"
583        case BuiltinType::Dependent:
584        case BuiltinType::OCLImage1d:
585        case BuiltinType::OCLImage1dArray:
586        case BuiltinType::OCLImage1dBuffer:
587        case BuiltinType::OCLImage2d:
588        case BuiltinType::OCLImage2dArray:
589        case BuiltinType::OCLImage3d:
590        case BuiltinType::OCLEvent:
591        case BuiltinType::OCLSampler:
592          IgnoreResults = true;
593          return;
594        case BuiltinType::ObjCId:
595          c = 'o'; break;
596        case BuiltinType::ObjCClass:
597          c = 'O'; break;
598        case BuiltinType::ObjCSel:
599          c = 'e'; break;
600      }
601      Out << c;
602      return;
603    }
604
605    // If we have already seen this (non-built-in) type, use a substitution
606    // encoding.
607    llvm::DenseMap<const Type *, unsigned>::iterator Substitution
608      = TypeSubstitutions.find(T.getTypePtr());
609    if (Substitution != TypeSubstitutions.end()) {
610      Out << 'S' << Substitution->second << '_';
611      return;
612    } else {
613      // Record this as a substitution.
614      unsigned Number = TypeSubstitutions.size();
615      TypeSubstitutions[T.getTypePtr()] = Number;
616    }
617
618    if (const PointerType *PT = T->getAs<PointerType>()) {
619      Out << '*';
620      T = PT->getPointeeType();
621      continue;
622    }
623    if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
624      Out << '&';
625      T = RT->getPointeeType();
626      continue;
627    }
628    if (const FunctionProtoType *FT = T->getAs<FunctionProtoType>()) {
629      Out << 'F';
630      VisitType(FT->getResultType());
631      for (FunctionProtoType::arg_type_iterator
632            I = FT->arg_type_begin(), E = FT->arg_type_end(); I!=E; ++I) {
633        VisitType(*I);
634      }
635      if (FT->isVariadic())
636        Out << '.';
637      return;
638    }
639    if (const BlockPointerType *BT = T->getAs<BlockPointerType>()) {
640      Out << 'B';
641      T = BT->getPointeeType();
642      continue;
643    }
644    if (const ComplexType *CT = T->getAs<ComplexType>()) {
645      Out << '<';
646      T = CT->getElementType();
647      continue;
648    }
649    if (const TagType *TT = T->getAs<TagType>()) {
650      Out << '$';
651      VisitTagDecl(TT->getDecl());
652      return;
653    }
654    if (const TemplateTypeParmType *TTP = T->getAs<TemplateTypeParmType>()) {
655      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
656      return;
657    }
658    if (const TemplateSpecializationType *Spec
659                                    = T->getAs<TemplateSpecializationType>()) {
660      Out << '>';
661      VisitTemplateName(Spec->getTemplateName());
662      Out << Spec->getNumArgs();
663      for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
664        VisitTemplateArgument(Spec->getArg(I));
665      return;
666    }
667
668    // Unhandled type.
669    Out << ' ';
670    break;
671  } while (true);
672}
673
674void USRGenerator::VisitTemplateParameterList(
675                                         const TemplateParameterList *Params) {
676  if (!Params)
677    return;
678  Out << '>' << Params->size();
679  for (TemplateParameterList::const_iterator P = Params->begin(),
680                                          PEnd = Params->end();
681       P != PEnd; ++P) {
682    Out << '#';
683    if (isa<TemplateTypeParmDecl>(*P)) {
684      if (cast<TemplateTypeParmDecl>(*P)->isParameterPack())
685        Out<< 'p';
686      Out << 'T';
687      continue;
688    }
689
690    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
691      if (NTTP->isParameterPack())
692        Out << 'p';
693      Out << 'N';
694      VisitType(NTTP->getType());
695      continue;
696    }
697
698    TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*P);
699    if (TTP->isParameterPack())
700      Out << 'p';
701    Out << 't';
702    VisitTemplateParameterList(TTP->getTemplateParameters());
703  }
704}
705
706void USRGenerator::VisitTemplateName(TemplateName Name) {
707  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
708    if (TemplateTemplateParmDecl *TTP
709                              = dyn_cast<TemplateTemplateParmDecl>(Template)) {
710      Out << 't' << TTP->getDepth() << '.' << TTP->getIndex();
711      return;
712    }
713
714    Visit(Template);
715    return;
716  }
717
718  // FIXME: Visit dependent template names.
719}
720
721void USRGenerator::VisitTemplateArgument(const TemplateArgument &Arg) {
722  switch (Arg.getKind()) {
723  case TemplateArgument::Null:
724    break;
725
726  case TemplateArgument::Declaration:
727    Visit(Arg.getAsDecl());
728    break;
729
730  case TemplateArgument::NullPtr:
731    break;
732
733  case TemplateArgument::TemplateExpansion:
734    Out << 'P'; // pack expansion of...
735    // Fall through
736  case TemplateArgument::Template:
737    VisitTemplateName(Arg.getAsTemplateOrTemplatePattern());
738    break;
739
740  case TemplateArgument::Expression:
741    // FIXME: Visit expressions.
742    break;
743
744  case TemplateArgument::Pack:
745    Out << 'p' << Arg.pack_size();
746    for (TemplateArgument::pack_iterator P = Arg.pack_begin(), PEnd = Arg.pack_end();
747         P != PEnd; ++P)
748      VisitTemplateArgument(*P);
749    break;
750
751  case TemplateArgument::Type:
752    VisitType(Arg.getAsType());
753    break;
754
755  case TemplateArgument::Integral:
756    Out << 'V';
757    VisitType(Arg.getIntegralType());
758    Out << Arg.getAsIntegral();
759    break;
760  }
761}
762
763//===----------------------------------------------------------------------===//
764// USR generation functions.
765//===----------------------------------------------------------------------===//
766
767void clang::index::generateUSRForObjCClass(StringRef Cls, raw_ostream &OS) {
768  OS << "objc(cs)" << Cls;
769}
770
771void clang::index::generateUSRForObjCCategory(StringRef Cls, StringRef Cat,
772                                              raw_ostream &OS) {
773  OS << "objc(cy)" << Cls << '@' << Cat;
774}
775
776void clang::index::generateUSRForObjCIvar(StringRef Ivar, raw_ostream &OS) {
777  OS << '@' << Ivar;
778}
779
780void clang::index::generateUSRForObjCMethod(StringRef Sel,
781                                            bool IsInstanceMethod,
782                                            raw_ostream &OS) {
783  OS << (IsInstanceMethod ? "(im)" : "(cm)") << Sel;
784}
785
786void clang::index::generateUSRForObjCProperty(StringRef Prop, raw_ostream &OS) {
787  OS << "(py)" << Prop;
788}
789
790void clang::index::generateUSRForObjCProtocol(StringRef Prot, raw_ostream &OS) {
791  OS << "objc(pl)" << Prot;
792}
793
794bool clang::index::generateUSRForDecl(const Decl *D,
795                                      SmallVectorImpl<char> &Buf) {
796  // Don't generate USRs for things with invalid locations.
797  if (!D || D->getLocStart().isInvalid())
798    return true;
799
800  USRGenerator UG(&D->getASTContext(), Buf);
801  UG.Visit(D);
802  return UG.ignoreResults();
803}
804