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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 
24 using namespace clang;
25 using namespace clang::cxstring;
26 
27 //===----------------------------------------------------------------------===//
28 // USR generation.
29 //===----------------------------------------------------------------------===//
30 
31 namespace {
32 class 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 
42 public:
USRGenerator(ASTContext * Ctx=0,SmallVectorImpl<char> * extBuf=0)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 
str()55   StringRef str() {
56     return Out.str();
57   }
58 
operator ->()59   USRGenerator* operator->() { return this; }
60 
61   template <typename T>
operator <<(const T & x)62   llvm::raw_svector_ostream &operator<<(const T &x) {
63     Out << x;
64     return Out;
65   }
66 
ignoreResults() const67   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);
VisitLinkageSpecDecl(LinkageSpecDecl * D)88   void VisitLinkageSpecDecl(LinkageSpecDecl *D) {
89     IgnoreResults = true;
90   }
VisitUsingDirectiveDecl(UsingDirectiveDecl * D)91   void VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
92     IgnoreResults = true;
93   }
VisitUsingDecl(UsingDecl * D)94   void VisitUsingDecl(UsingDecl *D) {
95     IgnoreResults = true;
96   }
VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl * D)97   void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
98     IgnoreResults = true;
99   }
VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl * D)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 
EmitDeclName(const NamedDecl * D)145 bool 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 
InAnonymousNamespace(const Decl * D)154 static bool InAnonymousNamespace(const Decl *D) {
155   if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(D->getDeclContext()))
156     return ND->isAnonymousNamespace();
157   return false;
158 }
159 
ShouldGenerateLocation(const NamedDecl * D)160 static inline bool ShouldGenerateLocation(const NamedDecl *D) {
161   return D->getLinkage() != ExternalLinkage && !InAnonymousNamespace(D);
162 }
163 
VisitDeclContext(DeclContext * DC)164 void USRGenerator::VisitDeclContext(DeclContext *DC) {
165   if (NamedDecl *D = dyn_cast<NamedDecl>(DC))
166     Visit(D);
167 }
168 
VisitFieldDecl(FieldDecl * D)169 void 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 
VisitFunctionDecl(FunctionDecl * D)184 void 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.getLangOpts().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 
VisitNamedDecl(NamedDecl * D)228 void 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 
VisitVarDecl(VarDecl * D)241 void 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 
VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl * D)263 void USRGenerator::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
264   GenLoc(D);
265   return;
266 }
267 
VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl * D)268 void USRGenerator::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
269   GenLoc(D);
270   return;
271 }
272 
VisitNamespaceDecl(NamespaceDecl * D)273 void 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 
VisitFunctionTemplateDecl(FunctionTemplateDecl * D)284 void USRGenerator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
285   VisitFunctionDecl(D->getTemplatedDecl());
286 }
287 
VisitClassTemplateDecl(ClassTemplateDecl * D)288 void USRGenerator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
289   VisitTagDecl(D->getTemplatedDecl());
290 }
291 
VisitNamespaceAliasDecl(NamespaceAliasDecl * D)292 void USRGenerator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
293   VisitDeclContext(D->getDeclContext());
294   if (!IgnoreResults)
295     Out << "@NA@" << D->getName();
296 }
297 
VisitObjCMethodDecl(ObjCMethodDecl * D)298 void 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 
VisitObjCContainerDecl(ObjCContainerDecl * D)321 void 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 
VisitObjCPropertyDecl(ObjCPropertyDecl * D)371 void 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 
VisitObjCPropertyImplDecl(ObjCPropertyImplDecl * D)381 void USRGenerator::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
382   if (ObjCPropertyDecl *PD = D->getPropertyDecl()) {
383     VisitObjCPropertyDecl(PD);
384     return;
385   }
386 
387   IgnoreResults = true;
388 }
389 
VisitTagDecl(TagDecl * D)390 void 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 
VisitTypedefDecl(TypedefDecl * D)460 void 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 
VisitTemplateTypeParmDecl(TemplateTypeParmDecl * D)470 void USRGenerator::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
471   GenLoc(D);
472   return;
473 }
474 
GenLoc(const Decl * D)475 bool 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 
VisitType(QualType T)513 void 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 
VisitTemplateParameterList(const TemplateParameterList * Params)675 void 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 
VisitTemplateName(TemplateName Name)707 void 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 
VisitTemplateArgument(const TemplateArgument & Arg)722 void 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 
GenObjCClass(StringRef cls)766 void USRGenerator::GenObjCClass(StringRef cls) {
767   Out << "objc(cs)" << cls;
768 }
769 
GenObjCCategory(StringRef cls,StringRef cat)770 void USRGenerator::GenObjCCategory(StringRef cls, StringRef cat) {
771   Out << "objc(cy)" << cls << '@' << cat;
772 }
773 
GenObjCIvar(StringRef ivar)774 void USRGenerator::GenObjCIvar(StringRef ivar) {
775   Out << '@' << ivar;
776 }
777 
GenObjCMethod(StringRef meth,bool isInstanceMethod)778 void USRGenerator::GenObjCMethod(StringRef meth, bool isInstanceMethod) {
779   Out << (isInstanceMethod ? "(im)" : "(cm)") << meth;
780 }
781 
GenObjCProperty(StringRef prop)782 void USRGenerator::GenObjCProperty(StringRef prop) {
783   Out << "(py)" << prop;
784 }
785 
GenObjCProtocol(StringRef prot)786 void USRGenerator::GenObjCProtocol(StringRef prot) {
787   Out << "objc(pl)" << prot;
788 }
789 
790 //===----------------------------------------------------------------------===//
791 // API hooks.
792 //===----------------------------------------------------------------------===//
793 
extractUSRSuffix(StringRef s)794 static inline StringRef extractUSRSuffix(StringRef s) {
795   return s.startswith("c:") ? s.substr(2) : "";
796 }
797 
getDeclCursorUSR(const Decl * D,SmallVectorImpl<char> & Buf)798 bool 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 
837 extern "C" {
838 
clang_getCursorUSR(CXCursor C)839 CXString 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 
clang_constructUSR_ObjCIvar(const char * name,CXString classUSR)889 CXString 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 
clang_constructUSR_ObjCMethod(const char * name,unsigned isInstanceMethod,CXString classUSR)896 CXString 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 
clang_constructUSR_ObjCClass(const char * name)905 CXString clang_constructUSR_ObjCClass(const char *name) {
906   USRGenerator UG;
907   UG->GenObjCClass(name);
908   return createCXString(UG.str(), true);
909 }
910 
clang_constructUSR_ObjCProtocol(const char * name)911 CXString clang_constructUSR_ObjCProtocol(const char *name) {
912   USRGenerator UG;
913   UG->GenObjCProtocol(name);
914   return createCXString(UG.str(), true);
915 }
916 
clang_constructUSR_ObjCCategory(const char * class_name,const char * category_name)917 CXString 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 
clang_constructUSR_ObjCProperty(const char * property,CXString classUSR)924 CXString 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