1 //===--- Registry.cpp - Matcher registry -------------------------===//
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 /// \file
11 /// \brief Registry map populated at static initialization time.
12 ///
13 //===------------------------------------------------------------===//
14 
15 #include "clang/ASTMatchers/Dynamic/Registry.h"
16 #include "Marshallers.h"
17 #include "clang/ASTMatchers/ASTMatchers.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/Support/ManagedStatic.h"
22 #include <set>
23 #include <utility>
24 
25 using namespace clang::ast_type_traits;
26 
27 namespace clang {
28 namespace ast_matchers {
29 namespace dynamic {
30 namespace {
31 
32 using internal::MatcherDescriptor;
33 
34 typedef llvm::StringMap<const MatcherDescriptor *> ConstructorMap;
35 class RegistryMaps {
36 public:
37   RegistryMaps();
38   ~RegistryMaps();
39 
40   const ConstructorMap &constructors() const { return Constructors; }
41 
42 private:
43   void registerMatcher(StringRef MatcherName, MatcherDescriptor *Callback);
44   ConstructorMap Constructors;
45 };
46 
47 void RegistryMaps::registerMatcher(StringRef MatcherName,
48                                    MatcherDescriptor *Callback) {
49   assert(Constructors.find(MatcherName) == Constructors.end());
50   Constructors[MatcherName] = Callback;
51 }
52 
53 #define REGISTER_MATCHER(name)                                                 \
54   registerMatcher(#name, internal::makeMatcherAutoMarshall(                    \
55                              ::clang::ast_matchers::name, #name));
56 
57 #define SPECIFIC_MATCHER_OVERLOAD(name, Id)                                    \
58   static_cast< ::clang::ast_matchers::name##_Type##Id>(                        \
59       ::clang::ast_matchers::name)
60 
61 #define REGISTER_OVERLOADED_2(name)                                            \
62   do {                                                                         \
63     MatcherDescriptor *Callbacks[] = {                                         \
64       internal::makeMatcherAutoMarshall(SPECIFIC_MATCHER_OVERLOAD(name, 0),    \
65                                         #name),                                \
66       internal::makeMatcherAutoMarshall(SPECIFIC_MATCHER_OVERLOAD(name, 1),    \
67                                         #name)                                 \
68     };                                                                         \
69     registerMatcher(#name,                                                     \
70                     new internal::OverloadedMatcherDescriptor(Callbacks));     \
71   } while (0)
72 
73 /// \brief Generate a registry map with all the known matchers.
74 RegistryMaps::RegistryMaps() {
75   // TODO: Here is the list of the missing matchers, grouped by reason.
76   //
77   // Need Variant/Parser fixes:
78   // ofKind
79   //
80   // Polymorphic + argument overload:
81   // findAll
82   //
83   // Other:
84   // equals
85   // equalsNode
86 
87   REGISTER_OVERLOADED_2(callee);
88   REGISTER_OVERLOADED_2(hasPrefix);
89   REGISTER_OVERLOADED_2(hasType);
90   REGISTER_OVERLOADED_2(isDerivedFrom);
91   REGISTER_OVERLOADED_2(isSameOrDerivedFrom);
92   REGISTER_OVERLOADED_2(loc);
93   REGISTER_OVERLOADED_2(pointsTo);
94   REGISTER_OVERLOADED_2(references);
95   REGISTER_OVERLOADED_2(thisPointerType);
96 
97   REGISTER_MATCHER(accessSpecDecl);
98   REGISTER_MATCHER(alignOfExpr);
99   REGISTER_MATCHER(allOf);
100   REGISTER_MATCHER(anyOf);
101   REGISTER_MATCHER(anything);
102   REGISTER_MATCHER(argumentCountIs);
103   REGISTER_MATCHER(arraySubscriptExpr);
104   REGISTER_MATCHER(arrayType);
105   REGISTER_MATCHER(asmStmt);
106   REGISTER_MATCHER(asString);
107   REGISTER_MATCHER(atomicType);
108   REGISTER_MATCHER(autoType);
109   REGISTER_MATCHER(binaryOperator);
110   REGISTER_MATCHER(bindTemporaryExpr);
111   REGISTER_MATCHER(blockPointerType);
112   REGISTER_MATCHER(boolLiteral);
113   REGISTER_MATCHER(breakStmt);
114   REGISTER_MATCHER(builtinType);
115   REGISTER_MATCHER(callExpr);
116   REGISTER_MATCHER(caseStmt);
117   REGISTER_MATCHER(castExpr);
118   REGISTER_MATCHER(catchStmt);
119   REGISTER_MATCHER(characterLiteral);
120   REGISTER_MATCHER(classTemplateDecl);
121   REGISTER_MATCHER(classTemplateSpecializationDecl);
122   REGISTER_MATCHER(complexType);
123   REGISTER_MATCHER(compoundLiteralExpr);
124   REGISTER_MATCHER(compoundStmt);
125   REGISTER_MATCHER(conditionalOperator);
126   REGISTER_MATCHER(constantArrayType);
127   REGISTER_MATCHER(constCastExpr);
128   REGISTER_MATCHER(constructExpr);
129   REGISTER_MATCHER(constructorDecl);
130   REGISTER_MATCHER(containsDeclaration);
131   REGISTER_MATCHER(continueStmt);
132   REGISTER_MATCHER(conversionDecl);
133   REGISTER_MATCHER(cStyleCastExpr);
134   REGISTER_MATCHER(ctorInitializer);
135   REGISTER_MATCHER(CUDAKernelCallExpr);
136   REGISTER_MATCHER(decl);
137   REGISTER_MATCHER(declaratorDecl);
138   REGISTER_MATCHER(declCountIs);
139   REGISTER_MATCHER(declRefExpr);
140   REGISTER_MATCHER(declStmt);
141   REGISTER_MATCHER(defaultArgExpr);
142   REGISTER_MATCHER(defaultStmt);
143   REGISTER_MATCHER(deleteExpr);
144   REGISTER_MATCHER(dependentSizedArrayType);
145   REGISTER_MATCHER(destructorDecl);
146   REGISTER_MATCHER(doStmt);
147   REGISTER_MATCHER(dynamicCastExpr);
148   REGISTER_MATCHER(eachOf);
149   REGISTER_MATCHER(elaboratedType);
150   REGISTER_MATCHER(enumConstantDecl);
151   REGISTER_MATCHER(enumDecl);
152   REGISTER_MATCHER(equalsBoundNode);
153   REGISTER_MATCHER(equalsIntegralValue);
154   REGISTER_MATCHER(explicitCastExpr);
155   REGISTER_MATCHER(expr);
156   REGISTER_MATCHER(exprWithCleanups);
157   REGISTER_MATCHER(fieldDecl);
158   REGISTER_MATCHER(floatLiteral);
159   REGISTER_MATCHER(forEach);
160   REGISTER_MATCHER(forEachConstructorInitializer);
161   REGISTER_MATCHER(forEachDescendant);
162   REGISTER_MATCHER(forEachSwitchCase);
163   REGISTER_MATCHER(forField);
164   REGISTER_MATCHER(forRangeStmt);
165   REGISTER_MATCHER(forStmt);
166   REGISTER_MATCHER(friendDecl);
167   REGISTER_MATCHER(functionalCastExpr);
168   REGISTER_MATCHER(functionDecl);
169   REGISTER_MATCHER(functionTemplateDecl);
170   REGISTER_MATCHER(functionType);
171   REGISTER_MATCHER(gotoStmt);
172   REGISTER_MATCHER(has);
173   REGISTER_MATCHER(hasAncestor);
174   REGISTER_MATCHER(hasAnyArgument);
175   REGISTER_MATCHER(hasAnyConstructorInitializer);
176   REGISTER_MATCHER(hasAnyParameter);
177   REGISTER_MATCHER(hasAnySubstatement);
178   REGISTER_MATCHER(hasAnyTemplateArgument);
179   REGISTER_MATCHER(hasAnyUsingShadowDecl);
180   REGISTER_MATCHER(hasArgument);
181   REGISTER_MATCHER(hasArgumentOfType);
182   REGISTER_MATCHER(hasAttr);
183   REGISTER_MATCHER(hasBase);
184   REGISTER_MATCHER(hasBody);
185   REGISTER_MATCHER(hasCanonicalType);
186   REGISTER_MATCHER(hasCaseConstant);
187   REGISTER_MATCHER(hasCondition);
188   REGISTER_MATCHER(hasConditionVariableStatement);
189   REGISTER_MATCHER(hasDeclaration);
190   REGISTER_MATCHER(hasDeclContext);
191   REGISTER_MATCHER(hasDeducedType);
192   REGISTER_MATCHER(hasDescendant);
193   REGISTER_MATCHER(hasDestinationType);
194   REGISTER_MATCHER(hasEitherOperand);
195   REGISTER_MATCHER(hasElementType);
196   REGISTER_MATCHER(hasElse);
197   REGISTER_MATCHER(hasFalseExpression);
198   REGISTER_MATCHER(hasGlobalStorage);
199   REGISTER_MATCHER(hasImplicitDestinationType);
200   REGISTER_MATCHER(hasIncrement);
201   REGISTER_MATCHER(hasIndex);
202   REGISTER_MATCHER(hasInitializer);
203   REGISTER_MATCHER(hasKeywordSelector);
204   REGISTER_MATCHER(hasLHS);
205   REGISTER_MATCHER(hasLocalQualifiers);
206   REGISTER_MATCHER(hasLocalStorage);
207   REGISTER_MATCHER(hasLoopInit);
208   REGISTER_MATCHER(hasLoopVariable);
209   REGISTER_MATCHER(hasMethod);
210   REGISTER_MATCHER(hasName);
211   REGISTER_MATCHER(hasNullSelector);
212   REGISTER_MATCHER(hasObjectExpression);
213   REGISTER_MATCHER(hasOperatorName);
214   REGISTER_MATCHER(hasOverloadedOperatorName);
215   REGISTER_MATCHER(hasParameter);
216   REGISTER_MATCHER(hasParent);
217   REGISTER_MATCHER(hasQualifier);
218   REGISTER_MATCHER(hasRangeInit);
219   REGISTER_MATCHER(hasReceiverType);
220   REGISTER_MATCHER(hasRHS);
221   REGISTER_MATCHER(hasSelector);
222   REGISTER_MATCHER(hasSingleDecl);
223   REGISTER_MATCHER(hasSize);
224   REGISTER_MATCHER(hasSizeExpr);
225   REGISTER_MATCHER(hasSourceExpression);
226   REGISTER_MATCHER(hasTargetDecl);
227   REGISTER_MATCHER(hasTemplateArgument);
228   REGISTER_MATCHER(hasThen);
229   REGISTER_MATCHER(hasTrueExpression);
230   REGISTER_MATCHER(hasTypeLoc);
231   REGISTER_MATCHER(hasUnaryOperand);
232   REGISTER_MATCHER(hasUnarySelector);
233   REGISTER_MATCHER(hasValueType);
234   REGISTER_MATCHER(ifStmt);
235   REGISTER_MATCHER(ignoringImpCasts);
236   REGISTER_MATCHER(ignoringParenCasts);
237   REGISTER_MATCHER(ignoringParenImpCasts);
238   REGISTER_MATCHER(implicitCastExpr);
239   REGISTER_MATCHER(incompleteArrayType);
240   REGISTER_MATCHER(initListExpr);
241   REGISTER_MATCHER(innerType);
242   REGISTER_MATCHER(integerLiteral);
243   REGISTER_MATCHER(isAnonymous);
244   REGISTER_MATCHER(isArrow);
245   REGISTER_MATCHER(isBaseInitializer);
246   REGISTER_MATCHER(isCatchAll);
247   REGISTER_MATCHER(isConst);
248   REGISTER_MATCHER(isConstQualified);
249   REGISTER_MATCHER(isCopyConstructor);
250   REGISTER_MATCHER(isDefaultConstructor);
251   REGISTER_MATCHER(isDefinition);
252   REGISTER_MATCHER(isDeleted);
253   REGISTER_MATCHER(isExceptionVariable);
254   REGISTER_MATCHER(isExplicit);
255   REGISTER_MATCHER(isExplicitTemplateSpecialization);
256   REGISTER_MATCHER(isExpr);
257   REGISTER_MATCHER(isExternC);
258   REGISTER_MATCHER(isFinal);
259   REGISTER_MATCHER(isInline);
260   REGISTER_MATCHER(isImplicit);
261   REGISTER_MATCHER(isExpansionInFileMatching);
262   REGISTER_MATCHER(isExpansionInMainFile);
263   REGISTER_MATCHER(isInstantiated);
264   REGISTER_MATCHER(isExpansionInSystemHeader);
265   REGISTER_MATCHER(isInteger);
266   REGISTER_MATCHER(isIntegral);
267   REGISTER_MATCHER(isInTemplateInstantiation);
268   REGISTER_MATCHER(isListInitialization);
269   REGISTER_MATCHER(isMemberInitializer);
270   REGISTER_MATCHER(isMoveConstructor);
271   REGISTER_MATCHER(isOverride);
272   REGISTER_MATCHER(isPrivate);
273   REGISTER_MATCHER(isProtected);
274   REGISTER_MATCHER(isPublic);
275   REGISTER_MATCHER(isPure);
276   REGISTER_MATCHER(isTemplateInstantiation);
277   REGISTER_MATCHER(isVirtual);
278   REGISTER_MATCHER(isWritten);
279   REGISTER_MATCHER(labelStmt);
280   REGISTER_MATCHER(lambdaExpr);
281   REGISTER_MATCHER(lValueReferenceType);
282   REGISTER_MATCHER(matchesName);
283   REGISTER_MATCHER(matchesSelector);
284   REGISTER_MATCHER(materializeTemporaryExpr);
285   REGISTER_MATCHER(member);
286   REGISTER_MATCHER(memberCallExpr);
287   REGISTER_MATCHER(memberExpr);
288   REGISTER_MATCHER(memberPointerType);
289   REGISTER_MATCHER(methodDecl);
290   REGISTER_MATCHER(namedDecl);
291   REGISTER_MATCHER(namespaceDecl);
292   REGISTER_MATCHER(namesType);
293   REGISTER_MATCHER(nestedNameSpecifier);
294   REGISTER_MATCHER(nestedNameSpecifierLoc);
295   REGISTER_MATCHER(newExpr);
296   REGISTER_MATCHER(nullPtrLiteralExpr);
297   REGISTER_MATCHER(nullStmt);
298   REGISTER_MATCHER(numSelectorArgs);
299   REGISTER_MATCHER(ofClass);
300   REGISTER_MATCHER(objcMessageExpr);
301   REGISTER_MATCHER(on);
302   REGISTER_MATCHER(onImplicitObjectArgument);
303   REGISTER_MATCHER(operatorCallExpr);
304   REGISTER_MATCHER(parameterCountIs);
305   REGISTER_MATCHER(parenType);
306   REGISTER_MATCHER(parmVarDecl);
307   REGISTER_MATCHER(pointee);
308   REGISTER_MATCHER(pointerType);
309   REGISTER_MATCHER(qualType);
310   REGISTER_MATCHER(recordDecl);
311   REGISTER_MATCHER(recordType);
312   REGISTER_MATCHER(referenceType);
313   REGISTER_MATCHER(refersToDeclaration);
314   REGISTER_MATCHER(refersToIntegralType);
315   REGISTER_MATCHER(refersToType);
316   REGISTER_MATCHER(reinterpretCastExpr);
317   REGISTER_MATCHER(returns);
318   REGISTER_MATCHER(returnStmt);
319   REGISTER_MATCHER(rValueReferenceType);
320   REGISTER_MATCHER(sizeOfExpr);
321   REGISTER_MATCHER(specifiesNamespace);
322   REGISTER_MATCHER(specifiesType);
323   REGISTER_MATCHER(specifiesTypeLoc);
324   REGISTER_MATCHER(statementCountIs);
325   REGISTER_MATCHER(staticCastExpr);
326   REGISTER_MATCHER(staticAssertDecl);
327   REGISTER_MATCHER(stmt);
328   REGISTER_MATCHER(stringLiteral);
329   REGISTER_MATCHER(substNonTypeTemplateParmExpr);
330   REGISTER_MATCHER(switchCase);
331   REGISTER_MATCHER(switchStmt);
332   REGISTER_MATCHER(templateArgument);
333   REGISTER_MATCHER(templateArgumentCountIs);
334   REGISTER_MATCHER(templateSpecializationType);
335   REGISTER_MATCHER(temporaryObjectExpr);
336   REGISTER_MATCHER(thisExpr);
337   REGISTER_MATCHER(throughUsingDecl);
338   REGISTER_MATCHER(throwExpr);
339   REGISTER_MATCHER(to);
340   REGISTER_MATCHER(translationUnitDecl);
341   REGISTER_MATCHER(tryStmt);
342   REGISTER_MATCHER(type);
343   REGISTER_MATCHER(typedefDecl);
344   REGISTER_MATCHER(typedefType);
345   REGISTER_MATCHER(typeLoc);
346   REGISTER_MATCHER(unaryExprOrTypeTraitExpr);
347   REGISTER_MATCHER(unaryOperator);
348   REGISTER_MATCHER(unaryTransformType);
349   REGISTER_MATCHER(unless);
350   REGISTER_MATCHER(unresolvedConstructExpr);
351   REGISTER_MATCHER(unresolvedUsingValueDecl);
352   REGISTER_MATCHER(userDefinedLiteral);
353   REGISTER_MATCHER(usingDecl);
354   REGISTER_MATCHER(usingDirectiveDecl);
355   REGISTER_MATCHER(valueDecl);
356   REGISTER_MATCHER(varDecl);
357   REGISTER_MATCHER(variableArrayType);
358   REGISTER_MATCHER(voidType);
359   REGISTER_MATCHER(whileStmt);
360   REGISTER_MATCHER(withInitializer);
361 }
362 
363 RegistryMaps::~RegistryMaps() {
364   llvm::DeleteContainerSeconds(Constructors);
365 }
366 
367 static llvm::ManagedStatic<RegistryMaps> RegistryData;
368 
369 } // anonymous namespace
370 
371 // static
372 llvm::Optional<MatcherCtor> Registry::lookupMatcherCtor(StringRef MatcherName) {
373   ConstructorMap::const_iterator it =
374       RegistryData->constructors().find(MatcherName);
375   return it == RegistryData->constructors().end()
376              ? llvm::Optional<MatcherCtor>()
377              : it->second;
378 }
379 
380 namespace {
381 
382 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
383                               const std::set<ASTNodeKind> &KS) {
384   unsigned Count = 0;
385   for (std::set<ASTNodeKind>::const_iterator I = KS.begin(), E = KS.end();
386        I != E; ++I) {
387     if (I != KS.begin())
388       OS << "|";
389     if (Count++ == 3) {
390       OS << "...";
391       break;
392     }
393     OS << *I;
394   }
395   return OS;
396 }
397 
398 }  // namespace
399 
400 std::vector<ArgKind> Registry::getAcceptedCompletionTypes(
401     ArrayRef<std::pair<MatcherCtor, unsigned>> Context) {
402   ASTNodeKind InitialTypes[] = {
403       ASTNodeKind::getFromNodeKind<Decl>(),
404       ASTNodeKind::getFromNodeKind<QualType>(),
405       ASTNodeKind::getFromNodeKind<Type>(),
406       ASTNodeKind::getFromNodeKind<Stmt>(),
407       ASTNodeKind::getFromNodeKind<NestedNameSpecifier>(),
408       ASTNodeKind::getFromNodeKind<NestedNameSpecifierLoc>(),
409       ASTNodeKind::getFromNodeKind<TypeLoc>()};
410 
411   // Starting with the above seed of acceptable top-level matcher types, compute
412   // the acceptable type set for the argument indicated by each context element.
413   std::set<ArgKind> TypeSet(std::begin(InitialTypes), std::end(InitialTypes));
414   for (const auto &CtxEntry : Context) {
415     MatcherCtor Ctor = CtxEntry.first;
416     unsigned ArgNumber = CtxEntry.second;
417     std::vector<ArgKind> NextTypeSet;
418     for (const ArgKind &Kind : TypeSet) {
419       if (Kind.getArgKind() == Kind.AK_Matcher &&
420           Ctor->isConvertibleTo(Kind.getMatcherKind()) &&
421           (Ctor->isVariadic() || ArgNumber < Ctor->getNumArgs()))
422         Ctor->getArgKinds(Kind.getMatcherKind(), ArgNumber, NextTypeSet);
423     }
424     TypeSet.clear();
425     TypeSet.insert(NextTypeSet.begin(), NextTypeSet.end());
426   }
427   return std::vector<ArgKind>(TypeSet.begin(), TypeSet.end());
428 }
429 
430 std::vector<MatcherCompletion>
431 Registry::getMatcherCompletions(ArrayRef<ArgKind> AcceptedTypes) {
432   std::vector<MatcherCompletion> Completions;
433 
434   // Search the registry for acceptable matchers.
435   for (const auto &M : RegistryData->constructors()) {
436     const auto *Matcher = M.getValue();
437     StringRef Name = M.getKey();
438 
439     std::set<ASTNodeKind> RetKinds;
440     unsigned NumArgs = Matcher->isVariadic() ? 1 : Matcher->getNumArgs();
441     bool IsPolymorphic = Matcher->isPolymorphic();
442     std::vector<std::vector<ArgKind>> ArgsKinds(NumArgs);
443     unsigned MaxSpecificity = 0;
444     for (const ArgKind& Kind : AcceptedTypes) {
445       if (Kind.getArgKind() != Kind.AK_Matcher)
446         continue;
447       unsigned Specificity;
448       ASTNodeKind LeastDerivedKind;
449       if (Matcher->isConvertibleTo(Kind.getMatcherKind(), &Specificity,
450                                    &LeastDerivedKind)) {
451         if (MaxSpecificity < Specificity)
452           MaxSpecificity = Specificity;
453         RetKinds.insert(LeastDerivedKind);
454         for (unsigned Arg = 0; Arg != NumArgs; ++Arg)
455           Matcher->getArgKinds(Kind.getMatcherKind(), Arg, ArgsKinds[Arg]);
456         if (IsPolymorphic)
457           break;
458       }
459     }
460 
461     if (!RetKinds.empty() && MaxSpecificity > 0) {
462       std::string Decl;
463       llvm::raw_string_ostream OS(Decl);
464 
465       if (IsPolymorphic) {
466         OS << "Matcher<T> " << Name << "(Matcher<T>";
467       } else {
468         OS << "Matcher<" << RetKinds << "> " << Name << "(";
469         for (const std::vector<ArgKind> &Arg : ArgsKinds) {
470           if (&Arg != &ArgsKinds[0])
471             OS << ", ";
472 
473           bool FirstArgKind = true;
474           std::set<ASTNodeKind> MatcherKinds;
475           // Two steps. First all non-matchers, then matchers only.
476           for (const ArgKind &AK : Arg) {
477             if (AK.getArgKind() == ArgKind::AK_Matcher) {
478               MatcherKinds.insert(AK.getMatcherKind());
479             } else {
480               if (!FirstArgKind) OS << "|";
481               FirstArgKind = false;
482               OS << AK.asString();
483             }
484           }
485           if (!MatcherKinds.empty()) {
486             if (!FirstArgKind) OS << "|";
487             OS << "Matcher<" << MatcherKinds << ">";
488           }
489         }
490       }
491       if (Matcher->isVariadic())
492         OS << "...";
493       OS << ")";
494 
495       std::string TypedText = Name;
496       TypedText += "(";
497       if (ArgsKinds.empty())
498         TypedText += ")";
499       else if (ArgsKinds[0][0].getArgKind() == ArgKind::AK_String)
500         TypedText += "\"";
501 
502       Completions.emplace_back(TypedText, OS.str(), MaxSpecificity);
503     }
504   }
505 
506   return Completions;
507 }
508 
509 // static
510 VariantMatcher Registry::constructMatcher(MatcherCtor Ctor,
511                                           const SourceRange &NameRange,
512                                           ArrayRef<ParserValue> Args,
513                                           Diagnostics *Error) {
514   return Ctor->create(NameRange, Args, Error);
515 }
516 
517 // static
518 VariantMatcher Registry::constructBoundMatcher(MatcherCtor Ctor,
519                                                const SourceRange &NameRange,
520                                                StringRef BindID,
521                                                ArrayRef<ParserValue> Args,
522                                                Diagnostics *Error) {
523   VariantMatcher Out = constructMatcher(Ctor, NameRange, Args, Error);
524   if (Out.isNull()) return Out;
525 
526   llvm::Optional<DynTypedMatcher> Result = Out.getSingleMatcher();
527   if (Result.hasValue()) {
528     llvm::Optional<DynTypedMatcher> Bound = Result->tryBind(BindID);
529     if (Bound.hasValue()) {
530       return VariantMatcher::SingleMatcher(*Bound);
531     }
532   }
533   Error->addError(NameRange, Error->ET_RegistryNotBindable);
534   return VariantMatcher();
535 }
536 
537 }  // namespace dynamic
538 }  // namespace ast_matchers
539 }  // namespace clang
540