xref: /llvm-project/clang/lib/ASTMatchers/Dynamic/Registry.cpp (revision 922bef4f380c015ed370776a33a92b50c41ac04d)
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(blockPointerType);
111   REGISTER_MATCHER(booleanType);
112   REGISTER_MATCHER(breakStmt);
113   REGISTER_MATCHER(builtinType);
114   REGISTER_MATCHER(callExpr);
115   REGISTER_MATCHER(caseStmt);
116   REGISTER_MATCHER(castExpr);
117   REGISTER_MATCHER(characterLiteral);
118   REGISTER_MATCHER(classTemplateDecl);
119   REGISTER_MATCHER(classTemplateSpecializationDecl);
120   REGISTER_MATCHER(complexType);
121   REGISTER_MATCHER(compoundLiteralExpr);
122   REGISTER_MATCHER(compoundStmt);
123   REGISTER_MATCHER(conditionalOperator);
124   REGISTER_MATCHER(constantArrayType);
125   REGISTER_MATCHER(containsDeclaration);
126   REGISTER_MATCHER(continueStmt);
127   REGISTER_MATCHER(cStyleCastExpr);
128   REGISTER_MATCHER(cudaKernelCallExpr);
129   REGISTER_MATCHER(cxxBindTemporaryExpr);
130   REGISTER_MATCHER(cxxBoolLiteral);
131   REGISTER_MATCHER(cxxCatchStmt);
132   REGISTER_MATCHER(cxxConstCastExpr);
133   REGISTER_MATCHER(cxxConstructExpr);
134   REGISTER_MATCHER(cxxConstructorDecl);
135   REGISTER_MATCHER(cxxConversionDecl);
136   REGISTER_MATCHER(cxxCtorInitializer);
137   REGISTER_MATCHER(cxxDefaultArgExpr);
138   REGISTER_MATCHER(cxxDeleteExpr);
139   REGISTER_MATCHER(cxxDestructorDecl);
140   REGISTER_MATCHER(cxxDynamicCastExpr);
141   REGISTER_MATCHER(cxxForRangeStmt);
142   REGISTER_MATCHER(cxxFunctionalCastExpr);
143   REGISTER_MATCHER(cxxMemberCallExpr);
144   REGISTER_MATCHER(cxxMethodDecl);
145   REGISTER_MATCHER(cxxNewExpr);
146   REGISTER_MATCHER(cxxNullPtrLiteralExpr);
147   REGISTER_MATCHER(cxxOperatorCallExpr);
148   REGISTER_MATCHER(cxxRecordDecl);
149   REGISTER_MATCHER(cxxReinterpretCastExpr);
150   REGISTER_MATCHER(cxxStaticCastExpr);
151   REGISTER_MATCHER(cxxTemporaryObjectExpr);
152   REGISTER_MATCHER(cxxThisExpr);
153   REGISTER_MATCHER(cxxThrowExpr);
154   REGISTER_MATCHER(cxxTryStmt);
155   REGISTER_MATCHER(cxxUnresolvedConstructExpr);
156   REGISTER_MATCHER(decayedType);
157   REGISTER_MATCHER(decl);
158   REGISTER_MATCHER(declaratorDecl);
159   REGISTER_MATCHER(declCountIs);
160   REGISTER_MATCHER(declRefExpr);
161   REGISTER_MATCHER(declStmt);
162   REGISTER_MATCHER(defaultStmt);
163   REGISTER_MATCHER(dependentSizedArrayType);
164   REGISTER_MATCHER(doStmt);
165   REGISTER_MATCHER(eachOf);
166   REGISTER_MATCHER(elaboratedType);
167   REGISTER_MATCHER(enumConstantDecl);
168   REGISTER_MATCHER(enumDecl);
169   REGISTER_MATCHER(equalsBoundNode);
170   REGISTER_MATCHER(equalsIntegralValue);
171   REGISTER_MATCHER(explicitCastExpr);
172   REGISTER_MATCHER(expr);
173   REGISTER_MATCHER(exprWithCleanups);
174   REGISTER_MATCHER(fieldDecl);
175   REGISTER_MATCHER(floatLiteral);
176   REGISTER_MATCHER(forEach);
177   REGISTER_MATCHER(forEachArgumentWithParam);
178   REGISTER_MATCHER(forEachConstructorInitializer);
179   REGISTER_MATCHER(forEachDescendant);
180   REGISTER_MATCHER(forEachSwitchCase);
181   REGISTER_MATCHER(forField);
182   REGISTER_MATCHER(forStmt);
183   REGISTER_MATCHER(friendDecl);
184   REGISTER_MATCHER(functionDecl);
185   REGISTER_MATCHER(functionProtoType);
186   REGISTER_MATCHER(functionTemplateDecl);
187   REGISTER_MATCHER(functionType);
188   REGISTER_MATCHER(gnuNullExpr);
189   REGISTER_MATCHER(gotoStmt);
190   REGISTER_MATCHER(has);
191   REGISTER_MATCHER(hasAncestor);
192   REGISTER_MATCHER(hasAnyArgument);
193   REGISTER_MATCHER(hasAnyConstructorInitializer);
194   REGISTER_MATCHER(hasAnyName);
195   REGISTER_MATCHER(hasAnyParameter);
196   REGISTER_MATCHER(hasAnySubstatement);
197   REGISTER_MATCHER(hasAnyTemplateArgument);
198   REGISTER_MATCHER(hasAnyUsingShadowDecl);
199   REGISTER_MATCHER(hasArgument);
200   REGISTER_MATCHER(hasArgumentOfType);
201   REGISTER_MATCHER(hasAttr);
202   REGISTER_MATCHER(hasAutomaticStorageDuration);
203   REGISTER_MATCHER(hasBase);
204   REGISTER_MATCHER(hasBody);
205   REGISTER_MATCHER(hasCanonicalType);
206   REGISTER_MATCHER(hasCaseConstant);
207   REGISTER_MATCHER(hasCondition);
208   REGISTER_MATCHER(hasConditionVariableStatement);
209   REGISTER_MATCHER(hasDecayedType);
210   REGISTER_MATCHER(hasDeclaration);
211   REGISTER_MATCHER(hasDeclContext);
212   REGISTER_MATCHER(hasDeducedType);
213   REGISTER_MATCHER(hasDescendant);
214   REGISTER_MATCHER(hasDestinationType);
215   REGISTER_MATCHER(hasEitherOperand);
216   REGISTER_MATCHER(hasElementType);
217   REGISTER_MATCHER(hasElse);
218   REGISTER_MATCHER(hasFalseExpression);
219   REGISTER_MATCHER(hasGlobalStorage);
220   REGISTER_MATCHER(hasImplicitDestinationType);
221   REGISTER_MATCHER(hasIncrement);
222   REGISTER_MATCHER(hasIndex);
223   REGISTER_MATCHER(hasInitializer);
224   REGISTER_MATCHER(hasKeywordSelector);
225   REGISTER_MATCHER(hasLHS);
226   REGISTER_MATCHER(hasLocalQualifiers);
227   REGISTER_MATCHER(hasLocalStorage);
228   REGISTER_MATCHER(hasLoopInit);
229   REGISTER_MATCHER(hasLoopVariable);
230   REGISTER_MATCHER(hasMethod);
231   REGISTER_MATCHER(hasName);
232   REGISTER_MATCHER(hasNullSelector);
233   REGISTER_MATCHER(hasObjectExpression);
234   REGISTER_MATCHER(hasOperatorName);
235   REGISTER_MATCHER(hasOverloadedOperatorName);
236   REGISTER_MATCHER(hasParameter);
237   REGISTER_MATCHER(hasParent);
238   REGISTER_MATCHER(hasQualifier);
239   REGISTER_MATCHER(hasRangeInit);
240   REGISTER_MATCHER(hasReceiverType);
241   REGISTER_MATCHER(hasRHS);
242   REGISTER_MATCHER(hasSelector);
243   REGISTER_MATCHER(hasSingleDecl);
244   REGISTER_MATCHER(hasSize);
245   REGISTER_MATCHER(hasSizeExpr);
246   REGISTER_MATCHER(hasSourceExpression);
247   REGISTER_MATCHER(hasStaticStorageDuration);
248   REGISTER_MATCHER(hasTargetDecl);
249   REGISTER_MATCHER(hasTemplateArgument);
250   REGISTER_MATCHER(hasThen);
251   REGISTER_MATCHER(hasThreadStorageDuration);
252   REGISTER_MATCHER(hasTrueExpression);
253   REGISTER_MATCHER(hasTypeLoc);
254   REGISTER_MATCHER(hasUnaryOperand);
255   REGISTER_MATCHER(hasUnarySelector);
256   REGISTER_MATCHER(hasValueType);
257   REGISTER_MATCHER(ifStmt);
258   REGISTER_MATCHER(ignoringImpCasts);
259   REGISTER_MATCHER(ignoringParenCasts);
260   REGISTER_MATCHER(ignoringParenImpCasts);
261   REGISTER_MATCHER(implicitCastExpr);
262   REGISTER_MATCHER(incompleteArrayType);
263   REGISTER_MATCHER(initListExpr);
264   REGISTER_MATCHER(injectedClassNameType);
265   REGISTER_MATCHER(innerType);
266   REGISTER_MATCHER(integerLiteral);
267   REGISTER_MATCHER(isAnonymous);
268   REGISTER_MATCHER(isAnyCharacter);
269   REGISTER_MATCHER(isAnyPointer);
270   REGISTER_MATCHER(isArrow);
271   REGISTER_MATCHER(isBaseInitializer);
272   REGISTER_MATCHER(isCatchAll);
273   REGISTER_MATCHER(isClass);
274   REGISTER_MATCHER(isConst);
275   REGISTER_MATCHER(isConstQualified);
276   REGISTER_MATCHER(isCopyAssignmentOperator);
277   REGISTER_MATCHER(isCopyConstructor);
278   REGISTER_MATCHER(isDefaultConstructor);
279   REGISTER_MATCHER(isDefaulted);
280   REGISTER_MATCHER(isDefinition);
281   REGISTER_MATCHER(isDeleted);
282   REGISTER_MATCHER(isExceptionVariable);
283   REGISTER_MATCHER(isExplicit);
284   REGISTER_MATCHER(isExplicitTemplateSpecialization);
285   REGISTER_MATCHER(isExpr);
286   REGISTER_MATCHER(isExternC);
287   REGISTER_MATCHER(isFinal);
288   REGISTER_MATCHER(isInline);
289   REGISTER_MATCHER(isImplicit);
290   REGISTER_MATCHER(isExpansionInFileMatching);
291   REGISTER_MATCHER(isExpansionInMainFile);
292   REGISTER_MATCHER(isInstantiated);
293   REGISTER_MATCHER(isExpansionInSystemHeader);
294   REGISTER_MATCHER(isInteger);
295   REGISTER_MATCHER(isIntegral);
296   REGISTER_MATCHER(isInTemplateInstantiation);
297   REGISTER_MATCHER(isListInitialization);
298   REGISTER_MATCHER(isMemberInitializer);
299   REGISTER_MATCHER(isMoveAssignmentOperator);
300   REGISTER_MATCHER(isMoveConstructor);
301   REGISTER_MATCHER(isNoThrow);
302   REGISTER_MATCHER(isOverride);
303   REGISTER_MATCHER(isPrivate);
304   REGISTER_MATCHER(isProtected);
305   REGISTER_MATCHER(isPublic);
306   REGISTER_MATCHER(isPure);
307   REGISTER_MATCHER(isStruct);
308   REGISTER_MATCHER(isTemplateInstantiation);
309   REGISTER_MATCHER(isUnion);
310   REGISTER_MATCHER(isVariadic);
311   REGISTER_MATCHER(isVirtual);
312   REGISTER_MATCHER(isVirtualAsWritten);
313   REGISTER_MATCHER(isVolatileQualified);
314   REGISTER_MATCHER(isWritten);
315   REGISTER_MATCHER(labelStmt);
316   REGISTER_MATCHER(lambdaExpr);
317   REGISTER_MATCHER(lValueReferenceType);
318   REGISTER_MATCHER(matchesName);
319   REGISTER_MATCHER(matchesSelector);
320   REGISTER_MATCHER(materializeTemporaryExpr);
321   REGISTER_MATCHER(member);
322   REGISTER_MATCHER(memberExpr);
323   REGISTER_MATCHER(memberPointerType);
324   REGISTER_MATCHER(namedDecl);
325   REGISTER_MATCHER(namespaceAliasDecl);
326   REGISTER_MATCHER(namespaceDecl);
327   REGISTER_MATCHER(namesType);
328   REGISTER_MATCHER(nestedNameSpecifier);
329   REGISTER_MATCHER(nestedNameSpecifierLoc);
330   REGISTER_MATCHER(nullPointerConstant);
331   REGISTER_MATCHER(nullStmt);
332   REGISTER_MATCHER(numSelectorArgs);
333   REGISTER_MATCHER(ofClass);
334   REGISTER_MATCHER(objcInterfaceDecl);
335   REGISTER_MATCHER(objcMessageExpr);
336   REGISTER_MATCHER(objcObjectPointerType);
337   REGISTER_MATCHER(on);
338   REGISTER_MATCHER(onImplicitObjectArgument);
339   REGISTER_MATCHER(parameterCountIs);
340   REGISTER_MATCHER(parenExpr);
341   REGISTER_MATCHER(parenType);
342   REGISTER_MATCHER(parmVarDecl);
343   REGISTER_MATCHER(pointee);
344   REGISTER_MATCHER(pointerType);
345   REGISTER_MATCHER(qualType);
346   REGISTER_MATCHER(realFloatingPointType);
347   REGISTER_MATCHER(recordDecl);
348   REGISTER_MATCHER(recordType);
349   REGISTER_MATCHER(referenceType);
350   REGISTER_MATCHER(refersToDeclaration);
351   REGISTER_MATCHER(refersToIntegralType);
352   REGISTER_MATCHER(refersToType);
353   REGISTER_MATCHER(returns);
354   REGISTER_MATCHER(returnStmt);
355   REGISTER_MATCHER(rValueReferenceType);
356   REGISTER_MATCHER(sizeOfExpr);
357   REGISTER_MATCHER(specifiesNamespace);
358   REGISTER_MATCHER(specifiesType);
359   REGISTER_MATCHER(specifiesTypeLoc);
360   REGISTER_MATCHER(statementCountIs);
361   REGISTER_MATCHER(staticAssertDecl);
362   REGISTER_MATCHER(stmt);
363   REGISTER_MATCHER(stringLiteral);
364   REGISTER_MATCHER(substNonTypeTemplateParmExpr);
365   REGISTER_MATCHER(substTemplateTypeParmType);
366   REGISTER_MATCHER(switchCase);
367   REGISTER_MATCHER(switchStmt);
368   REGISTER_MATCHER(templateArgument);
369   REGISTER_MATCHER(templateArgumentCountIs);
370   REGISTER_MATCHER(templateSpecializationType);
371   REGISTER_MATCHER(templateTypeParmType);
372   REGISTER_MATCHER(throughUsingDecl);
373   REGISTER_MATCHER(to);
374   REGISTER_MATCHER(translationUnitDecl);
375   REGISTER_MATCHER(type);
376   REGISTER_MATCHER(typedefDecl);
377   REGISTER_MATCHER(typedefType);
378   REGISTER_MATCHER(typeLoc);
379   REGISTER_MATCHER(unaryExprOrTypeTraitExpr);
380   REGISTER_MATCHER(unaryOperator);
381   REGISTER_MATCHER(unaryTransformType);
382   REGISTER_MATCHER(unless);
383   REGISTER_MATCHER(unresolvedUsingTypenameDecl);
384   REGISTER_MATCHER(unresolvedUsingValueDecl);
385   REGISTER_MATCHER(userDefinedLiteral);
386   REGISTER_MATCHER(usingDecl);
387   REGISTER_MATCHER(usingDirectiveDecl);
388   REGISTER_MATCHER(valueDecl);
389   REGISTER_MATCHER(varDecl);
390   REGISTER_MATCHER(variableArrayType);
391   REGISTER_MATCHER(voidType);
392   REGISTER_MATCHER(whileStmt);
393   REGISTER_MATCHER(withInitializer);
394 }
395 
396 RegistryMaps::~RegistryMaps() {
397   llvm::DeleteContainerSeconds(Constructors);
398 }
399 
400 static llvm::ManagedStatic<RegistryMaps> RegistryData;
401 
402 } // anonymous namespace
403 
404 // static
405 llvm::Optional<MatcherCtor> Registry::lookupMatcherCtor(StringRef MatcherName) {
406   ConstructorMap::const_iterator it =
407       RegistryData->constructors().find(MatcherName);
408   return it == RegistryData->constructors().end()
409              ? llvm::Optional<MatcherCtor>()
410              : it->second;
411 }
412 
413 namespace {
414 
415 llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
416                               const std::set<ASTNodeKind> &KS) {
417   unsigned Count = 0;
418   for (std::set<ASTNodeKind>::const_iterator I = KS.begin(), E = KS.end();
419        I != E; ++I) {
420     if (I != KS.begin())
421       OS << "|";
422     if (Count++ == 3) {
423       OS << "...";
424       break;
425     }
426     OS << *I;
427   }
428   return OS;
429 }
430 
431 }  // namespace
432 
433 std::vector<ArgKind> Registry::getAcceptedCompletionTypes(
434     ArrayRef<std::pair<MatcherCtor, unsigned>> Context) {
435   ASTNodeKind InitialTypes[] = {
436       ASTNodeKind::getFromNodeKind<Decl>(),
437       ASTNodeKind::getFromNodeKind<QualType>(),
438       ASTNodeKind::getFromNodeKind<Type>(),
439       ASTNodeKind::getFromNodeKind<Stmt>(),
440       ASTNodeKind::getFromNodeKind<NestedNameSpecifier>(),
441       ASTNodeKind::getFromNodeKind<NestedNameSpecifierLoc>(),
442       ASTNodeKind::getFromNodeKind<TypeLoc>()};
443 
444   // Starting with the above seed of acceptable top-level matcher types, compute
445   // the acceptable type set for the argument indicated by each context element.
446   std::set<ArgKind> TypeSet(std::begin(InitialTypes), std::end(InitialTypes));
447   for (const auto &CtxEntry : Context) {
448     MatcherCtor Ctor = CtxEntry.first;
449     unsigned ArgNumber = CtxEntry.second;
450     std::vector<ArgKind> NextTypeSet;
451     for (const ArgKind &Kind : TypeSet) {
452       if (Kind.getArgKind() == Kind.AK_Matcher &&
453           Ctor->isConvertibleTo(Kind.getMatcherKind()) &&
454           (Ctor->isVariadic() || ArgNumber < Ctor->getNumArgs()))
455         Ctor->getArgKinds(Kind.getMatcherKind(), ArgNumber, NextTypeSet);
456     }
457     TypeSet.clear();
458     TypeSet.insert(NextTypeSet.begin(), NextTypeSet.end());
459   }
460   return std::vector<ArgKind>(TypeSet.begin(), TypeSet.end());
461 }
462 
463 std::vector<MatcherCompletion>
464 Registry::getMatcherCompletions(ArrayRef<ArgKind> AcceptedTypes) {
465   std::vector<MatcherCompletion> Completions;
466 
467   // Search the registry for acceptable matchers.
468   for (const auto &M : RegistryData->constructors()) {
469     const auto *Matcher = M.getValue();
470     StringRef Name = M.getKey();
471 
472     std::set<ASTNodeKind> RetKinds;
473     unsigned NumArgs = Matcher->isVariadic() ? 1 : Matcher->getNumArgs();
474     bool IsPolymorphic = Matcher->isPolymorphic();
475     std::vector<std::vector<ArgKind>> ArgsKinds(NumArgs);
476     unsigned MaxSpecificity = 0;
477     for (const ArgKind& Kind : AcceptedTypes) {
478       if (Kind.getArgKind() != Kind.AK_Matcher)
479         continue;
480       unsigned Specificity;
481       ASTNodeKind LeastDerivedKind;
482       if (Matcher->isConvertibleTo(Kind.getMatcherKind(), &Specificity,
483                                    &LeastDerivedKind)) {
484         if (MaxSpecificity < Specificity)
485           MaxSpecificity = Specificity;
486         RetKinds.insert(LeastDerivedKind);
487         for (unsigned Arg = 0; Arg != NumArgs; ++Arg)
488           Matcher->getArgKinds(Kind.getMatcherKind(), Arg, ArgsKinds[Arg]);
489         if (IsPolymorphic)
490           break;
491       }
492     }
493 
494     if (!RetKinds.empty() && MaxSpecificity > 0) {
495       std::string Decl;
496       llvm::raw_string_ostream OS(Decl);
497 
498       if (IsPolymorphic) {
499         OS << "Matcher<T> " << Name << "(Matcher<T>";
500       } else {
501         OS << "Matcher<" << RetKinds << "> " << Name << "(";
502         for (const std::vector<ArgKind> &Arg : ArgsKinds) {
503           if (&Arg != &ArgsKinds[0])
504             OS << ", ";
505 
506           bool FirstArgKind = true;
507           std::set<ASTNodeKind> MatcherKinds;
508           // Two steps. First all non-matchers, then matchers only.
509           for (const ArgKind &AK : Arg) {
510             if (AK.getArgKind() == ArgKind::AK_Matcher) {
511               MatcherKinds.insert(AK.getMatcherKind());
512             } else {
513               if (!FirstArgKind) OS << "|";
514               FirstArgKind = false;
515               OS << AK.asString();
516             }
517           }
518           if (!MatcherKinds.empty()) {
519             if (!FirstArgKind) OS << "|";
520             OS << "Matcher<" << MatcherKinds << ">";
521           }
522         }
523       }
524       if (Matcher->isVariadic())
525         OS << "...";
526       OS << ")";
527 
528       std::string TypedText = Name;
529       TypedText += "(";
530       if (ArgsKinds.empty())
531         TypedText += ")";
532       else if (ArgsKinds[0][0].getArgKind() == ArgKind::AK_String)
533         TypedText += "\"";
534 
535       Completions.emplace_back(TypedText, OS.str(), MaxSpecificity);
536     }
537   }
538 
539   return Completions;
540 }
541 
542 // static
543 VariantMatcher Registry::constructMatcher(MatcherCtor Ctor,
544                                           SourceRange NameRange,
545                                           ArrayRef<ParserValue> Args,
546                                           Diagnostics *Error) {
547   return Ctor->create(NameRange, Args, Error);
548 }
549 
550 // static
551 VariantMatcher Registry::constructBoundMatcher(MatcherCtor Ctor,
552                                                SourceRange NameRange,
553                                                StringRef BindID,
554                                                ArrayRef<ParserValue> Args,
555                                                Diagnostics *Error) {
556   VariantMatcher Out = constructMatcher(Ctor, NameRange, Args, Error);
557   if (Out.isNull()) return Out;
558 
559   llvm::Optional<DynTypedMatcher> Result = Out.getSingleMatcher();
560   if (Result.hasValue()) {
561     llvm::Optional<DynTypedMatcher> Bound = Result->tryBind(BindID);
562     if (Bound.hasValue()) {
563       return VariantMatcher::SingleMatcher(*Bound);
564     }
565   }
566   Error->addError(NameRange, Error->ET_RegistryNotBindable);
567   return VariantMatcher();
568 }
569 
570 }  // namespace dynamic
571 }  // namespace ast_matchers
572 }  // namespace clang
573