Swift 高性能系统编程语言

//===--- CSSimplify.cpp - Constraint Simplification -----------------------===// // // This source file is part of the Swift.org open source project // // Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors // Licensed under Apache License v2.0 with Runtime Library Exception // // See https://swift.org/LICENSE.txt for license information // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors // //===----------------------------------------------------------------------===// // // This file implements simplifications of constraints within the constraint // system. // //===----------------------------------------------------------------------===// #include "CSDiagnostics.h" #include "TypeCheckConcurrency.h" #include "TypeCheckEffects.h" #include "swift/AST/ASTPrinter.h" #include "swift/AST/Decl.h" #include "swift/AST/ExistentialLayout.h" #include "swift/AST/GenericEnvironment.h" #include "swift/AST/GenericSignature.h" #include "swift/AST/Initializer.h" #include "swift/AST/NameLookupRequests.h" #include "swift/AST/PackExpansionMatcher.h" #include "swift/AST/ParameterList.h" #include "swift/AST/PropertyWrappers.h" #include "swift/AST/ProtocolConformance.h" #include "swift/AST/Requirement.h" #include "swift/AST/SourceFile.h" #include "swift/AST/Types.h" #include "swift/Basic/Assertions.h" #include "swift/Basic/StringExtras.h" #include "swift/ClangImporter/ClangModule.h" #include "swift/Sema/CSFix.h" #include "swift/Sema/ConstraintSystem.h" #include "swift/Sema/IDETypeChecking.h" #include "llvm/ADT/SetVector.h" #include "llvm/Support/Compiler.h" using namespace swift; using namespace constraints; MatchCallArgumentListener::~MatchCallArgumentListener() { } bool MatchCallArgumentListener::extraArgument(unsigned argIdx) { return true; } std::optional MatchCallArgumentListener::missingArgument(unsigned paramIdx, unsigned argInsertIdx) { return std::nullopt; } bool MatchCallArgumentListener::missingLabel(unsigned paramIdx) { return true; } bool MatchCallArgumentListener::extraneousLabel(unsigned paramIdx) { return true; } bool MatchCallArgumentListener::incorrectLabel(unsigned paramIdx) { return true; } bool MatchCallArgumentListener::outOfOrderArgument( unsigned argIdx, unsigned prevArgIdx, ArrayRef bindings) { return true; } bool MatchCallArgumentListener::relabelArguments(ArrayRef newNames){ return true; } bool MatchCallArgumentListener::shouldClaimArgDuringRecovery(unsigned argIdx) { return true; } bool MatchCallArgumentListener::canClaimArgIgnoringNameMismatch( const AnyFunctionType::Param &arg) { return false; } /// Produce a score (smaller is better) comparing a parameter name and /// potentially-typo'd argument name. /// /// \param paramName The name of the parameter. /// \param argName The name of the argument. /// \param maxScore The maximum score permitted by this comparison, or /// 0 if there is no limit. /// /// \returns the score, if it is good enough to even consider this a match. /// Otherwise, an empty optional. /// static std::optional scoreParamAndArgNameTypo(StringRef paramName, StringRef argName, unsigned maxScore) { using namespace camel_case; // Compute the edit distance. unsigned dist = argName.edit_distance(paramName, /*AllowReplacements=*/true, /*MaxEditDistance=*/maxScore); // If the edit distance would be too long, we're done. if (maxScore != 0 && dist > maxScore) return std::nullopt; // The distance can be zero due to the "with" transformation above. if (dist == 0) return 1; // If this is just a single character label on both sides, // simply return distance. if (paramName.size() == 1 && argName.size() == 1) return dist; // Only allow about one typo for every two properly-typed characters, which // prevents completely-wacky suggestions in many cases. if (dist > (argName.size() + 1) / 3) return std::nullopt; return dist; } bool constraints::isPackExpansionType(Type type) { if (type->is()) return true; if (auto *typeVar = type->getAs()) return typeVar->getImpl().isPackExpansion(); return false; } bool constraints::isSingleUnlabeledPackExpansionTuple(Type type) { auto *tuple = type->getRValueType()->getAs(); return tuple && (tuple->getNumElements() == 1) && isPackExpansionType(tuple->getElementType(0)) && !tuple->getElement(0).hasName(); } Type constraints::getPatternTypeOfSingleUnlabeledPackExpansionTuple(Type type) { if (isSingleUnlabeledPackExpansionTuple(type)) { auto tuple = type->getRValueType()->castTo(); const auto &tupleElement = tuple->getElementType(0); if (auto *expansion = tupleElement->getAs()) { return expansion->getPatternType(); } if (auto *typeVar = tupleElement->getAs()) { auto *locator = typeVar->getImpl().getLocator(); if (auto expansionElement = locator->getLastElementAs()) { return expansionElement->getOpenedType()->getPatternType(); } } } return {}; } bool constraints::containsPackExpansionType(ArrayRef params) { return llvm::any_of(params, [&](const auto ¶m) { return isPackExpansionType(param.getPlainType()); }); } bool constraints::containsPackExpansionType(TupleType *tuple) { return llvm::any_of(tuple->getElements(), [&](const auto &elt) { return isPackExpansionType(elt.getType()); }); } bool constraints::doesMemberRefApplyCurriedSelf(Type baseTy, const ValueDecl *decl) { assert(decl->getDeclContext()->isTypeContext() && "Expected a member reference"); // For a reference to an instance method on a metatype, we want to keep the // curried self. if (decl->isInstanceMember()) { assert(baseTy); if (isa(decl) && baseTy->getRValueType()->is()) return false; } // Otherwise the reference applies self. return true; } static bool areConservativelyCompatibleArgumentLabels( ConstraintSystem &cs, OverloadChoice choice, SmallVectorImpl &args, MatchCallArgumentListener &listener, std::optional unlabeledTrailingClosureArgIndex) { ValueDecl *decl = nullptr; switch (choice.getKind()) { case OverloadChoiceKind::Decl: case OverloadChoiceKind::DeclViaBridge: case OverloadChoiceKind::DeclViaDynamic: case OverloadChoiceKind::DeclViaUnwrappedOptional: decl = choice.getDecl(); break; // KeyPath application is not filtered in `performMemberLookup`. case OverloadChoiceKind::KeyPathApplication: case OverloadChoiceKind::DynamicMemberLookup: case OverloadChoiceKind::KeyPathDynamicMemberLookup: case OverloadChoiceKind::TupleIndex: case OverloadChoiceKind::MaterializePack: case OverloadChoiceKind::ExtractFunctionIsolation: return true; } // If this is a member lookup, the call arguments (if we have any) will // generally be applied to the second level of parameters, with the member // lookup applying the curried self at the first level. But there are cases // where we can get an unapplied declaration reference back. auto hasAppliedSelf = decl->hasCurriedSelf() && doesMemberRefApplyCurriedSelf(choice.getBaseType(), decl); AnyFunctionType *fnType = nullptr; if (decl->hasParameterList()) { fnType = decl->getInterfaceType()->castTo(); if (hasAppliedSelf) { fnType = fnType->getResult()->getAs(); assert(fnType && "Parameter list curry level does not match type"); } } else if (auto *VD = dyn_cas