================ @@ -0,0 +1,349 @@ +//===--- AddPureVirtualOverride.cpp ------------------------------*- C++-*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "refactor/Tweak.h" + +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/Type.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Basic/LLVM.h" +#include "clang/Basic/SourceLocation.h" +#include "clang/Tooling/Core/Replacement.h" +#include "llvm/ADT/DenseSet.h" +#include "llvm/Support/FormatVariadic.h" +#include <algorithm> +#include <functional> +#include <map> +#include <set> +#include <string> +#include <vector> + +namespace clang { +namespace clangd { +namespace { + +class OverridePureVirtuals : public Tweak { +public: + const char *id() const final; // defined by REGISTER_TWEAK. + bool prepare(const Selection &Sel) override; + Expected<Effect> apply(const Selection &Sel) override; + std::string title() const override { return "Override pure virtual methods"; } + llvm::StringLiteral kind() const override { + return CodeAction::REFACTOR_KIND; + } + +private: + // Stores the CXXRecordDecl of the class being modified. + const CXXRecordDecl *CurrentDecl = nullptr; + // Stores pure virtual methods that need overriding, grouped by their original + // access specifier. + std::map<AccessSpecifier, std::vector<const CXXMethodDecl *>> + MissingMethodsByAccess; + // Stores the source locations of existing access specifiers in CurrentDecl. + std::map<AccessSpecifier, SourceLocation> AccessSpecifierLocations; + + // Helper function to gather information before applying the tweak. + void collectMissingPureVirtuals(const Selection &Sel); +}; + +REGISTER_TWEAK(OverridePureVirtuals) + +// Collects all unique, canonical pure virtual methods from a class and its +// entire inheritance hierarchy. This function aims to find methods that *could* +// make a derived class abstract if not implemented. +std::vector<const CXXMethodDecl *> +getAllUniquePureVirtualsFromHierarchy(const CXXRecordDecl *Decl) { + std::vector<const CXXMethodDecl *> Result; + llvm::DenseSet<const CXXMethodDecl *> VisitedCanonicalMethods; + // We declare it as a std::function because we are going to call it + // recursively. + std::function<void(const CXXRecordDecl *)> Collect; + + Collect = [&](const CXXRecordDecl *CurrentClass) { + if (!CurrentClass) { + return; + } + const CXXRecordDecl *Def = CurrentClass->getDefinition(); + if (!Def) { + return; + } + + for (const CXXMethodDecl *M : Def->methods()) { + // Add if its canonical declaration hasn't been processed yet. + // This ensures each distinct pure virtual method signature is collected + // once. + if (M->isPureVirtual() && + VisitedCanonicalMethods.insert(M->getCanonicalDecl()).second) { + Result.emplace_back(M); // Store the specific declaration encountered. + } + } + + for (const auto &BaseSpec : Def->bases()) { + if (const CXXRecordDecl *BaseDef = + BaseSpec.getType()->getAsCXXRecordDecl()) { + Collect(BaseDef); // Recursively collect from base classes. + } + } + }; + + Collect(Decl); + return Result; +} + +// Gets canonical declarations of methods already overridden or implemented in +// class D. +std::set<const CXXMethodDecl *> +getImplementedOrOverriddenCanonicals(const CXXRecordDecl *D) { + std::set<const CXXMethodDecl *> ImplementedSet; + for (const CXXMethodDecl *M : D->methods()) { + // If M provides an implementation for any virtual method it overrides. + // A method is an "implementation" if it's virtual and not pure. + // Or if it directly overrides a base method. + for (const CXXMethodDecl *OverriddenM : M->overridden_methods()) { + ImplementedSet.insert(OverriddenM->getCanonicalDecl()); + } + } + return ImplementedSet; +} + +// Get the location of every colon of the `AccessSpecifier`. +std::map<AccessSpecifier, SourceLocation> +getSpecifierLocations(const CXXRecordDecl *D) { + std::map<AccessSpecifier, SourceLocation> Locs; + for (auto *DeclNode : D->decls()) { // Changed to DeclNode to avoid ambiguity + if (const auto *ASD = llvm::dyn_cast<AccessSpecDecl>(DeclNode)) { + Locs[ASD->getAccess()] = ASD->getColonLoc(); + } + } + return Locs; +} + +// Check if the current class has any pure virtual method to be implemented. +bool OverridePureVirtuals::prepare(const Selection &Sel) { + const SelectionTree::Node *Node = Sel.ASTSelection.commonAncestor(); + if (!Node) { + return false; + } + + // Make sure we have a definition. + CurrentDecl = Node->ASTNode.get<CXXRecordDecl>(); + if (!CurrentDecl || !CurrentDecl->getDefinition()) { + return false; + } + + // A class needs overrides if it's abstract itself, or derives from abstract + // bases and hasn't implemented all necessary methods. A simpler check: if it + // has any base that is abstract. + bool HasAbstractBase = false; + for (const auto &Base : CurrentDecl->bases()) { + if (const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl()) { + if (BaseDecl->getDefinition() && + BaseDecl->getDefinition()->isAbstract()) { + HasAbstractBase = true; + break; + } + } + } + + // Only offer for polymorphic classes with abstract bases. + return CurrentDecl->isPolymorphic() && HasAbstractBase; +} + +// Collects all pure virtual methods that are missing an override in +// CurrentDecl, grouped by their original access specifier. +void OverridePureVirtuals::collectMissingPureVirtuals(const Selection &Sel) { + if (!CurrentDecl) + return; + CurrentDecl = CurrentDecl->getDefinition(); // Work with the definition + if (!CurrentDecl) + return; + + AccessSpecifierLocations = getSpecifierLocations(CurrentDecl); + MissingMethodsByAccess.clear(); + + // Get all unique pure virtual methods from the entire base class hierarchy. + std::vector<const CXXMethodDecl *> AllPureVirtualsInHierarchy; + llvm::DenseSet<const CXXMethodDecl *> CanonicalPureVirtualsSeen; + + for (const auto &BaseSpec : CurrentDecl->bases()) { + if (const CXXRecordDecl *BaseRD = + BaseSpec.getType()->getAsCXXRecordDecl()) { + const CXXRecordDecl *BaseDef = BaseRD->getDefinition(); + if (!BaseDef) + continue; + + std::vector<const CXXMethodDecl *> PuresFromBasePath = + getAllUniquePureVirtualsFromHierarchy(BaseDef); + for (const CXXMethodDecl *M : PuresFromBasePath) { + if (CanonicalPureVirtualsSeen.insert(M->getCanonicalDecl()).second) { + AllPureVirtualsInHierarchy.emplace_back(M); + } + } + } + } + + // Get methods already implemented or overridden in CurrentDecl. + const auto ImplementedOrOverriddenSet = + getImplementedOrOverriddenCanonicals(CurrentDecl); + + // Filter AllPureVirtualsInHierarchy to find those not in + // ImplementedOrOverriddenSet. + for (const CXXMethodDecl *BaseMethod : AllPureVirtualsInHierarchy) { + bool AlreadyHandled = + ImplementedOrOverriddenSet.count(BaseMethod->getCanonicalDecl()) > 0; + + if (!AlreadyHandled) { + // This method needs an override. + // Group it by its access specifier in its defining class. + MissingMethodsByAccess[BaseMethod->getAccess()].emplace_back(BaseMethod); + } + } +} + +// Free function to generate the string for a group of method overrides. +std::string +generateOverridesStringForGroup(std::vector<const CXXMethodDecl *> Methods, + const LangOptions &LangOpts) { + const auto GetParamString = [&LangOpts](const ParmVarDecl *P) { + std::string TypeStr = P->getType().getAsString(LangOpts); + if (P->getNameAsString().empty()) { + // Unnamed parameter. + return TypeStr; + } + return llvm::formatv("{0} {1}", TypeStr, P->getNameAsString()).str(); + }; + + std::string MethodsString; + for (const auto *Method : Methods) { + std::vector<std::string> ParamsAsString; + ParamsAsString.reserve(Method->parameters().size()); + std::transform(Method->param_begin(), Method->param_end(), + std::back_inserter(ParamsAsString), GetParamString); + const auto Params = llvm::join(ParamsAsString, ", "); + + MethodsString += + llvm::formatv( + " {0} {1}({2}) {3}override {{\n" + " // TODO: Implement this pure virtual method\n" + " static_assert(false, \"Method `{1}` is not implemented.\");\n" + " }\n", + Method->getReturnType().getAsString(LangOpts), + Method->getNameAsString(), Params, ---------------- marcogmaia wrote:
Added. https://github.com/llvm/llvm-project/pull/139348 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
