1 //===-- CxxModuleHandler.h --------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CXXMODULEHANDLER_H 10 #define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CXXMODULEHANDLER_H 11 12 #include "clang/AST/ASTImporter.h" 13 #include "clang/Sema/Sema.h" 14 #include "llvm/ADT/StringSet.h" 15 16 namespace lldb_private { 17 18 /// Handles importing decls into an ASTContext with an attached C++ module. 19 /// 20 /// This class searches a C++ module (which must be attached to the target 21 /// ASTContext) for an equivalent decl to the one that should be imported. 22 /// If the decl that is found in the module is a suitable replacement 23 /// for the decl that should be imported, the module decl will be treated as 24 /// the result of the import process. 25 /// 26 /// If the Decl that should be imported is a template specialization 27 /// that doesn't exist yet in the target ASTContext (e.g. `std::vector<int>`), 28 /// then this class tries to create the template specialization in the target 29 /// ASTContext. This is only possible if the CxxModuleHandler can determine 30 /// that instantiating this template is safe to do, e.g. because the target 31 /// decl is a container class from the STL. 32 class CxxModuleHandler { 33 /// The ASTImporter that should be used to import any Decls which aren't 34 /// directly handled by this class itself. 35 clang::ASTImporter *m_importer = nullptr; 36 37 /// The Sema instance of the target ASTContext. 38 clang::Sema *m_sema = nullptr; 39 40 /// List of template names this class currently supports. These are the 41 /// template names inside the 'std' namespace such as 'vector' or 'list'. 42 llvm::StringSet<> m_supported_templates; 43 44 /// Tries to manually instantiate the given foreign template in the target 45 /// context (designated by m_sema). 46 llvm::Optional<clang::Decl *> tryInstantiateStdTemplate(clang::Decl *d); 47 48 public: 49 CxxModuleHandler() = default; 50 CxxModuleHandler(clang::ASTImporter &importer, clang::ASTContext *target); 51 52 /// Attempts to import the given decl into the target ASTContext by 53 /// deserializing it from the 'std' module. This function returns a Decl if a 54 /// Decl has been deserialized from the 'std' module. Otherwise this function 55 /// returns nothing. 56 llvm::Optional<clang::Decl *> Import(clang::Decl *d); 57 58 /// Returns true iff this instance is capable of importing any declarations 59 /// in the target ASTContext. 60 bool isValid() const { return m_sema != nullptr; } 61 }; 62 63 } // namespace lldb_private 64 65 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CXXMODULEHANDLER_H 66