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 #include <optional> 16 17 namespace lldb_private { 18 19 /// Handles importing decls into an ASTContext with an attached C++ module. 20 /// 21 /// This class searches a C++ module (which must be attached to the target 22 /// ASTContext) for an equivalent decl to the one that should be imported. 23 /// If the decl that is found in the module is a suitable replacement 24 /// for the decl that should be imported, the module decl will be treated as 25 /// the result of the import process. 26 /// 27 /// If the Decl that should be imported is a template specialization 28 /// that doesn't exist yet in the target ASTContext (e.g. `std::vector<int>`), 29 /// then this class tries to create the template specialization in the target 30 /// ASTContext. This is only possible if the CxxModuleHandler can determine 31 /// that instantiating this template is safe to do, e.g. because the target 32 /// decl is a container class from the STL. 33 class CxxModuleHandler { 34 /// The ASTImporter that should be used to import any Decls which aren't 35 /// directly handled by this class itself. 36 clang::ASTImporter *m_importer = nullptr; 37 38 /// The Sema instance of the target ASTContext. 39 clang::Sema *m_sema = nullptr; 40 41 /// List of template names this class currently supports. These are the 42 /// template names inside the 'std' namespace such as 'vector' or 'list'. 43 llvm::StringSet<> m_supported_templates; 44 45 /// Tries to manually instantiate the given foreign template in the target 46 /// context (designated by m_sema). 47 std::optional<clang::Decl *> tryInstantiateStdTemplate(clang::Decl *d); 48 49 public: 50 CxxModuleHandler() = default; 51 CxxModuleHandler(clang::ASTImporter &importer, clang::ASTContext *target); 52 53 /// Attempts to import the given decl into the target ASTContext by 54 /// deserializing it from the 'std' module. This function returns a Decl if a 55 /// Decl has been deserialized from the 'std' module. Otherwise this function 56 /// returns nothing. 57 std::optional<clang::Decl *> Import(clang::Decl *d); 58 59 /// Returns true iff this instance is capable of importing any declarations 60 /// in the target ASTContext. 61 bool isValid() const { return m_sema != nullptr; } 62 }; 63 64 } // namespace lldb_private 65 66 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CXXMODULEHANDLER_H 67