1 //===-- ClangUserExpression.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_CLANGUSEREXPRESSION_H 10 #define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGUSEREXPRESSION_H 11 12 #include <optional> 13 #include <vector> 14 15 #include "ASTResultSynthesizer.h" 16 #include "ASTStructExtractor.h" 17 #include "ClangExpressionDeclMap.h" 18 #include "ClangExpressionHelper.h" 19 #include "ClangExpressionSourceCode.h" 20 #include "ClangExpressionVariable.h" 21 #include "IRForTarget.h" 22 23 #include "lldb/Core/Address.h" 24 #include "lldb/Expression/LLVMUserExpression.h" 25 #include "lldb/Expression/Materializer.h" 26 #include "lldb/Target/ExecutionContext.h" 27 #include "lldb/lldb-forward.h" 28 #include "lldb/lldb-private.h" 29 30 namespace lldb_private { 31 32 class ClangExpressionParser; 33 34 /// \class ClangUserExpression ClangUserExpression.h 35 /// "lldb/Expression/ClangUserExpression.h" Encapsulates a single expression 36 /// for use with Clang 37 /// 38 /// LLDB uses expressions for various purposes, notably to call functions 39 /// and as a backend for the expr command. ClangUserExpression encapsulates 40 /// the objects needed to parse and interpret or JIT an expression. It uses 41 /// the Clang parser to produce LLVM IR from the expression. 42 class ClangUserExpression : public LLVMUserExpression { 43 // LLVM RTTI support 44 static char ID; 45 46 public: 47 bool isA(const void *ClassID) const override { 48 return ClassID == &ID || LLVMUserExpression::isA(ClassID); 49 } 50 static bool classof(const Expression *obj) { return obj->isA(&ID); } 51 52 enum { kDefaultTimeout = 500000u }; 53 54 class ClangUserExpressionHelper 55 : public llvm::RTTIExtends<ClangUserExpressionHelper, 56 ClangExpressionHelper> { 57 public: 58 // LLVM RTTI support 59 static char ID; 60 61 ClangUserExpressionHelper(Target &target, bool top_level) 62 : m_target(target), m_top_level(top_level) {} 63 64 /// Return the object that the parser should use when resolving external 65 /// values. May be NULL if everything should be self-contained. 66 ClangExpressionDeclMap *DeclMap() override { 67 return m_expr_decl_map_up.get(); 68 } 69 70 void ResetDeclMap() { m_expr_decl_map_up.reset(); } 71 72 void ResetDeclMap(ExecutionContext &exe_ctx, 73 Materializer::PersistentVariableDelegate &result_delegate, 74 bool keep_result_in_memory, 75 ValueObject *ctx_obj); 76 77 /// Return the object that the parser should allow to access ASTs. May be 78 /// NULL if the ASTs do not need to be transformed. 79 /// 80 /// \param[in] passthrough 81 /// The ASTConsumer that the returned transformer should send 82 /// the ASTs to after transformation. 83 clang::ASTConsumer * 84 ASTTransformer(clang::ASTConsumer *passthrough) override; 85 86 void CommitPersistentDecls() override; 87 88 private: 89 Target &m_target; 90 std::unique_ptr<ClangExpressionDeclMap> m_expr_decl_map_up; 91 std::unique_ptr<ASTStructExtractor> m_struct_extractor_up; ///< The class 92 ///that generates 93 ///the argument 94 ///struct layout. 95 std::unique_ptr<ASTResultSynthesizer> m_result_synthesizer_up; 96 bool m_top_level; 97 }; 98 99 /// Constructor 100 /// 101 /// \param[in] expr 102 /// The expression to parse. 103 /// 104 /// \param[in] prefix 105 /// If non-NULL, a C string containing translation-unit level 106 /// definitions to be included when the expression is parsed. 107 /// 108 /// \param[in] language 109 /// If not unknown, a language to use when parsing the 110 /// expression. Currently restricted to those languages 111 /// supported by Clang. 112 /// 113 /// \param[in] desired_type 114 /// If not eResultTypeAny, the type to use for the expression 115 /// result. 116 /// 117 /// \param[in] options 118 /// Additional options for the expression. 119 /// 120 /// \param[in] ctx_obj 121 /// The object (if any) in which context the expression 122 /// must be evaluated. For details see the comment to 123 /// `UserExpression::Evaluate`. 124 ClangUserExpression(ExecutionContextScope &exe_scope, llvm::StringRef expr, 125 llvm::StringRef prefix, SourceLanguage language, 126 ResultType desired_type, 127 const EvaluateExpressionOptions &options, 128 ValueObject *ctx_obj); 129 130 ~ClangUserExpression() override; 131 132 /// Parse the expression 133 /// 134 /// \param[in] diagnostic_manager 135 /// A diagnostic manager to report parse errors and warnings to. 136 /// 137 /// \param[in] exe_ctx 138 /// The execution context to use when looking up entities that 139 /// are needed for parsing (locations of functions, types of 140 /// variables, persistent variables, etc.) 141 /// 142 /// \param[in] execution_policy 143 /// Determines whether interpretation is possible or mandatory. 144 /// 145 /// \param[in] keep_result_in_memory 146 /// True if the resulting persistent variable should reside in 147 /// target memory, if applicable. 148 /// 149 /// \return 150 /// True on success (no errors); false otherwise. 151 bool Parse(DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 152 lldb_private::ExecutionPolicy execution_policy, 153 bool keep_result_in_memory, bool generate_debug_info) override; 154 155 bool Complete(ExecutionContext &exe_ctx, CompletionRequest &request, 156 unsigned complete_pos) override; 157 158 ExpressionTypeSystemHelper *GetTypeSystemHelper() override { 159 return &m_type_system_helper; 160 } 161 162 ClangExpressionDeclMap *DeclMap() { return m_type_system_helper.DeclMap(); } 163 164 void ResetDeclMap() { m_type_system_helper.ResetDeclMap(); } 165 166 void ResetDeclMap(ExecutionContext &exe_ctx, 167 Materializer::PersistentVariableDelegate &result_delegate, 168 bool keep_result_in_memory) { 169 m_type_system_helper.ResetDeclMap(exe_ctx, result_delegate, 170 keep_result_in_memory, 171 m_ctx_obj); 172 } 173 174 lldb::ExpressionVariableSP 175 GetResultAfterDematerialization(ExecutionContextScope *exe_scope) override; 176 177 /// Returns true iff this expression is using any imported C++ modules. 178 bool DidImportCxxModules() const { return !m_imported_cpp_modules.empty(); } 179 180 llvm::StringRef GetFilename() const { return m_filename; } 181 182 private: 183 /// Populate m_in_cplusplus_method and m_in_objectivec_method based on the 184 /// environment. 185 186 /// Contains the actual parsing implementation. 187 /// The parameter have the same meaning as in ClangUserExpression::Parse. 188 /// \see ClangUserExpression::Parse 189 bool TryParse(DiagnosticManager &diagnostic_manager, 190 ExecutionContext &exe_ctx, 191 lldb_private::ExecutionPolicy execution_policy, 192 bool keep_result_in_memory, bool generate_debug_info); 193 194 void SetupCppModuleImports(ExecutionContext &exe_ctx); 195 196 void ScanContext(ExecutionContext &exe_ctx, 197 lldb_private::Status &err) override; 198 199 bool AddArguments(ExecutionContext &exe_ctx, std::vector<lldb::addr_t> &args, 200 lldb::addr_t struct_address, 201 DiagnosticManager &diagnostic_manager) override; 202 203 void CreateSourceCode(DiagnosticManager &diagnostic_manager, 204 ExecutionContext &exe_ctx, 205 std::vector<std::string> modules_to_import, 206 bool for_completion); 207 208 lldb::addr_t GetCppObjectPointer(lldb::StackFrameSP frame, 209 llvm::StringRef object_name, Status &err); 210 211 /// Defines how the current expression should be wrapped. 212 ClangExpressionSourceCode::WrapKind GetWrapKind() const; 213 bool SetupPersistentState(DiagnosticManager &diagnostic_manager, 214 ExecutionContext &exe_ctx); 215 bool PrepareForParsing(DiagnosticManager &diagnostic_manager, 216 ExecutionContext &exe_ctx, bool for_completion); 217 218 ClangUserExpressionHelper m_type_system_helper; 219 220 class ResultDelegate : public Materializer::PersistentVariableDelegate { 221 public: 222 ResultDelegate(lldb::TargetSP target) : m_target_sp(target) {} 223 ConstString GetName() override; 224 void DidDematerialize(lldb::ExpressionVariableSP &variable) override; 225 226 void RegisterPersistentState(PersistentExpressionState *persistent_state); 227 lldb::ExpressionVariableSP &GetVariable(); 228 229 private: 230 PersistentExpressionState *m_persistent_state; 231 lldb::ExpressionVariableSP m_variable; 232 lldb::TargetSP m_target_sp; 233 }; 234 235 /// The include directories that should be used when parsing the expression. 236 std::vector<std::string> m_include_directories; 237 238 /// The absolute character position in the transformed source code where the 239 /// user code (as typed by the user) starts. If the variable is empty, then we 240 /// were not able to calculate this position. 241 std::optional<size_t> m_user_expression_start_pos; 242 ResultDelegate m_result_delegate; 243 ClangPersistentVariables *m_clang_state; 244 std::unique_ptr<ClangExpressionSourceCode> m_source_code; 245 /// The parser instance we used to parse the expression. 246 std::unique_ptr<ClangExpressionParser> m_parser; 247 /// File name used for the expression. 248 std::string m_filename; 249 250 /// The object (if any) in which context the expression is evaluated. 251 /// See the comment to `UserExpression::Evaluate` for details. 252 ValueObject *m_ctx_obj; 253 254 /// A list of module names that should be imported when parsing. 255 /// \see CppModuleConfiguration::GetImportedModules 256 std::vector<std::string> m_imported_cpp_modules; 257 258 /// True if the expression parser should enforce the presence of a valid class 259 /// pointer in order to generate the expression as a method. 260 bool m_enforce_valid_object = true; 261 /// True if the expression is compiled as a C++ member function (true if it 262 /// was parsed when exe_ctx was in a C++ method). 263 bool m_in_cplusplus_method = false; 264 /// True if the expression is compiled as an Objective-C method (true if it 265 /// was parsed when exe_ctx was in an Objective-C method). 266 bool m_in_objectivec_method = false; 267 /// True if the expression is compiled as a static (or class) method 268 /// (currently true if it was parsed when exe_ctx was in an Objective-C class 269 /// method). 270 bool m_in_static_method = false; 271 /// True if "this" or "self" must be looked up and passed in. False if the 272 /// expression doesn't really use them and they can be NULL. 273 bool m_needs_object_ptr = false; 274 }; 275 276 } // namespace lldb_private 277 278 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGUSEREXPRESSION_H 279