1 //===-- ClangExpressionVariable.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_CLANGEXPRESSIONVARIABLE_H 10 #define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONVARIABLE_H 11 12 #include <csignal> 13 #include <cstdint> 14 #include <cstring> 15 16 #include <map> 17 #include <string> 18 #include <vector> 19 20 #include "llvm/Support/Casting.h" 21 22 #include "lldb/Core/Value.h" 23 #include "lldb/Expression/ExpressionVariable.h" 24 #include "lldb/Symbol/TaggedASTType.h" 25 #include "lldb/Utility/ConstString.h" 26 #include "lldb/lldb-public.h" 27 28 namespace llvm { 29 class Value; 30 } 31 32 namespace clang { 33 class NamedDecl; 34 } 35 36 namespace lldb_private { 37 38 class ValueObjectConstResult; 39 40 /// \class ClangExpressionVariable ClangExpressionVariable.h 41 /// "lldb/Expression/ClangExpressionVariable.h" Encapsulates one variable for 42 /// the expression parser. 43 /// 44 /// The expression parser uses variables in three different contexts: 45 /// 46 /// First, it stores persistent variables along with the process for use in 47 /// expressions. These persistent variables contain their own data and are 48 /// typed. 49 /// 50 /// Second, in an interpreted expression, it stores the local variables for 51 /// the expression along with the expression. These variables contain their 52 /// own data and are typed. 53 /// 54 /// Third, in a JIT-compiled expression, it stores the variables that the 55 /// expression needs to have materialized and dematerialized at each 56 /// execution. These do not contain their own data but are named and typed. 57 /// 58 /// This class supports all of these use cases using simple type polymorphism, 59 /// and provides necessary support methods. Its interface is RTTI-neutral. 60 class ClangExpressionVariable 61 : public llvm::RTTIExtends<ClangExpressionVariable, ExpressionVariable> { 62 public: 63 // LLVM RTTI support 64 static char ID; 65 66 ClangExpressionVariable(ExecutionContextScope *exe_scope, 67 lldb::ByteOrder byte_order, uint32_t addr_byte_size); 68 69 ClangExpressionVariable(ExecutionContextScope *exe_scope, Value &value, 70 ConstString name, uint16_t flags = EVNone); 71 72 ClangExpressionVariable(const lldb::ValueObjectSP &valobj_sp); 73 74 ClangExpressionVariable(ExecutionContextScope *exe_scope, 75 ConstString name, 76 const TypeFromUser &user_type, 77 lldb::ByteOrder byte_order, uint32_t addr_byte_size); 78 79 /// Utility functions for dealing with ExpressionVariableLists in Clang- 80 /// specific ways 81 82 /// Finds a variable by NamedDecl in the list. 83 /// 84 /// \return 85 /// The variable requested, or NULL if that variable is not in the list. 86 static ClangExpressionVariable * FindVariableInList(ExpressionVariableList & list,const clang::NamedDecl * decl,uint64_t parser_id)87 FindVariableInList(ExpressionVariableList &list, const clang::NamedDecl *decl, 88 uint64_t parser_id) { 89 lldb::ExpressionVariableSP var_sp; 90 for (size_t index = 0, size = list.GetSize(); index < size; ++index) { 91 var_sp = list.GetVariableAtIndex(index); 92 93 if (ClangExpressionVariable *clang_var = 94 llvm::dyn_cast<ClangExpressionVariable>(var_sp.get())) { 95 ClangExpressionVariable::ParserVars *parser_vars = 96 clang_var->GetParserVars(parser_id); 97 98 if (parser_vars && parser_vars->m_named_decl == decl) 99 return clang_var; 100 } 101 } 102 return nullptr; 103 } 104 105 /// If the variable contains its own data, make a Value point at it. If \a 106 /// exe_ctx in not NULL, the value will be resolved in with that execution 107 /// context. 108 /// 109 /// \param[in] value 110 /// The value to point at the data. 111 /// 112 /// \param[in] exe_ctx 113 /// The execution context to use to resolve \a value. 114 /// 115 /// \return 116 /// True on success; false otherwise (in particular, if this variable 117 /// does not contain its own data). 118 bool PointValueAtData(Value &value, ExecutionContext *exe_ctx); 119 120 /// The following values should not live beyond parsing 121 class ParserVars { 122 public: 123 ParserVars() = default; 124 125 const clang::NamedDecl *m_named_decl = 126 nullptr; ///< The Decl corresponding to this variable 127 llvm::Value *m_llvm_value = 128 nullptr; ///< The IR value corresponding to this variable; 129 /// usually a GlobalValue 130 lldb_private::Value 131 m_lldb_value; ///< The value found in LLDB for this variable 132 lldb::VariableSP m_lldb_var; ///< The original variable for this variable 133 const lldb_private::Symbol *m_lldb_sym = 134 nullptr; ///< The original symbol for this 135 /// variable, if it was a symbol 136 137 /// Callback that provides a ValueObject for the 138 /// specified frame. Used by the materializer for 139 /// re-fetching ValueObjects when materializing 140 /// ivars. 141 ValueObjectProviderTy m_lldb_valobj_provider; 142 }; 143 144 private: 145 typedef std::map<uint64_t, ParserVars> ParserVarMap; 146 ParserVarMap m_parser_vars; 147 148 public: 149 /// Make this variable usable by the parser by allocating space for parser- 150 /// specific variables EnableParserVars(uint64_t parser_id)151 void EnableParserVars(uint64_t parser_id) { 152 m_parser_vars.insert(std::make_pair(parser_id, ParserVars())); 153 } 154 155 /// Deallocate parser-specific variables DisableParserVars(uint64_t parser_id)156 void DisableParserVars(uint64_t parser_id) { m_parser_vars.erase(parser_id); } 157 158 /// Access parser-specific variables GetParserVars(uint64_t parser_id)159 ParserVars *GetParserVars(uint64_t parser_id) { 160 ParserVarMap::iterator i = m_parser_vars.find(parser_id); 161 162 if (i == m_parser_vars.end()) 163 return nullptr; 164 else 165 return &i->second; 166 } 167 168 /// The following values are valid if the variable is used by JIT code 169 struct JITVars { 170 JITVars() = default; 171 172 lldb::offset_t m_alignment = 173 0; ///< The required alignment of the variable, in bytes 174 size_t m_size = 0; ///< The space required for the variable, in bytes 175 lldb::offset_t m_offset = 176 0; ///< The offset of the variable in the struct, in bytes 177 }; 178 179 private: 180 typedef std::map<uint64_t, JITVars> JITVarMap; 181 JITVarMap m_jit_vars; 182 183 public: 184 /// Make this variable usable for materializing for the JIT by allocating 185 /// space for JIT-specific variables EnableJITVars(uint64_t parser_id)186 void EnableJITVars(uint64_t parser_id) { 187 m_jit_vars.insert(std::make_pair(parser_id, JITVars())); 188 } 189 190 /// Deallocate JIT-specific variables DisableJITVars(uint64_t parser_id)191 void DisableJITVars(uint64_t parser_id) { m_jit_vars.erase(parser_id); } 192 GetJITVars(uint64_t parser_id)193 JITVars *GetJITVars(uint64_t parser_id) { 194 JITVarMap::iterator i = m_jit_vars.find(parser_id); 195 196 if (i == m_jit_vars.end()) 197 return nullptr; 198 else 199 return &i->second; 200 } 201 202 TypeFromUser GetTypeFromUser(); 203 204 /// Members 205 ClangExpressionVariable(const ClangExpressionVariable &) = delete; 206 const ClangExpressionVariable & 207 operator=(const ClangExpressionVariable &) = delete; 208 }; 209 210 } // namespace lldb_private 211 212 #endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONVARIABLE_H 213