1 //===-- LanguageRuntime.h ---------------------------------------------------*- 2 // C++ -*-===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLDB_TARGET_LANGUAGERUNTIME_H 11 #define LLDB_TARGET_LANGUAGERUNTIME_H 12 13 #include "lldb/Breakpoint/BreakpointResolver.h" 14 #include "lldb/Breakpoint/BreakpointResolverName.h" 15 #include "lldb/Core/PluginInterface.h" 16 #include "lldb/Core/Value.h" 17 #include "lldb/Core/ValueObject.h" 18 #include "lldb/Expression/LLVMUserExpression.h" 19 #include "lldb/Symbol/DeclVendor.h" 20 #include "lldb/Target/ExecutionContextScope.h" 21 #include "lldb/Target/Runtime.h" 22 #include "lldb/lldb-private.h" 23 #include "lldb/lldb-public.h" 24 #include <optional> 25 26 namespace lldb_private { 27 28 class ExceptionSearchFilter : public SearchFilter { 29 public: 30 ExceptionSearchFilter(const lldb::TargetSP &target_sp, 31 lldb::LanguageType language, 32 bool update_module_list = true); 33 34 ~ExceptionSearchFilter() override = default; 35 36 bool ModulePasses(const lldb::ModuleSP &module_sp) override; 37 38 bool ModulePasses(const FileSpec &spec) override; 39 40 void Search(Searcher &searcher) override; 41 42 void GetDescription(Stream *s) override; 43 44 static SearchFilter * 45 CreateFromStructuredData(Target &target, 46 const StructuredData::Dictionary &data_dict, 47 Status &error); 48 49 StructuredData::ObjectSP SerializeToStructuredData() override; 50 51 protected: 52 lldb::LanguageType m_language; 53 LanguageRuntime *m_language_runtime; 54 lldb::SearchFilterSP m_filter_sp; 55 56 lldb::SearchFilterSP DoCreateCopy() override; 57 58 void UpdateModuleListIfNeeded(); 59 }; 60 61 class LanguageRuntime : public Runtime, public PluginInterface { 62 public: 63 static LanguageRuntime *FindPlugin(Process *process, 64 lldb::LanguageType language); 65 66 static void InitializeCommands(CommandObject *parent); 67 68 virtual lldb::LanguageType GetLanguageType() const = 0; 69 70 /// Return the preferred language runtime instance, which in most cases will 71 /// be the current instance. GetPreferredLanguageRuntime(ValueObject & in_value)72 virtual LanguageRuntime *GetPreferredLanguageRuntime(ValueObject &in_value) { 73 return nullptr; 74 } 75 76 virtual llvm::Error GetObjectDescription(Stream &str, 77 ValueObject &object) = 0; 78 79 virtual llvm::Error 80 GetObjectDescription(Stream &str, Value &value, 81 ExecutionContextScope *exe_scope) = 0; 82 83 struct VTableInfo { 84 Address addr; /// Address of the vtable's virtual function table 85 Symbol *symbol; /// The vtable symbol from the symbol table 86 }; 87 /// Get the vtable information for a given value. 88 /// 89 /// \param[in] in_value 90 /// The value object to try and extract the VTableInfo from. 91 /// 92 /// \param[in] check_type 93 /// If true, the compiler type of \a in_value will be checked to see if 94 /// it is an instance to, or pointer or reference to a class or struct 95 /// that has a vtable. If the type doesn't meet the requirements, an 96 /// error will be returned explaining why the type isn't suitable. 97 /// 98 /// \return 99 /// An error if anything goes wrong while trying to extract the vtable 100 /// or if \a check_type is true and the type doesn't have a vtable. GetVTableInfo(ValueObject & in_value,bool check_type)101 virtual llvm::Expected<VTableInfo> GetVTableInfo(ValueObject &in_value, 102 bool check_type) { 103 return llvm::createStringError( 104 std::errc::invalid_argument, 105 "language doesn't support getting vtable information"); 106 } 107 108 // this call should return true if it could set the name and/or the type 109 virtual bool GetDynamicTypeAndAddress(ValueObject &in_value, 110 lldb::DynamicValueType use_dynamic, 111 TypeAndOrName &class_type_or_name, 112 Address &address, 113 Value::ValueType &value_type) = 0; 114 115 // This call should return a CompilerType given a generic type name and an 116 // ExecutionContextScope in which one can actually fetch any specialization 117 // information required. GetConcreteType(ExecutionContextScope * exe_scope,ConstString abstract_type_name)118 virtual CompilerType GetConcreteType(ExecutionContextScope *exe_scope, 119 ConstString abstract_type_name) { 120 return CompilerType(); 121 } 122 123 // This should be a fast test to determine whether it is likely that this 124 // value would have a dynamic type. 125 virtual bool CouldHaveDynamicValue(ValueObject &in_value) = 0; 126 127 // The contract for GetDynamicTypeAndAddress() is to return a "bare-bones" 128 // dynamic type For instance, given a Base* pointer, 129 // GetDynamicTypeAndAddress() will return the type of Derived, not Derived*. 130 // The job of this API is to correct this misalignment between the static 131 // type and the discovered dynamic type 132 virtual TypeAndOrName FixUpDynamicType(const TypeAndOrName &type_and_or_name, 133 ValueObject &static_value) = 0; 134 SetExceptionBreakpoints()135 virtual void SetExceptionBreakpoints() {} 136 ClearExceptionBreakpoints()137 virtual void ClearExceptionBreakpoints() {} 138 ExceptionBreakpointsAreSet()139 virtual bool ExceptionBreakpointsAreSet() { return false; } 140 ExceptionBreakpointsExplainStop(lldb::StopInfoSP stop_reason)141 virtual bool ExceptionBreakpointsExplainStop(lldb::StopInfoSP stop_reason) { 142 return false; 143 } 144 145 static lldb::BreakpointSP 146 CreateExceptionBreakpoint(Target &target, lldb::LanguageType language, 147 bool catch_bp, bool throw_bp, 148 bool is_internal = false); 149 150 static lldb::BreakpointPreconditionSP 151 GetExceptionPrecondition(lldb::LanguageType language, bool throw_bp); 152 GetExceptionObjectForThread(lldb::ThreadSP thread_sp)153 virtual lldb::ValueObjectSP GetExceptionObjectForThread( 154 lldb::ThreadSP thread_sp) { 155 return lldb::ValueObjectSP(); 156 } 157 GetBacktraceThreadFromException(lldb::ValueObjectSP thread_sp)158 virtual lldb::ThreadSP GetBacktraceThreadFromException( 159 lldb::ValueObjectSP thread_sp) { 160 return lldb::ThreadSP(); 161 } 162 GetDeclVendor()163 virtual DeclVendor *GetDeclVendor() { return nullptr; } 164 165 virtual lldb::BreakpointResolverSP 166 CreateExceptionResolver(const lldb::BreakpointSP &bkpt, 167 bool catch_bp, bool throw_bp) = 0; 168 CreateExceptionSearchFilter()169 virtual lldb::SearchFilterSP CreateExceptionSearchFilter() { 170 return m_process->GetTarget().GetSearchFilterForModule(nullptr); 171 } 172 173 virtual std::optional<uint64_t> GetTypeBitSize(const CompilerType & compiler_type)174 GetTypeBitSize(const CompilerType &compiler_type) { 175 return {}; 176 } 177 SymbolsDidLoad(const ModuleList & module_list)178 virtual void SymbolsDidLoad(const ModuleList &module_list) {} 179 180 virtual lldb::ThreadPlanSP GetStepThroughTrampolinePlan(Thread &thread, 181 bool stop_others) = 0; 182 183 /// Identify whether a name is a runtime value that should not be hidden by 184 /// from the user interface. IsAllowedRuntimeValue(ConstString name)185 virtual bool IsAllowedRuntimeValue(ConstString name) { return false; } 186 GetRuntimeType(CompilerType base_type)187 virtual std::optional<CompilerType> GetRuntimeType(CompilerType base_type) { 188 return std::nullopt; 189 } 190 ModulesDidLoad(const ModuleList & module_list)191 void ModulesDidLoad(const ModuleList &module_list) override {} 192 193 // Called by ClangExpressionParser::PrepareForExecution to query for any 194 // custom LLVM IR passes that need to be run before an expression is 195 // assembled and run. GetIRPasses(LLVMUserExpression::IRPasses & custom_passes)196 virtual bool GetIRPasses(LLVMUserExpression::IRPasses &custom_passes) { 197 return false; 198 } 199 200 // Given the name of a runtime symbol (e.g. in Objective-C, an ivar offset 201 // symbol), try to determine from the runtime what the value of that symbol 202 // would be. Useful when the underlying binary is stripped. LookupRuntimeSymbol(ConstString name)203 virtual lldb::addr_t LookupRuntimeSymbol(ConstString name) { 204 return LLDB_INVALID_ADDRESS; 205 } 206 isA(const void * ClassID)207 virtual bool isA(const void *ClassID) const { return ClassID == &ID; } 208 static char ID; 209 210 /// A language runtime may be able to provide a special UnwindPlan for 211 /// the frame represented by the register contents \a regctx when that 212 /// frame is not following the normal ABI conventions. 213 /// Instead of using the normal UnwindPlan for the function, we will use 214 /// this special UnwindPlan for this one backtrace. 215 /// One example of this would be a language that has asynchronous functions, 216 /// functions that may not be currently-executing, while waiting on other 217 /// asynchronous calls they made, but are part of a logical backtrace that 218 /// we want to show the developer because that's how they think of the 219 /// program flow. 220 /// 221 /// \param[in] thread 222 /// The thread that the unwind is happening on. 223 /// 224 /// \param[in] regctx 225 /// The RegisterContext for the frame we need to create an UnwindPlan. 226 /// We don't yet have a StackFrame when we're selecting the UnwindPlan. 227 /// 228 /// \param[out] behaves_like_zeroth_frame 229 /// With normal ABI calls, all stack frames except the zeroth frame need 230 /// to have the return-pc value backed up by 1 for symbolication purposes. 231 /// For these LanguageRuntime unwind plans, they may not follow normal ABI 232 /// calling conventions and the return pc may need to be symbolicated 233 /// as-is. 234 /// 235 /// \return 236 /// Returns an UnwindPlan to find the caller frame if it should be used, 237 /// instead of the UnwindPlan that would normally be used for this 238 /// function. 239 static lldb::UnwindPlanSP 240 GetRuntimeUnwindPlan(lldb_private::Thread &thread, 241 lldb_private::RegisterContext *regctx, 242 bool &behaves_like_zeroth_frame); 243 244 protected: 245 // The static GetRuntimeUnwindPlan method above is only implemented in the 246 // base class; subclasses may override this protected member if they can 247 // provide one of these UnwindPlans. 248 virtual lldb::UnwindPlanSP GetRuntimeUnwindPlan(lldb::ProcessSP process_sp,lldb_private::RegisterContext * regctx,bool & behaves_like_zeroth_frame)249 GetRuntimeUnwindPlan(lldb::ProcessSP process_sp, 250 lldb_private::RegisterContext *regctx, 251 bool &behaves_like_zeroth_frame) { 252 return lldb::UnwindPlanSP(); 253 } 254 255 LanguageRuntime(Process *process); 256 }; 257 258 } // namespace lldb_private 259 260 #endif // LLDB_TARGET_LANGUAGERUNTIME_H 261