1 //===-- LLVMUserExpression.cpp ----------------------------------*- 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 10 #include "lldb/Expression/LLVMUserExpression.h" 11 #include "lldb/Core/Module.h" 12 #include "lldb/Core/StreamFile.h" 13 #include "lldb/Core/ValueObjectConstResult.h" 14 #include "lldb/Expression/DiagnosticManager.h" 15 #include "lldb/Expression/IRExecutionUnit.h" 16 #include "lldb/Expression/IRInterpreter.h" 17 #include "lldb/Expression/Materializer.h" 18 #include "lldb/Host/HostInfo.h" 19 #include "lldb/Symbol/Block.h" 20 #include "lldb/Symbol/ClangASTContext.h" 21 #include "lldb/Symbol/ClangExternalASTSourceCommon.h" 22 #include "lldb/Symbol/Function.h" 23 #include "lldb/Symbol/ObjectFile.h" 24 #include "lldb/Symbol/SymbolVendor.h" 25 #include "lldb/Symbol/Type.h" 26 #include "lldb/Symbol/VariableList.h" 27 #include "lldb/Target/ExecutionContext.h" 28 #include "lldb/Target/Process.h" 29 #include "lldb/Target/StackFrame.h" 30 #include "lldb/Target/Target.h" 31 #include "lldb/Target/ThreadPlan.h" 32 #include "lldb/Target/ThreadPlanCallUserExpression.h" 33 #include "lldb/Utility/ConstString.h" 34 #include "lldb/Utility/Log.h" 35 #include "lldb/Utility/StreamString.h" 36 37 using namespace lldb_private; 38 39 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope, 40 llvm::StringRef expr, 41 llvm::StringRef prefix, 42 lldb::LanguageType language, 43 ResultType desired_type, 44 const EvaluateExpressionOptions &options, 45 ExpressionKind kind) 46 : UserExpression(exe_scope, expr, prefix, language, desired_type, options, 47 kind), 48 m_stack_frame_bottom(LLDB_INVALID_ADDRESS), 49 m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false), 50 m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(), 51 m_materializer_up(), m_jit_module_wp(), m_enforce_valid_object(true), 52 m_in_cplusplus_method(false), m_in_objectivec_method(false), 53 m_in_static_method(false), m_needs_object_ptr(false), m_target(nullptr), 54 m_can_interpret(false), m_materialized_address(LLDB_INVALID_ADDRESS) {} 55 56 LLVMUserExpression::~LLVMUserExpression() { 57 if (m_target) { 58 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 59 if (jit_module_sp) 60 m_target->GetImages().Remove(jit_module_sp); 61 } 62 } 63 64 lldb::ExpressionResults 65 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager, 66 ExecutionContext &exe_ctx, 67 const EvaluateExpressionOptions &options, 68 lldb::UserExpressionSP &shared_ptr_to_me, 69 lldb::ExpressionVariableSP &result) { 70 // The expression log is quite verbose, and if you're just tracking the 71 // execution of the expression, it's quite convenient to have these logs come 72 // out with the STEP log as well. 73 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | 74 LIBLLDB_LOG_STEP)); 75 76 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 77 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS; 78 79 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx, 80 struct_address)) { 81 diagnostic_manager.Printf( 82 eDiagnosticSeverityError, 83 "errored out in %s, couldn't PrepareToExecuteJITExpression", 84 __FUNCTION__); 85 return lldb::eExpressionSetupError; 86 } 87 88 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS; 89 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS; 90 91 if (m_can_interpret) { 92 llvm::Module *module = m_execution_unit_sp->GetModule(); 93 llvm::Function *function = m_execution_unit_sp->GetFunction(); 94 95 if (!module || !function) { 96 diagnostic_manager.PutString( 97 eDiagnosticSeverityError, 98 "supposed to interpret, but nothing is there"); 99 return lldb::eExpressionSetupError; 100 } 101 102 Status interpreter_error; 103 104 std::vector<lldb::addr_t> args; 105 106 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 107 diagnostic_manager.Printf(eDiagnosticSeverityError, 108 "errored out in %s, couldn't AddArguments", 109 __FUNCTION__); 110 return lldb::eExpressionSetupError; 111 } 112 113 function_stack_bottom = m_stack_frame_bottom; 114 function_stack_top = m_stack_frame_top; 115 116 IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp, 117 interpreter_error, function_stack_bottom, 118 function_stack_top, exe_ctx); 119 120 if (!interpreter_error.Success()) { 121 diagnostic_manager.Printf(eDiagnosticSeverityError, 122 "supposed to interpret, but failed: %s", 123 interpreter_error.AsCString()); 124 return lldb::eExpressionDiscarded; 125 } 126 } else { 127 if (!exe_ctx.HasThreadScope()) { 128 diagnostic_manager.Printf(eDiagnosticSeverityError, 129 "%s called with no thread selected", 130 __FUNCTION__); 131 return lldb::eExpressionSetupError; 132 } 133 134 Address wrapper_address(m_jit_start_addr); 135 136 std::vector<lldb::addr_t> args; 137 138 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 139 diagnostic_manager.Printf(eDiagnosticSeverityError, 140 "errored out in %s, couldn't AddArguments", 141 __FUNCTION__); 142 return lldb::eExpressionSetupError; 143 } 144 145 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression( 146 exe_ctx.GetThreadRef(), wrapper_address, args, options, 147 shared_ptr_to_me)); 148 149 StreamString ss; 150 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) { 151 diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString()); 152 return lldb::eExpressionSetupError; 153 } 154 155 ThreadPlanCallUserExpression *user_expression_plan = 156 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get()); 157 158 lldb::addr_t function_stack_pointer = 159 user_expression_plan->GetFunctionStackPointer(); 160 161 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize(); 162 function_stack_top = function_stack_pointer; 163 164 if (log) 165 log->Printf( 166 "-- [UserExpression::Execute] Execution of expression begins --"); 167 168 if (exe_ctx.GetProcessPtr()) 169 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); 170 171 lldb::ExpressionResults execution_result = 172 exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options, 173 diagnostic_manager); 174 175 if (exe_ctx.GetProcessPtr()) 176 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); 177 178 if (log) 179 log->Printf("-- [UserExpression::Execute] Execution of expression " 180 "completed --"); 181 182 if (execution_result == lldb::eExpressionInterrupted || 183 execution_result == lldb::eExpressionHitBreakpoint) { 184 const char *error_desc = nullptr; 185 186 if (call_plan_sp) { 187 lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo(); 188 if (real_stop_info_sp) 189 error_desc = real_stop_info_sp->GetDescription(); 190 } 191 if (error_desc) 192 diagnostic_manager.Printf(eDiagnosticSeverityError, 193 "Execution was interrupted, reason: %s.", 194 error_desc); 195 else 196 diagnostic_manager.PutString(eDiagnosticSeverityError, 197 "Execution was interrupted."); 198 199 if ((execution_result == lldb::eExpressionInterrupted && 200 options.DoesUnwindOnError()) || 201 (execution_result == lldb::eExpressionHitBreakpoint && 202 options.DoesIgnoreBreakpoints())) 203 diagnostic_manager.AppendMessageToDiagnostic( 204 "The process has been returned to the state before expression " 205 "evaluation."); 206 else { 207 if (execution_result == lldb::eExpressionHitBreakpoint) 208 user_expression_plan->TransferExpressionOwnership(); 209 diagnostic_manager.AppendMessageToDiagnostic( 210 "The process has been left at the point where it was " 211 "interrupted, " 212 "use \"thread return -x\" to return to the state before " 213 "expression evaluation."); 214 } 215 216 return execution_result; 217 } else if (execution_result == lldb::eExpressionStoppedForDebug) { 218 diagnostic_manager.PutString( 219 eDiagnosticSeverityRemark, 220 "Execution was halted at the first instruction of the expression " 221 "function because \"debug\" was requested.\n" 222 "Use \"thread return -x\" to return to the state before expression " 223 "evaluation."); 224 return execution_result; 225 } else if (execution_result != lldb::eExpressionCompleted) { 226 diagnostic_manager.Printf( 227 eDiagnosticSeverityError, 228 "Couldn't execute function; result was %s", 229 Process::ExecutionResultAsCString(execution_result)); 230 return execution_result; 231 } 232 } 233 234 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result, 235 function_stack_bottom, function_stack_top)) { 236 return lldb::eExpressionCompleted; 237 } else { 238 return lldb::eExpressionResultUnavailable; 239 } 240 } else { 241 diagnostic_manager.PutString( 242 eDiagnosticSeverityError, 243 "Expression can't be run, because there is no JIT compiled function"); 244 return lldb::eExpressionSetupError; 245 } 246 } 247 248 bool LLVMUserExpression::FinalizeJITExecution( 249 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 250 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 251 lldb::addr_t function_stack_top) { 252 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)); 253 254 if (log) 255 log->Printf("-- [UserExpression::FinalizeJITExecution] Dematerializing " 256 "after execution --"); 257 258 if (!m_dematerializer_sp) { 259 diagnostic_manager.Printf(eDiagnosticSeverityError, 260 "Couldn't apply expression side effects : no " 261 "dematerializer is present"); 262 return false; 263 } 264 265 Status dematerialize_error; 266 267 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 268 function_stack_top); 269 270 if (!dematerialize_error.Success()) { 271 diagnostic_manager.Printf(eDiagnosticSeverityError, 272 "Couldn't apply expression side effects : %s", 273 dematerialize_error.AsCString("unknown error")); 274 return false; 275 } 276 277 result = 278 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 279 280 if (result) 281 result->TransferAddress(); 282 283 m_dematerializer_sp.reset(); 284 285 return true; 286 } 287 288 bool LLVMUserExpression::PrepareToExecuteJITExpression( 289 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 290 lldb::addr_t &struct_address) { 291 lldb::TargetSP target; 292 lldb::ProcessSP process; 293 lldb::StackFrameSP frame; 294 295 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 296 diagnostic_manager.PutString( 297 eDiagnosticSeverityError, 298 "The context has changed before we could JIT the expression!"); 299 return false; 300 } 301 302 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 303 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 304 Status alloc_error; 305 306 IRMemoryMap::AllocationPolicy policy = 307 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 308 : IRMemoryMap::eAllocationPolicyMirror; 309 310 const bool zero_memory = false; 311 312 m_materialized_address = m_execution_unit_sp->Malloc( 313 m_materializer_up->GetStructByteSize(), 314 m_materializer_up->GetStructAlignment(), 315 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 316 zero_memory, alloc_error); 317 318 if (!alloc_error.Success()) { 319 diagnostic_manager.Printf( 320 eDiagnosticSeverityError, 321 "Couldn't allocate space for materialized struct: %s", 322 alloc_error.AsCString()); 323 return false; 324 } 325 } 326 327 struct_address = m_materialized_address; 328 329 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 330 Status alloc_error; 331 332 const size_t stack_frame_size = 512 * 1024; 333 334 const bool zero_memory = false; 335 336 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 337 stack_frame_size, 8, 338 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 339 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 340 341 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 342 343 if (!alloc_error.Success()) { 344 diagnostic_manager.Printf( 345 eDiagnosticSeverityError, 346 "Couldn't allocate space for the stack frame: %s", 347 alloc_error.AsCString()); 348 return false; 349 } 350 } 351 352 Status materialize_error; 353 354 m_dematerializer_sp = m_materializer_up->Materialize( 355 frame, *m_execution_unit_sp, struct_address, materialize_error); 356 357 if (!materialize_error.Success()) { 358 diagnostic_manager.Printf(eDiagnosticSeverityError, 359 "Couldn't materialize: %s", 360 materialize_error.AsCString()); 361 return false; 362 } 363 } 364 return true; 365 } 366 367 lldb::ModuleSP LLVMUserExpression::GetJITModule() { 368 if (m_execution_unit_sp) 369 return m_execution_unit_sp->GetJITModule(); 370 return lldb::ModuleSP(); 371 } 372