1 //===-- LLVMUserExpression.cpp --------------------------------------------===// 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 #include "lldb/Expression/LLVMUserExpression.h" 10 #include "lldb/Core/Module.h" 11 #include "lldb/Expression/DiagnosticManager.h" 12 #include "lldb/Expression/ExpressionVariable.h" 13 #include "lldb/Expression/IRExecutionUnit.h" 14 #include "lldb/Expression/IRInterpreter.h" 15 #include "lldb/Expression/Materializer.h" 16 #include "lldb/Host/HostInfo.h" 17 #include "lldb/Symbol/Block.h" 18 #include "lldb/Symbol/Function.h" 19 #include "lldb/Symbol/ObjectFile.h" 20 #include "lldb/Symbol/SymbolVendor.h" 21 #include "lldb/Symbol/Type.h" 22 #include "lldb/Symbol/VariableList.h" 23 #include "lldb/Target/ABI.h" 24 #include "lldb/Target/ExecutionContext.h" 25 #include "lldb/Target/Process.h" 26 #include "lldb/Target/StackFrame.h" 27 #include "lldb/Target/Target.h" 28 #include "lldb/Target/ThreadPlan.h" 29 #include "lldb/Target/ThreadPlanCallUserExpression.h" 30 #include "lldb/Utility/ConstString.h" 31 #include "lldb/Utility/ErrorMessages.h" 32 #include "lldb/Utility/LLDBLog.h" 33 #include "lldb/Utility/Log.h" 34 #include "lldb/Utility/StreamString.h" 35 #include "lldb/ValueObject/ValueObjectConstResult.h" 36 37 using namespace lldb; 38 using namespace lldb_private; 39 40 char LLVMUserExpression::ID; 41 42 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope, 43 llvm::StringRef expr, 44 llvm::StringRef prefix, 45 SourceLanguage language, 46 ResultType desired_type, 47 const EvaluateExpressionOptions &options) 48 : UserExpression(exe_scope, expr, prefix, language, desired_type, options), 49 m_stack_frame_bottom(LLDB_INVALID_ADDRESS), 50 m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false), 51 m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(), 52 m_materializer_up(), m_jit_module_wp(), m_target(nullptr), 53 m_can_interpret(false), m_materialized_address(LLDB_INVALID_ADDRESS) {} 54 55 LLVMUserExpression::~LLVMUserExpression() { 56 if (m_target) { 57 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 58 if (jit_module_sp) 59 m_target->GetImages().Remove(jit_module_sp); 60 } 61 } 62 63 lldb::ExpressionResults 64 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager, 65 ExecutionContext &exe_ctx, 66 const EvaluateExpressionOptions &options, 67 lldb::UserExpressionSP &shared_ptr_to_me, 68 lldb::ExpressionVariableSP &result) { 69 // The expression log is quite verbose, and if you're just tracking the 70 // execution of the expression, it's quite convenient to have these logs come 71 // out with the STEP log as well. 72 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step)); 73 74 if (m_jit_start_addr == LLDB_INVALID_ADDRESS && !m_can_interpret) { 75 diagnostic_manager.PutString( 76 lldb::eSeverityError, 77 "Expression can't be run, because there is no JIT compiled function"); 78 return lldb::eExpressionSetupError; 79 } 80 81 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS; 82 83 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx, 84 struct_address)) { 85 diagnostic_manager.Printf( 86 lldb::eSeverityError, 87 "errored out in %s, couldn't PrepareToExecuteJITExpression", 88 __FUNCTION__); 89 return lldb::eExpressionSetupError; 90 } 91 92 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS; 93 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS; 94 95 if (m_can_interpret) { 96 llvm::Module *module = m_execution_unit_sp->GetModule(); 97 llvm::Function *function = m_execution_unit_sp->GetFunction(); 98 99 if (!module || !function) { 100 diagnostic_manager.PutString( 101 lldb::eSeverityError, "supposed to interpret, but nothing is there"); 102 return lldb::eExpressionSetupError; 103 } 104 105 Status interpreter_error; 106 107 std::vector<lldb::addr_t> args; 108 109 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 110 diagnostic_manager.Printf(lldb::eSeverityError, 111 "errored out in %s, couldn't AddArguments", 112 __FUNCTION__); 113 return lldb::eExpressionSetupError; 114 } 115 116 function_stack_bottom = m_stack_frame_bottom; 117 function_stack_top = m_stack_frame_top; 118 119 IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp, 120 interpreter_error, function_stack_bottom, 121 function_stack_top, exe_ctx, options.GetTimeout()); 122 123 if (!interpreter_error.Success()) { 124 diagnostic_manager.Printf(lldb::eSeverityError, 125 "supposed to interpret, but failed: %s", 126 interpreter_error.AsCString()); 127 return lldb::eExpressionDiscarded; 128 } 129 } else { 130 if (!exe_ctx.HasThreadScope()) { 131 diagnostic_manager.Printf(lldb::eSeverityError, 132 "%s called with no thread selected", 133 __FUNCTION__); 134 return lldb::eExpressionSetupError; 135 } 136 137 // Store away the thread ID for error reporting, in case it exits 138 // during execution: 139 lldb::tid_t expr_thread_id = exe_ctx.GetThreadRef().GetID(); 140 141 Address wrapper_address(m_jit_start_addr); 142 143 std::vector<lldb::addr_t> args; 144 145 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 146 diagnostic_manager.Printf(lldb::eSeverityError, 147 "errored out in %s, couldn't AddArguments", 148 __FUNCTION__); 149 return lldb::eExpressionSetupError; 150 } 151 152 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression( 153 exe_ctx.GetThreadRef(), wrapper_address, args, options, 154 shared_ptr_to_me)); 155 156 StreamString ss; 157 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) { 158 diagnostic_manager.PutString(lldb::eSeverityError, ss.GetString()); 159 return lldb::eExpressionSetupError; 160 } 161 162 ThreadPlanCallUserExpression *user_expression_plan = 163 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get()); 164 165 lldb::addr_t function_stack_pointer = 166 user_expression_plan->GetFunctionStackPointer(); 167 168 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize(); 169 function_stack_top = function_stack_pointer; 170 171 LLDB_LOGF(log, 172 "-- [UserExpression::Execute] Execution of expression begins --"); 173 174 if (exe_ctx.GetProcessPtr()) 175 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); 176 177 lldb::ExpressionResults execution_result = 178 exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options, 179 diagnostic_manager); 180 181 if (exe_ctx.GetProcessPtr()) 182 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); 183 184 LLDB_LOGF(log, "-- [UserExpression::Execute] Execution of expression " 185 "completed --"); 186 187 if (execution_result == lldb::eExpressionInterrupted || 188 execution_result == lldb::eExpressionHitBreakpoint) { 189 const char *error_desc = nullptr; 190 const char *explanation = execution_result == lldb::eExpressionInterrupted 191 ? "was interrupted" 192 : "hit a breakpoint"; 193 194 if (user_expression_plan) { 195 if (auto real_stop_info_sp = user_expression_plan->GetRealStopInfo()) 196 error_desc = real_stop_info_sp->GetDescription(); 197 } 198 199 if (error_desc) 200 diagnostic_manager.Printf(lldb::eSeverityError, 201 "Expression execution %s: %s.", explanation, 202 error_desc); 203 else 204 diagnostic_manager.Printf(lldb::eSeverityError, 205 "Expression execution %s.", explanation); 206 207 if ((execution_result == lldb::eExpressionInterrupted && 208 options.DoesUnwindOnError()) || 209 (execution_result == lldb::eExpressionHitBreakpoint && 210 options.DoesIgnoreBreakpoints())) 211 diagnostic_manager.AppendMessageToDiagnostic( 212 "The process has been returned to the state before expression " 213 "evaluation."); 214 else { 215 if (execution_result == lldb::eExpressionHitBreakpoint) 216 user_expression_plan->TransferExpressionOwnership(); 217 diagnostic_manager.AppendMessageToDiagnostic( 218 "The process has been left at the point where it was " 219 "interrupted, use \"thread return -x\" to return to the state " 220 "before expression evaluation."); 221 } 222 223 return execution_result; 224 } 225 226 if (execution_result == lldb::eExpressionStoppedForDebug) { 227 diagnostic_manager.PutString( 228 lldb::eSeverityInfo, 229 "Expression execution was halted at the first instruction of the " 230 "expression function because \"debug\" was requested.\n" 231 "Use \"thread return -x\" to return to the state before expression " 232 "evaluation."); 233 return execution_result; 234 } 235 236 if (execution_result == lldb::eExpressionThreadVanished) { 237 diagnostic_manager.Printf(lldb::eSeverityError, 238 "Couldn't execute expression: the thread on " 239 "which the expression was being run (0x%" PRIx64 240 ") exited during its execution.", 241 expr_thread_id); 242 return execution_result; 243 } 244 245 if (execution_result != lldb::eExpressionCompleted) { 246 diagnostic_manager.Printf(lldb::eSeverityError, 247 "Couldn't execute expression: result was %s", 248 toString(execution_result).c_str()); 249 return execution_result; 250 } 251 } 252 253 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result, 254 function_stack_bottom, function_stack_top)) { 255 return lldb::eExpressionCompleted; 256 } 257 258 return lldb::eExpressionResultUnavailable; 259 } 260 261 bool LLVMUserExpression::FinalizeJITExecution( 262 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 263 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 264 lldb::addr_t function_stack_top) { 265 Log *log = GetLog(LLDBLog::Expressions); 266 267 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing " 268 "after execution --"); 269 270 if (!m_dematerializer_sp) { 271 diagnostic_manager.Printf(lldb::eSeverityError, 272 "Couldn't apply expression side effects : no " 273 "dematerializer is present"); 274 return false; 275 } 276 277 Status dematerialize_error; 278 279 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 280 function_stack_top); 281 282 if (!dematerialize_error.Success()) { 283 diagnostic_manager.Printf(lldb::eSeverityError, 284 "Couldn't apply expression side effects : %s", 285 dematerialize_error.AsCString("unknown error")); 286 return false; 287 } 288 289 result = 290 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 291 292 if (result) 293 result->TransferAddress(); 294 295 m_dematerializer_sp.reset(); 296 297 return true; 298 } 299 300 bool LLVMUserExpression::PrepareToExecuteJITExpression( 301 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 302 lldb::addr_t &struct_address) { 303 lldb::TargetSP target; 304 lldb::ProcessSP process; 305 lldb::StackFrameSP frame; 306 307 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 308 diagnostic_manager.PutString( 309 lldb::eSeverityError, 310 "The context has changed before we could JIT the expression!"); 311 return false; 312 } 313 314 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 315 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 316 Status alloc_error; 317 318 IRMemoryMap::AllocationPolicy policy = 319 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 320 : IRMemoryMap::eAllocationPolicyMirror; 321 322 const bool zero_memory = false; 323 324 m_materialized_address = m_execution_unit_sp->Malloc( 325 m_materializer_up->GetStructByteSize(), 326 m_materializer_up->GetStructAlignment(), 327 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 328 zero_memory, alloc_error); 329 330 if (!alloc_error.Success()) { 331 diagnostic_manager.Printf( 332 lldb::eSeverityError, 333 "Couldn't allocate space for materialized struct: %s", 334 alloc_error.AsCString()); 335 return false; 336 } 337 } 338 339 struct_address = m_materialized_address; 340 341 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 342 Status alloc_error; 343 344 size_t stack_frame_size = target->GetExprAllocSize(); 345 if (stack_frame_size == 0) { 346 ABISP abi_sp; 347 if (process && (abi_sp = process->GetABI())) 348 stack_frame_size = abi_sp->GetStackFrameSize(); 349 else 350 stack_frame_size = 512 * 1024; 351 } 352 353 const bool zero_memory = false; 354 355 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 356 stack_frame_size, 8, 357 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 358 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 359 360 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 361 362 if (!alloc_error.Success()) { 363 diagnostic_manager.Printf( 364 lldb::eSeverityError, 365 "Couldn't allocate space for the stack frame: %s", 366 alloc_error.AsCString()); 367 return false; 368 } 369 } 370 371 Status materialize_error; 372 373 m_dematerializer_sp = m_materializer_up->Materialize( 374 frame, *m_execution_unit_sp, struct_address, materialize_error); 375 376 if (!materialize_error.Success()) { 377 diagnostic_manager.Printf(lldb::eSeverityError, 378 "Couldn't materialize: %s", 379 materialize_error.AsCString()); 380 return false; 381 } 382 } 383 return true; 384 } 385 386