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