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/ExecutionContext.h" 27 #include "lldb/Target/Process.h" 28 #include "lldb/Target/StackFrame.h" 29 #include "lldb/Target/Target.h" 30 #include "lldb/Target/ThreadPlan.h" 31 #include "lldb/Target/ThreadPlanCallUserExpression.h" 32 #include "lldb/Utility/ConstString.h" 33 #include "lldb/Utility/LLDBLog.h" 34 #include "lldb/Utility/Log.h" 35 #include "lldb/Utility/StreamString.h" 36 37 using namespace lldb_private; 38 39 char LLVMUserExpression::ID; 40 41 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope, 42 llvm::StringRef expr, 43 llvm::StringRef prefix, 44 lldb::LanguageType language, 45 ResultType desired_type, 46 const EvaluateExpressionOptions &options) 47 : UserExpression(exe_scope, expr, prefix, language, desired_type, options), 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_can_interpret(false), 52 m_materialized_address(LLDB_INVALID_ADDRESS) {} 53 54 LLVMUserExpression::~LLVMUserExpression() { 55 if (m_target) { 56 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 57 if (jit_module_sp) 58 m_target->GetImages().Remove(jit_module_sp); 59 } 60 } 61 62 lldb::ExpressionResults 63 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager, 64 ExecutionContext &exe_ctx, 65 const EvaluateExpressionOptions &options, 66 lldb::UserExpressionSP &shared_ptr_to_me, 67 lldb::ExpressionVariableSP &result) { 68 // The expression log is quite verbose, and if you're just tracking the 69 // execution of the expression, it's quite convenient to have these logs come 70 // out with the STEP log as well. 71 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step)); 72 73 if (m_jit_start_addr == LLDB_INVALID_ADDRESS && !m_can_interpret) { 74 diagnostic_manager.PutString( 75 eDiagnosticSeverityError, 76 "Expression can't be run, because there is no JIT compiled function"); 77 return lldb::eExpressionSetupError; 78 } 79 80 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS; 81 82 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx, 83 struct_address)) { 84 diagnostic_manager.Printf( 85 eDiagnosticSeverityError, 86 "errored out in %s, couldn't PrepareToExecuteJITExpression", 87 __FUNCTION__); 88 return lldb::eExpressionSetupError; 89 } 90 91 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS; 92 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS; 93 94 if (m_can_interpret) { 95 llvm::Module *module = m_execution_unit_sp->GetModule(); 96 llvm::Function *function = m_execution_unit_sp->GetFunction(); 97 98 if (!module || !function) { 99 diagnostic_manager.PutString( 100 eDiagnosticSeverityError, 101 "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(eDiagnosticSeverityError, 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); 122 123 if (!interpreter_error.Success()) { 124 diagnostic_manager.Printf(eDiagnosticSeverityError, 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(eDiagnosticSeverityError, 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(eDiagnosticSeverityError, 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(eDiagnosticSeverityError, 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; 190 191 if (user_expression_plan) { 192 if (auto real_stop_info_sp = user_expression_plan->GetRealStopInfo()) 193 error_desc = real_stop_info_sp->GetDescription(); 194 } 195 if (error_desc) 196 diagnostic_manager.Printf(eDiagnosticSeverityError, 197 "Execution was interrupted, reason: %s.", 198 error_desc); 199 else 200 diagnostic_manager.PutString(eDiagnosticSeverityError, 201 "Execution was interrupted."); 202 203 if ((execution_result == lldb::eExpressionInterrupted && 204 options.DoesUnwindOnError()) || 205 (execution_result == lldb::eExpressionHitBreakpoint && 206 options.DoesIgnoreBreakpoints())) 207 diagnostic_manager.AppendMessageToDiagnostic( 208 "The process has been returned to the state before expression " 209 "evaluation."); 210 else { 211 if (execution_result == lldb::eExpressionHitBreakpoint) 212 user_expression_plan->TransferExpressionOwnership(); 213 diagnostic_manager.AppendMessageToDiagnostic( 214 "The process has been left at the point where it was " 215 "interrupted, " 216 "use \"thread return -x\" to return to the state before " 217 "expression evaluation."); 218 } 219 220 return execution_result; 221 } else if (execution_result == lldb::eExpressionStoppedForDebug) { 222 diagnostic_manager.PutString( 223 eDiagnosticSeverityRemark, 224 "Execution was halted at the first instruction of the expression " 225 "function because \"debug\" was requested.\n" 226 "Use \"thread return -x\" to return to the state before expression " 227 "evaluation."); 228 return execution_result; 229 } else if (execution_result == lldb::eExpressionThreadVanished) { 230 diagnostic_manager.Printf( 231 eDiagnosticSeverityError, 232 "Couldn't complete execution; the thread " 233 "on which the expression was being run: 0x%" PRIx64 234 " exited during its execution.", 235 expr_thread_id); 236 return execution_result; 237 } else if (execution_result != lldb::eExpressionCompleted) { 238 diagnostic_manager.Printf( 239 eDiagnosticSeverityError, "Couldn't execute function; result was %s", 240 Process::ExecutionResultAsCString(execution_result)); 241 return execution_result; 242 } 243 } 244 245 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result, 246 function_stack_bottom, function_stack_top)) { 247 return lldb::eExpressionCompleted; 248 } else { 249 return lldb::eExpressionResultUnavailable; 250 } 251 } 252 253 bool LLVMUserExpression::FinalizeJITExecution( 254 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 255 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 256 lldb::addr_t function_stack_top) { 257 Log *log = GetLog(LLDBLog::Expressions); 258 259 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing " 260 "after execution --"); 261 262 if (!m_dematerializer_sp) { 263 diagnostic_manager.Printf(eDiagnosticSeverityError, 264 "Couldn't apply expression side effects : no " 265 "dematerializer is present"); 266 return false; 267 } 268 269 Status dematerialize_error; 270 271 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 272 function_stack_top); 273 274 if (!dematerialize_error.Success()) { 275 diagnostic_manager.Printf(eDiagnosticSeverityError, 276 "Couldn't apply expression side effects : %s", 277 dematerialize_error.AsCString("unknown error")); 278 return false; 279 } 280 281 result = 282 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 283 284 if (result) 285 result->TransferAddress(); 286 287 m_dematerializer_sp.reset(); 288 289 return true; 290 } 291 292 bool LLVMUserExpression::PrepareToExecuteJITExpression( 293 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 294 lldb::addr_t &struct_address) { 295 lldb::TargetSP target; 296 lldb::ProcessSP process; 297 lldb::StackFrameSP frame; 298 299 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 300 diagnostic_manager.PutString( 301 eDiagnosticSeverityError, 302 "The context has changed before we could JIT the expression!"); 303 return false; 304 } 305 306 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 307 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 308 Status alloc_error; 309 310 IRMemoryMap::AllocationPolicy policy = 311 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 312 : IRMemoryMap::eAllocationPolicyMirror; 313 314 const bool zero_memory = false; 315 316 m_materialized_address = m_execution_unit_sp->Malloc( 317 m_materializer_up->GetStructByteSize(), 318 m_materializer_up->GetStructAlignment(), 319 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 320 zero_memory, alloc_error); 321 322 if (!alloc_error.Success()) { 323 diagnostic_manager.Printf( 324 eDiagnosticSeverityError, 325 "Couldn't allocate space for materialized struct: %s", 326 alloc_error.AsCString()); 327 return false; 328 } 329 } 330 331 struct_address = m_materialized_address; 332 333 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 334 Status alloc_error; 335 336 const size_t stack_frame_size = 512 * 1024; 337 338 const bool zero_memory = false; 339 340 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 341 stack_frame_size, 8, 342 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 343 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 344 345 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 346 347 if (!alloc_error.Success()) { 348 diagnostic_manager.Printf( 349 eDiagnosticSeverityError, 350 "Couldn't allocate space for the stack frame: %s", 351 alloc_error.AsCString()); 352 return false; 353 } 354 } 355 356 Status materialize_error; 357 358 m_dematerializer_sp = m_materializer_up->Materialize( 359 frame, *m_execution_unit_sp, struct_address, materialize_error); 360 361 if (!materialize_error.Success()) { 362 diagnostic_manager.Printf(eDiagnosticSeverityError, 363 "Couldn't materialize: %s", 364 materialize_error.AsCString()); 365 return false; 366 } 367 } 368 return true; 369 } 370 371