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/Log.h" 34 #include "lldb/Utility/StreamString.h" 35 36 using namespace lldb_private; 37 38 char LLVMUserExpression::ID; 39 40 LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope, 41 llvm::StringRef expr, 42 llvm::StringRef prefix, 43 lldb::LanguageType language, 44 ResultType desired_type, 45 const EvaluateExpressionOptions &options) 46 : UserExpression(exe_scope, expr, prefix, language, desired_type, options), 47 m_stack_frame_bottom(LLDB_INVALID_ADDRESS), 48 m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false), 49 m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(), 50 m_materializer_up(), m_jit_module_wp(), m_can_interpret(false), 51 m_materialized_address(LLDB_INVALID_ADDRESS) {} 52 53 LLVMUserExpression::~LLVMUserExpression() { 54 if (m_target) { 55 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 56 if (jit_module_sp) 57 m_target->GetImages().Remove(jit_module_sp); 58 } 59 } 60 61 lldb::ExpressionResults 62 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager, 63 ExecutionContext &exe_ctx, 64 const EvaluateExpressionOptions &options, 65 lldb::UserExpressionSP &shared_ptr_to_me, 66 lldb::ExpressionVariableSP &result) { 67 // The expression log is quite verbose, and if you're just tracking the 68 // execution of the expression, it's quite convenient to have these logs come 69 // out with the STEP log as well. 70 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | 71 LIBLLDB_LOG_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 (call_plan_sp) { 192 lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo(); 193 if (real_stop_info_sp) 194 error_desc = real_stop_info_sp->GetDescription(); 195 } 196 if (error_desc) 197 diagnostic_manager.Printf(eDiagnosticSeverityError, 198 "Execution was interrupted, reason: %s.", 199 error_desc); 200 else 201 diagnostic_manager.PutString(eDiagnosticSeverityError, 202 "Execution was interrupted."); 203 204 if ((execution_result == lldb::eExpressionInterrupted && 205 options.DoesUnwindOnError()) || 206 (execution_result == lldb::eExpressionHitBreakpoint && 207 options.DoesIgnoreBreakpoints())) 208 diagnostic_manager.AppendMessageToDiagnostic( 209 "The process has been returned to the state before expression " 210 "evaluation."); 211 else { 212 if (execution_result == lldb::eExpressionHitBreakpoint) 213 user_expression_plan->TransferExpressionOwnership(); 214 diagnostic_manager.AppendMessageToDiagnostic( 215 "The process has been left at the point where it was " 216 "interrupted, " 217 "use \"thread return -x\" to return to the state before " 218 "expression evaluation."); 219 } 220 221 return execution_result; 222 } else if (execution_result == lldb::eExpressionStoppedForDebug) { 223 diagnostic_manager.PutString( 224 eDiagnosticSeverityRemark, 225 "Execution was halted at the first instruction of the expression " 226 "function because \"debug\" was requested.\n" 227 "Use \"thread return -x\" to return to the state before expression " 228 "evaluation."); 229 return execution_result; 230 } else if (execution_result == lldb::eExpressionThreadVanished) { 231 diagnostic_manager.Printf( 232 eDiagnosticSeverityError, 233 "Couldn't complete execution; the thread " 234 "on which the expression was being run: 0x%" PRIx64 235 " exited during its execution.", 236 expr_thread_id); 237 return execution_result; 238 } else if (execution_result != lldb::eExpressionCompleted) { 239 diagnostic_manager.Printf( 240 eDiagnosticSeverityError, "Couldn't execute function; result was %s", 241 Process::ExecutionResultAsCString(execution_result)); 242 return execution_result; 243 } 244 } 245 246 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result, 247 function_stack_bottom, function_stack_top)) { 248 return lldb::eExpressionCompleted; 249 } else { 250 return lldb::eExpressionResultUnavailable; 251 } 252 } 253 254 bool LLVMUserExpression::FinalizeJITExecution( 255 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 256 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 257 lldb::addr_t function_stack_top) { 258 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)); 259 260 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing " 261 "after execution --"); 262 263 if (!m_dematerializer_sp) { 264 diagnostic_manager.Printf(eDiagnosticSeverityError, 265 "Couldn't apply expression side effects : no " 266 "dematerializer is present"); 267 return false; 268 } 269 270 Status dematerialize_error; 271 272 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 273 function_stack_top); 274 275 if (!dematerialize_error.Success()) { 276 diagnostic_manager.Printf(eDiagnosticSeverityError, 277 "Couldn't apply expression side effects : %s", 278 dematerialize_error.AsCString("unknown error")); 279 return false; 280 } 281 282 result = 283 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 284 285 if (result) 286 result->TransferAddress(); 287 288 m_dematerializer_sp.reset(); 289 290 return true; 291 } 292 293 bool LLVMUserExpression::PrepareToExecuteJITExpression( 294 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 295 lldb::addr_t &struct_address) { 296 lldb::TargetSP target; 297 lldb::ProcessSP process; 298 lldb::StackFrameSP frame; 299 300 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 301 diagnostic_manager.PutString( 302 eDiagnosticSeverityError, 303 "The context has changed before we could JIT the expression!"); 304 return false; 305 } 306 307 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 308 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 309 Status alloc_error; 310 311 IRMemoryMap::AllocationPolicy policy = 312 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 313 : IRMemoryMap::eAllocationPolicyMirror; 314 315 const bool zero_memory = false; 316 317 m_materialized_address = m_execution_unit_sp->Malloc( 318 m_materializer_up->GetStructByteSize(), 319 m_materializer_up->GetStructAlignment(), 320 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 321 zero_memory, alloc_error); 322 323 if (!alloc_error.Success()) { 324 diagnostic_manager.Printf( 325 eDiagnosticSeverityError, 326 "Couldn't allocate space for materialized struct: %s", 327 alloc_error.AsCString()); 328 return false; 329 } 330 } 331 332 struct_address = m_materialized_address; 333 334 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 335 Status alloc_error; 336 337 const size_t stack_frame_size = 512 * 1024; 338 339 const bool zero_memory = false; 340 341 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 342 stack_frame_size, 8, 343 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 344 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 345 346 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 347 348 if (!alloc_error.Success()) { 349 diagnostic_manager.Printf( 350 eDiagnosticSeverityError, 351 "Couldn't allocate space for the stack frame: %s", 352 alloc_error.AsCString()); 353 return false; 354 } 355 } 356 357 Status materialize_error; 358 359 m_dematerializer_sp = m_materializer_up->Materialize( 360 frame, *m_execution_unit_sp, struct_address, materialize_error); 361 362 if (!materialize_error.Success()) { 363 diagnostic_manager.Printf(eDiagnosticSeverityError, 364 "Couldn't materialize: %s", 365 materialize_error.AsCString()); 366 return false; 367 } 368 } 369 return true; 370 } 371 372