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/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 Address wrapper_address(m_jit_start_addr); 138 139 std::vector<lldb::addr_t> args; 140 141 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 142 diagnostic_manager.Printf(eDiagnosticSeverityError, 143 "errored out in %s, couldn't AddArguments", 144 __FUNCTION__); 145 return lldb::eExpressionSetupError; 146 } 147 148 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression( 149 exe_ctx.GetThreadRef(), wrapper_address, args, options, 150 shared_ptr_to_me)); 151 152 StreamString ss; 153 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) { 154 diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString()); 155 return lldb::eExpressionSetupError; 156 } 157 158 ThreadPlanCallUserExpression *user_expression_plan = 159 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get()); 160 161 lldb::addr_t function_stack_pointer = 162 user_expression_plan->GetFunctionStackPointer(); 163 164 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize(); 165 function_stack_top = function_stack_pointer; 166 167 LLDB_LOGF(log, 168 "-- [UserExpression::Execute] Execution of expression begins --"); 169 170 if (exe_ctx.GetProcessPtr()) 171 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); 172 173 lldb::ExpressionResults execution_result = 174 exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options, 175 diagnostic_manager); 176 177 if (exe_ctx.GetProcessPtr()) 178 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); 179 180 LLDB_LOGF(log, "-- [UserExpression::Execute] Execution of expression " 181 "completed --"); 182 183 if (execution_result == lldb::eExpressionInterrupted || 184 execution_result == lldb::eExpressionHitBreakpoint) { 185 const char *error_desc = nullptr; 186 187 if (call_plan_sp) { 188 lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo(); 189 if (real_stop_info_sp) 190 error_desc = real_stop_info_sp->GetDescription(); 191 } 192 if (error_desc) 193 diagnostic_manager.Printf(eDiagnosticSeverityError, 194 "Execution was interrupted, reason: %s.", 195 error_desc); 196 else 197 diagnostic_manager.PutString(eDiagnosticSeverityError, 198 "Execution was interrupted."); 199 200 if ((execution_result == lldb::eExpressionInterrupted && 201 options.DoesUnwindOnError()) || 202 (execution_result == lldb::eExpressionHitBreakpoint && 203 options.DoesIgnoreBreakpoints())) 204 diagnostic_manager.AppendMessageToDiagnostic( 205 "The process has been returned to the state before expression " 206 "evaluation."); 207 else { 208 if (execution_result == lldb::eExpressionHitBreakpoint) 209 user_expression_plan->TransferExpressionOwnership(); 210 diagnostic_manager.AppendMessageToDiagnostic( 211 "The process has been left at the point where it was " 212 "interrupted, " 213 "use \"thread return -x\" to return to the state before " 214 "expression evaluation."); 215 } 216 217 return execution_result; 218 } else if (execution_result == lldb::eExpressionStoppedForDebug) { 219 diagnostic_manager.PutString( 220 eDiagnosticSeverityRemark, 221 "Execution was halted at the first instruction of the expression " 222 "function because \"debug\" was requested.\n" 223 "Use \"thread return -x\" to return to the state before expression " 224 "evaluation."); 225 return execution_result; 226 } else if (execution_result != lldb::eExpressionCompleted) { 227 diagnostic_manager.Printf( 228 eDiagnosticSeverityError, "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 } 241 242 bool LLVMUserExpression::FinalizeJITExecution( 243 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 244 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 245 lldb::addr_t function_stack_top) { 246 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)); 247 248 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing " 249 "after execution --"); 250 251 if (!m_dematerializer_sp) { 252 diagnostic_manager.Printf(eDiagnosticSeverityError, 253 "Couldn't apply expression side effects : no " 254 "dematerializer is present"); 255 return false; 256 } 257 258 Status dematerialize_error; 259 260 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 261 function_stack_top); 262 263 if (!dematerialize_error.Success()) { 264 diagnostic_manager.Printf(eDiagnosticSeverityError, 265 "Couldn't apply expression side effects : %s", 266 dematerialize_error.AsCString("unknown error")); 267 return false; 268 } 269 270 result = 271 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 272 273 if (result) 274 result->TransferAddress(); 275 276 m_dematerializer_sp.reset(); 277 278 return true; 279 } 280 281 bool LLVMUserExpression::PrepareToExecuteJITExpression( 282 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 283 lldb::addr_t &struct_address) { 284 lldb::TargetSP target; 285 lldb::ProcessSP process; 286 lldb::StackFrameSP frame; 287 288 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 289 diagnostic_manager.PutString( 290 eDiagnosticSeverityError, 291 "The context has changed before we could JIT the expression!"); 292 return false; 293 } 294 295 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 296 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 297 Status alloc_error; 298 299 IRMemoryMap::AllocationPolicy policy = 300 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 301 : IRMemoryMap::eAllocationPolicyMirror; 302 303 const bool zero_memory = false; 304 305 m_materialized_address = m_execution_unit_sp->Malloc( 306 m_materializer_up->GetStructByteSize(), 307 m_materializer_up->GetStructAlignment(), 308 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 309 zero_memory, alloc_error); 310 311 if (!alloc_error.Success()) { 312 diagnostic_manager.Printf( 313 eDiagnosticSeverityError, 314 "Couldn't allocate space for materialized struct: %s", 315 alloc_error.AsCString()); 316 return false; 317 } 318 } 319 320 struct_address = m_materialized_address; 321 322 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 323 Status alloc_error; 324 325 const size_t stack_frame_size = 512 * 1024; 326 327 const bool zero_memory = false; 328 329 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 330 stack_frame_size, 8, 331 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 332 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 333 334 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 335 336 if (!alloc_error.Success()) { 337 diagnostic_manager.Printf( 338 eDiagnosticSeverityError, 339 "Couldn't allocate space for the stack frame: %s", 340 alloc_error.AsCString()); 341 return false; 342 } 343 } 344 345 Status materialize_error; 346 347 m_dematerializer_sp = m_materializer_up->Materialize( 348 frame, *m_execution_unit_sp, struct_address, materialize_error); 349 350 if (!materialize_error.Success()) { 351 diagnostic_manager.Printf(eDiagnosticSeverityError, 352 "Couldn't materialize: %s", 353 materialize_error.AsCString()); 354 return false; 355 } 356 } 357 return true; 358 } 359 360 lldb::ModuleSP LLVMUserExpression::GetJITModule() { 361 if (m_execution_unit_sp) 362 return m_execution_unit_sp->GetJITModule(); 363 return lldb::ModuleSP(); 364 } 365