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