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/ExpressionSourceCode.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/ClangASTContext.h" 22 #include "lldb/Symbol/ClangExternalASTSourceCommon.h" 23 #include "lldb/Symbol/Function.h" 24 #include "lldb/Symbol/ObjectFile.h" 25 #include "lldb/Symbol/SymbolVendor.h" 26 #include "lldb/Symbol/Type.h" 27 #include "lldb/Symbol/VariableList.h" 28 #include "lldb/Target/ExecutionContext.h" 29 #include "lldb/Target/Process.h" 30 #include "lldb/Target/StackFrame.h" 31 #include "lldb/Target/Target.h" 32 #include "lldb/Target/ThreadPlan.h" 33 #include "lldb/Target/ThreadPlanCallUserExpression.h" 34 #include "lldb/Utility/ConstString.h" 35 #include "lldb/Utility/Log.h" 36 #include "lldb/Utility/StreamString.h" 37 38 using namespace lldb_private; 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), 49 m_allow_cxx(false), 50 m_allow_objc(false), 51 m_transformed_text(), 52 m_execution_unit_sp(), m_materializer_ap(), m_jit_module_wp(), 53 m_enforce_valid_object(true), m_in_cplusplus_method(false), 54 m_in_objectivec_method(false), m_in_static_method(false), 55 m_needs_object_ptr(false), m_target(NULL), m_can_interpret(false), 56 m_materialized_address(LLDB_INVALID_ADDRESS) {} 57 58 LLVMUserExpression::~LLVMUserExpression() { 59 if (m_target) { 60 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 61 if (jit_module_sp) 62 m_target->GetImages().Remove(jit_module_sp); 63 } 64 } 65 66 lldb::ExpressionResults 67 LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager, 68 ExecutionContext &exe_ctx, 69 const EvaluateExpressionOptions &options, 70 lldb::UserExpressionSP &shared_ptr_to_me, 71 lldb::ExpressionVariableSP &result) { 72 // The expression log is quite verbose, and if you're just tracking the 73 // execution of the expression, it's quite convenient to have these logs come 74 // out with the STEP log as well. 75 Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS | 76 LIBLLDB_LOG_STEP)); 77 78 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 79 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS; 80 81 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx, 82 struct_address)) { 83 diagnostic_manager.Printf( 84 eDiagnosticSeverityError, 85 "errored out in %s, couldn't PrepareToExecuteJITExpression", 86 __FUNCTION__); 87 return lldb::eExpressionSetupError; 88 } 89 90 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS; 91 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS; 92 93 if (m_can_interpret) { 94 llvm::Module *module = m_execution_unit_sp->GetModule(); 95 llvm::Function *function = m_execution_unit_sp->GetFunction(); 96 97 if (!module || !function) { 98 diagnostic_manager.PutString( 99 eDiagnosticSeverityError, 100 "supposed to interpret, but nothing is there"); 101 return lldb::eExpressionSetupError; 102 } 103 104 Status interpreter_error; 105 106 std::vector<lldb::addr_t> args; 107 108 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 109 diagnostic_manager.Printf(eDiagnosticSeverityError, 110 "errored out in %s, couldn't AddArguments", 111 __FUNCTION__); 112 return lldb::eExpressionSetupError; 113 } 114 115 function_stack_bottom = m_stack_frame_bottom; 116 function_stack_top = m_stack_frame_top; 117 118 IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp, 119 interpreter_error, function_stack_bottom, 120 function_stack_top, exe_ctx); 121 122 if (!interpreter_error.Success()) { 123 diagnostic_manager.Printf(eDiagnosticSeverityError, 124 "supposed to interpret, but failed: %s", 125 interpreter_error.AsCString()); 126 return lldb::eExpressionDiscarded; 127 } 128 } else { 129 if (!exe_ctx.HasThreadScope()) { 130 diagnostic_manager.Printf(eDiagnosticSeverityError, 131 "%s called with no thread selected", 132 __FUNCTION__); 133 return lldb::eExpressionSetupError; 134 } 135 136 Address wrapper_address(m_jit_start_addr); 137 138 std::vector<lldb::addr_t> args; 139 140 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) { 141 diagnostic_manager.Printf(eDiagnosticSeverityError, 142 "errored out in %s, couldn't AddArguments", 143 __FUNCTION__); 144 return lldb::eExpressionSetupError; 145 } 146 147 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression( 148 exe_ctx.GetThreadRef(), wrapper_address, args, options, 149 shared_ptr_to_me)); 150 151 StreamString ss; 152 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) { 153 diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString()); 154 return lldb::eExpressionSetupError; 155 } 156 157 ThreadPlanCallUserExpression *user_expression_plan = 158 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get()); 159 160 lldb::addr_t function_stack_pointer = 161 user_expression_plan->GetFunctionStackPointer(); 162 163 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize(); 164 function_stack_top = function_stack_pointer; 165 166 if (log) 167 log->Printf( 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 if (log) 181 log->Printf("-- [UserExpression::Execute] Execution of expression " 182 "completed --"); 183 184 if (execution_result == lldb::eExpressionInterrupted || 185 execution_result == lldb::eExpressionHitBreakpoint) { 186 const char *error_desc = NULL; 187 188 if (call_plan_sp) { 189 lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo(); 190 if (real_stop_info_sp) 191 error_desc = real_stop_info_sp->GetDescription(); 192 } 193 if (error_desc) 194 diagnostic_manager.Printf(eDiagnosticSeverityError, 195 "Execution was interrupted, reason: %s.", 196 error_desc); 197 else 198 diagnostic_manager.PutString(eDiagnosticSeverityError, 199 "Execution was interrupted."); 200 201 if ((execution_result == lldb::eExpressionInterrupted && 202 options.DoesUnwindOnError()) || 203 (execution_result == lldb::eExpressionHitBreakpoint && 204 options.DoesIgnoreBreakpoints())) 205 diagnostic_manager.AppendMessageToDiagnostic( 206 "The process has been returned to the state before expression " 207 "evaluation."); 208 else { 209 if (execution_result == lldb::eExpressionHitBreakpoint) 210 user_expression_plan->TransferExpressionOwnership(); 211 diagnostic_manager.AppendMessageToDiagnostic( 212 "The process has been left at the point where it was " 213 "interrupted, " 214 "use \"thread return -x\" to return to the state before " 215 "expression evaluation."); 216 } 217 218 return execution_result; 219 } else if (execution_result == lldb::eExpressionStoppedForDebug) { 220 diagnostic_manager.PutString( 221 eDiagnosticSeverityRemark, 222 "Execution was halted at the first instruction of the expression " 223 "function because \"debug\" was requested.\n" 224 "Use \"thread return -x\" to return to the state before expression " 225 "evaluation."); 226 return execution_result; 227 } else if (execution_result != lldb::eExpressionCompleted) { 228 diagnostic_manager.Printf( 229 eDiagnosticSeverityError, 230 "Couldn't execute function; result was %s", 231 Process::ExecutionResultAsCString(execution_result)); 232 return execution_result; 233 } 234 } 235 236 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result, 237 function_stack_bottom, function_stack_top)) { 238 return lldb::eExpressionCompleted; 239 } else { 240 return lldb::eExpressionResultUnavailable; 241 } 242 } else { 243 diagnostic_manager.PutString( 244 eDiagnosticSeverityError, 245 "Expression can't be run, because there is no JIT compiled function"); 246 return lldb::eExpressionSetupError; 247 } 248 } 249 250 bool LLVMUserExpression::FinalizeJITExecution( 251 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 252 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom, 253 lldb::addr_t function_stack_top) { 254 Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)); 255 256 if (log) 257 log->Printf("-- [UserExpression::FinalizeJITExecution] Dematerializing " 258 "after execution --"); 259 260 if (!m_dematerializer_sp) { 261 diagnostic_manager.Printf(eDiagnosticSeverityError, 262 "Couldn't apply expression side effects : no " 263 "dematerializer is present"); 264 return false; 265 } 266 267 Status dematerialize_error; 268 269 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom, 270 function_stack_top); 271 272 if (!dematerialize_error.Success()) { 273 diagnostic_manager.Printf(eDiagnosticSeverityError, 274 "Couldn't apply expression side effects : %s", 275 dematerialize_error.AsCString("unknown error")); 276 return false; 277 } 278 279 result = 280 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope()); 281 282 if (result) 283 result->TransferAddress(); 284 285 m_dematerializer_sp.reset(); 286 287 return true; 288 } 289 290 bool LLVMUserExpression::PrepareToExecuteJITExpression( 291 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx, 292 lldb::addr_t &struct_address) { 293 lldb::TargetSP target; 294 lldb::ProcessSP process; 295 lldb::StackFrameSP frame; 296 297 if (!LockAndCheckContext(exe_ctx, target, process, frame)) { 298 diagnostic_manager.PutString( 299 eDiagnosticSeverityError, 300 "The context has changed before we could JIT the expression!"); 301 return false; 302 } 303 304 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) { 305 if (m_materialized_address == LLDB_INVALID_ADDRESS) { 306 Status alloc_error; 307 308 IRMemoryMap::AllocationPolicy policy = 309 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly 310 : IRMemoryMap::eAllocationPolicyMirror; 311 312 const bool zero_memory = false; 313 314 m_materialized_address = m_execution_unit_sp->Malloc( 315 m_materializer_ap->GetStructByteSize(), 316 m_materializer_ap->GetStructAlignment(), 317 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy, 318 zero_memory, alloc_error); 319 320 if (!alloc_error.Success()) { 321 diagnostic_manager.Printf( 322 eDiagnosticSeverityError, 323 "Couldn't allocate space for materialized struct: %s", 324 alloc_error.AsCString()); 325 return false; 326 } 327 } 328 329 struct_address = m_materialized_address; 330 331 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) { 332 Status alloc_error; 333 334 const size_t stack_frame_size = 512 * 1024; 335 336 const bool zero_memory = false; 337 338 m_stack_frame_bottom = m_execution_unit_sp->Malloc( 339 stack_frame_size, 8, 340 lldb::ePermissionsReadable | lldb::ePermissionsWritable, 341 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error); 342 343 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size; 344 345 if (!alloc_error.Success()) { 346 diagnostic_manager.Printf( 347 eDiagnosticSeverityError, 348 "Couldn't allocate space for the stack frame: %s", 349 alloc_error.AsCString()); 350 return false; 351 } 352 } 353 354 Status materialize_error; 355 356 m_dematerializer_sp = m_materializer_ap->Materialize( 357 frame, *m_execution_unit_sp, struct_address, materialize_error); 358 359 if (!materialize_error.Success()) { 360 diagnostic_manager.Printf(eDiagnosticSeverityError, 361 "Couldn't materialize: %s", 362 materialize_error.AsCString()); 363 return false; 364 } 365 } 366 return true; 367 } 368 369 lldb::ModuleSP LLVMUserExpression::GetJITModule() { 370 if (m_execution_unit_sp) 371 return m_execution_unit_sp->GetJITModule(); 372 return lldb::ModuleSP(); 373 } 374