1 //===-- FunctionCaller.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 #include "lldb/Expression/FunctionCaller.h" 10 #include "lldb/Core/Module.h" 11 #include "lldb/Core/Progress.h" 12 #include "lldb/Expression/DiagnosticManager.h" 13 #include "lldb/Expression/IRExecutionUnit.h" 14 #include "lldb/Interpreter/CommandReturnObject.h" 15 #include "lldb/Symbol/Function.h" 16 #include "lldb/Symbol/Type.h" 17 #include "lldb/Target/ExecutionContext.h" 18 #include "lldb/Target/Process.h" 19 #include "lldb/Target/RegisterContext.h" 20 #include "lldb/Target/Target.h" 21 #include "lldb/Target/Thread.h" 22 #include "lldb/Target/ThreadPlan.h" 23 #include "lldb/Target/ThreadPlanCallFunction.h" 24 #include "lldb/Utility/DataExtractor.h" 25 #include "lldb/Utility/ErrorMessages.h" 26 #include "lldb/Utility/LLDBLog.h" 27 #include "lldb/Utility/Log.h" 28 #include "lldb/Utility/State.h" 29 #include "lldb/ValueObject/ValueObject.h" 30 #include "lldb/ValueObject/ValueObjectList.h" 31 32 using namespace lldb_private; 33 34 char FunctionCaller::ID; 35 36 // FunctionCaller constructor 37 FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope, 38 const CompilerType &return_type, 39 const Address &functionAddress, 40 const ValueList &arg_value_list, 41 const char *name) 42 : Expression(exe_scope), m_execution_unit_sp(), m_parser(), 43 m_jit_module_wp(), m_name(name ? name : "<unknown>"), 44 m_function_ptr(nullptr), m_function_addr(functionAddress), 45 m_function_return_type(return_type), 46 m_wrapper_function_name("__lldb_caller_function"), 47 m_wrapper_struct_name("__lldb_caller_struct"), m_wrapper_args_addrs(), 48 m_struct_valid(false), m_struct_size(0), m_return_size(0), 49 m_return_offset(0), m_arg_values(arg_value_list), m_compiled(false), 50 m_JITted(false) { 51 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess()); 52 // Can't make a FunctionCaller without a process. 53 assert(m_jit_process_wp.lock()); 54 } 55 56 // Destructor 57 FunctionCaller::~FunctionCaller() { 58 lldb::ProcessSP process_sp(m_jit_process_wp.lock()); 59 if (process_sp) { 60 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock()); 61 if (jit_module_sp) 62 process_sp->GetTarget().GetImages().Remove(jit_module_sp); 63 } 64 } 65 66 bool FunctionCaller::WriteFunctionWrapper( 67 ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) { 68 Process *process = exe_ctx.GetProcessPtr(); 69 70 if (!process) { 71 diagnostic_manager.Printf(lldb::eSeverityError, "no process."); 72 return false; 73 } 74 75 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); 76 77 if (process != jit_process_sp.get()) { 78 diagnostic_manager.Printf(lldb::eSeverityError, 79 "process does not match the stored process."); 80 return false; 81 } 82 83 if (process->GetState() != lldb::eStateStopped) { 84 diagnostic_manager.Printf(lldb::eSeverityError, "process is not stopped"); 85 return false; 86 } 87 88 if (!m_compiled) { 89 diagnostic_manager.Printf(lldb::eSeverityError, "function not compiled"); 90 return false; 91 } 92 93 if (m_JITted) 94 return true; 95 96 bool can_interpret = false; // should stay that way 97 98 Status jit_error(m_parser->PrepareForExecution( 99 m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx, 100 can_interpret, eExecutionPolicyAlways)); 101 102 if (!jit_error.Success()) { 103 diagnostic_manager.Printf(lldb::eSeverityError, 104 "Error in PrepareForExecution: %s.", 105 jit_error.AsCString()); 106 return false; 107 } 108 109 if (m_parser->GetGenerateDebugInfo()) { 110 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule()); 111 112 if (jit_module_sp) { 113 ConstString const_func_name(FunctionName()); 114 FileSpec jit_file; 115 jit_file.SetFilename(const_func_name); 116 jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString()); 117 m_jit_module_wp = jit_module_sp; 118 process->GetTarget().GetImages().Append(jit_module_sp, 119 true /* notify */); 120 } 121 } 122 if (process && m_jit_start_addr) 123 m_jit_process_wp = process->shared_from_this(); 124 125 m_JITted = true; 126 127 return true; 128 } 129 130 bool FunctionCaller::WriteFunctionArguments( 131 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, 132 DiagnosticManager &diagnostic_manager) { 133 return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values, 134 diagnostic_manager); 135 } 136 137 // FIXME: Assure that the ValueList we were passed in is consistent with the one 138 // that defined this function. 139 140 bool FunctionCaller::WriteFunctionArguments( 141 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref, 142 ValueList &arg_values, DiagnosticManager &diagnostic_manager) { 143 // All the information to reconstruct the struct is provided by the 144 // StructExtractor. 145 if (!m_struct_valid) { 146 diagnostic_manager.PutString(lldb::eSeverityError, 147 "Argument information was not correctly " 148 "parsed, so the function cannot be called."); 149 return false; 150 } 151 152 Status error; 153 lldb::ExpressionResults return_value = lldb::eExpressionSetupError; 154 155 Process *process = exe_ctx.GetProcessPtr(); 156 157 if (process == nullptr) 158 return return_value; 159 160 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); 161 162 if (process != jit_process_sp.get()) 163 return false; 164 165 if (args_addr_ref == LLDB_INVALID_ADDRESS) { 166 args_addr_ref = process->AllocateMemory( 167 m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable, 168 error); 169 if (args_addr_ref == LLDB_INVALID_ADDRESS) 170 return false; 171 m_wrapper_args_addrs.push_back(args_addr_ref); 172 } else { 173 // Make sure this is an address that we've already handed out. 174 if (find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), 175 args_addr_ref) == m_wrapper_args_addrs.end()) { 176 return false; 177 } 178 } 179 180 // TODO: verify fun_addr needs to be a callable address 181 Scalar fun_addr( 182 m_function_addr.GetCallableLoadAddress(exe_ctx.GetTargetPtr())); 183 uint64_t first_offset = m_member_offsets[0]; 184 process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr, 185 process->GetAddressByteSize(), error); 186 187 // FIXME: We will need to extend this for Variadic functions. 188 189 Status value_error; 190 191 size_t num_args = arg_values.GetSize(); 192 if (num_args != m_arg_values.GetSize()) { 193 diagnostic_manager.Printf( 194 lldb::eSeverityError, 195 "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "", 196 (uint64_t)num_args, (uint64_t)m_arg_values.GetSize()); 197 return false; 198 } 199 200 for (size_t i = 0; i < num_args; i++) { 201 // FIXME: We should sanity check sizes. 202 203 uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes. 204 Value *arg_value = arg_values.GetValueAtIndex(i); 205 206 // FIXME: For now just do scalars: 207 208 // Special case: if it's a pointer, don't do anything (the ABI supports 209 // passing cstrings) 210 211 if (arg_value->GetValueType() == Value::ValueType::HostAddress && 212 arg_value->GetContextType() == Value::ContextType::Invalid && 213 arg_value->GetCompilerType().IsPointerType()) 214 continue; 215 216 const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx); 217 218 if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar, 219 arg_scalar.GetByteSize(), error)) 220 return false; 221 } 222 223 return true; 224 } 225 226 bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx, 227 lldb::addr_t &args_addr_ref, 228 DiagnosticManager &diagnostic_manager) { 229 // Since we might need to call allocate memory and maybe call code to make 230 // the caller, we need to be stopped. 231 Process *process = exe_ctx.GetProcessPtr(); 232 if (!process) { 233 diagnostic_manager.PutString(lldb::eSeverityError, "no process"); 234 return false; 235 } 236 if (process->GetState() != lldb::eStateStopped) { 237 diagnostic_manager.PutString(lldb::eSeverityError, "process running"); 238 return false; 239 } 240 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0) 241 return false; 242 if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager)) 243 return false; 244 if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager)) 245 return false; 246 247 Log *log = GetLog(LLDBLog::Step); 248 LLDB_LOGF(log, "Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n", 249 m_jit_start_addr, args_addr_ref); 250 251 return true; 252 } 253 254 lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction( 255 ExecutionContext &exe_ctx, lldb::addr_t args_addr, 256 const EvaluateExpressionOptions &options, 257 DiagnosticManager &diagnostic_manager) { 258 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step)); 259 260 LLDB_LOGF(log, 261 "-- [FunctionCaller::GetThreadPlanToCallFunction] Creating " 262 "thread plan to call function \"%s\" --", 263 m_name.c_str()); 264 265 // FIXME: Use the errors Stream for better error reporting. 266 Thread *thread = exe_ctx.GetThreadPtr(); 267 if (thread == nullptr) { 268 diagnostic_manager.PutString( 269 lldb::eSeverityError, "Can't call a function without a valid thread."); 270 return nullptr; 271 } 272 273 // Okay, now run the function: 274 275 Address wrapper_address(m_jit_start_addr); 276 277 lldb::addr_t args = {args_addr}; 278 279 lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction( 280 *thread, wrapper_address, CompilerType(), args, options)); 281 new_plan_sp->SetIsControllingPlan(true); 282 new_plan_sp->SetOkayToDiscard(false); 283 return new_plan_sp; 284 } 285 286 bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx, 287 lldb::addr_t args_addr, 288 Value &ret_value) { 289 // Read the return value - it is the last field in the struct: 290 // FIXME: How does clang tell us there's no return value? We need to handle 291 // that case. 292 // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and 293 // then use GetReturnValueObject 294 // to fetch the value. That way we can fetch any values we need. 295 296 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step)); 297 298 LLDB_LOGF(log, 299 "-- [FunctionCaller::FetchFunctionResults] Fetching function " 300 "results for \"%s\"--", 301 m_name.c_str()); 302 303 Process *process = exe_ctx.GetProcessPtr(); 304 305 if (process == nullptr) 306 return false; 307 308 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock()); 309 310 if (process != jit_process_sp.get()) 311 return false; 312 313 Status error; 314 ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory( 315 args_addr + m_return_offset, m_return_size, 0, error); 316 317 if (error.Fail()) 318 return false; 319 320 ret_value.SetCompilerType(m_function_return_type); 321 ret_value.SetValueType(Value::ValueType::Scalar); 322 return true; 323 } 324 325 void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx, 326 lldb::addr_t args_addr) { 327 std::list<lldb::addr_t>::iterator pos; 328 pos = std::find(m_wrapper_args_addrs.begin(), m_wrapper_args_addrs.end(), 329 args_addr); 330 if (pos != m_wrapper_args_addrs.end()) 331 m_wrapper_args_addrs.erase(pos); 332 333 exe_ctx.GetProcessRef().DeallocateMemory(args_addr); 334 } 335 336 lldb::ExpressionResults FunctionCaller::ExecuteFunction( 337 ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr, 338 const EvaluateExpressionOptions &options, 339 DiagnosticManager &diagnostic_manager, Value &results) { 340 lldb::ExpressionResults return_value = lldb::eExpressionSetupError; 341 342 Debugger *debugger = 343 exe_ctx.GetTargetPtr() ? &exe_ctx.GetTargetPtr()->GetDebugger() : nullptr; 344 Progress progress("Calling function", FunctionName(), {}, debugger); 345 346 // FunctionCaller::ExecuteFunction execution is always just to get the 347 // result. Unless explicitly asked for, ignore breakpoints and unwind on 348 // error. 349 const bool enable_debugging = 350 exe_ctx.GetTargetPtr() && 351 exe_ctx.GetTargetPtr()->GetDebugUtilityExpression(); 352 EvaluateExpressionOptions real_options = options; 353 real_options.SetDebug(false); // This halts the expression for debugging. 354 real_options.SetGenerateDebugInfo(enable_debugging); 355 real_options.SetUnwindOnError(!enable_debugging); 356 real_options.SetIgnoreBreakpoints(!enable_debugging); 357 358 lldb::addr_t args_addr; 359 360 if (args_addr_ptr != nullptr) 361 args_addr = *args_addr_ptr; 362 else 363 args_addr = LLDB_INVALID_ADDRESS; 364 365 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0) 366 return lldb::eExpressionSetupError; 367 368 if (args_addr == LLDB_INVALID_ADDRESS) { 369 if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager)) 370 return lldb::eExpressionSetupError; 371 } 372 373 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step)); 374 375 LLDB_LOGF(log, 376 "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==", 377 m_name.c_str()); 378 379 lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction( 380 exe_ctx, args_addr, real_options, diagnostic_manager); 381 if (!call_plan_sp) 382 return lldb::eExpressionSetupError; 383 384 // We need to make sure we record the fact that we are running an expression 385 // here otherwise this fact will fail to be recorded when fetching an 386 // Objective-C object description 387 if (exe_ctx.GetProcessPtr()) 388 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true); 389 390 return_value = exe_ctx.GetProcessRef().RunThreadPlan( 391 exe_ctx, call_plan_sp, real_options, diagnostic_manager); 392 393 if (log) { 394 if (return_value != lldb::eExpressionCompleted) { 395 LLDB_LOGF(log, 396 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" " 397 "completed abnormally: %s ==", 398 m_name.c_str(), toString(return_value).c_str()); 399 } else { 400 LLDB_LOGF(log, 401 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" " 402 "completed normally ==", 403 m_name.c_str()); 404 } 405 } 406 407 if (exe_ctx.GetProcessPtr()) 408 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false); 409 410 if (args_addr_ptr != nullptr) 411 *args_addr_ptr = args_addr; 412 413 if (return_value != lldb::eExpressionCompleted) 414 return return_value; 415 416 FetchFunctionResults(exe_ctx, args_addr, results); 417 418 if (args_addr_ptr == nullptr) 419 DeallocateFunctionResults(exe_ctx, args_addr); 420 421 return lldb::eExpressionCompleted; 422 } 423