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