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