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