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