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