420 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9#include "lldb/Expression/FunctionCaller.h"10#include "lldb/Core/Module.h"11#include "lldb/Core/Progress.h"12#include "lldb/Expression/DiagnosticManager.h"13#include "lldb/Expression/IRExecutionUnit.h"14#include "lldb/Interpreter/CommandReturnObject.h"15#include "lldb/Symbol/Function.h"16#include "lldb/Symbol/Type.h"17#include "lldb/Target/ExecutionContext.h"18#include "lldb/Target/Process.h"19#include "lldb/Target/RegisterContext.h"20#include "lldb/Target/Target.h"21#include "lldb/Target/Thread.h"22#include "lldb/Target/ThreadPlan.h"23#include "lldb/Target/ThreadPlanCallFunction.h"24#include "lldb/Utility/DataExtractor.h"25#include "lldb/Utility/ErrorMessages.h"26#include "lldb/Utility/LLDBLog.h"27#include "lldb/Utility/Log.h"28#include "lldb/Utility/State.h"29#include "lldb/ValueObject/ValueObject.h"30#include "lldb/ValueObject/ValueObjectList.h"31 32using namespace lldb_private;33 34char FunctionCaller::ID;35 36// FunctionCaller constructor37FunctionCaller::FunctionCaller(ExecutionContextScope &exe_scope,38 const CompilerType &return_type,39 const Address &functionAddress,40 const ValueList &arg_value_list,41 const char *name)42 : Expression(exe_scope), m_execution_unit_sp(), m_parser(),43 m_jit_module_wp(), m_name(name ? name : "<unknown>"),44 m_function_ptr(nullptr), m_function_addr(functionAddress),45 m_function_return_type(return_type),46 m_wrapper_function_name("__lldb_caller_function"),47 m_wrapper_struct_name("__lldb_caller_struct"), m_wrapper_args_addrs(),48 m_struct_valid(false), m_struct_size(0), m_return_size(0),49 m_return_offset(0), m_arg_values(arg_value_list), m_compiled(false),50 m_JITted(false) {51 m_jit_process_wp = lldb::ProcessWP(exe_scope.CalculateProcess());52 // Can't make a FunctionCaller without a process.53 assert(m_jit_process_wp.lock());54}55 56// Destructor57FunctionCaller::~FunctionCaller() {58 lldb::ProcessSP process_sp(m_jit_process_wp.lock());59 if (process_sp) {60 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());61 if (jit_module_sp)62 process_sp->GetTarget().GetImages().Remove(jit_module_sp);63 }64}65 66bool FunctionCaller::WriteFunctionWrapper(67 ExecutionContext &exe_ctx, DiagnosticManager &diagnostic_manager) {68 Process *process = exe_ctx.GetProcessPtr();69 70 if (!process) {71 diagnostic_manager.Printf(lldb::eSeverityError, "no process.");72 return false;73 }74 75 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());76 77 if (process != jit_process_sp.get()) {78 diagnostic_manager.Printf(lldb::eSeverityError,79 "process does not match the stored process.");80 return false;81 }82 83 if (process->GetState() != lldb::eStateStopped) {84 diagnostic_manager.Printf(lldb::eSeverityError, "process is not stopped");85 return false;86 }87 88 if (!m_compiled) {89 diagnostic_manager.Printf(lldb::eSeverityError, "function not compiled");90 return false;91 }92 93 if (m_JITted)94 return true;95 96 bool can_interpret = false; // should stay that way97 98 Status jit_error(m_parser->PrepareForExecution(99 m_jit_start_addr, m_jit_end_addr, m_execution_unit_sp, exe_ctx,100 can_interpret, eExecutionPolicyAlways));101 102 if (!jit_error.Success()) {103 diagnostic_manager.Printf(lldb::eSeverityError,104 "Error in PrepareForExecution: %s.",105 jit_error.AsCString());106 return false;107 }108 109 if (m_parser->GetGenerateDebugInfo()) {110 lldb::ModuleSP jit_module_sp(m_execution_unit_sp->GetJITModule());111 112 if (jit_module_sp) {113 ConstString const_func_name(FunctionName());114 FileSpec jit_file;115 jit_file.SetFilename(const_func_name);116 jit_module_sp->SetFileSpecAndObjectName(jit_file, ConstString());117 m_jit_module_wp = jit_module_sp;118 process->GetTarget().GetImages().Append(jit_module_sp,119 true /* notify */);120 }121 }122 if (process && m_jit_start_addr)123 m_jit_process_wp = process->shared_from_this();124 125 m_JITted = true;126 127 return true;128}129 130bool FunctionCaller::WriteFunctionArguments(131 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,132 DiagnosticManager &diagnostic_manager) {133 return WriteFunctionArguments(exe_ctx, args_addr_ref, m_arg_values,134 diagnostic_manager);135}136 137// FIXME: Assure that the ValueList we were passed in is consistent with the one138// that defined this function.139 140bool FunctionCaller::WriteFunctionArguments(141 ExecutionContext &exe_ctx, lldb::addr_t &args_addr_ref,142 ValueList &arg_values, DiagnosticManager &diagnostic_manager) {143 // All the information to reconstruct the struct is provided by the144 // StructExtractor.145 if (!m_struct_valid) {146 diagnostic_manager.PutString(lldb::eSeverityError,147 "Argument information was not correctly "148 "parsed, so the function cannot be called.");149 return false;150 }151 152 Status error;153 lldb::ExpressionResults return_value = lldb::eExpressionSetupError;154 155 Process *process = exe_ctx.GetProcessPtr();156 157 if (process == nullptr)158 return return_value;159 160 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());161 162 if (process != jit_process_sp.get())163 return false;164 165 if (args_addr_ref == LLDB_INVALID_ADDRESS) {166 args_addr_ref = process->AllocateMemory(167 m_struct_size, lldb::ePermissionsReadable | lldb::ePermissionsWritable,168 error);169 if (args_addr_ref == LLDB_INVALID_ADDRESS)170 return false;171 m_wrapper_args_addrs.push_back(args_addr_ref);172 } else {173 // Make sure this is an address that we've already handed out.174 if (!llvm::is_contained(m_wrapper_args_addrs, args_addr_ref))175 return false;176 }177 178 // TODO: verify fun_addr needs to be a callable address179 Scalar fun_addr(180 m_function_addr.GetCallableLoadAddress(exe_ctx.GetTargetPtr()));181 uint64_t first_offset = m_member_offsets[0];182 process->WriteScalarToMemory(args_addr_ref + first_offset, fun_addr,183 process->GetAddressByteSize(), error);184 185 // FIXME: We will need to extend this for Variadic functions.186 187 Status value_error;188 189 size_t num_args = arg_values.GetSize();190 if (num_args != m_arg_values.GetSize()) {191 diagnostic_manager.Printf(192 lldb::eSeverityError,193 "Wrong number of arguments - was: %" PRIu64 " should be: %" PRIu64 "",194 (uint64_t)num_args, (uint64_t)m_arg_values.GetSize());195 return false;196 }197 198 for (size_t i = 0; i < num_args; i++) {199 // FIXME: We should sanity check sizes.200 201 uint64_t offset = m_member_offsets[i + 1]; // Clang sizes are in bytes.202 Value *arg_value = arg_values.GetValueAtIndex(i);203 204 // FIXME: For now just do scalars:205 206 // Special case: if it's a pointer, don't do anything (the ABI supports207 // passing cstrings)208 209 if (arg_value->GetValueType() == Value::ValueType::HostAddress &&210 arg_value->GetContextType() == Value::ContextType::Invalid &&211 arg_value->GetCompilerType().IsPointerType())212 continue;213 214 const Scalar &arg_scalar = arg_value->ResolveValue(&exe_ctx);215 216 if (!process->WriteScalarToMemory(args_addr_ref + offset, arg_scalar,217 arg_scalar.GetByteSize(), error))218 return false;219 }220 221 return true;222}223 224bool FunctionCaller::InsertFunction(ExecutionContext &exe_ctx,225 lldb::addr_t &args_addr_ref,226 DiagnosticManager &diagnostic_manager) {227 // Since we might need to call allocate memory and maybe call code to make228 // the caller, we need to be stopped.229 Process *process = exe_ctx.GetProcessPtr();230 if (!process) {231 diagnostic_manager.PutString(lldb::eSeverityError, "no process");232 return false;233 }234 if (process->GetState() != lldb::eStateStopped) {235 diagnostic_manager.PutString(lldb::eSeverityError, "process running");236 return false;237 }238 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)239 return false;240 if (!WriteFunctionWrapper(exe_ctx, diagnostic_manager))241 return false;242 if (!WriteFunctionArguments(exe_ctx, args_addr_ref, diagnostic_manager))243 return false;244 245 Log *log = GetLog(LLDBLog::Step);246 LLDB_LOGF(log, "Call Address: 0x%" PRIx64 " Struct Address: 0x%" PRIx64 ".\n",247 m_jit_start_addr, args_addr_ref);248 249 return true;250}251 252lldb::ThreadPlanSP FunctionCaller::GetThreadPlanToCallFunction(253 ExecutionContext &exe_ctx, lldb::addr_t args_addr,254 const EvaluateExpressionOptions &options,255 DiagnosticManager &diagnostic_manager) {256 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step));257 258 LLDB_LOGF(log,259 "-- [FunctionCaller::GetThreadPlanToCallFunction] Creating "260 "thread plan to call function \"%s\" --",261 m_name.c_str());262 263 // FIXME: Use the errors Stream for better error reporting.264 Thread *thread = exe_ctx.GetThreadPtr();265 if (thread == nullptr) {266 diagnostic_manager.PutString(267 lldb::eSeverityError, "Can't call a function without a valid thread.");268 return nullptr;269 }270 271 // Okay, now run the function:272 273 Address wrapper_address(m_jit_start_addr);274 275 lldb::addr_t args = {args_addr};276 277 lldb::ThreadPlanSP new_plan_sp(new ThreadPlanCallFunction(278 *thread, wrapper_address, CompilerType(), args, options));279 new_plan_sp->SetIsControllingPlan(true);280 new_plan_sp->SetOkayToDiscard(false);281 return new_plan_sp;282}283 284bool FunctionCaller::FetchFunctionResults(ExecutionContext &exe_ctx,285 lldb::addr_t args_addr,286 Value &ret_value) {287 // Read the return value - it is the last field in the struct:288 // FIXME: How does clang tell us there's no return value? We need to handle289 // that case.290 // FIXME: Create our ThreadPlanCallFunction with the return CompilerType, and291 // then use GetReturnValueObject292 // to fetch the value. That way we can fetch any values we need.293 294 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step));295 296 LLDB_LOGF(log,297 "-- [FunctionCaller::FetchFunctionResults] Fetching function "298 "results for \"%s\"--",299 m_name.c_str());300 301 Process *process = exe_ctx.GetProcessPtr();302 303 if (process == nullptr)304 return false;305 306 lldb::ProcessSP jit_process_sp(m_jit_process_wp.lock());307 308 if (process != jit_process_sp.get())309 return false;310 311 Status error;312 ret_value.GetScalar() = process->ReadUnsignedIntegerFromMemory(313 args_addr + m_return_offset, m_return_size, 0, error);314 315 if (error.Fail())316 return false;317 318 ret_value.SetCompilerType(m_function_return_type);319 ret_value.SetValueType(Value::ValueType::Scalar);320 return true;321}322 323void FunctionCaller::DeallocateFunctionResults(ExecutionContext &exe_ctx,324 lldb::addr_t args_addr) {325 std::list<lldb::addr_t>::iterator pos;326 pos = llvm::find(m_wrapper_args_addrs, args_addr);327 if (pos != m_wrapper_args_addrs.end())328 m_wrapper_args_addrs.erase(pos);329 330 exe_ctx.GetProcessRef().DeallocateMemory(args_addr);331}332 333lldb::ExpressionResults FunctionCaller::ExecuteFunction(334 ExecutionContext &exe_ctx, lldb::addr_t *args_addr_ptr,335 const EvaluateExpressionOptions &options,336 DiagnosticManager &diagnostic_manager, Value &results) {337 lldb::ExpressionResults return_value = lldb::eExpressionSetupError;338 339 Debugger *debugger =340 exe_ctx.GetTargetPtr() ? &exe_ctx.GetTargetPtr()->GetDebugger() : nullptr;341 Progress progress("Calling function", FunctionName(), {}, debugger);342 343 // FunctionCaller::ExecuteFunction execution is always just to get the344 // result. Unless explicitly asked for, ignore breakpoints and unwind on345 // error.346 const bool enable_debugging =347 exe_ctx.GetTargetPtr() &&348 exe_ctx.GetTargetPtr()->GetDebugUtilityExpression();349 EvaluateExpressionOptions real_options = options;350 real_options.SetDebug(false); // This halts the expression for debugging.351 real_options.SetGenerateDebugInfo(enable_debugging);352 real_options.SetUnwindOnError(!enable_debugging);353 real_options.SetIgnoreBreakpoints(!enable_debugging);354 355 lldb::addr_t args_addr;356 357 if (args_addr_ptr != nullptr)358 args_addr = *args_addr_ptr;359 else360 args_addr = LLDB_INVALID_ADDRESS;361 362 if (CompileFunction(exe_ctx.GetThreadSP(), diagnostic_manager) != 0)363 return lldb::eExpressionSetupError;364 365 if (args_addr == LLDB_INVALID_ADDRESS) {366 if (!InsertFunction(exe_ctx, args_addr, diagnostic_manager))367 return lldb::eExpressionSetupError;368 }369 370 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step));371 372 LLDB_LOGF(log,373 "== [FunctionCaller::ExecuteFunction] Executing function \"%s\" ==",374 m_name.c_str());375 376 lldb::ThreadPlanSP call_plan_sp = GetThreadPlanToCallFunction(377 exe_ctx, args_addr, real_options, diagnostic_manager);378 if (!call_plan_sp)379 return lldb::eExpressionSetupError;380 381 // We need to make sure we record the fact that we are running an expression382 // here otherwise this fact will fail to be recorded when fetching an383 // Objective-C object description384 if (exe_ctx.GetProcessPtr())385 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);386 387 return_value = exe_ctx.GetProcessRef().RunThreadPlan(388 exe_ctx, call_plan_sp, real_options, diagnostic_manager);389 390 if (log) {391 if (return_value != lldb::eExpressionCompleted) {392 LLDB_LOGF(log,393 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "394 "completed abnormally: %s ==",395 m_name.c_str(), toString(return_value).c_str());396 } else {397 LLDB_LOGF(log,398 "== [FunctionCaller::ExecuteFunction] Execution of \"%s\" "399 "completed normally ==",400 m_name.c_str());401 }402 }403 404 if (exe_ctx.GetProcessPtr())405 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);406 407 if (args_addr_ptr != nullptr)408 *args_addr_ptr = args_addr;409 410 if (return_value != lldb::eExpressionCompleted)411 return return_value;412 413 FetchFunctionResults(exe_ctx, args_addr, results);414 415 if (args_addr_ptr == nullptr)416 DeallocateFunctionResults(exe_ctx, args_addr);417 418 return lldb::eExpressionCompleted;419}420