378 lines · cpp
1//===-- LLVMUserExpression.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/LLVMUserExpression.h"10#include "lldb/Core/Module.h"11#include "lldb/Expression/DiagnosticManager.h"12#include "lldb/Expression/ExpressionVariable.h"13#include "lldb/Expression/IRExecutionUnit.h"14#include "lldb/Expression/IRInterpreter.h"15#include "lldb/Expression/Materializer.h"16#include "lldb/Host/HostInfo.h"17#include "lldb/Symbol/Block.h"18#include "lldb/Symbol/Function.h"19#include "lldb/Symbol/ObjectFile.h"20#include "lldb/Symbol/SymbolVendor.h"21#include "lldb/Symbol/Type.h"22#include "lldb/Symbol/VariableList.h"23#include "lldb/Target/ABI.h"24#include "lldb/Target/ExecutionContext.h"25#include "lldb/Target/Process.h"26#include "lldb/Target/StackFrame.h"27#include "lldb/Target/Target.h"28#include "lldb/Target/ThreadPlan.h"29#include "lldb/Target/ThreadPlanCallUserExpression.h"30#include "lldb/Utility/ConstString.h"31#include "lldb/Utility/ErrorMessages.h"32#include "lldb/Utility/LLDBLog.h"33#include "lldb/Utility/Log.h"34#include "lldb/Utility/StreamString.h"35#include "lldb/ValueObject/ValueObjectConstResult.h"36 37using namespace lldb;38using namespace lldb_private;39 40char LLVMUserExpression::ID;41 42LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope,43 llvm::StringRef expr,44 llvm::StringRef prefix,45 SourceLanguage language,46 ResultType desired_type,47 const EvaluateExpressionOptions &options)48 : UserExpression(exe_scope, expr, prefix, language, desired_type, options),49 m_stack_frame_bottom(LLDB_INVALID_ADDRESS),50 m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false),51 m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(),52 m_materializer_up(), m_jit_module_wp(), m_target(nullptr),53 m_can_interpret(false), m_materialized_address(LLDB_INVALID_ADDRESS) {}54 55LLVMUserExpression::~LLVMUserExpression() {56 if (m_target) {57 lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());58 if (jit_module_sp)59 m_target->GetImages().Remove(jit_module_sp);60 }61}62 63lldb::ExpressionResults64LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager,65 ExecutionContext &exe_ctx,66 const EvaluateExpressionOptions &options,67 lldb::UserExpressionSP &shared_ptr_to_me,68 lldb::ExpressionVariableSP &result) {69 // The expression log is quite verbose, and if you're just tracking the70 // execution of the expression, it's quite convenient to have these logs come71 // out with the STEP log as well.72 Log *log(GetLog(LLDBLog::Expressions | LLDBLog::Step));73 74 if (m_jit_start_addr == LLDB_INVALID_ADDRESS && !m_can_interpret) {75 diagnostic_manager.PutString(76 lldb::eSeverityError,77 "Expression can't be run, because there is no JIT compiled function");78 return lldb::eExpressionSetupError;79 }80 81 lldb::addr_t struct_address = LLDB_INVALID_ADDRESS;82 83 if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx,84 struct_address)) {85 diagnostic_manager.Printf(86 lldb::eSeverityError,87 "errored out in %s, couldn't PrepareToExecuteJITExpression",88 __FUNCTION__);89 return lldb::eExpressionSetupError;90 }91 92 lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS;93 lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS;94 95 if (m_can_interpret) {96 llvm::Module *module = m_execution_unit_sp->GetModule();97 llvm::Function *function = m_execution_unit_sp->GetFunction();98 99 if (!module || !function) {100 diagnostic_manager.PutString(101 lldb::eSeverityError, "supposed to interpret, but nothing is there");102 return lldb::eExpressionSetupError;103 }104 105 Status interpreter_error;106 107 std::vector<lldb::addr_t> args;108 109 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {110 diagnostic_manager.Printf(lldb::eSeverityError,111 "errored out in %s, couldn't AddArguments",112 __FUNCTION__);113 return lldb::eExpressionSetupError;114 }115 116 function_stack_bottom = m_stack_frame_bottom;117 function_stack_top = m_stack_frame_top;118 119 IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp,120 interpreter_error, function_stack_bottom,121 function_stack_top, exe_ctx, options.GetTimeout());122 123 if (!interpreter_error.Success()) {124 diagnostic_manager.Printf(lldb::eSeverityError,125 "supposed to interpret, but failed: %s",126 interpreter_error.AsCString());127 return lldb::eExpressionDiscarded;128 }129 } else {130 if (!exe_ctx.HasThreadScope()) {131 diagnostic_manager.Printf(lldb::eSeverityError,132 "%s called with no thread selected",133 __FUNCTION__);134 return lldb::eExpressionSetupError;135 }136 137 // Store away the thread ID for error reporting, in case it exits138 // during execution:139 lldb::tid_t expr_thread_id = exe_ctx.GetThreadRef().GetID();140 141 Address wrapper_address(m_jit_start_addr);142 143 std::vector<lldb::addr_t> args;144 145 if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {146 diagnostic_manager.Printf(lldb::eSeverityError,147 "errored out in %s, couldn't AddArguments",148 __FUNCTION__);149 return lldb::eExpressionSetupError;150 }151 152 lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression(153 exe_ctx.GetThreadRef(), wrapper_address, args, options,154 shared_ptr_to_me));155 156 StreamString ss;157 if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) {158 diagnostic_manager.PutString(lldb::eSeverityError, ss.GetString());159 return lldb::eExpressionSetupError;160 }161 162 ThreadPlanCallUserExpression *user_expression_plan =163 static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get());164 165 lldb::addr_t function_stack_pointer =166 user_expression_plan->GetFunctionStackPointer();167 168 function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize();169 function_stack_top = function_stack_pointer;170 171 LLDB_LOGF(log,172 "-- [UserExpression::Execute] Execution of expression begins --");173 174 if (exe_ctx.GetProcessPtr())175 exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);176 177 lldb::ExpressionResults execution_result =178 exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options,179 diagnostic_manager);180 181 if (exe_ctx.GetProcessPtr())182 exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);183 184 LLDB_LOGF(log, "-- [UserExpression::Execute] Execution of expression "185 "completed --");186 187 if (execution_result == lldb::eExpressionInterrupted ||188 execution_result == lldb::eExpressionHitBreakpoint) {189 const char *error_desc = nullptr;190 const char *explanation = execution_result == lldb::eExpressionInterrupted191 ? "was interrupted"192 : "hit a breakpoint";193 194 if (user_expression_plan) {195 if (auto real_stop_info_sp = user_expression_plan->GetRealStopInfo())196 error_desc = real_stop_info_sp->GetDescription();197 }198 199 if (error_desc)200 diagnostic_manager.Printf(lldb::eSeverityError,201 "Expression execution %s: %s.", explanation,202 error_desc);203 else204 diagnostic_manager.Printf(lldb::eSeverityError,205 "Expression execution %s.", explanation);206 207 if ((execution_result == lldb::eExpressionInterrupted &&208 options.DoesUnwindOnError()) ||209 (execution_result == lldb::eExpressionHitBreakpoint &&210 options.DoesIgnoreBreakpoints()))211 diagnostic_manager.AppendMessageToDiagnostic(212 "The process has been returned to the state before expression "213 "evaluation.");214 else {215 if (execution_result == lldb::eExpressionHitBreakpoint)216 user_expression_plan->TransferExpressionOwnership();217 diagnostic_manager.AppendMessageToDiagnostic(218 "The process has been left at the point where it was "219 "interrupted, use \"thread return -x\" to return to the state "220 "before expression evaluation.");221 }222 223 return execution_result;224 }225 226 if (execution_result == lldb::eExpressionStoppedForDebug) {227 diagnostic_manager.PutString(228 lldb::eSeverityInfo,229 "Expression execution was halted at the first instruction of the "230 "expression function because \"debug\" was requested.\n"231 "Use \"thread return -x\" to return to the state before expression "232 "evaluation.");233 return execution_result;234 }235 236 if (execution_result == lldb::eExpressionThreadVanished) {237 diagnostic_manager.Printf(lldb::eSeverityError,238 "Couldn't execute expression: the thread on "239 "which the expression was being run (0x%" PRIx64240 ") exited during its execution.",241 expr_thread_id);242 return execution_result;243 }244 245 if (execution_result != lldb::eExpressionCompleted) {246 diagnostic_manager.Printf(lldb::eSeverityError,247 "Couldn't execute expression: result was %s",248 toString(execution_result).c_str());249 return execution_result;250 }251 }252 253 if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result,254 function_stack_bottom, function_stack_top)) {255 return lldb::eExpressionCompleted;256 }257 258 return lldb::eExpressionResultUnavailable;259}260 261bool LLVMUserExpression::FinalizeJITExecution(262 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,263 lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom,264 lldb::addr_t function_stack_top) {265 Log *log = GetLog(LLDBLog::Expressions);266 267 LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing "268 "after execution --");269 270 if (!m_dematerializer_sp) {271 diagnostic_manager.Printf(lldb::eSeverityError,272 "Couldn't apply expression side effects : no "273 "dematerializer is present");274 return false;275 }276 277 Status dematerialize_error;278 279 m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom,280 function_stack_top);281 282 if (!dematerialize_error.Success()) {283 diagnostic_manager.Printf(lldb::eSeverityError,284 "Couldn't apply expression side effects : %s",285 dematerialize_error.AsCString("unknown error"));286 return false;287 }288 289 result =290 GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope());291 292 if (result)293 result->TransferAddress();294 295 m_dematerializer_sp.reset();296 297 return true;298}299 300bool LLVMUserExpression::PrepareToExecuteJITExpression(301 DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,302 lldb::addr_t &struct_address) {303 lldb::TargetSP target;304 lldb::ProcessSP process;305 lldb::StackFrameSP frame;306 307 if (!LockAndCheckContext(exe_ctx, target, process, frame)) {308 diagnostic_manager.PutString(309 lldb::eSeverityError,310 "The context has changed before we could JIT the expression!");311 return false;312 }313 314 if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) {315 if (m_materialized_address == LLDB_INVALID_ADDRESS) {316 IRMemoryMap::AllocationPolicy policy =317 m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly318 : IRMemoryMap::eAllocationPolicyMirror;319 320 const bool zero_memory = false;321 if (auto address_or_error = m_execution_unit_sp->Malloc(322 m_materializer_up->GetStructByteSize(),323 m_materializer_up->GetStructAlignment(),324 lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy,325 zero_memory)) {326 m_materialized_address = *address_or_error;327 } else {328 diagnostic_manager.Printf(329 lldb::eSeverityError,330 "Couldn't allocate space for materialized struct: %s",331 toString(address_or_error.takeError()).c_str());332 return false;333 }334 }335 336 struct_address = m_materialized_address;337 338 if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) {339 size_t stack_frame_size = target->GetExprAllocSize();340 if (stack_frame_size == 0) {341 ABISP abi_sp;342 if (process && (abi_sp = process->GetABI()))343 stack_frame_size = abi_sp->GetStackFrameSize();344 else345 stack_frame_size = 512 * 1024;346 }347 348 const bool zero_memory = false;349 if (auto address_or_error = m_execution_unit_sp->Malloc(350 stack_frame_size, 8,351 lldb::ePermissionsReadable | lldb::ePermissionsWritable,352 IRMemoryMap::eAllocationPolicyHostOnly, zero_memory)) {353 m_stack_frame_bottom = *address_or_error;354 m_stack_frame_top = m_stack_frame_bottom + stack_frame_size;355 } else {356 diagnostic_manager.Printf(357 lldb::eSeverityError,358 "Couldn't allocate space for the stack frame: %s",359 toString(address_or_error.takeError()).c_str());360 return false;361 }362 }363 364 Status materialize_error;365 366 m_dematerializer_sp = m_materializer_up->Materialize(367 frame, *m_execution_unit_sp, struct_address, materialize_error);368 369 if (!materialize_error.Success()) {370 diagnostic_manager.Printf(lldb::eSeverityError,371 "Couldn't materialize: %s",372 materialize_error.AsCString());373 return false;374 }375 }376 return true;377}378