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//===-- LLVMUserExpression.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Expression/LLVMUserExpression.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Expression/ExpressionVariable.h"
#include "lldb/Expression/IRExecutionUnit.h"
#include "lldb/Expression/IRInterpreter.h"
#include "lldb/Expression/Materializer.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Symbol/Type.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlan.h"
#include "lldb/Target/ThreadPlanCallUserExpression.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/StreamString.h"
using namespace lldb_private;
char LLVMUserExpression::ID;
LLVMUserExpression::LLVMUserExpression(ExecutionContextScope &exe_scope,
llvm::StringRef expr,
llvm::StringRef prefix,
lldb::LanguageType language,
ResultType desired_type,
const EvaluateExpressionOptions &options)
: UserExpression(exe_scope, expr, prefix, language, desired_type, options),
m_stack_frame_bottom(LLDB_INVALID_ADDRESS),
m_stack_frame_top(LLDB_INVALID_ADDRESS), m_allow_cxx(false),
m_allow_objc(false), m_transformed_text(), m_execution_unit_sp(),
m_materializer_up(), m_jit_module_wp(), m_can_interpret(false),
m_materialized_address(LLDB_INVALID_ADDRESS) {}
LLVMUserExpression::~LLVMUserExpression() {
if (m_target) {
lldb::ModuleSP jit_module_sp(m_jit_module_wp.lock());
if (jit_module_sp)
m_target->GetImages().Remove(jit_module_sp);
}
}
lldb::ExpressionResults
LLVMUserExpression::DoExecute(DiagnosticManager &diagnostic_manager,
ExecutionContext &exe_ctx,
const EvaluateExpressionOptions &options,
lldb::UserExpressionSP &shared_ptr_to_me,
lldb::ExpressionVariableSP &result) {
// The expression log is quite verbose, and if you're just tracking the
// execution of the expression, it's quite convenient to have these logs come
// out with the STEP log as well.
Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_EXPRESSIONS |
LIBLLDB_LOG_STEP));
if (m_jit_start_addr == LLDB_INVALID_ADDRESS && !m_can_interpret) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"Expression can't be run, because there is no JIT compiled function");
return lldb::eExpressionSetupError;
}
lldb::addr_t struct_address = LLDB_INVALID_ADDRESS;
if (!PrepareToExecuteJITExpression(diagnostic_manager, exe_ctx,
struct_address)) {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"errored out in %s, couldn't PrepareToExecuteJITExpression",
__FUNCTION__);
return lldb::eExpressionSetupError;
}
lldb::addr_t function_stack_bottom = LLDB_INVALID_ADDRESS;
lldb::addr_t function_stack_top = LLDB_INVALID_ADDRESS;
if (m_can_interpret) {
llvm::Module *module = m_execution_unit_sp->GetModule();
llvm::Function *function = m_execution_unit_sp->GetFunction();
if (!module || !function) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"supposed to interpret, but nothing is there");
return lldb::eExpressionSetupError;
}
Status interpreter_error;
std::vector<lldb::addr_t> args;
if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"errored out in %s, couldn't AddArguments",
__FUNCTION__);
return lldb::eExpressionSetupError;
}
function_stack_bottom = m_stack_frame_bottom;
function_stack_top = m_stack_frame_top;
IRInterpreter::Interpret(*module, *function, args, *m_execution_unit_sp,
interpreter_error, function_stack_bottom,
function_stack_top, exe_ctx);
if (!interpreter_error.Success()) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"supposed to interpret, but failed: %s",
interpreter_error.AsCString());
return lldb::eExpressionDiscarded;
}
} else {
if (!exe_ctx.HasThreadScope()) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"%s called with no thread selected",
__FUNCTION__);
return lldb::eExpressionSetupError;
}
// Store away the thread ID for error reporting, in case it exits
// during execution:
lldb::tid_t expr_thread_id = exe_ctx.GetThreadRef().GetID();
Address wrapper_address(m_jit_start_addr);
std::vector<lldb::addr_t> args;
if (!AddArguments(exe_ctx, args, struct_address, diagnostic_manager)) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"errored out in %s, couldn't AddArguments",
__FUNCTION__);
return lldb::eExpressionSetupError;
}
lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallUserExpression(
exe_ctx.GetThreadRef(), wrapper_address, args, options,
shared_ptr_to_me));
StreamString ss;
if (!call_plan_sp || !call_plan_sp->ValidatePlan(&ss)) {
diagnostic_manager.PutString(eDiagnosticSeverityError, ss.GetString());
return lldb::eExpressionSetupError;
}
ThreadPlanCallUserExpression *user_expression_plan =
static_cast<ThreadPlanCallUserExpression *>(call_plan_sp.get());
lldb::addr_t function_stack_pointer =
user_expression_plan->GetFunctionStackPointer();
function_stack_bottom = function_stack_pointer - HostInfo::GetPageSize();
function_stack_top = function_stack_pointer;
LLDB_LOGF(log,
"-- [UserExpression::Execute] Execution of expression begins --");
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(true);
lldb::ExpressionResults execution_result =
exe_ctx.GetProcessRef().RunThreadPlan(exe_ctx, call_plan_sp, options,
diagnostic_manager);
if (exe_ctx.GetProcessPtr())
exe_ctx.GetProcessPtr()->SetRunningUserExpression(false);
LLDB_LOGF(log, "-- [UserExpression::Execute] Execution of expression "
"completed --");
if (execution_result == lldb::eExpressionInterrupted ||
execution_result == lldb::eExpressionHitBreakpoint) {
const char *error_desc = nullptr;
if (call_plan_sp) {
lldb::StopInfoSP real_stop_info_sp = call_plan_sp->GetRealStopInfo();
if (real_stop_info_sp)
error_desc = real_stop_info_sp->GetDescription();
}
if (error_desc)
diagnostic_manager.Printf(eDiagnosticSeverityError,
"Execution was interrupted, reason: %s.",
error_desc);
else
diagnostic_manager.PutString(eDiagnosticSeverityError,
"Execution was interrupted.");
if ((execution_result == lldb::eExpressionInterrupted &&
options.DoesUnwindOnError()) ||
(execution_result == lldb::eExpressionHitBreakpoint &&
options.DoesIgnoreBreakpoints()))
diagnostic_manager.AppendMessageToDiagnostic(
"The process has been returned to the state before expression "
"evaluation.");
else {
if (execution_result == lldb::eExpressionHitBreakpoint)
user_expression_plan->TransferExpressionOwnership();
diagnostic_manager.AppendMessageToDiagnostic(
"The process has been left at the point where it was "
"interrupted, "
"use \"thread return -x\" to return to the state before "
"expression evaluation.");
}
return execution_result;
} else if (execution_result == lldb::eExpressionStoppedForDebug) {
diagnostic_manager.PutString(
eDiagnosticSeverityRemark,
"Execution was halted at the first instruction of the expression "
"function because \"debug\" was requested.\n"
"Use \"thread return -x\" to return to the state before expression "
"evaluation.");
return execution_result;
} else if (execution_result == lldb::eExpressionThreadVanished) {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"Couldn't complete execution; the thread "
"on which the expression was being run: 0x%" PRIx64
" exited during its execution.",
expr_thread_id);
return execution_result;
} else if (execution_result != lldb::eExpressionCompleted) {
diagnostic_manager.Printf(
eDiagnosticSeverityError, "Couldn't execute function; result was %s",
Process::ExecutionResultAsCString(execution_result));
return execution_result;
}
}
if (FinalizeJITExecution(diagnostic_manager, exe_ctx, result,
function_stack_bottom, function_stack_top)) {
return lldb::eExpressionCompleted;
} else {
return lldb::eExpressionResultUnavailable;
}
}
bool LLVMUserExpression::FinalizeJITExecution(
DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
lldb::ExpressionVariableSP &result, lldb::addr_t function_stack_bottom,
lldb::addr_t function_stack_top) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
LLDB_LOGF(log, "-- [UserExpression::FinalizeJITExecution] Dematerializing "
"after execution --");
if (!m_dematerializer_sp) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"Couldn't apply expression side effects : no "
"dematerializer is present");
return false;
}
Status dematerialize_error;
m_dematerializer_sp->Dematerialize(dematerialize_error, function_stack_bottom,
function_stack_top);
if (!dematerialize_error.Success()) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"Couldn't apply expression side effects : %s",
dematerialize_error.AsCString("unknown error"));
return false;
}
result =
GetResultAfterDematerialization(exe_ctx.GetBestExecutionContextScope());
if (result)
result->TransferAddress();
m_dematerializer_sp.reset();
return true;
}
bool LLVMUserExpression::PrepareToExecuteJITExpression(
DiagnosticManager &diagnostic_manager, ExecutionContext &exe_ctx,
lldb::addr_t &struct_address) {
lldb::TargetSP target;
lldb::ProcessSP process;
lldb::StackFrameSP frame;
if (!LockAndCheckContext(exe_ctx, target, process, frame)) {
diagnostic_manager.PutString(
eDiagnosticSeverityError,
"The context has changed before we could JIT the expression!");
return false;
}
if (m_jit_start_addr != LLDB_INVALID_ADDRESS || m_can_interpret) {
if (m_materialized_address == LLDB_INVALID_ADDRESS) {
Status alloc_error;
IRMemoryMap::AllocationPolicy policy =
m_can_interpret ? IRMemoryMap::eAllocationPolicyHostOnly
: IRMemoryMap::eAllocationPolicyMirror;
const bool zero_memory = false;
m_materialized_address = m_execution_unit_sp->Malloc(
m_materializer_up->GetStructByteSize(),
m_materializer_up->GetStructAlignment(),
lldb::ePermissionsReadable | lldb::ePermissionsWritable, policy,
zero_memory, alloc_error);
if (!alloc_error.Success()) {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"Couldn't allocate space for materialized struct: %s",
alloc_error.AsCString());
return false;
}
}
struct_address = m_materialized_address;
if (m_can_interpret && m_stack_frame_bottom == LLDB_INVALID_ADDRESS) {
Status alloc_error;
const size_t stack_frame_size = 512 * 1024;
const bool zero_memory = false;
m_stack_frame_bottom = m_execution_unit_sp->Malloc(
stack_frame_size, 8,
lldb::ePermissionsReadable | lldb::ePermissionsWritable,
IRMemoryMap::eAllocationPolicyHostOnly, zero_memory, alloc_error);
m_stack_frame_top = m_stack_frame_bottom + stack_frame_size;
if (!alloc_error.Success()) {
diagnostic_manager.Printf(
eDiagnosticSeverityError,
"Couldn't allocate space for the stack frame: %s",
alloc_error.AsCString());
return false;
}
}
Status materialize_error;
m_dematerializer_sp = m_materializer_up->Materialize(
frame, *m_execution_unit_sp, struct_address, materialize_error);
if (!materialize_error.Success()) {
diagnostic_manager.Printf(eDiagnosticSeverityError,
"Couldn't materialize: %s",
materialize_error.AsCString());
return false;
}
}
return true;
}