//===-- ThreadPlanCallFunction.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/Target/ThreadPlanCallFunction.h"
#include "lldb/Breakpoint/Breakpoint.h"
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/DumpRegisterValue.h"
#include "lldb/Core/Module.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Target/ABI.h"
#include "lldb/Target/LanguageRuntime.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlanRunToAddress.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Stream.h"
#include <memory>
using namespace lldb;
using namespace lldb_private;
// ThreadPlanCallFunction: Plan to call a single function
bool ThreadPlanCallFunction::ConstructorSetup(
Thread &thread, ABI *&abi, lldb::addr_t &start_load_addr,
lldb::addr_t &function_load_addr) {
SetIsControllingPlan(true);
SetOkayToDiscard(false);
SetPrivate(true);
ProcessSP process_sp(thread.GetProcess());
if (!process_sp)
return false;
abi = process_sp->GetABI().get();
if (!abi)
return false;
Log *log = GetLog(LLDBLog::Step);
SetBreakpoints();
m_function_sp = thread.GetRegisterContext()->GetSP() - abi->GetRedZoneSize();
// If we can't read memory at the point of the process where we are planning
// to put our function, we're not going to get any further...
Status error;
process_sp->ReadUnsignedIntegerFromMemory(m_function_sp, 4, 0, error);
if (!error.Success()) {
m_constructor_errors.Printf(
"Trying to put the stack in unreadable memory at: 0x%" PRIx64 ".",
m_function_sp);
LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this),
m_constructor_errors.GetData());
return false;
}
llvm::Expected<Address> start_address = GetTarget().GetEntryPointAddress();
if (!start_address) {
m_constructor_errors.Printf(
"%s", llvm::toString(start_address.takeError()).c_str());
LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this),
m_constructor_errors.GetData());
return false;
}
m_start_addr = *start_address;
start_load_addr = m_start_addr.GetLoadAddress(&GetTarget());
// Checkpoint the thread state so we can restore it later.
if (log && log->GetVerbose())
ReportRegisterState("About to checkpoint thread before function call. "
"Original register state was:");
if (!thread.CheckpointThreadState(m_stored_thread_state)) {
m_constructor_errors.Printf("Setting up ThreadPlanCallFunction, failed to "
"checkpoint thread state.");
LLDB_LOGF(log, "ThreadPlanCallFunction(%p): %s.", static_cast<void *>(this),
m_constructor_errors.GetData());
return false;
}
function_load_addr = m_function_addr.GetLoadAddress(&GetTarget());
return true;
}
ThreadPlanCallFunction::ThreadPlanCallFunction(
Thread &thread, const Address &function, const CompilerType &return_type,
llvm::ArrayRef<addr_t> args, const EvaluateExpressionOptions &options)
: ThreadPlan(ThreadPlan::eKindCallFunction, "Call function plan", thread,
eVoteNoOpinion, eVoteNoOpinion),
m_valid(false), m_stop_other_threads(options.GetStopOthers()),
m_unwind_on_error(options.DoesUnwindOnError()),
m_ignore_breakpoints(options.DoesIgnoreBreakpoints()),
m_debug_execution(options.GetDebug()),
m_trap_exceptions(options.GetTrapExceptions()), m_function_addr(function),
m_function_sp(0), m_takedown_done(false),
m_should_clear_objc_exception_bp(false),
m_should_clear_cxx_exception_bp(false),
m_stop_address(LLDB_INVALID_ADDRESS), m_return_type(return_type) {
lldb::addr_t start_load_addr = LLDB_INVALID_ADDRESS;
lldb::addr_t function_load_addr = LLDB_INVALID_ADDRESS;
ABI *abi = nullptr;
if (!ConstructorSetup(thread, abi, start_load_addr, function_load_addr))
return;
if (!abi->PrepareTrivialCall(thread, m_function_sp, function_load_addr,
start_load_addr, args))
return;
ReportRegisterState("Function call was set up. Register state was:");
m_valid = true;
}
ThreadPlanCallFunction::ThreadPlanCallFunction(
Thread &thread, const Address &function,
const EvaluateExpressionOptions &options)
: ThreadPlan(ThreadPlan::eKindCallFunction, "Call function plan", thread,
eVoteNoOpinion, eVoteNoOpinion),
m_valid(false), m_stop_other_threads(options.GetStopOthers()),
m_unwind_on_error(options.DoesUnwindOnError()),
m_ignore_breakpoints(options.DoesIgnoreBreakpoints()),
m_debug_execution(options.GetDebug()),
m_trap_exceptions(options.GetTrapExceptions()), m_function_addr(function),
m_function_sp(0), m_takedown_done(false),
m_should_clear_objc_exception_bp(false),
m_should_clear_cxx_exception_bp(false),
m_stop_address(LLDB_INVALID_ADDRESS), m_return_type(CompilerType()) {}
ThreadPlanCallFunction::~ThreadPlanCallFunction() {
DoTakedown(PlanSucceeded());
}
void ThreadPlanCallFunction::ReportRegisterState(const char *message) {
Log *log = GetLog(LLDBLog::Step);
if (log && log->GetVerbose()) {
StreamString strm;
RegisterContext *reg_ctx = GetThread().GetRegisterContext().get();
log->PutCString(message);
RegisterValue reg_value;
for (uint32_t reg_idx = 0, num_registers = reg_ctx->GetRegisterCount();
reg_idx < num_registers; ++reg_idx) {
const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(reg_idx);
if (reg_ctx->ReadRegister(reg_info, reg_value)) {
DumpRegisterValue(reg_value, &strm, reg_info, true, false,
eFormatDefault);
strm.EOL();
}
}
log->PutString(strm.GetString());
}
}
void ThreadPlanCallFunction::DoTakedown(bool success) {
Log *log = GetLog(LLDBLog::Step);
if (!m_valid) {
// Don't call DoTakedown if we were never valid to begin with.
LLDB_LOGF(log,
"ThreadPlanCallFunction(%p): Log called on "
"ThreadPlanCallFunction that was never valid.",
static_cast<void *>(this));
return;
}
if (!m_takedown_done) {
Thread &thread = GetThread();
if (success) {
SetReturnValue();
}
LLDB_LOGF(log,
"ThreadPlanCallFunction(%p): DoTakedown called for thread "
"0x%4.4" PRIx64 ", m_valid: %d complete: %d.\n",
static_cast<void *>(this), m_tid, m_valid, IsPlanComplete());
m_takedown_done = true;
m_stop_address =
thread.GetStackFrameAtIndex(0)->GetRegisterContext()->GetPC();
m_real_stop_info_sp = GetPrivateStopInfo();
if (!thread.RestoreRegisterStateFromCheckpoint(m_stored_thread_state)) {
LLDB_LOGF(log,
"ThreadPlanCallFunction(%p): DoTakedown failed to restore "
"register state",
static_cast<void *>(this));
}
SetPlanComplete(success);
ClearBreakpoints();
if (log && log->GetVerbose())
ReportRegisterState("Restoring thread state after function call. "
"Restored register state:");
} else {
LLDB_LOGF(log,
"ThreadPlanCallFunction(%p): DoTakedown called as no-op for "
"thread 0x%4.4" PRIx64 ", m_valid: %d complete: %d.\n",
static_cast<void *>(this), m_tid, m_valid, IsPlanComplete());
}
}
void ThreadPlanCallFunction::DidPop() { DoTakedown(PlanSucceeded()); }
void ThreadPlanCallFunction::GetDescription(Stream *s, DescriptionLevel level) {
if (level == eDescriptionLevelBrief) {
s->Printf("Function call thread plan");
} else {
s->Printf("Thread plan to call 0x%" PRIx64,
m_function_addr.GetLoadAddress(&GetTarget()));
}
}
bool ThreadPlanCallFunction::ValidatePlan(Stream *error) {
if (!m_valid) {
if (error) {
if (m_constructor_errors.GetSize() > 0)
error->PutCString(m_constructor_errors.GetString());
else
error->PutCString("Unknown error");
}
return false;
}
return true;
}
Vote ThreadPlanCallFunction::ShouldReportStop(Event *event_ptr) {
if (m_takedown_done || IsPlanComplete())
return eVoteYes;
else
return ThreadPlan::ShouldReportStop(event_ptr);
}
bool ThreadPlanCallFunction::DoPlanExplainsStop(Event *event_ptr) {
Log *log(GetLog(LLDBLog::Step | LLDBLog::Process));
m_real_stop_info_sp = GetPrivateStopInfo();
// If our subplan knows why we stopped, even if it's done (which would
// forward the question to us) we answer yes.
if (m_subplan_sp && m_subplan_sp->PlanExplainsStop(event_ptr)) {
SetPlanComplete();
return true;
}
// Check if the breakpoint is one of ours.
StopReason stop_reason;
if (!m_real_stop_info_sp)
stop_reason = eStopReasonNone;
else
stop_reason = m_real_stop_info_sp->GetStopReason();
LLDB_LOG(log,
"ThreadPlanCallFunction::PlanExplainsStop: Got stop reason - {0}.",
Thread::StopReasonAsString(stop_reason));
if (stop_reason == eStopReasonBreakpoint && BreakpointsExplainStop())
return true;
// One more quirk here. If this event was from Halt interrupting the target,
// then we should not consider ourselves complete. Return true to
// acknowledge the stop.
if (Process::ProcessEventData::GetInterruptedFromEvent(event_ptr)) {
LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop: The event is an "
"Interrupt, returning true.");
return true;
}
// We control breakpoints separately from other "stop reasons." So first,
// check the case where we stopped for an internal breakpoint, in that case,
// continue on. If it is not an internal breakpoint, consult
// m_ignore_breakpoints.
if (stop_reason == eStopReasonBreakpoint) {
uint64_t break_site_id = m_real_stop_info_sp->GetValue();
BreakpointSiteSP bp_site_sp;
bp_site_sp = m_process.GetBreakpointSiteList().FindByID(break_site_id);
if (bp_site_sp) {
uint32_t num_owners = bp_site_sp->GetNumberOfOwners();
bool is_internal = true;
for (uint32_t i = 0; i < num_owners; i++) {
Breakpoint &bp = bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint();
LLDB_LOGF(log,
"ThreadPlanCallFunction::PlanExplainsStop: hit "
"breakpoint %d while calling function",
bp.GetID());
if (!bp.IsInternal()) {
is_internal = false;
break;
}
}
if (is_internal) {
LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop hit an "
"internal breakpoint, not stopping.");
return false;
}
}
if (m_ignore_breakpoints) {
LLDB_LOGF(log,
"ThreadPlanCallFunction::PlanExplainsStop: we are ignoring "
"breakpoints, overriding breakpoint stop info ShouldStop, "
"returning true");
m_real_stop_info_sp->OverrideShouldStop(false);
return true;
} else {
LLDB_LOGF(log, "ThreadPlanCallFunction::PlanExplainsStop: we are not "
"ignoring breakpoints, overriding breakpoint stop info "
"ShouldStop, returning true");
m_real_stop_info_sp->OverrideShouldStop(true);
return false;
}
} else if (!m_unwind_on_error) {
// If we don't want to discard this plan, than any stop we don't understand
// should be propagated up the stack.
return false;
} else {
// If the subplan is running, any crashes are attributable to us. If we
// want to discard the plan, then we say we explain the stop but if we are
// going to be discarded, let whoever is above us explain the stop. But
// don't discard the plan if the stop would restart itself (for instance if
// it is a signal that is set not to stop. Check that here first. We just
// say we explain the stop but aren't done and everything will continue on
// from there.
if (m_real_stop_info_sp &&
m_real_stop_info_sp->ShouldStopSynchronous(event_ptr)) {
SetPlanComplete(false);
return m_subplan_sp ? m_unwind_on_error : false;
} else
return true;
}
}
bool ThreadPlanCallFunction::ShouldStop(Event *event_ptr) {
// We do some computation in DoPlanExplainsStop that may or may not set the
// plan as complete. We need to do that here to make sure our state is
// correct.
DoPlanExplainsStop(event_ptr);
if (IsPlanComplete()) {
ReportRegisterState("Function completed. Register state was:");
return true;
} else {
return false;
}
}
bool ThreadPlanCallFunction::StopOthers() { return m_stop_other_threads; }
StateType ThreadPlanCallFunction::GetPlanRunState() { return eStateRunning; }
void ThreadPlanCallFunction::DidPush() {
//#define SINGLE_STEP_EXPRESSIONS
// Now set the thread state to "no reason" so we don't run with whatever
// signal was outstanding... Wait till the plan is pushed so we aren't
// changing the stop info till we're about to run.
GetThread().SetStopInfoToNothing();
#ifndef SINGLE_STEP_EXPRESSIONS
Thread &thread = GetThread();
m_subplan_sp = std::make_shared<ThreadPlanRunToAddress>(thread, m_start_addr,
m_stop_other_threads);
thread.QueueThreadPlan(m_subplan_sp, false);
m_subplan_sp->SetPrivate(true);
#endif
}
bool ThreadPlanCallFunction::WillStop() { return true; }
bool ThreadPlanCallFunction::MischiefManaged() {
Log *log = GetLog(LLDBLog::Step);
if (IsPlanComplete()) {
LLDB_LOGF(log, "ThreadPlanCallFunction(%p): Completed call function plan.",
static_cast<void *>(this));
ThreadPlan::MischiefManaged();
return true;
} else {
return false;
}
}
void ThreadPlanCallFunction::SetBreakpoints() {
if (m_trap_exceptions) {
m_cxx_language_runtime =
m_process.GetLanguageRuntime(eLanguageTypeC_plus_plus);
m_objc_language_runtime = m_process.GetLanguageRuntime(eLanguageTypeObjC);
if (m_cxx_language_runtime) {
m_should_clear_cxx_exception_bp =
!m_cxx_language_runtime->ExceptionBreakpointsAreSet();
m_cxx_language_runtime->SetExceptionBreakpoints();
}
if (m_objc_language_runtime) {
m_should_clear_objc_exception_bp =
!m_objc_language_runtime->ExceptionBreakpointsAreSet();
m_objc_language_runtime->SetExceptionBreakpoints();
}
}
}
void ThreadPlanCallFunction::ClearBreakpoints() {
if (m_trap_exceptions) {
if (m_cxx_language_runtime && m_should_clear_cxx_exception_bp)
m_cxx_language_runtime->ClearExceptionBreakpoints();
if (m_objc_language_runtime && m_should_clear_objc_exception_bp)
m_objc_language_runtime->ClearExceptionBreakpoints();
}
}
bool ThreadPlanCallFunction::BreakpointsExplainStop() {
StopInfoSP stop_info_sp = GetPrivateStopInfo();
if (m_trap_exceptions) {
if ((m_cxx_language_runtime &&
m_cxx_language_runtime->ExceptionBreakpointsExplainStop(
stop_info_sp)) ||
(m_objc_language_runtime &&
m_objc_language_runtime->ExceptionBreakpointsExplainStop(
stop_info_sp))) {
Log *log = GetLog(LLDBLog::Step);
LLDB_LOGF(log, "ThreadPlanCallFunction::BreakpointsExplainStop - Hit an "
"exception breakpoint, setting plan complete.");
SetPlanComplete(false);
// If the user has set the ObjC language breakpoint, it would normally
// get priority over our internal catcher breakpoint, but in this case we
// can't let that happen, so force the ShouldStop here.
stop_info_sp->OverrideShouldStop(true);
return true;
}
}
return false;
}
void ThreadPlanCallFunction::SetStopOthers(bool new_value) {
m_subplan_sp->SetStopOthers(new_value);
}
void ThreadPlanCallFunction::RestoreThreadState() {
GetThread().RestoreThreadStateFromCheckpoint(m_stored_thread_state);
}
void ThreadPlanCallFunction::SetReturnValue() {
const ABI *abi = m_process.GetABI().get();
if (abi && m_return_type.IsValid()) {
const bool persistent = false;
m_return_valobj_sp =
abi->GetReturnValueObject(GetThread(), m_return_type, persistent);
}
}
