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//===-- ThreadPlanStepInRange.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/ThreadPlanStepInRange.h"
#include "lldb/Core/Architecture.h"
#include "lldb/Core/Module.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/SectionLoadList.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlanStepOut.h"
#include "lldb/Target/ThreadPlanStepThrough.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/Utility/Stream.h"
using namespace lldb;
using namespace lldb_private;
uint32_t ThreadPlanStepInRange::s_default_flag_values =
ThreadPlanShouldStopHere::eStepInAvoidNoDebug;
// ThreadPlanStepInRange: Step through a stack range, either stepping over or
// into based on the value of \a type.
ThreadPlanStepInRange::ThreadPlanStepInRange(
Thread &thread, const AddressRange &range,
const SymbolContext &addr_context, lldb::RunMode stop_others,
LazyBool step_in_avoids_code_without_debug_info,
LazyBool step_out_avoids_code_without_debug_info)
: ThreadPlanStepRange(ThreadPlan::eKindStepInRange,
"Step Range stepping in", thread, range, addr_context,
stop_others),
ThreadPlanShouldStopHere(this), m_step_past_prologue(true),
m_virtual_step(false) {
SetCallbacks();
SetFlagsToDefault();
SetupAvoidNoDebug(step_in_avoids_code_without_debug_info,
step_out_avoids_code_without_debug_info);
}
ThreadPlanStepInRange::~ThreadPlanStepInRange() = default;
void ThreadPlanStepInRange::SetupAvoidNoDebug(
LazyBool step_in_avoids_code_without_debug_info,
LazyBool step_out_avoids_code_without_debug_info) {
bool avoid_nodebug = true;
Thread &thread = GetThread();
switch (step_in_avoids_code_without_debug_info) {
case eLazyBoolYes:
avoid_nodebug = true;
break;
case eLazyBoolNo:
avoid_nodebug = false;
break;
case eLazyBoolCalculate:
avoid_nodebug = thread.GetStepInAvoidsNoDebug();
break;
}
if (avoid_nodebug)
GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
else
GetFlags().Clear(ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
switch (step_out_avoids_code_without_debug_info) {
case eLazyBoolYes:
avoid_nodebug = true;
break;
case eLazyBoolNo:
avoid_nodebug = false;
break;
case eLazyBoolCalculate:
avoid_nodebug = thread.GetStepOutAvoidsNoDebug();
break;
}
if (avoid_nodebug)
GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
else
GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
}
void ThreadPlanStepInRange::GetDescription(Stream *s,
lldb::DescriptionLevel level) {
auto PrintFailureIfAny = [&]() {
if (m_status.Success())
return;
s->Printf(" failed (%s)", m_status.AsCString());
};
if (level == lldb::eDescriptionLevelBrief) {
s->Printf("step in");
PrintFailureIfAny();
return;
}
s->Printf("Stepping in");
bool printed_line_info = false;
if (m_addr_context.line_entry.IsValid()) {
s->Printf(" through line ");
m_addr_context.line_entry.DumpStopContext(s, false);
printed_line_info = true;
}
const char *step_into_target = m_step_into_target.AsCString();
if (step_into_target && step_into_target[0] != '\0')
s->Printf(" targeting %s", m_step_into_target.AsCString());
if (!printed_line_info || level == eDescriptionLevelVerbose) {
s->Printf(" using ranges:");
DumpRanges(s);
}
PrintFailureIfAny();
s->PutChar('.');
}
bool ThreadPlanStepInRange::ShouldStop(Event *event_ptr) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log) {
StreamString s;
DumpAddress(s.AsRawOstream(), GetThread().GetRegisterContext()->GetPC(),
GetTarget().GetArchitecture().GetAddressByteSize());
LLDB_LOGF(log, "ThreadPlanStepInRange reached %s.", s.GetData());
}
if (IsPlanComplete())
return true;
m_no_more_plans = false;
if (m_sub_plan_sp && m_sub_plan_sp->IsPlanComplete()) {
if (!m_sub_plan_sp->PlanSucceeded()) {
SetPlanComplete();
m_no_more_plans = true;
return true;
} else
m_sub_plan_sp.reset();
}
if (m_virtual_step) {
// If we've just completed a virtual step, all we need to do is check for a
// ShouldStopHere plan, and otherwise we're done.
// FIXME - This can be both a step in and a step out. Probably should
// record which in the m_virtual_step.
m_sub_plan_sp =
CheckShouldStopHereAndQueueStepOut(eFrameCompareYounger, m_status);
} else {
// Stepping through should be done running other threads in general, since
// we're setting a breakpoint and continuing. So only stop others if we
// are explicitly told to do so.
bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
FrameComparison frame_order = CompareCurrentFrameToStartFrame();
Thread &thread = GetThread();
if (frame_order == eFrameCompareOlder ||
frame_order == eFrameCompareSameParent) {
// If we're in an older frame then we should stop.
//
// A caveat to this is if we think the frame is older but we're actually
// in a trampoline.
// I'm going to make the assumption that you wouldn't RETURN to a
// trampoline. So if we are in a trampoline we think the frame is older
// because the trampoline confused the backtracer.
m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
m_stack_id, false, stop_others, m_status);
if (!m_sub_plan_sp) {
// Otherwise check the ShouldStopHere for step out:
m_sub_plan_sp =
CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
if (log) {
if (m_sub_plan_sp)
LLDB_LOGF(log,
"ShouldStopHere found plan to step out of this frame.");
else
LLDB_LOGF(log, "ShouldStopHere no plan to step out of this frame.");
}
} else if (log) {
LLDB_LOGF(
log, "Thought I stepped out, but in fact arrived at a trampoline.");
}
} else if (frame_order == eFrameCompareEqual && InSymbol()) {
// If we are not in a place we should step through, we're done. One
// tricky bit here is that some stubs don't push a frame, so we have to
// check both the case of a frame that is younger, or the same as this
// frame. However, if the frame is the same, and we are still in the
// symbol we started in, the we don't need to do this. This first check
// isn't strictly necessary, but it is more efficient.
// If we're still in the range, keep going, either by running to the next
// branch breakpoint, or by stepping.
if (InRange()) {
SetNextBranchBreakpoint();
return false;
}
SetPlanComplete();
m_no_more_plans = true;
return true;
}
// If we get to this point, we're not going to use a previously set "next
// branch" breakpoint, so delete it:
ClearNextBranchBreakpoint();
// We may have set the plan up above in the FrameIsOlder section:
if (!m_sub_plan_sp)
m_sub_plan_sp = thread.QueueThreadPlanForStepThrough(
m_stack_id, false, stop_others, m_status);
if (log) {
if (m_sub_plan_sp)
LLDB_LOGF(log, "Found a step through plan: %s",
m_sub_plan_sp->GetName());
else
LLDB_LOGF(log, "No step through plan found.");
}
// If not, give the "should_stop" callback a chance to push a plan to get
// us out of here. But only do that if we actually have stepped in.
if (!m_sub_plan_sp && frame_order == eFrameCompareYounger)
m_sub_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
// If we've stepped in and we are going to stop here, check to see if we
// were asked to run past the prologue, and if so do that.
if (!m_sub_plan_sp && frame_order == eFrameCompareYounger &&
m_step_past_prologue) {
lldb::StackFrameSP curr_frame = thread.GetStackFrameAtIndex(0);
if (curr_frame) {
size_t bytes_to_skip = 0;
lldb::addr_t curr_addr = thread.GetRegisterContext()->GetPC();
Address func_start_address;
SymbolContext sc = curr_frame->GetSymbolContext(eSymbolContextFunction |
eSymbolContextSymbol);
if (sc.function) {
func_start_address = sc.function->GetAddressRange().GetBaseAddress();
if (curr_addr == func_start_address.GetLoadAddress(&GetTarget()))
bytes_to_skip = sc.function->GetPrologueByteSize();
} else if (sc.symbol) {
func_start_address = sc.symbol->GetAddress();
if (curr_addr == func_start_address.GetLoadAddress(&GetTarget()))
bytes_to_skip = sc.symbol->GetPrologueByteSize();
}
if (bytes_to_skip == 0 && sc.symbol) {
const Architecture *arch = GetTarget().GetArchitecturePlugin();
if (arch) {
Address curr_sec_addr;
GetTarget().GetSectionLoadList().ResolveLoadAddress(curr_addr,
curr_sec_addr);
bytes_to_skip = arch->GetBytesToSkip(*sc.symbol, curr_sec_addr);
}
}
if (bytes_to_skip != 0) {
func_start_address.Slide(bytes_to_skip);
log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP);
LLDB_LOGF(log, "Pushing past prologue ");
m_sub_plan_sp = thread.QueueThreadPlanForRunToAddress(
false, func_start_address, true, m_status);
}
}
}
}
if (!m_sub_plan_sp) {
m_no_more_plans = true;
SetPlanComplete();
return true;
} else {
m_no_more_plans = false;
m_sub_plan_sp->SetPrivate(true);
return false;
}
}
void ThreadPlanStepInRange::SetAvoidRegexp(const char *name) {
auto name_ref = llvm::StringRef::withNullAsEmpty(name);
if (m_avoid_regexp_up)
*m_avoid_regexp_up = RegularExpression(name_ref);
else
m_avoid_regexp_up = std::make_unique<RegularExpression>(name_ref);
}
void ThreadPlanStepInRange::SetDefaultFlagValue(uint32_t new_value) {
// TODO: Should we test this for sanity?
ThreadPlanStepInRange::s_default_flag_values = new_value;
}
bool ThreadPlanStepInRange::FrameMatchesAvoidCriteria() {
StackFrame *frame = GetThread().GetStackFrameAtIndex(0).get();
// Check the library list first, as that's cheapest:
bool libraries_say_avoid = false;
FileSpecList libraries_to_avoid(GetThread().GetLibrariesToAvoid());
size_t num_libraries = libraries_to_avoid.GetSize();
if (num_libraries > 0) {
SymbolContext sc(frame->GetSymbolContext(eSymbolContextModule));
FileSpec frame_library(sc.module_sp->GetFileSpec());
if (frame_library) {
for (size_t i = 0; i < num_libraries; i++) {
const FileSpec &file_spec(libraries_to_avoid.GetFileSpecAtIndex(i));
if (FileSpec::Match(file_spec, frame_library)) {
libraries_say_avoid = true;
break;
}
}
}
}
if (libraries_say_avoid)
return true;
const RegularExpression *avoid_regexp_to_use = m_avoid_regexp_up.get();
if (avoid_regexp_to_use == nullptr)
avoid_regexp_to_use = GetThread().GetSymbolsToAvoidRegexp();
if (avoid_regexp_to_use != nullptr) {
SymbolContext sc = frame->GetSymbolContext(
eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
if (sc.symbol != nullptr) {
const char *frame_function_name =
sc.GetFunctionName(Mangled::ePreferDemangledWithoutArguments)
.GetCString();
if (frame_function_name) {
llvm::SmallVector<llvm::StringRef, 2> matches;
bool return_value =
avoid_regexp_to_use->Execute(frame_function_name, &matches);
if (return_value && matches.size() > 1) {
std::string match = matches[1].str();
LLDB_LOGF(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP),
"Stepping out of function \"%s\" because it matches "
"the avoid regexp \"%s\" - match substring: \"%s\".",
frame_function_name,
avoid_regexp_to_use->GetText().str().c_str(),
match.c_str());
}
return return_value;
}
}
}
return false;
}
bool ThreadPlanStepInRange::DefaultShouldStopHereCallback(
ThreadPlan *current_plan, Flags &flags, FrameComparison operation,
Status &status, void *baton) {
bool should_stop_here = true;
StackFrame *frame = current_plan->GetThread().GetStackFrameAtIndex(0).get();
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
// First see if the ThreadPlanShouldStopHere default implementation thinks we
// should get out of here:
should_stop_here = ThreadPlanShouldStopHere::DefaultShouldStopHereCallback(
current_plan, flags, operation, status, baton);
if (!should_stop_here)
return false;
if (should_stop_here && current_plan->GetKind() == eKindStepInRange &&
operation == eFrameCompareYounger) {
ThreadPlanStepInRange *step_in_range_plan =
static_cast<ThreadPlanStepInRange *>(current_plan);
if (step_in_range_plan->m_step_into_target) {
SymbolContext sc = frame->GetSymbolContext(
eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
if (sc.symbol != nullptr) {
// First try an exact match, since that's cheap with ConstStrings.
// Then do a strstr compare.
if (step_in_range_plan->m_step_into_target == sc.GetFunctionName()) {
should_stop_here = true;
} else {
const char *target_name =
step_in_range_plan->m_step_into_target.AsCString();
const char *function_name = sc.GetFunctionName().AsCString();
if (function_name == nullptr)
should_stop_here = false;
else if (strstr(function_name, target_name) == nullptr)
should_stop_here = false;
}
if (log && !should_stop_here)
LLDB_LOGF(log,
"Stepping out of frame %s which did not match step into "
"target %s.",
sc.GetFunctionName().AsCString(),
step_in_range_plan->m_step_into_target.AsCString());
}
}
if (should_stop_here) {
ThreadPlanStepInRange *step_in_range_plan =
static_cast<ThreadPlanStepInRange *>(current_plan);
// Don't log the should_step_out here, it's easier to do it in
// FrameMatchesAvoidCriteria.
should_stop_here = !step_in_range_plan->FrameMatchesAvoidCriteria();
}
}
return should_stop_here;
}
bool ThreadPlanStepInRange::DoPlanExplainsStop(Event *event_ptr) {
// We always explain a stop. Either we've just done a single step, in which
// case we'll do our ordinary processing, or we stopped for some reason that
// isn't handled by our sub-plans, in which case we want to just stop right
// away. In general, we don't want to mark the plan as complete for
// unexplained stops. For instance, if you step in to some code with no debug
// info, so you step out and in the course of that hit a breakpoint, then you
// want to stop & show the user the breakpoint, but not unship the step in
// plan, since you still may want to complete that plan when you continue.
// This is particularly true when doing "step in to target function."
// stepping.
//
// The only variation is that if we are doing "step by running to next
// branch" in which case if we hit our branch breakpoint we don't set the
// plan to complete.
bool return_value = false;
if (m_virtual_step) {
return_value = true;
} else {
StopInfoSP stop_info_sp = GetPrivateStopInfo();
if (stop_info_sp) {
StopReason reason = stop_info_sp->GetStopReason();
if (reason == eStopReasonBreakpoint) {
if (NextRangeBreakpointExplainsStop(stop_info_sp)) {
return_value = true;
}
} else if (IsUsuallyUnexplainedStopReason(reason)) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log)
log->PutCString("ThreadPlanStepInRange got asked if it explains the "
"stop for some reason other than step.");
return_value = false;
} else {
return_value = true;
}
} else
return_value = true;
}
return return_value;
}
bool ThreadPlanStepInRange::DoWillResume(lldb::StateType resume_state,
bool current_plan) {
m_virtual_step = false;
if (resume_state == eStateStepping && current_plan) {
Thread &thread = GetThread();
// See if we are about to step over a virtual inlined call.
bool step_without_resume = thread.DecrementCurrentInlinedDepth();
if (step_without_resume) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
LLDB_LOGF(log,
"ThreadPlanStepInRange::DoWillResume: returning false, "
"inline_depth: %d",
thread.GetCurrentInlinedDepth());
SetStopInfo(StopInfo::CreateStopReasonToTrace(thread));
// FIXME: Maybe it would be better to create a InlineStep stop reason, but
// then
// the whole rest of the world would have to handle that stop reason.
m_virtual_step = true;
}
return !step_without_resume;
}
return true;
}
bool ThreadPlanStepInRange::IsVirtualStep() { return m_virtual_step; }