//===-- ThreadPlanStepOverRange.cpp -----------------------------*- C++ -*-===//
//
// 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/ThreadPlanStepOverRange.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/LineTable.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.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/Stream.h"
using namespace lldb_private;
using namespace lldb;
uint32_t ThreadPlanStepOverRange::s_default_flag_values = 0;
// ThreadPlanStepOverRange: Step through a stack range, either stepping over or
// into based on the value of \a type.
ThreadPlanStepOverRange::ThreadPlanStepOverRange(
Thread &thread, const AddressRange &range,
const SymbolContext &addr_context, lldb::RunMode stop_others,
LazyBool step_out_avoids_code_without_debug_info)
: ThreadPlanStepRange(ThreadPlan::eKindStepOverRange,
"Step range stepping over", thread, range,
addr_context, stop_others),
ThreadPlanShouldStopHere(this), m_first_resume(true) {
SetFlagsToDefault();
SetupAvoidNoDebug(step_out_avoids_code_without_debug_info);
}
ThreadPlanStepOverRange::~ThreadPlanStepOverRange() = default;
void ThreadPlanStepOverRange::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 over");
PrintFailureIfAny();
return;
}
s->Printf("Stepping over");
bool printed_line_info = false;
if (m_addr_context.line_entry.IsValid()) {
s->Printf(" line ");
m_addr_context.line_entry.DumpStopContext(s, false);
printed_line_info = true;
}
if (!printed_line_info || level == eDescriptionLevelVerbose) {
s->Printf(" using ranges: ");
DumpRanges(s);
}
PrintFailureIfAny();
s->PutChar('.');
}
void ThreadPlanStepOverRange::SetupAvoidNoDebug(
LazyBool step_out_avoids_code_without_debug_info) {
bool avoid_nodebug = true;
switch (step_out_avoids_code_without_debug_info) {
case eLazyBoolYes:
avoid_nodebug = true;
break;
case eLazyBoolNo:
avoid_nodebug = false;
break;
case eLazyBoolCalculate:
avoid_nodebug = m_thread.GetStepOutAvoidsNoDebug();
break;
}
if (avoid_nodebug)
GetFlags().Set(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
else
GetFlags().Clear(ThreadPlanShouldStopHere::eStepOutAvoidNoDebug);
// Step Over plans should always avoid no-debug on step in. Seems like you
// shouldn't have to say this, but a tail call looks more like a step in that
// a step out, so we want to catch this case.
GetFlags().Set(ThreadPlanShouldStopHere::eStepInAvoidNoDebug);
}
bool ThreadPlanStepOverRange::IsEquivalentContext(
const SymbolContext &context) {
// Match as much as is specified in the m_addr_context: This is a fairly
// loose sanity check. Note, sometimes the target doesn't get filled in so I
// left out the target check. And sometimes the module comes in as the .o
// file from the inlined range, so I left that out too...
if (m_addr_context.comp_unit) {
if (m_addr_context.comp_unit != context.comp_unit)
return false;
if (m_addr_context.function) {
if (m_addr_context.function != context.function)
return false;
// It is okay to return to a different block of a straight function, we
// only have to be more careful if returning from one inlined block to
// another.
if (m_addr_context.block->GetInlinedFunctionInfo() == nullptr &&
context.block->GetInlinedFunctionInfo() == nullptr)
return true;
return m_addr_context.block == context.block;
}
}
// Fall back to symbol if we have no decision from comp_unit/function/block.
return m_addr_context.symbol && m_addr_context.symbol == context.symbol;
}
bool ThreadPlanStepOverRange::ShouldStop(Event *event_ptr) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
if (log) {
StreamString s;
DumpAddress(
s.AsRawOstream(), m_thread.GetRegisterContext()->GetPC(),
m_thread.CalculateTarget()->GetArchitecture().GetAddressByteSize());
LLDB_LOGF(log, "ThreadPlanStepOverRange reached %s.", s.GetData());
}
// If we're out of the range but in the same frame or in our caller's frame
// then we should stop. When stepping out we only stop others if we are
// forcing running one thread.
bool stop_others = (m_stop_others == lldb::eOnlyThisThread);
ThreadPlanSP new_plan_sp;
FrameComparison frame_order = CompareCurrentFrameToStartFrame();
if (frame_order == eFrameCompareOlder) {
// 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. As below, we step
// through first, and then try to figure out how to get back out again.
new_plan_sp = m_thread.QueueThreadPlanForStepThrough(m_stack_id, false,
stop_others, m_status);
if (new_plan_sp && log)
LLDB_LOGF(log,
"Thought I stepped out, but in fact arrived at a trampoline.");
} else if (frame_order == eFrameCompareYounger) {
// Make sure we really are in a new frame. Do that by unwinding and seeing
// if the start function really is our start function...
for (uint32_t i = 1;; ++i) {
StackFrameSP older_frame_sp = m_thread.GetStackFrameAtIndex(i);
if (!older_frame_sp) {
// We can't unwind the next frame we should just get out of here &
// stop...
break;
}
const SymbolContext &older_context =
older_frame_sp->GetSymbolContext(eSymbolContextEverything);
if (IsEquivalentContext(older_context)) {
new_plan_sp = m_thread.QueueThreadPlanForStepOutNoShouldStop(
false, nullptr, true, stop_others, eVoteNo, eVoteNoOpinion, 0,
m_status, true);
break;
} else {
new_plan_sp = m_thread.QueueThreadPlanForStepThrough(
m_stack_id, false, stop_others, m_status);
// If we found a way through, then we should stop recursing.
if (new_plan_sp)
break;
}
}
} else {
// If we're still in the range, keep going.
if (InRange()) {
SetNextBranchBreakpoint();
return false;
}
if (!InSymbol()) {
// This one is a little tricky. Sometimes we may be in a stub or
// something similar, in which case we need to get out of there. But if
// we are in a stub then it's likely going to be hard to get out from
// here. It is probably easiest to step into the stub, and then it will
// be straight-forward to step out.
new_plan_sp = m_thread.QueueThreadPlanForStepThrough(
m_stack_id, false, stop_others, m_status);
} else {
// The current clang (at least through 424) doesn't always get the
// address range for the DW_TAG_inlined_subroutines right, so that when
// you leave the inlined range the line table says you are still in the
// source file of the inlining function. This is bad, because now you
// are missing the stack frame for the function containing the inlining,
// and if you sensibly do "finish" to get out of this function you will
// instead exit the containing function. To work around this, we check
// whether we are still in the source file we started in, and if not
// assume it is an error, and push a plan to get us out of this line and
// back to the containing file.
if (m_addr_context.line_entry.IsValid()) {
SymbolContext sc;
StackFrameSP frame_sp = m_thread.GetStackFrameAtIndex(0);
sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
if (sc.line_entry.IsValid()) {
if (sc.line_entry.original_file !=
m_addr_context.line_entry.original_file &&
sc.comp_unit == m_addr_context.comp_unit &&
sc.function == m_addr_context.function) {
// Okay, find the next occurrence of this file in the line table:
LineTable *line_table = m_addr_context.comp_unit->GetLineTable();
if (line_table) {
Address cur_address = frame_sp->GetFrameCodeAddress();
uint32_t entry_idx;
LineEntry line_entry;
if (line_table->FindLineEntryByAddress(cur_address, line_entry,
&entry_idx)) {
LineEntry next_line_entry;
bool step_past_remaining_inline = false;
if (entry_idx > 0) {
// We require the previous line entry and the current line
// entry come from the same file. The other requirement is
// that the previous line table entry be part of an inlined
// block, we don't want to step past cases where people have
// inlined some code fragment by using #include <source-
// fragment.c> directly.
LineEntry prev_line_entry;
if (line_table->GetLineEntryAtIndex(entry_idx - 1,
prev_line_entry) &&
prev_line_entry.original_file ==
line_entry.original_file) {
SymbolContext prev_sc;
Address prev_address =
prev_line_entry.range.GetBaseAddress();
prev_address.CalculateSymbolContext(&prev_sc);
if (prev_sc.block) {
Block *inlined_block =
prev_sc.block->GetContainingInlinedBlock();
if (inlined_block) {
AddressRange inline_range;
inlined_block->GetRangeContainingAddress(prev_address,
inline_range);
if (!inline_range.ContainsFileAddress(cur_address)) {
step_past_remaining_inline = true;
}
}
}
}
}
if (step_past_remaining_inline) {
uint32_t look_ahead_step = 1;
while (line_table->GetLineEntryAtIndex(
entry_idx + look_ahead_step, next_line_entry)) {
// Make sure we haven't wandered out of the function we
// started from...
Address next_line_address =
next_line_entry.range.GetBaseAddress();
Function *next_line_function =
next_line_address.CalculateSymbolContextFunction();
if (next_line_function != m_addr_context.function)
break;
if (next_line_entry.original_file ==
m_addr_context.line_entry.original_file) {
const bool abort_other_plans = false;
const RunMode stop_other_threads = RunMode::eAllThreads;
lldb::addr_t cur_pc = m_thread.GetStackFrameAtIndex(0)
->GetRegisterContext()
->GetPC();
AddressRange step_range(
cur_pc,
next_line_address.GetLoadAddress(&GetTarget()) -
cur_pc);
new_plan_sp = m_thread.QueueThreadPlanForStepOverRange(
abort_other_plans, step_range, sc, stop_other_threads,
m_status);
break;
}
look_ahead_step++;
}
}
}
}
}
}
}
}
}
// If we get to this point, we're not going to use a previously set "next
// branch" breakpoint, so delete it:
ClearNextBranchBreakpoint();
// If we haven't figured out something to do yet, then ask the ShouldStopHere
// callback:
if (!new_plan_sp) {
new_plan_sp = CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
}
if (!new_plan_sp)
m_no_more_plans = true;
else {
// Any new plan will be an implementation plan, so mark it private:
new_plan_sp->SetPrivate(true);
m_no_more_plans = false;
}
if (!new_plan_sp) {
// For efficiencies sake, we know we're done here so we don't have to do
// this calculation again in MischiefManaged.
SetPlanComplete(m_status.Success());
return true;
} else
return false;
}
bool ThreadPlanStepOverRange::DoPlanExplainsStop(Event *event_ptr) {
// For crashes, breakpoint hits, signals, etc, let the base plan (or some
// plan above us) handle the stop. That way the user can see the stop, step
// around, and then when they are done, continue and have their step
// complete. The exception is if we've hit our "run to next branch"
// breakpoint. Note, unlike the step in range plan, we don't mark ourselves
// complete if we hit an unexplained breakpoint/crash.
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
StopInfoSP stop_info_sp = GetPrivateStopInfo();
bool return_value;
if (stop_info_sp) {
StopReason reason = stop_info_sp->GetStopReason();
if (reason == eStopReasonTrace) {
return_value = true;
} else if (reason == eStopReasonBreakpoint) {
return_value = NextRangeBreakpointExplainsStop(stop_info_sp);
} else {
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;
return return_value;
}
bool ThreadPlanStepOverRange::DoWillResume(lldb::StateType resume_state,
bool current_plan) {
if (resume_state != eStateSuspended && m_first_resume) {
m_first_resume = false;
if (resume_state == eStateStepping && current_plan) {
// See if we are about to step over an inlined call in the middle of the
// inlined stack, if so figure out its extents and reset our range to
// step over that.
bool in_inlined_stack = m_thread.DecrementCurrentInlinedDepth();
if (in_inlined_stack) {
Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
LLDB_LOGF(log,
"ThreadPlanStepInRange::DoWillResume: adjusting range to "
"the frame at inlined depth %d.",
m_thread.GetCurrentInlinedDepth());
StackFrameSP stack_sp = m_thread.GetStackFrameAtIndex(0);
if (stack_sp) {
Block *frame_block = stack_sp->GetFrameBlock();
lldb::addr_t curr_pc = m_thread.GetRegisterContext()->GetPC();
AddressRange my_range;
if (frame_block->GetRangeContainingLoadAddress(
curr_pc, m_thread.GetProcess()->GetTarget(), my_range)) {
m_address_ranges.clear();
m_address_ranges.push_back(my_range);
if (log) {
StreamString s;
const InlineFunctionInfo *inline_info =
frame_block->GetInlinedFunctionInfo();
const char *name;
if (inline_info)
name =
inline_info
->GetName(frame_block->CalculateSymbolContextFunction()
->GetLanguage())
.AsCString();
else
name = "<unknown-notinlined>";
s.Printf(
"Stepping over inlined function \"%s\" in inlined stack: ",
name);
DumpRanges(&s);
log->PutString(s.GetString());
}
}
}
}
}
}
return true;
}