Add setting to require hardware breakpoints.
When debugging read-only memory we cannot use software breakpoint. We
already have support for hardware breakpoints and users can specify them
with `-H`. However, there's no option to force LLDB to use hardware
breakpoints internally, for example while stepping.
This patch adds a setting target.require-hardware-breakpoint that forces
LLDB to always use hardware breakpoints. Because hardware breakpoints
are a limited resource and can fail to resolve, this patch also extends
error handling in thread plans, where breakpoints are used for stepping.
Differential revision: https://reviews.llvm.org/D54221
llvm-svn: 346920
diff --git a/lldb/source/Target/ThreadPlanStepInRange.cpp b/lldb/source/Target/ThreadPlanStepInRange.cpp
index 6784e89..8f9889a 100644
--- a/lldb/source/Target/ThreadPlanStepInRange.cpp
+++ b/lldb/source/Target/ThreadPlanStepInRange.cpp
@@ -108,8 +108,16 @@
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;
}
@@ -130,6 +138,8 @@
DumpRanges(s);
}
+ PrintFailureIfAny();
+
s->PutChar('.');
}
@@ -162,7 +172,8 @@
// 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_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
@@ -181,11 +192,12 @@
// 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 = m_thread.QueueThreadPlanForStepThrough(m_stack_id, false,
- stop_others);
+ m_sub_plan_sp = m_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_sub_plan_sp =
+ CheckShouldStopHereAndQueueStepOut(frame_order, m_status);
if (log) {
if (m_sub_plan_sp)
log->Printf("ShouldStopHere found plan to step out of this frame.");
@@ -223,8 +235,8 @@
// We may have set the plan up above in the FrameIsOlder section:
if (!m_sub_plan_sp)
- m_sub_plan_sp = m_thread.QueueThreadPlanForStepThrough(m_stack_id, false,
- stop_others);
+ m_sub_plan_sp = m_thread.QueueThreadPlanForStepThrough(
+ m_stack_id, false, stop_others, m_status);
if (log) {
if (m_sub_plan_sp)
@@ -236,7 +248,7 @@
// 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_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.
@@ -284,7 +296,7 @@
log->Printf("Pushing past prologue ");
m_sub_plan_sp = m_thread.QueueThreadPlanForRunToAddress(
- false, func_start_address, true);
+ false, func_start_address, true, m_status);
}
}
}
@@ -380,7 +392,7 @@
bool ThreadPlanStepInRange::DefaultShouldStopHereCallback(
ThreadPlan *current_plan, Flags &flags, FrameComparison operation,
- void *baton) {
+ 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));
@@ -388,7 +400,7 @@
// First see if the ThreadPlanShouldStopHere default implementation thinks we
// should get out of here:
should_stop_here = ThreadPlanShouldStopHere::DefaultShouldStopHereCallback(
- current_plan, flags, operation, baton);
+ current_plan, flags, operation, status, baton);
if (!should_stop_here)
return should_stop_here;