Hi Pavel,
This is the code:
int main() {
using namespace lldb;
SBDebugger::Initialize();
SBDebugger debugger = SBDebugger::Create(true);
if(!debugger.IsValid()) {
return 1;
}
SBTarget target = debugger.CreateTarget("/home/cynecx/dev/helloWorld/main");
if(!target.IsValid()) {
return 1;
}
SBBreakpoint bp1 = target.BreakpointCreateByLocation(
"/home/cynecx/dev/helloWorld/main.cpp", 7);
if(!bp1.IsValid()) {
return 1;
}
bp1.SetEnabled(true);
const char* args[] = { "/home/cynecx/dev/helloWorld/main", 0 };
const char* env[] = { 0 };
SBLaunchInfo launch_info(args);
launch_info.SetEnvironmentEntries(env, true);
launch_info.SetWorkingDirectory("/home/cynecx/dev/helloWorld");
launch_info.SetLaunchFlags(eLaunchFlagStopAtEntry);
SBError error;
SBProcess process = target.Launch(launch_info, error);
if(!process.IsValid() || !error.Success()) {
return 1;
}
error = process.Continue();
if(!error.Success()) {
return 1;
}
while(true) {
SBEvent event;
SBListener listener = debugger.GetListener();
if(listener.WaitForEvent(6, event)) {
if(!event.IsValid()) {
break;
}
const uint32_t event_type = event.GetType();
if (!SBProcess::EventIsProcessEvent(event)) {
continue;
}
if(event_type == SBProcess::eBroadcastBitStateChanged) {
const StateType state = SBProcess::GetStateFromEvent(event);
switch(state) {
default:
continue;
case eStateStopped: {
// static bool runOnce = false;
//
// if(runOnce == false) {
// sleep(1);
// runOnce = true;
// }
SBThread thread = process.GetThreadAtIndex(0);
SBStream stream;
thread.GetStatus(stream);
event.GetDescription(stream);
std::cout << stream.GetData() << std::endl;
auto threadStopReason = thread.GetStopReason();
if(threadStopReason == eStopReasonBreakpoint) {
uint64_t bpId = thread.GetStopReasonDataAtIndex(0);
if(bpId == static_cast<uint64_t>(bp1.GetID())) {
std::cout << "Stopped at breakpoint" << std::endl;
thread.StepOver();
}
} else if (threadStopReason == eStopReasonPlanComplete) {
std::cout << "Stopped at step" << std::endl;
}
break;
}
}
} else if (SBProcess::eBroadcastBitSTDOUT) {
char buffer[1024];
size_t num_bytes = 0;
do
{
num_bytes = process.GetSTDOUT(buffer, sizeof(buffer));
if (num_bytes > 0)
printf("%*s", (int)num_bytes, buffer);
} while (num_bytes == sizeof(buffer));
}
std::cout << "----------" << std::endl;
} else {
break;
}
}
SBDebugger::Terminate();
return 0;
}
main.cpp:
#include <cstddef>
#include <cstdint>
#include <iostream>
int main() {
std::cout << "Hello World" << std::endl;
int i = 0;
std::cin >> i;
if (i == 1) {
return 1;
}
return 0;
}
So the problem is that I am not getting correct thread information
when receiving an eStateStopped event. It kinda seems that when
"thread.GetStatus(stream);", the thread hasn't stopped yet so I always
getting non-determine thread information.
I found out that on my linux vm, it works properly so I thought it
might be an issue with the kernel and stuff but I kinda found a
workaround by simply putting a sleep(1) before querying the thread
information. As expected it gave me correct thread information, also
the step-over worked properly because the thread plan used correct
line information.
To compare both outputs:
Correct one (with sleep(1)):
* thread #1: tid = 5862, 0x0000000000400953 main`main + 35 at
main.cpp:7, name = 'main', stop reason = breakpoint 1.1
frame #0: 0x0000000000400953 main`main + 35 at main.cpp:7
4
5 int main() {
6
-> 7 std::cout << "Hello World" << std::endl;
8
9 int i = 0;
10 std::cin >> i;
0x7f1dc4000930 Event: broadcaster = 0x55da93268068 (lldb.process),
type = 0x00000001 (state-changed), data = { process = 0x55da93268030
(pid = 5862), state = stopped}
----------
* thread #1: tid = 5862, 0x0000000000400953 main`main + 35 at
main.cpp:7, name = 'main', stop reason = breakpoint 1.1
frame #0: 0x0000000000400953 main`main + 35 at main.cpp:7
4
5 int main() {
6
-> 7 std::cout << "Hello World" << std::endl;
8
9 int i = 0;
10 std::cin >> i;
0x7f1dc4001640 Event: broadcaster = 0x55da93268068 (lldb.process),
type = 0x00000001 (state-changed), data = { process = 0x55da93268030
(pid = 5862), state = stopped}
Stopped at breakpoint
----------
Hello World
----------
* thread #1: tid = 5862, 0x0000000000400978 main`main + 72 at
main.cpp:9, name = 'main', stop reason = step over
frame #0: 0x0000000000400978 main`main + 72 at main.cpp:9
6
7 std::cout << "Hello World" << std::endl;
8
-> 9 int i = 0;
10 std::cin >> i;
11
12 if (i == 1) {
0x7f1dc4003ae0 Event: broadcaster = 0x55da93268068 (lldb.process),
type = 0x00000001 (state-changed), data = { process = 0x55da93268030
(pid = 5862), state = stopped}
Stopped at step
----------
And the one with non-determinism:
* thread #1: tid = 9097, 0x0000000000400830 main`_start, name = 'main'
frame #0: 0x0000000000400830 main`_start
main`_start:
0x400830 <+0>: xorl %ebp, %ebp
0x400832 <+2>: movq %rdx, %r9
0x400835 <+5>: popq %rsi
0x400836 <+6>: movq %rsp, %rdx
0x7fbdd0000930 Event: broadcaster = 0x564549feffa8 (lldb.process),
type = 0x00000001 (state-changed), data = { process = 0x564549feff70
(pid = 9097), state = stopped}
----------
* thread #1: tid = 9097, 0x0000000000400830 main`_start, name =
'main', stop reason = breakpoint 1.1
frame #0: 0x0000000000400830 main`_start
main`_start:
0x400830 <+0>: xorl %ebp, %ebp
0x400832 <+2>: movq %rdx, %r9
0x400835 <+5>: popq %rsi
0x400836 <+6>: movq %rsp, %rdx
0x7fbdd0001640 Event: broadcaster = 0x564549feffa8 (lldb.process),
type = 0x00000001 (state-changed), data = { process = 0x564549feff70
(pid = 9097), state = stopped}
Stopped at breakpoint
----------
Hello World
----------
2016-03-03 14:57 GMT+01:00 Pavel Labath <lab...@google.com>:
> Hi Paul,
>
> I haven't followed this discussion from the start, and I am now having
> trouble understanding what is the issue at hand here. Could you just
> briefly repeat what is the problem, and maybe send the code for
> reproducing the problem again? Maybe I'll be able to help...
>
> pl
>
> On 3 March 2016 at 13:04, Paul Peet via lldb-dev
> <lldb-dev@lists.llvm.org> wrote:
>> Sorry to bring this up again, but I am not sure if this is really a
>> linux kernel issue anymore, see the following code:
>>
>> if(event_type == SBProcess::eBroadcastBitStateChanged) {
>> const StateType state = SBProcess::GetStateFromEvent(event);
>>
>> switch(state) {
>> default:
>> continue;
>> case eStateStopped: {
>> static bool runOnce = false;
>> if(runOnce == false) {
>> sleep(1); // sleep a second
>> runOnce = true;
>> }
>>
>> SBThread thread = process.GetThreadAtIndex(0);
>> SBStream stream;
>>
>> As I said before that strangely it worked on the vm with kernel 4.4 so
>> I tried using kernel 4.4 and it still didn't work.
>>
>> Next thing I did was enabling lldb's logging and what I noticed was
>> that when the first thread plan is being made it had wrong instruction
>> information that's probably because the thread was still running. So
>> what I tried was this runOnce with a sleep(1) and the result was as I
>> expected, the thread plan contained the correct instruction
>> information and the following breakpoints and step-overs were
>> correctly made.
>>
>> Any chance that this issue lies deep in lldb? Would the lldb log help
>> to trace back the issue?
>>
>> 2016-02-29 19:58 GMT+01:00 Greg Clayton <gclay...@apple.com>:
>>>
>>>> On Feb 28, 2016, at 2:17 PM, Paul Peet <paulpee...@gmail.com> wrote:
>>>>
>>>> Hey,
>>>>
>>>> Just to let you know that I think I made some progress in determine the
>>>> problem.
>>>> I've basically setup an vm (archlinux, linux 4.4, lldb 3.7.1) and
>>>> tried the code on it. To my surprise it gave me proper output without
>>>> non-determinism. YEY.
>>>> I still don't have any idea why it's not working on my host system. I
>>>> might try testing linux 4.4 like I did on the vm.
>>>>
>>>> Do you have any idea/suspicion why it might not work on my system. (I
>>>> can provide additional information if needed).
>>>
>>> I don't. Maybe some of the linux experts out there might be able to help
>>> you. Are are working with top of tree LLDB sources right? You might post
>>> the exact linux setup you have in case that might allow people to help you
>>> out...
>>>
>>> Greg
>>>
>>>
>> _______________________________________________
>> lldb-dev mailing list
>> lldb-dev@lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
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