Commit 20ce8aff authored by Fred Riss's avatar Fred Riss
Browse files

[lldb/API] NFC: Reformat and simplify SBThread::GetStopDescription() 

Summary:
This gets rid of some nesting and of the raw char* variable that caused
the memory management bug we hit recently.

This commit also removes the fallback code which should trigger when
the StopInfo provides no stop description. All currently implemented
StopInfos have a `GetDescription()` method that shouldn't return an
empty description.

Reviewers: JDevlieghere, labath, mib

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74157
parent c0a2da94

lldb/source/API/SBThread.cpp

+15 −87
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include "lldb/Target/ThreadPlanStepInstruction.h"

#include "lldb/Target/ThreadPlanStepOut.h"

#include "lldb/Target/ThreadPlanStepRange.h"

#include "lldb/Target/UnixSignals.h"

#include "lldb/Utility/State.h"

#include "lldb/Utility/Stream.h"

#include "lldb/Utility/StructuredData.h"
@@ -319,97 +318,26 @@ size_t SBThread::GetStopDescription(char *dst, size_t dst_len) { 
  std::unique_lock<std::recursive_mutex> lock;

  ExecutionContext exe_ctx(m_opaque_sp.get(), lock);



  if (exe_ctx.HasThreadScope()) {

    Process::StopLocker stop_locker;

    if (stop_locker.TryLock(&exe_ctx.GetProcessPtr()->GetRunLock())) {



      StopInfoSP stop_info_sp = exe_ctx.GetThreadPtr()->GetStopInfo();

      if (stop_info_sp) {

        std::string thread_stop_desc =

            exe_ctx.GetThreadPtr()->GetStopDescription();

        const char *stop_desc = thread_stop_desc.c_str();



        if (stop_desc[0] != '\0') {

  if (dst)

            return ::snprintf(dst, dst_len, "%s", stop_desc);

          else {

            // NULL dst passed in, return the length needed to contain the

            // description

            return ::strlen(stop_desc) + 1; // Include the NULL byte for size

          }

        } else {

          size_t stop_desc_len = 0;

          switch (stop_info_sp->GetStopReason()) {

          case eStopReasonTrace:

          case eStopReasonPlanComplete: {

            static char trace_desc[] = "step";

            stop_desc = trace_desc;

            stop_desc_len =

                sizeof(trace_desc); // Include the NULL byte for size

          } break;



          case eStopReasonBreakpoint: {

            static char bp_desc[] = "breakpoint hit";

            stop_desc = bp_desc;

            stop_desc_len = sizeof(bp_desc); // Include the NULL byte for size

          } break;



          case eStopReasonWatchpoint: {

            static char wp_desc[] = "watchpoint hit";

            stop_desc = wp_desc;

            stop_desc_len = sizeof(wp_desc); // Include the NULL byte for size

          } break;



          case eStopReasonSignal: {

            stop_desc =

                exe_ctx.GetProcessPtr()->GetUnixSignals()->GetSignalAsCString(

                    stop_info_sp->GetValue());

            if (stop_desc == nullptr || stop_desc[0] == '\0') {

              static char signal_desc[] = "signal";

              stop_desc = signal_desc;

              stop_desc_len =

                  sizeof(signal_desc); // Include the NULL byte for size

            }

          } break;

    *dst = 0;



          case eStopReasonException: {

            char exc_desc[] = "exception";

            stop_desc = exc_desc;

            stop_desc_len = sizeof(exc_desc); // Include the NULL byte for size

          } break;

  if (!exe_ctx.HasThreadScope())

    return 0;



          case eStopReasonExec: {

            char exc_desc[] = "exec";

            stop_desc = exc_desc;

            stop_desc_len = sizeof(exc_desc); // Include the NULL byte for size

          } break;

  Process::StopLocker stop_locker;

  if (!stop_locker.TryLock(&exe_ctx.GetProcessPtr()->GetRunLock()))

    return 0;



          case eStopReasonThreadExiting: {

            char limbo_desc[] = "thread exiting";

            stop_desc = limbo_desc;

            stop_desc_len = sizeof(limbo_desc);

          } break;

          default:

            break;

          }

  std::string thread_stop_desc = exe_ctx.GetThreadPtr()->GetStopDescription();

  if (thread_stop_desc.empty())

    return 0;



          if (stop_desc && stop_desc[0]) {

  if (dst)

              return ::snprintf(dst, dst_len, "%s", stop_desc) +

                     1; // Include the NULL byte

    return ::snprintf(dst, dst_len, "%s", thread_stop_desc.c_str()) + 1;



            if (stop_desc_len == 0)

              stop_desc_len = ::strlen(stop_desc) + 1; // Include the NULL byte



            return stop_desc_len;

          }

        }

      }

    }

  }

  if (dst)

    *dst = 0;

  return 0;

  // NULL dst passed in, return the length needed to contain the

  // description.

  return thread_stop_desc.size() + 1; // Include the NULL byte for size

}



SBValue SBThread::GetStopReturnValue() {

lldb/source/Target/Thread.cpp

+5 −1
Original line number Diff line number Diff line
@@ -596,8 +596,12 @@ std::string Thread::GetStopDescription() { 
std::string Thread::GetStopDescriptionRaw() {

  StopInfoSP stop_info_sp = GetStopInfo();

  std::string raw_stop_description;

  if (stop_info_sp && stop_info_sp->IsValid())

  if (stop_info_sp && stop_info_sp->IsValid()) {

    raw_stop_description = stop_info_sp->GetDescription();

    assert((!raw_stop_description.empty() ||

            stop_info_sp->GetStopReason() == eStopReasonNone) &&

           "StopInfo returned an empty description.");

  }

  return raw_stop_description;

}