3 files changed, 30 insertions, 6 deletions
diff --git a/lldb/source/Core/Disassembler.cpp b/lldb/source/Core/Disassembler.cpp
index 89ae25cbad6..33172cc8868 100644
--- a/lldb/source/Core/Disassembler.cpp
+++ b/lldb/source/Core/Disassembler.cpp
@@ -1101,15 +1101,22 @@ void InstructionList::Append(lldb::InstructionSP &inst_sp) {
 uint32_t
 InstructionList::GetIndexOfNextBranchInstruction(uint32_t start,
                                                  Target &target,
-                                                 bool ignore_calls) const {
+                                                 bool ignore_calls,
+                                                 bool *found_calls) const {
   size_t num_instructions = m_instructions.size();
 
   uint32_t next_branch = UINT32_MAX;
   size_t i;
+  
+  if (found_calls)
+    *found_calls = false;
   for (i = start; i < num_instructions; i++) {
     if (m_instructions[i]->DoesBranch()) {
-      if (ignore_calls && m_instructions[i]->IsCall())
+      if (ignore_calls && m_instructions[i]->IsCall()) {
+        if (found_calls)
+          *found_calls = true;
         continue;
+      }
       next_branch = i;
       break;
     }
diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index a731a353c1b..a8fb32dafa8 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -5800,7 +5800,8 @@ Process::AdvanceAddressToNextBranchInstruction(Address default_stop_addr,
 
   uint32_t branch_index =
       insn_list->GetIndexOfNextBranchInstruction(insn_offset, target,
-                                                 false /* ignore_calls*/);
+                                                 false /* ignore_calls*/,
+                                                 nullptr);
   if (branch_index == UINT32_MAX) {
     return retval;
   }
diff --git a/lldb/source/Target/ThreadPlanStepRange.cpp b/lldb/source/Target/ThreadPlanStepRange.cpp
index 27513a34ead..a22337deaed 100644
--- a/lldb/source/Target/ThreadPlanStepRange.cpp
+++ b/lldb/source/Target/ThreadPlanStepRange.cpp
@@ -238,8 +238,18 @@ lldb::FrameComparison ThreadPlanStepRange::CompareCurrentFrameToStartFrame() {
 }
 
 bool ThreadPlanStepRange::StopOthers() {
-  return (m_stop_others == lldb::eOnlyThisThread ||
-          m_stop_others == lldb::eOnlyDuringStepping);
+  switch (m_stop_others) {
+  case lldb::eOnlyThisThread:
+    return true;
+  case lldb::eOnlyDuringStepping:
+    // If there is a call in the range of the next branch breakpoint,
+    // then we should always run all threads, since a call can execute
+    // arbitrary code which might for instance take a lock that's held
+    // by another thread.
+    return !m_found_calls;
+  case lldb::eAllThreads:
+    return false;
+  }
 }
 
 InstructionList *ThreadPlanStepRange::GetInstructionsForAddress(
@@ -292,6 +302,7 @@ void ThreadPlanStepRange::ClearNextBranchBreakpoint() {
     GetTarget().RemoveBreakpointByID(m_next_branch_bp_sp->GetID());
     m_next_branch_bp_sp.reset();
     m_could_not_resolve_hw_bp = false;
+    m_found_calls = false;
   }
 }
 
@@ -305,6 +316,9 @@ bool ThreadPlanStepRange::SetNextBranchBreakpoint() {
   if (!m_use_fast_step)
     return false;
 
+  // clear the m_found_calls, we'll rediscover it for this range.
+  m_found_calls = false;
+  
   lldb::addr_t cur_addr = GetThread().GetRegisterContext()->GetPC();
   // Find the current address in our address ranges, and fetch the disassembly
   // if we haven't already:
@@ -317,9 +331,11 @@ bool ThreadPlanStepRange::SetNextBranchBreakpoint() {
   else {
     Target &target = GetThread().GetProcess()->GetTarget();
     const bool ignore_calls = GetKind() == eKindStepOverRange;
+    bool found_calls;
     uint32_t branch_index =
         instructions->GetIndexOfNextBranchInstruction(pc_index, target,
-                                                      ignore_calls);
+                                                      ignore_calls, 
+                                                      &m_found_calls);
 
     Address run_to_address;