Fix unused variable, format, and format string warnings.
NFC.
diff --git a/lldb/include/lldb/Target/ThreadPlanStack.h b/lldb/include/lldb/Target/ThreadPlanStack.h
index de52ee3..f187413 100644
--- a/lldb/include/lldb/Target/ThreadPlanStack.h
+++ b/lldb/include/lldb/Target/ThreadPlanStack.h
@@ -125,7 +125,7 @@
 
   void AddThread(Thread &thread) {
     lldb::tid_t tid = thread.GetID();
-    auto result = m_plans_list.emplace(tid, thread);
+    m_plans_list.emplace(tid, thread);
   }
 
   bool RemoveTID(lldb::tid_t tid) {
diff --git a/lldb/source/Commands/CommandObjectThread.cpp b/lldb/source/Commands/CommandObjectThread.cpp
index 579f336..fe86c9d 100644
--- a/lldb/source/Commands/CommandObjectThread.cpp
+++ b/lldb/source/Commands/CommandObjectThread.cpp
@@ -2061,7 +2061,6 @@
       return true;  
     }
 
-    bool success;
     const size_t num_args = args.GetArgumentCount();
 
     std::lock_guard<std::recursive_mutex> guard(
diff --git a/lldb/source/Target/ThreadPlan.cpp b/lldb/source/Target/ThreadPlan.cpp
index 52b1a8b..b3ff323 100644
--- a/lldb/source/Target/ThreadPlan.cpp
+++ b/lldb/source/Target/ThreadPlan.cpp
@@ -24,7 +24,7 @@
     : m_process(*thread.GetProcess().get()), m_tid(thread.GetID()),
       m_stop_vote(stop_vote), m_run_vote(run_vote),
       m_takes_iteration_count(false), m_could_not_resolve_hw_bp(false),
-      m_kind(kind), m_thread(&thread), m_name(name), m_plan_complete_mutex(),
+      m_thread(&thread), m_kind(kind), m_name(name), m_plan_complete_mutex(),
       m_cached_plan_explains_stop(eLazyBoolCalculate), m_plan_complete(false),
       m_plan_private(false), m_okay_to_discard(true), m_is_master_plan(false),
       m_plan_succeeded(true) {
diff --git a/lldb/source/Target/ThreadPlanStack.cpp b/lldb/source/Target/ThreadPlanStack.cpp
index 6120d0c..44e47f3 100644
--- a/lldb/source/Target/ThreadPlanStack.cpp
+++ b/lldb/source/Target/ThreadPlanStack.cpp
@@ -39,9 +39,6 @@
 void ThreadPlanStack::DumpThreadPlans(Stream &s,
                                       lldb::DescriptionLevel desc_level,
                                       bool include_internal) const {
-
-  uint32_t stack_size;
-
   s.IndentMore();
   PrintOneStack(s, "Active plan stack", m_plans, desc_level, include_internal);
   PrintOneStack(s, "Completed plan stack", m_completed_plans, desc_level,
@@ -73,7 +70,7 @@
   if (include_internal || any_public) {
     int print_idx = 0;
     s.Indent();
-    s.Printf("%s:\n", stack_name);
+    s << stack_name << ":\n";
     for (auto plan : stack) {
       if (!include_internal && plan->GetPrivate())
         continue;
@@ -270,7 +267,6 @@
 lldb::ThreadPlanSP ThreadPlanStack::GetPlanByIndex(uint32_t plan_idx,
                                                    bool skip_private) const {
   uint32_t idx = 0;
-  ThreadPlan *up_to_plan_ptr = nullptr;
 
   for (lldb::ThreadPlanSP plan_sp : m_plans) {
     if (skip_private && plan_sp->GetPrivate())
diff --git a/lldb/source/Target/ThreadPlanStepRange.cpp b/lldb/source/Target/ThreadPlanStepRange.cpp
index 85b89e7..f4b2ee3 100644
--- a/lldb/source/Target/ThreadPlanStepRange.cpp
+++ b/lldb/source/Target/ThreadPlanStepRange.cpp
@@ -86,7 +86,6 @@
 }
 
 void ThreadPlanStepRange::DumpRanges(Stream *s) {
-  Thread &thread = GetThread();
   size_t num_ranges = m_address_ranges.size();
   if (num_ranges == 1) {
     m_address_ranges[0].Dump(s, &GetTarget(), Address::DumpStyleLoadAddress);