From 17d023f6ac0326706aa7726895550c015befb451 Mon Sep 17 00:00:00 2001
From: Jim Ingham <jingham@apple.com>
Date: Wed, 13 Mar 2013 17:58:04 +0000
Subject: [PATCH] Add a target setting (target.use-fast-stepping) to control
 using the "run to next branch" stepping algorithm.

llvm-svn: 176958
---
 lldb/include/lldb/Target/Target.h          |  5 ++++-
 lldb/source/Target/Target.cpp              | 11 ++++++++++-
 lldb/source/Target/ThreadPlanStepRange.cpp |  1 +
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/lldb/include/lldb/Target/Target.h b/lldb/include/lldb/Target/Target.h
index 282a8fa3fde8..928b7e3ab072 100644
--- a/lldb/include/lldb/Target/Target.h
+++ b/lldb/include/lldb/Target/Target.h
@@ -144,7 +144,10 @@ public:
     
     const char *
     GetExpressionPrefixContentsAsCString ();
-
+    
+    bool
+    GetUseFastStepping() const;
+    
 };
 
 typedef STD_SHARED_PTR(TargetProperties) TargetPropertiesSP;
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index 1cc48dcc665a..9e9aa563f7d4 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -2261,6 +2261,7 @@ g_properties[] =
         "file and line breakpoints." },
     // FIXME: This is the wrong way to do per-architecture settings, but we don't have a general per architecture settings system in place yet.
     { "x86-disassembly-flavor"             , OptionValue::eTypeEnum      , false, eX86DisFlavorDefault,       NULL, g_x86_dis_flavor_value_types, "The default disassembly flavor to use for x86 or x86-64 targets." },
+    { "use-fast-stepping"                  , OptionValue::eTypeBoolean   , false, false,                      NULL, NULL, "Use a fast stepping algorithm based on running from branch to branch rather than instruction single-stepping." },
     { NULL                                 , OptionValue::eTypeInvalid   , false, 0                         , NULL, NULL, NULL }
 };
 enum
@@ -2285,7 +2286,8 @@ enum
     ePropertyDisableASLR,
     ePropertyDisableSTDIO,
     ePropertyInlineStrategy,
-    ePropertyDisassemblyFlavor
+    ePropertyDisassemblyFlavor,
+    ePropertyUseFastStepping
 };
 
 
@@ -2624,6 +2626,13 @@ TargetProperties::GetBreakpointsConsultPlatformAvoidList ()
     return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
 }
 
+bool
+TargetProperties::GetUseFastStepping () const
+{
+    const uint32_t idx = ePropertyUseFastStepping;
+    return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
+}
+
 const TargetPropertiesSP &
 Target::GetGlobalProperties()
 {
diff --git a/lldb/source/Target/ThreadPlanStepRange.cpp b/lldb/source/Target/ThreadPlanStepRange.cpp
index 52048064d2c5..7f93f3fe8f9a 100644
--- a/lldb/source/Target/ThreadPlanStepRange.cpp
+++ b/lldb/source/Target/ThreadPlanStepRange.cpp
@@ -54,6 +54,7 @@ ThreadPlanStepRange::ThreadPlanStepRange (ThreadPlanKind kind,
     m_first_run_event (true),
     m_use_fast_step(false)
 {
+    m_use_fast_step = GetTarget().GetUseFastStepping();
     AddRange(range);
     m_stack_id = m_thread.GetStackFrameAtIndex(0)->GetStackID();
 }