<rdar://problem/14134716>

This is a rewrite of the command history facility of LLDB

It takes the history management out of the CommandInterpreter into its own CommandHistory class
It reimplements the command history command to allow more combinations of options to work correctly (e.g. com hist -c 1 -s 5)
It adds a new --wipe (-w) option to command history to allow clearing the history on demand
It extends the lldbtest runCmd: and expect: methods to allow adding commands to history if need be
It adds a test case for the reimplemented facility



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@184140 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Utility/Range.cpp b/source/Utility/Range.cpp
new file mode 100644
index 0000000..158d1e7
--- /dev/null
+++ b/source/Utility/Range.cpp
@@ -0,0 +1,103 @@
+//===--------------------- Range.cpp -----------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/Range.h"
+
+using namespace lldb_utility;
+
+Range::Range (const Range& rng) :
+m_low(rng.m_low),
+m_high(rng.m_high)
+{
+    InitRange();
+}
+
+Range::Range (Range::ValueType low,
+              Range::ValueType high) :
+m_low(low),
+m_high(high)
+{
+    InitRange();
+}
+
+void
+Range::InitRange ()
+{
+    if (m_low == OPEN_END)
+    {
+        if (m_high == OPEN_END)
+            m_low = 0;
+        else
+        {
+            // make an empty range
+            m_low = 1;
+            m_high = 0;
+        }
+    }
+}
+
+Range&
+Range::operator = (const Range& rhs)
+{
+    if (&rhs != this)
+    {
+        this->m_low = rhs.m_low;
+        this->m_high = rhs.m_high;
+    }
+    return *this;
+}
+
+void
+Range::Flip ()
+{
+    std::swap(m_high, m_low);
+}
+
+void
+Range::Intersection (const Range& other)
+{
+    m_low = std::max(m_low,other.m_low);
+    m_high = std::min(m_high,other.m_high);
+}
+
+void
+Range::Union (const Range& other)
+{
+    m_low = std::min(m_low,other.m_low);
+    m_high = std::max(m_high,other.m_high);
+}
+
+void
+Range::Iterate (RangeCallback callback)
+{
+    ValueType counter = m_low;
+    while (counter <= m_high)
+    {
+        bool should_continue = callback(counter);
+        if (!should_continue)
+            return;
+        counter++;
+    }
+}
+
+bool
+Range::IsEmpty ()
+{
+    return (m_low > m_high);
+}
+
+Range::ValueType
+Range::GetSize ()
+{
+    if (m_high == OPEN_END)
+        return OPEN_END;
+    if (m_high >= m_low)
+        return m_high - m_low + 1;
+    return 0;
+}