Initial merge of some of the iOS 8 / Mac OS X Yosemite specific
lldb support.  I'll be doing more testing & cleanup but I wanted to
get the initial checkin done.

This adds a new SBExpressionOptions::SetLanguage API for selecting a
language of an expression.

I added adds a new SBThread::GetInfoItemByPathString for retriving
information about a thread from that thread's StructuredData.

I added a new StructuredData class for representing
key-value/array/dictionary information (e.g. JSON formatted data).
Helper functions to read JSON and create a StructuredData object,
and to print a StructuredData object in JSON format are included.

A few Cocoa / Cocoa Touch data formatters were updated by Enrico
to track changes in iOS 8 / Yosemite.

Before we query a thread's extended information, the system runtime may 
provide hints to the remote debug stub that it will use to retrieve values
out of runtime structures.  I added a new SystemRuntime method 
AddThreadExtendedInfoPacketHints which allows the SystemRuntime to add 
key-value type data to the initial request that we send to the remote stub.

The thread-format formatter string can now retrieve values out of a thread's
extended info structured data.  The default thread-format string picks up
two of these - thread.info.activity.name and thread.info.trace_messages.

I added a new "jThreadExtendedInfo" packet in debugserver; I will
add documentation to the lldb-gdb-remote.txt doc soon.  It accepts
JSON formatted arguments (most importantly, "thread":threadnum) and
it returns a variety of information regarding the thread to lldb
in JSON format.  This JSON return is scanned into a StructuredData
object that is associated with the thread; UI layers can query the
thread's StructuredData to see if key-values are present, and if
so, show them to the user.  These key-values are likely to be
specific to different targets with some commonality among many
targets.  For instance, many targets will be able to advertise the
pthread_t value for a thread.

I added an initial rough cut of "thread info" command which will print
the information about a thread from the jThreadExtendedInfo result.
I need to do more work to make this format reasonably.

Han Ming added calls into the pmenergy and pmsample libraries if
debugserver is run on Mac OS X Yosemite to get information about the
inferior's power use.

I added support to debugserver for gathering the Genealogy information
about threads, if it exists, and returning it in the jThreadExtendedInfo
JSON result.

llvm-svn: 210874
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index b79a697..7adf916 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -56,6 +56,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/TargetList.h"
 #include "lldb/Target/ThreadPlanCallFunction.h"
+#include "lldb/Target/SystemRuntime.h"
 #include "lldb/Utility/PseudoTerminal.h"
 
 // Project includes
@@ -3149,6 +3150,50 @@
     return buf;
 }
 
+StructuredData::ObjectSP
+ProcessGDBRemote::GetExtendedInfoForThread (lldb::tid_t tid)
+{
+    StructuredData::ObjectSP object_sp;
+
+    if (m_gdb_comm.GetThreadExtendedInfoSupported())
+    {
+        StructuredData::ObjectSP args_dict(new StructuredData::Dictionary());
+        SystemRuntime *runtime = GetSystemRuntime();
+        if (runtime)
+        {
+            runtime->AddThreadExtendedInfoPacketHints (args_dict);
+        }
+        args_dict->GetAsDictionary()->AddIntegerItem ("thread", tid);
+
+        StreamString packet;
+        packet << "jThreadExtendedInfo:";
+        args_dict->Dump (packet);
+
+        // FIXME the final character of a JSON dictionary, '}', is the escape
+        // character in gdb-remote binary mode.  lldb currently doesn't escape
+        // these characters in its packet output -- so we add the quoted version
+        // of the } character here manually in case we talk to a debugserver which
+        // un-escapes the chracters at packet read time.
+        packet << (char) (0x7d ^ 0x20);
+
+        StringExtractorGDBRemote response;
+        if (m_gdb_comm.SendPacketAndWaitForResponse(packet.GetData(), packet.GetSize(), response, false) == GDBRemoteCommunication::PacketResult::Success)
+        {
+            StringExtractorGDBRemote::ResponseType response_type = response.GetResponseType();
+            if (response_type == StringExtractorGDBRemote::eResponse)
+            {
+                if (!response.Empty())
+                {
+                    // The packet has already had the 0x7d xor quoting stripped out at the
+                    // GDBRemoteCommunication packet receive level.
+                    object_sp = StructuredData::ParseJSON (response.GetStringRef());
+                }
+            }
+        }
+    }
+    return object_sp;
+}
+
 // Establish the largest memory read/write payloads we should use.
 // If the remote stub has a max packet size, stay under that size.
 //