Index: lldb/trunk/test/tools/lldb-mi/TestMiGdbSetShow.py
===================================================================
--- lldb/trunk/test/tools/lldb-mi/TestMiGdbSetShow.py
+++ lldb/trunk/test/tools/lldb-mi/TestMiGdbSetShow.py
@@ -117,5 +117,53 @@
         self.runCmd("-gdb-show unknown")
         self.expect("\^error")
 
+
+    @lldbmi_test
+    @expectedFailureWindows("llvm.org/pr22274: need a pexpect replacement for windows")
+    @skipIfFreeBSD # llvm.org/pr22411: Failure presumably due to known thread races
+    @skipIfLinux # llvm.org/pr22841: lldb-mi tests fail on all Linux buildbots
+    def test_lldbmi_gdb_set_ouptut_radix(self):
+        """Test that 'lldb-mi --interpreter' works for -gdb-set output-radix."""
+
+        self.spawnLldbMi(args = None)
+
+        # Load executable
+        self.runCmd("-file-exec-and-symbols %s" % self.myexe)
+        self.expect("\^done")
+
+        # Run to BP_printf
+        line = line_number('main.cpp', '// BP_printf')
+        self.runCmd("-break-insert main.cpp:%d" % line)
+        self.expect("\^done,bkpt={number=\"1\"")
+        self.runCmd("-exec-run")
+        self.expect("\^running");
+        self.expect("\*stopped,reason=\"breakpoint-hit\"")
+
+        # Setup variable
+        self.runCmd("-var-create var_a * a");
+        self.expect("\^done,name=\"var_a\",numchild=\"0\",value=\"10\",type=\"int\",thread-id=\"1\",has_more=\"0\"")
+
+        # Test default output
+        self.runCmd("-var-evaluate-expression var_a");
+        self.expect("\^done,value=\"10\"");
+
+        # Test hex output
+        self.runCmd("-gdb-set output-radix 16");
+        self.expect("\^done");
+        self.runCmd("-var-evaluate-expression var_a");
+        self.expect("\^done,value=\"0xa\"");
+
+        # Test octal output
+        self.runCmd("-gdb-set output-radix 8");
+        self.expect("\^done");
+        self.runCmd("-var-evaluate-expression var_a");
+        self.expect("\^done,value=\"012\"");
+
+        # Test decimal output
+        self.runCmd("-gdb-set output-radix 10");
+        self.expect("\^done");
+        self.runCmd("-var-evaluate-expression var_a");
+        self.expect("\^done,value=\"10\"");
+
 if __name__ == '__main__':
     unittest2.main()
Index: lldb/trunk/test/tools/lldb-mi/main.cpp
===================================================================
--- lldb/trunk/test/tools/lldb-mi/main.cpp
+++ lldb/trunk/test/tools/lldb-mi/main.cpp
@@ -12,6 +12,8 @@
 int
 main(int argc, char const *argv[])
 {
-    printf("argc=%d\n", argc);
+    int a  = 10;
+
+    printf("argc=%d\n", argc); // BP_printf
     return 0;
 }
Index: lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.h
===================================================================
--- lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.h
+++ lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.h
@@ -71,6 +71,7 @@
     bool GetOptionFn(const CMIUtilString &vrGdbOptionName, FnGdbOptionPtr &vrwpFn) const;
     bool OptionFnTargetAsync(const CMIUtilString::VecString_t &vrWords);
     bool OptionFnSolibSearchPath(const CMIUtilString::VecString_t &vrWords);
+    bool OptionFnOutputRadix(const CMIUtilString::VecString_t &vrWords);
     bool OptionFnFallback(const CMIUtilString::VecString_t &vrWords);
 
     // Attributes:
Index: lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.cpp
===================================================================
--- lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.cpp
+++ lldb/trunk/tools/lldb-mi/MICmdCmdGdbSet.cpp
@@ -22,6 +22,7 @@
 const CMICmdCmdGdbSet::MapGdbOptionNameToFnGdbOptionPtr_t CMICmdCmdGdbSet::ms_mapGdbOptionNameToFnGdbOptionPtr = {
     {"target-async", &CMICmdCmdGdbSet::OptionFnTargetAsync},
     // { "auto-solib-add", &CMICmdCmdGdbSet::OptionFnAutoSolibAdd },    // Example code if need to implement GDB set other options
+    {"output-radix", &CMICmdCmdGdbSet::OptionFnOutputRadix},
     {"solib-search-path", &CMICmdCmdGdbSet::OptionFnSolibSearchPath},
     {"fallback", &CMICmdCmdGdbSet::OptionFnFallback}};
 
@@ -288,6 +289,58 @@
 }
 
 //++ ------------------------------------------------------------------------------------
+// Details: Carry out work to complete the GDB set option 'output-radix' to prepare
+//          and send back information asked for.
+// Type:    Method.
+// Args:    vrWords - (R) List of additional parameters used by this option.
+// Return:  MIstatus::success - Functional succeeded.
+//          MIstatus::failure - Functional failed.
+// Throws:  None.
+//--
+bool
+CMICmdCmdGdbSet::OptionFnOutputRadix(const CMIUtilString::VecString_t &vrWords)
+{
+    // Check we have at least one argument
+    if (vrWords.size() < 1)
+    {
+        m_bGbbOptionFnHasError = true;
+        m_strGdbOptionFnError = MIRSRC(IDS_CMD_ERR_GDBSET_OPT_SOLIBSEARCHPATH);
+        return MIstatus::failure;
+    }
+    const CMIUtilString &rStrValOutputRadix(vrWords[0]);
+    
+    CMICmnLLDBDebugSessionInfoVarObj::varFormat_e  format = CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Invalid;
+    MIint64 radix;
+    if (rStrValOutputRadix.ExtractNumber(radix))
+    {
+        switch (radix)
+        {
+        case 8:
+            format = CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Octal;
+            break;
+        case 10:
+            format = CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Natural;
+            break;
+        case 16:
+            format = CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Hex;
+            break;
+        default:
+            format = CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Invalid;
+            break;
+        }
+    }
+    if (format == CMICmnLLDBDebugSessionInfoVarObj::eVarFormat_Invalid)
+    {
+        m_bGbbOptionFnHasError = false;
+        SetError(CMIUtilString::Format(MIRSRC(IDS_DBGSESSION_ERR_SHARED_DATA_ADD), m_cmdData.strMiCmd.c_str(), "Output Radix"));
+        return MIstatus::failure;
+    }
+    CMICmnLLDBDebugSessionInfoVarObj::VarObjSetFormat(format);
+    
+    return MIstatus::success;
+}
+
+//++ ------------------------------------------------------------------------------------
 // Details: Carry out work to complete the GDB set option to prepare and send back the
 //          requested information.
 // Type:    Method.
Index: lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.h
===================================================================
--- lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.h
+++ lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.h
@@ -67,6 +67,7 @@
     static MIuint VarObjIdGet(void);
     static void VarObjIdResetToZero(void);
     static void VarObjClear(void);
+    static void VarObjSetFormat(varFormat_e eDefaultFormat);
 
     // Methods:
   public:
@@ -117,6 +118,7 @@
     static const MIchar *ms_aVarFormatChars[];
     static MapKeyToVarObj_t ms_mapVarIdToVarObj;
     static MIuint ms_nVarUniqueId;
+    static varFormat_e ms_eDefaultFormat;    // overrides "natural" format
     //
     // *** Upate the copy move constructors and assignment operator ***
     varFormat_e m_eVarFormat;
Index: lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.cpp
===================================================================
--- lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.cpp
+++ lldb/trunk/tools/lldb-mi/MICmnLLDBDebugSessionInfoVarObj.cpp
@@ -23,6 +23,7 @@
     "<Invalid var format>", "t", "o", "d", "x", "N"};
 CMICmnLLDBDebugSessionInfoVarObj::MapKeyToVarObj_t CMICmnLLDBDebugSessionInfoVarObj::ms_mapVarIdToVarObj;
 MIuint CMICmnLLDBDebugSessionInfoVarObj::ms_nVarUniqueId = 0; // Index from 0
+CMICmnLLDBDebugSessionInfoVarObj::varFormat_e CMICmnLLDBDebugSessionInfoVarObj::ms_eDefaultFormat = eVarFormat_Natural;
 
 //++ ------------------------------------------------------------------------------------
 // Details: CMICmnLLDBDebugSessionInfoVarObj constructor.
@@ -302,8 +303,13 @@
                                                      const CMICmnLLDBDebugSessionInfoVarObj::varFormat_e veVarFormat)
 {
     CMIUtilString strFormattedValue;
+    CMICmnLLDBDebugSessionInfoVarObj::varFormat_e veFormat = veVarFormat;
+    if (ms_eDefaultFormat != eVarFormat_Invalid && veVarFormat == eVarFormat_Natural)
+    {
+        veFormat = ms_eDefaultFormat;
+    }
 
-    switch (veVarFormat)
+    switch (veFormat)
     {
         case eVarFormat_Binary:
             strFormattedValue = CMIUtilString::FormatBinary(vnValue);
@@ -422,6 +428,20 @@
 }
 
 //++ ------------------------------------------------------------------------------------
+// Details: Default format is globally used as the data format when "natural" is in effect, that is, this overrides the default
+// Type:    Static method.
+// Args:    None.
+// Returns: None.
+// Throws:  None.
+//--
+void
+CMICmnLLDBDebugSessionInfoVarObj::VarObjSetFormat(varFormat_e eDefaultFormat)
+{
+    ms_eDefaultFormat = eDefaultFormat;
+}
+
+
+//++ ------------------------------------------------------------------------------------
 // Details: A count is kept of the number of var value objects created. This is count is
 //          used to ID the var value object. Increment the count by 1.
 // Type:    Static method.