Index: lldb/trunk/include/lldb/Host/Host.h
===================================================================
--- lldb/trunk/include/lldb/Host/Host.h
+++ lldb/trunk/include/lldb/Host/Host.h
@@ -259,7 +259,7 @@
                      int *signo_ptr,                // Pass NULL if you don't want the signal that caused the process to exit
                      std::string *command_output,   // Pass NULL if you don't want the command output
                      uint32_t timeout_sec,
-                     const char *shell = LLDB_DEFAULT_SHELL);
+                     bool run_in_default_shell = true);
     
     static lldb::DataBufferSP
     GetAuxvData (lldb_private::Process *process);
Index: lldb/trunk/include/lldb/Host/posix/HostInfoPosix.h
===================================================================
--- lldb/trunk/include/lldb/Host/posix/HostInfoPosix.h
+++ lldb/trunk/include/lldb/Host/posix/HostInfoPosix.h
@@ -10,6 +10,7 @@
 #ifndef lldb_Host_posix_HostInfoPosix_h_
 #define lldb_Host_posix_HostInfoPosix_h_
 
+#include "lldb/Host/FileSpec.h"
 #include "lldb/Host/HostInfoBase.h"
 
 namespace lldb_private
@@ -30,6 +31,8 @@
     static uint32_t GetEffectiveUserID();
     static uint32_t GetEffectiveGroupID();
 
+    static FileSpec GetDefaultShell();
+
   protected:
     static bool ComputeSupportExeDirectory(FileSpec &file_spec);
     static bool ComputeHeaderDirectory(FileSpec &file_spec);
Index: lldb/trunk/include/lldb/Host/windows/HostInfoWindows.h
===================================================================
--- lldb/trunk/include/lldb/Host/windows/HostInfoWindows.h
+++ lldb/trunk/include/lldb/Host/windows/HostInfoWindows.h
@@ -33,6 +33,7 @@
     static bool GetOSKernelDescription(std::string &s);
     static bool GetHostname(std::string &s);
     static FileSpec GetProgramFileSpec();
+    static FileSpec GetDefaultShell();
 
   protected:
     static bool ComputePythonDirectory(FileSpec &file_spec);
Index: lldb/trunk/include/lldb/Target/ProcessLaunchInfo.h
===================================================================
--- lldb/trunk/include/lldb/Target/ProcessLaunchInfo.h
+++ lldb/trunk/include/lldb/Target/ProcessLaunchInfo.h
@@ -15,6 +15,7 @@
 
 // LLDB Headers
 #include "lldb/Core/Flags.h"
+#include "lldb/Host/FileSpec.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Target/FileAction.h"
 #include "lldb/Target/ProcessInfo.h"
@@ -105,11 +106,11 @@
         void
         SetProcessPluginName (const char *plugin);
 
-        const char *
+        const FileSpec &
         GetShell () const;
 
         void
-        SetShell (const char * path);
+        SetShell (const FileSpec &shell);
 
         uint32_t
         GetResumeCount () const
@@ -215,7 +216,7 @@
     protected:
         std::string m_working_dir;
         std::string m_plugin_name;
-        std::string m_shell;
+        FileSpec m_shell;
         Flags m_flags;       // Bitwise OR of bits from lldb::LaunchFlags
         std::vector<FileAction> m_file_actions; // File actions for any other files
         std::shared_ptr<lldb_utility::PseudoTerminal> m_pty;
Index: lldb/trunk/include/lldb/lldb-defines.h
===================================================================
--- lldb/trunk/include/lldb/lldb-defines.h
+++ lldb/trunk/include/lldb/lldb-defines.h
@@ -49,11 +49,6 @@
 // LLDB defines
 //----------------------------------------------------------------------
 #define LLDB_GENERIC_ERROR              UINT32_MAX
-#if defined(_WIN32)
-#define LLDB_DEFAULT_SHELL              "cmd.exe"
-#else
-#define LLDB_DEFAULT_SHELL              "/bin/sh"
-#endif
 
 //----------------------------------------------------------------------
 // Breakpoints
Index: lldb/trunk/source/API/SBTarget.cpp
===================================================================
--- lldb/trunk/source/API/SBTarget.cpp
+++ lldb/trunk/source/API/SBTarget.cpp
@@ -236,13 +236,16 @@
 const char *
 SBLaunchInfo::GetShell ()
 {
-    return m_opaque_sp->GetShell();
+    // Constify this string so that it is saved in the string pool.  Otherwise
+    // it would be freed when this function goes out of scope.
+    ConstString shell(m_opaque_sp->GetShell().GetPath().c_str());
+    return shell.AsCString();
 }
 
 void
 SBLaunchInfo::SetShell (const char * path)
 {
-    m_opaque_sp->SetShell (path);
+    m_opaque_sp->SetShell (FileSpec(path, false));
 }
 
 uint32_t
Index: lldb/trunk/source/Host/common/Host.cpp
===================================================================
--- lldb/trunk/source/Host/common/Host.cpp
+++ lldb/trunk/source/Host/common/Host.cpp
@@ -550,14 +550,14 @@
                        int *signo_ptr,
                        std::string *command_output_ptr,
                        uint32_t timeout_sec,
-                       const char *shell)
+                       bool run_in_default_shell)
 {
     Error error;
     ProcessLaunchInfo launch_info;
-    if (shell && shell[0])
+    if (run_in_default_shell)
     {
         // Run the command in a shell
-        launch_info.SetShell(shell);
+        launch_info.SetShell(HostInfo::GetDefaultShell());
         launch_info.GetArguments().AppendArgument(command);
         const bool localhost = true;
         const bool will_debug = false;
Index: lldb/trunk/source/Host/posix/HostInfoPosix.cpp
===================================================================
--- lldb/trunk/source/Host/posix/HostInfoPosix.cpp
+++ lldb/trunk/source/Host/posix/HostInfoPosix.cpp
@@ -125,6 +125,12 @@
     return getegid();
 }
 
+FileSpec
+HostInfoPosix::GetDefaultShell()
+{
+    return FileSpec("/bin/sh", false);
+}
+
 bool
 HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec)
 {
Index: lldb/trunk/source/Host/windows/HostInfoWindows.cpp
===================================================================
--- lldb/trunk/source/Host/windows/HostInfoWindows.cpp
+++ lldb/trunk/source/Host/windows/HostInfoWindows.cpp
@@ -96,6 +96,12 @@
     return m_program_filespec;
 }
 
+FileSpec
+HostInfoWindows::GetDefaultShell()
+{
+    return FileSpec(::getenv("ComSpec"), false);
+}
+
 bool
 HostInfoWindows::ComputePythonDirectory(FileSpec &file_spec)
 {
Index: lldb/trunk/source/Interpreter/CommandInterpreter.cpp
===================================================================
--- lldb/trunk/source/Interpreter/CommandInterpreter.cpp
+++ lldb/trunk/source/Interpreter/CommandInterpreter.cpp
@@ -339,7 +339,11 @@
 #if defined (__arm__) || defined (__arm64__) || defined (__aarch64__)
         ProcessAliasOptionsArgs (cmd_obj_sp, "--", alias_arguments_vector_sp);
 #else
-        ProcessAliasOptionsArgs (cmd_obj_sp, "--shell=" LLDB_DEFAULT_SHELL " --", alias_arguments_vector_sp);
+        std::string shell_option;
+        shell_option.append("--shell=");
+        shell_option.append(HostInfo::GetDefaultShell().GetPath());
+        shell_option.append(" --");
+        ProcessAliasOptionsArgs (cmd_obj_sp, shell_option.c_str(), alias_arguments_vector_sp);
 #endif
         AddAlias ("r", cmd_obj_sp);
         AddAlias ("run", cmd_obj_sp);
Index: lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp
===================================================================
--- lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp
+++ lldb/trunk/source/Plugins/Platform/Linux/PlatformLinux.cpp
@@ -554,17 +554,18 @@
     }
 
     // If we're not launching a shell, we're done.
-    const char *shell = launch_info.GetShell();
-    if (shell == NULL)
+    const FileSpec &shell = launch_info.GetShell();
+    if (!shell)
         return resume_count;
 
+    std::string shell_string = shell.GetPath();
     // We're in a shell, so for sure we have to resume past the shell exec.
     ++resume_count;
 
     // Figure out what shell we're planning on using.
-    const char *shell_name = strrchr (shell, '/');
+    const char *shell_name = strrchr (shell_string.c_str(), '/');
     if (shell_name == NULL)
-        shell_name = shell;
+        shell_name = shell_string.c_str();
     else
         shell_name++;
 
Index: lldb/trunk/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
===================================================================
--- lldb/trunk/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
+++ lldb/trunk/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
@@ -1146,13 +1146,14 @@
 int32_t
 PlatformDarwin::GetResumeCountForLaunchInfo (ProcessLaunchInfo &launch_info)
 {
-    const char *shell = launch_info.GetShell();
-    if (shell == NULL)
+    const FileSpec &shell = launch_info.GetShell();
+    if (!shell)
         return 1;
         
-    const char *shell_name = strrchr (shell, '/');
+    std::string shell_string = shell.GetPath();
+    const char *shell_name = strrchr (shell_string.c_str(), '/');
     if (shell_name == NULL)
-        shell_name = shell;
+        shell_name = shell_string.c_str();
     else
         shell_name++;
     
Index: lldb/trunk/source/Target/Platform.cpp
===================================================================
--- lldb/trunk/source/Target/Platform.cpp
+++ lldb/trunk/source/Target/Platform.cpp
@@ -1063,10 +1063,14 @@
             const bool first_arg_is_full_shell_command = false;
             uint32_t num_resumes = GetResumeCountForLaunchInfo (launch_info);
             if (log)
+            {
+                const FileSpec &shell = launch_info.GetShell();
+                const char *shell_str = (shell) ? shell.GetPath().c_str() : "<null>";
                 log->Printf ("Platform::%s GetResumeCountForLaunchInfo() returned %" PRIu32 ", shell is '%s'",
                              __FUNCTION__,
                              num_resumes,
-                             launch_info.GetShell () ? launch_info.GetShell () : "<null>");
+                             shell_str);
+            }
 
             if (!launch_info.ConvertArgumentsForLaunchingInShell (error,
                                                                   is_localhost,
Index: lldb/trunk/source/Target/Process.cpp
===================================================================
--- lldb/trunk/source/Target/Process.cpp
+++ lldb/trunk/source/Target/Process.cpp
@@ -480,9 +480,9 @@
 
         case 'c':
             if (option_arg && option_arg[0])
-                launch_info.SetShell (option_arg);
+                launch_info.SetShell (FileSpec(option_arg, false));
             else
-                launch_info.SetShell (LLDB_DEFAULT_SHELL);
+                launch_info.SetShell (HostInfo::GetDefaultShell());
             break;
             
         case 'v':
Index: lldb/trunk/source/Target/ProcessLaunchInfo.cpp
===================================================================
--- lldb/trunk/source/Target/ProcessLaunchInfo.cpp
+++ lldb/trunk/source/Target/ProcessLaunchInfo.cpp
@@ -25,7 +25,6 @@
     ProcessInfo(),
     m_working_dir (),
     m_plugin_name (),
-    m_shell (),
     m_flags (0),
     m_file_actions (),
     m_pty (new lldb_utility::PseudoTerminal),
@@ -42,7 +41,6 @@
     ProcessInfo(),
     m_working_dir(),
     m_plugin_name(),
-    m_shell(),
     m_flags(launch_flags),
     m_file_actions(),
     m_pty(new lldb_utility::PseudoTerminal),
@@ -181,27 +179,23 @@
         m_plugin_name.clear();
 }
 
-const char *
+const FileSpec &
 ProcessLaunchInfo::GetShell () const
 {
-    if (m_shell.empty())
-        return NULL;
-    return m_shell.c_str();
+    return m_shell;
 }
 
 void
-ProcessLaunchInfo::SetShell (const char * path)
+ProcessLaunchInfo::SetShell (const FileSpec &shell)
 {
-    if (path && path[0])
+    m_shell = shell;
+    if (m_shell)
     {
-        m_shell.assign (path);
+        m_shell.ResolveExecutableLocation();
         m_flags.Set (lldb::eLaunchFlagLaunchInShell);
     }
     else
-    {
-        m_shell.clear();
         m_flags.Clear (lldb::eLaunchFlagLaunchInShell);
-    }
 }
 
 void
@@ -220,7 +214,7 @@
     ProcessInfo::Clear();
     m_working_dir.clear();
     m_plugin_name.clear();
-    m_shell.clear();
+    m_shell.Clear();
     m_flags.Clear();
     m_file_actions.clear();
     m_resume_count = 0;
@@ -388,34 +382,17 @@
 
     if (GetFlags().Test (eLaunchFlagLaunchInShell))
     {
-        const char *shell_executable = GetShell();
-        if (shell_executable)
+        if (m_shell)
         {
             char shell_resolved_path[PATH_MAX];
-
-            if (localhost)
-            {
-                FileSpec shell_filespec (shell_executable, true);
-
-                if (!shell_filespec.Exists())
-                {
-                    // Resolve the path in case we just got "bash", "sh" or "tcsh"
-                    if (!shell_filespec.ResolveExecutableLocation ())
-                    {
-                        error.SetErrorStringWithFormat("invalid shell path '%s'", shell_executable);
-                        return false;
-                    }
-                }
-                shell_filespec.GetPath (shell_resolved_path, sizeof(shell_resolved_path));
-                shell_executable = shell_resolved_path;
-            }
+            std::string shell_executable = m_shell.GetPath();
 
             const char **argv = GetArguments().GetConstArgumentVector ();
             if (argv == NULL || argv[0] == NULL)
                 return false;
             Args shell_arguments;
             std::string safe_arg;
-            shell_arguments.AppendArgument (shell_executable);
+            shell_arguments.AppendArgument (shell_executable.c_str());
             shell_arguments.AppendArgument ("-c");
             StreamString shell_command;
             if (will_debug)
@@ -494,7 +471,7 @@
                 }
             }
             shell_arguments.AppendArgument (shell_command.GetString().c_str());
-            m_executable.SetFile(shell_executable, false);
+            m_executable = m_shell;
             m_arguments = shell_arguments;
             return true;
         }
Index: lldb/trunk/source/Target/Target.cpp
===================================================================
--- lldb/trunk/source/Target/Target.cpp
+++ lldb/trunk/source/Target/Target.cpp
@@ -35,6 +35,7 @@
 #include "lldb/Core/ValueObject.h"
 #include "lldb/Expression/ClangASTSource.h"
 #include "lldb/Expression/ClangUserExpression.h"
+#include "lldb/Host/FileSpec.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Interpreter/CommandReturnObject.h"
@@ -2477,7 +2478,7 @@
             }
             else if (state == eStateExited)
             {
-                bool with_shell = launch_info.GetShell();
+                bool with_shell = !!launch_info.GetShell();
                 const int exit_status = m_process_sp->GetExitStatus();
                 const char *exit_desc = m_process_sp->GetExitDescription();
 #define LAUNCH_SHELL_MESSAGE "\n'r' and 'run' are aliases that default to launching through a shell.\nTry launching without going through a shell by using 'process launch'."