Add GetCurrentLanguage() to HiiLib in MdeModulePkg

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@6758 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Include/Library/HiiLib.h

@@ -497,4 +497,26 @@ Rfc3066ToIso639 (
   CHAR8  *SupportedLanguages
   );
 
+
+/**
+  Determine what is the current language setting. The space reserved for Lang
+  must be at least RFC_3066_ENTRY_SIZE bytes;
+
+  If Lang is NULL, then ASSERT.
+
+  @param  Lang                   Pointer of system language. Lang will always be filled with 
+                                         a valid RFC 3066 language string. If "PlatformLang" is not
+                                         set in the system, the default language specifed by PcdUefiVariableDefaultPlatformLang
+                                         is returned.
+
+  @return  EFI_SUCCESS     If the EFI Variable with "PlatformLang" is set and return in Lang.
+  @return  EFI_NOT_FOUND If the EFI Variable with "PlatformLang" is not set, but a valid default language is return in Lang.
+
+**/
+EFI_STATUS
+EFIAPI
+GetCurrentLanguage (
+  OUT     CHAR8               *Lang
+  );
+
 #endif