From 265fa9fa399225509fe2f9b5b24c3619e30aa411 Mon Sep 17 00:00:00 2001
From: rsun3 <rsun3@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Wed, 22 Feb 2012 02:39:57 +0000
Subject: [PATCH] MdePkg: Add a new macro VA_COPY for variable argument
 support. Fix a bug in the UefiLib instance that there is a non portable
 assumption that Marker is copied when passed to a function.

Signed-off-by: rsun3
Reviewed-by: mdkinney


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13025 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Include/Base.h                 | 20 +++++++++++++++++++-
 MdePkg/Library/UefiLib/UefiLibPrint.c |  5 ++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index 4fcc3a1bf6..66fc5d271b 100644
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -6,7 +6,7 @@
   environment. There are a set of base libraries in the Mde Package that can
   be used to implement base modules.
 
-Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
 Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
@@ -393,6 +393,7 @@ struct _LIST_ENTRY {
 //  VA_END (VA_LIST Marker) - Clear Marker
 //  VA_ARG (VA_LIST Marker, var arg size) - Use Marker to get an argument from
 //    the ... list. You must know the size and pass it in this macro.
+//  VA_COPY (VA_LIST Dest, VA_LIST Start) - Initialize Dest as a copy of Start.
 //
 //  example:
 //
@@ -454,6 +455,8 @@ struct _LIST_ENTRY {
 
 #define VA_END(Marker)                ((void)0)
 
+#define VA_COPY(Dest, Start)          __va_copy (Dest, Start)
+
 #elif defined(__GNUC__) && !defined(NO_BUILTIN_VA_FUNCS)
 //
 // Use GCC built-in macros for variable argument lists.
@@ -471,6 +474,8 @@ typedef __builtin_va_list VA_LIST;
 
 #define VA_END(Marker)               __builtin_va_end (Marker)
 
+#define VA_COPY(Dest, Start)         __builtin_va_copy (Dest, Start)
+
 #else
 ///
 /// Variable used to traverse the list of arguments. This type can vary by
@@ -526,6 +531,19 @@ typedef CHAR8 *VA_LIST;
 **/
 #define VA_END(Marker)      (Marker = (VA_LIST) 0)
 
+/**
+  Initializes a VA_LIST as a copy of an existing VA_LIST.
+
+  This macro initializes Dest as a copy of Start, as if the VA_START macro had been applied to Dest
+  followed by the same sequence of uses of the VA_ARG macro as had previously been used to reach
+  the present state of Start. 
+
+  @param   Dest   VA_LIST used to traverse the list of arguments.
+  @param   Start  VA_LIST used to traverse the list of arguments.
+
+**/
+#define VA_COPY(Dest, Start)  ((void)((Dest) = (Start)))
+
 #endif
 
 ///
diff --git a/MdePkg/Library/UefiLib/UefiLibPrint.c b/MdePkg/Library/UefiLib/UefiLibPrint.c
index 6eadc120c8..1bf6d26821 100644
--- a/MdePkg/Library/UefiLib/UefiLibPrint.c
+++ b/MdePkg/Library/UefiLib/UefiLibPrint.c
@@ -742,8 +742,11 @@ CatVSPrint (
   UINTN   CharactersRequired;
   UINTN   SizeRequired;
   CHAR16  *BufferToReturn;
+  VA_LIST ExtraMarker;
 
-  CharactersRequired = SPrintLength(FormatString, Marker);
+  VA_COPY (ExtraMarker, Marker);
+  CharactersRequired = SPrintLength(FormatString, ExtraMarker);
+  VA_END (ExtraMarker);
 
   if (String != NULL) {
     SizeRequired = StrSize(String) + (CharactersRequired * sizeof(CHAR16));
-- 
2.39.2