The GCC compiler’s behavior is different than the Microsoft compilers for statically linked vararg functions. The GCC compilers do provide __builtin_ functions for accessing varargs. we should use these intrinsic functions with GCC

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8260 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 15 insertions, 0 deletions

diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index 00cce609f5..69ebba345e 100644
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -332,7 +332,20 @@ struct _LIST_ENTRY {
 //    return Result

 //  }

 //

+#if defined(__GNUC__)

+//

+//  In GCC compiler, its behavior for statically linked varargs is different with MSFT tool chain.

+//  Should use __builtin_* intrinsic functions provided by GCC compiler to access varargs.

+//

+typedef __builtin_va_list VA_LIST;

+

+#define VA_START(Marker, Parameter)  __builtin_va_start(Marker, Parameter)

+

+#define VA_ARG(Marker, TYPE)         __builtin_va_arg(Marker, TYPE)

 

+#define VA_END(Marker)               __builtin_va_end(Marker)

+

+#else

 /**

   Return the size of argument that has been aligned to sizeof (UINTN).

 

@@ -394,6 +407,8 @@ typedef CHAR8 *VA_LIST;
 **/

 #define VA_END(Marker)      (Marker = (VA_LIST) 0)

 

+#endif

+

 /**

   Macro that returns the byte offset of a field in a data structure.