MdePkg/Include: Add VA list support for VS2017/ARM

VA_START, VA_END and VA_COPY are the same as the generic macros.
VA_ARG was reverse engineered from MS ARM assembly output.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Liming Gao <liming.gao@intel.com>

diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index b01e03a03b960831ed4b5686e31ffde68c87efbe..a94182f08886d8297eb0cf5a4d7aa873654eca64 100644 (file)
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -668,6 +668,19 @@ struct _LIST_ENTRY {
 \r
 #define VA_COPY(Dest, Start)          __va_copy (Dest, Start)\r
 \r
+#elif defined(_M_ARM)\r
+//\r
+// MSFT ARM variable argument list support.\r
+// Same as the generic macros below, except for VA_ARG that needs extra adjustment.\r
+//\r
+\r
+typedef char* VA_LIST;\r
+\r
+#define VA_START(Marker, Parameter)     (Marker = (VA_LIST) ((UINTN) & (Parameter) + _INT_SIZE_OF(Parameter)))\r
+#define VA_ARG(Marker, TYPE)            (*(TYPE *) ((Marker += _INT_SIZE_OF(TYPE) + ((-(INTN)Marker) & (sizeof(TYPE) - 1))) - _INT_SIZE_OF (TYPE)))\r
+#define VA_END(Marker)                  (Marker = (VA_LIST) 0)\r
+#define VA_COPY(Dest, Start)            ((void)((Dest) = (Start)))\r
+\r
 #elif defined(__GNUC__)\r
 \r
 #if defined(MDE_CPU_X64) && !defined(NO_MSABI_VA_FUNCS)\r