[iQue] Build some C files with EGCS (#2396)

include/libc/stdarg.h

@@ -1,16 +1,16 @@
 #ifndef STDARG_H
 #define STDARG_H
 
-// When building with GCC, use the official vaarg macros to avoid warnings and possibly bad codegen.
+// When building with modern GCC, use the official vaarg macros to avoid warnings and possibly bad codegen.
 
-#ifdef __GNUC__
+#if __GNUC__ >= 3
 
 #define va_list  __builtin_va_list
 #define va_start __builtin_va_start
 #define va_arg   __builtin_va_arg
 #define va_end   __builtin_va_end
 
-#else
+#elif defined(__sgi) /* IDO */
 
 #ifndef _VA_LIST_
 # define _VA_LIST_
@@ -52,6 +52,28 @@ typedef char* va_list;
 /* No cleanup processing is required for the end of a varargs list: */
 #define va_end(__list)
 
-#endif /* __GNUC__ */
+#else /* EGCS */
+
+typedef char * __gnuc_va_list;
+
+#define __va_rounded_size(__TYPE)  \
+  (((sizeof (__TYPE) + sizeof (int) - 1) / sizeof (int)) * sizeof (int))
+
+#define va_start(__AP, __LASTARG) \
+  (__AP = (__gnuc_va_list) __builtin_next_arg (__LASTARG))
+
+#define va_end(__AP)    ((void)0)
+
+/* We cast to void * and then to TYPE * because this avoids
+   a warning about increasing the alignment requirement.  */
+#define va_arg(__AP, __type)                                                \
+  ((__type *) (void *) (__AP = (char *) ((__alignof__(__type) > 4           \
+                                ? ((__PTRDIFF_TYPE__)__AP + 8 - 1) & -8     \
+                                : ((__PTRDIFF_TYPE__)__AP + 4 - 1) & -4)    \
+                                         + __va_rounded_size(__type))))[-1]
+
+typedef __gnuc_va_list va_list;
+
+#endif
 
 #endif