Initial revision

include/stdarg.h

@@ -0,0 +1,90 @@
+/* The <stdarg.h> header is ANSI's way to handle variable numbers of params.
+ * Some programming languages require a function that is declared with n
+ * parameters to be called with n parameters.  C does not.  A function may
+ * called with more parameters than it is declared with.  The well-known
+ * printf function, for example, may have arbitrarily many parameters.
+ * The question arises how one can access all the parameters in a portable
+ * way.  The C standard defines three macros that programs can use to
+ * advance through the parameter list.  The definition of these macros for
+ * MINIX are given in this file.  The three macros are:
+ *
+ *	va_start(ap, parmN)	prepare to access parameters
+ *	va_arg(ap, type)	get next parameter value and type
+ *	va_end(ap)		access is finished
+ *
+ * Ken Thompson's famous line from V6 UNIX is equally applicable to this file:
+ *
+ *	"You are not expected to understand this"
+ *
+ */
+
+#ifndef _STDARG_H
+#define _STDARG_H
+
+
+#ifdef __GNUC__
+/* The GNU C-compiler uses its own, but similar varargs mechanism. */
+
+typedef char *va_list;
+
+/* Amount of space required in an argument list for an arg of type TYPE.
+ * TYPE may alternatively be an expression whose type is used.
+ */
+
+#define __va_rounded_size(TYPE)  \
+  (((sizeof (TYPE) + sizeof (int) - 1) / sizeof (int)) * sizeof (int))
+
+#if __GNUC__ < 2
+
+#ifndef __sparc__
+#define va_start(AP, LASTARG)                                           \
+ (AP = ((char *) &(LASTARG) + __va_rounded_size (LASTARG)))
+#else
+#define va_start(AP, LASTARG)                                           \
+ (__builtin_saveregs (),                                                \
+  AP = ((char *) &(LASTARG) + __va_rounded_size (LASTARG)))
+#endif
+
+void va_end (va_list);          /* Defined in gnulib */
+#define va_end(AP)
+
+#define va_arg(AP, TYPE)                                                \
+ (AP += __va_rounded_size (TYPE),                                       \
+  *((TYPE *) (AP - __va_rounded_size (TYPE))))
+
+#else	/* __GNUC__ >= 2 */
+
+#ifndef __sparc__
+#define va_start(AP, LASTARG) 						\
+ (AP = ((char *) __builtin_next_arg ()))
+#else
+#define va_start(AP, LASTARG)					\
+  (__builtin_saveregs (), AP = ((char *) __builtin_next_arg ()))
+#endif
+
+void va_end (va_list);		/* Defined in libgcc.a */
+#define va_end(AP)
+
+#define va_arg(AP, TYPE)						\
+ (AP = ((char *) (AP)) += __va_rounded_size (TYPE),			\
+  *((TYPE *) ((char *) (AP) - __va_rounded_size (TYPE))))
+
+#endif	/* __GNUC__ >= 2 */
+
+#else	/* not __GNUC__ */
+
+
+typedef char *va_list;
+
+#define __vasz(x)		((sizeof(x)+sizeof(int)-1) & ~(sizeof(int) -1))
+
+#define va_start(ap, parmN)	((ap) = (va_list)&parmN + __vasz(parmN))
+#define va_arg(ap, type)      \
+  (*((type *)((va_list)((ap) = (void *)((va_list)(ap) + __vasz(type))) \
+						    - __vasz(type))))
+#define va_end(ap)
+
+
+#endif /* __GNUC__ */
+
+#endif /* _STDARG_H */