mirror of
https://github.com/MariaDB/server.git
synced 2025-01-18 21:12:26 +01:00
140 lines
4.8 KiB
C
140 lines
4.8 KiB
C
|
/******************************************************************************
|
|||
|
|
* *
|
|||
|
|
* N O T I C E *
|
|||
|
|
* *
|
|||
|
|
* Copyright Abandoned, 1987, Fred Fish *
|
|||
|
|
* *
|
|||
|
|
* *
|
|||
|
|
* This previously copyrighted work has been placed into the public *
|
|||
|
|
* domain by the author and may be freely used for any purpose, *
|
|||
|
|
* private or commercial. *
|
|||
|
|
* *
|
|||
|
|
* Because of the number of inquiries I was receiving about the use *
|
|||
|
|
* of this product in commercially developed works I have decided to *
|
|||
|
|
* simply make it public domain to further its unrestricted use. I *
|
|||
|
|
* specifically would be most happy to see this material become a *
|
|||
|
|
* part of the standard Unix distributions by AT&T and the Berkeley *
|
|||
|
|
* Computer Science Research Group, and a standard part of the GNU *
|
|||
|
|
* system from the Free Software Foundation. *
|
|||
|
|
* *
|
|||
|
|
* I would appreciate it, as a courtesy, if this notice is left in *
|
|||
|
|
* all copies and derivative works. Thank you. *
|
|||
|
|
* *
|
|||
|
|
* The author makes no warranty of any kind with respect to this *
|
|||
|
|
* product and explicitly disclaims any implied warranties of mer- *
|
|||
|
|
* chantability or fitness for any particular purpose. *
|
|||
|
|
* *
|
|||
|
|
******************************************************************************
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* FILE
|
|||
|
|
*
|
|||
|
|
* vargs.h include file for environments without varargs.h
|
|||
|
|
*
|
|||
|
|
* SCCS
|
|||
|
|
*
|
|||
|
|
* @(#)vargs.h 1.2 5/8/88
|
|||
|
|
*
|
|||
|
|
* SYNOPSIS
|
|||
|
|
*
|
|||
|
|
* #include "vargs.h"
|
|||
|
|
*
|
|||
|
|
* DESCRIPTION
|
|||
|
|
*
|
|||
|
|
* This file implements a varargs macro set for use in those
|
|||
|
|
* environments where there is no system supplied varargs. This
|
|||
|
|
* generally works because systems which don't supply a varargs
|
|||
|
|
* package are precisely those which don't strictly need a varargs
|
|||
|
|
* package. Using this one then allows us to minimize source
|
|||
|
|
* code changes. So in some sense, this is a "portable" varargs
|
|||
|
|
* since it is only used for convenience, when it is not strictly
|
|||
|
|
* needed.
|
|||
|
|
*
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* These macros allow us to rebuild an argument list on the stack
|
|||
|
|
* given only a va_list. We can use these to fake a function like
|
|||
|
|
* vfprintf, which gets a fixed number of arguments, the last of
|
|||
|
|
* which is a va_list, by rebuilding a stack and calling the variable
|
|||
|
|
* argument form fprintf. Of course this only works when vfprintf
|
|||
|
|
* is not available in the host environment, and thus is not available
|
|||
|
|
* for fprintf to call (which would give us an infinite loop).
|
|||
|
|
*
|
|||
|
|
* Note that ARGS_TYPE is a long, which lets us get several bytes
|
|||
|
|
* at a time while also preventing lots of "possible pointer alignment
|
|||
|
|
* problem" messages from lint. The messages are valid, because this
|
|||
|
|
* IS nonportable, but then we should only be using it in very
|
|||
|
|
* nonrestrictive environments, and using the real varargs where it
|
|||
|
|
* really counts.
|
|||
|
|
*
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define ARG0 a0
|
|||
|
|
#define ARG1 a1
|
|||
|
|
#define ARG2 a2
|
|||
|
|
#define ARG3 a3
|
|||
|
|
#define ARG4 a4
|
|||
|
|
#define ARG5 a5
|
|||
|
|
#define ARG6 a6
|
|||
|
|
#define ARG7 a7
|
|||
|
|
#define ARG8 a8
|
|||
|
|
#define ARG9 a9
|
|||
|
|
|
|||
|
|
#define ARGS_TYPE long
|
|||
|
|
#define ARGS_LIST ARG0,ARG1,ARG2,ARG3,ARG4,ARG5,ARG6,ARG7,ARG8,ARG9
|
|||
|
|
#define ARGS_DCL auto ARGS_TYPE ARGS_LIST
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* A pointer of type "va_list" points to a section of memory
|
|||
|
|
* containing an array of variable sized arguments of unknown
|
|||
|
|
* number. This pointer is initialized by the va_start
|
|||
|
|
* macro to point to the first byte of the first argument.
|
|||
|
|
* We can then use it to walk through the argument list by
|
|||
|
|
* incrementing it by the size of the argument being referenced.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
typedef char *va_list;
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* The first variable argument overlays va_alist, which is
|
|||
|
|
* nothing more than a "handle" which allows us to get the
|
|||
|
|
* address of the first argument on the stack. Note that
|
|||
|
|
* by definition, the va_dcl macro includes the terminating
|
|||
|
|
* semicolon, which makes use of va_dcl in the source code
|
|||
|
|
* appear to be missing a semicolon.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define va_dcl ARGS_TYPE va_alist;
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* The va_start macro takes a variable of type "va_list" and
|
|||
|
|
* initializes it. In our case, it initializes a local variable
|
|||
|
|
* of type "pointer to char" to point to the first argument on
|
|||
|
|
* the stack.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define va_start(list) list = (char *) &va_alist
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* The va_end macro is a null operation for our use.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define va_end(list)
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* The va_arg macro is the tricky one. This one takes
|
|||
|
|
* a va_list as the first argument, and a type as the second
|
|||
|
|
* argument, and returns a value of the appropriate type
|
|||
|
|
* while advancing the va_list to the following argument.
|
|||
|
|
* For our case, we first increment the va_list arg by the
|
|||
|
|
* size of the type being recovered, cast the result to
|
|||
|
|
* a pointer of the appropriate type, and then dereference
|
|||
|
|
* that pointer as an array to get the previous arg (which
|
|||
|
|
* is the one we wanted.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
#define va_arg(list,type) ((type *) (list += sizeof (type)))[-1]
|