1 (* varargs.mod provides a basic vararg facility for GNU Modula-2.
3 Copyright (C) 2015-2022 Free Software Foundation, Inc.
4 Contributed by Gaius Mulley <gaius@glam.ac.uk>.
6 This file is part of GNU Modula-2.
8 GNU Modula-2 is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GNU Modula-2 is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Modula-2; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. *)
22 IMPLEMENTATION MODULE varargs ;
24 FROM Storage IMPORT ALLOCATE, DEALLOCATE ;
25 FROM libc IMPORT memcpy ;
26 FROM SYSTEM IMPORT ADDRESS, TSIZE, ADR, BYTE ;
33 vararg = POINTER TO RECORD
38 arg : ARRAY [0..MaxArg] OF argDesc ;
46 ptrToByte = POINTER TO BYTE ;
50 arg - fills in, a, with the next argument. The size of, a, must be an exact
51 match with the original vararg parameter.
54 PROCEDURE arg (v: vararg; VAR a: ARRAY OF BYTE) ;
62 HALT (* too many calls to arg. *)
64 IF HIGH(a)+1=arg[i].len
74 HALT (* parameter mismatch. *)
83 nargs - returns the number of arguments wrapped in, v.
86 PROCEDURE nargs (v: vararg) : CARDINAL ;
93 copy - returns a copy of, v.
96 PROCEDURE copy (v: vararg) : vararg ;
107 ALLOCATE (contents, size) ;
108 contents := memcpy (contents, v^.contents, size) ;
109 FOR j := 0 TO nArgs DO
110 offset := VAL (CARDINAL, VAL (ptrToByte, v^.contents) - VAL (ptrToByte, v^.arg[j].ptr)) ;
111 arg[j].ptr := VAL (ptrToByte, VAL (ptrToByte, contents) + offset) ;
112 arg[j].len := v^.arg[j].len ;
120 replace - fills the next argument with, a. The size of, a,
121 must be an exact match with the original vararg
125 PROCEDURE replace (v: vararg; VAR a: ARRAY OF BYTE) ;
133 HALT (* too many calls to arg. *)
135 IF HIGH(a)+1=arg[i].len
145 HALT (* parameter mismatch. *)
153 next - assigns the next arg to be collected as, i.
156 PROCEDURE next (v: vararg; i: CARDINAL) ;
163 end - destructor for vararg, v.
166 PROCEDURE end (VAR v: vararg) ;
170 DEALLOCATE (v^.contents, TSIZE (vararg)) ;
177 start1 - wraps up argument, a, into a vararg.
180 PROCEDURE start1 (a: ARRAY OF BYTE) : vararg ;
188 size := HIGH (a) + 1;
189 ALLOCATE (contents, size) ;
190 contents := memcpy (contents, ADR (a), size) ;
191 arg[0].ptr := contents ;
199 start2 - wraps up arguments, a, b, into a vararg.
202 PROCEDURE start2 (a, b: ARRAY OF BYTE) : vararg ;
211 size := HIGH (a) + HIGH (b) + 2 ;
212 ALLOCATE (contents, size) ;
213 p := memcpy (contents, ADR (a), HIGH (a) + 1) ;
215 arg[0].len := HIGH (a) + 1 ;
216 INC (p, arg[0].len) ;
217 p := memcpy (p, ADR (b), HIGH (b) + 1) ;
219 arg[1].len := HIGH (b) + 1
226 start3 - wraps up arguments, a, b, c, into a vararg.
229 PROCEDURE start3 (a, b, c: ARRAY OF BYTE) : vararg ;
238 size := HIGH (a) + HIGH (b) + HIGH (c) + 3 ;
239 ALLOCATE (contents, size) ;
240 p := memcpy (contents, ADR (a), HIGH (a) + 1) ;
242 arg[0].len := HIGH (a) + 1 ;
243 INC (p, arg[0].len) ;
244 p := memcpy (p, ADR (b), HIGH (b) + 1) ;
246 arg[1].len := HIGH (b) + 1 ;
247 INC (p, arg[1].len) ;
248 p := memcpy (p, ADR (c), HIGH (c) + 1) ;
250 arg[2].len := HIGH (c) + 1
257 start4 - wraps up arguments, a, b, c, d, into a vararg.
260 PROCEDURE start4 (a, b, c, d: ARRAY OF BYTE) : vararg ;
269 size := HIGH (a) + HIGH (b) + HIGH (c) + HIGH (d) + 4 ;
270 ALLOCATE (contents, size) ;
271 p := memcpy (contents, ADR (a), HIGH (a) + 1) ;
272 arg[0].len := HIGH (a) + 1 ;
273 INC (p, arg[0].len) ;
274 p := memcpy (p, ADR (b), HIGH (b) + 1) ;
276 arg[1].len := HIGH (b) + 1 ;
277 INC (p, arg[1].len) ;
278 p := memcpy (p, ADR (c), HIGH (c) + 1) ;
280 arg[2].len := HIGH (c) + 1 ;
281 INC (p, arg[2].len) ;
282 p := memcpy (p, ADR (c), HIGH (c) + 1) ;
284 arg[3].len := HIGH (c) + 1