mes/module/mes/libc.mes

;;; -*-scheme-*-

;;; Mes --- Maxwell Equations of Software
;;; Copyright © 2016,2017 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; This file is part of Mes.
;;;
;;; Mes is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; Mes is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Mes.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; libc.mes provides a minimal portable C library for mescc.

;;; Code:

(cond-expand
 (guile-2)
 (guile)
 (mes
  (mes-use-module (nyacc lang c99 parser))
  (mes-use-module (mes libc-i386))))

(define _start
  (let* ((argc-argv (i386:_start))
         (ast (with-input-from-string
                  (string-append "int _start () {int i;asm(\"" argc-argv "\");i=main ();exit (i);}")
                parse-c99)))
    ast))

(define strlen
  (let* ((ast (with-input-from-string
                  "
int
strlen (char const* s)
{
  int i = 0;
  while (s[i]) i++;
  return i;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define getchar
  (let* ((ast (with-input-from-string
                  "
int g_stdin;
int
getchar ()
{
  char c;
  int r = read (g_stdin, &c, 1);
  //int r = read (0, &c, 1);
  if (r < 1) return -1;
  return c;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define putchar
  (let* ((ast (with-input-from-string
                  "
int
putchar (int c)
{
  //write (STDOUT, s, strlen (s));
  //int i = write (STDOUT, s, strlen (s));
  write (1, (char*)&c, 1);
  return 0;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define eputs
  (let* ((ast (with-input-from-string
                  "
int
eputs (char const* s)
{
  //write (STDERR, s, strlen (s));
  //write (2, s, strlen (s));
  int i = strlen (s);
  write (2, s, i);
  return 0;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define fputs
  (let* ((ast (with-input-from-string
                  "
int
fputs (char const* s, int fd)
{
  int i = strlen (s);
  write (fd, s, i);
  return 0;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define puts
  (let* ((ast (with-input-from-string
                  "
int
puts (char const* s)
{
  //write (STDOUT, s, strlen (s));
  //int i = write (STDOUT, s, strlen (s));
  int i = strlen (s);
  write (1, s, i);
  return 0;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define strcmp
  (let* ((ast (with-input-from-string
                  "
int
strcmp (char const* a, char const* b)
{
  while (*a && *b && *a == *b) 
    {
      a++;b++;
    }
  return *a - *b;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define itoa
  (let* ((ast (with-input-from-string
                  "
char itoa_buf[10];

char const*
itoa (int x)
{
  //static char itoa_buf[10];
  //char *p = buf+9;
  char *p = itoa_buf;
  p += 9;
  *p-- = 0;

  //int sign = x < 0;
  int sign;
  sign = x < 0;
  if (sign)
    x = -x;
  
  do
    {
      *p-- = '0' + (x % 10);
      x = x / 10;
    } while (x);

  if (sign)
    *p-- = '-';

  return p+1;
}
"
;;paredit:"
                parse-c99)))
    ast))

;;;;

(define assert_fail
  (let* ((ast (with-input-from-string
                  "
void
assert_fail (char* s)
{
  eputs (\"assert fail: \");
  eputs (s);
  eputs (\"\n\");
  //*((int*)0) = 0;
  char *fail = s;
  fail = 0;
  *fail = 0;
}
"
;;paredit:"
                parse-c99)))
    ast))

(define libc
  (list
   strlen
   getchar
   putchar
   eputs
   fputs
   puts
   strcmp
   itoa
   assert_fail))