mes/scaffold/t.c

/* -*-comment-start: "//";comment-end:""-*-
 * 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/>.
 */

#if __GNUC__
void
exit (int code)
{
  asm (
       "movl %0,%%ebx\n\t"
       "movl $1,%%eax\n\t"
       "int  $0x80"
       : // no outputs "=" (r)
       : "" (code)
       );
  // not reached
  exit (0);
}

void
write (int fd, char const* s, int n)
{
  int r;
  //syscall (SYS_write, fd, s, n));
  asm (
       "mov %0,%%ebx\n\t"
       "mov %1,%%ecx\n\t"
       "mov %2,%%edx\n\t"

       "mov $0x4,%%eax\n\t"
       "int $0x80\n\t"
       : // no outputs "=" (r)
       : "" (fd), "" (s), "" (n)
       : "eax", "ebx", "ecx", "edx"
       );
}

#define STDOUT 1

typedef long size_t;
size_t
strlen (char const* s)
{
  int i = 0;
  while (s[i]) i++;
  return i;
}

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;
}

int
putchar (int c)
{
  //write (STDOUT, s, strlen (s));
  //int i = write (STDOUT, s, strlen (s));
  write (1, (char*)&c, 1);
  return 0;
}

int
strcmp (char const* a, char const* b)
{
  while (*a && *b && *a == *b) {a++;b++;}
  return *a - *b;
}
int test (char *p);
#endif

// struct scm {
//   int type;
//   int car;
//   int cdr;
// };

char arena[20];
char *g_cells = arena;

int
main (int argc, char *argv[])
{
  char *p = "t.c\n";
  puts ("t.c\n");

  if (argc > 1 && !strcmp (argv[1], "--help")) return 1;
  puts ("t: if (argc > 1 && !strcmp (argv[1], \"--help\")\n");

  // FIXME mescc?!
  if (argc > 1) if (!strcmp (argv[1], "--help")) return 1;

  return test (p);
  return 22;
}

int
swits (int c)
{
  int x = -1;
  switch (c)
    {
      case 0:
        {
          x = 0;
          c = 34;
          break;
        }
      case 1:
        {
          x = 1;
          break;
        }
      default:
        {
          x = 2;
          break;
        }
    }
  return x;
}

int
test (char *p)
{
  int f = 0;
  int t = 1;
  int one = 1;

  puts ("t: if (0)\n");
  if (0) return 1;

  puts ("t: if (f)\n");
  if (f) return 1;

  puts ("t: if (one > 1)\n");
  if (one > 1) return 1;

  puts ("t: if (one < 0)\n");
  if (one < 0) return 1;

  puts ("t: if (strlen (\"\"))\n");
  if (strlen ("")) return 1;

  puts ("t: if (strlen (p) != 4)\n");
  if (strlen (p) != 4) return 1;

  puts ("t: if (!strlen (\".\"))\n");
  if (!strlen (".")) return 1;

  puts ("t: if (strcmp (p, \"foo\"))\n");
  if (!strcmp (p, "foo")) return 1;

  puts ("t: if (strcmp (p, \"t.c\\n\"))\n");
  if (strcmp (p, "t.c\n")) return 1;

  puts ("t: if (!1)\n");
  if (!1) return 1;

  puts ("t: if (one == 0)\n");
  if (one == 0) return 1;

  puts ("t: if (f != 0)\n");
  if (one != 1) return 1;

  puts ("t: if (1 && 0)\n");
  if (1 && 0) return 1;

  puts ("t: if (!t && f)\n");
  if (!t && f) return 1;

  puts ("t: if (t && !one)\n");
  if (t && !one) return 1;

  int i=0;
  puts ("t: if (i++)\n");
  if (i++) return 1;

  puts ("t: if (--i)\n");
  if (--i) return 1;

  puts ("t: (one == 1) ?\n");
  (one == 1) ? 1 : exit (1);

  puts ("t: (f) ?\n");
  (f) ? exit (1) : 1;

  puts ("t: *x != 'Q'\n");
  g_cells[0] = 'Q';
  char *x = g_cells;
  if (*x != 'Q') return 1;

  puts ("t: switch 0\n");
  if (swits (0) != 0) return swits (0);

  puts ("t: switch 1\n");
  if (swits (1) != 1) return 1;

  puts ("t: switch -1\n");
  if (swits (-1) != 2) return 1;

  puts ("t: if (1)\n");
  if (1) goto ok0;
  return 1;
 ok0:
  
  puts ("t: if (t)\n");
  if (t) goto ok1;
  return 1;
 ok1:

  puts ("t: if (one > 0)\n");
  if (one > 0) goto ok2;
  return 1;
 ok2:

  puts ("t: if (one < 2)\n");
  if (one < 2) goto ok3;
  return 1;
 ok3:

  puts ("t: if (strlen (\".\"))\n");
  if (strlen (".")) goto ok4;
  return 1;
 ok4:

  puts ("t: if (strlen (p) == 4)\n");
  if (strlen (p) == 4) goto ok40;
 ok40:

  puts ("t: if (!strcmp (p, \"t.c\\n\"))\n");
  if (!strcmp (p, "t.c\n")) goto ok41;
  return 1;
 ok41:

  puts ("t: if (strcmp (p, \"foo\"))\n");
  if (strcmp (p, "foo")) goto ok42;
  return 1;
 ok42:

  puts ("t: if (!0)\n");
  if (!0) goto ok5;
  return 1;
 ok5:

  puts ("t: if (one == 1)\n");
  if (one == 1) goto ok6;
  return 1;
 ok6:

  puts ("t: if (one != 0)\n");
  if (one != 0) goto ok7;
  return 1;
 ok7:

  puts ("t: if (1 && !0)\n");
  if (1 && !0) goto ok8;
  return 1;
 ok8:

  puts ("t: if (++i)\n");
  if (++i) goto ok9;
 ok9:

  puts ("t: if (i--)\n");
  if (i--) goto ok10;
 ok10:

  puts ("t: for (i=0; i<4; ++i)\n");
  for (i=0; i<4; ++i);
  if (i != 4) return i;

  return 0;
}

#if __GNUC__
void
_start ()
{
  // int r=main ();
  // exit (r);
  int r;
  asm (
       "mov %%ebp,%%eax\n\t"
       "addl $8,%%eax\n\t"
       "push %%eax\n\t"

       "mov %%ebp,%%eax\n\t"
       "addl $4,%%eax\n\t"
       "movzbl (%%eax),%%eax\n\t"
       "push %%eax\n\t"

       "call main\n\t"
       
       "movl %%eax,%0\n\t"
       : "=r" (r)
       : //no inputs "" (&main)
       );
  exit (r);
}
#endif