#include <sys/types.h>
#include <sys/syscall.h>

#include <stdio.h>

struct syscall {
  char *name;
  int   vec;
} syscalls[] = {
#define SYSTEM_CALL(func,vec) { #func, vec},
#include <sys/syscall.def>
#undef SYSTEM_CALL
};

int nsyscall = sizeof(syscalls) / sizeof (syscalls[0]);

#define IXEMULBASE "_ixemulbase"
#define IXEMULBASELEN 11

#define BASEREL_OFFSET1 19
#define BASEREL_OFFSET2 31

/* The following code is a hexdump of this assembly program:

		.globl	_FUNCTION
_FUNCTION:	movel	a4@(_ixemulbase:W),a0
		jmp	a0@(OFFSET:w)
*/

static short baserel_code[] = {
  0x0000, 0x0107, 0x0000, 0x0008, 0x0000, 0x0000, 0x0000, 0x0000,
  0x0000, 0x0018, 0x0000, 0x0000, 0x0000, 0x0008, 0x0000, 0x0000,
  0x206c, 0x0000, 0x4ee8, 0xff46, 0x0000, 0x0002, 0x0000, 0x0138,
  0x0000, 0x0004, 0x0500, 0x0000, 0x0000, 0x0000, 0x0000, 0x0011,
  0x0100, 0x0000, 0x0000, 0x0000
};

#define NO_BASEREL_OFFSET1 20
#define NO_BASEREL_OFFSET2 33

/* The following code is a hexdump of this assembly program:

		.globl	_FUNCTION
_FUNCTION:	movel	_ixemulbase,a0
		jmp	a0@(OFFSET:w)
*/

static short no_baserel_code[] = {
  0x0000, 0x0107, 0x0000, 0x000c, 0x0000, 0x0000, 0x0000, 0x0000,
  0x0000, 0x0018, 0x0000, 0x0000, 0x0000, 0x0008, 0x0000, 0x0000,
  0x2079, 0x0000, 0x0000, 0x4ee8, 0xffe2, 0x0000, 0x0000, 0x0002,
  0x0000, 0x0150, 0x0000, 0x0004, 0x0500, 0x0000, 0x0000, 0x0000,
  0x0000, 0x000b, 0x0100, 0x0000, 0x0000, 0x0000
};

#define PROFILING_OFFSET1 29
#define PROFILING_OFFSET2 51
#define PROFILING_OFFSET3 57
#define PROFILING_OFFSET4 63

/* The following code is a hexdump of this assembly program:

		.globl	_FUNCTION
_FUNCTION:
		.data
PROFFUNCTION:
		.long	0

		.text
		link	a5,#0
		lea	PROFFUNCTION,a0
		jsr	mcount
		unlk	a5
		movel	_ixemulbase,a0
		jmp	a0@(OFFSET:w)
*/

static short profiling_code[] = {
  0x0000, 0x0107, 0x0000, 0x001c, 0x0000, 0x0004, 0x0000, 0x0000,
  0x0000, 0x0030, 0x0000, 0x0000, 0x0000, 0x0018, 0x0000, 0x0000,
  0x4e55, 0x0000, 0x41f9, 0x0000, 0x001c, 0x4eb9, 0x0000, 0x0000,
  0x4e5d, 0x2079, 0x0000, 0x0000, 0x4ee8, 0xffe2, 0x0000, 0x0000,
  0x0000, 0x0006, 0x0000, 0x0640, 0x0000, 0x000c, 0x0000, 0x0250,
  0x0000, 0x0014, 0x0000, 0x0350, 0x0000, 0x0004, 0x0500, 0x0000,
  0x0000, 0x0000, 0x0000, 0x000b, 0x0600, 0x0000, 0x0000, 0x001c,
  0x0000, 0x0015, 0x0100, 0x0000, 0x0000, 0x0000, 0x0000, 0x001c,
  0x0100, 0x0000, 0x0000, 0x0000
};

void usage(void)
{
  fprintf(stderr, "Usage: gen_glue baserel | no-baserel | profiling\n");
  exit(1);
}

void write_code(short *code, int len, FILE *f)
{
  const short endian = 0x0100;

  /* test if gen_glue is compiled on a big or little endian machine */
  if (((char *)&endian)[0])
  {
    fwrite(code, len, 1, f);		/* big endian */
  }
  else
  {
    int i;

    for (i = 0; i < len / 2; i++)
    {
      short x = code[i];		/* little endian */
      
      fputc(((char *)&x)[1], f);
      fputc(((char *)&x)[0], f);
    }
  }
}

int main(int argc, char **argv)
{
  FILE *fp;
  struct syscall *sc;
  int i, v, baserel = 0, profiling = 0;
  short *code;
  int offset1, offset2, size;
  int zero = 0;

  if (argc != 2)
    usage();
  if (!strcmp(argv[1], "baserel"))
    {
      baserel = 1; profiling = 0;
    }
  else if (!strcmp(argv[1], "no-baserel"))
    {
      baserel = 0; profiling = 0;
    }
  else if (!strcmp(argv[1], "profiling"))
    {
      baserel = 0; profiling = 1;
    }
  else usage();
  
  for (i = 0, sc = syscalls; i < nsyscall; i++, sc++)
    {
      int namelen = strlen(sc->name);
      char name[namelen + 3];

      if (!memcmp(sc->name, "__obsolete", 10))
        continue;
      if (!memcmp(sc->name, "__must_recompile", 16))
        continue;
      if (!memcmp(sc->name, "__stk", 5))
        continue;
      v = -(sc->vec + 4) * 6;
      sprintf (name, "%s.o", sc->name);

      fp = fopen (name, "w");
      
      if (!fp)
        {
          perror (sc->name);
          exit (20);
        }

      code = no_baserel_code;
      size = sizeof(no_baserel_code);
      offset1 = NO_BASEREL_OFFSET1;
      offset2 = NO_BASEREL_OFFSET2;
      if (profiling)
        {
          profiling_code[PROFILING_OFFSET1] = v;
          profiling_code[PROFILING_OFFSET2] = 6 + namelen;
          profiling_code[PROFILING_OFFSET3] = 6 + namelen * 2 + 5;
          profiling_code[PROFILING_OFFSET4] = 6 + namelen * 2 + 5 + 7;
          write_code(profiling_code, sizeof(profiling_code), fp);
          fwrite(&zero, 3, 1, fp);
          fputc((char)(namelen * 2 + 7 + IXEMULBASELEN + 1 + 7 + 4), fp);
          fputc('_', fp);
          fwrite(sc->name, namelen + 1, 1, fp);
          fprintf(fp, "PROF");
          fwrite(sc->name, namelen + 1, 1, fp);
          fwrite("mcount", 7, 1, fp);
        }
      else
	{
	  if (baserel && sc->vec != SYS_ix_geta4)
	    {
              code = baserel_code;
              size = sizeof(baserel_code);
              offset1 = BASEREL_OFFSET1;
              offset2 = BASEREL_OFFSET2;
            }
          code[offset1] = v;
          code[offset2] = namelen + 4 + 2;
          write_code(code, size, fp);
          fwrite(&zero, 3, 1, fp);
          fputc((char)(namelen + 2 + IXEMULBASELEN + 1 + 4), fp);
          fputc('_', fp);
          fwrite(sc->name, namelen + 1, 1, fp);
        }
      fwrite(IXEMULBASE, IXEMULBASELEN + 1, 1, fp);
      fclose (fp);
    }
  return (0);
}