home *** CD-ROM | disk | FTP | other *** search
- /* genarch.c */
- /* Generate a header file (arch.h) with parameters */
- /* reflecting the machine architecture and compiler characteristics. */
-
- #include <stdio.h>
-
- /* We should write the result on stdout, but the Turbo C 'make' */
- /* can't handle output redirection (sigh). */
-
- main(argc, argv)
- int argc;
- char *argv[];
- { char *fname = argv[1];
- long one = 1;
- struct { char c; short s; } ss;
- struct { char c; long l; } sl;
- struct { char c; float f; } sf;
- struct { char c; double d; } sd;
- long lm1 = -1;
- long lr1 = lm1 >> 1, lr2 = lm1 >> 2;
- unsigned long um1 = ~(unsigned long)0;
- int im1 = -1;
- int ir1 = im1 >> 1, ir2 = im1 >> 2;
- int ars;
- int lwidth = sizeof(long) * 8;
- float f0 = 0.0, f1 = 1.0, fm1 = -1.0;
- FILE *f = fopen(fname, "w");
- if ( f == NULL )
- { fprintf(stderr, "genarch.c: can't open %s for writing\n", fname);
- exit(1);
- }
- fprintf(f, "/* Parameters derived from machine and compiler architecture */\n\n");
- fprintf(f, "#define arch_is_big_endian %d\n", 1 - *(char *)&one);
- fprintf(f, "#define arch_align_short_mod %d\n",
- (char *)&ss.s - &ss.c);
- fprintf(f, "#define arch_align_long_mod %d\n",
- (char *)&sl.l - &sl.c);
- fprintf(f, "#define arch_align_float_mod %d\n",
- (char *)&sf.f - &sf.c);
- fprintf(f, "#define arch_align_double_mod %d\n",
- (char *)&sd.d - &sd.c);
- fprintf(f, "#define arch_sizeof_short %d\n", sizeof(short));
- fprintf(f, "#define arch_sizeof_int %d\n", sizeof(int));
- fprintf(f, "#define arch_sizeof_long %d\n", sizeof(long));
- fprintf(f, "#define arch_floats_are_IEEE %d\n",
- (*(long *)&f0 == 0 && *(long *)&f1 == 0x3f800000L &&
- *(long *)&fm1 == 0xbf800000L ? 1 : 0));
- /* There are three cases for arithmetic right shift: */
- /* always correct, correct except for right-shifting a long by 1 */
- /* (a bug in some versions of the Turbo C compiler), and */
- /* never correct. */
- ars = (lr2 != -1 || ir1 != -1 || ir2 != -1 ? 0 :
- lr1 != -1 ? 1 : /* Turbo C problem */
- 2);
- fprintf(f, "#define arch_arith_rshift %d\n", ars);
- /* Some machines can't handle a variable shift by */
- /* the full width of a long. */
- fprintf(f, "#define arch_can_shift_full_long %d\n",
- um1 >> lwidth == 0);
- fclose(f);
- return 0;
- }
-