mdw@git.distorted.org.uk Git - xchg-rax-rax/blob - main.c

   1 #include <ctype.h>
   2 #include <errno.h>
   3 #include <limits.h>
   4 #include <stdarg.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8
   9 union reg {
  10   unsigned char *p;
  11   long i;
  12   long u;
  13 };
  14
  15 #if defined(__i386__)
  16 #  define GPREGS(_)                                                     \
  17         _(a) _(b) _(c) _(d) _(si) _(di) _(bp)
  18 #elif defined(__x86_64__)
  19 #  define GPREGS(_)                                                     \
  20         _(a) _(b) _(c) _(d) _(si) _(di) _(bp)                           \
  21         _(r8) _(r9) _(r10) _(r11) _(r12) _(r13) _(r14) _(r15)
  22 #elif defined(__arm__)
  23 #  define GPREGS(_)                                                     \
  24         _(r0) _(r1) _(r2) _(r3) _(r4) _(r5) _(r6) _(r7)                 \
  25         _(r8) _(r9) _(r10) _(r11) _(r12)
  26 #elif defined(__aarch64__)
  27 #  define GPREGS(_)                                                     \
  28         _(x0) _(x1) _(x2) _(x3) _(x4) _(x5) _(x6) _(x7)                 \
  29         _(x8) _(x9) _(x10) _(x11) _(x12) _(x13) _(x14) _(x15)
  30 #else
  31 #  error "not supported"
  32 #endif
  33
  34 enum {
  35 #define DEFCONST(r) R_##r,
  36   GPREGS(DEFCONST)
  37 #undef DEFCONST
  38   R_flags,
  39   NREGS
  40 };
  41
  42 static const char *const rname[] = {
  43 #define DEFNAME(r) #r,
  44   GPREGS(DEFNAME)
  45 #undef DEFNAME
  46   "f"
  47 };
  48
  49 struct regs {
  50   union reg r[NREGS];
  51 };
  52
  53 struct seg {
  54   unsigned char *p;
  55   size_t sz;
  56 };
  57
  58 #define N(v) (sizeof(v)/sizeof((v)[0]))
  59
  60 #define STRCMP(a, op, b) (strcmp((a), (b)) op 0)
  61 #define STRNCMP(a, op, b, n) (strncmp((a), (b), (n)) op 0)
  62 #define CTYPE_HACK(func, ch) func((unsigned char)(ch))
  63 #define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
  64 #define ISSPACE(ch) CTYPE_HACK(isspace, ch)
  65
  66 #define XCHG(_)                                                         \
  67   _(x00) _(x01) _(x02) _(x03) _(x04) _(x05) _(x06) _(x07)               \
  68   _(x08) _(x09) _(x0a) _(x0b) _(x0c) _(x0d) _(x0e) _(x0f)               \
  69   _(x10) _(x11) _(x12) _(x13) _(x14) _(x15) _(x16) _(x17)               \
  70   _(x18) _(x19) _(x1a) _(x1b) _(x1c) _(x1d) _(x1e) _(x1f)               \
  71   _(x20) _(x21) _(x22) _(x23) _(x24) _(x25) _(x26) _(x27)               \
  72   _(x28) _(x29) _(x2a) _(x2b) _(x2c) _(x2d) _(x2e) _(x2f)               \
  73   _(x30) _(x31) _(x32) _(x33) _(x34) _(x35) _(x36) _(x37)               \
  74   _(x38) _(x39) _(x3a) _(x3b) _(x3c) _(x3d) _(x3e) _(x3f)
  75
  76 #define DECL(x) extern const int x;
  77 XCHG(DECL)
  78 extern const int nop;
  79
  80 static const int *x[] = {
  81 #define SLOT(x) &x,
  82   XCHG(SLOT)
  83 };
  84
  85 extern void call_example(const int *f, struct regs *r);
  86
  87 static const char *prog = "???";
  88
  89 __attribute__((format(printf, 1, 2), noreturn))
  90 static void barf(const char *m, ...)
  91 {
  92   va_list ap;
  93
  94   va_start(ap, m);
  95   fprintf(stderr, "%s: ", prog);
  96   vfprintf(stderr, m, ap);
  97   putc('\n', stderr);
  98   va_end(ap);
  99   exit(127);
 100 }
 101
 102 static void *xmalloc(size_t sz)
 103 {
 104   void *p;
 105
 106   if (!sz) return (0);
 107   p = malloc(sz);
 108   if (!p) barf("malloc failed");
 109   return (p);
 110 }
 111
 112 #define DEF_PARSEINT(name, ty, strto)                                   \
 113   static ty parse_##name(const char *what, const char *p, ty min, ty max) \
 114   {                                                                     \
 115     const char *pp = p;                                                 \
 116     char *q;                                                            \
 117     ty i;                                                               \
 118     int err;                                                            \
 119                                                                         \
 120     if (ISSPACE(*p)) goto bad;                                          \
 121     err = errno; errno = 0;                                             \
 122     i = strto(p, &q, 0);                                                \
 123     if (errno) goto bad;                                                \
 124     if (*q) goto bad;                                                   \
 125     if (i < min || i > max) goto bad;                                   \
 126     errno = err;                                                        \
 127     return (i);                                                         \
 128                                                                         \
 129   bad:                                                                  \
 130     barf("bad %s `%s'", what, pp);                                      \
 131   }
 132 DEF_PARSEINT(long, long, strtol)
 133 DEF_PARSEINT(ulong, unsigned long, strtoul)
 134
 135 static int hex_digit(char ch)
 136 {
 137   if ('0' <= ch && ch <= '9') return (ch - '0');
 138   else if ('A' <= ch && ch <= 'F') return (ch - 'A' + 10);
 139   else if ('a' <= ch && ch <= 'f') return (ch - 'a' + 10);
 140   else return (-1);
 141 }
 142
 143 static void setreg(union reg *r, struct seg **seg_inout, const char *p)
 144 {
 145   struct seg *seg;
 146   const char *pp;
 147   unsigned char *q;
 148   int hi, lo;
 149   size_t n;
 150
 151 #define LONG_REG(p) (parse_long("signed register", (p), LONG_MIN, LONG_MAX))
 152 #define ULONG_REG(p) (parse_ulong("unsigned register", (p), 0, ULONG_MAX))
 153
 154   switch (*p) {
 155     case '-':
 156       if (p[1]) r->i = LONG_REG(p);
 157       break;
 158     case 'i':
 159       if (p[1] != ':') goto bad;
 160       r->i = LONG_REG(p + 2);
 161       break;
 162     case 'u':
 163       if (p[1] != ':') goto bad;
 164       r->u = ULONG_REG(p + 2);
 165       break;
 166     case 'c':
 167       if (p[1] != ':' || p[3]) goto bad;
 168       r->u = p[2];
 169       break;
 170     case 's':
 171       if (p[1] != ':') goto bad;
 172       pp = p + 2; n = strlen(pp) + 1;
 173       seg = (*seg_inout)++; seg->p = xmalloc(n); seg->sz = n;
 174       memcpy(seg->p, pp, n); r->p = seg->p;
 175       break;
 176     case 'm':
 177       if (p[1] != ':') goto bad;
 178       pp = p + 2; n = strlen(pp); if (n%2) goto bad;
 179       seg = (*seg_inout)++; seg->p = q = xmalloc(n/2); seg->sz = n/2;
 180       while (n) {
 181         hi = hex_digit(pp[0]); lo = hex_digit(pp[1]);
 182         if (hi < 0 || lo < 0) goto bad;
 183         *q++ = 16*hi + lo; n -= 2; pp += 2;
 184       }
 185       r->p = seg->p;
 186       break;
 187     case 'z':
 188       if (p[1] != ':') goto bad;
 189       n = parse_ulong("buffer length", p + 2, 0, ~(size_t)0);
 190       seg = (*seg_inout)++; seg->p = q = xmalloc(n); seg->sz = n;
 191       r->p = q; memset(q, 0, n);
 192       break;
 193     default:
 194       if (ISDIGIT(*p)) r->u = ULONG_REG(p);
 195       else if (*p == '+') r->i = LONG_REG(p);
 196       else if (*p == '\'' && p[2] == '\'' && !p[3]) r->u = p[1];
 197       else goto bad;
 198       break;
 199     bad:
 200       barf("bad regspec `%s'", p);
 201   }
 202
 203 #undef LONG_REG
 204 #undef ULONG_REG
 205 }
 206
 207 static void dumpreg(const char *name, const union reg *r,
 208                     const struct seg *seg, size_t nseg)
 209 {
 210   size_t i;
 211
 212 #if ULONG_MAX == 0xffffffff
 213   printf("%3s =         0x%08lx = %20ld = %20lu", name, r->u, r->i, r->u);
 214 #else
 215   printf("%3s = 0x%016lx = %20ld = %20lu", name, r->u, r->i, r->u);
 216 #endif
 217   if (r->u >= ' ' && r->u <= '~') printf(" = '%c'", (int)r->u);
 218   for (i = 0; i < nseg; i++) {
 219     if (r->p == seg[i].p)
 220       printf(" = seg[%zu] base", i);
 221     else if (r->p == seg[i].p + seg[i].sz)
 222       printf(" = seg[%zu] limit", i);
 223     else if (seg[i].p < r->p && r->p < seg[i].p + seg[i].sz)
 224       printf(" = seg[%zu] + %zu", i, (size_t)(r->p - seg[i].p));
 225   }
 226   putchar('\n');
 227 }
 228
 229 static void dumpseg(const struct seg *seg)
 230 {
 231   size_t i, j;
 232   unsigned char ch;
 233
 234   for (i = 0; i < seg->sz; i += 8) {
 235     printf("\t%8zx :", i);
 236     for (j = 0; j < 8; j++)
 237       if (i + j >= seg->sz) printf(" **");
 238       else printf(" %02x", seg->p[i + j]);
 239     printf(" : ");
 240     for (j = 0; j < 8; j++)
 241       if (i + j >= seg->sz) putchar('*');
 242       else {
 243         ch = seg->p[i + j];
 244         if (' ' <= ch && ch <= '~') putchar(ch);
 245         else putchar('.');
 246       }
 247     putchar('\n');
 248   }
 249 }
 250
 251 int main(int argc, char *argv[])
 252 {
 253   struct regs r;
 254   struct seg seg[16], *segp = seg;
 255   size_t nseg, n;
 256   const char *p;
 257   char *q;
 258   unsigned long f;
 259   int i, j, k;
 260   unsigned long l;
 261
 262   prog = strrchr(argv[0], '/'); if (prog) prog++; else prog = argv[0];
 263
 264   if (argc < 2)
 265     barf("usage: %s I [REG...]",
 266          prog);
 267
 268   j = parse_long("program index", argv[1], -1, N(x) - 1);
 269
 270 #if ULONG_MAX == 0xffffffff
 271 #  define DEAD 0xdeadbeef
 272 #else
 273 #  define DEAD 0xdeadbeefdeadbeef
 274 #endif
 275   for (i = 0; i < NREGS - 1; i++) r.r[i].u = DEAD;
 276 #undef DEAD
 277   r.r[R_flags].u = 0;
 278
 279   i = 0;
 280   argv += 2;
 281   while (*argv) {
 282     p = *argv++;
 283     if (ISDIGIT(*p)) {
 284       l = strtoul(p, &q, 10);
 285       if (l < NREGS && *q == '=') { p = q + 1; i = l; }
 286     } else for (k = 0; k < NREGS; k++) {
 287       n = strlen(rname[k]);
 288       if (STRNCMP(p, ==, rname[k], n) && p[n] == '=')
 289         { i = k; p += n + 1; break; }
 290     }
 291     if (i >= NREGS) barf("too many registers");
 292     setreg(&r.r[i], &segp, p); i++;
 293   }
 294
 295   nseg = segp - seg;
 296   call_example(j < 0 ? &nop : x[j], &r);
 297
 298   for (i = 0; i < NREGS; i++) dumpreg(rname[i], &r.r[i], seg, nseg);
 299
 300   f = r.r[R_flags].u;
 301
 302 #if defined(__i386__) || defined(__x86_64__)
 303
 304 #define CF (1 <<  0)
 305 #define PF (1 <<  2)
 306 #define ZF (1 <<  6)
 307 #define SF (1 <<  7)
 308 #define OF (1 << 11)
 309
 310   printf("\tstatus: %ccf %cpf %caf %czf %csf %cdf %cof\n",
 311          (f >>  0)&1u ? '+' : '-',
 312          (f >>  2)&1u ? '+' : '-',
 313          (f >>  4)&1u ? '+' : '-',
 314          (f >>  6)&1u ? '+' : '-',
 315          (f >>  7)&1u ? '+' : '-',
 316          (f >> 10)&1u ? '+' : '-',
 317          (f >> 11)&1u ? '+' : '-');
 318   printf("\tcond:");
 319   if (f&CF) printf(" c/b/nae"); else printf(" nc/ae/nb");
 320   if (f&ZF) printf(" e/z"); else printf(" ne/nz");
 321   if (f&SF) printf(" s"); else printf(" ns");
 322   if (f&OF) printf(" o"); else printf(" no");
 323   if (f&PF) printf(" p"); else printf(" np");
 324   if ((f&CF) || (f&ZF)) printf(" be/na"); else printf(" a/nbe");
 325   if (!(f&OF) == !(f&SF)) printf(" ge/nl"); else printf(" l/nge");
 326   if (!(f&OF) == !(f&SF) && !(f&ZF))
 327     printf(" g/nle"); else printf(" le/ng");
 328   putchar('\n');
 329   printf("\tsystem: %ctf %cif iopl=%d %cnt "
 330                         "%crf %cvm %cac %cvif %cvip %cid\n",
 331          (f >>  8)&1u ? '+' : '-',
 332          (f >>  9)&1u ? '+' : '-',
 333          (int)((f >> 12)&1u),
 334          (f >> 14)&1u ? '+' : '-',
 335          (f >> 16)&1u ? '+' : '-',
 336          (f >> 17)&1u ? '+' : '-',
 337          (f >> 18)&1u ? '+' : '-',
 338          (f >> 19)&1u ? '+' : '-',
 339          (f >> 20)&1u ? '+' : '-',
 340          (f >> 21)&1u ? '+' : '-');
 341
 342 #undef CF
 343 #undef PF
 344 #undef ZF
 345 #undef SF
 346 #undef OF
 347
 348 #elif defined(__arm__)
 349
 350 #define NF (1u << 31)
 351 #define ZF (1u << 30)
 352 #define CF (1u << 29)
 353 #define VF (1u << 28)
 354
 355   {
 356   static const char
 357     *modetab[] = { "?00", "?01", "?02", "?03", "?04", "?05", "?06", "?07",
 358                    "?08", "?09", "?10", "?11", "?12", "?13", "?14", "?15",
 359                    "usr", "fiq", "irq", "svc", "?20", "?21", "mon", "abt",
 360                    "?24", "?25", "hyp", "und", "?28", "?29", "?30", "sys" },
 361     *condtab[] = { "eq", "ne", "cs", "cc", "mi", "pl", "vs", "vc",
 362                    "hi", "ls", "ge", "lt", "gt", "le", "al", "nv" };
 363
 364   printf("\tuser: %cn %cz %cc %cv %cq ge=%c%c%c%c;",
 365          (f >> 31)&1u ? '+' : '-',
 366          (f >> 30)&1u ? '+' : '-',
 367          (f >> 29)&1u ? '+' : '-',
 368          (f >> 28)&1u ? '+' : '-',
 369          (f >> 27)&1u ? '+' : '-',
 370          (f >> 19)&1u ? '1' : '0',
 371          (f >> 18)&1u ? '1' : '0',
 372          (f >> 17)&1u ? '1' : '0',
 373          (f >> 16)&1u ? '1' : '0');
 374   if (f&NF) printf(" mi"); else printf(" pl");
 375   if (f&ZF) printf(" eq"); else printf(" ne");
 376   if (f&CF) printf(" cs/hs"); else printf(" cc/lo");
 377   if (f&VF) printf(" vs"); else printf(" vc");
 378   if ((f&CF) && !(f&ZF)) printf(" hi"); else printf(" ls");
 379   if (!(f&VF) == !(f&NF)) printf(" ge"); else printf(" lt");
 380   if (!(f&VF) == !(f&NF) && !(f&ZF)) printf(" gt"); else printf(" le");
 381   putchar('\n');
 382   printf("\tsystem: %cj it=%s:%c%c%c%c %ce %ca %ci %cf %ct m=%s\n",
 383          (f >> 24)&1u ? '+' : '-',
 384          condtab[(f >> 12)&15u],
 385          (f >> 11)&1u ? '1' : '0',
 386          (f >> 10)&1u ? '1' : '0',
 387          (f >> 26)&1u ? '1' : '0',
 388          (f >> 25)&1u ? '1' : '0',
 389          (f >>  9)&1u ? '+' : '-',
 390          (f >>  8)&1u ? '+' : '-',
 391          (f >>  7)&1u ? '+' : '-',
 392          (f >>  6)&1u ? '+' : '-',
 393          (f >>  5)&1u ? '+' : '-',
 394          modetab[(f >>  0)&31u]);
 395   }
 396
 397 #undef NF
 398 #undef ZF
 399 #undef CF
 400 #undef VF
 401
 402 #elif defined(__aarch64__)
 403
 404 #define NF (1u << 31)
 405 #define ZF (1u << 30)
 406 #define CF (1u << 29)
 407 #define VF (1u << 28)
 408
 409   printf("\tuser: %cn %cz %cc %cv;",
 410          (f >> 31)&1u ? '+' : '-',
 411          (f >> 30)&1u ? '+' : '-',
 412          (f >> 29)&1u ? '+' : '-',
 413          (f >> 28)&1u ? '+' : '-');
 414   if (f&NF) printf(" mi"); else printf(" pl");
 415   if (f&ZF) printf(" eq"); else printf(" ne");
 416   if (f&CF) printf(" cs/hs"); else printf(" cc/lo");
 417   if (f&VF) printf(" vs"); else printf(" vc");
 418   if ((f&CF) && !(f&ZF)) printf(" hi"); else printf(" ls");
 419   if (!(f&VF) == !(f&NF)) printf(" ge"); else printf(" lt");
 420   if (!(f&VF) == !(f&NF) && !(f&ZF)) printf(" gt"); else printf(" le");
 421   putchar('\n');
 422
 423 #undef NF
 424 #undef ZF
 425 #undef CF
 426 #undef VF
 427
 428 #else
 429 #  error "not supported"
 430 #endif
 431
 432   for (i = 0; i < nseg; i++)
 433     { printf("seg[%d] (%p):\n", i, seg[i].p); dumpseg(&seg[i]); }
 434
 435   return (0);
 436 }