src/host/buildvm.c

   1 /*
   2 ** LuaJIT VM builder.
   3 ** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h
   4 **
   5 ** This is a tool to build the hand-tuned assembler code required for
   6 ** LuaJIT's bytecode interpreter. It supports a variety of output formats
   7 ** to feed different toolchains (see usage() below).
   8 **
   9 ** This tool is not particularly optimized because it's only used while
  10 ** _building_ LuaJIT. There's no point in distributing or installing it.
  11 ** Only the object code generated by this tool is linked into LuaJIT.
  12 **
  13 ** Caveat: some memory is not free'd, error handling is lazy.
  14 ** It's a one-shot tool -- any effort fixing this would be wasted.
  15 */
  16
  17 #include "buildvm.h"
  18 #include "lj_obj.h"
  19 #include "lj_gc.h"
  20 #include "lj_bc.h"
  21 #include "lj_ir.h"
  22 #include "lj_ircall.h"
  23 #include "lj_frame.h"
  24 #include "lj_dispatch.h"
  25 #if LJ_HASFFI
  26 #include "lj_ctype.h"
  27 #include "lj_ccall.h"
  28 #endif
  29 #include "luajit.h"
  30
  31 #if defined(_WIN32)
  32 #include <fcntl.h>
  33 #include <io.h>
  34 #endif
  35
  36 /* ------------------------------------------------------------------------ */
  37
  38 /* DynASM glue definitions. */
  39 #define Dst             ctx
  40 #define Dst_DECL        BuildCtx *ctx
  41 #define Dst_REF         (ctx->D)
  42 #define DASM_CHECKS     1
  43
  44 #include "../dynasm/dasm_proto.h"
  45
  46 /* Glue macros for DynASM. */
  47 static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type);
  48
  49 #define DASM_EXTERN(ctx, addr, idx, type) \
  50   collect_reloc(ctx, addr, idx, type)
  51
  52 /* ------------------------------------------------------------------------ */
  53
  54 /* Avoid trouble if cross-compiling for an x86 target. Speed doesn't matter. */
  55 #define DASM_ALIGNED_WRITES     1
  56
  57 /* Embed architecture-specific DynASM encoder. */
  58 #if LJ_TARGET_X86ORX64
  59 #include "../dynasm/dasm_x86.h"
  60 #elif LJ_TARGET_ARM
  61 #include "../dynasm/dasm_arm.h"
  62 #elif LJ_TARGET_PPC
  63 #include "../dynasm/dasm_ppc.h"
  64 #elif LJ_TARGET_PPCSPE
  65 #include "../dynasm/dasm_ppc.h"
  66 #elif LJ_TARGET_MIPS
  67 #include "../dynasm/dasm_mips.h"
  68 #else
  69 #error "No support for this architecture (yet)"
  70 #endif
  71
  72 /* Embed generated architecture-specific backend. */
  73 #include "buildvm_arch.h"
  74
  75 /* ------------------------------------------------------------------------ */
  76
  77 void owrite(BuildCtx *ctx, const void *ptr, size_t sz)
  78 {
  79   if (fwrite(ptr, 1, sz, ctx->fp) != sz) {
  80     fprintf(stderr, "Error: cannot write to output file: %s\n",
  81             strerror(errno));
  82     exit(1);
  83   }
  84 }
  85
  86 /* ------------------------------------------------------------------------ */
  87
  88 /* Emit code as raw bytes. Only used for DynASM debugging. */
  89 static void emit_raw(BuildCtx *ctx)
  90 {
  91   owrite(ctx, ctx->code, ctx->codesz);
  92 }
  93
  94 /* -- Build machine code -------------------------------------------------- */
  95
  96 static const char *sym_decorate(BuildCtx *ctx,
  97                                 const char *prefix, const char *suffix)
  98 {
  99   char name[256];
 100   char *p;
 101 #if LJ_64
 102   const char *symprefix = ctx->mode == BUILD_machasm ? "_" : "";
 103 #elif LJ_TARGET_XBOX360
 104   const char *symprefix = "";
 105 #else
 106   const char *symprefix = ctx->mode != BUILD_elfasm ? "_" : "";
 107 #endif
 108   sprintf(name, "%s%s%s", symprefix, prefix, suffix);
 109   p = strchr(name, '@');
 110   if (p) {
 111 #if LJ_TARGET_X86ORX64
 112     if (!LJ_64 && (ctx->mode == BUILD_coffasm || ctx->mode == BUILD_peobj))
 113       name[0] = '@';
 114     else
 115       *p = '\0';
 116 #elif (LJ_TARGET_PPC  || LJ_TARGET_PPCSPE) && !LJ_TARGET_CONSOLE
 117     /* Keep @plt. */
 118 #else
 119     *p = '\0';
 120 #endif
 121   }
 122   p = (char *)malloc(strlen(name)+1);  /* MSVC doesn't like strdup. */
 123   strcpy(p, name);
 124   return p;
 125 }
 126
 127 #define NRELOCSYM       (sizeof(extnames)/sizeof(extnames[0])-1)
 128
 129 static int relocmap[NRELOCSYM];
 130
 131 /* Collect external relocations. */
 132 static int collect_reloc(BuildCtx *ctx, uint8_t *addr, int idx, int type)
 133 {
 134   if (ctx->nreloc >= BUILD_MAX_RELOC) {
 135     fprintf(stderr, "Error: too many relocations, increase BUILD_MAX_RELOC.\n");
 136     exit(1);
 137   }
 138   if (relocmap[idx] < 0) {
 139     relocmap[idx] = ctx->nrelocsym;
 140     ctx->relocsym[ctx->nrelocsym] = sym_decorate(ctx, "", extnames[idx]);
 141     ctx->nrelocsym++;
 142   }
 143   ctx->reloc[ctx->nreloc].ofs = (int32_t)(addr - ctx->code);
 144   ctx->reloc[ctx->nreloc].sym = relocmap[idx];
 145   ctx->reloc[ctx->nreloc].type = type;
 146   ctx->nreloc++;
 147 #if LJ_TARGET_XBOX360
 148   return (int)(ctx->code - addr) + 4;  /* Encode symbol offset of .text. */
 149 #else
 150   return 0;  /* Encode symbol offset of 0. */
 151 #endif
 152 }
 153
 154 /* Naive insertion sort. Performance doesn't matter here. */
 155 static void sym_insert(BuildCtx *ctx, int32_t ofs,
 156                        const char *prefix, const char *suffix)
 157 {
 158   ptrdiff_t i = ctx->nsym++;
 159   while (i > 0) {
 160     if (ctx->sym[i-1].ofs <= ofs)
 161       break;
 162     ctx->sym[i] = ctx->sym[i-1];
 163     i--;
 164   }
 165   ctx->sym[i].ofs = ofs;
 166   ctx->sym[i].name = sym_decorate(ctx, prefix, suffix);
 167 }
 168
 169 /* Build the machine code. */
 170 static int build_code(BuildCtx *ctx)
 171 {
 172   int status;
 173   int i;
 174
 175   /* Initialize DynASM structures. */
 176   ctx->nglob = GLOB__MAX;
 177   ctx->glob = (void **)malloc(ctx->nglob*sizeof(void *));
 178   memset(ctx->glob, 0, ctx->nglob*sizeof(void *));
 179   ctx->nreloc = 0;
 180
 181   ctx->globnames = globnames;
 182   ctx->relocsym = (const char **)malloc(NRELOCSYM*sizeof(const char *));
 183   ctx->nrelocsym = 0;
 184   for (i = 0; i < (int)NRELOCSYM; i++) relocmap[i] = -1;
 185
 186   ctx->dasm_ident = DASM_IDENT;
 187   ctx->dasm_arch = DASM_ARCH;
 188
 189   dasm_init(Dst, DASM_MAXSECTION);
 190   dasm_setupglobal(Dst, ctx->glob, ctx->nglob);
 191   dasm_setup(Dst, build_actionlist);
 192
 193   /* Call arch-specific backend to emit the code. */
 194   ctx->npc = build_backend(ctx);
 195
 196   /* Finalize the code. */
 197   (void)dasm_checkstep(Dst, -1);
 198   if ((status = dasm_link(Dst, &ctx->codesz))) return status;
 199   ctx->code = (uint8_t *)malloc(ctx->codesz);
 200   if ((status = dasm_encode(Dst, (void *)ctx->code))) return status;
 201
 202   /* Allocate symbol table and bytecode offsets. */
 203   ctx->beginsym = sym_decorate(ctx, "", LABEL_PREFIX "vm_asm_begin");
 204   ctx->sym = (BuildSym *)malloc((ctx->npc+ctx->nglob+1)*sizeof(BuildSym));
 205   ctx->nsym = 0;
 206   ctx->bc_ofs = (int32_t *)malloc(ctx->npc*sizeof(int32_t));
 207
 208   /* Collect the opcodes (PC labels). */
 209   for (i = 0; i < ctx->npc; i++) {
 210     int32_t ofs = dasm_getpclabel(Dst, i);
 211     if (ofs < 0) return 0x22000000|i;
 212     ctx->bc_ofs[i] = ofs;
 213     if ((LJ_HASJIT ||
 214          !(i == BC_JFORI || i == BC_JFORL || i == BC_JITERL || i == BC_JLOOP ||
 215            i == BC_IFORL || i == BC_IITERL || i == BC_ILOOP)) &&
 216         (LJ_HASFFI || i != BC_KCDATA))
 217       sym_insert(ctx, ofs, LABEL_PREFIX_BC, bc_names[i]);
 218   }
 219
 220   /* Collect the globals (named labels). */
 221   for (i = 0; i < ctx->nglob; i++) {
 222     const char *gl = globnames[i];
 223     int len = (int)strlen(gl);
 224     if (!ctx->glob[i]) {
 225       fprintf(stderr, "Error: undefined global %s\n", gl);
 226       exit(2);
 227     }
 228     /* Skip the _Z symbols. */
 229     if (!(len >= 2 && gl[len-2] == '_' && gl[len-1] == 'Z'))
 230       sym_insert(ctx, (int32_t)((uint8_t *)(ctx->glob[i]) - ctx->code),
 231                  LABEL_PREFIX, globnames[i]);
 232   }
 233
 234   /* Close the address range. */
 235   sym_insert(ctx, (int32_t)ctx->codesz, "", "");
 236   ctx->nsym--;
 237
 238   dasm_free(Dst);
 239
 240   return 0;
 241 }
 242
 243 /* -- Generate VM enums --------------------------------------------------- */
 244
 245 const char *const bc_names[] = {
 246 #define BCNAME(name, ma, mb, mc, mt)       #name,
 247 BCDEF(BCNAME)
 248 #undef BCNAME
 249   NULL
 250 };
 251
 252 const char *const ir_names[] = {
 253 #define IRNAME(name, m, m1, m2) #name,
 254 IRDEF(IRNAME)
 255 #undef IRNAME
 256   NULL
 257 };
 258
 259 const char *const irt_names[] = {
 260 #define IRTNAME(name, size)     #name,
 261 IRTDEF(IRTNAME)
 262 #undef IRTNAME
 263   NULL
 264 };
 265
 266 const char *const irfpm_names[] = {
 267 #define FPMNAME(name)           #name,
 268 IRFPMDEF(FPMNAME)
 269 #undef FPMNAME
 270   NULL
 271 };
 272
 273 const char *const irfield_names[] = {
 274 #define FLNAME(name, ofs)       #name,
 275 IRFLDEF(FLNAME)
 276 #undef FLNAME
 277   NULL
 278 };
 279
 280 const char *const ircall_names[] = {
 281 #define IRCALLNAME(cond, name, nargs, kind, type, flags)        #name,
 282 IRCALLDEF(IRCALLNAME)
 283 #undef IRCALLNAME
 284   NULL
 285 };
 286
 287 static const char *const trace_errors[] = {
 288 #define TREDEF(name, msg)       msg,
 289 #include "lj_traceerr.h"
 290   NULL
 291 };
 292
 293 static const char *lower(char *buf, const char *s)
 294 {
 295   char *p = buf;
 296   while (*s) {
 297     *p++ = (*s >= 'A' && *s <= 'Z') ? *s+0x20 : *s;
 298     s++;
 299   }
 300   *p = '\0';
 301   return buf;
 302 }
 303
 304 /* Emit C source code for bytecode-related definitions. */
 305 static void emit_bcdef(BuildCtx *ctx)
 306 {
 307   int i;
 308   fprintf(ctx->fp, "/* This is a generated file. DO NOT EDIT! */\n\n");
 309   fprintf(ctx->fp, "LJ_DATADEF const uint16_t lj_bc_ofs[] = {\n");
 310   for (i = 0; i < ctx->npc; i++) {
 311     if (i != 0)
 312       fprintf(ctx->fp, ",\n");
 313     fprintf(ctx->fp, "%d", ctx->bc_ofs[i]);
 314   }
 315 }
 316
 317 /* Emit VM definitions as Lua code for debug modules. */
 318 static void emit_vmdef(BuildCtx *ctx)
 319 {
 320   char buf[80];
 321   int i;
 322   fprintf(ctx->fp, "-- This is a generated file. DO NOT EDIT!\n\n");
 323   fprintf(ctx->fp, "return {\n\n");
 324
 325   fprintf(ctx->fp, "bcnames = \"");
 326   for (i = 0; bc_names[i]; i++) fprintf(ctx->fp, "%-6s", bc_names[i]);
 327   fprintf(ctx->fp, "\",\n\n");
 328
 329   fprintf(ctx->fp, "irnames = \"");
 330   for (i = 0; ir_names[i]; i++) fprintf(ctx->fp, "%-6s", ir_names[i]);
 331   fprintf(ctx->fp, "\",\n\n");
 332
 333   fprintf(ctx->fp, "irfpm = { [0]=");
 334   for (i = 0; irfpm_names[i]; i++)
 335     fprintf(ctx->fp, "\"%s\", ", lower(buf, irfpm_names[i]));
 336   fprintf(ctx->fp, "},\n\n");
 337
 338   fprintf(ctx->fp, "irfield = { [0]=");
 339   for (i = 0; irfield_names[i]; i++) {
 340     char *p;
 341     lower(buf, irfield_names[i]);
 342     p = strchr(buf, '_');
 343     if (p) *p = '.';
 344     fprintf(ctx->fp, "\"%s\", ", buf);
 345   }
 346   fprintf(ctx->fp, "},\n\n");
 347
 348   fprintf(ctx->fp, "ircall = {\n[0]=");
 349   for (i = 0; ircall_names[i]; i++)
 350     fprintf(ctx->fp, "\"%s\",\n", ircall_names[i]);
 351   fprintf(ctx->fp, "},\n\n");
 352
 353   fprintf(ctx->fp, "traceerr = {\n[0]=");
 354   for (i = 0; trace_errors[i]; i++)
 355     fprintf(ctx->fp, "\"%s\",\n", trace_errors[i]);
 356   fprintf(ctx->fp, "},\n\n");
 357 }
 358
 359 /* -- Argument parsing ---------------------------------------------------- */
 360
 361 /* Build mode names. */
 362 static const char *const modenames[] = {
 363 #define BUILDNAME(name)         #name,
 364 BUILDDEF(BUILDNAME)
 365 #undef BUILDNAME
 366   NULL
 367 };
 368
 369 /* Print usage information and exit. */
 370 static void usage(void)
 371 {
 372   int i;
 373   fprintf(stderr, LUAJIT_VERSION " VM builder.\n");
 374   fprintf(stderr, LUAJIT_COPYRIGHT ", " LUAJIT_URL "\n");
 375   fprintf(stderr, "Target architecture: " LJ_ARCH_NAME "\n\n");
 376   fprintf(stderr, "Usage: buildvm -m mode [-o outfile] [infiles...]\n\n");
 377   fprintf(stderr, "Available modes:\n");
 378   for (i = 0; i < BUILD__MAX; i++)
 379     fprintf(stderr, "  %s\n", modenames[i]);
 380   exit(1);
 381 }
 382
 383 /* Parse the output mode name. */
 384 static BuildMode parsemode(const char *mode)
 385 {
 386   int i;
 387   for (i = 0; modenames[i]; i++)
 388     if (!strcmp(mode, modenames[i]))
 389       return (BuildMode)i;
 390   usage();
 391   return (BuildMode)-1;
 392 }
 393
 394 /* Parse arguments. */
 395 static void parseargs(BuildCtx *ctx, char **argv)
 396 {
 397   const char *a;
 398   int i;
 399   ctx->mode = (BuildMode)-1;
 400   ctx->outname = "-";
 401   for (i = 1; (a = argv[i]) != NULL; i++) {
 402     if (a[0] != '-')
 403       break;
 404     switch (a[1]) {
 405     case '-':
 406       if (a[2]) goto err;
 407       i++;
 408       goto ok;
 409     case '\0':
 410       goto ok;
 411     case 'm':
 412       i++;
 413       if (a[2] || argv[i] == NULL) goto err;
 414       ctx->mode = parsemode(argv[i]);
 415       break;
 416     case 'o':
 417       i++;
 418       if (a[2] || argv[i] == NULL) goto err;
 419       ctx->outname = argv[i];
 420       break;
 421     default: err:
 422       usage();
 423       break;
 424     }
 425   }
 426 ok:
 427   ctx->args = argv+i;
 428   if (ctx->mode == (BuildMode)-1) goto err;
 429 }
 430
 431 int main(int argc, char **argv)
 432 {
 433   BuildCtx ctx_;
 434   BuildCtx *ctx = &ctx_;
 435   int status, binmode;
 436
 437   if (sizeof(void *) != 4*LJ_32+8*LJ_64) {
 438     fprintf(stderr,"Error: pointer size mismatch in cross-build.\n");
 439     fprintf(stderr,"Try: make HOST_CC=\"gcc -m32\" CROSS=...\n\n");
 440     return 1;
 441   }
 442
 443   UNUSED(argc);
 444   parseargs(ctx, argv);
 445
 446   if ((status = build_code(ctx))) {
 447     fprintf(stderr,"Error: DASM error %08x\n", status);
 448     return 1;
 449   }
 450
 451   switch (ctx->mode) {
 452   case BUILD_peobj:
 453   case BUILD_raw:
 454     binmode = 1;
 455     break;
 456   default:
 457     binmode = 0;
 458     break;
 459   }
 460
 461   if (ctx->outname[0] == '-' && ctx->outname[1] == '\0') {
 462     ctx->fp = stdout;
 463 #if defined(_WIN32)
 464     if (binmode)
 465       _setmode(_fileno(stdout), _O_BINARY);  /* Yuck. */
 466 #endif
 467   } else if (!(ctx->fp = fopen(ctx->outname, binmode ? "wb" : "w"))) {
 468     fprintf(stderr, "Error: cannot open output file '%s': %s\n",
 469             ctx->outname, strerror(errno));
 470     exit(1);
 471   }
 472
 473   switch (ctx->mode) {
 474   case BUILD_elfasm:
 475   case BUILD_coffasm:
 476   case BUILD_machasm:
 477     emit_asm(ctx);
 478     emit_asm_debug(ctx);
 479     break;
 480   case BUILD_peobj:
 481     emit_peobj(ctx);
 482     break;
 483   case BUILD_raw:
 484     emit_raw(ctx);
 485     break;
 486   case BUILD_bcdef:
 487     emit_bcdef(ctx);
 488     emit_lib(ctx);
 489     break;
 490   case BUILD_vmdef:
 491     emit_vmdef(ctx);
 492     emit_lib(ctx);
 493     fprintf(ctx->fp, "}\n\n");
 494     break;
 495   case BUILD_ffdef:
 496   case BUILD_libdef:
 497   case BUILD_recdef:
 498     emit_lib(ctx);
 499     break;
 500   case BUILD_folddef:
 501     emit_fold(ctx);
 502     break;
 503   default:
 504     break;
 505   }
 506
 507   fflush(ctx->fp);
 508   if (ferror(ctx->fp)) {
 509     fprintf(stderr, "Error: cannot write to output file: %s\n",
 510             strerror(errno));
 511     exit(1);
 512   }
 513   fclose(ctx->fp);
 514
 515   return 0;
 516 }
 517