dyngen.c

   1 /*
   2  *  Generic Dynamic compiler generator
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <stdarg.h>
  24 #include <inttypes.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27
  28 #include "config.h"
  29
  30 /* elf format definitions. We use these macros to test the CPU to
  31    allow cross compilation (this tool must be ran on the build
  32    platform) */
  33 #if defined(HOST_I386)
  34
  35 #define ELF_CLASS       ELFCLASS32
  36 #define ELF_ARCH        EM_386
  37 #define elf_check_arch(x) ( ((x) == EM_386) || ((x) == EM_486) )
  38 #undef ELF_USES_RELOCA
  39
  40 #elif defined(HOST_PPC)
  41
  42 #define ELF_CLASS       ELFCLASS32
  43 #define ELF_ARCH        EM_PPC
  44 #define elf_check_arch(x) ((x) == EM_PPC)
  45 #define ELF_USES_RELOCA
  46
  47 #elif defined(HOST_S390)
  48
  49 #define ELF_CLASS       ELFCLASS32
  50 #define ELF_ARCH        EM_S390
  51 #define elf_check_arch(x) ((x) == EM_S390)
  52 #define ELF_USES_RELOCA
  53
  54 #elif defined(HOST_ALPHA)
  55
  56 #define ELF_CLASS       ELFCLASS64
  57 #define ELF_ARCH        EM_ALPHA
  58 #define elf_check_arch(x) ((x) == EM_ALPHA)
  59 #define ELF_USES_RELOCA
  60
  61 #else
  62 #error unsupported CPU - please update the code
  63 #endif
  64
  65 #if ELF_CLASS == ELFCLASS32
  66 typedef int32_t host_long;
  67 typedef uint32_t host_ulong;
  68 #else
  69 typedef int64_t host_long;
  70 typedef uint64_t host_ulong;
  71 #endif
  72
  73 #include "elf.h"
  74
  75 #include "thunk.h"
  76
  77 /* all dynamically generated functions begin with this code */
  78 #define OP_PREFIX "op_"
  79
  80 int elf_must_swap(struct elfhdr *h)
  81 {
  82   union {
  83       uint32_t i;
  84       uint8_t b[4];
  85   } swaptest;
  86
  87   swaptest.i = 1;
  88   return (h->e_ident[EI_DATA] == ELFDATA2MSB) !=
  89       (swaptest.b[0] == 0);
  90 }
  91
  92 void swab16s(uint16_t *p)
  93 {
  94     *p = bswap16(*p);
  95 }
  96
  97 void swab32s(uint32_t *p)
  98 {
  99     *p = bswap32(*p);
 100 }
 101
 102 void swab64s(uint64_t *p)
 103 {
 104     *p = bswap64(*p);
 105 }
 106
 107 #if ELF_CLASS == ELFCLASS32
 108 #define swabls(x) swab32s(x)
 109 #else
 110 #define swabls(x) swab64s(x)
 111 #endif
 112
 113 void elf_swap_ehdr(struct elfhdr *h)
 114 {
 115     swab16s(&h->e_type);                        /* Object file type */
 116     swab16s(&h->        e_machine);             /* Architecture */
 117     swab32s(&h->        e_version);             /* Object file version */
 118     swabls(&h-> e_entry);               /* Entry point virtual address */
 119     swabls(&h-> e_phoff);               /* Program header table file offset */
 120     swabls(&h-> e_shoff);               /* Section header table file offset */
 121     swab32s(&h->        e_flags);               /* Processor-specific flags */
 122     swab16s(&h->        e_ehsize);              /* ELF header size in bytes */
 123     swab16s(&h->        e_phentsize);           /* Program header table entry size */
 124     swab16s(&h->        e_phnum);               /* Program header table entry count */
 125     swab16s(&h->        e_shentsize);           /* Section header table entry size */
 126     swab16s(&h->        e_shnum);               /* Section header table entry count */
 127     swab16s(&h->        e_shstrndx);            /* Section header string table index */
 128 }
 129
 130 void elf_swap_shdr(struct elf_shdr *h)
 131 {
 132   swab32s(&h->  sh_name);               /* Section name (string tbl index) */
 133   swab32s(&h->  sh_type);               /* Section type */
 134   swabls(&h->   sh_flags);              /* Section flags */
 135   swabls(&h->   sh_addr);               /* Section virtual addr at execution */
 136   swabls(&h->   sh_offset);             /* Section file offset */
 137   swabls(&h->   sh_size);               /* Section size in bytes */
 138   swab32s(&h->  sh_link);               /* Link to another section */
 139   swab32s(&h->  sh_info);               /* Additional section information */
 140   swabls(&h->   sh_addralign);          /* Section alignment */
 141   swabls(&h->   sh_entsize);            /* Entry size if section holds table */
 142 }
 143
 144 void elf_swap_phdr(struct elf_phdr *h)
 145 {
 146     swab32s(&h->p_type);                        /* Segment type */
 147     swabls(&h->p_offset);               /* Segment file offset */
 148     swabls(&h->p_vaddr);                /* Segment virtual address */
 149     swabls(&h->p_paddr);                /* Segment physical address */
 150     swabls(&h->p_filesz);               /* Segment size in file */
 151     swabls(&h->p_memsz);                /* Segment size in memory */
 152     swab32s(&h->p_flags);               /* Segment flags */
 153     swabls(&h->p_align);                /* Segment alignment */
 154 }
 155
 156 int do_swap;
 157
 158 uint16_t get16(uint16_t *p)
 159 {
 160     uint16_t val;
 161     val = *p;
 162     if (do_swap)
 163         val = bswap16(val);
 164     return val;
 165 }
 166
 167 uint32_t get32(uint32_t *p)
 168 {
 169     uint32_t val;
 170     val = *p;
 171     if (do_swap)
 172         val = bswap32(val);
 173     return val;
 174 }
 175
 176 void put16(uint16_t *p, uint16_t val)
 177 {
 178     if (do_swap)
 179         val = bswap16(val);
 180     *p = val;
 181 }
 182
 183 void put32(uint32_t *p, uint32_t val)
 184 {
 185     if (do_swap)
 186         val = bswap32(val);
 187     *p = val;
 188 }
 189
 190 void __attribute__((noreturn)) error(const char *fmt, ...)
 191 {
 192     va_list ap;
 193     va_start(ap, fmt);
 194     fprintf(stderr, "dyngen: ");
 195     vfprintf(stderr, fmt, ap);
 196     fprintf(stderr, "\n");
 197     va_end(ap);
 198     exit(1);
 199 }
 200
 201
 202 struct elf_shdr *find_elf_section(struct elf_shdr *shdr, int shnum, const char *shstr,
 203                                   const char *name)
 204 {
 205     int i;
 206     const char *shname;
 207     struct elf_shdr *sec;
 208
 209     for(i = 0; i < shnum; i++) {
 210         sec = &shdr[i];
 211         if (!sec->sh_name)
 212             continue;
 213         shname = shstr + sec->sh_name;
 214         if (!strcmp(shname, name))
 215             return sec;
 216     }
 217     return NULL;
 218 }
 219
 220 void *load_data(int fd, long offset, unsigned int size)
 221 {
 222     char *data;
 223
 224     data = malloc(size);
 225     if (!data)
 226         return NULL;
 227     lseek(fd, offset, SEEK_SET);
 228     if (read(fd, data, size) != size) {
 229         free(data);
 230         return NULL;
 231     }
 232     return data;
 233 }
 234
 235 int strstart(const char *str, const char *val, const char **ptr)
 236 {
 237     const char *p, *q;
 238     p = str;
 239     q = val;
 240     while (*q != '\0') {
 241         if (*p != *q)
 242             return 0;
 243         p++;
 244         q++;
 245     }
 246     if (ptr)
 247         *ptr = p;
 248     return 1;
 249 }
 250
 251 #define MAX_ARGS 3
 252
 253 /* generate op code */
 254 void gen_code(const char *name, host_ulong offset, host_ulong size,
 255               FILE *outfile, uint8_t *text, ELF_RELOC *relocs, int nb_relocs, int reloc_sh_type,
 256               ElfW(Sym) *symtab, char *strtab, int gen_switch)
 257 {
 258     int copy_size = 0;
 259     uint8_t *p_start, *p_end;
 260     int nb_args, i, n;
 261     uint8_t args_present[MAX_ARGS];
 262     const char *sym_name, *p;
 263     ELF_RELOC *rel;
 264
 265     /* compute exact size excluding return instruction */
 266     p_start = text + offset;
 267     p_end = p_start + size;
 268     switch(ELF_ARCH) {
 269     case EM_386:
 270         {
 271             uint8_t *p;
 272             p = p_end - 1;
 273             if (p == p_start)
 274                 error("empty code for %s", name);
 275             if (p[0] != 0xc3)
 276                 error("ret expected at the end of %s", name);
 277             copy_size = p - p_start;
 278         }
 279         break;
 280     case EM_PPC:
 281         {
 282             uint8_t *p;
 283             p = (void *)(p_end - 4);
 284             if (p == p_start)
 285                 error("empty code for %s", name);
 286             if (get32((uint32_t *)p) != 0x4e800020)
 287                 error("blr expected at the end of %s", name);
 288             copy_size = p - p_start;
 289         }
 290         break;
 291     case EM_S390:
 292         {
 293             uint8_t *p;
 294             p = (void *)(p_end - 2);
 295             if (p == p_start)
 296                 error("empty code for %s", name);
 297             if (get16((uint16_t *)p) != 0x07fe && get16((uint16_t *)p) != 0x07f4)
 298                 error("br %r14 expected at the end of %s", name);
 299             copy_size = p - p_start;
 300         }
 301         break;
 302     }
 303
 304     /* compute the number of arguments by looking at the relocations */
 305     for(i = 0;i < MAX_ARGS; i++)
 306         args_present[i] = 0;
 307
 308     for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
 309         if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
 310             sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
 311             if (strstart(sym_name, "__op_param", &p)) {
 312                 n = strtoul(p, NULL, 10);
 313                 if (n >= MAX_ARGS)
 314                     error("too many arguments in %s", name);
 315                 args_present[n - 1] = 1;
 316             }
 317         }
 318     }
 319
 320     nb_args = 0;
 321     while (nb_args < MAX_ARGS && args_present[nb_args])
 322         nb_args++;
 323     for(i = nb_args; i < MAX_ARGS; i++) {
 324         if (args_present[i])
 325             error("inconsistent argument numbering in %s", name);
 326     }
 327
 328     if (gen_switch == 2) {
 329         fprintf(outfile, "DEF(%s, %d)\n", name + 3, nb_args);
 330     } else if (gen_switch == 1) {
 331
 332         /* output C code */
 333         fprintf(outfile, "case INDEX_%s: {\n", name);
 334         if (nb_args > 0) {
 335             fprintf(outfile, "    long ");
 336             for(i = 0; i < nb_args; i++) {
 337                 if (i != 0)
 338                     fprintf(outfile, ", ");
 339                 fprintf(outfile, "param%d", i + 1);
 340             }
 341             fprintf(outfile, ";\n");
 342         }
 343         fprintf(outfile, "    extern void %s();\n", name);
 344
 345         for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
 346             if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
 347                 sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
 348                 if (!strstart(sym_name, "__op_param", &p)) {
 349                     fprintf(outfile, "extern char %s;\n", sym_name);
 350                 }
 351             }
 352         }
 353
 354         fprintf(outfile, "    memcpy(gen_code_ptr, &%s, %d);\n", name, copy_size);
 355         for(i = 0; i < nb_args; i++) {
 356             fprintf(outfile, "    param%d = *opparam_ptr++;\n", i + 1);
 357         }
 358
 359         /* patch relocations */
 360 #if defined(HOST_I386)
 361             {
 362                 char name[256];
 363                 int type;
 364                 int addend;
 365                 for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
 366                 if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
 367                     sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
 368                     if (strstart(sym_name, "__op_param", &p)) {
 369                         snprintf(name, sizeof(name), "param%s", p);
 370                     } else {
 371                         snprintf(name, sizeof(name), "(long)(&%s)", sym_name);
 372                     }
 373                     type = ELF32_R_TYPE(rel->r_info);
 374                     addend = get32((uint32_t *)(text + rel->r_offset));
 375                     switch(type) {
 376                     case R_386_32:
 377                         fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n",
 378                                 rel->r_offset - offset, name, addend);
 379                         break;
 380                     case R_386_PC32:
 381                         fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n",
 382                                 rel->r_offset - offset, name, rel->r_offset - offset, addend);
 383                         break;
 384                     default:
 385                         error("unsupported i386 relocation (%d)", type);
 386                     }
 387                 }
 388                 }
 389             }
 390 #elif defined(HOST_PPC)
 391             {
 392                 char name[256];
 393                 int type;
 394                 int addend;
 395                 for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
 396                     if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
 397                         sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
 398                         if (strstart(sym_name, "__op_param", &p)) {
 399                             snprintf(name, sizeof(name), "param%s", p);
 400                         } else {
 401                             snprintf(name, sizeof(name), "(long)(&%s)", sym_name);
 402                         }
 403                         type = ELF32_R_TYPE(rel->r_info);
 404                         addend = rel->r_addend;
 405                         switch(type) {
 406                         case R_PPC_ADDR32:
 407                             fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n",
 408                                     rel->r_offset - offset, name, addend);
 409                             break;
 410                         case R_PPC_ADDR16_LO:
 411                             fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d);\n",
 412                                     rel->r_offset - offset, name, addend);
 413                             break;
 414                         case R_PPC_ADDR16_HI:
 415                             fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d) >> 16;\n",
 416                                     rel->r_offset - offset, name, addend);
 417                             break;
 418                         case R_PPC_ADDR16_HA:
 419                             fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d + 0x8000) >> 16;\n",
 420                                     rel->r_offset - offset, name, addend);
 421                             break;
 422                         case R_PPC_REL24:
 423                             /* warning: must be at 32 MB distancy */
 424                             fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((%s - (long)(gen_code_ptr + %d) + %d) & 0x03fffffc);\n",
 425                                     rel->r_offset - offset, rel->r_offset - offset, name, rel->r_offset - offset, addend);
 426                             break;
 427                         default:
 428                             error("unsupported powerpc relocation (%d)", type);
 429                         }
 430                     }
 431                 }
 432             }
 433 #elif defined(HOST_S390)
 434             {
 435                 char name[256];
 436                 int type;
 437                 int addend;
 438                 for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
 439                     if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
 440                         sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
 441                         if (strstart(sym_name, "__op_param", &p)) {
 442                             snprintf(name, sizeof(name), "param%s", p);
 443                         } else {
 444                             snprintf(name, sizeof(name), "(long)(&%s)", sym_name);
 445                         }
 446                         type = ELF32_R_TYPE(rel->r_info);
 447                         addend = rel->r_addend;
 448                         switch(type) {
 449                         case R_390_32:
 450                             fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n",
 451                                     rel->r_offset - offset, name, addend);
 452                             break;
 453                         case R_390_16:
 454                             fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = %s + %d;\n",
 455                                     rel->r_offset - offset, name, addend);
 456                             break;
 457                         case R_390_8:
 458                             fprintf(outfile, "    *(uint8_t *)(gen_code_ptr + %d) = %s + %d;\n",
 459                                     rel->r_offset - offset, name, addend);
 460                             break;
 461                         default:
 462                             error("unsupported s390 relocation (%d)", type);
 463                         }
 464                     }
 465                 }
 466             }
 467 #else
 468 #error unsupported CPU
 469 #endif
 470         fprintf(outfile, "    gen_code_ptr += %d;\n", copy_size);
 471         fprintf(outfile, "}\n");
 472         fprintf(outfile, "break;\n\n");
 473     } else {
 474         fprintf(outfile, "static inline void gen_%s(", name);
 475         if (nb_args == 0) {
 476             fprintf(outfile, "void");
 477         } else {
 478             for(i = 0; i < nb_args; i++) {
 479                 if (i != 0)
 480                     fprintf(outfile, ", ");
 481                 fprintf(outfile, "long param%d", i + 1);
 482             }
 483         }
 484         fprintf(outfile, ")\n");
 485         fprintf(outfile, "{\n");
 486         for(i = 0; i < nb_args; i++) {
 487             fprintf(outfile, "    *gen_opparam_ptr++ = param%d;\n", i + 1);
 488         }
 489         fprintf(outfile, "    *gen_opc_ptr++ = INDEX_%s;\n", name);
 490         fprintf(outfile, "}\n\n");
 491     }
 492 }
 493
 494 /* load an elf object file */
 495 int load_elf(const char *filename, FILE *outfile, int do_print_enum)
 496 {
 497     int fd;
 498     struct elfhdr ehdr;
 499     struct elf_shdr *sec, *shdr, *symtab_sec, *strtab_sec, *text_sec;
 500     int i, j, nb_syms;
 501     ElfW(Sym) *symtab, *sym;
 502     char *shstr, *strtab;
 503     uint8_t *text;
 504     void *relocs;
 505     int nb_relocs, reloc_sh_type;
 506
 507     fd = open(filename, O_RDONLY);
 508     if (fd < 0)
 509         error("can't open file '%s'", filename);
 510
 511     /* Read ELF header.  */
 512     if (read(fd, &ehdr, sizeof (ehdr)) != sizeof (ehdr))
 513         error("unable to read file header");
 514
 515     /* Check ELF identification.  */
 516     if (ehdr.e_ident[EI_MAG0] != ELFMAG0
 517      || ehdr.e_ident[EI_MAG1] != ELFMAG1
 518      || ehdr.e_ident[EI_MAG2] != ELFMAG2
 519      || ehdr.e_ident[EI_MAG3] != ELFMAG3
 520      || ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
 521         error("bad ELF header");
 522     }
 523
 524     do_swap = elf_must_swap(&ehdr);
 525     if (do_swap)
 526         elf_swap_ehdr(&ehdr);
 527     if (ehdr.e_ident[EI_CLASS] != ELF_CLASS)
 528         error("Unsupported ELF class");
 529     if (ehdr.e_type != ET_REL)
 530         error("ELF object file expected");
 531     if (ehdr.e_version != EV_CURRENT)
 532         error("Invalid ELF version");
 533     if (!elf_check_arch(ehdr.e_machine))
 534         error("Unsupported CPU (e_machine=%d)", ehdr.e_machine);
 535
 536     /* read section headers */
 537     shdr = load_data(fd, ehdr.e_shoff, ehdr.e_shnum * sizeof(struct elf_shdr));
 538     if (do_swap) {
 539         for(i = 0; i < ehdr.e_shnum; i++) {
 540             elf_swap_shdr(&shdr[i]);
 541         }
 542     }
 543
 544     sec = &shdr[ehdr.e_shstrndx];
 545     shstr = load_data(fd, sec->sh_offset, sec->sh_size);
 546
 547     /* text section */
 548
 549     text_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".text");
 550     if (!text_sec)
 551         error("could not find .text section");
 552     text = load_data(fd, text_sec->sh_offset, text_sec->sh_size);
 553
 554     /* find text relocations, if any */
 555     nb_relocs = 0;
 556     relocs = NULL;
 557     reloc_sh_type = 0;
 558     for(i = 0; i < ehdr.e_shnum; i++) {
 559         sec = &shdr[i];
 560         if ((sec->sh_type == SHT_REL || sec->sh_type == SHT_RELA) &&
 561             sec->sh_info == (text_sec - shdr)) {
 562             reloc_sh_type = sec->sh_type;
 563             relocs = load_data(fd, sec->sh_offset, sec->sh_size);
 564             nb_relocs = sec->sh_size / sec->sh_entsize;
 565             if (do_swap) {
 566                 if (sec->sh_type == SHT_REL) {
 567                     Elf32_Rel *rel = relocs;
 568                     for(j = 0, rel = relocs; j < nb_relocs; j++, rel++) {
 569                         swab32s(&rel->r_offset);
 570                         swab32s(&rel->r_info);
 571                     }
 572                 } else {
 573                     Elf32_Rela *rel = relocs;
 574                     for(j = 0, rel = relocs; j < nb_relocs; j++, rel++) {
 575                         swab32s(&rel->r_offset);
 576                         swab32s(&rel->r_info);
 577                         swab32s(&rel->r_addend);
 578                     }
 579                 }
 580             }
 581             break;
 582         }
 583     }
 584
 585     symtab_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".symtab");
 586     if (!symtab_sec)
 587         error("could not find .symtab section");
 588     strtab_sec = &shdr[symtab_sec->sh_link];
 589
 590     symtab = load_data(fd, symtab_sec->sh_offset, symtab_sec->sh_size);
 591     strtab = load_data(fd, strtab_sec->sh_offset, strtab_sec->sh_size);
 592
 593     nb_syms = symtab_sec->sh_size / sizeof(Elf32_Sym);
 594     if (do_swap) {
 595         for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
 596             swab32s(&sym->st_name);
 597             swabls(&sym->st_value);
 598             swabls(&sym->st_size);
 599             swab16s(&sym->st_shndx);
 600         }
 601     }
 602
 603     if (do_print_enum) {
 604         fprintf(outfile, "DEF(end, 0)\n");
 605         for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
 606             const char *name, *p;
 607             name = strtab + sym->st_name;
 608             if (strstart(name, OP_PREFIX, &p)) {
 609                 gen_code(name, sym->st_value, sym->st_size, outfile,
 610                          text, relocs, nb_relocs, reloc_sh_type, symtab, strtab, 2);
 611             }
 612         }
 613     } else {
 614         /* generate big code generation switch */
 615 fprintf(outfile,
 616 "int dyngen_code(uint8_t *gen_code_buf,\n"
 617 "                const uint16_t *opc_buf, const uint32_t *opparam_buf)\n"
 618 "{\n"
 619 "    uint8_t *gen_code_ptr;\n"
 620 "    const uint16_t *opc_ptr;\n"
 621 "    const uint32_t *opparam_ptr;\n"
 622 "    gen_code_ptr = gen_code_buf;\n"
 623 "    opc_ptr = opc_buf;\n"
 624 "    opparam_ptr = opparam_buf;\n"
 625 "    for(;;) {\n"
 626 "        switch(*opc_ptr++) {\n"
 627 );
 628
 629         for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
 630             const char *name;
 631             name = strtab + sym->st_name;
 632             if (strstart(name, OP_PREFIX, NULL)) {
 633 #if 0
 634                 printf("%4d: %s pos=0x%08x len=%d\n",
 635                        i, name, sym->st_value, sym->st_size);
 636 #endif
 637                 if (sym->st_shndx != (text_sec - shdr))
 638                     error("invalid section for opcode (0x%x)", sym->st_shndx);
 639                 gen_code(name, sym->st_value, sym->st_size, outfile,
 640                          text, relocs, nb_relocs, reloc_sh_type, symtab, strtab, 1);
 641             }
 642         }
 643
 644 fprintf(outfile,
 645 "        default:\n"
 646 "            goto the_end;\n"
 647 "        }\n"
 648 "    }\n"
 649 " the_end:\n"
 650 );
 651
 652 /* generate a return */
 653     switch(ELF_ARCH) {
 654     case EM_386:
 655         fprintf(outfile, "*gen_code_ptr++ = 0xc3; /* ret */\n");
 656         break;
 657     case EM_PPC:
 658         fprintf(outfile, "*((uint32_t *)gen_code_ptr)++ = 0x4e800020; /* blr */\n");
 659         break;
 660     case EM_S390:
 661         fprintf(outfile, "*((uint16_t *)gen_code_ptr)++ = 0x07fe; /* br %%r14 */\n");
 662         break;
 663     }
 664
 665     fprintf(outfile, "return gen_code_ptr -  gen_code_buf;\n");
 666     fprintf(outfile, "}\n\n");
 667
 668 /* generate gen_xxx functions */
 669 /* XXX: suppress the use of these functions to simplify code */
 670         for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
 671             const char *name;
 672             name = strtab + sym->st_name;
 673             if (strstart(name, OP_PREFIX, NULL)) {
 674                 if (sym->st_shndx != (text_sec - shdr))
 675                     error("invalid section for opcode (0x%x)", sym->st_shndx);
 676                 gen_code(name, sym->st_value, sym->st_size, outfile,
 677                          text, relocs, nb_relocs, reloc_sh_type, symtab, strtab, 0);
 678             }
 679         }
 680     }
 681
 682     close(fd);
 683     return 0;
 684 }
 685
 686 void usage(void)
 687 {
 688     printf("dyngen (c) 2003 Fabrice Bellard\n"
 689            "usage: dyngen [-o outfile] [-c] objfile\n"
 690            "Generate a dynamic code generator from an object file\n"
 691            "-c     output enum of operations\n"
 692            );
 693     exit(1);
 694 }
 695
 696 int main(int argc, char **argv)
 697 {
 698     int c, do_print_enum;
 699     const char *filename, *outfilename;
 700     FILE *outfile;
 701
 702     outfilename = "out.c";
 703     do_print_enum = 0;
 704     for(;;) {
 705         c = getopt(argc, argv, "ho:c");
 706         if (c == -1)
 707             break;
 708         switch(c) {
 709         case 'h':
 710             usage();
 711             break;
 712         case 'o':
 713             outfilename = optarg;
 714             break;
 715         case 'c':
 716             do_print_enum = 1;
 717             break;
 718         }
 719     }
 720     if (optind >= argc)
 721         usage();
 722     filename = argv[optind];
 723     outfile = fopen(outfilename, "w");
 724     if (!outfile)
 725         error("could not open '%s'", outfilename);
 726     load_elf(filename, outfile, do_print_enum);
 727     fclose(outfile);
 728     return 0;
 729 }