tccrun.c

   1 /*
   2  *  TCC - Tiny C Compiler - Support for -run switch
   3  *
   4  *  Copyright (c) 2001-2004 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "tcc.h"
  22
  23 /* only native compiler supports -run */
  24 #ifdef TCC_IS_NATIVE
  25
  26 #ifdef CONFIG_TCC_BACKTRACE
  27 ST_DATA int rt_num_callers = 6;
  28 ST_DATA const char **rt_bound_error_msg;
  29 ST_DATA void *rt_prog_main;
  30 #endif
  31
  32 #ifdef _WIN32
  33 #define ucontext_t CONTEXT
  34 #endif
  35
  36 static void set_pages_executable(void *ptr, unsigned long length);
  37 static void set_exception_handler(void);
  38 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level);
  39 static void rt_error(ucontext_t *uc, const char *fmt, ...);
  40 static int tcc_relocate_ex(TCCState *s1, void *ptr);
  41
  42 #ifdef _WIN64
  43 static void win64_add_function_table(TCCState *s1);
  44 #endif
  45
  46 /* ------------------------------------------------------------- */
  47 /* Do all relocations (needed before using tcc_get_symbol())
  48    Returns -1 on error. */
  49
  50 LIBTCCAPI int tcc_relocate(TCCState *s1, void *ptr)
  51 {
  52     int ret;
  53
  54     if (TCC_RELOCATE_AUTO != ptr)
  55         return tcc_relocate_ex(s1, ptr);
  56
  57 #ifdef HAVE_SELINUX
  58     /* Use mmap instead of malloc for Selinux
  59     Ref http://www.gnu.org/s/libc/manual/html_node/File-Size.html */
  60     char tmpfname[] = "/tmp/.tccrunXXXXXX";
  61     int fd = mkstemp (tmpfname);
  62     if ((ret= tcc_relocate_ex(s1,NULL)) < 0)return -1;
  63     s1->mem_size=ret;
  64     unlink (tmpfname); ftruncate (fd, s1->mem_size);
  65     s1->write_mem = mmap (NULL, ret, PROT_READ|PROT_WRITE,
  66         MAP_SHARED, fd, 0);
  67     if(s1->write_mem == MAP_FAILED){
  68         tcc_error("/tmp not writeable");
  69         return -1;
  70     }
  71     s1->runtime_mem = mmap (NULL, ret, PROT_READ|PROT_EXEC,
  72         MAP_SHARED, fd, 0);
  73     if(s1->runtime_mem == MAP_FAILED){
  74         tcc_error("/tmp not executable");
  75         return -1;
  76     }
  77     ret = tcc_relocate_ex(s1, s1->write_mem);
  78 #else
  79     ret = tcc_relocate_ex(s1, NULL);
  80     if (-1 != ret) {
  81         s1->runtime_mem = tcc_malloc(ret);
  82         ret = tcc_relocate_ex(s1, s1->runtime_mem);
  83     }
  84 #endif
  85     return ret;
  86 }
  87
  88 /* launch the compiled program with the given arguments */
  89 LIBTCCAPI int tcc_run(TCCState *s1, int argc, char **argv)
  90 {
  91     int (*prog_main)(int, char **);
  92     int ret;
  93
  94     if (tcc_relocate(s1, TCC_RELOCATE_AUTO) < 0)
  95         return -1;
  96
  97     prog_main = tcc_get_symbol_err(s1, "main");
  98
  99 #ifdef CONFIG_TCC_BACKTRACE
 100     if (s1->do_debug) {
 101         set_exception_handler();
 102         rt_prog_main = prog_main;
 103     }
 104 #endif
 105
 106 #ifdef CONFIG_TCC_BCHECK
 107     if (s1->do_bounds_check) {
 108         void (*bound_init)(void);
 109         void (*bound_exit)(void);
 110         /* set error function */
 111         rt_bound_error_msg = tcc_get_symbol_err(s1, "__bound_error_msg");
 112         /* XXX: use .init section so that it also work in binary ? */
 113         bound_init = tcc_get_symbol_err(s1, "__bound_init");
 114         bound_exit = tcc_get_symbol_err(s1, "__bound_exit");
 115         bound_init();
 116         ret = (*prog_main)(argc, argv);
 117         bound_exit();
 118     } else
 119 #endif
 120         ret = (*prog_main)(argc, argv);
 121     return ret;
 122 }
 123
 124 /* relocate code. Return -1 on error, required size if ptr is NULL,
 125    otherwise copy code into buffer passed by the caller */
 126 static int tcc_relocate_ex(TCCState *s1, void *ptr)
 127 {
 128     Section *s;
 129     unsigned long offset, length;
 130     addr_t mem;
 131     int i;
 132
 133     if (0 == s1->runtime_added) {
 134         s1->runtime_added = 1;
 135         s1->nb_errors = 0;
 136 #ifdef TCC_TARGET_PE
 137         pe_output_file(s1, NULL);
 138 #else
 139         tcc_add_runtime(s1);
 140         relocate_common_syms();
 141         tcc_add_linker_symbols(s1);
 142         build_got_entries(s1);
 143 #endif
 144         if (s1->nb_errors)
 145             return -1;
 146     }
 147
 148     offset = 0, mem = (addr_t)ptr;
 149     for(i = 1; i < s1->nb_sections; i++) {
 150         s = s1->sections[i];
 151         if (0 == (s->sh_flags & SHF_ALLOC))
 152             continue;
 153         length = s->data_offset;
 154         s->sh_addr = mem ? (mem + offset + 15) & ~15 : 0;
 155         offset = (offset + length + 15) & ~15;
 156     }
 157     offset += 16;
 158
 159     /* relocate symbols */
 160     relocate_syms(s1, 1);
 161     if (s1->nb_errors)
 162         return -1;
 163
 164 #ifdef TCC_HAS_RUNTIME_PLTGOT
 165     s1->runtime_plt_and_got_offset = 0;
 166     s1->runtime_plt_and_got = (char *)(mem + offset);
 167     /* double the size of the buffer for got and plt entries
 168        XXX: calculate exact size for them? */
 169     offset *= 2;
 170 #endif
 171
 172     if (0 == mem)
 173         return offset;
 174
 175     /* relocate each section */
 176     for(i = 1; i < s1->nb_sections; i++) {
 177         s = s1->sections[i];
 178         if (s->reloc)
 179             relocate_section(s1, s);
 180     }
 181
 182     for(i = 1; i < s1->nb_sections; i++) {
 183         s = s1->sections[i];
 184         if (0 == (s->sh_flags & SHF_ALLOC))
 185             continue;
 186         length = s->data_offset;
 187         // printf("%-12s %08x %04x\n", s->name, s->sh_addr, length);
 188         ptr = (void*)s->sh_addr;
 189         if (NULL == s->data || s->sh_type == SHT_NOBITS)
 190             memset(ptr, 0, length);
 191         else
 192             memcpy(ptr, s->data, length);
 193         /* mark executable sections as executable in memory */
 194         if (s->sh_flags & SHF_EXECINSTR)
 195             set_pages_executable(ptr, length);
 196     }
 197
 198 #ifdef TCC_HAS_RUNTIME_PLTGOT
 199     set_pages_executable(s1->runtime_plt_and_got,
 200                          s1->runtime_plt_and_got_offset);
 201 #endif
 202
 203 #ifdef _WIN64
 204     win64_add_function_table(s1);
 205 #endif
 206     return 0;
 207 }
 208
 209 /* ------------------------------------------------------------- */
 210 /* allow to run code in memory */
 211
 212 static void set_pages_executable(void *ptr, unsigned long length)
 213 {
 214 #ifdef _WIN32
 215     unsigned long old_protect;
 216     VirtualProtect(ptr, length, PAGE_EXECUTE_READWRITE, &old_protect);
 217 #else
 218     addr_t start, end;
 219     start = (addr_t)ptr & ~(PAGESIZE - 1);
 220     end = (addr_t)ptr + length;
 221     end = (end + PAGESIZE - 1) & ~(PAGESIZE - 1);
 222     mprotect((void *)start, end - start, PROT_READ | PROT_WRITE | PROT_EXEC);
 223 #endif
 224 }
 225
 226 /* ------------------------------------------------------------- */
 227 #ifdef CONFIG_TCC_BACKTRACE
 228
 229 PUB_FUNC void tcc_set_num_callers(int n)
 230 {
 231     rt_num_callers = n;
 232 }
 233
 234 /* print the position in the source file of PC value 'pc' by reading
 235    the stabs debug information */
 236 static addr_t rt_printline(addr_t wanted_pc, const char *msg)
 237 {
 238     char func_name[128], last_func_name[128];
 239     addr_t func_addr, last_pc, pc;
 240     const char *incl_files[INCLUDE_STACK_SIZE];
 241     int incl_index, len, last_line_num, i;
 242     const char *str, *p;
 243
 244     Stab_Sym *stab_sym = NULL, *stab_sym_end, *sym;
 245     int stab_len = 0;
 246     char *stab_str = NULL;
 247
 248     if (stab_section) {
 249         stab_len = stab_section->data_offset;
 250         stab_sym = (Stab_Sym *)stab_section->data;
 251         stab_str = stabstr_section->data;
 252     }
 253
 254     func_name[0] = '\0';
 255     func_addr = 0;
 256     incl_index = 0;
 257     last_func_name[0] = '\0';
 258     last_pc = (addr_t)-1;
 259     last_line_num = 1;
 260
 261     if (!stab_sym)
 262         goto no_stabs;
 263
 264     stab_sym_end = (Stab_Sym*)((char*)stab_sym + stab_len);
 265     for (sym = stab_sym + 1; sym < stab_sym_end; ++sym) {
 266         switch(sym->n_type) {
 267             /* function start or end */
 268         case N_FUN:
 269             if (sym->n_strx == 0) {
 270                 /* we test if between last line and end of function */
 271                 pc = sym->n_value + func_addr;
 272                 if (wanted_pc >= last_pc && wanted_pc < pc)
 273                     goto found;
 274                 func_name[0] = '\0';
 275                 func_addr = 0;
 276             } else {
 277                 str = stab_str + sym->n_strx;
 278                 p = strchr(str, ':');
 279                 if (!p) {
 280                     pstrcpy(func_name, sizeof(func_name), str);
 281                 } else {
 282                     len = p - str;
 283                     if (len > sizeof(func_name) - 1)
 284                         len = sizeof(func_name) - 1;
 285                     memcpy(func_name, str, len);
 286                     func_name[len] = '\0';
 287                 }
 288                 func_addr = sym->n_value;
 289             }
 290             break;
 291             /* line number info */
 292         case N_SLINE:
 293             pc = sym->n_value + func_addr;
 294             if (wanted_pc >= last_pc && wanted_pc < pc)
 295                 goto found;
 296             last_pc = pc;
 297             last_line_num = sym->n_desc;
 298             /* XXX: slow! */
 299             strcpy(last_func_name, func_name);
 300             break;
 301             /* include files */
 302         case N_BINCL:
 303             str = stab_str + sym->n_strx;
 304         add_incl:
 305             if (incl_index < INCLUDE_STACK_SIZE) {
 306                 incl_files[incl_index++] = str;
 307             }
 308             break;
 309         case N_EINCL:
 310             if (incl_index > 1)
 311                 incl_index--;
 312             break;
 313         case N_SO:
 314             if (sym->n_strx == 0) {
 315                 incl_index = 0; /* end of translation unit */
 316             } else {
 317                 str = stab_str + sym->n_strx;
 318                 /* do not add path */
 319                 len = strlen(str);
 320                 if (len > 0 && str[len - 1] != '/')
 321                     goto add_incl;
 322             }
 323             break;
 324         }
 325     }
 326
 327 no_stabs:
 328     /* second pass: we try symtab symbols (no line number info) */
 329     incl_index = 0;
 330     if (symtab_section)
 331     {
 332         ElfW(Sym) *sym, *sym_end;
 333         int type;
 334
 335         sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
 336         for(sym = (ElfW(Sym) *)symtab_section->data + 1;
 337             sym < sym_end;
 338             sym++) {
 339             type = ELFW(ST_TYPE)(sym->st_info);
 340             if (type == STT_FUNC || type == STT_GNU_IFUNC) {
 341                 if (wanted_pc >= sym->st_value &&
 342                     wanted_pc < sym->st_value + sym->st_size) {
 343                     pstrcpy(last_func_name, sizeof(last_func_name),
 344                             strtab_section->data + sym->st_name);
 345                     func_addr = sym->st_value;
 346                     goto found;
 347                 }
 348             }
 349         }
 350     }
 351     /* did not find any info: */
 352     fprintf(stderr, "%s %p ???\n", msg, (void*)wanted_pc);
 353     fflush(stderr);
 354     return 0;
 355  found:
 356     i = incl_index;
 357     if (i > 0)
 358         fprintf(stderr, "%s:%d: ", incl_files[--i], last_line_num);
 359     fprintf(stderr, "%s %p", msg, (void*)wanted_pc);
 360     if (last_func_name[0] != '\0')
 361         fprintf(stderr, " %s()", last_func_name);
 362     if (--i >= 0) {
 363         fprintf(stderr, " (included from ");
 364         for (;;) {
 365             fprintf(stderr, "%s", incl_files[i]);
 366             if (--i < 0)
 367                 break;
 368             fprintf(stderr, ", ");
 369         }
 370         fprintf(stderr, ")");
 371     }
 372     fprintf(stderr, "\n");
 373     fflush(stderr);
 374     return func_addr;
 375 }
 376
 377 /* emit a run time error at position 'pc' */
 378 static void rt_error(ucontext_t *uc, const char *fmt, ...)
 379 {
 380     va_list ap;
 381     addr_t pc;
 382     int i;
 383
 384     fprintf(stderr, "Runtime error: ");
 385     va_start(ap, fmt);
 386     vfprintf(stderr, fmt, ap);
 387     va_end(ap);
 388     fprintf(stderr, "\n");
 389
 390     for(i=0;i<rt_num_callers;i++) {
 391         if (rt_get_caller_pc(&pc, uc, i) < 0)
 392             break;
 393         pc = rt_printline(pc, i ? "by" : "at");
 394         if (pc == (addr_t)rt_prog_main && pc)
 395             break;
 396     }
 397 }
 398
 399 /* ------------------------------------------------------------- */
 400 #ifndef _WIN32
 401
 402 /* signal handler for fatal errors */
 403 static void sig_error(int signum, siginfo_t *siginf, void *puc)
 404 {
 405     ucontext_t *uc = puc;
 406
 407     switch(signum) {
 408     case SIGFPE:
 409         switch(siginf->si_code) {
 410         case FPE_INTDIV:
 411         case FPE_FLTDIV:
 412             rt_error(uc, "division by zero");
 413             break;
 414         default:
 415             rt_error(uc, "floating point exception");
 416             break;
 417         }
 418         break;
 419     case SIGBUS:
 420     case SIGSEGV:
 421         if (rt_bound_error_msg && *rt_bound_error_msg)
 422             rt_error(uc, *rt_bound_error_msg);
 423         else
 424             rt_error(uc, "dereferencing invalid pointer");
 425         break;
 426     case SIGILL:
 427         rt_error(uc, "illegal instruction");
 428         break;
 429     case SIGABRT:
 430         rt_error(uc, "abort() called");
 431         break;
 432     default:
 433         rt_error(uc, "caught signal %d", signum);
 434         break;
 435     }
 436     exit(255);
 437 }
 438
 439 /* Generate a stack backtrace when a CPU exception occurs. */
 440 static void set_exception_handler(void)
 441 {
 442     struct sigaction sigact;
 443     /* install TCC signal handlers to print debug info on fatal
 444        runtime errors */
 445     sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
 446     sigact.sa_sigaction = sig_error;
 447     sigemptyset(&sigact.sa_mask);
 448     sigaction(SIGFPE, &sigact, NULL);
 449     sigaction(SIGILL, &sigact, NULL);
 450     sigaction(SIGSEGV, &sigact, NULL);
 451     sigaction(SIGBUS, &sigact, NULL);
 452     sigaction(SIGABRT, &sigact, NULL);
 453 }
 454
 455 /* ------------------------------------------------------------- */
 456 #ifdef __i386__
 457
 458 /* fix for glibc 2.1 */
 459 #ifndef REG_EIP
 460 #define REG_EIP EIP
 461 #define REG_EBP EBP
 462 #endif
 463
 464 /* return the PC at frame level 'level'. Return negative if not found */
 465 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 466 {
 467     addr_t fp;
 468     int i;
 469
 470     if (level == 0) {
 471 #if defined(__APPLE__)
 472         *paddr = uc->uc_mcontext->__ss.__eip;
 473 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 474         *paddr = uc->uc_mcontext.mc_eip;
 475 #elif defined(__dietlibc__)
 476         *paddr = uc->uc_mcontext.eip;
 477 #else
 478         *paddr = uc->uc_mcontext.gregs[REG_EIP];
 479 #endif
 480         return 0;
 481     } else {
 482 #if defined(__APPLE__)
 483         fp = uc->uc_mcontext->__ss.__ebp;
 484 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 485         fp = uc->uc_mcontext.mc_ebp;
 486 #elif defined(__dietlibc__)
 487         fp = uc->uc_mcontext.ebp;
 488 #else
 489         fp = uc->uc_mcontext.gregs[REG_EBP];
 490 #endif
 491         for(i=1;i<level;i++) {
 492             /* XXX: check address validity with program info */
 493             if (fp <= 0x1000 || fp >= 0xc0000000)
 494                 return -1;
 495             fp = ((addr_t *)fp)[0];
 496         }
 497         *paddr = ((addr_t *)fp)[1];
 498         return 0;
 499     }
 500 }
 501
 502 /* ------------------------------------------------------------- */
 503 #elif defined(__x86_64__)
 504
 505 /* return the PC at frame level 'level'. Return negative if not found */
 506 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 507 {
 508     addr_t fp;
 509     int i;
 510
 511     if (level == 0) {
 512         /* XXX: only support linux */
 513 #if defined(__APPLE__)
 514         *paddr = uc->uc_mcontext->__ss.__rip;
 515 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 516         *paddr = uc->uc_mcontext.mc_rip;
 517 #else
 518         *paddr = uc->uc_mcontext.gregs[REG_RIP];
 519 #endif
 520         return 0;
 521     } else {
 522 #if defined(__APPLE__)
 523         fp = uc->uc_mcontext->__ss.__rbp;
 524 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 525         fp = uc->uc_mcontext.mc_rbp;
 526 #else
 527         fp = uc->uc_mcontext.gregs[REG_RBP];
 528 #endif
 529         for(i=1;i<level;i++) {
 530             /* XXX: check address validity with program info */
 531             if (fp <= 0x1000)
 532                 return -1;
 533             fp = ((addr_t *)fp)[0];
 534         }
 535         *paddr = ((addr_t *)fp)[1];
 536         return 0;
 537     }
 538 }
 539
 540 /* ------------------------------------------------------------- */
 541 #elif defined(__arm__)
 542
 543 /* return the PC at frame level 'level'. Return negative if not found */
 544 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 545 {
 546     addr_t fp, sp;
 547     int i;
 548
 549     if (level == 0) {
 550         /* XXX: only supports linux */
 551 #if defined(__linux__)
 552         *paddr = uc->uc_mcontext.arm_pc;
 553 #else
 554         return -1;
 555 #endif
 556         return 0;
 557     } else {
 558 #if defined(__linux__)
 559         fp = uc->uc_mcontext.arm_fp;
 560         sp = uc->uc_mcontext.arm_sp;
 561         if (sp < 0x1000)
 562             sp = 0x1000;
 563 #else
 564         return -1;
 565 #endif
 566         /* XXX: specific to tinycc stack frames */
 567         if (fp < sp + 12 || fp & 3)
 568             return -1;
 569         for(i = 1; i < level; i++) {
 570             sp = ((addr_t *)fp)[-2];
 571             if (sp < fp || sp - fp > 16 || sp & 3)
 572                 return -1;
 573             fp = ((addr_t *)fp)[-3];
 574             if (fp <= sp || fp - sp < 12 || fp & 3)
 575                 return -1;
 576         }
 577         /* XXX: check address validity with program info */
 578         *paddr = ((addr_t *)fp)[-1];
 579         return 0;
 580     }
 581 }
 582
 583 /* ------------------------------------------------------------- */
 584 #else
 585
 586 #warning add arch specific rt_get_caller_pc()
 587 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 588 {
 589     return -1;
 590 }
 591
 592 #endif /* !__i386__ */
 593
 594 /* ------------------------------------------------------------- */
 595 #else /* WIN32 */
 596
 597 static long __stdcall cpu_exception_handler(EXCEPTION_POINTERS *ex_info)
 598 {
 599     EXCEPTION_RECORD *er = ex_info->ExceptionRecord;
 600     CONTEXT *uc = ex_info->ContextRecord;
 601     switch (er->ExceptionCode) {
 602     case EXCEPTION_ACCESS_VIOLATION:
 603         if (rt_bound_error_msg && *rt_bound_error_msg)
 604             rt_error(uc, *rt_bound_error_msg);
 605         else
 606             rt_error(uc, "access violation");
 607         break;
 608     case EXCEPTION_STACK_OVERFLOW:
 609         rt_error(uc, "stack overflow");
 610         break;
 611     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 612         rt_error(uc, "division by zero");
 613         break;
 614     default:
 615         rt_error(uc, "exception caught");
 616         break;
 617     }
 618     return EXCEPTION_EXECUTE_HANDLER;
 619 }
 620
 621 /* Generate a stack backtrace when a CPU exception occurs. */
 622 static void set_exception_handler(void)
 623 {
 624     SetUnhandledExceptionFilter(cpu_exception_handler);
 625 }
 626
 627 #ifdef _WIN64
 628 static void win64_add_function_table(TCCState *s1)
 629 {
 630     RtlAddFunctionTable(
 631         (RUNTIME_FUNCTION*)s1->uw_pdata->sh_addr,
 632         s1->uw_pdata->data_offset / sizeof (RUNTIME_FUNCTION),
 633         text_section->sh_addr
 634         );
 635 }
 636 #endif
 637
 638 /* return the PC at frame level 'level'. Return non zero if not found */
 639 static int rt_get_caller_pc(addr_t *paddr, CONTEXT *uc, int level)
 640 {
 641     addr_t fp, pc;
 642     int i;
 643 #ifdef _WIN64
 644     pc = uc->Rip;
 645     fp = uc->Rbp;
 646 #else
 647     pc = uc->Eip;
 648     fp = uc->Ebp;
 649 #endif
 650     if (level > 0) {
 651         for(i=1;i<level;i++) {
 652             /* XXX: check address validity with program info */
 653             if (fp <= 0x1000 || fp >= 0xc0000000)
 654                 return -1;
 655             fp = ((addr_t*)fp)[0];
 656         }
 657         pc = ((addr_t*)fp)[1];
 658     }
 659     *paddr = pc;
 660     return 0;
 661 }
 662
 663 #endif /* _WIN32 */
 664 #endif /* CONFIG_TCC_BACKTRACE */
 665 /* ------------------------------------------------------------- */
 666
 667 #ifdef CONFIG_TCC_STATIC
 668
 669 #define RTLD_LAZY       0x001
 670 #define RTLD_NOW        0x002
 671 #define RTLD_GLOBAL     0x100
 672 #define RTLD_DEFAULT    NULL
 673
 674 /* dummy function for profiling */
 675 ST_FUNC void *dlopen(const char *filename, int flag)
 676 {
 677     return NULL;
 678 }
 679
 680 ST_FUNC void dlclose(void *p)
 681 {
 682 }
 683 /*
 684 const char *dlerror(void)
 685 {
 686     return "error";
 687 }
 688 */
 689 typedef struct TCCSyms {
 690     char *str;
 691     void *ptr;
 692 } TCCSyms;
 693
 694 #define TCCSYM(a) { #a, &a, },
 695
 696 /* add the symbol you want here if no dynamic linking is done */
 697 static TCCSyms tcc_syms[] = {
 698 #if !defined(CONFIG_TCCBOOT)
 699     TCCSYM(printf)
 700     TCCSYM(fprintf)
 701     TCCSYM(fopen)
 702     TCCSYM(fclose)
 703 #endif
 704     { NULL, NULL },
 705 };
 706
 707 ST_FUNC void *resolve_sym(TCCState *s1, const char *symbol)
 708 {
 709     TCCSyms *p;
 710     p = tcc_syms;
 711     while (p->str != NULL) {
 712         if (!strcmp(p->str, symbol))
 713             return p->ptr;
 714         p++;
 715     }
 716     return NULL;
 717 }
 718
 719 #elif !defined(_WIN32)
 720
 721 ST_FUNC void *resolve_sym(TCCState *s1, const char *sym)
 722 {
 723     return dlsym(RTLD_DEFAULT, sym);
 724 }
 725
 726 #endif /* CONFIG_TCC_STATIC */
 727 #endif /* TCC_IS_NATIVE */
 728 /* ------------------------------------------------------------- */