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 #ifndef _WIN32
  27 # include <sys/mman.h>
  28 #endif
  29
  30 #ifdef CONFIG_TCC_BACKTRACE
  31 # ifndef _WIN32
  32 #  include <signal.h>
  33 #  ifndef __OpenBSD__
  34 #   include <sys/ucontext.h>
  35 #  endif
  36 # else
  37 #  define ucontext_t CONTEXT
  38 # endif
  39 ST_DATA int rt_num_callers = 6;
  40 ST_DATA const char **rt_bound_error_msg;
  41 ST_DATA void *rt_prog_main;
  42 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level);
  43 static void rt_error(ucontext_t *uc, const char *fmt, ...);
  44 static void set_exception_handler(void);
  45 #endif
  46
  47 static void set_pages_executable(void *ptr, unsigned long length);
  48 static int tcc_relocate_ex(TCCState *s1, void *ptr);
  49
  50 #ifdef _WIN64
  51 static void *win64_add_function_table(TCCState *s1);
  52 static void win64_del_function_table(void *);
  53 #endif
  54
  55 // #define HAVE_SELINUX
  56
  57 /* ------------------------------------------------------------- */
  58 /* Do all relocations (needed before using tcc_get_symbol())
  59    Returns -1 on error. */
  60
  61 LIBTCCAPI int tcc_relocate(TCCState *s1, void *ptr)
  62 {
  63     int size;  void *mem;
  64
  65     if (TCC_RELOCATE_AUTO != ptr)
  66         return tcc_relocate_ex(s1, ptr);
  67
  68     size = tcc_relocate_ex(s1, NULL);
  69     if (size < 0)
  70         return -1;
  71
  72 #ifdef HAVE_SELINUX
  73     {   /* Use mmap instead of malloc for Selinux.  Ref:
  74            http://www.gnu.org/s/libc/manual/html_node/File-Size.html */
  75
  76         char tmpfname[] = "/tmp/.tccrunXXXXXX";
  77         int fd = mkstemp (tmpfname);
  78         void *wr_mem;
  79
  80         unlink (tmpfname);
  81         ftruncate (fd, size);
  82
  83         wr_mem = mmap (NULL, size, PROT_READ|PROT_WRITE,
  84             MAP_SHARED, fd, 0);
  85         if (wr_mem == MAP_FAILED)
  86             tcc_error("/tmp not writeable");
  87         mem = mmap (NULL, size, PROT_READ|PROT_EXEC,
  88             MAP_SHARED, fd, 0);
  89         if (mem == MAP_FAILED)
  90             tcc_error("/tmp not executable");
  91
  92         tcc_relocate_ex(s1, wr_mem);
  93         dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, (void*)(addr_t)size);
  94         dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, wr_mem);
  95         dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, mem);
  96     }
  97 #else
  98     mem = tcc_malloc(size);
  99     tcc_relocate_ex(s1, mem); /* no more errors expected */
 100     dynarray_add(&s1->runtime_mem, &s1->nb_runtime_mem, mem);
 101 #endif
 102     return 0;
 103 }
 104
 105 ST_FUNC void tcc_run_free(TCCState *s1)
 106 {
 107     int i;
 108
 109     for (i = 0; i < s1->nb_runtime_mem; ++i) {
 110 #ifdef HAVE_SELINUX
 111         int size = (int)(addr_t)s1->runtime_mem[i];
 112         munmap(s1->runtime_mem[++i], size);
 113         munmap(s1->runtime_mem[++i], size);
 114 #else
 115 # ifdef _WIN64
 116         win64_del_function_table(*(void**)s1->runtime_mem[i]);
 117 # endif
 118         tcc_free(s1->runtime_mem[i]);
 119 #endif
 120     }
 121     tcc_free(s1->runtime_mem);
 122 }
 123
 124 /* launch the compiled program with the given arguments */
 125 LIBTCCAPI int tcc_run(TCCState *s1, int argc, char **argv)
 126 {
 127     int (*prog_main)(int, char **);
 128
 129     if (tcc_relocate(s1, TCC_RELOCATE_AUTO) < 0)
 130         return -1;
 131     prog_main = tcc_get_symbol_err(s1, s1->runtime_main);
 132
 133 #ifdef CONFIG_TCC_BACKTRACE
 134     if (s1->do_debug) {
 135         set_exception_handler();
 136         rt_prog_main = prog_main;
 137     }
 138 #endif
 139
 140     errno = 0; /* clean errno value */
 141
 142 #ifdef CONFIG_TCC_BCHECK
 143     if (s1->do_bounds_check) {
 144         void (*bound_init)(void);
 145         void (*bound_exit)(void);
 146         void (*bound_new_region)(void *p, addr_t size);
 147         int  (*bound_delete_region)(void *p);
 148         int i, ret;
 149
 150         /* set error function */
 151         rt_bound_error_msg = tcc_get_symbol_err(s1, "__bound_error_msg");
 152         /* XXX: use .init section so that it also work in binary ? */
 153         bound_init = tcc_get_symbol_err(s1, "__bound_init");
 154         bound_exit = tcc_get_symbol_err(s1, "__bound_exit");
 155         bound_new_region = tcc_get_symbol_err(s1, "__bound_new_region");
 156         bound_delete_region = tcc_get_symbol_err(s1, "__bound_delete_region");
 157
 158         bound_init();
 159         /* mark argv area as valid */
 160         bound_new_region(argv, argc*sizeof(argv[0]));
 161         for (i=0; i<argc; ++i)
 162             bound_new_region(argv[i], strlen(argv[i]) + 1);
 163
 164         ret = (*prog_main)(argc, argv);
 165
 166         /* unmark argv area */
 167         for (i=0; i<argc; ++i)
 168             bound_delete_region(argv[i]);
 169         bound_delete_region(argv);
 170         bound_exit();
 171         return ret;
 172     }
 173 #endif
 174     return (*prog_main)(argc, argv);
 175 }
 176
 177 /* relocate code. Return -1 on error, required size if ptr is NULL,
 178    otherwise copy code into buffer passed by the caller */
 179 static int tcc_relocate_ex(TCCState *s1, void *ptr)
 180 {
 181     Section *s;
 182     unsigned long offset, length;
 183     addr_t mem;
 184     int i;
 185
 186     if (NULL == ptr) {
 187         s1->nb_errors = 0;
 188 #ifdef TCC_TARGET_PE
 189         pe_output_file(s1, NULL);
 190 #else
 191         tcc_add_runtime(s1);
 192         relocate_common_syms();
 193         tcc_add_linker_symbols(s1);
 194         build_got_entries(s1);
 195 #endif
 196         if (s1->nb_errors)
 197             return -1;
 198     }
 199
 200     offset = 0, mem = (addr_t)ptr;
 201 #ifdef _WIN64
 202     offset += sizeof (void*);
 203 #endif
 204     for(i = 1; i < s1->nb_sections; i++) {
 205         s = s1->sections[i];
 206         if (0 == (s->sh_flags & SHF_ALLOC))
 207             continue;
 208         offset = (offset + 15) & ~15;
 209         s->sh_addr = mem ? mem + offset : 0;
 210         offset += s->data_offset;
 211     }
 212
 213     /* relocate symbols */
 214     relocate_syms(s1, s1->symtab, 1);
 215     if (s1->nb_errors)
 216         return -1;
 217
 218     if (0 == mem)
 219         return offset;
 220
 221     /* relocate each section */
 222     for(i = 1; i < s1->nb_sections; i++) {
 223         s = s1->sections[i];
 224         if (s->reloc)
 225             relocate_section(s1, s);
 226     }
 227     relocate_plt(s1);
 228
 229 #ifdef _WIN64
 230     *(void**)ptr = win64_add_function_table(s1);
 231 #endif
 232
 233     for(i = 1; i < s1->nb_sections; i++) {
 234         s = s1->sections[i];
 235         if (0 == (s->sh_flags & SHF_ALLOC))
 236             continue;
 237         length = s->data_offset;
 238         // printf("%-12s %08lx %04x\n", s->name, s->sh_addr, length);
 239         ptr = (void*)s->sh_addr;
 240         if (NULL == s->data || s->sh_type == SHT_NOBITS)
 241             memset(ptr, 0, length);
 242         else
 243             memcpy(ptr, s->data, length);
 244         /* mark executable sections as executable in memory */
 245         if (s->sh_flags & SHF_EXECINSTR)
 246             set_pages_executable(ptr, length);
 247     }
 248     return 0;
 249 }
 250
 251 /* ------------------------------------------------------------- */
 252 /* allow to run code in memory */
 253
 254 static void set_pages_executable(void *ptr, unsigned long length)
 255 {
 256 #ifdef _WIN32
 257     unsigned long old_protect;
 258     VirtualProtect(ptr, length, PAGE_EXECUTE_READWRITE, &old_protect);
 259 #else
 260 #ifndef PAGESIZE
 261 # define PAGESIZE 4096
 262 #endif
 263     addr_t start, end;
 264     start = (addr_t)ptr & ~(PAGESIZE - 1);
 265     end = (addr_t)ptr + length;
 266     end = (end + PAGESIZE - 1) & ~(PAGESIZE - 1);
 267     if (mprotect((void *)start, end - start, PROT_READ | PROT_WRITE | PROT_EXEC))
 268         tcc_error("mprotect failed: did you mean to configure --with-selinux?");
 269 #if defined TCC_TARGET_ARM || defined TCC_TARGET_ARM64
 270     { extern void __clear_cache(void *beginning, void *end);
 271       __clear_cache(ptr, (char *)ptr + length); }
 272 #endif
 273 #endif
 274 }
 275
 276 #ifdef _WIN64
 277 static void *win64_add_function_table(TCCState *s1)
 278 {
 279     void *p = NULL;
 280     if (s1->uw_pdata) {
 281         p = (void*)s1->uw_pdata->sh_addr;
 282         RtlAddFunctionTable(
 283             (RUNTIME_FUNCTION*)p,
 284             s1->uw_pdata->data_offset / sizeof (RUNTIME_FUNCTION),
 285             text_section->sh_addr
 286             );
 287         s1->uw_pdata = NULL;
 288     }
 289     return p;;
 290 }
 291
 292 static void win64_del_function_table(void *p)
 293 {
 294     if (p) {
 295         RtlDeleteFunctionTable((RUNTIME_FUNCTION*)p);
 296     }
 297 }
 298 #endif
 299
 300 /* ------------------------------------------------------------- */
 301 #ifdef CONFIG_TCC_BACKTRACE
 302
 303 ST_FUNC void tcc_set_num_callers(int n)
 304 {
 305     rt_num_callers = n;
 306 }
 307
 308 /* print the position in the source file of PC value 'pc' by reading
 309    the stabs debug information */
 310 static addr_t rt_printline(addr_t wanted_pc, const char *msg)
 311 {
 312     char func_name[128], last_func_name[128];
 313     addr_t func_addr, last_pc, pc;
 314     const char *incl_files[INCLUDE_STACK_SIZE];
 315     int incl_index, len, last_line_num, i;
 316     const char *str, *p;
 317
 318     Stab_Sym *stab_sym = NULL, *stab_sym_end, *sym;
 319     int stab_len = 0;
 320     char *stab_str = NULL;
 321
 322     if (stab_section) {
 323         stab_len = stab_section->data_offset;
 324         stab_sym = (Stab_Sym *)stab_section->data;
 325         stab_str = (char *) stabstr_section->data;
 326     }
 327
 328     func_name[0] = '\0';
 329     func_addr = 0;
 330     incl_index = 0;
 331     last_func_name[0] = '\0';
 332     last_pc = (addr_t)-1;
 333     last_line_num = 1;
 334
 335     if (!stab_sym)
 336         goto no_stabs;
 337
 338     stab_sym_end = (Stab_Sym*)((char*)stab_sym + stab_len);
 339     for (sym = stab_sym + 1; sym < stab_sym_end; ++sym) {
 340         switch(sym->n_type) {
 341             /* function start or end */
 342         case N_FUN:
 343             if (sym->n_strx == 0) {
 344                 /* we test if between last line and end of function */
 345                 pc = sym->n_value + func_addr;
 346                 if (wanted_pc >= last_pc && wanted_pc < pc)
 347                     goto found;
 348                 func_name[0] = '\0';
 349                 func_addr = 0;
 350             } else {
 351                 str = stab_str + sym->n_strx;
 352                 p = strchr(str, ':');
 353                 if (!p) {
 354                     pstrcpy(func_name, sizeof(func_name), str);
 355                 } else {
 356                     len = p - str;
 357                     if (len > sizeof(func_name) - 1)
 358                         len = sizeof(func_name) - 1;
 359                     memcpy(func_name, str, len);
 360                     func_name[len] = '\0';
 361                 }
 362                 func_addr = sym->n_value;
 363             }
 364             break;
 365             /* line number info */
 366         case N_SLINE:
 367             pc = sym->n_value + func_addr;
 368             if (wanted_pc >= last_pc && wanted_pc < pc)
 369                 goto found;
 370             last_pc = pc;
 371             last_line_num = sym->n_desc;
 372             /* XXX: slow! */
 373             strcpy(last_func_name, func_name);
 374             break;
 375             /* include files */
 376         case N_BINCL:
 377             str = stab_str + sym->n_strx;
 378         add_incl:
 379             if (incl_index < INCLUDE_STACK_SIZE) {
 380                 incl_files[incl_index++] = str;
 381             }
 382             break;
 383         case N_EINCL:
 384             if (incl_index > 1)
 385                 incl_index--;
 386             break;
 387         case N_SO:
 388             if (sym->n_strx == 0) {
 389                 incl_index = 0; /* end of translation unit */
 390             } else {
 391                 str = stab_str + sym->n_strx;
 392                 /* do not add path */
 393                 len = strlen(str);
 394                 if (len > 0 && str[len - 1] != '/')
 395                     goto add_incl;
 396             }
 397             break;
 398         }
 399     }
 400
 401 no_stabs:
 402     /* second pass: we try symtab symbols (no line number info) */
 403     incl_index = 0;
 404     if (symtab_section)
 405     {
 406         ElfW(Sym) *sym, *sym_end;
 407         int type;
 408
 409         sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
 410         for(sym = (ElfW(Sym) *)symtab_section->data + 1;
 411             sym < sym_end;
 412             sym++) {
 413             type = ELFW(ST_TYPE)(sym->st_info);
 414             if (type == STT_FUNC || type == STT_GNU_IFUNC) {
 415                 if (wanted_pc >= sym->st_value &&
 416                     wanted_pc < sym->st_value + sym->st_size) {
 417                     pstrcpy(last_func_name, sizeof(last_func_name),
 418                             (char *) strtab_section->data + sym->st_name);
 419                     func_addr = sym->st_value;
 420                     goto found;
 421                 }
 422             }
 423         }
 424     }
 425     /* did not find any info: */
 426     fprintf(stderr, "%s %p ???\n", msg, (void*)wanted_pc);
 427     fflush(stderr);
 428     return 0;
 429  found:
 430     i = incl_index;
 431     if (i > 0)
 432         fprintf(stderr, "%s:%d: ", incl_files[--i], last_line_num);
 433     fprintf(stderr, "%s %p", msg, (void*)wanted_pc);
 434     if (last_func_name[0] != '\0')
 435         fprintf(stderr, " %s()", last_func_name);
 436     if (--i >= 0) {
 437         fprintf(stderr, " (included from ");
 438         for (;;) {
 439             fprintf(stderr, "%s", incl_files[i]);
 440             if (--i < 0)
 441                 break;
 442             fprintf(stderr, ", ");
 443         }
 444         fprintf(stderr, ")");
 445     }
 446     fprintf(stderr, "\n");
 447     fflush(stderr);
 448     return func_addr;
 449 }
 450
 451 /* emit a run time error at position 'pc' */
 452 static void rt_error(ucontext_t *uc, const char *fmt, ...)
 453 {
 454     va_list ap;
 455     addr_t pc;
 456     int i;
 457
 458     fprintf(stderr, "Runtime error: ");
 459     va_start(ap, fmt);
 460     vfprintf(stderr, fmt, ap);
 461     va_end(ap);
 462     fprintf(stderr, "\n");
 463
 464     for(i=0;i<rt_num_callers;i++) {
 465         if (rt_get_caller_pc(&pc, uc, i) < 0)
 466             break;
 467         pc = rt_printline(pc, i ? "by" : "at");
 468         if (pc == (addr_t)rt_prog_main && pc)
 469             break;
 470     }
 471 }
 472
 473 /* ------------------------------------------------------------- */
 474 #ifndef _WIN32
 475
 476 /* signal handler for fatal errors */
 477 static void sig_error(int signum, siginfo_t *siginf, void *puc)
 478 {
 479     ucontext_t *uc = puc;
 480
 481     switch(signum) {
 482     case SIGFPE:
 483         switch(siginf->si_code) {
 484         case FPE_INTDIV:
 485         case FPE_FLTDIV:
 486             rt_error(uc, "division by zero");
 487             break;
 488         default:
 489             rt_error(uc, "floating point exception");
 490             break;
 491         }
 492         break;
 493     case SIGBUS:
 494     case SIGSEGV:
 495         if (rt_bound_error_msg && *rt_bound_error_msg)
 496             rt_error(uc, *rt_bound_error_msg);
 497         else
 498             rt_error(uc, "dereferencing invalid pointer");
 499         break;
 500     case SIGILL:
 501         rt_error(uc, "illegal instruction");
 502         break;
 503     case SIGABRT:
 504         rt_error(uc, "abort() called");
 505         break;
 506     default:
 507         rt_error(uc, "caught signal %d", signum);
 508         break;
 509     }
 510     exit(255);
 511 }
 512
 513 #ifndef SA_SIGINFO
 514 # define SA_SIGINFO 0x00000004u
 515 #endif
 516
 517 /* Generate a stack backtrace when a CPU exception occurs. */
 518 static void set_exception_handler(void)
 519 {
 520     struct sigaction sigact;
 521     /* install TCC signal handlers to print debug info on fatal
 522        runtime errors */
 523     sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
 524     sigact.sa_sigaction = sig_error;
 525     sigemptyset(&sigact.sa_mask);
 526     sigaction(SIGFPE, &sigact, NULL);
 527     sigaction(SIGILL, &sigact, NULL);
 528     sigaction(SIGSEGV, &sigact, NULL);
 529     sigaction(SIGBUS, &sigact, NULL);
 530     sigaction(SIGABRT, &sigact, NULL);
 531 }
 532
 533 /* ------------------------------------------------------------- */
 534 #ifdef __i386__
 535
 536 /* fix for glibc 2.1 */
 537 #ifndef REG_EIP
 538 #define REG_EIP EIP
 539 #define REG_EBP EBP
 540 #endif
 541
 542 /* return the PC at frame level 'level'. Return negative if not found */
 543 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 544 {
 545     addr_t fp;
 546     int i;
 547
 548     if (level == 0) {
 549 #if defined(__APPLE__)
 550         *paddr = uc->uc_mcontext->__ss.__eip;
 551 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 552         *paddr = uc->uc_mcontext.mc_eip;
 553 #elif defined(__dietlibc__)
 554         *paddr = uc->uc_mcontext.eip;
 555 #elif defined(__NetBSD__)
 556         *paddr = uc->uc_mcontext.__gregs[_REG_EIP];
 557 #elif defined(__OpenBSD__)
 558         *paddr = uc->sc_eip;
 559 #else
 560         *paddr = uc->uc_mcontext.gregs[REG_EIP];
 561 #endif
 562         return 0;
 563     } else {
 564 #if defined(__APPLE__)
 565         fp = uc->uc_mcontext->__ss.__ebp;
 566 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 567         fp = uc->uc_mcontext.mc_ebp;
 568 #elif defined(__dietlibc__)
 569         fp = uc->uc_mcontext.ebp;
 570 #elif defined(__NetBSD__)
 571         fp = uc->uc_mcontext.__gregs[_REG_EBP];
 572 #elif defined(__OpenBSD__)
 573         *paddr = uc->sc_ebp;
 574 #else
 575         fp = uc->uc_mcontext.gregs[REG_EBP];
 576 #endif
 577         for(i=1;i<level;i++) {
 578             /* XXX: check address validity with program info */
 579             if (fp <= 0x1000 || fp >= 0xc0000000)
 580                 return -1;
 581             fp = ((addr_t *)fp)[0];
 582         }
 583         *paddr = ((addr_t *)fp)[1];
 584         return 0;
 585     }
 586 }
 587
 588 /* ------------------------------------------------------------- */
 589 #elif defined(__x86_64__)
 590
 591 /* return the PC at frame level 'level'. Return negative if not found */
 592 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 593 {
 594     addr_t fp;
 595     int i;
 596
 597     if (level == 0) {
 598         /* XXX: only support linux */
 599 #if defined(__APPLE__)
 600         *paddr = uc->uc_mcontext->__ss.__rip;
 601 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 602         *paddr = uc->uc_mcontext.mc_rip;
 603 #elif defined(__NetBSD__)
 604         *paddr = uc->uc_mcontext.__gregs[_REG_RIP];
 605 #else
 606         *paddr = uc->uc_mcontext.gregs[REG_RIP];
 607 #endif
 608         return 0;
 609     } else {
 610 #if defined(__APPLE__)
 611         fp = uc->uc_mcontext->__ss.__rbp;
 612 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 613         fp = uc->uc_mcontext.mc_rbp;
 614 #elif defined(__NetBSD__)
 615         fp = uc->uc_mcontext.__gregs[_REG_RBP];
 616 #else
 617         fp = uc->uc_mcontext.gregs[REG_RBP];
 618 #endif
 619         for(i=1;i<level;i++) {
 620             /* XXX: check address validity with program info */
 621             if (fp <= 0x1000)
 622                 return -1;
 623             fp = ((addr_t *)fp)[0];
 624         }
 625         *paddr = ((addr_t *)fp)[1];
 626         return 0;
 627     }
 628 }
 629
 630 /* ------------------------------------------------------------- */
 631 #elif defined(__arm__)
 632
 633 /* return the PC at frame level 'level'. Return negative if not found */
 634 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 635 {
 636     addr_t fp, sp;
 637     int i;
 638
 639     if (level == 0) {
 640         /* XXX: only supports linux */
 641 #if defined(__linux__)
 642         *paddr = uc->uc_mcontext.arm_pc;
 643 #else
 644         return -1;
 645 #endif
 646         return 0;
 647     } else {
 648 #if defined(__linux__)
 649         fp = uc->uc_mcontext.arm_fp;
 650         sp = uc->uc_mcontext.arm_sp;
 651         if (sp < 0x1000)
 652             sp = 0x1000;
 653 #else
 654         return -1;
 655 #endif
 656         /* XXX: specific to tinycc stack frames */
 657         if (fp < sp + 12 || fp & 3)
 658             return -1;
 659         for(i = 1; i < level; i++) {
 660             sp = ((addr_t *)fp)[-2];
 661             if (sp < fp || sp - fp > 16 || sp & 3)
 662                 return -1;
 663             fp = ((addr_t *)fp)[-3];
 664             if (fp <= sp || fp - sp < 12 || fp & 3)
 665                 return -1;
 666         }
 667         /* XXX: check address validity with program info */
 668         *paddr = ((addr_t *)fp)[-1];
 669         return 0;
 670     }
 671 }
 672
 673 /* ------------------------------------------------------------- */
 674 #elif defined(__aarch64__)
 675
 676 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 677 {
 678     if (level < 0)
 679         return -1;
 680     else if (level == 0) {
 681         *paddr = uc->uc_mcontext.pc;
 682         return 0;
 683     }
 684     else {
 685         addr_t *fp = (addr_t *)uc->uc_mcontext.regs[29];
 686         int i;
 687         for (i = 1; i < level; i++)
 688             fp = (addr_t *)fp[0];
 689         *paddr = fp[1];
 690         return 0;
 691     }
 692 }
 693
 694 /* ------------------------------------------------------------- */
 695 #else
 696
 697 #warning add arch specific rt_get_caller_pc()
 698 static int rt_get_caller_pc(addr_t *paddr, ucontext_t *uc, int level)
 699 {
 700     return -1;
 701 }
 702
 703 #endif /* !__i386__ */
 704
 705 /* ------------------------------------------------------------- */
 706 #else /* WIN32 */
 707
 708 static long __stdcall cpu_exception_handler(EXCEPTION_POINTERS *ex_info)
 709 {
 710     EXCEPTION_RECORD *er = ex_info->ExceptionRecord;
 711     CONTEXT *uc = ex_info->ContextRecord;
 712     switch (er->ExceptionCode) {
 713     case EXCEPTION_ACCESS_VIOLATION:
 714         if (rt_bound_error_msg && *rt_bound_error_msg)
 715             rt_error(uc, *rt_bound_error_msg);
 716         else
 717             rt_error(uc, "access violation");
 718         break;
 719     case EXCEPTION_STACK_OVERFLOW:
 720         rt_error(uc, "stack overflow");
 721         break;
 722     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 723         rt_error(uc, "division by zero");
 724         break;
 725     default:
 726         rt_error(uc, "exception caught");
 727         break;
 728     }
 729     return EXCEPTION_EXECUTE_HANDLER;
 730 }
 731
 732 /* Generate a stack backtrace when a CPU exception occurs. */
 733 static void set_exception_handler(void)
 734 {
 735     SetUnhandledExceptionFilter(cpu_exception_handler);
 736 }
 737
 738 /* return the PC at frame level 'level'. Return non zero if not found */
 739 static int rt_get_caller_pc(addr_t *paddr, CONTEXT *uc, int level)
 740 {
 741     addr_t fp, pc;
 742     int i;
 743 #ifdef _WIN64
 744     pc = uc->Rip;
 745     fp = uc->Rbp;
 746 #else
 747     pc = uc->Eip;
 748     fp = uc->Ebp;
 749 #endif
 750     if (level > 0) {
 751         for(i=1;i<level;i++) {
 752             /* XXX: check address validity with program info */
 753             if (fp <= 0x1000 || fp >= 0xc0000000)
 754                 return -1;
 755             fp = ((addr_t*)fp)[0];
 756         }
 757         pc = ((addr_t*)fp)[1];
 758     }
 759     *paddr = pc;
 760     return 0;
 761 }
 762
 763 #endif /* _WIN32 */
 764 #endif /* CONFIG_TCC_BACKTRACE */
 765 /* ------------------------------------------------------------- */
 766 #ifdef CONFIG_TCC_STATIC
 767
 768 /* dummy function for profiling */
 769 ST_FUNC void *dlopen(const char *filename, int flag)
 770 {
 771     return NULL;
 772 }
 773
 774 ST_FUNC void dlclose(void *p)
 775 {
 776 }
 777
 778 ST_FUNC const char *dlerror(void)
 779 {
 780     return "error";
 781 }
 782
 783 typedef struct TCCSyms {
 784     char *str;
 785     void *ptr;
 786 } TCCSyms;
 787
 788
 789 /* add the symbol you want here if no dynamic linking is done */
 790 static TCCSyms tcc_syms[] = {
 791 #if !defined(CONFIG_TCCBOOT)
 792 #define TCCSYM(a) { #a, &a, },
 793     TCCSYM(printf)
 794     TCCSYM(fprintf)
 795     TCCSYM(fopen)
 796     TCCSYM(fclose)
 797 #undef TCCSYM
 798 #endif
 799     { NULL, NULL },
 800 };
 801
 802 ST_FUNC void *dlsym(void *handle, const char *symbol)
 803 {
 804     TCCSyms *p;
 805     p = tcc_syms;
 806     while (p->str != NULL) {
 807         if (!strcmp(p->str, symbol))
 808             return p->ptr;
 809         p++;
 810     }
 811     return NULL;
 812 }
 813
 814 #endif /* CONFIG_TCC_STATIC */
 815 #endif /* TCC_IS_NATIVE */
 816 /* ------------------------------------------------------------- */