tccosposix.c

   1 /*
   2  *  Posix OS specific functions for TCC
   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 #include "tcc.h"
  21 #include <sys/ucontext.h>
  22
  23 #ifdef __i386__
  24 /* fix for glibc 2.1 */
  25 #ifndef REG_EIP
  26 #define REG_EIP EIP
  27 #define REG_EBP EBP
  28 #endif
  29
  30 /* return the PC at frame level 'level'. Return non zero if not found */
  31 static int rt_get_caller_pc(unsigned long *paddr,
  32                             ucontext_t *uc, int level)
  33 {
  34     unsigned long fp;
  35     int i;
  36
  37     if (level == 0) {
  38 #if defined(__FreeBSD__)
  39         *paddr = uc->uc_mcontext.mc_eip;
  40 #elif defined(__dietlibc__)
  41         *paddr = uc->uc_mcontext.eip;
  42 #else
  43         *paddr = uc->uc_mcontext.gregs[REG_EIP];
  44 #endif
  45         return 0;
  46     } else {
  47 #if defined(__FreeBSD__)
  48         fp = uc->uc_mcontext.mc_ebp;
  49 #elif defined(__dietlibc__)
  50         fp = uc->uc_mcontext.ebp;
  51 #else
  52         fp = uc->uc_mcontext.gregs[REG_EBP];
  53 #endif
  54         for(i=1;i<level;i++) {
  55             /* XXX: check address validity with program info */
  56             if (fp <= 0x1000 || fp >= 0xc0000000)
  57                 return -1;
  58             fp = ((unsigned long *)fp)[0];
  59         }
  60         *paddr = ((unsigned long *)fp)[1];
  61         return 0;
  62     }
  63 }
  64 #elif defined(__x86_64__)
  65 /* return the PC at frame level 'level'. Return non zero if not found */
  66 static int rt_get_caller_pc(unsigned long *paddr,
  67                             ucontext_t *uc, int level)
  68 {
  69     unsigned long fp;
  70     int i;
  71
  72     if (level == 0) {
  73         /* XXX: only support linux */
  74 #if defined(__FreeBSD__)
  75         *paddr = uc->uc_mcontext.mc_rip;
  76 #else
  77         *paddr = uc->uc_mcontext.gregs[REG_RIP];
  78 #endif
  79         return 0;
  80     } else {
  81 #if defined(__FreeBSD__)
  82         fp = uc->uc_mcontext.mc_rbp;
  83 #else
  84         fp = uc->uc_mcontext.gregs[REG_RBP];
  85 #endif
  86         for(i=1;i<level;i++) {
  87             /* XXX: check address validity with program info */
  88             if (fp <= 0x1000)
  89                 return -1;
  90             fp = ((unsigned long *)fp)[0];
  91         }
  92         *paddr = ((unsigned long *)fp)[1];
  93         return 0;
  94     }
  95 }
  96 #else
  97 #warning add arch specific rt_get_caller_pc()
  98 static int rt_get_caller_pc(unsigned long *paddr,
  99                             ucontext_t *uc, int level)
 100 {
 101     return -1;
 102 }
 103 #endif
 104
 105
 106
 107 /* emit a run time error at position 'pc' */
 108 void rt_error(ucontext_t *uc, const char *fmt, ...)
 109 {
 110     va_list ap;
 111     unsigned long pc;
 112     int i;
 113
 114     va_start(ap, fmt);
 115     fprintf(stderr, "Runtime error: ");
 116     vfprintf(stderr, fmt, ap);
 117     fprintf(stderr, "\n");
 118     for(i=0;i<num_callers;i++) {
 119         if (rt_get_caller_pc(&pc, uc, i) < 0)
 120             break;
 121         if (i == 0)
 122             fprintf(stderr, "at ");
 123         else
 124             fprintf(stderr, "by ");
 125         pc = rt_printline(pc);
 126         if (pc == rt_prog_main && pc)
 127             break;
 128     }
 129     exit(255);
 130     va_end(ap);
 131 }
 132
 133 /* signal handler for fatal errors */
 134 static void sig_error(int signum, siginfo_t *siginf, void *puc)
 135 {
 136     ucontext_t *uc = puc;
 137
 138     switch(signum) {
 139     case SIGFPE:
 140         switch(siginf->si_code) {
 141         case FPE_INTDIV:
 142         case FPE_FLTDIV:
 143             rt_error(uc, "division by zero");
 144             break;
 145         default:
 146             rt_error(uc, "floating point exception");
 147             break;
 148         }
 149         break;
 150     case SIGBUS:
 151     case SIGSEGV:
 152         if (rt_bound_error_msg && *rt_bound_error_msg)
 153             rt_error(uc, *rt_bound_error_msg);
 154         else
 155             rt_error(uc, "dereferencing invalid pointer");
 156         break;
 157     case SIGILL:
 158         rt_error(uc, "illegal instruction");
 159         break;
 160     case SIGABRT:
 161         rt_error(uc, "abort() called");
 162         break;
 163     default:
 164         rt_error(uc, "caught signal %d", signum);
 165         break;
 166     }
 167     exit(255);
 168 }
 169
 170 /* Generate a stack backtrace when a CPU exception occurs. */
 171 void handle_cpu_exception(void)
 172 {
 173     struct sigaction sigact;
 174     /* install TCC signal handlers to print debug info on fatal
 175        runtime errors */
 176     sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
 177     sigact.sa_sigaction = sig_error;
 178     sigemptyset(&sigact.sa_mask);
 179     sigaction(SIGFPE, &sigact, NULL);
 180     sigaction(SIGILL, &sigact, NULL);
 181     sigaction(SIGSEGV, &sigact, NULL);
 182     sigaction(SIGBUS, &sigact, NULL);
 183     sigaction(SIGABRT, &sigact, NULL);
 184 }