Subversion Repositories eco32

/*

 * except.c -- exception handling

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <setjmp.h>

#include "error.h"

#include "except.h"

#define MAX_ENV_NEST_DEPTH      10

static jmp_buf *environments[MAX_ENV_NEST_DEPTH];

static int currentEnvironment = -1;

void throwException(int exception) {

  if (currentEnvironment < 0) {

    error("exception %d thrown while no environment active", exception);

  }

  longjmp(*environments[currentEnvironment], exception);

}

void pushEnvironment(jmp_buf *environment) {

  if (currentEnvironment == MAX_ENV_NEST_DEPTH - 1) {

    error("too many environments active");

  }

  currentEnvironment++;

  environments[currentEnvironment] = environment;

}

void popEnvironment(void) {

  if (currentEnvironment < 0) {

    error("cannot pop environment - none active");

  }

  currentEnvironment--;

}

static char *cause[32] = {

  /*  0 */  "serial line 0 xmt interrupt",

  /*  1 */  "serial line 0 rcv interrupt",

  /*  2 */  "serial line 1 xmt interrupt",

  /*  3 */  "serial line 1 rcv interrupt",

  /*  4 */  "keyboard interrupt",

  /*  5 */  "unknown interrupt",

  /*  6 */  "unknown interrupt",

  /*  7 */  "unknown interrupt",

  /*  8 */  "disk interrupt",

  /*  9 */  "unknown interrupt",

  /* 10 */  "unknown interrupt",

  /* 11 */  "unknown interrupt",

  /* 12 */  "unknown interrupt",

  /* 13 */  "unknown interrupt",

  /* 14 */  "timer 0 interrupt",

  /* 15 */  "timer 1 interrupt",

  /* 16 */  "bus timeout exception",

  /* 17 */  "illegal instruction exception",

  /* 18 */  "privileged instruction exception",

  /* 19 */  "divide instruction exception",

  /* 20 */  "trap instruction exception",

  /* 21 */  "TLB miss exception",

  /* 22 */  "TLB write exception",

  /* 23 */  "TLB invalid exception",

  /* 24 */  "illegal address exception",

  /* 25 */  "privileged address exception",

  /* 26 */  "unknown exception",

  /* 27 */  "unknown exception",

  /* 28 */  "unknown exception",

  /* 29 */  "unknown exception",

  /* 30 */  "unknown exception",

  /* 31 */  "unknown exception"

};

char *exceptionToString(int exception) {

  if (exception < 0 ||

      exception >= sizeof(cause)/sizeof(cause[0])) {

    error("exception number out of bounds");

  }

  return cause[exception];

}