error.c

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/**********************************************************************

  error.c -

  $Author: matz $
  $Date: 2005/07/20 01:09:53 $
  created at: Mon Aug  9 16:11:34 JST 1993

  Copyright (C) 1993-2003 Yukihiro Matsumoto

**********************************************************************/

#include "ruby.h"
#include "env.h"
#include "st.h"

#include <stdio.h>
#ifdef HAVE_STDARG_PROTOTYPES
#include <stdarg.h>
#define va_init_list(a,b) va_start(a,b)
#else
#include <varargs.h>
#define va_init_list(a,b) va_start(a)
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif

extern const char ruby_version[], ruby_release_date[], ruby_platform[];

int ruby_nerrs;

static int
err_position(buf, len)
    char *buf;
    long len;
{
    ruby_set_current_source();
    if (!ruby_sourcefile) {
        return 0;
    }
    else if (ruby_sourceline == 0) {
        return snprintf(buf, len, "%s: ", ruby_sourcefile);
    }
    else {
        return snprintf(buf, len, "%s:%d: ", ruby_sourcefile, ruby_sourceline);
    }
}

static void
err_snprintf(buf, len, fmt, args)
    char *buf;
    long len;
    const char *fmt;
    va_list args;
{
    long n;

    n = err_position(buf, len);
    if (len > n) {
        vsnprintf((char*)buf+n, len-n, fmt, args);
    }
}

static void err_append (const char*);
static void
err_print(fmt, args)
    const char *fmt;
    va_list args;
{
    char buf[BUFSIZ];

    err_snprintf(buf, BUFSIZ, fmt, args);
    err_append(buf);
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_compile_error(const char *fmt, ...)
#else
rb_compile_error(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    va_list args;

    va_init_list(args, fmt);
    err_print(fmt, args);
    va_end(args);
    ruby_nerrs++;
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_compile_error_append(const char *fmt, ...)
#else
rb_compile_error_append(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    va_list args;
    char buf[BUFSIZ];

    va_init_list(args, fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    va_end(args);
    err_append(buf);
}

static void
warn_print(fmt, args)
    const char *fmt;
    va_list args;
{
    char buf[BUFSIZ];
    int len;

    err_snprintf(buf, BUFSIZ, fmt, args);
    len = strlen(buf);
    buf[len++] = '\n';
    rb_write_error2(buf, len);
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_warn(const char *fmt, ...)
#else
rb_warn(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    char buf[BUFSIZ];
    va_list args;

    if (NIL_P(ruby_verbose)) return;

    snprintf(buf, BUFSIZ, "warning: %s", fmt);

    va_init_list(args, fmt);
    warn_print(buf, args);
    va_end(args);
}

/* rb_warning() reports only in verbose mode */
void
#ifdef HAVE_STDARG_PROTOTYPES
rb_warning(const char *fmt, ...)
#else
rb_warning(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    char buf[BUFSIZ];
    va_list args;

    if (!RTEST(ruby_verbose)) return;

    snprintf(buf, BUFSIZ, "warning: %s", fmt);

    va_init_list(args, fmt);
    warn_print(buf, args);
    va_end(args);
}

/*
 * call-seq:
 *    warn(msg)   => nil
 *
 * Display the given message (followed by a newline) on STDERR unless
 * warnings are disabled (for example with the <code>-W0</code> flag).
 */

static VALUE
rb_warn_m(self, mesg)
    VALUE self, mesg;
{
    if (!NIL_P(ruby_verbose)) {
        rb_io_write(rb_stderr, mesg);
        rb_io_write(rb_stderr, rb_default_rs);
    }
    return Qnil;
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_bug(const char *fmt, ...)
#else
rb_bug(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    char buf[BUFSIZ];
    va_list args;
    FILE *out = stderr;
    int len = err_position(buf, BUFSIZ);

    if (fwrite(buf, 1, len, out) == len ||
        fwrite(buf, 1, len, (out = stdout)) == len) {
        fputs("[BUG] ", out);
        va_init_list(args, fmt);
        vfprintf(out, fmt, args);
        va_end(args);
        fprintf(out, "\nruby %s (%s) [%s]\n\n",
                ruby_version, ruby_release_date, ruby_platform);
    }
    abort();
}

static struct types {
    int type;
    const char *name;
} builtin_types[] = {
    {T_NIL,     "nil"},
    {T_OBJECT,  "Object"},
    {T_CLASS,   "Class"},
    {T_ICLASS,  "iClass"},      /* internal use: mixed-in module holder */
    {T_MODULE,  "Module"},
    {T_FLOAT,   "Float"},
    {T_STRING,  "String"},
    {T_REGEXP,  "Regexp"},
    {T_ARRAY,   "Array"},
    {T_FIXNUM,  "Fixnum"},
    {T_HASH,    "Hash"},
    {T_STRUCT,  "Struct"},
    {T_BIGNUM,  "Bignum"},
    {T_FILE,    "File"},
    {T_TRUE,    "true"},
    {T_FALSE,   "false"},
    {T_SYMBOL,  "Symbol"},      /* :symbol */
    {T_DATA,    "Data"},        /* internal use: wrapped C pointers */
    {T_MATCH,   "MatchData"},   /* data of $~ */
    {T_VARMAP,  "Varmap"},      /* internal use: dynamic variables */
    {T_SCOPE,   "Scope"},       /* internal use: variable scope */
    {T_NODE,    "Node"},        /* internal use: syntax tree node */
    {T_UNDEF,   "undef"},       /* internal use: #undef; should not happen */
    {-1,        0}
};

void
rb_check_type(x, t)
    VALUE x;
    int t;
{
    struct types *type = builtin_types;

    if (x == Qundef) {
        rb_bug("undef leaked to the Ruby space");
    }

    if (TYPE(x) != t) {
        while (type->type >= 0) {
            if (type->type == t) {
                char *etype;

                if (NIL_P(x)) {
                    etype = "nil";
                }
                else if (FIXNUM_P(x)) {
                    etype = "Fixnum";
                }
                else if (SYMBOL_P(x)) {
                    etype = "Symbol";
                }
                else if (rb_special_const_p(x)) {
                    etype = RSTRING(rb_obj_as_string(x))->ptr;
                }
                else {
                    etype = rb_obj_classname(x);
                }
                rb_raise(rb_eTypeError, "wrong argument type %s (expected %s)",
                         etype, type->name);
            }
            type++;
        }
        rb_bug("unknown type 0x%x", t);
    }
}

/* exception classes */
#include <errno.h>

VALUE rb_eException;
VALUE rb_eSystemExit;
VALUE rb_eInterrupt;
VALUE rb_eSignal;
VALUE rb_eFatal;
VALUE rb_eStandardError;
VALUE rb_eRuntimeError;
VALUE rb_eTypeError;
VALUE rb_eArgError;
VALUE rb_eIndexError;
VALUE rb_eRangeError;
VALUE rb_eNameError;
VALUE rb_eNoMethodError;
VALUE rb_eSecurityError;
VALUE rb_eNotImpError;
VALUE rb_eNoMemError;
static VALUE rb_cNameErrorMesg;

VALUE rb_eScriptError;
VALUE rb_eSyntaxError;
VALUE rb_eLoadError;

VALUE rb_eSystemCallError;
VALUE rb_mErrno;

VALUE
rb_exc_new(etype, ptr, len)
    VALUE etype;
    const char *ptr;
    long len;
{
    return rb_funcall(etype, rb_intern("new"), 1, rb_str_new(ptr, len));
}

VALUE
rb_exc_new2(etype, s)
    VALUE etype;
    const char *s;
{
    return rb_exc_new(etype, s, strlen(s));
}

VALUE
rb_exc_new3(etype, str)
    VALUE etype, str;
{
    StringValue(str);
    return rb_exc_new(etype, RSTRING(str)->ptr, RSTRING(str)->len);
}

/*
 * call-seq:
 *    Exception.new(msg = nil)   =>  exception
 *
 *  Construct a new Exception object, optionally passing in 
 *  a message.
 */

static VALUE
exc_initialize(argc, argv, exc)
    int argc;
    VALUE *argv;
    VALUE exc;
{
    VALUE arg;

    rb_scan_args(argc, argv, "01", &arg);
    rb_iv_set(exc, "mesg", arg);
    rb_iv_set(exc, "bt", Qnil);

    return exc;
}

/*
 *  Document-method: exception
 *
 *  call-seq:
 *     exc.exception(string) -> an_exception or exc
 *  
 *  With no argument, or if the argument is the same as the receiver,
 *  return the receiver. Otherwise, create a new
 *  exception object of the same class as the receiver, but with a
 *  message equal to <code>string.to_str</code>.
 *     
 */

static VALUE
exc_exception(argc, argv, self)
    int argc;
    VALUE *argv;
    VALUE self;
{
    VALUE exc;

    if (argc == 0) return self;
    if (argc == 1 && self == argv[0]) return self;
    exc = rb_obj_clone(self);
    exc_initialize(argc, argv, exc);

    return exc;
}

/*
 * call-seq:
 *   exception.to_s   =>  string
 *
 * Returns exception's message (or the name of the exception if
 * no message is set).
 */

static VALUE
exc_to_s(exc)
    VALUE exc;
{
    VALUE mesg = rb_attr_get(exc, rb_intern("mesg"));

    if (NIL_P(mesg)) return rb_class_name(CLASS_OF(exc));
    if (OBJ_TAINTED(exc)) OBJ_TAINT(mesg);
    return mesg;
}

/*
 * call-seq:
 *   exception.message   =>  string
 *   exception.to_str    =>  string
 *
 * Returns the result of invoking <code>exception.to_s</code>.
 * Normally this returns the exception's message or name. By
 * supplying a to_str method, exceptions are agreeing to
 * be used where Strings are expected.
 */

static VALUE
exc_to_str(exc)
    VALUE exc;
{
    return rb_funcall(exc, rb_intern("to_s"), 0, 0);
}

/*
 * call-seq:
 *   exception.inspect   => string
 *
 * Return this exception's class name an message
 */

static VALUE
exc_inspect(exc)
    VALUE exc;
{
    VALUE str, klass;

    klass = CLASS_OF(exc);
    exc = rb_obj_as_string(exc);
    if (RSTRING(exc)->len == 0) {
        return rb_str_dup(rb_class_name(klass));
    }

    str = rb_str_buf_new2("#<");
    klass = rb_class_name(klass);
    rb_str_buf_append(str, klass);
    rb_str_buf_cat(str, ": ", 2);
    rb_str_buf_append(str, exc);
    rb_str_buf_cat(str, ">", 1);

    return str;
}

/*
 *  call-seq:
 *     exception.backtrace    => array
 *  
 *  Returns any backtrace associated with the exception. The backtrace
 *  is an array of strings, each containing either ``filename:lineNo: in
 *  `method''' or ``filename:lineNo.''
 *     
 *     def a
 *       raise "boom"
 *     end
 *     
 *     def b
 *       a()
 *     end
 *     
 *     begin
 *       b()
 *     rescue => detail
 *       print detail.backtrace.join("\n")
 *     end
 *     
 *  <em>produces:</em>
 *     
 *     prog.rb:2:in `a'
 *     prog.rb:6:in `b'
 *     prog.rb:10
*/

static VALUE
exc_backtrace(exc)
    VALUE exc;
{
    ID bt = rb_intern("bt");

    if (!rb_ivar_defined(exc, bt)) return Qnil;
    return rb_ivar_get(exc, bt);
}

static VALUE
check_backtrace(bt)
    VALUE bt;
{
    long i;
    static char *err = "backtrace must be Array of String";

    if (!NIL_P(bt)) {
        int t = TYPE(bt);

        if (t == T_STRING) return rb_ary_new3(1, bt);
        if (t != T_ARRAY) {
            rb_raise(rb_eTypeError, err);
        }
        for (i=0;i<RARRAY(bt)->len;i++) {
            if (TYPE(RARRAY(bt)->ptr[i]) != T_STRING) {
                rb_raise(rb_eTypeError, err);
            }
        }
    }
    return bt;
}

/*
 *  call-seq:
 *     exc.set_backtrace(array)   =>  array
 *  
 *  Sets the backtrace information associated with <i>exc</i>. The
 *  argument must be an array of <code>String</code> objects in the
 *  format described in <code>Exception#backtrace</code>.
 *     
 */

static VALUE
exc_set_backtrace(exc, bt)
    VALUE exc;
    VALUE bt;
{
    return rb_iv_set(exc, "bt", check_backtrace(bt));
}

/*
 * call-seq:
 *   SystemExit.new(status=0)   => system_exit
 *
 * Create a new +SystemExit+ exception with the given status.
 */

static VALUE
exit_initialize(argc, argv, exc)
    int argc;
    VALUE *argv;
    VALUE exc;
{
    VALUE status = INT2FIX(EXIT_SUCCESS);
    if (argc > 0 && FIXNUM_P(argv[0])) {
        status = *argv++;
        --argc;
    }
    rb_call_super(argc, argv);
    rb_iv_set(exc, "status", status);
    return exc;
}


/*
 * call-seq:
 *   system_exit.status   => fixnum
 *
 * Return the status value associated with this system exit.
 */

static VALUE
exit_status(exc)
    VALUE exc;
{
    return rb_attr_get(exc, rb_intern("status"));
}


/*
 * call-seq:
 *   system_exit.success?  => true or false
 *
 * Returns +true+ if exiting successful, +false+ if not.
 */

static VALUE
exit_success_p(exc)
    VALUE exc;
{
    VALUE status = rb_attr_get(exc, rb_intern("status"));
    if (NIL_P(status)) return Qtrue;
    if (status == INT2FIX(EXIT_SUCCESS)) return Qtrue;
    return Qfalse;
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_name_error(ID id, const char *fmt, ...)
#else
rb_name_error(id, fmt, va_alist)
    ID id;
    const char *fmt;
    va_dcl
#endif
{
    VALUE exc, argv[2];
    va_list args;
    char buf[BUFSIZ];

    va_init_list(args, fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    va_end(args);

    argv[0] = rb_str_new2(buf);
    argv[1] = ID2SYM(id);
    exc = rb_class_new_instance(2, argv, rb_eNameError);
    rb_exc_raise(exc);
}

/*
 * call-seq:
 *   NameError.new(msg [, name])  => name_error
 *
 * Construct a new NameError exception. If given the <i>name</i>
 * parameter may subsequently be examined using the <code>NameError.name</code>
 * method.
 */

static VALUE
name_err_initialize(argc, argv, self)
    int argc;
    VALUE *argv;
    VALUE self;
{
    VALUE name;

    name = (argc > 1) ? argv[--argc] : Qnil;
    rb_call_super(argc, argv);
    rb_iv_set(self, "name", name);
    return self;
}

/*
 *  call-seq:
 *    name_error.name    =>  string or nil
 *
 *  Return the name associated with this NameError exception.
 */

static VALUE
name_err_name(self)
    VALUE self;
{
    return rb_attr_get(self, rb_intern("name"));
}

/*
 * call-seq:
 *  name_error.to_s   => string
 *
 * Produce a nicely-formated string representing the +NameError+.
 */

static VALUE
name_err_to_s(exc)
    VALUE exc;
{
    VALUE mesg = rb_attr_get(exc, rb_intern("mesg")), str = mesg;

    if (NIL_P(mesg)) return rb_class_name(CLASS_OF(exc));
    StringValue(str);
    if (str != mesg) {
        rb_iv_set(exc, "mesg", mesg = str);
    }
    if (OBJ_TAINTED(exc)) OBJ_TAINT(mesg);
    return mesg;
}

/*
 * call-seq:
 *   NoMethodError.new(msg, name [, args])  => no_method_error
 *
 * Construct a NoMethodError exception for a method of the given name
 * called with the given arguments. The name may be accessed using
 * the <code>#name</code> method on the resulting object, and the
 * arguments using the <code>#args</code> method.
 */

static VALUE
nometh_err_initialize(argc, argv, self)
    int argc;
    VALUE *argv;
    VALUE self;
{
    VALUE args = (argc > 2) ? argv[--argc] : Qnil;
    name_err_initialize(argc, argv, self);
    rb_iv_set(self, "args", args);
    return self;
}

/* :nodoc: */
static void
name_err_mesg_mark(ptr)
    VALUE *ptr;
{
    rb_gc_mark_locations(ptr, ptr+3);
}

/* :nodoc: */
static VALUE
name_err_mesg_new(obj, mesg, recv, method)
    VALUE obj, mesg, recv, method;
{
    VALUE *ptr = ALLOC_N(VALUE, 3);

    ptr[0] = mesg;
    ptr[1] = recv;
    ptr[2] = method;
    return Data_Wrap_Struct(rb_cNameErrorMesg, name_err_mesg_mark, -1, ptr);
}

/* :nodoc: */
static VALUE
name_err_mesg_to_str(obj)
    VALUE obj;
{
    VALUE *ptr, mesg;
    Data_Get_Struct(obj, VALUE, ptr);

    mesg = ptr[0];
    if (NIL_P(mesg)) return Qnil;
    else {
        char *desc = 0;
        VALUE d = 0, args[3];

        obj = ptr[1];
        switch (TYPE(obj)) {
          case T_NIL:
            desc = "nil";
            break;
          case T_TRUE:
            desc = "true";
            break;
          case T_FALSE:
            desc = "false";
            break;
          default:
            d = rb_protect(rb_inspect, obj, 0);
            if (NIL_P(d) || RSTRING(d)->len > 65) {
                d = rb_any_to_s(obj);
            }
            desc = RSTRING(d)->ptr;
            break;
        }
        if (desc && desc[0] != '#') {
            d = rb_str_new2(desc);
            rb_str_cat2(d, ":");
            rb_str_cat2(d, rb_obj_classname(obj));
        }
        args[0] = mesg;
        args[1] = ptr[2];
        args[2] = d;
        mesg = rb_f_sprintf(3, args);
    }
    if (OBJ_TAINTED(obj)) OBJ_TAINT(mesg);
    return mesg;
}

/* :nodoc: */
static VALUE
name_err_mesg_load(klass, str)
    VALUE klass, str;
{
    return str;
}

/*
 * call-seq:
 *   no_method_error.args  => obj
 *
 * Return the arguments passed in as the third parameter to
 * the constructor.
 */

static VALUE
nometh_err_args(self)
    VALUE self;
{
    return rb_attr_get(self, rb_intern("args"));
}

void
rb_invalid_str(str, type)
    const char *str, *type;
{
    VALUE s = rb_str_inspect(rb_str_new2(str));

    rb_raise(rb_eArgError, "invalid value for %s: %s", type, RSTRING(s)->ptr);
}

/* 
 *  Document-module: Errno
 *
 *  Ruby exception objects are subclasses of <code>Exception</code>.
 *  However, operating systems typically report errors using plain
 *  integers. Module <code>Errno</code> is created dynamically to map
 *  these operating system errors to Ruby classes, with each error
 *  number generating its own subclass of <code>SystemCallError</code>.
 *  As the subclass is created in module <code>Errno</code>, its name
 *  will start <code>Errno::</code>.
 *     
 *  The names of the <code>Errno::</code> classes depend on
 *  the environment in which Ruby runs. On a typical Unix or Windows
 *  platform, there are <code>Errno</code> classes such as
 *  <code>Errno::EACCES</code>, <code>Errno::EAGAIN</code>,
 *  <code>Errno::EINTR</code>, and so on.
 *     
 *  The integer operating system error number corresponding to a
 *  particular error is available as the class constant
 *  <code>Errno::</code><em>error</em><code>::Errno</code>.
 *     
 *     Errno::EACCES::Errno   #=> 13
 *     Errno::EAGAIN::Errno   #=> 11
 *     Errno::EINTR::Errno    #=> 4
 *     
 *  The full list of operating system errors on your particular platform
 *  are available as the constants of <code>Errno</code>.
 *
 *     Errno.constants   #=> E2BIG, EACCES, EADDRINUSE, EADDRNOTAVAIL, ...
 */

static st_table *syserr_tbl;

static VALUE
set_syserr(n, name)
    int n;
    const char *name;
{
    VALUE error;

    if (!st_lookup(syserr_tbl, n, &error)) {
        error = rb_define_class_under(rb_mErrno, name, rb_eSystemCallError);
        rb_define_const(error, "Errno", INT2NUM(n));
        st_add_direct(syserr_tbl, n, error);
    }
    else {
        rb_define_const(rb_mErrno, name, error);
    }
    return error;
}

static VALUE
get_syserr(n)
    int n;
{
    VALUE error;

    if (!st_lookup(syserr_tbl, n, &error)) {
        char name[8];   /* some Windows' errno have 5 digits. */

        snprintf(name, sizeof(name), "E%03d", n);
        error = set_syserr(n, name);
    }
    return error;
}

/*
 * call-seq:
 *   SystemCallError.new(msg, errno)  => system_call_error_subclass
 *
 * If _errno_ corresponds to a known system error code, constructs
 * the appropriate <code>Errno</code> class for that error, otherwise
 * constructs a generic <code>SystemCallError</code> object. The
 * error number is subsequently available via the <code>errno</code>
 * method.
 */

static VALUE
syserr_initialize(argc, argv, self)
    int argc;
    VALUE *argv;
    VALUE self;
{
#if !defined(_WIN32) && !defined(__VMS)
    char *strerror();
#endif
    char *err;
    VALUE mesg, error;
    VALUE klass = rb_obj_class(self);

    if (klass == rb_eSystemCallError) {
        rb_scan_args(argc, argv, "11", &mesg, &error);
        if (argc == 1 && FIXNUM_P(mesg)) {
            error = mesg; mesg = Qnil;
        }
        if (!NIL_P(error) && st_lookup(syserr_tbl, NUM2LONG(error), &klass)) {
            /* change class */
            if (TYPE(self) != T_OBJECT) { /* insurance to avoid type crash */
                rb_raise(rb_eTypeError, "invalid instance type");
            }
            RBASIC(self)->klass = klass;
        }
    }
    else {
        rb_scan_args(argc, argv, "01", &mesg);
        error = rb_const_get(klass, rb_intern("Errno"));
    }
    if (!NIL_P(error)) err = strerror(NUM2LONG(error));
    else err = "unknown error";
    if (!NIL_P(mesg)) {
        VALUE str = mesg;
        size_t len;

        StringValue(str);
        len = strlen(err)+RSTRING(str)->len+3;
        mesg = rb_str_new(0, len);
        snprintf(RSTRING(mesg)->ptr, len+1, "%s - %.*s", err,
                (int)RSTRING(str)->len, RSTRING(str)->ptr);
        rb_str_resize(mesg, strlen(RSTRING(mesg)->ptr));
    }
    else {
        mesg = rb_str_new2(err);
    }
    rb_call_super(1, &mesg);
    rb_iv_set(self, "errno", error);
    return self;
}

/*
 * call-seq:
 *   system_call_error.errno   => fixnum
 *
 * Return this SystemCallError's error number.
 */

static VALUE
syserr_errno(self)
    VALUE self;
{
    return rb_attr_get(self, rb_intern("errno"));
}

/*
 * call-seq:
 *   system_call_error === other  => true or false
 *
 * Return +true+ if the receiver is a generic +SystemCallError+, or
 * if the error numbers _self_ and _other_ are the same.
 */


static VALUE
syserr_eqq(self, exc)
    VALUE self, exc;
{
    VALUE num, e;

    if (!rb_obj_is_kind_of(exc, rb_eSystemCallError)) return Qfalse;
    if (self == rb_eSystemCallError) return Qtrue;

    num = rb_attr_get(exc, rb_intern("errno"));
    if (NIL_P(num)) {
        VALUE klass = CLASS_OF(exc);

        while (TYPE(klass) == T_ICLASS || FL_TEST(klass, FL_SINGLETON)) {
            klass = (VALUE)RCLASS(klass)->super;
        }
        num = rb_const_get(klass, rb_intern("Errno"));
    }
    e = rb_const_get(self, rb_intern("Errno"));
    if (FIXNUM_P(num) ? num == e : rb_equal(num, e))
        return Qtrue;
    return Qfalse;
}

/*
 *  Descendents of class <code>Exception</code> are used to communicate
 *  between <code>raise</code> methods and <code>rescue</code>
 *  statements in <code>begin/end</code> blocks. <code>Exception</code>
 *  objects carry information about the exception---its type (the
 *  exception's class name), an optional descriptive string, and
 *  optional traceback information. Programs may subclass 
 *  <code>Exception</code> to add additional information.
 */

void
Init_Exception()
{
    rb_eException   = rb_define_class("Exception", rb_cObject);
    rb_define_singleton_method(rb_eException, "exception", rb_class_new_instance, -1);
    rb_define_method(rb_eException, "exception", exc_exception, -1);
    rb_define_method(rb_eException, "initialize", exc_initialize, -1);
    rb_define_method(rb_eException, "to_s", exc_to_s, 0);
    rb_define_method(rb_eException, "to_str", exc_to_str, 0);
    rb_define_method(rb_eException, "message", exc_to_str, 0);
    rb_define_method(rb_eException, "inspect", exc_inspect, 0);
    rb_define_method(rb_eException, "backtrace", exc_backtrace, 0);
    rb_define_method(rb_eException, "set_backtrace", exc_set_backtrace, 1);

    rb_eSystemExit  = rb_define_class("SystemExit", rb_eException);
    rb_define_method(rb_eSystemExit, "initialize", exit_initialize, -1);
    rb_define_method(rb_eSystemExit, "status", exit_status, 0);
    rb_define_method(rb_eSystemExit, "success?", exit_success_p, 0);

    rb_eFatal       = rb_define_class("fatal", rb_eException);
    rb_eSignal      = rb_define_class("SignalException", rb_eException);
    rb_eInterrupt   = rb_define_class("Interrupt", rb_eSignal);

    rb_eStandardError = rb_define_class("StandardError", rb_eException);
    rb_eTypeError     = rb_define_class("TypeError", rb_eStandardError);
    rb_eArgError      = rb_define_class("ArgumentError", rb_eStandardError);
    rb_eIndexError    = rb_define_class("IndexError", rb_eStandardError);
    rb_eRangeError    = rb_define_class("RangeError", rb_eStandardError);
    rb_eNameError     = rb_define_class("NameError", rb_eStandardError);
    rb_define_method(rb_eNameError, "initialize", name_err_initialize, -1);
    rb_define_method(rb_eNameError, "name", name_err_name, 0);
    rb_define_method(rb_eNameError, "to_s", name_err_to_s, 0);
    rb_cNameErrorMesg = rb_define_class_under(rb_eNameError, "message", rb_cData);
    rb_define_singleton_method(rb_cNameErrorMesg, "!", name_err_mesg_new, 3);
    rb_define_method(rb_cNameErrorMesg, "to_str", name_err_mesg_to_str, 0);
    rb_define_method(rb_cNameErrorMesg, "_dump", name_err_mesg_to_str, 1);
    rb_define_singleton_method(rb_cNameErrorMesg, "_load", name_err_mesg_load, 1);
    rb_eNoMethodError = rb_define_class("NoMethodError", rb_eNameError);
    rb_define_method(rb_eNoMethodError, "initialize", nometh_err_initialize, -1);
    rb_define_method(rb_eNoMethodError, "args", nometh_err_args, 0);

    rb_eScriptError = rb_define_class("ScriptError", rb_eException);
    rb_eSyntaxError = rb_define_class("SyntaxError", rb_eScriptError);
    rb_eLoadError   = rb_define_class("LoadError", rb_eScriptError);
    rb_eNotImpError = rb_define_class("NotImplementedError", rb_eScriptError);

    rb_eRuntimeError = rb_define_class("RuntimeError", rb_eStandardError);
    rb_eSecurityError = rb_define_class("SecurityError", rb_eStandardError);
    rb_eNoMemError = rb_define_class("NoMemoryError", rb_eException);

    syserr_tbl = st_init_numtable();
    rb_eSystemCallError = rb_define_class("SystemCallError", rb_eStandardError);
    rb_define_method(rb_eSystemCallError, "initialize", syserr_initialize, -1);
    rb_define_method(rb_eSystemCallError, "errno", syserr_errno, 0);
    rb_define_singleton_method(rb_eSystemCallError, "===", syserr_eqq, 1);

    rb_mErrno = rb_define_module("Errno");

    rb_define_global_function("warn", rb_warn_m, 1);
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_raise(VALUE exc, const char *fmt, ...)
#else
rb_raise(exc, fmt, va_alist)
    VALUE exc;
    const char *fmt;
    va_dcl
#endif
{
    va_list args;
    char buf[BUFSIZ];

    va_init_list(args,fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    va_end(args);
    rb_exc_raise(rb_exc_new2(exc, buf));
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_loaderror(const char *fmt, ...)
#else
rb_loaderror(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    va_list args;
    char buf[BUFSIZ];

    va_init_list(args, fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    va_end(args);
    rb_exc_raise(rb_exc_new2(rb_eLoadError, buf));
}

void
rb_notimplement()
{
    rb_raise(rb_eNotImpError,
             "the %s() function is unimplemented on this machine",
             rb_id2name(ruby_frame->last_func));
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_fatal(const char *fmt, ...)
#else
rb_fatal(fmt, va_alist)
    const char *fmt;
    va_dcl
#endif
{
    va_list args;
    char buf[BUFSIZ];

    va_init_list(args, fmt);
    vsnprintf(buf, BUFSIZ, fmt, args);
    va_end(args);

    ruby_in_eval = 0;
    rb_exc_fatal(rb_exc_new2(rb_eFatal, buf));
}

void
rb_sys_fail(mesg)
    const char *mesg;
{
    int n = errno;
    VALUE arg;

    errno = 0;
    if (n == 0) {
        rb_bug("rb_sys_fail(%s) - errno == 0", mesg ? mesg : "");
    }

    arg = mesg ? rb_str_new2(mesg) : Qnil;
    rb_exc_raise(rb_class_new_instance(1, &arg, get_syserr(n)));
}

void
#ifdef HAVE_STDARG_PROTOTYPES
rb_sys_warning(const char *fmt, ...)
#else
rb_sys_warning(fmt, va_alist)
     const char *fmt;
     va_dcl
#endif
{
     char buf[BUFSIZ];
     va_list args;
     int errno_save;
     
     errno_save = errno;

     if (!RTEST(ruby_verbose)) return;

     snprintf(buf, BUFSIZ, "warning: %s", fmt);
     snprintf(buf+strlen(buf), BUFSIZ-strlen(buf), ": %s", strerror(errno_save));
     
     va_init_list(args, fmt);
     warn_print(buf, args);
     va_end(args);
     errno = errno_save;
}

void
rb_load_fail(path)
    const char *path;
{
    rb_loaderror("%s -- %s", strerror(errno), path);
}

void
rb_error_frozen(what)
    const char *what;
{
    rb_raise(rb_eTypeError, "can't modify frozen %s", what);
}

void
rb_check_frozen(obj)
    VALUE obj;
{
    if (OBJ_FROZEN(obj)) rb_error_frozen(rb_obj_classname(obj));
}

void
Init_syserr()
{
#ifdef EPERM
    set_syserr(EPERM, "EPERM");
#endif
#ifdef ENOENT
    set_syserr(ENOENT, "ENOENT");
#endif
#ifdef ESRCH
    set_syserr(ESRCH, "ESRCH");
#endif
#ifdef EINTR
    set_syserr(EINTR, "EINTR");
#endif
#ifdef EIO
    set_syserr(EIO, "EIO");
#endif
#ifdef ENXIO
    set_syserr(ENXIO, "ENXIO");
#endif
#ifdef E2BIG
    set_syserr(E2BIG, "E2BIG");
#endif
#ifdef ENOEXEC
    set_syserr(ENOEXEC, "ENOEXEC");
#endif
#ifdef EBADF
    set_syserr(EBADF, "EBADF");
#endif
#ifdef ECHILD
    set_syserr(ECHILD, "ECHILD");
#endif
#ifdef EAGAIN
    set_syserr(EAGAIN, "EAGAIN");
#endif
#ifdef ENOMEM
    set_syserr(ENOMEM, "ENOMEM");
#endif
#ifdef EACCES
    set_syserr(EACCES, "EACCES");
#endif
#ifdef EFAULT
    set_syserr(EFAULT, "EFAULT");
#endif
#ifdef ENOTBLK
    set_syserr(ENOTBLK, "ENOTBLK");
#endif
#ifdef EBUSY
    set_syserr(EBUSY, "EBUSY");
#endif
#ifdef EEXIST
    set_syserr(EEXIST, "EEXIST");
#endif
#ifdef EXDEV
    set_syserr(EXDEV, "EXDEV");
#endif
#ifdef ENODEV
    set_syserr(ENODEV, "ENODEV");
#endif
#ifdef ENOTDIR
    set_syserr(ENOTDIR, "ENOTDIR");
#endif
#ifdef EISDIR
    set_syserr(EISDIR, "EISDIR");
#endif
#ifdef EINVAL
    set_syserr(EINVAL, "EINVAL");
#endif
#ifdef ENFILE
    set_syserr(ENFILE, "ENFILE");
#endif
#ifdef EMFILE
    set_syserr(EMFILE, "EMFILE");
#endif
#ifdef ENOTTY
    set_syserr(ENOTTY, "ENOTTY");
#endif
#ifdef ETXTBSY
    set_syserr(ETXTBSY, "ETXTBSY");
#endif
#ifdef EFBIG
    set_syserr(EFBIG, "EFBIG");
#endif
#ifdef ENOSPC
    set_syserr(ENOSPC, "ENOSPC");
#endif
#ifdef ESPIPE
    set_syserr(ESPIPE, "ESPIPE");
#endif
#ifdef EROFS
    set_syserr(EROFS, "EROFS");
#endif
#ifdef EMLINK
    set_syserr(EMLINK, "EMLINK");
#endif
#ifdef EPIPE
    set_syserr(EPIPE, "EPIPE");
#endif
#ifdef EDOM
    set_syserr(EDOM, "EDOM");
#endif
#ifdef ERANGE
    set_syserr(ERANGE, "ERANGE");
#endif
#ifdef EDEADLK
    set_syserr(EDEADLK, "EDEADLK");
#endif
#ifdef ENAMETOOLONG
    set_syserr(ENAMETOOLONG, "ENAMETOOLONG");
#endif
#ifdef ENOLCK
    set_syserr(ENOLCK, "ENOLCK");
#endif
#ifdef ENOSYS
    set_syserr(ENOSYS, "ENOSYS");
#endif
#ifdef ENOTEMPTY
    set_syserr(ENOTEMPTY, "ENOTEMPTY");
#endif
#ifdef ELOOP
    set_syserr(ELOOP, "ELOOP");
#endif
#ifdef EWOULDBLOCK
    set_syserr(EWOULDBLOCK, "EWOULDBLOCK");
#endif
#ifdef ENOMSG
    set_syserr(ENOMSG, "ENOMSG");
#endif
#ifdef EIDRM
    set_syserr(EIDRM, "EIDRM");
#endif
#ifdef ECHRNG
    set_syserr(ECHRNG, "ECHRNG");
#endif
#ifdef EL2NSYNC
    set_syserr(EL2NSYNC, "EL2NSYNC");
#endif
#ifdef EL3HLT
    set_syserr(EL3HLT, "EL3HLT");
#endif
#ifdef EL3RST
    set_syserr(EL3RST, "EL3RST");
#endif
#ifdef ELNRNG
    set_syserr(ELNRNG, "ELNRNG");
#endif
#ifdef EUNATCH
    set_syserr(EUNATCH, "EUNATCH");
#endif
#ifdef ENOCSI
    set_syserr(ENOCSI, "ENOCSI");
#endif
#ifdef EL2HLT
    set_syserr(EL2HLT, "EL2HLT");
#endif
#ifdef EBADE
    set_syserr(EBADE, "EBADE");
#endif
#ifdef EBADR
    set_syserr(EBADR, "EBADR");
#endif
#ifdef EXFULL
    set_syserr(EXFULL, "EXFULL");
#endif
#ifdef ENOANO
    set_syserr(ENOANO, "ENOANO");
#endif
#ifdef EBADRQC
    set_syserr(EBADRQC, "EBADRQC");
#endif
#ifdef EBADSLT
    set_syserr(EBADSLT, "EBADSLT");
#endif
#ifdef EDEADLOCK
    set_syserr(EDEADLOCK, "EDEADLOCK");
#endif
#ifdef EBFONT
    set_syserr(EBFONT, "EBFONT");
#endif
#ifdef ENOSTR
    set_syserr(ENOSTR, "ENOSTR");
#endif
#ifdef ENODATA
    set_syserr(ENODATA, "ENODATA");
#endif
#ifdef ETIME
    set_syserr(ETIME, "ETIME");
#endif
#ifdef ENOSR
    set_syserr(ENOSR, "ENOSR");
#endif
#ifdef ENONET
    set_syserr(ENONET, "ENONET");
#endif
#ifdef ENOPKG
    set_syserr(ENOPKG, "ENOPKG");
#endif
#ifdef EREMOTE
    set_syserr(EREMOTE, "EREMOTE");
#endif
#ifdef ENOLINK
    set_syserr(ENOLINK, "ENOLINK");
#endif
#ifdef EADV
    set_syserr(EADV, "EADV");
#endif
#ifdef ESRMNT
    set_syserr(ESRMNT, "ESRMNT");
#endif
#ifdef ECOMM
    set_syserr(ECOMM, "ECOMM");
#endif
#ifdef EPROTO
    set_syserr(EPROTO, "EPROTO");
#endif
#ifdef EMULTIHOP
    set_syserr(EMULTIHOP, "EMULTIHOP");
#endif
#ifdef EDOTDOT
    set_syserr(EDOTDOT, "EDOTDOT");
#endif
#ifdef EBADMSG
    set_syserr(EBADMSG, "EBADMSG");
#endif
#ifdef EOVERFLOW
    set_syserr(EOVERFLOW, "EOVERFLOW");
#endif
#ifdef ENOTUNIQ
    set_syserr(ENOTUNIQ, "ENOTUNIQ");
#endif
#ifdef EBADFD
    set_syserr(EBADFD, "EBADFD");
#endif
#ifdef EREMCHG
    set_syserr(EREMCHG, "EREMCHG");
#endif
#ifdef ELIBACC
    set_syserr(ELIBACC, "ELIBACC");
#endif
#ifdef ELIBBAD
    set_syserr(ELIBBAD, "ELIBBAD");
#endif
#ifdef ELIBSCN
    set_syserr(ELIBSCN, "ELIBSCN");
#endif
#ifdef ELIBMAX
    set_syserr(ELIBMAX, "ELIBMAX");
#endif
#ifdef ELIBEXEC
    set_syserr(ELIBEXEC, "ELIBEXEC");
#endif
#ifdef EILSEQ
    set_syserr(EILSEQ, "EILSEQ");
#endif
#ifdef ERESTART
    set_syserr(ERESTART, "ERESTART");
#endif
#ifdef ESTRPIPE
    set_syserr(ESTRPIPE, "ESTRPIPE");
#endif
#ifdef EUSERS
    set_syserr(EUSERS, "EUSERS");
#endif
#ifdef ENOTSOCK
    set_syserr(ENOTSOCK, "ENOTSOCK");
#endif
#ifdef EDESTADDRREQ
    set_syserr(EDESTADDRREQ, "EDESTADDRREQ");
#endif
#ifdef EMSGSIZE
    set_syserr(EMSGSIZE, "EMSGSIZE");
#endif
#ifdef EPROTOTYPE
    set_syserr(EPROTOTYPE, "EPROTOTYPE");
#endif
#ifdef ENOPROTOOPT
    set_syserr(ENOPROTOOPT, "ENOPROTOOPT");
#endif
#ifdef EPROTONOSUPPORT
    set_syserr(EPROTONOSUPPORT, "EPROTONOSUPPORT");
#endif
#ifdef ESOCKTNOSUPPORT
    set_syserr(ESOCKTNOSUPPORT, "ESOCKTNOSUPPORT");
#endif
#ifdef EOPNOTSUPP
    set_syserr(EOPNOTSUPP, "EOPNOTSUPP");
#endif
#ifdef EPFNOSUPPORT
    set_syserr(EPFNOSUPPORT, "EPFNOSUPPORT");
#endif
#ifdef EAFNOSUPPORT
    set_syserr(EAFNOSUPPORT, "EAFNOSUPPORT");
#endif
#ifdef EADDRINUSE
    set_syserr(EADDRINUSE, "EADDRINUSE");
#endif
#ifdef EADDRNOTAVAIL
    set_syserr(EADDRNOTAVAIL, "EADDRNOTAVAIL");
#endif
#ifdef ENETDOWN
    set_syserr(ENETDOWN, "ENETDOWN");
#endif
#ifdef ENETUNREACH
    set_syserr(ENETUNREACH, "ENETUNREACH");
#endif
#ifdef ENETRESET
    set_syserr(ENETRESET, "EN