raisecond.c

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/* @(#)raisecond.c  1.22 09/07/10 Copyright 1985, 1989, 1995-2004 J. Schilling */
/*
 *  raise a condition (software signal)
 */
/*
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * See the file CDDL.Schily.txt in this distribution for details.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file CDDL.Schily.txt from this distribution.
 */
/*
 *  Check for installed condition handlers.
 *  If a handler is found, the function is called with the appropriate args.
 *  If no handler is found or no handler signals success,
 *  the program will be aborted.
 *
 *  Copyright (c) 1985, 1989, 1995-2004 J. Schilling
 */
#include <schily/mconfig.h>
#include <schily/stdio.h>
#include <schily/standard.h>
#include <schily/sigblk.h>
#include <schily/unistd.h>
#include <schily/stdlib.h>
#include <schily/string.h>
#include <schily/avoffset.h>
#include <schily/schily.h>

#if !defined(AV_OFFSET) || !defined(FP_INDIR)
#   ifdef   HAVE_SCANSTACK
#   undef   HAVE_SCANSTACK
#   endif
#endif

/*
 * Macros to print to stderr without stdio, to avoid screwing up.
 */
#ifndef STDERR_FILENO
#define STDERR_FILENO   2
#endif
#define eprints(a)  (void)write(STDERR_FILENO, (a), sizeof (a)-1)
#define eprintl(a)  (void)write(STDERR_FILENO, (a), strlen(a))

#define is_even(p)  ((((long)(p)) & 1) == 0)
#define even(p)     (((long)(p)) & ~1L)
#ifdef  __future__
#define even(p)     (((long)(p)) - 1) /* will this work with 64 bit ?? */
#endif


LOCAL   void raiseabort  __PR((const char *));

#ifdef  HAVE_SCANSTACK
#include <schily/stkframe.h>
#define next_frame(vp)  do {                            \
                if (((struct frame *)(vp))->fr_savfp == 0) { \
                    vp = (void *)0;             \
                    break;                  \
                }                       \
                if (((struct frame *)(vp))->fr_savpc == 0) { \
                    vp = (void *)0;             \
                    break;                  \
                }                       \
                vp =                        \
                    (void *)((struct frame *)(vp))->fr_savfp; \
            } while (vp != NULL && is_even(vp));            \
            vp = (struct frame *)even(vp);
#else
#if defined(IS_MACOS_X)
/*
 * The MAC OS X linker does not grok "common" varaibles.
 * Make __roothandle a "data" variable.
 */
EXPORT  SIGBLK  *__roothandle = 0;
#else
EXPORT  SIGBLK  *__roothandle;
#endif

#define next_frame(vp)  vp = (((SIGBLK *)(vp))->sb_savfp);
#endif

LOCAL   BOOL framehandle __PR((SIGBLK *, const char *, const char *, long));

/*
 *  Loop through the chain of procedure frames on the stack.
 *
 *  Frame pointers normally have even values.
 *  Frame pointers of procedures with an installed handler are marked odd.
 *  The even base value, in this case actually points to a SIGBLK which
 *  holds the saved "real" frame pointer.
 *  The SIGBLK mentioned above may me the start of a chain of SIGBLK's,
 *  containing different handlers.
 */
EXPORT void
raisecond(signame, arg2)
    const char  *signame;
    long        arg2;
{
    register void   *vp = NULL;

#ifdef  HAVE_SCANSTACK
    /*
     * As the SCO OpenServer C-Compiler has a bug that may cause
     * the first function call to getfp() been done before the
     * new stack frame is created, we call getfp() twice.
     */
    (void) getfp();
    vp = getfp();
    next_frame(vp);
#else
    vp = __roothandle;
#endif

    while (vp) {
        if (framehandle((SIGBLK *)vp, signame, signame, arg2))
            return;
        else if (framehandle((SIGBLK *)vp, "any_other", signame, arg2))
            return;
#ifdef  HAVE_SCANSTACK
        vp = (struct frame *)((SIGBLK *)vp)->sb_savfp;
#endif
        next_frame(vp);
    }
    /*
     * No matching handler that signals success found.
     * Print error message and abort.
     */
    raiseabort(signame);
    /* NOTREACHED */
}

/*
 *  Loop through the handler chain for a procedure frame.
 *
 *  If no handler with matching name is found, return FALSE,
 *  otherwise the first handler with matching name is called.
 *  The return value in the latter case depends on the called function.
 */
LOCAL BOOL
framehandle(sp, handlename, signame, arg2)
    register SIGBLK *sp;
    const char  *handlename;
    const char  *signame;
    long        arg2;
{
    for (; sp; sp = sp->sb_signext) {
        if (sp->sb_signame != NULL &&
            streql(sp->sb_signame, handlename)) {
            if (sp->sb_sigfun == NULL) {    /* deactivated */
                return (FALSE);
            } else {
                return (*sp->sb_sigfun)(signame,
                            sp->sb_sigarg, arg2);
            }
        }
    }
    return (FALSE);
}

LOCAL void
raiseabort(signame)
    const   char    *signame;
{
    eprints("Condition not caught: "); eprintl(signame); eprints(".\n");
    abort();
    /* NOTREACHED */
}