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Member "pigz-2.8/try.c" (12 Apr 2021, 2616 Bytes) of package /linux/privat/pigz-2.8.tar.gz:

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    1 /* try.c -- try / catch / throw exception handling for C99
    2  * For copyright, version, and conditions of distribution and use, see try.h
    3  */
    4 
    5 /* See try.h for documentation.  This source file provides the global pointer
    6    and the functions needed by throw().  The pointer is thread-unique if
    7    pthread.h is included in try.h. */
    8 
    9 #include "try.h"
   10 #include <stdio.h>
   11 #include <string.h>
   12 #include <stdarg.h>
   13 
   14 /* Set up the try stack with a global pointer to the next try block.  The
   15    global is thread-unique if pthread.h is included in try.h. */
   16 #ifdef PTHREAD_ONCE_INIT
   17     pthread_key_t try_key_;
   18     static pthread_once_t try_once_ = PTHREAD_ONCE_INIT;
   19     static void try_create_(void)
   20     {
   21         int ret = pthread_key_create(&try_key_, NULL);
   22         assert(ret == 0 && "try: pthread_key_create() failed");
   23     }
   24     void try_setup_(void)
   25     {
   26         int ret = pthread_once(&try_once_, try_create_);
   27         assert(ret == 0 && "try: pthread_once() failed");
   28     }
   29 #else /* !PTHREAD_ONCE_INIT */
   30     try_t_ *try_stack_ = NULL;
   31 #endif /* PTHREAD_ONCE_INIT */
   32 
   33 /* Throw an exception.  This must always have at least two arguments, where the
   34    second argument can be a NULL.  The throw() macro is permitted to have one
   35    argument, since it appends a NULL argument in the call to this function. */
   36 void try_throw_(int code, char *fmt, ...)
   37 {
   38     /* save the thrown information in the try stack before jumping */
   39     try_setup_();
   40     assert(try_stack_ != NULL && "try: naked throw");
   41     try_stack_->ball.ret = 1;
   42     try_stack_->ball.code = code;
   43     try_stack_->ball.free = 0;
   44     try_stack_->ball.why = fmt;
   45 
   46     /* consider the second argument to be a string, and if it has formatting
   47        commands, process them with the subsequent arguments of throw, saving
   48        the result in allocated memory -- this if statement and clause must be
   49        updated for a different interpretation of the throw() arguments and
   50        different contents of the ball_t structure */
   51     if (fmt != NULL && strchr(fmt, '%') != NULL) {
   52         char *why, nul[1];
   53         size_t len;
   54         va_list ap1, ap2;
   55 
   56         va_start(ap1, fmt);
   57         va_copy(ap2, ap1);
   58         len = vsnprintf(nul, 1, fmt, ap1);
   59         va_end(ap1);
   60         why = malloc(len + 1);
   61         if (why == NULL)
   62             try_stack_->ball.why = "try: out of memory";
   63         else {
   64             vsnprintf(why, len + 1, fmt, ap2);
   65             va_end(ap2);
   66             try_stack_->ball.free = 1;
   67             try_stack_->ball.why = why;
   68         }
   69     }
   70 
   71     /* jump to the end of the nearest enclosing try block */
   72     longjmp(try_stack_->env, 1);
   73 }