mdw@git.distorted.org.uk Git - sgt/agedu/blob - alloc.h

   1 /*
   2  * alloc.h: safe wrappers around malloc, realloc, free, strdup
   3  */
   4
   5 #ifndef AGEDU_ALLOC_H
   6 #define AGEDU_ALLOC_H
   7
   8 #include <stddef.h>
   9
  10 /*
  11  * smalloc should guarantee to return a useful pointer.
  12  */
  13 void *smalloc(size_t size);
  14
  15 /*
  16  * srealloc should guaranteeably be able to realloc NULL
  17  */
  18 void *srealloc(void *p, size_t size);
  19
  20 /*
  21  * sfree should guaranteeably deal gracefully with freeing NULL
  22  */
  23 void sfree(void *p);
  24
  25 /*
  26  * dupstr is like strdup, but with the never-return-NULL property
  27  * of smalloc (and also reliably defined in all environments :-)
  28  */
  29 char *dupstr(const char *s);
  30
  31 /*
  32  * dupfmt is a bit like printf, but does its own allocation and
  33  * returns a dynamic string. It also supports a different (and
  34  * much less featureful) set of format directives:
  35  *
  36  *  - %D takes no argument, and gives the current date and time in
  37  *    a format suitable for an HTTP Date header
  38  *  - %d takes an int argument and formats it like normal %d (but
  39  *    doesn't support any of the configurability of standard
  40  *    printf)
  41  *  - %s takes a const char * and formats it like normal %s
  42  *    (again, no fine-tuning available)
  43  *  - %h takes a const char * but escapes it so that it's safe for
  44  *    HTML
  45  *  - %S takes an int followed by a const char *. If the int is
  46  *    zero, it behaves just like %s. If the int is nonzero, it
  47  *    transforms the string by stuffing a \r before every \n.
  48  */
  49 char *dupfmt(const char *fmt, ...);
  50
  51 /*
  52  * snew allocates one instance of a given type, and casts the
  53  * result so as to type-check that you're assigning it to the
  54  * right kind of pointer. Protects against allocation bugs
  55  * involving allocating the wrong size of thing.
  56  */
  57 #define snew(type) \
  58     ( (type *) smalloc (sizeof (type)) )
  59
  60 /*
  61  * snewn allocates n instances of a given type, for arrays.
  62  */
  63 #define snewn(number, type) \
  64     ( (type *) smalloc ((number) * sizeof (type)) )
  65
  66 /*
  67  * sresize wraps realloc so that you specify the new number of
  68  * elements and the type of the element, with the same type-
  69  * checking advantages. Also type-checks the input pointer.
  70  */
  71 #define sresize(array, number, type) \
  72     ( (void)sizeof((array)-(type *)0), \
  73       (type *) srealloc ((array), (number) * sizeof (type)) )
  74
  75 #endif /* AGEDU_ALLOC_H */