git.distorted.org.uk Git - u/mdw/putty/blob - puttymem.h

   1 /*
   2  * PuTTY memory-handling header.
   3  */
   4
   5 #ifndef PUTTY_PUTTYMEM_H
   6 #define PUTTY_PUTTYMEM_H
   7
   8 #include <stddef.h>                    /* for size_t */
   9 #include <string.h>                    /* for memcpy() */
  10
  11
  12 /* #define MALLOC_LOG  do this if you suspect putty of leaking memory */
  13 #ifdef MALLOC_LOG
  14 #define smalloc(z) (mlog(__FILE__,__LINE__), safemalloc(z,1))
  15 #define snmalloc(z,s) (mlog(__FILE__,__LINE__), safemalloc(z,s))
  16 #define srealloc(y,z) (mlog(__FILE__,__LINE__), saferealloc(y,z,1))
  17 #define snrealloc(y,z,s) (mlog(__FILE__,__LINE__), saferealloc(y,z,s))
  18 #define sfree(z) (mlog(__FILE__,__LINE__), safefree(z))
  19 void mlog(char *, int);
  20 #else
  21 #define smalloc(z) safemalloc(z,1)
  22 #define snmalloc safemalloc
  23 #define srealloc(y,z) saferealloc(y,z,1)
  24 #define snrealloc saferealloc
  25 #define sfree safefree
  26 #endif
  27
  28 void *safemalloc(size_t, size_t);
  29 void *saferealloc(void *, size_t, size_t);
  30 void safefree(void *);
  31
  32 /*
  33  * Direct use of smalloc within the code should be avoided where
  34  * possible, in favour of these type-casting macros which ensure
  35  * you don't mistakenly allocate enough space for one sort of
  36  * structure and assign it to a different sort of pointer.
  37  *
  38  * The nasty trick in sresize with sizeof arranges for the compiler,
  39  * in passing, to type-check the expression ((type *)0 == (ptr)), i.e.
  40  * to type-check that the input pointer is a pointer to the correct
  41  * type. The construction sizeof(stuff) ? (b) : (b) looks like a
  42  * violation of the first principle of safe macros, but in fact it's
  43  * OK - although it _expands_ the macro parameter more than once, it
  44  * only _evaluates_ it once, so it's still side-effect safe.
  45  */
  46 #define snew(type) ((type *)snmalloc(1, sizeof(type)))
  47 #define snewn(n, type) ((type *)snmalloc((n), sizeof(type)))
  48 #define sresize(ptr, n, type)                                           \
  49     ((type *)snrealloc(sizeof((type *)0 == (ptr)) ? (ptr) : (ptr),      \
  50                        (n), sizeof(type)))
  51
  52 #endif