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/*
* PuTTY memory-handling header.
*/
#ifndef PUTTY_PUTTYMEM_H
#define PUTTY_PUTTYMEM_H
#include <stddef.h> /* for size_t */
#include <string.h> /* for memcpy() */
#include "defs.h"
#define smalloc(z) safemalloc(z,1,0)
#define snmalloc safemalloc
#define srealloc(y,z) saferealloc(y,z,1)
#define snrealloc saferealloc
#define sfree safefree
void *safemalloc(size_t factor1, size_t factor2, size_t addend);
void *saferealloc(void *, size_t, size_t);
void safefree(void *);
/*
* Direct use of smalloc within the code should be avoided where
* possible, in favour of these type-casting macros which ensure you
* don't mistakenly allocate enough space for one sort of structure
* and assign it to a different sort of pointer. sresize also uses
* TYPECHECK to verify that the _input_ pointer is a pointer to the
* correct type.
*/
#define snew(type) ((type *)snmalloc(1, sizeof(type), 0))
#define snewn(n, type) ((type *)snmalloc((n), sizeof(type), 0))
#define sresize(ptr, n, type) TYPECHECK((type *)0 == (ptr), \
((type *)snrealloc((ptr), (n), sizeof(type))))
/*
* For cases where you want to allocate a struct plus a subsidiary
* data buffer in one step, this macro lets you add a constant to the
* amount malloced.
*
* Since the return value is already cast to the struct type, a
* pointer to that many bytes of extra data can be conveniently
* obtained by simply adding 1 to the returned pointer!
* snew_plus_get_aux is a handy macro that does that and casts the
* result to void *, so you can assign it straight to wherever you
* wanted it.
*/
#define snew_plus(type, extra) ((type *)snmalloc(1, sizeof(type), (extra)))
#define snew_plus_get_aux(ptr) ((void *)((ptr) + 1))
/*
* Helper macros to deal with the common use case of growing an array.
*
* The common setup is that 'array' is a pointer to the first element
* of a dynamic array of some type, and 'size' represents the current
* allocated size of that array (in elements). Both of those macro
* parameters are implicitly written back to.
*
* Then sgrowarray(array, size, n) means: make sure the nth element of
* the array exists (i.e. the size is at least n+1). You call that
* before writing to the nth element, if you're looping round
* appending to the array.
*
* If you need to grow the array by more than one element, you can
* instead call sgrowarrayn(array, size, n, m), which will ensure the
* size of the array is at least n+m. (So sgrowarray is just the
* special case of that in which m == 1.)
*
* It's common to call sgrowarrayn with one of n,m equal to the
* previous logical length of the array, and the other equal to the
* new number of logical entries you want to add, so that n <= size on
* entry. But that's not actually a mandatory precondition: the two
* length parameters are just arbitrary integers that get added
* together with an initial check for overflow, and the semantics are
* simply 'make sure the array is big enough to take their sum, no
* matter how big it was to start with'.)
*
* Another occasionally useful idiom is to call sgrowarray with n ==
* size, i.e. sgrowarray(array, size, size). That just means: make
* array bigger by _some_ amount, I don't particularly mind how much.
* You might use that style if you were repeatedly calling an API
* function outside your control, which would either fill your buffer
* and return success, or else return a 'too big' error without
* telling you how much bigger it needed to be.
*
* The _nm variants of the macro set the 'private' flag in the
* underlying function, which forces array resizes to be done by a
* manual allocate/copy/free instead of realloc, with careful clearing
* of the previous memory block before we free it. This costs
* performance, but if the block contains important secrets such as
* private keys or passwords, it avoids the risk that a realloc that
* moves the memory block might leave a copy of the data visible in
* the freed memory at the previous location.
*/
void *safegrowarray(void *array, size_t *size, size_t eltsize,
size_t oldlen, size_t extralen, bool private);
/* The master macro wrapper, of which all others are special cases */
#define sgrowarray_general(array, size, n, m, priv) \
((array) = safegrowarray(array, &(size), sizeof(*array), n, m, priv))
/* The special-case macros that are easier to use in most situations */
#define sgrowarrayn( a, s, n, m) sgrowarray_general(a, s, n, m, false)
#define sgrowarray( a, s, n ) sgrowarray_general(a, s, n, 1, false)
#define sgrowarrayn_nm(a, s, n, m) sgrowarray_general(a, s, n, m, true )
#define sgrowarray_nm( a, s, n ) sgrowarray_general(a, s, n, 1, true )
/*
* This function is called by the innermost safemalloc/saferealloc
* functions when allocation fails. Usually it's provided by an
* implementation in utils, which ties it into an application's
* existing modalfatalbox() system, but standalone test applications
* can reimplement it some other way if they prefer.
*/
NORETURN void out_of_memory(void);
#ifdef MINEFIELD
/*
* Definitions for Minefield, PuTTY's own Windows-specific malloc
* debugger in the style of Electric Fence. Implemented in
* windows/utils/minefield.c, and referred to by the main malloc
* wrappers in memory.c.
*/
void *minefield_c_malloc(size_t size);
void minefield_c_free(void *p);
void *minefield_c_realloc(void *p, size_t size);
#endif
#endif
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