[Python-checkins] CVS: python/dist/src/Include pymem.h,2.4,2.4.16.1 pyport.h,2.40,2.40.8.1

2002年3月05日 06:24:47 -0800

Update of /cvsroot/python/python/dist/src/Include
In directory usw-pr-cvs1:/tmp/cvs-serv12181
Modified Files:
 Tag: release22-maint
	pymem.h pyport.h 
Log Message:
backport tim_one's checkin of
 revision 2.5 of pymem.h
 revision 2.44 of pyport.h
Whether platform malloc(0) returns NULL has nothing to do with whether
platform realloc(p, 0) returns NULL, so MALLOC_ZERO_RETURNS_NULL can
be correctly undefined yet realloc(p, 0) can return NULL anyway.
Prevent realloc(p, 0) doing free(p) and returning NULL via a different
hack. Would probably be better to get rid of MALLOC_ZERO_RETURNS_NULL
entirely.
Bugfix candidate.
Index: pymem.h
===================================================================
RCS file: /cvsroot/python/python/dist/src/Include/pymem.h,v
retrieving revision 2.4
retrieving revision 2.4.16.1
diff -C2 -d -r2.4 -r2.4.16.1
*** pymem.h	26 Jul 2001 21:34:59 -0000	2.4
--- pymem.h	5 Mar 2002 14:24:45 -0000	2.4.16.1
***************
*** 112,122 ****
 #define PyMem_NEW(type, n) \
 	( (type *) PyMem_MALLOC(_PyMem_EXTRA + (n) * sizeof(type)) )
! #define PyMem_RESIZE(p, type, n) \
! 	if ((p) == NULL) \
! 		(p) = (type *)(PyMem_MALLOC( \
! 				 _PyMem_EXTRA + (n) * sizeof(type))); \
! 	else \
! 		(p) = (type *)(PyMem_REALLOC((p), \
! 				 _PyMem_EXTRA + (n) * sizeof(type)))
 #define PyMem_DEL(p) PyMem_FREE(p)

--- 112,127 ----
 #define PyMem_NEW(type, n) \
 	( (type *) PyMem_MALLOC(_PyMem_EXTRA + (n) * sizeof(type)) )
! 
! /* See comment near MALLOC_ZERO_RETURNS_NULL in pyport.h. */
! #define PyMem_RESIZE(p, type, n)			\
! 	do {						\
! 		size_t _sum = (n) * sizeof(type);	\
! 		if (!_sum)				\
! 			_sum = 1;			\
! 		(p) = (type *)((p) ?			\
! 			 PyMem_REALLOC(p, _sum) :	\
! 			 PyMem_MALLOC(_sum));	\
! 	} while (0)
! 
 #define PyMem_DEL(p) PyMem_FREE(p)

Index: pyport.h
===================================================================
RCS file: /cvsroot/python/python/dist/src/Include/pyport.h,v
retrieving revision 2.40
retrieving revision 2.40.8.1
diff -C2 -d -r2.40 -r2.40.8.1
*** pyport.h	27 Oct 2001 21:16:16 -0000	2.40
--- pyport.h	5 Mar 2002 14:24:45 -0000	2.40.8.1
***************
*** 365,370 ****

 #ifdef MALLOC_ZERO_RETURNS_NULL
! /* XXX Always allocate one extra byte, since some malloc's return NULL
! XXX for malloc(0) or realloc(p, 0). */
 #define _PyMem_EXTRA 1
 #else
--- 365,378 ----

 #ifdef MALLOC_ZERO_RETURNS_NULL
! /* Allocate an extra byte if the platform malloc(0) returns NULL.
! Caution: this bears no relation to whether realloc(p, 0) returns NULL
! when p != NULL. Even on platforms where malloc(0) does not return NULL,
! realloc(p, 0) may act like free(p) and return NULL. Examples include
! Windows, and Python's own obmalloc.c (as of 2-Mar-2002). For whatever
! reason, our docs promise that PyMem_Realloc(p, 0) won't act like
! free(p) or return NULL, so realloc() calls may have to be hacked
! too, but MALLOC_ZERO_RETURNS_NULL's state is irrelevant to realloc (it
! needs a different hack).
! */
 #define _PyMem_EXTRA 1
 #else