mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-21 11:19:25 +08:00
90 lines
1.9 KiB
C
90 lines
1.9 KiB
C
/* Emulation of getpagesize() for systems that need it. */
|
|
|
|
/*
|
|
|
|
NAME
|
|
|
|
getpagesize -- return the number of bytes in page of memory
|
|
|
|
SYNOPSIS
|
|
|
|
int getpagesize (void)
|
|
|
|
DESCRIPTION
|
|
|
|
Returns the number of bytes in a page of memory. This is the
|
|
granularity of many of the system memory management routines.
|
|
No guarantee is made as to whether or not it is the same as the
|
|
basic memory management hardware page size.
|
|
|
|
BUGS
|
|
|
|
Is intended as a reasonable replacement for systems where this
|
|
is not provided as a system call. The value of 4096 may or may
|
|
not be correct for the systems where it is returned as the default
|
|
value.
|
|
|
|
*/
|
|
|
|
#ifndef VMS
|
|
|
|
#include <sys/types.h>
|
|
#ifndef NO_SYS_PARAM_H
|
|
#include <sys/param.h>
|
|
#endif
|
|
|
|
#ifdef HAVE_SYSCONF
|
|
#include <unistd.h>
|
|
#define GNU_OUR_PAGESIZE sysconf(_SC_PAGESIZE)
|
|
#else
|
|
#ifdef PAGESIZE
|
|
#define GNU_OUR_PAGESIZE PAGESIZE
|
|
#else /* no PAGESIZE */
|
|
#ifdef EXEC_PAGESIZE
|
|
#define GNU_OUR_PAGESIZE EXEC_PAGESIZE
|
|
#else /* no EXEC_PAGESIZE */
|
|
#ifdef NBPG
|
|
#define GNU_OUR_PAGESIZE (NBPG * CLSIZE)
|
|
#ifndef CLSIZE
|
|
#define CLSIZE 1
|
|
#endif /* CLSIZE */
|
|
#else /* no NBPG */
|
|
#ifdef NBPC
|
|
#define GNU_OUR_PAGESIZE NBPC
|
|
#else /* no NBPC */
|
|
#define GNU_OUR_PAGESIZE 4096 /* Just punt and use reasonable value */
|
|
#endif /* NBPC */
|
|
#endif /* NBPG */
|
|
#endif /* EXEC_PAGESIZE */
|
|
#endif /* PAGESIZE */
|
|
#endif /* HAVE_SYSCONF */
|
|
|
|
int
|
|
getpagesize ()
|
|
{
|
|
return (GNU_OUR_PAGESIZE);
|
|
}
|
|
|
|
#else /* VMS */
|
|
|
|
#if 0 /* older distributions of gcc-vms are missing <syidef.h> */
|
|
#include <syidef.h>
|
|
#endif
|
|
#ifndef SYI$_PAGE_SIZE /* VMS V5.4 and earlier didn't have this yet */
|
|
#define SYI$_PAGE_SIZE 4452
|
|
#endif
|
|
extern unsigned long lib$getsyi(const unsigned short *,...);
|
|
|
|
int getpagesize ()
|
|
{
|
|
long pagsiz = 0L;
|
|
unsigned short itmcod = SYI$_PAGE_SIZE;
|
|
|
|
(void) lib$getsyi (&itmcod, (void *) &pagsiz);
|
|
if (pagsiz == 0L)
|
|
pagsiz = 512L; /* VAX default */
|
|
return (int) pagsiz;
|
|
}
|
|
|
|
#endif /* VMS */
|