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/*
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
/* Check whether setjmp actually saves registers in jmp_buf. */
/* If it doesn't, the generic mark_regs code won't work. */
/* Compilers vary as to whether they will put x in a */
/* (callee-save) register without -O. The code is */
/* contrived such that any decent compiler should put x in */
/* a callee-save register with -O. Thus it is is */
/* recommended that this be run optimized. (If the machine */
/* has no callee-save registers, then the generic code is */
/* safe, but this will not be noticed by this piece of */
/* code.) This test appears to be far from perfect. */
#include <stdio.h>
#include <setjmp.h>
#include <string.h>
#include "private/gcconfig.h"
#ifdef OS2
/* GETPAGESIZE() is set to getpagesize() by default, but that */
/* doesn't really exist, and the collector doesn't need it. */
#define INCL_DOSFILEMGR
#define INCL_DOSMISC
#define INCL_DOSERRORS
#include <os2.h>
int
getpagesize()
{
ULONG result[1];
if (DosQuerySysInfo(QSV_PAGE_SIZE, QSV_PAGE_SIZE,
(void *)result, sizeof(ULONG)) != NO_ERROR) {
fprintf(stderr, "DosQuerySysInfo failed\n");
result[0] = 4096;
}
return((int)(result[0]));
}
#endif
struct {char a_a; char * a_b;} a;
int * nested_sp()
{
int dummy;
return(&dummy);
}
main()
{
int dummy;
long ps = GETPAGESIZE();
jmp_buf b;
register int x = (int)strlen("a"); /* 1, slightly disguised */
static int y = 0;
printf("This appears to be a %s running %s\n", MACH_TYPE, OS_TYPE);
if (nested_sp() < &dummy) {
printf("Stack appears to grow down, which is the default.\n");
printf("A good guess for STACKBOTTOM on this machine is 0x%lx.\n",
((unsigned long)(&dummy) + ps) & ~(ps-1));
} else {
printf("Stack appears to grow up.\n");
printf("Define STACK_GROWS_UP in gc_private.h\n");
printf("A good guess for STACKBOTTOM on this machine is 0x%lx.\n",
((unsigned long)(&dummy) + ps) & ~(ps-1));
}
printf("Note that this may vary between machines of ostensibly\n");
printf("the same architecture (e.g. Sun 3/50s and 3/80s).\n");
printf("On many machines the value is not fixed.\n");
printf("A good guess for ALIGNMENT on this machine is %ld.\n",
(unsigned long)(&(a.a_b))-(unsigned long)(&a));
/* Encourage the compiler to keep x in a callee-save register */
x = 2*x-1;
printf("");
x = 2*x-1;
setjmp(b);
if (y == 1) {
if (x == 2) {
printf("Generic mark_regs code probably wont work\n");
# if defined(SPARC) || defined(RS6000) || defined(VAX) || defined(MIPS) || defined(M68K) || defined(I386) || defined(NS32K) || defined(RT)
printf("Assembly code supplied\n");
# else
printf("Need assembly code\n");
# endif
} else if (x == 1) {
printf("Generic mark_regs code may work\n");
} else {
printf("Very strange setjmp implementation\n");
}
}
y++;
x = 2;
if (y == 1) longjmp(b,1);
return(0);
}
int g(x)
int x;
{
return(x);
}
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