* except.c (expand_throw): Add static attribute to match
[official-gcc.git] / boehm-gc / setjmp_t.c
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1 /*
2 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
4 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
5 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
7 * Permission is hereby granted to use or copy this program
8 * for any purpose, provided the above notices are retained on all copies.
9 * Permission to modify the code and to distribute modified code is granted,
10 * provided the above notices are retained, and a notice that the code was
11 * modified is included with the above copyright notice.
13 /* Boehm, September 21, 1995 5:39 pm PDT */
15 /* Check whether setjmp actually saves registers in jmp_buf. */
16 /* If it doesn't, the generic mark_regs code won't work. */
17 /* Compilers vary as to whether they will put x in a */
18 /* (callee-save) register without -O. The code is */
19 /* contrived such that any decent compiler should put x in */
20 /* a callee-save register with -O. Thus it is is */
21 /* recommended that this be run optimized. (If the machine */
22 /* has no callee-save registers, then the generic code is */
23 /* safe, but this will not be noticed by this piece of */
24 /* code.) */
25 #include <stdio.h>
26 #include <setjmp.h>
27 #include <string.h>
28 #include "gcconfig.h"
30 #ifdef OS2
31 /* GETPAGESIZE() is set to getpagesize() by default, but that */
32 /* doesn't really exist, and the collector doesn't need it. */
33 #define INCL_DOSFILEMGR
34 #define INCL_DOSMISC
35 #define INCL_DOSERRORS
36 #include <os2.h>
38 int
39 getpagesize()
41 ULONG result[1];
43 if (DosQuerySysInfo(QSV_PAGE_SIZE, QSV_PAGE_SIZE,
44 (void *)result, sizeof(ULONG)) != NO_ERROR) {
45 fprintf(stderr, "DosQuerySysInfo failed\n");
46 result[0] = 4096;
48 return((int)(result[0]));
50 #endif
52 struct {char a_a; char * a_b;} a;
54 int * nested_sp()
56 int dummy;
58 return(&dummy);
61 main()
63 int dummy;
64 long ps = GETPAGESIZE();
65 jmp_buf b;
66 register int x = (int)strlen("a"); /* 1, slightly disguised */
67 static int y = 0;
69 printf("This appears to be a %s running %s\n", MACH_TYPE, OS_TYPE);
70 if (nested_sp() < &dummy) {
71 printf("Stack appears to grow down, which is the default.\n");
72 printf("A good guess for STACKBOTTOM on this machine is 0x%lx.\n",
73 ((unsigned long)(&dummy) + ps) & ~(ps-1));
74 } else {
75 printf("Stack appears to grow up.\n");
76 printf("Define STACK_GROWS_UP in gc_private.h\n");
77 printf("A good guess for STACKBOTTOM on this machine is 0x%lx.\n",
78 ((unsigned long)(&dummy) + ps) & ~(ps-1));
80 printf("Note that this may vary between machines of ostensibly\n");
81 printf("the same architecture (e.g. Sun 3/50s and 3/80s).\n");
82 printf("On many machines the value is not fixed.\n");
83 printf("A good guess for ALIGNMENT on this machine is %ld.\n",
84 (unsigned long)(&(a.a_b))-(unsigned long)(&a));
86 /* Encourage the compiler to keep x in a callee-save register */
87 x = 2*x-1;
88 printf("");
89 x = 2*x-1;
90 setjmp(b);
91 if (y == 1) {
92 if (x == 2) {
93 printf("Generic mark_regs code probably wont work\n");
94 # if defined(SPARC) || defined(RS6000) || defined(VAX) || defined(MIPS) || defined(M68K) || defined(I386) || defined(NS32K) || defined(RT)
95 printf("Assembly code supplied\n");
96 # else
97 printf("Need assembly code\n");
98 # endif
99 } else if (x == 1) {
100 printf("Generic mark_regs code may work\n");
101 } else {
102 printf("Very strange setjmp implementation\n");
105 y++;
106 x = 2;
107 if (y == 1) longjmp(b,1);
108 return(0);
111 int g(x)
112 int x;
114 return(x);