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73ffefd0 TT |
1 | /* |
2 | * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved. | |
3 | * | |
4 | * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED | |
5 | * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. | |
6 | * | |
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. | |
12 | */ | |
13 | /* Boehm, September 21, 1995 5:39 pm PDT */ | |
14 | ||
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> | |
20bbd3cd | 28 | #include "gcconfig.h" |
73ffefd0 TT |
29 | |
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> | |
37 | ||
38 | int | |
39 | getpagesize() | |
40 | { | |
41 | ULONG result[1]; | |
42 | ||
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; | |
47 | } | |
48 | return((int)(result[0])); | |
49 | } | |
50 | #endif | |
51 | ||
52 | struct {char a_a; char * a_b;} a; | |
53 | ||
54 | int * nested_sp() | |
55 | { | |
56 | int dummy; | |
57 | ||
58 | return(&dummy); | |
59 | } | |
60 | ||
61 | main() | |
62 | { | |
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; | |
68 | ||
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)); | |
79 | } | |
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)); | |
85 | ||
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"); | |
103 | } | |
104 | } | |
105 | y++; | |
106 | x = 2; | |
107 | if (y == 1) longjmp(b,1); | |
108 | return(0); | |
109 | } | |
110 | ||
111 | int g(x) | |
112 | int x; | |
113 | { | |
114 | return(x); | |
115 | } |