diff options
Diffstat (limited to 'tools/build/src/engine/boehm_gc/setjmp_t.c')
| -rw-r--r-- | tools/build/src/engine/boehm_gc/setjmp_t.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/tools/build/src/engine/boehm_gc/setjmp_t.c b/tools/build/src/engine/boehm_gc/setjmp_t.c new file mode 100644 index 000000000..5a171df0c --- /dev/null +++ b/tools/build/src/engine/boehm_gc/setjmp_t.c @@ -0,0 +1,135 @@ +/* + * 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/gc_priv.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); +} + +int 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)); + + printf("The following is a very dubious test of one root marking" + " strategy.\n"); + printf("Results may not be accurate/useful:\n"); + /* 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("Setjmp-based generic mark_regs code probably wont work.\n"); + printf("But we rarely try that anymore. If you have getcontect()\n"); + printf("this probably doesn't matter.\n"); + } else if (x == 1) { + printf("Setjmp-based register marking code may work.\n"); + } else { + printf("Very strange setjmp implementation.\n"); + } + } + y++; + x = 2; + if (y == 1) longjmp(b,1); + printf("Some GC internal configuration stuff: \n"); + printf("\tWORDSZ = %d, ALIGNMENT = %d, GC_GRANULE_BYTES = %d\n", + WORDSZ, ALIGNMENT, GC_GRANULE_BYTES); + printf("\tUsing one mark "); +# if defined(USE_MARK_BYTES) + printf("byte"); +# elif defined(USE_MARK_BITS) + printf("bit"); +# endif + printf(" per "); +# if defined(MARK_BIT_PER_OBJ) + printf("object.\n"); +# elif defined(MARK_BIT_PER_GRANULE) + printf("granule.\n"); +# endif +# ifdef THREAD_LOCAL_ALLOC + printf("Thread local allocation enabled.\n"); +# endif +# ifdef PARALLEL_MARK + printf("Parallel marking enabled.\n"); +# endif + return(0); +} + +int g(x) +int x; +{ + return(x); +} |