X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=hs-boehmgc.git;a=blobdiff_plain;f=gc-7.2%2Fextra%2Fsetjmp_t.c;fp=gc-7.2%2Fextra%2Fsetjmp_t.c;h=374c50cc9912ea00ee8dc1dd2db598b828aab927;hp=0000000000000000000000000000000000000000;hb=324587ba93dc77f37406d41fd2a20d0e0d94fb1d;hpb=2a4ea609491b225a1ceb06da70396e93916f137a

diff --git a/gc-7.2/extra/setjmp_t.c b/gc-7.2/extra/setjmp_t.c
new file mode 100644
index 0000000..374c50c
--- /dev/null
+++ b/gc-7.2/extra/setjmp_t.c
@@ -0,0 +1,137 @@
+/*
+ * 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               */
+/* 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(void)
+{
+    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(void)
+{
+    volatile int sp;
+    sp = (int)&sp;
+    return (int *)sp;
+}
+
+int main(void)
+{
+    volatile word sp;
+    long ps = GETPAGESIZE();
+    jmp_buf b;
+    register int x = (int)strlen("a");  /* 1, slightly disguised */
+    static int y = 0;
+
+    sp = (word)(&sp);
+    printf("This appears to be a %s running %s\n", MACH_TYPE, OS_TYPE);
+    if (nested_sp() < (int *)sp) {
+      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)sp + 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)sp + 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");
+#   else
+      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(int x)
+{
+    return(x);
+}