* configure.in (rb_cv_stack_grow_dir): check stack growing direction.

* eval.c (rb_thread_restore_context): prior configuration macro.

* gc.c (ruby_stack_length): always return the address of lower edge.

* gc.c (rb_gc_mark_locations): remove margin.  [ruby-dev:20462]

* gc.c (rb_gc, Init_stack): prior configuration macro.

* gc.c (Init_stack): add safety margin.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4012 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 82 insertions, 26 deletions

diff --git a/ChangeLog b/ChangeLog
index b5479975ff..8636a10d7b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Sat Jun 28 12:28:54 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
+
+	* configure.in (rb_cv_stack_grow_dir): check stack growing direction.
+
+	* eval.c (rb_thread_restore_context): prior configuration macro.
+
+	* gc.c (ruby_stack_length): always return the address of lower edge.
+
+	* gc.c (rb_gc_mark_locations): remove margin.  [ruby-dev:20462]
+
+	* gc.c (rb_gc, Init_stack): prior configuration macro.
+
+	* gc.c (Init_stack): add safety margin.
+
 Fri Jun 27 14:41:22 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
 
 	* string.c (rb_str_split_m): remove white spaces on the head of
diff --git a/configure.in b/configure.in
index ec6abaef71..cebfc766b0 100644
--- a/configure.in
+++ b/configure.in
@@ -616,6 +616,30 @@ if test "$rb_cv_need_io_flush_before_seek" = yes; then
   AC_DEFINE(NEED_IO_FLUSH_BEFORE_SEEK, 1)
 fi
 
+case "$target_cpu" in
+m68*|i?86|sparc) rb_cv_stack_grow_dir=-1;;
+esac
+AC_CACHE_CHECK(stack growing direction, rb_cv_stack_grow_dir,
+  [AC_TRY_RUN([
+/* recurse to get rid of inlining */
+static int
+stack_growup_p(addr, n)
+    volatile int *addr, n;
+{
+    volatile int end;
+    if (n > 0)
+	return *addr = stack_growup_p(addr, n - 1);
+    else
+	return (&end > addr);
+}
+int main()
+{
+    int x;
+    return stack_growup_p(&x, 10);
+}
+], rb_cv_stack_grow_dir=-1, rb_cv_stack_grow_dir=+1, rb_cv_stack_grow_dir=0)])
+AC_DEFINE_UNQUOTED(STACK_GROW_DIRECTION, $rb_cv_stack_grow_dir)
+
 dnl default value for $KANJI
 DEFAULT_KCODE="KCODE_NONE"
 
diff --git a/eval.c b/eval.c
index 0468d37dc9..272d2f74f5 100644
--- a/eval.c
+++ b/eval.c
@@ -8112,8 +8112,7 @@ rb_thread_save_context(th)
 
     len = ruby_stack_length(&pos);
     th->stk_len = 0;
-    th->stk_pos = (rb_gc_stack_start<pos)?rb_gc_stack_start
-				         :rb_gc_stack_start - len;
+    th->stk_pos = pos;
     if (len > th->stk_max) {
 	REALLOC_N(th->stk_ptr, VALUE, len);
 	th->stk_max = len;
@@ -8211,6 +8210,11 @@ rb_thread_restore_context(th, exit)
 
     if (!th->stk_ptr) rb_bug("unsaved context");
 
+#if STACK_GROW_DIRECTION < 0
+    if (&v > th->stk_pos) stack_extend(th, exit);
+#elif STACK_GROW_DIRECTION > 0
+    if (&v < th->stk_pos + th->stk_len) stack_extend(th, exit);
+#else
     if (&v < rb_gc_stack_start) {
 	/* Stack grows downward */
 	if (&v > th->stk_pos) stack_extend(th, exit);
@@ -8219,6 +8223,7 @@ rb_thread_restore_context(th, exit)
 	/* Stack grows upward */
 	if (&v < th->stk_pos + th->stk_len) stack_extend(th, exit);
     }
+#endif
 
     rb_trap_immediate = 0;	/* inhibit interrupts from here */
     ruby_frame = th->frame;
diff --git a/gc.c b/gc.c
index 3c06bfc5da..9c8ac774f2 100644
--- a/gc.c
+++ b/gc.c
@@ -376,10 +376,30 @@ static unsigned int STACK_LEVEL_MAX = 655300;
 #endif
 #if defined(sparc) || defined(__sparc__)
 # define STACK_LENGTH  (rb_gc_stack_start - STACK_END + 0x80)
+#elif STACK_GROW_DIRECTION < 0
+# define STACK_LENGTH  (rb_gc_stack_start - STACK_END)
+#elif STACK_GROW_DIRECTION > 0
+# define STACK_LENGTH  (STACK_END - rb_gc_stack_start)
 #else
 # define STACK_LENGTH  ((STACK_END < rb_gc_stack_start) ? rb_gc_stack_start - STACK_END\
                                            : STACK_END - rb_gc_stack_start)
 #endif
+#if STACK_GROW_DIRECTION > 0
+# define STACK_UPPER(x, a, b) a
+#elif STACK_GROW_DIRECTION < 0
+# define STACK_UPPER(x, a, b) b
+#else
+static int
+stack_growup_p(addr)
+    VALUE *addr;
+{
+    SET_STACK_END;
+
+    if (STACK_END > addr) return Qtrue;
+    return Qfalse;
+}
+# define STACK_UPPER(x, a, b) (stack_growup_p(x) ? a : b)
+#endif
 
 #define GC_WARTER_MARK 512
 
@@ -393,7 +413,7 @@ ruby_stack_length(p)
     VALUE **p;
 {
     SET_STACK_END;
-    if (p) *p = STACK_END;
+    if (p) *p = STACK_UPPER(STACK_END, rb_gc_stack_start, STACK_END);
     return STACK_LENGTH;
 }
 
@@ -544,7 +564,7 @@ rb_gc_mark_locations(start, end)
 	start = end;
 	end = tmp;
     }
-    n = end - start + 1;
+    n = end - start;
     mark_locations_array(start,n);
 }
 
@@ -1227,10 +1247,19 @@ rb_gc()
     /* This assumes that all registers are saved into the jmp_buf */
     setjmp(save_regs_gc_mark);
     mark_locations_array((VALUE*)save_regs_gc_mark, sizeof(save_regs_gc_mark) / sizeof(VALUE *));
+#if STACK_GROW_DIRECTION < 0
+    rb_gc_mark_locations((VALUE*)STACK_END, rb_gc_stack_start);
+#elif STACK_GROW_DIRECTION > 0
     rb_gc_mark_locations(rb_gc_stack_start, (VALUE*)STACK_END);
+#else
+    if ((VALUE*)STACK_END < rb_gc_stack_start)
+	rb_gc_mark_locations((VALUE*)STACK_END, rb_gc_stack_start);
+    else
+	rb_gc_mark_locations(rb_gc_stack_start, (VALUE*)STACK_END);
+#endif
 #if defined(__human68k__) || defined(__mc68000__)
-    rb_gc_mark_locations((VALUE*)((char*)rb_gc_stack_start + 2),
-			 (VALUE*)((char*)STACK_END + 2));
+    rb_gc_mark_locations((VALUE*)((char*)STACK_END + 2),
+			 (VALUE*)((char*)rb_gc_stack_start + 2));
 #endif
     rb_gc_mark_threads();
 
@@ -1268,18 +1297,6 @@ rb_gc_start()
     return Qnil;
 }
 
-#if !defined(__human68k__)
-static int
-stack_growup_p(addr)
-    VALUE *addr;
-{
-    SET_STACK_END;
-
-    if (STACK_END > addr) return Qtrue;
-    return Qfalse;
-}
-#endif
-
 void
 Init_stack(addr)
     VALUE *addr;
@@ -1290,14 +1307,10 @@ Init_stack(addr)
 #else
     if (!addr) addr = (VALUE *)&addr;
     if (rb_gc_stack_start) {
-	if (stack_growup_p(addr)) {
-	    if (rb_gc_stack_start > addr)
-		rb_gc_stack_start = addr;
-	}
-	else {
-	    if (rb_gc_stack_start < addr)
-		rb_gc_stack_start = addr;
-	}
+	if (STACK_UPPER(&addr,
+			rb_gc_stack_start > --addr,
+			rb_gc_stack_start < ++addr))
+	    rb_gc_stack_start = addr;
 	return;
     }
     rb_gc_stack_start = addr;