* vm_core.h: Introduce UNINITIALIZED_VAR() macro.

* thread.c (do_select): Use UNINITIALIZED_VAR() instead FAKE_FD_ZERO().
	  Also, remove FAKE_FD_ZERO completely. [Feature #3018]




git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Tue Apr  6 23:01:35 2010  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* vm_core.h: Introduce UNINITIALIZED_VAR() macro.
+	* thread.c (do_select): Use UNINITIALIZED_VAR() instead FAKE_FD_ZERO().
+	  Also, remove FAKE_FD_ZERO completely. [Feature #3018]
+
 Tue Apr  6 21:55:25 2010  Tanaka Akira  <akr@fsij.org>
 
 	* configure.in: test localtime(3) overflow.  [ruby-dev:40910]

thread.c

@@ -2415,12 +2415,9 @@ do_select(int n, fd_set *read, fd_set *write, fd_set *except,
 	  struct timeval *timeout)
 {
     int result, lerrno;
-    fd_set orig_read, orig_write, orig_except;
-#if defined __GNUC__ && defined __x86_64__
-#define FAKE_FD_ZERO(f) (*(int *)&(f)=0) /* suppress lots of warnings */
-#else
-#define FAKE_FD_ZERO(f) ((void)0)
-#endif
+    fd_set UNINITIALIZED_VAR(orig_read);
+    fd_set UNINITIALIZED_VAR(orig_write);
+    fd_set UNINITIALIZED_VAR(orig_except);
 
 #ifndef linux
     double limit = 0;
@@ -2442,11 +2439,9 @@ do_select(int n, fd_set *read, fd_set *write, fd_set *except,
     }
 #endif
 
-    if (read) orig_read = *read; else FAKE_FD_ZERO(orig_read);
-    if (write) orig_write = *write; else FAKE_FD_ZERO(orig_write);
-    if (except) orig_except = *except; else FAKE_FD_ZERO(orig_except);
-
-#undef FAKE_FD_ZERO
+    if (read) orig_read = *read;
+    if (write) orig_write = *write;
+    if (except) orig_except = *except;
 
   retry:
     lerrno = 0;

vm_core.h

@@ -106,6 +106,12 @@
 #define UNLIKELY(x) (x)
 #endif /* __GNUC__ >= 3 */
 
+#if __GNUC__ >= 3
+#define UNINITIALIZED_VAR(x) x = x
+#else
+#define UNINITIALIZED_VAR(x) x
+#endif
+
 typedef unsigned long rb_num_t;
 
 /* iseq data type */