signal.c: fix received_signal

* signal.c (received_signal): fix condition to define.
  [ruby-core:67032] [Bug #10629]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48920 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Mon Dec 22 14:08:31 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* signal.c (received_signal): fix condition to define.
+	  [ruby-core:67032] [Bug #10629]
+
 Sun Dec 21 10:51:51 2014  Masaki Suketa <masaki.suketa@nifty.ne.jp>
 
 	* test/win32ole/test_win32ole_event.rb: test_s_new_exception is

signal.c

@@ -743,10 +743,15 @@ rb_get_next_signal(void)
     return sig;
 }
 
+#if defined SIGSEGV || defined SIGBUS || defined SIGILL || defined SIGFPE
+static const char *received_signal;
+# define clear_received_signal() (void)(received_signal = 0)
+#else
+# define clear_received_signal() ((void)0)
+#endif
 
 #if defined(USE_SIGALTSTACK) || defined(_WIN32)
 NORETURN(void ruby_thread_stack_overflow(rb_thread_t *th));
-static const char *received_signal;
 # if !(defined(HAVE_UCONTEXT_H) && (defined __i386__ || defined __x86_64__ || defined __amd64__))
 # elif defined __linux__
 #   define USE_UCONTEXT_REG 1
@@ -793,7 +798,7 @@ check_stack_overflow(const uintptr_t addr, const ucontext_t *ctx)
 	     * place. */
 	    th->tag = th->tag->prev;
 	}
-	received_signal = 0;
+	clear_received_signal();
 	ruby_thread_stack_overflow(th);
     }
 }
@@ -804,7 +809,7 @@ check_stack_overflow(const void *addr)
     int ruby_stack_overflowed_p(const rb_thread_t *, const void *);
     rb_thread_t *th = ruby_current_thread;
     if (ruby_stack_overflowed_p(th, addr)) {
-	received_signal = 0;
+	clear_received_signal();
 	ruby_thread_stack_overflow(th);
     }
 }