diff --git a/ChangeLog b/ChangeLog
index ad1317e54e..97753c97f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Nov  8 17:35:53 2005  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
+
+	* intern.h, eval.c (rb_thread_signal_raise): costified.
+
+	* signal.c: cosmetic change.
+
 Tue Nov  8 15:32:27 2005  GOTOU Yuuzou  <gotoyuzo@notwork.org>
 
 	* lib/drb/ssl.rb (DRb::SSLConfig#accept): fixed typo.
diff --git a/eval.c b/eval.c
index d5048d9465..b98746e517 100644
--- a/eval.c
+++ b/eval.c
@@ -10014,7 +10014,7 @@ static VALUE th_raise_exception;
 static NODE *th_raise_node;
 static VALUE th_cmd;
 static int   th_sig, th_safe;
-static char *th_signm;
+static const char   *th_signm;
 
 #define RESTORE_NORMAL		1
 #define RESTORE_FATAL		2
@@ -12101,7 +12101,7 @@ rb_thread_interrupt(void)
 }
 
 void
-rb_thread_signal_raise(char *sig)
+rb_thread_signal_raise(const char *sig)
 {
     if (sig == 0) return;	/* should not happen */
     rb_thread_critical = 0;
@@ -12115,7 +12115,7 @@ rb_thread_signal_raise(char *sig)
 	    return;
 	}
     }
-    th_signm = sig;
+    th_signm = sig;	/* should be literal */
     curr_thread = main_thread;
     rb_thread_restore_context(curr_thread, RESTORE_SIGNAL);
 }
diff --git a/intern.h b/intern.h
index ec08a3f5fa..7c33d7c225 100644
--- a/intern.h
+++ b/intern.h
@@ -273,7 +273,7 @@ VALUE rb_thread_kill(VALUE);
 VALUE rb_thread_create(VALUE (*)(ANYARGS), void*);
 void rb_thread_interrupt(void);
 void rb_thread_trap_eval(VALUE, int, int);
-void rb_thread_signal_raise(char*);
+void rb_thread_signal_raise(const char*); /* should pass literal */
 void rb_thread_signal_exit(void);
 int rb_thread_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
 void rb_thread_wait_for(struct timeval);
diff --git a/signal.c b/signal.c
index 48820c0308..2bbf9e84b9 100644
--- a/signal.c
+++ b/signal.c
@@ -30,7 +30,7 @@
 #endif
 
 static struct signals {
-    char *signm;
+    const char *signm;
     int  signo;
 } siglist [] = {
     {"EXIT", 0},
@@ -169,7 +169,7 @@ static struct signals {
 };
 
 static int
-signm2signo(char *nm)
+signm2signo(const char *nm)
 {
     struct signals *sigs;
 
@@ -179,7 +179,7 @@ signm2signo(char *nm)
     return 0;
 }
 
-static char*
+static const char*
 signo2signm(int no)
 {
     struct signals *sigs;
@@ -325,9 +325,7 @@ typedef RETSIGTYPE (*sighandler_t)(int);
 
 #ifdef POSIX_SIGNAL
 static sighandler_t
-ruby_signal(signum, handler)
-    int signum;
-    sighandler_t handler;
+ruby_signal(int signum, sighandler_t handler)
 {
     struct sigaction sigact, old;
 
@@ -345,18 +343,14 @@ ruby_signal(signum, handler)
 }
 
 void
-posix_signal(signum, handler)
-    int signum;
-    sighandler_t handler;
+posix_signal(int signum, sighandler_t handler)
 {
     ruby_signal(signum, handler);
 }
 
 #ifdef HAVE_NATIVETHREAD
 static sighandler_t
-ruby_nativethread_signal(signum, handler)
-    int signum;
-    sighandler_t handler;
+ruby_nativethread_signal(int signum, sighandler_t handler)
 {
     sighandler_t old;
 
@@ -366,9 +360,7 @@ ruby_nativethread_signal(signum, handler)
 }
 
 void
-posix_nativethread_signal(signum, handler)
-    int signum;
-    sighandler_t handler;
+posix_nativethread_signal(int signum, sighandler_t handler)
 {
     ruby_nativethread_signal(signum, handler);
 }
@@ -445,7 +437,6 @@ sigsend_to_ruby_thread(int sig)
 }
 #endif
 
-static RETSIGTYPE sighandler(int);
 static RETSIGTYPE
 sighandler(int sig)
 {
@@ -707,8 +698,7 @@ trap(struct trap_arg *arg)
 
 #ifndef _WIN32
 static VALUE
-trap_ensure(arg)
-    struct trap_arg *arg;
+trap_ensure(struct trap_arg *arg)
 {
     /* enable interrupt */
 #ifdef HAVE_SIGPROCMASK