diff --git a/ChangeLog b/ChangeLog
index 4b62941cb8..9c485ae292 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Jun  7 21:37:58 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (rb_f_open), re.c (rb_reg_search), transcode.c (str_transcode):
+	  suppress warnings.
+
+	* util.c (quorem, rv_alloc, nrv_alloc): only used in dtoa().
+
 Sat Jun  7 16:06:14 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (CFLAGS, CXXFLAGS): append default flags.
diff --git a/io.c b/io.c
index 625766be6a..40f9abfd21 100644
--- a/io.c
+++ b/io.c
@@ -4215,7 +4215,7 @@ rb_io_s_sysopen(int argc, VALUE *argv)
 static VALUE
 rb_f_open(int argc, VALUE *argv)
 {
-    ID to_open;
+    ID to_open = 0;
     int redirect = Qfalse;
 
     if (argc >= 1) {
diff --git a/re.c b/re.c
index 8ce5e89c28..51809f5ee1 100644
--- a/re.c
+++ b/re.c
@@ -1279,7 +1279,7 @@ rb_reg_search(VALUE re, VALUE str, int pos, int reverse)
 {
     int result;
     VALUE match;
-    struct re_registers *regs, regi;
+    struct re_registers regi, *regs = &regi;
     char *range = RSTRING_PTR(str);
     regex_t *reg0 = RREGEXP(re)->ptr, *reg;
     int busy = FL_TEST(re, REG_BUSY);
@@ -1301,7 +1301,6 @@ rb_reg_search(VALUE re, VALUE str, int pos, int reverse)
 	}
     }
     if (NIL_P(match)) {
-	regs = &regi;
 	MEMZERO(regs, struct re_registers, 1);
     }
     FL_SET(re, REG_BUSY);
diff --git a/transcode.c b/transcode.c
index f58c683357..02c82c5c3b 100644
--- a/transcode.c
+++ b/transcode.c
@@ -309,7 +309,7 @@ str_transcode(int argc, VALUE *argv, VALUE *self)
 	return -1;
     }
 
-    while (!final_encoding) { /* loop for multistep transcoding */
+    do { /* loop for multistep transcoding */
 	/* later, maybe use smaller intermediate strings for very long strings */
 	if (!(my_transcoder = transcode_dispatch(from_e, to_e))) {
 	    rb_raise(rb_eArgError, "transcoding not supported (from %s to %s)", from_e, to_e);
@@ -372,7 +372,7 @@ str_transcode(int argc, VALUE *argv, VALUE *self)
 	    from_e = my_transcoder->to_encoding;
 	    str = dest;
 	}
-    }
+    } while (!final_encoding);
     /* set encoding */
     if (!to_enc) {
 	to_encidx = rb_define_dummy_encoding(to_e);
diff --git a/util.c b/util.c
index 6c5f498932..125b99103e 100644
--- a/util.c
+++ b/util.c
@@ -3067,6 +3067,7 @@ ret:
     return sign ? -dval(rv) : dval(rv);
 }
 
+#if 0  /* unused right now */
 static int
 quorem(Bigint *b, Bigint *S)
 {
@@ -3177,11 +3178,13 @@ quorem(Bigint *b, Bigint *S)
     }
     return q;
 }
+#endif
 
 #ifndef MULTIPLE_THREADS
 static char *dtoa_result;
 #endif
 
+#if 0  /* unused right now */
 static char *
 rv_alloc(int i)
 {
@@ -3212,6 +3215,7 @@ nrv_alloc(const char *s, char **rve, int n)
         *rve = t;
     return rv;
 }
+#endif
 
 /* freedtoa(s) must be used to free values s returned by dtoa
  * when MULTIPLE_THREADS is #defined.  It should be used in all cases,