11 files changed, 40 insertions, 0 deletions
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 3fbb9a8883..041d33fd7d 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -971,6 +971,8 @@ BigDecimalCmp(VALUE self, VALUE r,char op)
     }
 
     rb_bug("Undefined operation in BigDecimalCmp()");
+
+    UNREACHABLE;
 }
 
 /* Returns True if the value is zero. */
diff --git a/ext/digest/digest.c b/ext/digest/digest.c
index 956f47ff78..4d185a8e5d 100644
--- a/ext/digest/digest.c
+++ b/ext/digest/digest.c
@@ -154,6 +154,8 @@ static VALUE
 rb_digest_instance_update(VALUE self, VALUE str)
 {
     rb_digest_instance_method_unimpl(self, "update");
+
+    UNREACHABLE;
 }
 
 /*
@@ -172,6 +174,8 @@ static VALUE
 rb_digest_instance_finish(VALUE self)
 {
     rb_digest_instance_method_unimpl(self, "finish");
+
+    UNREACHABLE;
 }
 
 /*
@@ -186,6 +190,8 @@ static VALUE
 rb_digest_instance_reset(VALUE self)
 {
     rb_digest_instance_method_unimpl(self, "reset");
+
+    UNREACHABLE;
 }
 
 /*
@@ -409,6 +415,8 @@ static VALUE
 rb_digest_instance_block_length(VALUE self)
 {
     rb_digest_instance_method_unimpl(self, "block_length");
+
+    UNREACHABLE;
 }
 
 /*
diff --git a/ext/dl/handle.c b/ext/dl/handle.c
index 2037ab5760..ef182e816f 100644
--- a/ext/dl/handle.c
+++ b/ext/dl/handle.c
@@ -78,6 +78,8 @@ rb_dlhandle_close(VALUE self)
 	return INT2NUM(ret);
     }
     rb_raise(rb_eDLError, "dlclose() called too many times");
+
+    UNREACHABLE;
 }
 
 VALUE
diff --git a/ext/fiddle/conversions.c b/ext/fiddle/conversions.c
index f2c1511778..d40ddc1f38 100644
--- a/ext/fiddle/conversions.c
+++ b/ext/fiddle/conversions.c
@@ -134,6 +134,8 @@ generic_to_value(VALUE rettype, fiddle_generic retval)
       default:
 	rb_raise(rb_eRuntimeError, "unknown type %d", type);
     }
+
+    UNREACHABLE;
 }
 
 /* vim: set noet sw=4 sts=4 */
diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index 9f1050f62d..cfcaf97ab5 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -700,6 +700,8 @@ static VALUE ossl_ec_key_dsa_verify_asn1(VALUE self, VALUE data, VALUE sig)
     }
 
     ossl_raise(eECError, "ECDSA_verify");
+
+    UNREACHABLE;
 }
 
 static void ossl_ec_group_free(ossl_ec_group *ec_group)
@@ -1349,6 +1351,8 @@ static VALUE ossl_ec_point_is_at_infinity(VALUE self)
     case 0: return Qfalse;
     default: ossl_raise(cEC_POINT, "EC_POINT_is_at_infinity");
     }
+
+    UNREACHABLE;
 }
 
 /*
@@ -1370,6 +1374,8 @@ static VALUE ossl_ec_point_is_on_curve(VALUE self)
     case 0: return Qfalse;
     default: ossl_raise(cEC_POINT, "EC_POINT_is_on_curve");
     }
+
+    UNREACHABLE;
 }
 
 /*
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index c55b7796f7..79941db1ee 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -1593,6 +1593,8 @@ ossl_ssl_session_reused(VALUE self)
     case 0:	return Qfalse;
     default:	ossl_raise(eSSLError, "SSL_session_reused");
     }
+
+    UNREACHABLE;
 }
 
 /*
diff --git a/ext/ripper/eventids2.c b/ext/ripper/eventids2.c
index 946978954a..18d2d2a28a 100644
--- a/ext/ripper/eventids2.c
+++ b/ext/ripper/eventids2.c
@@ -275,4 +275,6 @@ ripper_token2eventid(int tok)
         return ripper_id_CHAR;
     }
     rb_raise(rb_eRuntimeError, "[Ripper FATAL] unknown token %d", tok);
+
+    UNREACHABLE;
 }
diff --git a/ext/socket/raddrinfo.c b/ext/socket/raddrinfo.c
index a9a4535741..f71d0f9c65 100644
--- a/ext/socket/raddrinfo.c
+++ b/ext/socket/raddrinfo.c
@@ -2144,6 +2144,8 @@ rsock_io_socket_addrinfo(VALUE io, struct sockaddr *addr, socklen_t len)
       default:
         rb_raise(rb_eTypeError, "neither IO nor file descriptor");
     }
+
+    UNREACHABLE;
 }
 
 /*
diff --git a/ext/socket/socket.c b/ext/socket/socket.c
index 872dd65b85..d2177e505d 100644
--- a/ext/socket/socket.c
+++ b/ext/socket/socket.c
@@ -1334,6 +1334,8 @@ sock_s_getnameinfo(int argc, VALUE *argv)
   error_exit_name:
     if (res) freeaddrinfo(res);
     rsock_raise_socket_error("getnameinfo", error);
+
+    UNREACHABLE;
 }
 
 /*
diff --git a/ext/tk/tcltklib.c b/ext/tk/tcltklib.c
index e3c5ea0c79..02571d62fb 100644
--- a/ext/tk/tcltklib.c
+++ b/ext/tk/tcltklib.c
@@ -1407,6 +1407,8 @@ pending_exception_check0()
     } else {
         return 0;
     }
+
+    UNREACHABLE;
 }
 
 static int
@@ -1448,6 +1450,8 @@ pending_exception_check1(thr_crit_bup, ptr)
     } else {
         return 0;
     }
+
+    UNREACHABLE;
 }
 
 
@@ -7781,6 +7785,8 @@ ip_cancel_eval_core(interp, msg, flag)
 #if TCL_MAJOR_VERSION < 8 || (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION < 6)
     rb_raise(rb_eNotImpError,
 	     "cancel_eval is supported Tcl/Tk8.6 or later.");
+
+    UNREACHABLE;
 #else
     Tcl_Obj *msg_obj;
 
@@ -10014,6 +10020,8 @@ lib_get_reltype_name(self)
     default:
       rb_raise(rb_eRuntimeError, "tcltklib has invalid release type number");
     }
+
+    UNREACHABLE;
 }
 
 
@@ -10117,6 +10125,8 @@ create_dummy_encoding_for_tk_core(interp, name, error_mode)
       return Qnil;
     }
   }
+
+  UNREACHABLE;
 #else
     return name;
 #endif
diff --git a/ext/tk/tkutil/tkutil.c b/ext/tk/tkutil/tkutil.c
index 956c6737c9..0e256921ba 100644
--- a/ext/tk/tkutil/tkutil.c
+++ b/ext/tk/tkutil/tkutil.c
@@ -800,6 +800,8 @@ tk_hash_kv(argc, argv, self)
         }
         rb_raise(rb_eArgError, "Hash is expected for 1st argument");
     }
+
+    UNREACHABLE;
 }
 
 static VALUE