file clean-up on std.c

Makefile.in

@@ -165,8 +165,8 @@ am__DIST_COMMON = $(srcdir)/Makefile.in $(top_srcdir)/ac/ar-lib \
 	$(top_srcdir)/ac/compile $(top_srcdir)/ac/config.guess \
 	$(top_srcdir)/ac/config.sub $(top_srcdir)/ac/install-sh \
 	$(top_srcdir)/ac/ltmain.sh $(top_srcdir)/ac/missing ac/ar-lib \
-	ac/compile ac/config.guess ac/config.sub ac/install-sh \
-	ac/ltmain.sh ac/missing
+	ac/compile ac/config.guess ac/config.sub ac/depcomp \
+	ac/install-sh ac/ltmain.sh ac/missing
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)

configure

@@ -18190,6 +18190,23 @@ MOO_PROJECT_AUTHOR="${PACKAGE_BUGREPORT}"
 MOO_PROJECT_URL="${PACKAGE_URL}"
 
 
+if test `expr " $0" : " '.*"` = 0; then
+	moo_configure_cmd="'$0'"
+else
+	moo_configure_cmd="$0"
+fi
+
+
+cat >>confdefs.h <<_ACEOF
+#define MOO_CONFIGURE_ARGS "$ac_configure_args"
+_ACEOF
+
+
+cat >>confdefs.h <<_ACEOF
+#define MOO_CONFIGURE_CMD "$moo_configure_cmd"
+_ACEOF
+
+
 ac_config_files="$ac_config_files Makefile tools/Makefile lib/Makefile mod/Makefile bin/Makefile t/Makefile wasm/Makefile"
 
 cat >confcache <<\_ACEOF

configure.ac

@@ -842,6 +842,16 @@ dnl ====  subsititution of some key items ====
 AC_SUBST(MOO_PROJECT_AUTHOR, "${PACKAGE_BUGREPORT}")
 AC_SUBST(MOO_PROJECT_URL, "${PACKAGE_URL}")
 
+dnl === configure arguments
+if test `expr " [$]0" : " '.*"` = 0; then
+	moo_configure_cmd="'[$]0'"
+else
+	moo_configure_cmd="[$]0"
+fi
+
+AC_DEFINE_UNQUOTED(MOO_CONFIGURE_ARGS, ["$ac_configure_args"], [configure arguments])
+AC_DEFINE_UNQUOTED(MOO_CONFIGURE_CMD, ["$moo_configure_cmd"], [configure command])
+
 AC_CONFIG_FILES([
 	Makefile 
 	tools/Makefile 

kernel/System.moo

@@ -166,28 +166,35 @@ class System(Apex)
 					// TODO: Do i have to protected this in an exception handler???
 					//TODO: Execute Handler for signo.
 
-					System logNl: "Interrupt dectected - signal no - " & signo asString.
+					System logNl: "Interrupt detected - signal no - " & signo asString.
 
+//System logNl: "WWWWWWWWWWWWWWWWWWWWWWWWW ".
 					// user-defined signal handler is not allowed for 16rFF
 					if (signo == 16rFF) { goto done }. 
+//System logNl: "OHHHHHHHHHHHHHH ".
 
 					ifnot (self.shr isEmpty)
 					{
+//System logNl: "About to execute handler for the signal detected - " & signo asString.
 						self.shr do: [ :handler | handler value: signo ].
 					}
 					else
 					{
+//System logNl: "Jumping to done detected - signal no - " & signo asString.
 						if (signo == 2) { goto done }.
 					}.
 				}.
+//System logNl: "Waiting for signal on os_intr_sem...".
 				os_intr_sem wait.
 			}.
 		done:
+//System logNl: "Jumped to done detected - signal no - " & signo asString.
 			nil.
 		]
 		ensure: [
 			| pid proc oldps |
 
+//System logNl: "Aborting signal handler......".
 			// stop subscribing to signals.
 			os_intr_sem signal.
 			os_intr_sem unsignal.

lib/bigint.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

lib/comp.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

lib/debug.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

lib/decode.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
@@ -28,19 +28,10 @@
 
 #define DECODE_LOG_MASK (MOO_LOG_MNEMONIC | MOO_LOG_DEBUG)
 
-#if defined(MOO_BUILD_RELEASE)
-	/* get rid of instruction logging regardless of the log mask
-	 * in the release build */
-#	define LOG_INST_0(moo,fmt)
-#	define LOG_INST_1(moo,fmt,a1)
-#	define LOG_INST_2(moo,fmt,a1,a2)
-#	define LOG_INST_3(moo,fmt,a1,a2,a3)
-#else
-#	define LOG_INST_0(moo,fmt) MOO_LOG1(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer)
-#	define LOG_INST_1(moo,fmt,a1) MOO_LOG2(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1)
-#	define LOG_INST_2(moo,fmt,a1,a2) MOO_LOG3(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1, a2)
-#	define LOG_INST_3(moo,fmt,a1,a2,a3) MOO_LOG4(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1, a2, a3)
-#endif
+#define LOG_INST_0(moo,fmt) MOO_LOG1(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer)
+#define LOG_INST_1(moo,fmt,a1) MOO_LOG2(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1)
+#define LOG_INST_2(moo,fmt,a1,a2) MOO_LOG3(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1, a2)
+#define LOG_INST_3(moo,fmt,a1,a2,a3) MOO_LOG4(moo, DECODE_LOG_MASK, " %06zd " fmt "\n", fetched_instruction_pointer, a1, a2, a3)
 
 #define FETCH_BYTE_CODE(moo) (cdptr[ip++])
 #define FETCH_BYTE_CODE_TO(moo,v_oow) (v_oow = FETCH_BYTE_CODE(moo))

lib/exec.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
@@ -135,6 +135,7 @@ static MOO_INLINE const char* proc_state_to_string (int state)
 
 static int delete_sem_from_sem_io_tuple (moo_t* moo, moo_oop_semaphore_t sem, int force);
 static void signal_io_semaphore (moo_t* moo, moo_ooi_t io_handle, moo_ooi_t mask);
+static void terminate_all_processes (moo_t* moo);
 static int send_message (moo_t* moo, moo_oop_char_t selector, moo_ooi_t nargs, int to_super);
 
 /* ------------------------------------------------------------------------- */
@@ -165,6 +166,24 @@ static MOO_INLINE void vm_cleanup (moo_t* moo)
 /* TODO: clean up semaphores being waited on 
 	MOO_ASSERT (moo, moo->sem_io_wait_count == 0); */
 
+	if (moo->processor->total_count != MOO_SMOOI_TO_OOP(0))
+	{
+		/* the stock kernel code is supposed to stop all processes.
+		 * if the code reaches here, the kernel code must be buggy */
+		MOO_LOG3 (moo, MOO_LOG_WARN, "Warning - non-zero number of processes upon VM clean-up - total: %zd runnable: %zd suspended: %zd\n", 
+			(moo_ooi_t)MOO_OOP_TO_SMOOI(moo->processor->total_count),
+			(moo_ooi_t)MOO_OOP_TO_SMOOI(moo->processor->runnable.count),
+			(moo_ooi_t)MOO_OOP_TO_SMOOI(moo->processor->suspended.count));
+		
+		MOO_LOG0 (moo, MOO_LOG_WARN, "Warning - terminating all residue processes\n");
+		terminate_all_processes (moo);
+	}
+
+	MOO_ASSERT (moo, moo->processor->active == moo->nil_process);
+	MOO_ASSERT (moo, MOO_OOP_TO_SMOOI(moo->processor->total_count) == 0);
+	MOO_ASSERT (moo, MOO_OOP_TO_SMOOI(moo->processor->runnable.count) == 0);
+	MOO_ASSERT (moo, MOO_OOP_TO_SMOOI(moo->processor->suspended.count) == 0);
+
 	for (i = 0; i < moo->sem_io_map_capa;)
 	{
 		moo_ooi_t sem_io_index;
@@ -778,6 +797,22 @@ static void terminate_process (moo_t* moo, moo_oop_process_t proc)
 #endif
 }
 
+static void terminate_all_processes (moo_t* moo)
+{
+	while (MOO_OOP_TO_SMOOI(moo->processor->suspended.count) > 0)
+	{
+		terminate_process (moo, moo->processor->suspended.first);
+	}
+
+	while (MOO_OOP_TO_SMOOI(moo->processor->runnable.count) > 0)
+	{
+		terminate_process (moo, moo->processor->runnable.first);
+	}
+
+	MOO_ASSERT (moo, MOO_OOP_TO_SMOOI(moo->processor->total_count) == 0);
+	MOO_ASSERT (moo, moo->processor->active == moo->nil_process);
+}
+
 static void resume_process (moo_t* moo, moo_oop_process_t proc)
 {
 	if (proc->state == MOO_SMOOI_TO_OOP(PROC_STATE_SUSPENDED))
@@ -1959,11 +1994,11 @@ void moo_clearmethodcache (moo_t* moo)
 
 static int start_initial_process_and_context (moo_t* moo, const moo_oocs_t* objname, const moo_oocs_t* mthname)
 {
-	/* the initial context is a fake context. if objname is 'Stix' and
-	 * mthname is 'main', this function emulates message sending 'Stix main'.
+	/* the initial context is a fake context. if objname is 'Moo' and
+	 * mthname is 'main', this function emulates message sending 'Moo main'.
 	 * it should emulate the following logical byte-code sequences:
 	 *
-	 *    push Stix
+	 *    push Moo
 	 *    send #main
 	 */
 	moo_oop_context_t ctx;
@@ -4868,7 +4903,7 @@ static int send_message (moo_t* moo, moo_oop_char_t selector, moo_ooi_t nargs, i
 	MOO_ASSERT (moo, MOO_OBJ_GET_FLAGS_TYPE(selector) == MOO_OBJ_TYPE_CHAR);
 	MOO_ASSERT (moo, MOO_CLASSOF(moo, selector) == moo->_symbol);
 
-	receiver = MOO_STACK_GET(moo, moo->sp - nargs);
+	receiver = MOO_STACK_GETRCV(moo, nargs);
 
 #if defined(MOO_PROFILE_VM)
 	moo->stat.message_sends++;

lib/fmt.c

@@ -839,7 +839,7 @@ static int fmt_outv (moo_fmtout_t* fmtout, va_list ap)
 			/* zeropad must not take effect for 's' */
 			if (flagc & FLAGC_ZEROPAD) padc = ' ';
 			if (lm_flag & LF_H) goto lowercase_s;
-		#if defined(MOO_OOCH_IS_UCH)
+		#if defined(MOO_OOCH_IS_BCH)
 			if (lm_flag & LF_J) goto lowercase_s;
 		#endif
 		uppercase_s:
@@ -1223,7 +1223,7 @@ static int fmt_outv (moo_fmtout_t* fmtout, va_list ap)
 			sign = 0;
 			if (lm_flag & LF_J)
 			{
-			#if 0 && defined(__GNUC__) && \
+			#if 1 && !defined(__clang__) && defined(__GNUC__) && \
 			    (MOO_SIZEOF_UINTMAX_T > MOO_SIZEOF_OOW_T) && \
 			    (MOO_SIZEOF_UINTMAX_T != MOO_SIZEOF_LONG_LONG) && \
 			    (MOO_SIZEOF_UINTMAX_T != MOO_SIZEOF_LONG)
@@ -1265,7 +1265,7 @@ static int fmt_outv (moo_fmtout_t* fmtout, va_list ap)
 		handle_sign:
 			if (lm_flag & LF_J)
 			{
-			#if 0 && defined(__GNUC__) && \
+			#if 1 && !defined(__clang__) && defined(__GNUC__) && \
 			    (MOO_SIZEOF_INTMAX_T > MOO_SIZEOF_OOI_T) && \
 			    (MOO_SIZEOF_UINTMAX_T != MOO_SIZEOF_LONG_LONG) && \
 			    (MOO_SIZEOF_UINTMAX_T != MOO_SIZEOF_LONG)

lib/moo-cfg.h.in

@@ -339,6 +339,12 @@
 /* build release/debug */
 #undef MOO_BUILD_RELEASE
 
+/* configure arguments */
+#undef MOO_CONFIGURE_ARGS
+
+/* configure command */
+#undef MOO_CONFIGURE_CMD
+
 /* enable dynamic module capability */
 #undef MOO_ENABLE_DYNAMIC_MODULE
 

lib/moo-utl.h

@@ -663,12 +663,6 @@ moo_oow_t moo_byte_to_bcstr (
 
 /* ------------------------------------------------------------------------- */
 
-MOO_EXPORT int moo_get_ucwidth (
-	moo_uch_t uc
-);
-
-/* ------------------------------------------------------------------------- */
-
 #if defined(MOO_OOCH_IS_UCH)
 #	define moo_conv_oocstr_to_bcstr_with_cmgr(oocs,oocslen,bcs,bcslen,cmgr) moo_conv_ucstr_to_bcstr_with_cmgr(oocs,oocslen,bcs,bcslen,cmgr)
 #	define moo_conv_oochars_to_bchars_with_cmgr(oocs,oocslen,bcs,bcslen,cmgr) moo_conv_uchars_to_bchars_with_cmgr(oocs,oocslen,bcs,bcslen,cmgr)

lib/moo.h

@@ -1105,26 +1105,26 @@ struct moo_dbgi_method_t
 
 enum moo_log_mask_t
 {
-	MOO_LOG_DEBUG      = (1u << 0),
-	MOO_LOG_INFO       = (1u << 1),
-	MOO_LOG_WARN       = (1u << 2),
-	MOO_LOG_ERROR      = (1u << 3),
-	MOO_LOG_FATAL      = (1u << 4),
+	MOO_LOG_DEBUG      = ((moo_bitmask_t)1 << 0),
+	MOO_LOG_INFO       = ((moo_bitmask_t)1 << 1),
+	MOO_LOG_WARN       = ((moo_bitmask_t)1 << 2),
+	MOO_LOG_ERROR      = ((moo_bitmask_t)1 << 3),
+	MOO_LOG_FATAL      = ((moo_bitmask_t)1 << 4),
 
-	MOO_LOG_UNTYPED    = (1u << 6), /* only to be used by MOO_DEBUGx() and MOO_INFOx() */
-	MOO_LOG_COMPILER   = (1u << 7),
-	MOO_LOG_VM         = (1u << 8),
-	MOO_LOG_MNEMONIC   = (1u << 9), /* bytecode mnemonic */
-	MOO_LOG_GC         = (1u << 10),
-	MOO_LOG_IC         = (1u << 11), /* instruction cycle, fetch-decode-execute */
-	MOO_LOG_PRIMITIVE  = (1u << 12),
-	MOO_LOG_APP        = (1u << 13), /* moo applications, set by moo logging primitive */
+	MOO_LOG_UNTYPED    = ((moo_bitmask_t)1 << 6), /* only to be used by MOO_DEBUGx() and MOO_INFOx() */
+	MOO_LOG_COMPILER   = ((moo_bitmask_t)1 << 7),
+	MOO_LOG_VM         = ((moo_bitmask_t)1 << 8),
+	MOO_LOG_MNEMONIC   = ((moo_bitmask_t)1 << 9), /* bytecode mnemonic */
+	MOO_LOG_GC         = ((moo_bitmask_t)1 << 10),
+	MOO_LOG_IC         = ((moo_bitmask_t)1 << 11), /* instruction cycle, fetch-decode-execute */
+	MOO_LOG_PRIMITIVE  = ((moo_bitmask_t)1 << 12),
+	MOO_LOG_APP        = ((moo_bitmask_t)1 << 13), /* moo applications, set by moo logging primitive */
 
 	MOO_LOG_ALL_LEVELS = (MOO_LOG_DEBUG  | MOO_LOG_INFO | MOO_LOG_WARN | MOO_LOG_ERROR | MOO_LOG_FATAL),
 	MOO_LOG_ALL_TYPES  = (MOO_LOG_UNTYPED | MOO_LOG_COMPILER | MOO_LOG_VM | MOO_LOG_MNEMONIC | MOO_LOG_GC | MOO_LOG_IC | MOO_LOG_PRIMITIVE | MOO_LOG_APP),
 
-	MOO_LOG_STDOUT     = (1u << 14), /* write log messages to stdout without timestamp. MOO_LOG_STDOUT wins over MOO_LOG_STDERR. */
-	MOO_LOG_STDERR     = (1u << 15)  /* write log messages to stderr without timestamp. */
+	MOO_LOG_STDOUT     = ((moo_bitmask_t)1 << 14), /* write log messages to stdout without timestamp. MOO_LOG_STDOUT wins over MOO_LOG_STDERR. */
+	MOO_LOG_STDERR     = ((moo_bitmask_t)1 << 15)  /* write log messages to stderr without timestamp. */
 };
 typedef enum moo_log_mask_t moo_log_mask_t;
 

lib/pack1.h

@@ -24,7 +24,10 @@
     THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#if defined(__GNUC__)
+
+#if defined(__GNUC__) && (__GNUC__ >= 4)
+#	pragma pack(push,1)
+#elif defined(__GNUC__)
 #	pragma pack(1)
 #elif defined(__HP_aCC) || defined(__HP_cc)
 #	pragma PACK 1

lib/pf-basic.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

lib/pf-sys.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

lib/pf-utf8.c

@@ -13,7 +13,7 @@
        documentation and/or other materials provided with the distribution.
 
     THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
-    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WAfRRANTIES
+    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT