From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Tue, 10 Apr 2007 21:38:30 +0000 (-0000)
Subject: make a few struct bb_applet members conditional
X-Git-Tag: 1_6_0~191
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=335b63d8d1876ce4e172ebcc9d64544785682244;p=oweals%2Fbusybox.git

make a few struct bb_applet members conditional
rename sllep_and_die -> xfunc_die
make fflush_stdout_and_exit NOFORK-safe
fix some buglets found by randomconfig
---

diff --git a/applets/applets.c b/applets/applets.c
index 66f2b821d..3441a7886 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -43,13 +43,13 @@ static const char usage_messages[] =
 #define usage_messages 0
 #endif /* SHOW_USAGE */
 
-/* Define struct BB_applet applets[] */
+/* Define struct bb_applet applets[] */
 #include "applets.h"
 /* The -1 arises because of the {0,NULL,0,-1} entry. */
-const unsigned short NUM_APPLETS = sizeof(applets) / sizeof(struct BB_applet) - 1;
+const unsigned short NUM_APPLETS = sizeof(applets) / sizeof(applets[0]) - 1;
 
 
-const struct BB_applet *current_applet;
+const struct bb_applet *current_applet;
 const char *applet_name ATTRIBUTE_EXTERNALLY_VISIBLE;
 #ifdef BB_NOMMU
 bool re_execed;
@@ -61,7 +61,7 @@ bool re_execed;
 
 /* applets[] is const, so we have to define this "override" structure */
 static struct BB_suid_config {
-	const struct BB_applet *m_applet;
+	const struct bb_applet *m_applet;
 	uid_t m_uid;
 	gid_t m_gid;
 	mode_t m_mode;
@@ -130,7 +130,7 @@ static void parse_config_file(void)
 {
 	struct BB_suid_config *sct_head;
 	struct BB_suid_config *sct;
-	const struct BB_applet *applet;
+	const struct bb_applet *applet;
 	FILE *f;
 	const char *errmsg;
 	char *s;
@@ -329,7 +329,7 @@ static void parse_config_file(void)
 
 
 #if ENABLE_FEATURE_SUID
-static void check_suid(const struct BB_applet *applet)
+static void check_suid(const struct bb_applet *applet)
 {
 	uid_t ruid = getuid();               /* real [ug]id */
 	uid_t rgid = getgid();
@@ -464,45 +464,42 @@ void bb_show_usage(void)
 					applet_name, usage_string);
 	}
 
-	sleep_and_die();
+	xfunc_die();
 }
 
 
 static int applet_name_compare(const void *name, const void *vapplet)
 {
-	const struct BB_applet *applet = vapplet;
+	const struct bb_applet *applet = vapplet;
 
 	return strcmp(name, applet->name);
 }
 
-const struct BB_applet *find_applet_by_name(const char *name)
+const struct bb_applet *find_applet_by_name(const char *name)
 {
 	/* Do a binary search to find the applet entry given the name. */
-	return bsearch(name, applets, NUM_APPLETS, sizeof(struct BB_applet),
+	return bsearch(name, applets, NUM_APPLETS, sizeof(applets[0]),
 				applet_name_compare);
 }
 
 
 #if ENABLE_FEATURE_INSTALLER
-/*
- * directory table
- *		this should be consistent w/ the enum, busybox.h::Location,
- *		or else...
- */
-static const char usr_bin [] = "/usr/bin";
-static const char usr_sbin[] = "/usr/sbin";
-
-static const char *const install_dir[] = {
-	&usr_bin [8], /* "", equivalent to "/" for concat_path_file() */
-	&usr_bin [4], /* "/bin" */
-	&usr_sbin[4], /* "/sbin" */
-	usr_bin,
-	usr_sbin
-};
-
 /* create (sym)links for each applet */
 static void install_links(const char *busybox, int use_symbolic_links)
 {
+	/* directory table
+	 * this should be consistent w/ the enum,
+	 * busybox.h::bb_install_loc_t, or else... */
+	static const char usr_bin [] = "/usr/bin";
+	static const char usr_sbin[] = "/usr/sbin";
+	static const char *const install_dir[] = {
+		&usr_bin [8], /* "", equivalent to "/" for concat_path_file() */
+		&usr_bin [4], /* "/bin" */
+		&usr_sbin[4], /* "/sbin" */
+		usr_bin,
+		usr_sbin
+	};
+
 	int (*lf)(const char *, const char *) = link;
 	char *fpc;
 	int i;
@@ -513,7 +510,7 @@ static void install_links(const char *busybox, int use_symbolic_links)
 
 	for (i = 0; applets[i].name != NULL; i++) {
 		fpc = concat_path_file(
-				install_dir[applets[i].location],
+				install_dir[applets[i].install_loc],
 				applets[i].name);
 		rc = lf(busybox, fpc);
 		if (rc != 0 && errno != EEXIST) {
@@ -557,7 +554,7 @@ static int busybox_main(int argc, char **argv)
 			applet_name = argv[2];
 			run_applet_by_name(applet_name, 2, argv);
 		} else {
-			const struct BB_applet *a;
+			const struct bb_applet *a;
 			int col, output_width;
 
 			output_width = 80 - sizeof("start-stop-daemon, ") - 8;
diff --git a/archival/libunarchive/Kbuild b/archival/libunarchive/Kbuild
index 010043c4c..412a2332d 100644
--- a/archival/libunarchive/Kbuild
+++ b/archival/libunarchive/Kbuild
@@ -35,12 +35,15 @@ DPKG_FILES:= \
 	get_header_tar.o \
 	filter_accept_list_reassign.o
 
-# open_transformer uses fork. Compile it only if absolutely necessary
+# open_transformer uses fork(). Compile it only if absolutely necessary
 lib-$(CONFIG_RPM)                       += open_transformer.o
 lib-$(CONFIG_FEATURE_TAR_BZIP2)	        += open_transformer.o
 lib-$(CONFIG_FEATURE_TAR_LZMA)	        += open_transformer.o
 lib-$(CONFIG_FEATURE_TAR_GZIP)		+= open_transformer.o
 lib-$(CONFIG_FEATURE_TAR_COMPRESS)	+= open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_GZ)	+= open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_BZ2)	+= open_transformer.o
+lib-$(CONFIG_FEATURE_DEB_TAR_LZMA)	+= open_transformer.o
 
 lib-$(CONFIG_AR)			+= get_header_ar.o unpack_ar_archive.o
 lib-$(CONFIG_BUNZIP2)			+= decompress_bunzip2.o
diff --git a/coreutils/cmp.c b/coreutils/cmp.c
index c70f8822d..80fab0b90 100644
--- a/coreutils/cmp.c
+++ b/coreutils/cmp.c
@@ -23,14 +23,14 @@
 
 #include "busybox.h"
 
-static FILE *cmp_xfopen_input(const char * const filename)
+static FILE *cmp_xfopen_input(const char *filename)
 {
 	FILE *fp;
 
 	fp = fopen_or_warn_stdin(filename);
 	if (fp)
 		return fp;
-	sleep_and_die();	/* We already output an error message. */
+	xfunc_die();	/* We already output an error message. */
 }
 
 static const char fmt_eof[] = "cmp: EOF on %s\n";
diff --git a/coreutils/echo.c b/coreutils/echo.c
index 2ee5002ba..2de19c2e3 100644
--- a/coreutils/echo.c
+++ b/coreutils/echo.c
@@ -107,7 +107,9 @@ int bb_echo(char **argv)
 		putchar(' ');
 	}
 
+#if ENABLE_FEATURE_FANCY_ECHO
  newline_ret:
+#endif
 	if (nflag) {
 		putchar('\n');
 	}
diff --git a/include/applets.h b/include/applets.h
index b59d33183..d05299b69 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -52,12 +52,12 @@ s     - suid type:
 # define APPLET_NOFORK(name,main,l,s,name2)  LINK l name
 
 #else
-  const struct BB_applet applets[] = { /*    name,main,location,need_suid */
-# define APPLET(name,l,s)                    {#name,name##_main,l,s},
-# define APPLET_NOUSAGE(name,main,l,s)       {#name,main##_main,l,s},
-# define APPLET_ODDNAME(name,main,l,s,name2) {#name,main##_main,l,s},
-# define APPLET_NOEXEC(name,main,l,s,name2)  {#name,main##_main,l,s,1},
-# define APPLET_NOFORK(name,main,l,s,name2)  {#name,main##_main,l,s,1,1},
+  const struct bb_applet applets[] = { /*    name, main, location, need_suid */
+# define APPLET(name,l,s)                    { #name, name##_main USE_FEATURE_INSTALLER(,l) USE_FEATURE_SUID(,s) },
+# define APPLET_NOUSAGE(name,main,l,s)       { #name, main##_main USE_FEATURE_INSTALLER(,l) USE_FEATURE_SUID(,s) },
+# define APPLET_ODDNAME(name,main,l,s,name2) { #name, main##_main USE_FEATURE_INSTALLER(,l) USE_FEATURE_SUID(,s) },
+# define APPLET_NOEXEC(name,main,l,s,name2)  { #name, main##_main USE_FEATURE_INSTALLER(,l) USE_FEATURE_SUID(,s) USE_FEATURE_EXEC_PREFER_APPLETS(,1) },
+# define APPLET_NOFORK(name,main,l,s,name2)  { #name, main##_main USE_FEATURE_INSTALLER(,l) USE_FEATURE_SUID(,s) USE_FEATURE_EXEC_PREFER_APPLETS(,1 ,1) },
 #endif
 
 #if ENABLE_INSTALL_NO_USR
@@ -355,7 +355,7 @@ USE_GUNZIP(APPLET_ODDNAME(zcat, gunzip, _BB_DIR_BIN, _BB_SUID_NEVER, zcat))
 USE_ZCIP(APPLET(zcip, _BB_DIR_SBIN, _BB_SUID_NEVER))
 
 #if !defined(PROTOTYPES) && !defined(MAKE_USAGE)
-	{ 0, NULL, 0, 0 }
+	{ NULL }
 };
 #endif
 
diff --git a/include/busybox.h b/include/busybox.h
index 6f4808778..380de9ab8 100644
--- a/include/busybox.h
+++ b/include/busybox.h
@@ -9,26 +9,35 @@
 
 #include "libbb.h"
 
+#if ENABLE_FEATURE_INSTALLER
 /* order matters: used as index into "install_dir[]" in busybox.c */
-enum Location {
+typedef enum bb_install_loc_t {
 	_BB_DIR_ROOT = 0,
 	_BB_DIR_BIN,
 	_BB_DIR_SBIN,
 	_BB_DIR_USR_BIN,
 	_BB_DIR_USR_SBIN
-};
+} bb_install_loc_t;
+#endif
 
-enum SUIDRoot {
+#if ENABLE_FEATURE_SUID
+typedef enum bb_suid_t {
 	_BB_SUID_NEVER = 0,
 	_BB_SUID_MAYBE,
 	_BB_SUID_ALWAYS
-};
+} bb_suid_t;
+#endif
 
-struct BB_applet {
+struct bb_applet {
 	const char *name;
 	int (*main) (int argc, char **argv);
-	__extension__ enum Location location:8;
-	__extension__ enum SUIDRoot need_suid:8;
+#if ENABLE_FEATURE_INSTALLER
+	__extension__ enum bb_install_loc_t install_loc:8;
+#endif
+#if ENABLE_FEATURE_SUID
+	__extension__ enum bb_suid_t need_suid:8;
+#endif
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
 	/* true if instead if fork(); exec("applet"); waitpid();
 	 * one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
 	unsigned char noexec;
@@ -36,10 +45,11 @@ struct BB_applet {
 	/* true if instead if fork(); exec("applet"); waitpid();
 	 * one can simply call applet_main(argc,argv); */
 	unsigned char nofork;
+#endif
 };
 
 /* Defined in applet.c */
-extern const struct BB_applet applets[];
+extern const struct bb_applet applets[];
 extern const unsigned short NUM_APPLETS;
 
 #endif	/* _BB_INTERNAL_H_ */
diff --git a/include/libbb.h b/include/libbb.h
index 3919524bc..6fff441c5 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -608,7 +608,7 @@ llist_t *llist_rev(llist_t *list);
 int write_pidfile(const char *path);
 #define remove_pidfile(f) ((void)unlink(f))
 #else
-#define write_pidfile(f)  1
+#define write_pidfile(f)  TRUE
 #define remove_pidfile(f) ((void)0)
 #endif
 
@@ -623,7 +623,7 @@ extern smallint logmode;
 extern int die_sleep;
 extern int xfunc_error_retval;
 extern jmp_buf die_jmp;
-extern void sleep_and_die(void) ATTRIBUTE_NORETURN;
+extern void xfunc_die(void) ATTRIBUTE_NORETURN;
 extern void bb_show_usage(void) ATTRIBUTE_NORETURN ATTRIBUTE_EXTERNALLY_VISIBLE;
 extern void bb_error_msg(const char *s, ...) __attribute__ ((format (printf, 1, 2)));
 extern void bb_error_msg_and_die(const char *s, ...) __attribute__ ((noreturn, format (printf, 1, 2)));
@@ -670,8 +670,8 @@ const struct hwtype *get_hwntype(int type);
 
 
 #ifndef BUILD_INDIVIDUAL
-struct BB_applet;
-extern const struct BB_applet *find_applet_by_name(const char *name);
+struct bb_applet;
+extern const struct bb_applet *find_applet_by_name(const char *name);
 /* Returns only if applet is not found. */
 extern void run_applet_by_name(const char *name, int argc, char **argv);
 extern void run_current_applet_and_exit(int argc, char **argv) ATTRIBUTE_NORETURN;
@@ -880,7 +880,7 @@ enum {	/* DO NOT CHANGE THESE VALUES!  cp.c, mv.c, install.c depend on them. */
 };
 
 #define FILEUTILS_CP_OPTSTR "pdRfils" USE_SELINUX("c")
-extern const struct BB_applet *current_applet;
+extern const struct bb_applet *current_applet;
 extern const char *applet_name;
 extern const char BB_BANNER[];
 
diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index e0596d5f6..aa8fbb967 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -74,7 +74,7 @@ void complain_copyfd_and_die(off_t sz)
 	if (sz != -1)
 		bb_error_msg_and_die("short read");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	sleep_and_die();
+	xfunc_die();
 }
 #endif
 
@@ -94,7 +94,7 @@ void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
 	if (sz != -1)
 		bb_error_msg_and_die("short read");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	sleep_and_die();
+	xfunc_die();
 }
 
 off_t bb_copyfd_eof(int fd1, int fd2)
diff --git a/libbb/error_msg_and_die.c b/libbb/error_msg_and_die.c
index 39178a3ce..4a9049364 100644
--- a/libbb/error_msg_and_die.c
+++ b/libbb/error_msg_and_die.c
@@ -10,14 +10,25 @@
 #include "libbb.h"
 
 int die_sleep;
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
 jmp_buf die_jmp;
+#endif
 
-void sleep_and_die(void)
+void xfunc_die(void)
 {
 	if (die_sleep) {
-		/* Special case: don't die, but jump */
-		if (die_sleep < 0)
-			longjmp(die_jmp, xfunc_error_retval);
+		if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && die_sleep < 0) {
+			/* Special case. We arrive here if NOFORK applet
+			 * calls xfunc, which then decides to die.
+			 * We don't die, but jump instead back to caller.
+			 * NOFORK applets still cannot carelessly call xfuncs:
+			 * p = xmalloc(10);
+			 * q = xmalloc(10); // BUG! if this dies, we leak p!
+			 */
+			/* -111 means "zero" (longjmp can't pass 0)
+			 * spawn_and_wait() catches -111. */
+			longjmp(die_jmp, xfunc_error_retval ? xfunc_error_retval : -111);
+		}
 		sleep(die_sleep);
 	}
 	exit(xfunc_error_retval);
@@ -30,5 +41,5 @@ void bb_error_msg_and_die(const char *s, ...)
 	va_start(p, s);
 	bb_verror_msg(s, p, NULL);
 	va_end(p);
-	sleep_and_die();
+	xfunc_die();
 }
diff --git a/libbb/fflush_stdout_and_exit.c b/libbb/fflush_stdout_and_exit.c
index ae68222b4..d79827f45 100644
--- a/libbb/fflush_stdout_and_exit.c
+++ b/libbb/fflush_stdout_and_exit.c
@@ -13,13 +13,17 @@
 
 #include "libbb.h"
 
-// TODO: make it safe to call from NOFORK applets
-// Currently, it can exit(0). Even if it is made to do longjmp trick
-// (see sleep_and_die internals), zero cannot be passed thru this way!
-
 void fflush_stdout_and_exit(int retval)
 {
 	if (fflush(stdout))
-		sleep_and_die();
+		xfunc_die();
+
+	if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && die_sleep < 0) {
+		/* We are in NOFORK applet. Do not exit() directly,
+		 * but use xfunc_die() */
+		xfunc_error_retval = retval;
+		xfunc_die();
+	}
+
 	exit(retval);
 }
diff --git a/libbb/herror_msg_and_die.c b/libbb/herror_msg_and_die.c
index a7a22caf7..8c77378d7 100644
--- a/libbb/herror_msg_and_die.c
+++ b/libbb/herror_msg_and_die.c
@@ -7,9 +7,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdarg.h>
-#include <stdlib.h>
-
 #include "libbb.h"
 
 void bb_herror_msg_and_die(const char *s, ...)
@@ -19,5 +16,5 @@ void bb_herror_msg_and_die(const char *s, ...)
 	va_start(p, s);
 	bb_vherror_msg(s, p);
 	va_end(p);
-	sleep_and_die();
+	xfunc_die();
 }
diff --git a/libbb/perror_msg_and_die.c b/libbb/perror_msg_and_die.c
index 7521e7157..3a06b654b 100644
--- a/libbb/perror_msg_and_die.c
+++ b/libbb/perror_msg_and_die.c
@@ -7,10 +7,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
 #include "libbb.h"
 
 void bb_perror_msg_and_die(const char *s, ...)
@@ -20,5 +16,5 @@ void bb_perror_msg_and_die(const char *s, ...)
 	va_start(p, s);
 	bb_vperror_msg(s, p);
 	va_end(p);
-	sleep_and_die();
+	xfunc_die();
 }
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 286ee2678..dabd1a6d6 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -16,7 +16,7 @@
  */
 
 #include <paths.h>
-#include "busybox.h" /* for struct BB_applet */
+#include "busybox.h" /* for struct bb_applet */
 
 /* This does a fork/exec in one call, using vfork().  Returns PID of new child,
  * -1 for failure.  Runs argv[0], searching path if that has no / in it. */
@@ -104,8 +104,9 @@ int spawn_and_wait(char **argv)
 {
 	int rc;
 
-	if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
-		const struct BB_applet *a = find_applet_by_name(argv[0]);
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
+	{
+		const struct bb_applet *a = find_applet_by_name(argv[0]);
 		if (a && (a->nofork
 #ifndef BB_NOMMU
 			 || a->noexec /* NOEXEC cannot be used on NOMMU */
@@ -120,19 +121,27 @@ int spawn_and_wait(char **argv)
 #endif
 			{
 				int old_sleep = die_sleep;
+				int old_x = xfunc_error_retval;
 				die_sleep = -1; /* special flag */
-				/* sleep_and_die() checks for it */
+				/* xfunc_die() checks for it */
+
 				rc = setjmp(die_jmp);
 				if (!rc) {
-					const struct BB_applet *old_a = current_applet;
+					const struct bb_applet *old_a = current_applet;
 					current_applet = a;
 					applet_name = a->name;
 // what else should we save/restore?
 					rc = a->main(argc, argv);
 					current_applet = old_a;
 					applet_name = old_a->name;					
+				} else {
+					/* xfunc died in NOFORK applet */
+					if (rc == -111)
+						rc = 0;
 				}
+
 				die_sleep = old_sleep;
+				xfunc_error_retval = old_x;
 				return rc;
 			}
 #ifndef BB_NOMMU	/* MMU only */
@@ -145,9 +154,13 @@ int spawn_and_wait(char **argv)
 			run_current_applet_and_exit(argc, argv);
 #endif
 		}
+
 	}
 	rc = spawn(argv);
  w:
+#else /* !FEATURE_EXEC_PREFER_APPLETS */
+	rc = spawn(argv);
+#endif /* FEATURE_EXEC_PREFER_APPLETS */
 	return wait4pid(rc);
 }
 
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index 8466325c7..e7d510678 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -166,7 +166,7 @@ USE_FEATURE_IPV6(sa_family_t af,)
 	if (rc || !result) {
 		bb_error_msg("bad address '%s'", org_host);
 		if (ai_flags & DIE_ON_ERROR)
-			sleep_and_die();
+			xfunc_die();
 		goto ret;
 	}
 	r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index fa4a15236..b9d013a24 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -476,7 +476,7 @@ void xprint_and_close_file(FILE *file)
 	fflush(stdout);
 	// copyfd outputs error messages for us.
 	if (bb_copyfd_eof(fileno(file), 1) == -1)
-		sleep_and_die();
+		xfunc_die();
 
 	fclose(file);
 }
diff --git a/shell/ash.c b/shell/ash.c
index f98fc4178..b4278424a 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6533,7 +6533,7 @@ tryexec(char *cmd, char **argv, char **envp)
 
 #if ENABLE_FEATURE_SH_STANDALONE_SHELL
 	if (strchr(cmd, '/') == NULL) {
-		const struct BB_applet *a;
+		const struct bb_applet *a;
 
 		a = find_applet_by_name(cmd);
 		if (a) {
diff --git a/shell/msh.c b/shell/msh.c
index 3a5c85050..23a7c0498 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -3197,7 +3197,7 @@ static int dohelp(struct op *t)
 	}
 #if ENABLE_FEATURE_SH_STANDALONE_SHELL
 	{
-		const struct BB_applet *applet = applets;
+		const struct bb_applet *applet = applets;
 
 		while (applet->name) {
 			col += printf("%c%s", ((col == 0) ? '\t' : ' '), applet->name);
diff --git a/util-linux/getopt.c b/util-linux/getopt.c
index fefa02206..85a1d4410 100644
--- a/util-linux/getopt.c
+++ b/util-linux/getopt.c
@@ -51,10 +51,8 @@ enum {
 	OPT_s	= 0x10,	// -s
 	OPT_T	= 0x20,	// -T
 	OPT_u	= 0x40,	// -u
-#if ENABLE_GETOPT_LONG
 	OPT_a	= 0x80,	// -a
 	OPT_l	= 0x100, // -l
-#endif
 	SHELL_IS_TCSH = 0x8000, /* hijack this bit for other purposes */
 };