add more convenient defines for [NO]MMU:

"#ifndef BB_NOMMU" is a double negative

6 files changed, 30 insertions, 27 deletions

diff --git a/applets/applets.c b/applets/applets.c
index 56e0d2ccc..6f38ccee8 100644
--- a/applets/applets.c
+++ b/applets/applets.c
@@ -51,7 +51,7 @@ const unsigned short NUM_APPLETS = sizeof(applets) / sizeof(applets[0]) - 1;
 
 const struct bb_applet *current_applet;
 const char *applet_name ATTRIBUTE_EXTERNALLY_VISIBLE;
-#ifdef BB_NOMMU
+#if !BB_MMU
 bool re_execed;
 #endif
 
@@ -612,7 +612,7 @@ int main(int argc, char **argv)
 {
         const char *s;
 
-#ifdef BB_NOMMU
+#if !BB_MMU
         /* NOMMU re-exec trick sets high-order bit in first byte of name */
         if (argv[0][0] & 0x80) {
                 re_execed = 1;
diff --git a/include/libbb.h b/include/libbb.h
index 04bf6a5cd..11fcd19f2 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -269,6 +269,8 @@ char *xrealloc_getcwd_or_warn(char *cwd);
 char *xmalloc_readlink_or_warn(const char *path);
 char *xmalloc_realpath(const char *path);
 
+
+//TODO: signal(sid, f) is the same? then why?
 extern void sig_catch(int,void (*)(int));
 //#define sig_ignore(s) (sig_catch((s), SIG_IGN))
 //#define sig_uncatch(s) (sig_catch((s), SIG_DFL))
@@ -278,7 +280,6 @@ extern void sig_unblock(int);
 extern void sig_pause(void);
 
 
-
 void xsetgid(gid_t gid);
 void xsetuid(uid_t uid);
 void xchdir(const char *path);
@@ -519,15 +520,14 @@ pid_t xspawn(char **argv);
 
 /* Unlike waitpid, waits ONLY for one process,
  * It's safe to pass negative 'pids' from failed [v]fork -
- * wait4pid will return -1 and ECHILD in errno.
+ * wait4pid will return -1 (and will not clobber [v]fork's errno).
  * IOW: rc = wait4pid(spawn(argv));
  *      if (rc < 0) bb_perror_msg("%s", argv[0]);
  *      if (rc > 0) bb_error_msg("exit code: %d", rc);
  */
+int wait4pid(int pid);
 int wait_pid(int *wstat, int pid);
 int wait_nohang(int *wstat);
-int wait4pid(int pid);
-//TODO: signal(sid, f) is the same? then why?
 #define wait_crashed(w) ((w) & 127)
 #define wait_exitcode(w) ((w) >> 8)
 #define wait_stopsig(w) ((w) >> 8)
@@ -564,7 +564,7 @@ enum {
         DAEMON_CLOSE_EXTRA_FDS = 4,
         DAEMON_ONLY_SANITIZE = 8, /* internal use */
 };
-#ifndef BB_NOMMU
+#if BB_MMU
   void forkexit_or_rexec(void);
 # define forkexit_or_rexec(argv)            forkexit_or_rexec()
 # define bb_daemonize_or_rexec(flags, argv) bb_daemonize_or_rexec(flags)
diff --git a/include/platform.h b/include/platform.h
index 51add6c0f..d7389f1aa 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -212,7 +212,15 @@ typedef unsigned smalluint;
  */
 #if defined __UCLIBC__ && __UCLIBC_MAJOR__ >= 0 && __UCLIBC_MINOR__ >= 9 && \
     __UCLIBC_SUBLEVEL__ > 28 && !defined __ARCH_USE_MMU__
-#define BB_NOMMU
+#define BB_MMU 0
+#define BB_NOMMU 1
+#define USE_FOR_NOMMU(...) __VA_ARGS__
+#define USE_FOR_MMU(...)
+#else
+#define BB_MMU 1
+/* BB_NOMMU is not defined in this case! */
+#define USE_FOR_NOMMU(...)
+#define USE_FOR_MMU(...) __VA_ARGS__
 #endif
 
 /* Platforms that haven't got dprintf need to implement fdprintf() in
@@ -232,7 +240,7 @@ static ATTRIBUTE_ALWAYS_INLINE char* strchrnul(const char *s, char c) {
 }
 #endif
 
-/* Don't use lchown with glibc older than 2.1.x ... uC-libc lacks it */
+/* Don't use lchown with glibc older than 2.1.x ... uClibc lacks it */
 #if (defined __GLIBC__ && __GLIBC__ <= 2 && __GLIBC_MINOR__ < 1) || \
     defined __UC_LIBC__
 # define lchown chown
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 64952225d..281ead4dc 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -107,15 +107,15 @@ int spawn_and_wait(char **argv)
         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 */
+#if BB_MMU
+                 || a->noexec /* NOEXEC trick needs fork() */
 #endif
         )) {
                 int argc = 1;
                 char **pp = argv;
                 while (*++pp)
                         argc++;
-#ifndef BB_NOMMU
+#if BB_MMU
                 if (a->nofork)
 #endif
                 {
@@ -136,7 +136,7 @@ int spawn_and_wait(char **argv)
                                 applet_name = a->name;
 // what else should we save/restore?
 // TODO: what if applet will mangle argv vector?
-// xargs needs argv untouched because it frees the vector!
+// xargs needs argv untouched because it frees argv[i]!
 // shouldn't we pass a copy?
                                 rc = a->main(argc, argv);
                                 current_applet = old_a;
@@ -152,29 +152,25 @@ int spawn_and_wait(char **argv)
                         option_mask32 = old_m;
                         return rc;
                 }
-#ifndef BB_NOMMU        /* MMU only */
+#if BB_MMU
+                /* MMU only */
                 /* a->noexec is true */
                 rc = fork();
-                if (rc)
-                        goto w;
+                if (rc) /* parent or error */
+                        return wait4pid(rc);
                 /* child */
                 xfunc_error_retval = EXIT_FAILURE;
                 current_applet = a;
                 run_current_applet_and_exit(argc, argv);
 #endif
         }
+#endif /* FEATURE_PREFER_APPLETS */
         rc = spawn(argv);
-#ifndef BB_NOMMU
- w:
-#endif
         return wait4pid(rc);
-#else /* !FEATURE_PREFER_APPLETS */
-        return wait4pid(spawn(argv));
-#endif
 }
 
 
-#ifdef BB_NOMMU
+#if !BB_MMU
 void forkexit_or_rexec(char **argv)
 {
         pid_t pid;
@@ -210,7 +206,6 @@ void forkexit_or_rexec(void)
 #define forkexit_or_rexec(argv) forkexit_or_rexec()
 #endif
 
-
 /* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
  * char **argv "vanishes" */
 void bb_daemonize_or_rexec(int flags, char **argv)
diff --git a/networking/httpd.c b/networking/httpd.c
index 7ee62c32a..d80df937a 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -986,7 +986,7 @@ static int sendCgi(const char *url,
  *    since httpd is run from inetd (and it can't run standalone
  *    in uClinux).
  */
-#ifdef BB_NOMMU
+#if !BB_MMU
         pid = vfork();
 #else
         pid = fork();
diff --git a/networking/zcip.c b/networking/zcip.c
index 552833f9f..eb3c869ab 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -220,7 +220,7 @@ int zcip_main(int argc, char **argv)
                 }
         }
         // On NOMMU reexec early (or else we will rerun things twice)
-#ifdef BB_NOMMU
+#if !BB_MMU
         if (!FOREGROUND)
                 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
 #endif
@@ -268,7 +268,7 @@ int zcip_main(int argc, char **argv)
 
         // daemonize now; don't delay system startup
         if (!FOREGROUND) {
-#ifndef BB_NOMMU
+#if BB_MMU
                 bb_daemonize(DAEMON_CHDIR_ROOT);
 #endif
                 bb_info_msg("start, interface %s", intf);