Implement first instance of NOFORK applet - echo

find: use NOFORK/NOEXEC; small -exec buglet also eliminated
vfork_daemon_rexec: honor PREFER_APPLETS
echo: small size improvements

find -exec echo {} \; with PREFER_APPLETS=y runs 4 times faster



git-svn-id: svn://busybox.net/trunk/busybox@18372 69ca8d6d-28ef-0310-b511-8ec308f3f277

6 files changed, 77 insertions, 50 deletions

diff --git a/Config.in b/Config.in
index fea408148..59d7d6731 100644
--- a/Config.in
+++ b/Config.in
@@ -244,7 +244,8 @@ config FEATURE_EXEC_PREFER_APPLETS
         help
           This is an experimental option which directs applets about to
           call 'exec' to try and find an applicable busybox applet before
-          searching the executable path for a binary or symlink to execute.
+          searching the PATH. This may affect shell, find -exec, xargs and
+          similar programs.
 
 config BUSYBOX_EXEC_PATH
         string "Path to BusyBox executable"
diff --git a/coreutils/echo.c b/coreutils/echo.c
index 8270fc006..486245508 100644
--- a/coreutils/echo.c
+++ b/coreutils/echo.c
@@ -20,86 +20,85 @@
  * 1) In handling '\c' escape, the previous version only suppressed the
  *     trailing newline.  SUSv3 specifies _no_ output after '\c'.
  * 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
- *    The previous version version did not allow 4-digit octals.
+ *    The previous version did not allow 4-digit octals.
  */
 
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
 #include "busybox.h"
 
 int bb_echo(char **argv)
 {
-#ifndef CONFIG_FEATURE_FANCY_ECHO
+        const char *arg;
+#if !ENABLE_FEATURE_FANCY_ECHO
 #define eflag '\\'
         ++argv;
 #else
         const char *p;
-        int nflag = 1;
-        int eflag = 0;
+        char nflag = 1;
+        char eflag = 0;
+
+        while (1) {
+                arg = *++argv;
+                if (!arg)
+                        goto ret;
+                if (*arg != '-')
+                        break;
 
-        while (*++argv && (**argv == '-')) {
                 /* If it appears that we are handling options, then make sure
                  * that all of the options specified are actually valid.
                  * Otherwise, the string should just be echoed.
                  */
-
-                if (!*(p = *argv + 1)) {        /* A single '-', so echo it. */
+                p = arg + 1;
+                if (!*p)        /* A single '-', so echo it. */
                         goto just_echo;
-                }
 
                 do {
-                        if (strrchr("neE", *p) == 0) {
+                        if (!strrchr("neE", *p))
                                 goto just_echo;
-                        }
                 } while (*++p);
 
                 /* All of the options in this arg are valid, so handle them. */
-                p = *argv + 1;
+                p = arg + 1;
                 do {
-                        if (*p == 'n') {
+                        if (*p == 'n')
                                 nflag = 0;
-                        } else if (*p == 'e') {
+                        if (*p == 'e')
                                 eflag = '\\';
-                        } else {
-                                eflag = 0;
-                        }
                 } while (*++p);
         }
-
-just_echo:
+ just_echo:
 #endif
-        while (*argv) {
+        while (1) {
+                /* arg is already = *argv and isn't NULL */
                 int c;
 
-                while ((c = *(*argv)++)) {
+                while ((c = *arg++)) {
                         if (c == eflag) {       /* Check for escape seq. */
-                                if (**argv == 'c') {
+                                if (*arg == 'c') {
                                         /* '\c' means cancel newline and
                                          * ignore all subsequent chars. */
-                                        return 0;
+                                        goto ret;
                                 }
-#ifndef CONFIG_FEATURE_FANCY_ECHO
+#if !ENABLE_FEATURE_FANCY_ECHO
                                 /* SUSv3 specifies that octal escapes must begin with '0'. */
-                                if (((unsigned int)(**argv - '1')) >= 7)
+                                if ( (((unsigned char)*arg) - '1') >= 7)
 #endif
                                 {
                                         /* Since SUSv3 mandates a first digit of 0, 4-digit octals
                                         * of the form \0### are accepted. */
-                                        if ((**argv == '0') && (((unsigned int)(argv[0][1] - '0')) < 8)) {
-                                                (*argv)++;
+                                        if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
+                                                arg++;
                                         }
                                         /* bb_process_escape_sequence can handle nul correctly */
-                                        c = bb_process_escape_sequence((const char **) argv);
+                                        c = bb_process_escape_sequence(&arg);
                                 }
                         }
                         putchar(c);
                 }
 
-                if (*++argv) {
-                        putchar(' ');
-                }
+                arg = *++argv;
+                if (!arg)
+                        break;
+                putchar(' ');
         }
 
 #ifdef CONFIG_FEATURE_FANCY_ECHO
@@ -109,14 +108,16 @@ just_echo:
 #else
         putchar('\n');
 #endif
-        return 0;
+ ret:
+        return fflush(stdout);
 }
 
+/* This is a NOFORK applet. Be very careful! */
+
 int echo_main(int argc, char** argv);
 int echo_main(int argc, char** argv)
 {
-        (void)bb_echo(argv);
-        fflush_stdout_and_exit(EXIT_SUCCESS);
+        return bb_echo(argv);
 }
 
 /*-
diff --git a/findutils/find.c b/findutils/find.c
index 594eafca4..7b5a09d56 100644
--- a/findutils/find.c
+++ b/findutils/find.c
@@ -242,9 +242,30 @@ ACTF(exec)
         for (i = 0; i < ap->exec_argc; i++)
                 argv[i] = subst(ap->exec_argv[i], ap->subst_count[i], fileName);
         argv[i] = NULL; /* terminate the list */
-        rc = wait4pid(spawn(argv));
-        if (rc)
+
+        if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
+                const struct BB_applet *a = find_applet_by_name(argv[0]);
+                if (a) {
+                        if (a->nofork) {
+                                rc = a->main(ap->exec_argc, argv);
+                                goto f;
+                        }
+#ifndef BB_NOMMU
+                        if (a->noexec) {
+                                rc = fork();
+                                if (rc) goto w;
+                                current_applet = a;
+                                run_current_applet_and_exit(ap->exec_argc, argv);
+                        }
+#endif
+                }
+        }
+        rc = spawn(argv);
+ w:
+        rc = wait4pid(rc);
+        if (rc < 0)
                 bb_perror_msg("%s", argv[0]);
+ f:
         for (i = 0; i < ap->exec_argc; i++)
                 free(argv[i]);
         return rc == 0; /* return 1 if success */
diff --git a/include/applets.h b/include/applets.h
index f411aa258..f20b79629 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -28,24 +28,28 @@ s     - suid type:
 # define APPLET_NOUSAGE(name,main,l,s)       int main##_main(int argc, char **argv);
 # define APPLET_ODDNAME(name,main,l,s,name2) int main##_main(int argc, char **argv);
 # define APPLET_NOEXEC(name,main,l,s,name2)  int main##_main(int argc, char **argv);
+# define APPLET_NOFORK(name,main,l,s,name2)  int main##_main(int argc, char **argv);
 
 #elif defined(MAKE_USAGE) && ENABLE_FEATURE_VERBOSE_USAGE
 # define APPLET(name,l,s)                    name##_trivial_usage "\n\n" name##_full_usage "\0"
 # define APPLET_NOUSAGE(name,main,l,s)       "\b\0"
 # define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
 # define APPLET_NOEXEC(name,main,l,s,name2)  name2##_trivial_usage "\n\n" name2##_full_usage "\0"
+# define APPLET_NOFORK(name,main,l,s,name2)  name2##_trivial_usage "\n\n" name2##_full_usage "\0"
 
 #elif defined(MAKE_USAGE) && !ENABLE_FEATURE_VERBOSE_USAGE
 # define APPLET(name,l,s)                    name##_trivial_usage "\0"
 # define APPLET_NOUSAGE(name,main,l,s)       "\b\0"
 # define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\0"
 # define APPLET_NOEXEC(name,main,l,s,name2)  name2##_trivial_usage "\0"
+# define APPLET_NOFORK(name,main,l,s,name2)  name2##_trivial_usage "\0"
 
 #elif defined(MAKE_LINKS)
 # define APPLET(name,l,c)                    LINK l name
 # define APPLET_NOUSAGE(name,main,l,s)       LINK l name
 # define APPLET_ODDNAME(name,main,l,s,name2) LINK l name
 # define APPLET_NOEXEC(name,main,l,s,name2)  LINK l name
+# define APPLET_NOFORK(name,main,l,s,name2)  LINK l name
 
 #else
   const struct BB_applet applets[] = { /*    name,main,location,need_suid */
@@ -53,6 +57,7 @@ s     - suid type:
 # 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},
 #endif
 
 #if ENABLE_INSTALL_NO_USR
@@ -118,7 +123,7 @@ USE_DUMPKMAP(APPLET(dumpkmap, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_APP_DUMPLEASES(APPLET(dumpleases, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 //USE_E2FSCK(APPLET(e2fsck, _BB_DIR_SBIN, _BB_SUID_NEVER))
 //USE_E2LABEL(APPLET_NOUSAGE(e2label, tune2fs, _BB_DIR_SBIN, _BB_SUID_NEVER))
-USE_ECHO(APPLET_NOEXEC(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
+USE_ECHO(APPLET_NOFORK(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
 USE_ED(APPLET(ed, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_FEATURE_GREP_EGREP_ALIAS(APPLET_NOUSAGE(egrep, grep, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_EJECT(APPLET(eject, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
diff --git a/libbb/process_escape_sequence.c b/libbb/process_escape_sequence.c
index 138e751f5..3178ad34a 100644
--- a/libbb/process_escape_sequence.c
+++ b/libbb/process_escape_sequence.c
@@ -8,9 +8,6 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <limits.h>
-#include <ctype.h>
 #include "libbb.h"
 
 #define WANT_HEX_ESCAPES 1
@@ -46,10 +43,10 @@ char bb_process_escape_sequence(const char **ptr)
 #endif
 
         do {
-                d = (unsigned int)(*q - '0');
+                d = (unsigned char)(*q) - '0';
 #ifdef WANT_HEX_ESCAPES
                 if (d >= 10) {
-                        d = ((unsigned int)(_tolower(*q) - 'a')) + 10;
+                        d = (unsigned char)(_tolower(*q)) - 'a' + 10;
                 }
 #endif
 
@@ -80,7 +77,7 @@ char bb_process_escape_sequence(const char **ptr)
                                 break;
                         }
                 } while (*++p);
-                n = *(p+(sizeof(charmap)/2));
+                n = *(p + (sizeof(charmap)/2));
         }
 
         *ptr = q;
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index ec8b9b1d7..11dbb24fc 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -26,14 +26,16 @@ pid_t spawn(char **argv)
         volatile int failed;
         pid_t pid;
 
-        // Be nice to nommu machines.
+// Ain't it a good place to fflush(NULL)?
+
+        /* Be nice to nommu machines. */
         failed = 0;
         pid = vfork();
         if (pid < 0) /* error */
                 return pid;
         if (!pid) { /* child */
-                /* Don't use BB_EXECVP tricks here! */
-                execvp(argv[0], argv);
+                /* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */
+                BB_EXECVP(argv[0], argv);
 
                 /* We are (maybe) sharing a stack with blocked parent,
                  * let parent know we failed and then exit to unblock parent