reviving libbusybox, adding CONFIG_INDIVIDUAL part 4

3 files changed, 109 insertions, 15 deletions

diff --git a/Config.in b/Config.in
index 64281f03e..b046812c7 100644
--- a/Config.in
+++ b/Config.in
@@ -311,24 +311,32 @@ config BUILD_LIBBUSYBOX
 ###
 ###       Say 'N' if in doubt.
 
+config FEATURE_INDIVIDUAL
+        bool "Produce a binary for each applet, linked against libbusybox"
+        default y
+        depends on !STATIC && BUILD_LIBBUSYBOX
+        help
+          If your CPU architecture doesn't allow for sharing text/rodata
+          sections of running binaries, but allows for runtime dynamic
+          libraries, this option will allow you to reduce memory footprint
+          when you have many different applets running at once.
+
+          If your CPU architecture allows for sharing text/rodata,
+          having single binary is more optimal.
+
+          Each applet will be a tiny program, dynamically linked
+          against libbusybox.so.N.N.N.
+
+          You need to have a working dynamic linker.
+
 config FEATURE_SHARED_BUSYBOX
         bool "Produce additional busybox binary linked against libbusybox"
-        default y if BUILD_LIBBUSYBOX
+        default y
         depends on !STATIC && BUILD_LIBBUSYBOX
         help
-          You need to have a working dynamic linker to use this variant.
+          Build busybox, dynamically linked against libbusybox.so.N.N.N.
 
-config LFS
-        bool "Build with Large File Support (for accessing files > 2 GB)"
-        default n
-        select FDISK_SUPPORT_LARGE_DISKS
-        help
-          If you want to build BusyBox with large file support, then enable
-          this option.  This will have no effect if your kernel or your C
-          library lacks large file support for large files.  Some of the
-          programs that can benefit from large file support include dd, gzip,
-          cp, mount, tar, and many others.  If you want to access files larger
-          than 2 Gigabytes, enable this option.  Otherwise, leave it set to 'N'.
+          You need to have a working dynamic linker.
 
 ### config BUILD_AT_ONCE
 ###     bool "Compile all sources at once"
@@ -349,6 +357,18 @@ config LFS
 ###
 ###       Say 'N' unless you know what you are doing.
 
+config LFS
+        bool "Build with Large File Support (for accessing files > 2 GB)"
+        default n
+        select FDISK_SUPPORT_LARGE_DISKS
+        help
+          If you want to build BusyBox with large file support, then enable
+          this option.  This will have no effect if your kernel or your C
+          library lacks large file support for large files.  Some of the
+          programs that can benefit from large file support include dd, gzip,
+          cp, mount, tar, and many others.  If you want to access files larger
+          than 2 Gigabytes, enable this option.  Otherwise, leave it set to 'N'.
+
 endmenu
 
 menu 'Debugging Options'
diff --git a/include/applets.h b/include/applets.h
index e88192d24..ac3f65f6d 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -30,6 +30,13 @@ s     - suid type:
 # 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(NAME_MAIN_CNAME)
+# define APPLET(name,l,s)                    name name##_main name
+# define APPLET_NOUSAGE(name,main,l,s)       name main##_main name
+# define APPLET_ODDNAME(name,main,l,s,name2) name main##_main name2
+# define APPLET_NOEXEC(name,main,l,s,name2)  name main##_main name2
+# define APPLET_NOFORK(name,main,l,s,name2)  name main##_main name2
+
 #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"
@@ -373,7 +380,7 @@ USE_YES(APPLET_NOFORK(yes, yes, _BB_DIR_USR_BIN, _BB_SUID_NEVER, yes))
 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)
+#if !defined(PROTOTYPES) && !defined(NAME_MAIN_CNAME) && !defined(MAKE_USAGE)
         { NULL }
 };
 #endif
diff --git a/scripts/trylink b/scripts/trylink
index de60a2cf7..a87d67225 100755
--- a/scripts/trylink
+++ b/scripts/trylink
@@ -137,7 +137,7 @@ if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
         -o $EXE -Wl,-Map -Wl,$EXE.map \
         -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
         -Wl,--start-group $O_FILES -Wl,--end-group \
-        $l_list -Wl,--verbose \
+        -Wl,--verbose \
         -L"$sharedlib_dir" -lbusybox \
         >/dev/null \
     || {
@@ -148,3 +148,70 @@ if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
     strip -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
     echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
 fi
+
+if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
+    gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
+    | grep -v "^#" \
+    | grep -v "^$" \
+    > applet.lst
+    while read name main cname; do
+
+        test x"$cname" = "x[" && cname=test
+        test x"$cname" = "x[[" && cname=test
+
+        echo "\
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include \"../include/autoconf.h\"
+#include \"../include/usage.h\"
+
+#ifdef __GLIBC__
+/* Make it reside in R/W memory: */
+int *const bb_errno __attribute__ ((section (\".data\")));
+#endif
+
+const char *applet_name = \"$name\";
+
+void bb_show_usage(void)
+{
+        fprintf(stderr, \"Usage: $name \"
+#ifdef ${cname}_trivial_usage
+                ${cname}_trivial_usage
+#endif
+#ifdef ${cname}_full_usage
+                \"\\n\\n\" ${cname}_full_usage
+#endif
+                \"\\n\\n\");
+        exit(1);
+}
+
+int $main(int argc, char **argv);
+
+int main(int argc, char **argv)
+{
+#ifdef __GLIBC__
+        (*(int **)&bb_errno) = __errno_location();
+#endif
+        return $main(argc, argv);
+}
+" >"$sharedlib_dir/applet.c"
+
+        EXE="$sharedlib_dir/$name"
+        try $CC $LDFLAGS "$sharedlib_dir/applet.c" \
+            -o $EXE \
+            -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
+            -L"$sharedlib_dir" -lbusybox \
+            >/dev/null \
+        || {
+            echo "Linking $EXE failed"
+            cat -- $EXE.out
+            exit 1
+        }
+        rm -- "$sharedlib_dir/applet.c" $EXE.out
+        strip -s --remove-section=.note --remove-section=.comment $EXE
+        echo "applet linked against libbusybox: $EXE"
+
+    done <applet.lst
+fi