Splitting these options makes it self-documenting about what
bash-compatible features we have.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Busybox uses FAST_FUNC macro to tweak with IA-32 calling conventions in
order to make the function call slightly smaller or slightly faster.
However, when I experiment with GCC's LTO (Link Time Optimization), I
discovered that FAST_FUNC could hinder LTO's optimization so that the
resulting executable become a few bytes larger (than what is compiled
without FAST_FUNC).
This change allows to specify e.g.
CONFIG_EXTRA_CFLAGS="-DFAST_FUNC= -flto"
and compile with LTO without a source code hack.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
* Fix a bug with a configuration in which the shell's kill builtin
would be mistreated as a killall command (i.e. '-q' works, and
'kill process_name' succeeds when it shouldn't):
CONFIG_ASH_JOB_CONTROL=y
CONFIG_HUSH_KILL=y
# CONFIG_KILL is not set
CONFIG_KILLALL=y
# CONFIG_KILLALL5 is not set
* Optimize out unneeded code when the relevant applets are not
selected.
* Move kbuild lines about shells' kill builtins from Kbuild.src to
kill.c, to accompany the new HAVE_SH_KILL macro. I hope this would
make maintanence a little bit easier.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
(I'm requesting for a review first because I fear such an aggressive
change could lead to bugs. While I observe the sizes have reduced, I
haven't test the functionality of each applet after that. So please
test before merging.)
Aggressively cut off unneeded code when the relevant applets are not
built.
Correct dependencies of FEATURE_MODPROBE_SMALL_OPTIONS_ON_CMDLINE and
FEATURE_MODPROBE_SMALL_CHECK_ALREADY_LOADED.
Don't bother with the '-r' option check if only rmmod is built (assume
true then), or when neither rmmod or mobprobe is built (assume false
then).
Size comparison before and after the change (single applet
configuration):
text data bss dec hex filename
34778 946 112 35836 8bfc old/busybox_DEPMOD
34151 946 112 35209 8989 new/busybox_DEPMOD
34903 946 112 35961 8c79 old/busybox_INSMOD
28316 778 112 29206 7216 new/busybox_INSMOD
35228 962 112 36302 8dce old/busybox_LSMOD
5011 706 40 5757 167d new/busybox_LSMOD
34830 946 112 35888 8c30 old/busybox_MODPROBE
34795 946 112 35853 8c0d new/busybox_MODPROBE
34718 946 112 35776 8bc0 old/busybox_RMMOD
7502 714 104 8320 2080 new/busybox_RMMOD
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
With the new "select PLATFORM_LINUX" mechanism
(commit e3b1a1fd28), the PLATFORM_LINUX
option alone no longer has any purpose of changing program behavior or
affecting compiled code. So there is no longer need to prompt user of
this config question.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This example single-applet configuration would trigger the bloat:
CONFIG_FEATURE_SEAMLESS_XZ=y
CONFIG_FEATURE_SEAMLESS_LZMA=y
CONFIG_FEATURE_SEAMLESS_BZ2=y
CONFIG_FEATURE_SEAMLESS_GZ=y
CONFIG_BUNZIP2=y
# CONFIG_ZCAT is not set
# All other applets disabled
Here, the resulting "busybox-bunzip2" binary would contain
unpack_gz_stream, unpack_lzma_stream and unpack_xz_stream functions
code. In other words, the gzip, lzma and xz decompressors' code are
linked into the binary unnecessarily.
This happens because SEAMLESS_MAGIC != 0 and compiler is unable
to figure out that SEAMLESS_MAGIC bit is never set.
Fix this by disabling SEAMLESS_MAGIC option flag (setting its value
to 0) when zcat is disabled. This will help the compiler optimize out
bbunpack() and no longer generate open_zipped() function call.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
ix ash "kill %1" not working if CONFIG_ASH is disabled but
ash is launched by 'sh' or 'bash' name
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This would makes all ash options indented inside "ash" in menuconfig.
It appears that menuconfig has a limit at tracking multiple dependency
lines like this (it looks like a "diamond problem" but I'm not sure if
it is):
---ASH <----------
/ \ ASH_OPTIMIZE_FOR_SIZE
!NOMMU <-*----SH_IS_ASH <----[OR] <--ASH_INTERNAL_GLOB
\ / ASH_RANDOM_SUPPORT
---BASH_IS_ASH <-- [...]
The kconfig-language document [1] states that:
> If a menu entry somehow depends on the previous entry, it can be
> made a submenu of it. First, the previous (parent) symbol must be
> part of the dependency list and then one of these two conditions
> must be true:
> - the child entry must become invisible, if the parent is set to 'n'
[BusyBox ash used to satisfy this, but no longer does]
> - the child entry must only be visible, if the parent is visible
[BusyBox ash configs actually satisfy this, but because of
"diamond" above this might not be easily detected]
So I found out a direct workaround: by making ash options explicitly
depend on !NOMMU, we can tell menuconfig that rule 2 above is satisfied
without any more tracking.
---------------------
/ \
!NOMMU <-*-----ASH <-------- \
\ \ \ ASH_OPTIMIZE_FOR_SIZE
*---SH_IS_ASH <---[OR]-[AND] <--ASH_INTERNAL_GLOB
\ / ASH_RANDOM_SUPPORT
--BASH_IS_ASH <- [...]
So all ash options would now be indented under "ash".
[1] "Documentation/kbuild/kconfig-language.txt" in Linux kernel source
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Mention the behavior if user selects CONFIG_SH_IS_ASH but not
CONFIG_ASH. We will be explicit that invocations like "busybox ash"
will not work for such configuration.
Also clarify help text of CONFIG_BASH_IS_* that bash compatibility in
ash is not complete. (It shouldn't be anyway - ash can't support every
bash quirk out there.)
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The filenames in docs/keep_data_small.txt are a little bit outdated.
It's better to change it to the current name.
decompress_unzip.c -> decompress_gunzip.c
(since commit 774bce8e8b)
libbb/messages.c -> libbb/ptr_to_globals.c
(since commit 574f2f4394)
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Kang-Che Sung