busybox.git/libbb/appletlib.c, branch 1_32_stable

nologin: make it possible to build it as single applet

2020-06-24T13:05:22+00:00

Signed-off-by: Denys Vlasenko

clang/llvm 9 fix - do not eliminate a store to a fake "const"

2019-10-25T10:12:22+00:00

This is *much* better (9 kbytes better) than dropping "*const"
optimization trick.

Signed-off-by: Denys Vlasenko

libbb: reduce the overhead of single parameter bb_error_msg() calls

2019-07-02T09:35:03+00:00

Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().

This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.

Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.

This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.

The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):

Arm:     -92 bytes
MIPS:    -52 bytes
PPC:   -1836 bytes
x86_64: -938 bytes

Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.

Signed-off-by: James Byrne 
Signed-off-by: Denys Vlasenko

libbb: mark scripted_main() as externally visible

2019-03-30T15:46:27+00:00

Building with individual binaries enabled fails when embedded
script applets are included:

   /tmp/ccIvMFZg.o: In function `main':
   applet.c:(.text.main+0x20): undefined reference to `scripted_main'

Mark scripted_main() as externally visible.

Reported-by: Yann E. MORIN 
Signed-off-by: Ron Yorston 
Signed-off-by: Denys Vlasenko

single-applet build --help had extra \n, remove

2019-01-01T15:54:30+00:00

Signed-off-by: Denys Vlasenko

hush: allow hush to run embedded scripts

2018-11-27T15:13:07+00:00

Embedded scripts require a shell to be present in the BusyBox
binary.  Allow either ash or hush to be used for this purpose.
If both are enabled ash takes precedence.

The size of the binary is unchanged in the default configuration:
both ash and hush are present but support for embedded scripts
isn't compiled into hush.

Signed-off-by: Ron Yorston 
Signed-off-by: Denys Vlasenko

busybox: add '--show SCRIPT' option to display scripts

2018-11-18T18:19:29+00:00

Add an option to allow the content of embedded scripts to be
displayed.  This includes applet scripts, custom scripts and the
.profile script.

function                                             old     new   delta
busybox_main                                         624     701     +77
find_script_by_name                                    -      24     +24
scripted_main                                         41      35      -6
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/1 up/down: 101/-6)             Total: 95 bytes

Signed-off-by: Ron Yorston 
Signed-off-by: Denys Vlasenko

Treat custom and applet scripts as applets

2018-11-17T20:16:33+00:00

BusyBox has support for embedded shell scripts.  Two types can be
distinguished:  custom scripts and scripts implementing applets.

Custom scripts should be placed in the 'embed' directory at build
time.  They are given a default applet configuration and appear
as applets to the user but no further configuration is possible.

Applet scripts are integrated with the BusyBox build system and
are intended to be used to ship standard applets that just happen
to be implemented as scripts.  They can be configured at build time
and appear just like native applets.

Such scripts should be placed in the 'applets_sh' directory.  A stub
C program should be written to provide the usual applet configuration
details and placed in a suitable subsystem directory.  It may be
helpful to have a configuration option to enable any dependencies the
script requires:  see the 'nologin' applet for an example.

function                                             old     new   delta
scripted_main                                          -      41     +41
applet_names                                        2773    2781      +8
applet_main                                         1600    1604      +4
i2cdetect_main                                       672     674      +2
applet_suid                                          100     101      +1
applet_install_loc                                   200     201      +1
applet_flags                                         100     101      +1
packed_usage                                       33180   33179      -1
tryexec                                              159     152      -7
evalcommand                                         1661    1653      -8
script_names                                           9       -      -9
packed_scripts                                       123     114      -9
complete_cmd_dir_file                                826     811     -15
shellexec                                            271     254     -17
find_command                                        1007     990     -17
busybox_main                                         642     624     -18
run_applet_and_exit                                  100      78     -22
find_script_by_name                                   51       -     -51
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174)          Total: -116 bytes
   text	   data	    bss	    dec	    hex	filename
 950034	    477	   7296	 957807	  e9d6f	busybox_old
 949918	    477	   7296	 957691	  e9cfb	busybox_unstripped

Signed-off-by: Ron Yorston 
Signed-off-by: Denys Vlasenko

libarchive: add a function to unpack embedded data

2018-11-02T13:14:51+00:00

Similar code to unpack embedded data is used to decompress usage
messages, embedded scripts and the config file (in the non-default
bbconfig applet).

Moving this code to a common function reduces the size of the default
build and hides more of the internals of libarchive.

function                                             old     new   delta
unpack_bz2_data                                        -     135    +135
bb_show_usage                                        137     157     +20
get_script_content                                    32      47     +15
unpack_scripts                                       119       -    -119
unpack_usage_messages                                124       -    -124
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 2/0 up/down: 170/-243)          Total: -73 bytes

Signed-off-by: Ron Yorston 
Signed-off-by: Denys Vlasenko

busybox: show embedded scripts in applet list

2018-11-01T12:58:16+00:00

function                                             old     new   delta
busybox_main                                         624     642     +18

Signed-off-by: Denys Vlasenko