busybox/archival
James Byrne 6937487be7 libbb: reduce the overhead of single parameter bb_error_msg() calls
Back in 2007, commit 0c97c9d437 ("'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 <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 11:35:03 +02:00
..
libarchive libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
ar.c regularize format of source file headers, no code changes 2017-09-18 16:28:43 +02:00
bbunzip_test2.sh add tests for gunzip 2007-10-05 15:27:03 +00:00
bbunzip_test3.sh add tests for gunzip 2007-10-05 15:27:03 +00:00
bbunzip_test.sh add tests for gunzip 2007-10-05 15:27:03 +00:00
bbunzip.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
bzip2.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
Config.src restore documentation on the build config language 2018-06-06 15:16:48 +02:00
cpio.c config: update size information 2018-12-28 03:20:17 +01:00
dpkg_deb.c config: dpkg_deb should be dpkg-deb 2018-12-28 18:24:45 +01:00
dpkg.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
gzip.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
Kbuild.src cpio: implement -R/--owner 2015-10-16 17:24:46 +02:00
lzop.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
rpm.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
rpm.h *: make GNU licensing statement forms more regular 2010-08-16 20:14:46 +02:00
tar_symlink_attack tar: postpone creation of symlinks with "suspicious" targets. Closes 8411 2017-07-24 17:20:13 +02:00
tar.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00
unzip.c libbb: reduce the overhead of single parameter bb_error_msg() calls 2019-07-02 11:35:03 +02:00