busybox.git/Makefile.flags, branch 1_32_stable

Makefile.flags: restrict Wno-constant-logical-operand and Wno-string-plus-int options for clang

2020-06-10T12:33:19+00:00

these options were added in b4ef2e3467d8e980ccf13c9dd342459c013b455f commit
gcc shows unrecognized command-line option warnings

Signed-off-by: Biswapriyo Nath 
Signed-off-by: Denys Vlasenko

build system: remove KBUILD_STR()

2020-04-29T12:52:19+00:00

When using GNU Make >=4.3, the KBUILD_STR() definition interferes badly
with dependency checks during build, and forces a complete rebuild every
time Make runs.

In if_changed_rule, Kconfig checks if the command used to build a file
has changed since last execution. The previous command is stored in the
generated ..o.cmd file. For example applets/.applets.o.cmd defines
a "cmd_applets/applets.o" variable:

	cmd_applets/applets.o := gcc ... -D"KBUILD_STR(s)=#s" ...

Here the '#' should be escaped with a backslash, otherwise GNU Make
interprets it as starting a comment, and ignore the rest of the
variable. As a result of this truncation, the previous command doesn't
equal the new command and Make rebuilds each target.

The problem started to appear when GNU Make 4.3 (released January 2020),
introduced a backward-incompatible fix to macros containing a '#'. While
the above use of '#', a simple Make variable, still needs to be escaped,
a '#' within a function invocation doesn't need to be escaped anymore.
As Martin Dorey explained on the GNU Make discussion [1], the above
declaration is generated from make-cmd, defined as:

	make-cmd = $(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))

Since GNU Make 4.3, the first argument of subst should not have a
backslash. make-cmd now looks for literally \# and doesn't find it, and
as a result doesn't add the backslash when generating .o.cmd files.

[1] http://savannah.gnu.org/bugs/?20513

We could fix it by changing make-cmd to "$(subst #,\#,...)", but to
avoid compatibility headaches, simply get rid of the KBUILD_STR
definition, as done in Linux by b42841b7bb62 ("kbuild: Get rid of
KBUILD_STR"). Quote the string arguments directly rather than asking the
preprocessor to quote them.

Signed-off-by: Jean-Philippe Brucker 
Signed-off-by: Denys Vlasenko

Makefile.flags: suppress some clang-9 warnings

2019-10-25T10:56:51+00:00

Signed-off-by: Denys Vlasenko

Remove syscall wrappers around clock_gettime, closes 12091

2019-10-24T14:26:55+00:00

12091 "Direct use of __NR_clock_gettime is not time64-safe".

function                                             old     new   delta
runsv_main                                          1698    1712     +14
startservice                                         378     383      +5
get_mono                                              31      25      -6
date_main                                            932     926      -6
gettimeofday_ns                                       17       -     -17
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/2 up/down: 19/-29)            Total: -10 bytes

Signed-off-by: Denys Vlasenko

build system: FEATURE_NSLOOKUP_BIG needs -lresolv

2018-04-16T09:04:03+00:00

Signed-off-by: Denys Vlasenko

Change BB_EXTRA_VERSION: now it needs to contain any spaces/parenthesis

2017-07-04T14:01:12+00:00

Before this change, BB_EXTRA_VERSION of "" resulted in:

	"BusyBox v1.28.0.git () multi-call binary"

message, after the fix it is:

	"BusyBox v1.28.0.git multi-call binary"

While at it, eliminate BB_BT and BANNER single-use macros.

Signed-off-by: Denys Vlasenko

build: add a sanitizer debug option

2016-02-13T03:12:47+00:00

Building & running with ASAN is super helpful, so add a dedicated config
knob for it.  This way people don't have to guess at the right compiler
settings in order to get a good build.  We can just tell people to enable
this one option.

Signed-off-by: Mike Frysinger

build system: remove special-casing for extra libs

2015-10-12T01:12:17+00:00

It is not reliable (tried on three systems, multiple problems).

Signed-off-by: Denys Vlasenko

build system: -fno-builtin-printf

2015-10-07T20:42:45+00:00

Benefits are: drops reference to out-of-line putchar(), fixes a few cases
of failed string merge.

function                                             old     new   delta
i2cdump_main                                        1488    1502     +14
sha256_process_block64                               423     433     +10
sendmail_main                                       1183    1185      +2
list_table                                          1114    1116      +2
i2cdetect_main                                      1235    1237      +2
fdisk_main                                          2852    2854      +2
builtin_type                                         119     121      +2
unicode_conv_to_printable2                           325     324      -1
scan_recursive                                       380     378      -2
mkfs_minix_main                                     2687    2684      -3
buffer_fill_and_print                                178     169      -9
putchar                                              152       -    -152
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 7/4 up/down: 34/-167)          Total: -133 bytes
   text    data     bss     dec     hex filename
 937788     932   17676  956396   e97ec busybox_old
 937564     932   17676  956172   e970c busybox_unstripped

Signed-off-by: Denys Vlasenko

Aboriginal linux/musl build fixes

2015-10-05T09:15:43+00:00

Signed-off-by: Denys Vlasenko