busybox-w32/scripts/trylink, branch master

build system: actually detect lack of --warn-common

2024-01-21T15:27:38+00:00

Commit 992387539 (build system: more clang/llvm tweaks) falsely claimed that the lack of the --warn-common linker option was being detected. It wasn't, but it is now.

build system: more clang/llvm tweaks

2024-01-18T08:01:49+00:00

Linkers associated with clang/llvm may not support the -r option. This is used to create built-in.o object files. It turns out that all such files in busybox-w32 are either empty or only contain one object file. The first case is already supported and the second can be handled by simply copying the object file to built-in.o. The linker is therefore never invoked with the -r option. One adjustment is required: the workaround adopted for GitHub issue #200 linked the dummy C file with the resource object file. This is no longer done so only one object file is used. Since it was the linking that broke the resource file, copying it is an equally effective fix for the issue. Some old linkers don't support the --warn-common option. The lack of this option was being detected but it was still sometimes used.

trylink: do not drop libs from CONFIG_EXTRA_LDLIBS

2021-02-23T22:09:49+00:00

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

scripts/trylink: be more clever when deciding that "lib elimination" has finished:

2018-11-19T19:36:16+00:00

Before: Trying libraries: crypt m resolv Library crypt is not needed, excluding it Library m is needed, can't exclude it (yet) Library resolv is needed, can't exclude it (yet) Library m is needed, can't exclude it (yet) Library resolv is needed, can't exclude it (yet) Final link with: m resolv After: Trying libraries: crypt m resolv Library crypt is not needed, excluding it Library m is needed, can't exclude it (yet) Library resolv is needed, can't exclude it (yet) Final link with: m resolv Signed-off-by: Denys Vlasenko

build system: FEATURE_LIBBUSYBOX_STATIC - try to pull libc/libm into libbusybox

2017-07-15T12:52:26+00:00

It variously fails with different toolchains I tried... Signed-off-by: Denys Vlasenko

remove "local" bashism from a few scripts

2017-01-24T19:52:42+00:00

Signed-off-by: Denys Vlasenko

trylink: use "mktemp tmp.XXXXXXXXXX" to placate OS X

2016-07-12T11:54:35+00:00

Signed-off-by: Denys Vlasenko

scripts/trylink: libbusybox fix

2016-06-20T10:23:35+00:00

gcc 6.1.1 can emit empty line with spaces Signed-off-by: Denys Vlasenko

scripts/trylink: document DATA_SEGMENT_ALIGN() hack

2016-04-22T00:00:04+00:00

Signed-off-by: Denys Vlasenko