In Linux build system convention, pre-generated files are version-
controlled with a "_shipped" suffix. During the kernel building,
they are simply shipped (copied) removing the suffix.
This approach can reduce external tool dependency for the kernel build,
but it is tedious to manually regenerate such artifacts from developers'
point of view. (We need to do "make REGENERATE_PARSERS=1" every time
we touch real source files such as *.l, *.y)
Some months ago, I sent out RFC patches to run flex, bison, and gperf
during the build.
In the review and test, Linus noticed gperf-3.1 had changed the lookup
function prototype. Then, the use of gperf in kernel was entirely
removed by commit bb3290d916 ("Remove gperf usage from toolchain").
This time, I tested several versions of flex and bison, and I was not
hit by any compatibility issue except a flaw in flex-2.6.3; if you
generate lexer for dtc and genksyms with flex-2.6.3, you will see
"yywrap redefined" warning. This was not intentional, but a bug,
fixed by flex-2.6.4. Otherwise, both flex and bison look fairly
stable for a long time.
This commit prepares some build rules to remove the _shipped files.
Also, document minimal requirement for flex and bison.
Rationale for the minimal version:
The -Wmissing-prototypes option of GCC warns "no previous prototype"
for lexers generated by flex-2.5.34 or older, so I chose 2.5.35 as the
required version for flex. Flex-2.5.35 was released in 2008. Bison
looks more stable. I did not see any problem with bison-2.0, released
in 2004. I did not test bison-1.x, but bison-2.0 should be old enough.
Tested flex versions:
2.5.35
2.5.36
2.5.37
2.5.39
2.6.0
2.6.1
2.6.2
2.6.3 (*)
2.6.4
(*) flex-2.6.3 causes "yywrap redefined" warning
Tested bison versions:
2.0
2.1
2.2
2.3
2.4
2.4.1
2.5.1
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.6.5
2.7
2.7.1
3.0
3.0.1
3.0.2
3.0.3
3.0.4
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The toolchain used by Sphinx is somewhat complex, and installing
it should be part of the doc-guide.
Move it out of changes.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The kfigure module doesn't work with Sphinx version 1.2. So,
update the minimal requirements accordingly.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Thin archives migration by Nicholas Piggin.
THIN_ARCHIVES has been available for a while as an optional feature
only for PowerPC architecture, but we do not need two different
intermediate-artifact schemes.
Using thin archives instead of conventional incremental linking has
various advantages:
- save disk space for builds
- speed-up building a little
- fix some link issues (for example, allyesconfig on ARM) due to
more flexibility for the final linking
- work better with dead code elimination we are planning
As discussed before, this migration has been done unconditionally
so that any problems caused by this will show up with "git bisect".
With testing with 0-day and linux-next, some architectures actually
showed up problems, but they were trivial and all fixed now.
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Merge tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild thin archives updates from Masahiro Yamada:
"Thin archives migration by Nicholas Piggin.
THIN_ARCHIVES has been available for a while as an optional feature
only for PowerPC architecture, but we do not need two different
intermediate-artifact schemes.
Using thin archives instead of conventional incremental linking has
various advantages:
- save disk space for builds
- speed-up building a little
- fix some link issues (for example, allyesconfig on ARM) due to more
flexibility for the final linking
- work better with dead code elimination we are planning
As discussed before, this migration has been done unconditionally so
that any problems caused by this will show up with "git bisect".
With testing with 0-day and linux-next, some architectures actually
showed up problems, but they were trivial and all fixed now"
* tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
tile: remove unneeded extra-y in Makefile
kbuild: thin archives make default for all archs
x86/um: thin archives build fix
tile: thin archives fix linking
ia64: thin archives fix linking
sh: thin archives fix linking
kbuild: handle libs-y archives separately from built-in.o archives
kbuild: thin archives use P option to ar
kbuild: thin archives final link close --whole-archives option
ia64: remove unneeded extra-y in Makefile.gate
tile: fix dependency and .*.cmd inclusion for incremental build
sparc64: Use indirect calls in hamming weight stubs
Make thin archives build the default, but keep the config option
to allow exemptions if any breakage can't be quickly solved.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
DocBook is mentioned several times at the documentation. Update
the obsolete references from it at the DocBook.
Acked-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Commit 37d69ee308 ("docs: bump minimal GNU Make version to 3.81")
changes one entry of GNU make version in the changes.rst, there's still
one more entry saying that one need version 3.80. Fix that.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since 2014, you can't successfully build kernels with GNU Make version
3.80. Example errors:
$ git describe
v4.11
$ make --version | head -1
GNU Make 3.80
$ make defconfig
HOSTCC scripts/basic/fixdep
scripts/Makefile.host:135: *** missing separator. Stop.
make: *** [defconfig] Error 2
$ make ARCH=arm64 help
arch/arm64/Makefile:43: *** unterminated call to function `warning': missing `)'. Stop.
$ make help >/dev/null
./Documentation/Makefile.sphinx:25: Extraneous text after `else' directive
./Documentation/Makefile.sphinx:31: *** only one `else' per conditional. Stop.
make: *** [help] Error 2
The first breakage was introduced by commit c8589d1e9e ("kbuild:
handle multi-objs dependency appropriately"). Since then (i.e. v3.18),
GNU Make 3.80 has not been able to compile the kernel, but nobody has
ever complained aboutt (or noticed) it.
Even GNU Make 3.81 is more than 10 years old. It would not hurt to
match the documentation with reality instead of fixing makefiles.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As ftp.kernel.org is closed [0], this commit fixes dead URLs in
documents to use www.kernel.org instead.
[0] https://www.kernel.org/shutting-down-ftp-services.html
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Put like documents together, with the essential ones at the top, and split
the TOC into sections.
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add several documents to the development-process ReST book.
As we don't want renames, use symlinks instead, keeping those
documents on their original place.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Masahiro Yamada
Mauro Carvalho Chehab
Linus Torvalds
Nicholas Piggin
Max Filippov
SeongJae Park
Markus Heiser
Jonathan Corbet