In Linux build system convention, we do not run tools such as
flex, bison, gperf during the kernel building. Instead, manage
generated C files in the repository with _shipped suffixes.
They are simply shipped (copied) removing the _shipped suffixes
during the kernel building.
Commit 7373f4f83c71 ("kbuild: add implicit rules for parser generation")
added a mechanism to regenerate intermediate C files easily.
The build rules are surrounded with ifdef REGENERATE_PARSERS.
So, we need to pass REGENERATE_PARSERS=1 from the command line
when we want to update them.
Here is one question. Is it acceptable to use those rules all the time?
That is, generate those C files by flex, bison, gperf during the
kernel building.
This means, the build system depends on more external tools.
>From the users' point of view, they will need to install
flex, bison, gperf in order to build the kernel.
>From the developers' point of view, the advantage is
we do not need to version-control generated files, i.e. _shipped files
will be deleted.
I'd like to know if this is acceptable or not.
For example, currently some files are simply shipped (copied)
when building the kconfig program.
$ make mrproper; make defconfig
HOSTCC scripts/basic/fixdep
HOSTCC scripts/kconfig/conf.o
SHIPPED scripts/kconfig/zconf.tab.c
SHIPPED scripts/kconfig/zconf.lex.c
SHIPPED scripts/kconfig/zconf.hash.c
HOSTCC scripts/kconfig/zconf.tab.o
HOSTLD scripts/kconfig/conf
*** Default configuration is based on 'x86_64_defconfig'
#
# configuration written to .config
#
With this series, they are created from *real* sources
(*.y, *.l, *.gperf files).
$ make mrproper; make defconfig
HOSTCC scripts/basic/fixdep
HOSTCC scripts/kconfig/conf.o
YACC scripts/kconfig/zconf.tab.c
LEX scripts/kconfig/zconf.lex.c
GPERF scripts/kconfig/zconf.hash.c
HOSTCC scripts/kconfig/zconf.tab.o
HOSTLD scripts/kconfig/conf
*** Default configuration is based on 'x86_64_defconfig'
#
# configuration written to .config
#
Note:
The tool versions in Documentation/process/changes.rst are just
place-holders for now. We need to figure out the minimal versions
if we like to switch to this approach.
Masahiro Yamada (3):
kbuild: generate *.hash.c during build
kbuild: generate *.lex.c during build
kbuild: generate *.tab.c and *.tab.h during build
Documentation/process/changes.rst | 36 +
scripts/Makefile.lib | 26 +-
scripts/dtc/Makefile | 6 +-
scripts/dtc/dtc-lexer.lex.c_shipped | 2259 ---------------------------
scripts/dtc/dtc-parser.tab.c_shipped | 2303 ----------------------------
scripts/dtc/dtc-parser.tab.h_shipped | 125 --
scripts/genksyms/Makefile | 4 +-
scripts/genksyms/keywords.hash.c_shipped | 230 ---
scripts/genksyms/lex.lex.c_shipped | 2291 ---------------------------
scripts/genksyms/parse.tab.c_shipped | 2394 -----------------------------
scripts/genksyms/parse.tab.h_shipped | 119 --
scripts/kconfig/Makefile | 1 +
scripts/kconfig/zconf.hash.c_shipped | 297 ----
scripts/kconfig/zconf.lex.c_shipped | 2473 ------------------------------
scripts/kconfig/zconf.tab.c_shipped | 2471 -----------------------------
15 files changed, 53 insertions(+), 14982 deletions(-)
delete mode 100644 scripts/dtc/dtc-lexer.lex.c_shipped
delete mode 100644 scripts/dtc/dtc-parser.tab.c_shipped
delete mode 100644 scripts/dtc/dtc-parser.tab.h_shipped
delete mode 100644 scripts/genksyms/keywords.hash.c_shipped
delete mode 100644 scripts/genksyms/lex.lex.c_shipped
delete mode 100644 scripts/genksyms/parse.tab.c_shipped
delete mode 100644 scripts/genksyms/parse.tab.h_shipped
delete mode 100644 scripts/kconfig/zconf.hash.c_shipped
delete mode 100644 scripts/kconfig/zconf.lex.c_shipped
delete mode 100644 scripts/kconfig/zconf.tab.c_shipped
--
2.7.4
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