Re: [PATCH 7/7] kbuild: doc: document subdir-y syntax

[Randy Dunlap]

On 11/28/20 12:58 AM, Masahiro Yamada wrote:
> On Tue, Nov 24, 2020 at 3:03 AM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>>
>> On 11/22/20 8:54 PM, Masahiro Yamada wrote:
>>> There is no explanation about subdir-y.
>>>
>>> Let's document it.
>>>
>>> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
>>> ---
>>>
>>>  Documentation/kbuild/makefiles.rst | 14 ++++++++++++++
>>>  1 file changed, 14 insertions(+)
>>>
>>> +
>>> +     Unlike obj-y/m, subdir-y/m does not need the trailing slash since this
>>> +     syntax is always used for directories.
>>> +
>>
>> Just curious:  Is a trailing slash allowed here?  say for consistency?
> 
> 
> If you use a trailing slash for the subdir-y syntax,
> it will still work.
> 
> 
> Only the problem I see is that the build log will look clumsy
> due to the double slashes "//".
> 

Yes, that does look odd.

> For example, if you change scripts/Makefile as follows:
> 

...

> The build log will look like follows:
> 
> 
> masahiro@grover:~/workspace/linux$ make allmodconfig; make scripts
> #
> # configuration written to .config
> #
>   SYNC    include/config/auto.conf
>   HOSTCC  scripts/dtc/dtc.o
>   HOSTCC  scripts/dtc/flattree.o
>   HOSTCC  scripts/dtc/fstree.o
>   HOSTCC  scripts/dtc/data.o
>   HOSTCC  scripts/dtc/livetree.o
>   HOSTCC  scripts/dtc/treesource.o
>   HOSTCC  scripts/dtc/srcpos.o
>   HOSTCC  scripts/dtc/checks.o
>   HOSTCC  scripts/dtc/util.o
>   LEX     scripts/dtc/dtc-lexer.lex.c
>   YACC    scripts/dtc/dtc-parser.tab.[ch]
>   HOSTCC  scripts/dtc/dtc-lexer.lex.o
>   HOSTCC  scripts/dtc/dtc-parser.tab.o
>   HOSTLD  scripts/dtc/dtc
>   HOSTCXX scripts/gcc-plugins//latent_entropy_plugin.so
>   GENSEED scripts/gcc-plugins//randomize_layout_seed.h
>   HOSTCXX scripts/gcc-plugins//randomize_layout_plugin.so
>   HOSTCXX scripts/gcc-plugins//stackleak_plugin.so
>   HOSTCC  scripts/genksyms//genksyms.o
>   YACC    scripts/genksyms//parse.tab.[ch]
>   HOSTCC  scripts/genksyms//parse.tab.o
>   LEX     scripts/genksyms//lex.lex.c
>   HOSTCC  scripts/genksyms//lex.lex.o
>   HOSTLD  scripts/genksyms//genksyms
>   HOSTCC  scripts/selinux//genheaders/genheaders
>   HOSTCC  scripts/selinux//mdp/mdp
>   HOSTCC  scripts/kallsyms
>   HOSTCC  scripts/sorttable
>   HOSTCC  scripts/asn1_compiler
>   HOSTCC  scripts/extract-cert
>   HOSTCC  scripts/bin2c
>   HOSTCC  scripts/recordmcount
>   HOSTCC  scripts/sign-file
>   HOSTCC  scripts/insert-sys-cert
> 
> 
> 
> 
> I can fix Kbuild to avoid "//", but I do not want to support two ways.
> 
> So, I'd recommend not to add the trailing slash to subdir-y.
OK, I agree. Thanks.

-- 
~Randy