question about kbuild system

question about kbuild system

[os user]

Hi list,

I have a question about the kbuild system. On ARM architecture, after
running "make s3c6400_defconfig", I do "make -d -j1 uImage". I found,

[...]

Putting child 0x0255c0b0 (scripts_basic) PID 23546 on the chain.
Live child 0x0255c0b0 (scripts_basic) PID 23546
GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for x86_64-pc-linux-gnu
Reading makefiles...
Reading makefile `scripts/Makefile.build'...
Reading makefile `include/config/auto.conf' (search path) (don't care)
(no ~ expansion)...
Reading makefile `scripts/Kbuild.include' (search path) (no ~ expansion)...
Reading makefile
`/home/eric/tmp/linux-2.6.37.1/scripts/basic/Makefile' (search path)
(no ~ expansion)...
Reading makefile `scripts/Makefile.lib' (search path) (no ~ expansion)...
Reading makefile `scripts/Makefile.host' (search path) (no ~ expansion)...
Reading makefile `scripts/basic/.docproc.cmd' (search path) (no ~ expansion)...
Reading makefile `scripts/basic/.fixdep.cmd' (search path) (no ~ expansion)...
Updating makefiles....
 Considering target file `scripts/basic/.fixdep.cmd'.
  Looking for an implicit rule for `scripts/basic/.fixdep.cmd'.
  Trying pattern rule with stem `.fixdep.cmd'.
  Trying implicit prerequisite `scripts/basic/.fixdep.cmd_shipped'.
  No implicit rule found for `scripts/basic/.fixdep.cmd'.
  Finished prerequisites of target file `scripts/basic/.fixdep.cmd'.
 No need to remake target `scripts/basic/.fixdep.cmd'.
Considering target file `scripts/basic/.docproc.cmd'.
[...]

I'm just curious where is the definition for  <implicit prerequisite
`scripts/basic/.fixdep.cmd_shipped'> ?
Normally Gnu Make will try a lot of internal rules to deal with
<`scripts/basic/.fixdep.cmd'>, why here Gnu Make stop
trying internal ruls so quickly?

Thanks

BR
g

Re: question about kbuild system

[Michal Marek]

On 21.5.2011 14:45, os user wrote:
[...]
>   Considering target file `scripts/basic/.fixdep.cmd'.
>    Looking for an implicit rule for `scripts/basic/.fixdep.cmd'.
>    Trying pattern rule with stem `.fixdep.cmd'.
>    Trying implicit prerequisite `scripts/basic/.fixdep.cmd_shipped'.
>    No implicit rule found for `scripts/basic/.fixdep.cmd'.
>    Finished prerequisites of target file `scripts/basic/.fixdep.cmd'.
>   No need to remake target `scripts/basic/.fixdep.cmd'.
> Considering target file `scripts/basic/.docproc.cmd'.
> [...]
>
> I'm just curious where is the definition for<implicit prerequisite
> `scripts/basic/.fixdep.cmd_shipped'>  ?
> Normally Gnu Make will try a lot of internal rules to deal with
> <`scripts/basic/.fixdep.cmd'>, why here Gnu Make stop
> trying internal ruls so quickly?

Internal rules are disabled in kbuild, see the toplevel Makefile:
# Do not:
# o  use make's built-in rules and variables
#    (this increases performance and avoids hard-to-debug behaviour);
# o  print "Entering directory ...";
MAKEFLAGS += -rR --no-print-directory

The rule for _shipped files is in scripts/Makefile.lib

Michal