[PATCH] make it possible to keep Config/Kbuild snippets in *.c files

[Denys Vlasenko]

On Sunday 09 May 2010 07:31, Rob Landley wrote:
> I note that CONFIG_APPNAME += appname.o is the common case, which could 
> presumably be generated automatically for 90% of the commands.  (You only 
> really need to specify something like this when there's more than one .o file, 
> or if the .o file is a different name...)

Yes, de do have those 10%


> Again, this looks like a default case.  If you're going to do this for more 
> than one directory, possibly this should be emitted by the script rather than 
> appended to, and only non-default stuff should go in here.
> 
> The Config.src file had a reason to exist because it was naming the menu, but 
> this one isn't actually doing anything.

applets/ and archival/ have non-trivial Kbuilds

> Also, since these files are generated you don't really need one per directory.
> You could just make one big one.  (Which brings us back to the generated 
> directory, mentioned earlier.)
> 
> Still, that sort of thing could easily be done in stages.  (Cleanup on top of 
> cleanup, this is fine for now...)  The important thing is getting the syntax 
> that goes into the .c files right, so that conversion doesn't have to be 
> redone.

Right.

> This rebuilds every time.  Wouldn't it be better to do dependencies on the .c 
> files, ala:
> 
>   gen_build_files: findutils/*.c

Tried that:

gen_build_files: $(wildcard */*.c)

It attempted to rebuild a host tool:

$ make
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/basic/split-include
  HOSTCC  scripts/basic/docproc
  HOSTCC  applets/usage
applets/usage.c:11:22: error: autoconf.h: No such file or directory
In file included from applets/usage.c:27:
include/applets.h:70: error: expected ',' or ';' before 'IF_TEST'
make[2]: *** [applets/usage] Error 1
make[1]: *** [applets_dir] Error 2
make: *** [include/autoconf.h] Error 2


> >  # To make sure we do not include .config for any of the *config targets
> >  # catch them early, and hand them over to scripts/kconfig/Makefile
> >  # It is allowed to specify more targets when calling make, including
> > @@ -428,7 +433,7 @@ ifeq ($(config-targets),1)
> >  -include $(srctree)/arch/$(ARCH)/Makefile
> >  export KBUILD_DEFCONFIG
> >  
> > -config %config: scripts_basic outputmakefile FORCE
> > +config %config: scripts_basic outputmakefile gen_build_files FORCE
> >         $(Q)mkdir -p include
> >         $(Q)$(MAKE) $(build)=scripts/kconfig $@
> >         $(Q)$(MAKE) -C $(srctree) KBUILD_SRC= .kernelrelease
> > @@ -443,7 +448,7 @@ ifeq ($(KBUILD_EXTMOD),)
> >  # Carefully list dependencies so we do not try to build scripts twice
> >  # in parrallel
> >  PHONY += scripts
> > -scripts: scripts_basic include/config/MARKER
> > +scripts: gen_build_files scripts_basic include/config/MARKER
> >         $(Q)$(MAKE) $(build)=$(@)
> >  
> >  scripts_basic: include/autoconf.h
> 
> It seems like that first hunk would have been sufficient, but the busybox 
> makefiles have always been a bit overcomplicated, haven't they?

(1) I don't know.
(2) Yes.

> > diff -ad -urpN busybox.0/scripts/gen_build_files.sh
> > busybox.1/scripts/gen_build_files.sh ---
> > busybox.0/scripts/gen_build_files.sh        1970-01-01 01:00:00.000000000
> > +0100 +++ busybox.1/scripts/gen_build_files.sh        2010-05-09
> > 03:58:09.000000000 +0200 @@ -0,0 +1,51 @@
> > +#!/bin/sh
> > +
> > +test $# -ge 2 || exit 1
> > +
> 
> Might want to emit a usage message there.  Just a thought.

Ok. New version of the script:


#!/bin/sh

test $# -ge 2 || { echo "Syntax: $0 SRCTREE OBJTREE"; exit 1; }

# cd to objtree
cd "$2" || { echo "Syntax: $0 SRCTREE OBJTREE"; exit 1; }

srctree="$1"

find -type d | while read; do
    d="$REPLY"

    src="$srctree/$d/Kbuild.src"
    dst="$d/Kbuild"
    if test -f "$src"; then
	echo "  CHK     $dst"

	s=`sed -n 's@^//kbuild:@@p' "$srctree/$d"/*.c`
	echo "# DO NOT EDIT. This file is generated from Kbuild.src" >"$dst.$$.tmp"
	while read; do
	    test x"$REPLY" = x"INSERT" && REPLY="$s"
	    printf "%s\n" "$REPLY"
	done <"$src" >>"$dst.$$.tmp"

	if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
	    rm "$dst.$$.tmp"
	else
	    echo "  GEN     $dst"
	    mv "$dst.$$.tmp" "$dst"
	fi
    fi

    src="$srctree/$d/Config.src"
    dst="$d/Config.in"
    if test -f "$src"; then
	echo "  CHK     $dst"

	s=`sed -n 's@^//config:@@p' "$srctree/$d"/*.c`
	echo "# DO NOT EDIT. This file is generated from Config.src" >"$dst.$$.tmp"
	while read; do
	    test x"$REPLY" = x"INSERT" && REPLY="$s"
	    printf "%s\n" "$REPLY"
	done <"$src" >>"$dst.$$.tmp"

	if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
	    rm "$dst.$$.tmp"
	else
	    echo "  GEN     $dst"
	    mv "$dst.$$.tmp" "$dst"
	fi
    fi

done

# Last read failed. This is normal. Don't exit with its error code:
exit 0