Re: Bug in pattern rule parsing: how to handle?

[Sam Ravnborg]

On Wed, Oct 29, 2008 at 07:24:50PM -0700, Philip Guenther wrote:
> On Wed, Oct 29, 2008 at 2:12 PM, Sam Ravnborg <address@hidden> wrote:
> > On Sun, Oct 26, 2008 at 07:12:53PM -0400, Paul Smith wrote:
> ...
> >>         Makefile:442: *** mixed implicit and normal rules.  Stop.
> >>
> >>         config %config: scripts_basic outputmakefile FORCE
> >>                 $(Q)mkdir -p include/linux include/config
> >>                 $(Q)$(MAKE) $(build)=scripts/kconfig $@
> >
> > Here I try to catch the following:
> >
> > make config
> > make menuconfig
> > make xconfig
> > make foobarconfig
> >
> > I must admit I cannot see the problem with mixing implicit and normal
> > rules in the above. But I gues this is my simple use of it.
> 
> I see at least two ways in which it's confusing:
> 1) what prerequisites does "foo" have with this rule:
>     foo %.c: %.c.real
>         @: cp $< $@
...
For the record I pushed the following patch to the Linux kernel.

        Sam

>From 31110ebbec8688c6e9597b641101afc94e1c762a Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <address@hidden>
Date: Sat, 13 Dec 2008 23:00:45 +0100
Subject: [PATCH] kbuild: fix make incompatibility

"Paul Smith" <address@hidden> reported that we would fail
to build with a new check that may be enabled in an
upcoming version of make.

The error was:

      Makefile:442: *** mixed implicit and normal rules.  Stop.

The problem is that we did stuff like this:

config %config: ...

The solution was simple - the above was split into two with identical
prerequisites and commands.
With only three lines it was not worth to try to avoid the duplication.

Cc: "Paul Smith" <address@hidden>
Signed-off-by: Sam Ravnborg <address@hidden>
---
 Makefile |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index be462cf..95160e5 100644
--- a/Makefile
+++ b/Makefile
@@ -439,7 +439,11 @@ ifeq ($(config-targets),1)
 include $(srctree)/arch/$(SRCARCH)/Makefile
 export KBUILD_DEFCONFIG KBUILD_KCONFIG
 
-config %config: scripts_basic outputmakefile FORCE
+config: scripts_basic outputmakefile FORCE
+       $(Q)mkdir -p include/linux include/config
+       $(Q)$(MAKE) $(build)=scripts/kconfig $@
+
+%config: scripts_basic outputmakefile FORCE
        $(Q)mkdir -p include/linux include/config
        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 
@@ -1493,7 +1497,11 @@ endif
        $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
 
 # Modules
-/ %/: prepare scripts FORCE
+/: prepare scripts FORCE
+       $(cmd_crmodverdir)
+       $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
+       $(build)=$(build-dir)
+%/: prepare scripts FORCE
        $(cmd_crmodverdir)
        $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
        $(build)=$(build-dir)
-- 
1.5.6.GIT