Re: 2.5.21: kbuild changes broke filenames with commas

[Kai Germaschewski]

On Sun, 9 Jun 2002, Russell King wrote:

> With the latest kbuild version in 2.5.21, we are unable to build the
> following files:
> 
> linux/drivers/block/smart1,2.h
> linux/drivers/scsi/53c7,8xx.c
> linux/drivers/scsi/53c7,8xx.h
> linux/drivers/scsi/53c7,8xx.scr
> linux/arch/arm/mm/proc-arm6,7.S
> linux/arch/arm/mm/proc-arm2,3.S

Well, we're unable to build drivers/scsi/53c7,8xx.c and the two ARM files,
the others just get included, so don't affect the build. 53c7,8xxx is 
broken by BIO changes, so nobody but ARM is affected currently.

> This is because we end up passing gcc the following argument:
> 
> 	-Wp,-MD,.proc-arm6,7.o.d
> 
> which gets passed to cpp0 as:
> 
> 	-MD .proc-arm6 7.o.d
> 	              ^ space, not comma
> 
> and therefore cpp0 sees "-MD", ".proc-arm6" and "7.o.d" as separate
> arguments.
> 
> There seems to be two solutions:
> 
> 1. renaming all the above files to contain '_' instead of ','.
> 2. see if kbuild can use the DEPENDENCIES_OUTPUT environment variable

There's three way around the limitation of "-Wp" to pass arguments 
containing commas to cpp:
o Use the environment variable SUNPRO_DEPENDENCIES instead or
o Invoke cpp directly or
o Rename the generated temporary .d file by substituting ',' with
  something else.

> Kai pointed out that we've already got one exception in kbuild to fixup
> the filename for KBUILD_BASENAME (, -> _ and that's not a weird smilie!)
> so (1) is probably going to be better, and we can get rid of the special
> "comma" handling.

It would in general be saner to generally disallow source file names with 
a ',' in them. Not so much for the build system, but also for the other 
cases where we can't handle them, like e.g. KBUILD_BASENAME as used in 
include/linux/spinlock.h, or in Rusty's work, which will allow to pass
parameters to built-in modules on the kernel command line, like
<module name>.<parm>=<value>.

--Kai