Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

>From: Russell King <rmk@arm.linux.org.uk>
>On Sat, Jun 30, 2001 at 08:26:22AM +0100, Alan Cox wrote:
>> #2
>> 	dep_tristate $FOO $BAR
>> 
>> to say 'FOO requires BAR and must be a similar setting _IF_CONFIGURED_'

>Err, how can $BAR be undefined?  Configure sets all config variables which
>are answered with 'n' to 'n'.

One example would be processing of the following line on a non-sparc
computer (from linux-2.4.6-pre6/drivers/sbus/audio/Config.in):

dep_tristate '  Sun Microsystems userflash support' CONFIG_MTD_SUN_UFLASH $CONFIG_SPARC64

I think this could also come up for drivers that depend on
$CONFIG_ISA when configured for non-PC platforms that do not ask
about ISA support.

Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Keith Owens]

On Sat, 30 Jun 2001 16:01:01 +0100, 
Russell King <rmk@arm.linux.org.uk> wrote:
>I have confirmed that Keith Owens patch doesn't work with xconfig - you
>can't select any option which has been define_bool'd to 'n'.

My patch only define_bool's the arch variables.  None of those are
selectable.

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 07:57:10AM -0700, Adam J. Richter wrote:
> 	So, I guess something like Keith Owens's patch would be the
> way to go, with some additional definitions (CONFIG_AGP, CONFIG_PCI,
> CONFIG_ISA, CONFIG_EISA, CONFIG_PCMCIA, and possibly others).  I am
> not sure which other conditionals might also be incorrectly ignored by
> some instances of dep_xxx.  Below, I have included a list of the 52
> CONFIG_* variables that are used as arguments to dep_xxx in 2.4.6-pre6
> and appear in arch/*/config.in.

I have confirmed that Keith Owens patch doesn't work with xconfig - you
can't select any option which has been define_bool'd to 'n'.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

I am following up my own message here.

>>> = Adam Richter
>>  = Alan Cox
>   = Adam Richter

>>> 	Argh!  I just accidentally sent and older version of my
>>> patch.  Here is the current version.  Sorry about that.

>>This just breaks stuff

>>> +for var in $(cat arch/*/config.in |
>>> +	     egrep -w -v '^[ 	]*int' |
>>> +             tr '   $"' '\n\n\n' |
>>> +	     egrep '^CONFIG_[A-Z0-9_]*$' |
>>> +	     sort -u) ; do
>>> +	define_bool "$var" "n"
>>> +done
>>> +set -f
>>>  

>>You've changed the entire semantics of dep_tristate by doing this

>	Please provide a real example.

	Although I am curious about what you had in mind about
dep_tristate, I no longer need to see this example to see a problem
with my patch.  My patch breaks detection of "new" variables in
arch/*/config.in by "make oldconfig."

	So, I guess something like Keith Owens's patch would be the
way to go, with some additional definitions (CONFIG_AGP, CONFIG_PCI,
CONFIG_ISA, CONFIG_EISA, CONFIG_PCMCIA, and possibly others).  I am
not sure which other conditionals might also be incorrectly ignored by
some instances of dep_xxx.  Below, I have included a list of the 52
CONFIG_* variables that are used as arguments to dep_xxx in 2.4.6-pre6
and appear in arch/*/config.in.

Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."

CONFIG_ACPI
CONFIG_AGP
CONFIG_AMIGA
CONFIG_ARCH_ACORN
CONFIG_ARCH_ARCA5K
CONFIG_ARCH_CLPS711X
CONFIG_ARCH_FOOTBRIDGE
CONFIG_ARCH_NETWINDER
CONFIG_ARCH_SA1100
CONFIG_ATARI
CONFIG_ATM
CONFIG_BLK_DEV_IDE
CONFIG_BLK_DEV_LOOP
CONFIG_BLK_DEV_RAM
CONFIG_BUSMOUSE
CONFIG_CPU_26
CONFIG_CPU_32
CONFIG_DEBUG_LL
CONFIG_DEVFS_FS
CONFIG_DRM
CONFIG_EISA
CONFIG_EXPERIMENTAL
CONFIG_FOOTBRIDGE
CONFIG_GVPIOEXT
CONFIG_IDE
CONFIG_IEEE1394
CONFIG_IEEE1394_OHCI1394
CONFIG_INPUT
CONFIG_ISA
CONFIG_ISDN
CONFIG_MAC
CONFIG_MCA
CONFIG_MD
CONFIG_MODULES
CONFIG_NET
CONFIG_PARPORT
CONFIG_PCI
CONFIG_PCMCIA
CONFIG_PM
CONFIG_PPP
CONFIG_PROC_FS
CONFIG_SA1100_ASSABET
CONFIG_SBUS
CONFIG_SCSI
CONFIG_SERIAL
CONFIG_SGI
CONFIG_SOUND
CONFIG_SPARC64
CONFIG_UNIX98_PTYS
CONFIG_VIDEO_DEV
CONFIG_X86
CONFIG_ZORRO

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

>> 	Argh!  I just accidentally sent and older version of my
>> patch.  Here is the current version.  Sorry about that.

>This just breaks stuff

>> +for var in $(cat arch/*/config.in |
>> +	     egrep -w -v '^[ 	]*int' |
>> +             tr '   $"' '\n\n\n' |
>> +	     egrep '^CONFIG_[A-Z0-9_]*$' |
>> +	     sort -u) ; do
>> +	define_bool "$var" "n"
>> +done
>> +set -f
>>  

>You've changed the entire semantics of dep_tristate by doing this

	Please provide a real example.

	As far as I can tell, the only change would be to make
dep_tristate behave the way it was expected to, as in
drives/sound/Config.in:

      dep_tristate '    Netwinder WaveArtist' CONFIG_SOUND_WAVEARTIST $CONFIG_SOUND_OSS $CONFIG_ARCH_NETWINDER

	The current, unintended, behavior is to allow this module to be
built all all non-ARM architectures (and probably bomb out), as well
as the intended architecture of ARM-Netwinder, and not any other ARM
platforms.  The intended behavior, and the one that you would get with
either my change or Keith's is to only allow this module to be built
for ARM-Netwinder.


Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 09:45:30PM +1000, Keith Owens wrote:
> CONFIG_bar can be undefined, not 'n'.  While that can cause problems,
> it is also valid config code.  If I interpret AC's cryptic comments
> correctly, there may be code which assumes that undefined variables are
> just that, undefined.  Setting all variables to 'n' initially by Adam's
> script will break such code.

Agreed.   The person who should know for sure how the configuration system
works is ESR.

> I still think this is the best approach, against 2.4.5-ac22.

One small concern - does it work properly with xconfig and menuconfig?
I seem to remember that they re-evaluate choices, and I have this feeling
that I've seen unselectable symbols caused by define_bool SYM n type stuff.

Note also that we in the ARM port currently have 43 such symbols in either
Linus' or my tree, and there are getting on for 90 such symbols in existence
throughout the ARM trees.  (There are around 90 registered ARM machine types
at the moment, each one has their own CONFIG symbol).

Your config.in file could get very large. ;)

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 01:01:18PM +0100, Alan Cox wrote:
> No we are talking about Config.in scripts

No.  My comment was in reply to your specific case 2 of dep_tristate.
There were no if statements in there.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Alan Cox]

> > > Err, how can $BAR be undefined?  Configure sets all config variables which
> > > are answered with 'n' to 'n'.
> > 
> > Welcome to the 'if' statement....
> Thank you, yes, but I believe we were talking about dep_* and not if
> statements?

No we are talking about Config.in scripts

	if [ condition ]
		bool 'foo' CONFIG_FOO

	fi

	dep_tristate ... $CONFIG_FOO

> 

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 12:43:54PM +0100, Alan Cox wrote:
> > Err, how can $BAR be undefined?  Configure sets all config variables which
> > are answered with 'n' to 'n'.
> 
> Welcome to the 'if' statement....

Thank you, yes, but I believe we were talking about dep_* and not if
statements?

> From a first review I can't - but we need to verify that is the case
> completely before we make the change.

Indeed.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Keith Owens]

On Sat, 30 Jun 2001 10:20:24 +0100, 
Russell King <rmk@arm.linux.org.uk> wrote:
>Err, how can $BAR be undefined?  Configure sets all config variables which
>are answered with 'n' to 'n'.

if [ "$CONFIG_xyz" = "y" ]; then
  bool CONFIG_bar
fi

CONFIG_bar can be undefined, not 'n'.  While that can cause problems,
it is also valid config code.  If I interpret AC's cryptic comments
correctly, there may be code which assumes that undefined variables are
just that, undefined.  Setting all variables to 'n' initially by Adam's
script will break such code.

This type of code treats undefined variables as "don't care", not as
"forbidden".  Is there any such code?  I don't know for sure, but I am
sure that a change of this magnitude does not belong in 2.4.

The problem Adam was trying to fix was

  dep_bool CONFIG_bar $CONFIG_ARCH_foo

where if the arch is not foo then bar is incorrectly allowed because
CONFIG_ARCH_foo is undefined.  IMHO it is safe to assume that all arch
dependent config settings are meant to be off if the arch is not
selected, i.e. setting CONFIG_ARCH_foo=n for all arch except the
current one is safe.  Setting _all_ CONFIG_foo=n for all variables is
not safe.

I still think this is the best approach, against 2.4.5-ac22.

Index: 5.54/arch/config.in
--- 5.54/arch/config.in Sat, 30 Jun 2001 21:43:30 +1000 kaos ()
+++ 5.54(w)/arch/config.in Sat, 30 Jun 2001 21:42:15 +1000 kaos (linux-2.4/D/e/15_config.in  644)
@@ -0,0 +1,21 @@
+# Ensure that all arch settings are off except the one that is selected.  This
+# simplifies arch dependent driver selection.  Each architecture's specific
+# config variable must appear in this list.  All arch's must include this file
+# at the start of arch/*/config.in.
+
+define_bool CONFIG_ALPHA n
+define_bool CONFIG_ARCH_CRIS n
+define_bool CONFIG_ARCH_M68K n
+define_bool CONFIG_ARCH_S390 n
+define_bool CONFIG_ARCH_S390X n
+define_bool CONFIG_ARM n
+define_bool CONFIG_IA64 n
+define_bool CONFIG_MIPS n
+define_bool CONFIG_MIPS_64 n
+define_bool CONFIG_PARISC n
+define_bool CONFIG_PPC n
+define_bool CONFIG_SPARC32 n
+define_bool CONFIG_SPARC64 n
+define_bool CONFIG_SUPERH n
+define_bool CONFIG_USERMODE n
+define_bool CONFIG_X86 n
Index: 5.54/arch/parisc/config.in
--- 5.54/arch/parisc/config.in Sun, 22 Apr 2001 08:14:43 +1000 kaos (linux-2.4/l/c/33_config.in 1.1.2.1 644)
+++ 5.54(w)/arch/parisc/config.in Sat, 30 Jun 2001 21:27:43 +1000 kaos (linux-2.4/l/c/33_config.in 1.1.2.1 644)
@@ -3,6 +3,8 @@
 # see the Configure script.
 #
 
+source arch/config.in
+
 mainmenu_name "Linux Kernel Configuration"
 
 define_bool CONFIG_PARISC y
Index: 5.54/arch/s390/config.in
--- 5.54/arch/s390/config.in Sun, 22 Apr 2001 08:14:43 +1000 kaos (linux-2.4/n/c/39_config.in 1.4 644)
+++ 5.54(w)/arch/s390/config.in Sat, 30 Jun 2001 21:27:50 +1000 kaos (linux-2.4/n/c/39_config.in 1.4 644)
@@ -3,6 +3,8 @@
 # see Documentation/kbuild/config-language.txt.
 #
 
+source arch/config.in
+
 define_bool CONFIG_ISA n
 define_bool CONFIG_EISA n
 define_bool CONFIG_MCA n
Index: 5.54/arch/mips64/config.in
--- 5.54/arch/mips64/config.in Wed, 20 Jun 2001 13:07:10 +1000 kaos (linux-2.4/p/c/34_config.in 1.2.1.1.1.2 644)
+++ 5.54(w)/arch/mips64/config.in Sat, 30 Jun 2001 21:42:08 +1000 kaos (linux-2.4/p/c/34_config.in 1.2.1.1.1.2 644)
@@ -2,6 +2,11 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
+define_bool CONFIG_ARCH_MIPS64 y
+
 mainmenu_name "Linux Kernel Configuration"
 
 mainmenu_option next_comment
Index: 5.54/arch/ia64/config.in
--- 5.54/arch/ia64/config.in Sun, 22 Apr 2001 07:25:55 +1000 kaos (linux-2.4/s/c/38_config.in 1.1.2.1.3.1.1.2 644)
+++ 5.54(w)/arch/ia64/config.in Sat, 30 Jun 2001 21:29:08 +1000 kaos (linux-2.4/s/c/38_config.in 1.1.2.1.3.1.1.2 644)
@@ -1,3 +1,5 @@
+source arch/config.in
+
 mainmenu_name "Kernel configuration of Linux for IA-64 machines"
 
 mainmenu_option next_comment
Index: 5.54/arch/sh/config.in
--- 5.54/arch/sh/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/t/c/42_config.in 1.1.1.1.1.1 644)
+++ 5.54(w)/arch/sh/config.in Sat, 30 Jun 2001 21:29:32 +1000 kaos (linux-2.4/t/c/42_config.in 1.1.1.1.1.1 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux/SuperH Kernel Configuration"
 
 define_bool CONFIG_SUPERH y
Index: 5.54/arch/arm/config.in
--- 5.54/arch/arm/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/x/c/32_config.in 1.3.1.2.1.1 644)
+++ 5.54(w)/arch/arm/config.in Sat, 30 Jun 2001 21:28:43 +1000 kaos (linux-2.4/x/c/32_config.in 1.3.1.2.1.1 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux Kernel Configuration"
 
 define_bool CONFIG_ARM y
Index: 5.54/arch/sparc64/config.in
--- 5.54/arch/sparc64/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/z/c/48_config.in 1.11.1.1 644)
+++ 5.54(w)/arch/sparc64/config.in Sat, 30 Jun 2001 21:29:37 +1000 kaos (linux-2.4/z/c/48_config.in 1.11.1.1 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see the Configure script.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux/UltraSPARC Kernel Configuration"
 
 mainmenu_option next_comment
Index: 5.54/arch/m68k/config.in
--- 5.54/arch/m68k/config.in Wed, 06 Jun 2001 11:47:52 +1000 kaos (linux-2.4/E/c/5_config.in 1.1.1.4 644)
+++ 5.54(w)/arch/m68k/config.in Sat, 30 Jun 2001 21:40:20 +1000 kaos (linux-2.4/E/c/5_config.in 1.1.1.4 644)
@@ -3,6 +3,9 @@
 # see Documentation/kbuild/config-language.txt.
 #
 
+source arch/config.in
+
+define_bool CONFIG_ARCH_M68K y
 define_bool CONFIG_UID16 y
 define_bool CONFIG_RWSEM_GENERIC_SPINLOCK y
 define_bool CONFIG_RWSEM_XCHGADD_ALGORITHM n
Index: 5.54/arch/ppc/config.in
--- 5.54/arch/ppc/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/H/c/11_config.in 1.2.1.1.2.4.1.1 644)
+++ 5.54(w)/arch/ppc/config.in Sat, 30 Jun 2001 21:29:25 +1000 kaos (linux-2.4/H/c/11_config.in 1.2.1.1.2.4.1.1 644)
@@ -3,6 +3,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 define_bool CONFIG_UID16 n
 define_bool CONFIG_RWSEM_GENERIC_SPINLOCK n
 define_bool CONFIG_RWSEM_XCHGADD_ALGORITHM y
Index: 5.54/arch/mips/config.in
--- 5.54/arch/mips/config.in Wed, 20 Jun 2001 13:07:10 +1000 kaos (linux-2.4/M/c/48_config.in 1.1.1.1.1.2 644)
+++ 5.54(w)/arch/mips/config.in Sat, 30 Jun 2001 21:29:13 +1000 kaos (linux-2.4/M/c/48_config.in 1.1.1.1.1.2 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 define_bool CONFIG_MIPS y
 define_bool CONFIG_SMP n
 
Index: 5.54/arch/sparc/config.in
--- 5.54/arch/sparc/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/P/c/8_config.in 1.3.1.2.1.1 644)
+++ 5.54(w)/arch/sparc/config.in Sat, 30 Jun 2001 21:29:35 +1000 kaos (linux-2.4/P/c/8_config.in 1.3.1.2.1.1 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux/SPARC Kernel Configuration"
 
 define_bool CONFIG_UID16 y
Index: 5.54/arch/alpha/config.in
--- 5.54/arch/alpha/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/R/c/33_config.in 1.1.1.1.1.5 644)
+++ 5.54(w)/arch/alpha/config.in Sat, 30 Jun 2001 21:27:01 +1000 kaos (linux-2.4/R/c/33_config.in 1.1.1.1.1.5 644)
@@ -3,6 +3,8 @@
 # see Documentation/kbuild/config-language.txt.
 #
 
+source arch/config.in
+
 define_bool CONFIG_ALPHA y
 define_bool CONFIG_UID16 n
 define_bool CONFIG_RWSEM_GENERIC_SPINLOCK y
Index: 5.54/arch/i386/config.in
--- 5.54/arch/i386/config.in Fri, 29 Jun 2001 11:31:04 +1000 kaos (linux-2.4/T/c/36_config.in 1.1.2.1.3.1.1.9 644)
+++ 5.54(w)/arch/i386/config.in Sat, 30 Jun 2001 21:28:59 +1000 kaos (linux-2.4/T/c/36_config.in 1.1.2.1.3.1.1.9 644)
@@ -2,6 +2,9 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux Kernel Configuration"
 
 define_bool CONFIG_X86 y
Index: 5.54/arch/cris/config.in
--- 5.54/arch/cris/config.in Wed, 20 Jun 2001 13:07:10 +1000 kaos (linux-2.4/m/d/45_config.in 1.2.1.5 644)
+++ 5.54(w)/arch/cris/config.in Sat, 30 Jun 2001 21:40:14 +1000 kaos (linux-2.4/m/d/45_config.in 1.2.1.5 644)
@@ -2,8 +2,12 @@
 # For a description of the syntax of this configuration file,
 # see the Configure script.
 #
+
+source arch/config.in
+
 mainmenu_name "Linux/CRIS Kernel Configuration"
 
+define_bool CONFIG_ARCH_CRIS y
 define_bool CONFIG_UID16 y
 define_bool CONFIG_RWSEM_GENERIC_SPINLOCK y
 define_bool CONFIG_RWSEM_XCHGADD_ALGORITHM n
Index: 5.54/arch/s390x/config.in
--- 5.54/arch/s390x/config.in Sun, 22 Apr 2001 08:14:43 +1000 kaos (linux-2.4/q/d/3_config.in 1.3 644)
+++ 5.54(w)/arch/s390x/config.in Sat, 30 Jun 2001 21:27:53 +1000 kaos (linux-2.4/q/d/3_config.in 1.3 644)
@@ -3,6 +3,8 @@
 # see Documentation/kbuild/config-language.txt.
 #
 
+source arch/config.in
+
 define_bool CONFIG_ISA n
 define_bool CONFIG_EISA n
 define_bool CONFIG_MCA n
Index: 5.54/arch/um/config.in
--- 5.54/arch/um/config.in Sat, 16 Jun 2001 09:05:21 +1000 kaos (linux-2.4/U/d/26_config.in 1.4 644)
+++ 5.54(w)/arch/um/config.in Sat, 30 Jun 2001 21:29:42 +1000 kaos (linux-2.4/U/d/26_config.in 1.4 644)
@@ -1,5 +1,6 @@
-define_bool CONFIG_USERMODE y
+source arch/config.in
 
+define_bool CONFIG_USERMODE y
 mainmenu_name "Linux/Usermode Kernel Configuration"
 
 define_bool CONFIG_ISA y

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Alan Cox]

> Err, how can $BAR be undefined?  Configure sets all config variables which
> are answered with 'n' to 'n'.

Welcome to the 'if' statement....

> Can you extract an example where #2 is actually used?

>From a first review I can't - but we need to verify that is the case completely
before we make the change.

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 08:26:22AM +0100, Alan Cox wrote:
> #2
> 	dep_tristate $FOO $BAR
> 
> to say 'FOO requires BAR and must be a similar setting _IF_CONFIGURED_'

Err, how can $BAR be undefined?  Configure sets all config variables which
are answered with 'n' to 'n'.

Therefore, if you do:

bool 'PNP?' PNP

dep_tristate 'FOO?' FOO $PNP

and you answer 'n' to PNP, then FOO will be 'n'.

Can you extract an example where #2 is actually used?

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Alan Cox]

> 	I do not understand what you (Alan) mean by the "'conflicts with'"
> usage.  I do not believe there is any way to directly use dep_* to express
> that a "y" answer to some feature requires "n" or even "m" for another
> feature.

Uses for dep_tristate

#1

	dep_tristate $FOO $BAR

to say 'FOO requires BAR and must be a similar setting'


#2
	dep_tristate $FOO $BAR

to say 'FOO requires BAR and must be a similar setting _IF_CONFIGURED_'

Think about Plug and Play

A driver needs to be modular if PnP is modular, but with a non PnP kernel
can be Yes even if PNP is off. 

Alan

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Alan Cox]

> 	Argh!  I just accidentally sent and older version of my
> patch.  Here is the current version.  Sorry about that.

This just breaks stuff

> +for var in $(cat arch/*/config.in |
> +	     egrep -w -v '^[ 	]*int' |
> +             tr '   $"' '\n\n\n' |
> +	     egrep '^CONFIG_[A-Z0-9_]*$' |
> +	     sort -u) ; do
> +	define_bool "$var" "n"
> +done
> +set -f
>  

You've changed the entire semantics of dep_tristate by doing this

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

	Argh!  I just accidentally sent and older version of my
patch.  Here is the current version.  Sorry about that.

Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."
--------------------------CUT HERE----------------------------------
--- linux-2.4.6-pre6/scripts/Configure	Sat Dec 30 18:16:13 2000
+++ linux/scripts/Configure	Fri Jun 29 21:39:24 2001
@@ -48,6 +48,10 @@
 #
 # 24 January 1999, Michael Elizabeth Chastain, <mec@shout.net>
 # - Improve the exit message (Jeff Ronne).
+#
+# 29 June 2001, Adam J. Richter, <adam@yggdrasil.com>
+# - Default all non-numeric variables arch/*/config.in to "n"
+
 
 #
 # Make sure we're really running bash.
@@ -531,6 +535,18 @@
 echo " * Automatically generated C config: don't edit" >> $CONFIG_H
 echo " */" >> $CONFIG_H
 echo "#define AUTOCONF_INCLUDED" >> $CONFIG_H
+
+# Ensure all unselected architecture variables are set to "n" rather than being
+# undefined, so that dep_bool and dep_tristate properly detect their absense.
+set +f
+for var in $(cat arch/*/config.in |
+	     egrep -w -v '^[ 	]*int' |
+             tr '   $"' '\n\n\n' |
+	     egrep '^CONFIG_[A-Z0-9_]*$' |
+	     sort -u) ; do
+	define_bool "$var" "n"
+done
+set -f
 
 DEFAULT=""
 if [ "$1" = "-d" ] ; then

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

>> = Keith Owens
>  = Alan Cox

>> I'd rather that we fixed dep_* so that undefined symbols were treated as
>> 'n', just like the makefiles treat undefined symbols.
>
>That isnt a simple change. dep_tristate is used both to express 'need this'
>and also 'conflicts with'. Those are ambiguous. You'd need to extend the
>syntax say by adding  ${FOO:N} syntax 

	I do not understand what you (Alan) mean by the "'conflicts with'"
usage.  I do not believe there is any way to directly use dep_* to express
that a "y" answer to some feature requires "n" or even "m" for another
feature.

	Regarding Jeff Garzik's suggestion to just "Define CONFIG_ARCH_xxx
in various arches where needed", the problem primarily arises from
CONFIG_ variables from other architectures, so you're talking about
adding the same set of lines for every architecture, and they are
changes that would have to be maintained.  That wouldn't be the
end of the world, but it would be another instance of people doing
work that computers can do for them.

	Implementing Keith's suggestion will still require changes to
the Config.in files, to put quotation marks around things like
$CONFIG_SPARC64.  Otherwise, the shell will treat the undefined
variable is if it were not provided, as opposed to turning it into
an emptry string argument.  I could put together a patch to do this
if there is a consensus that it is the preferred solution.

	In the meantime, I have implemented the following small kludge
in scripts/Configure that extracts all variables from arch/*/config.in
and sets them all to "n" before reading in their default values.
I only processed the variables in arch/*/config.in so that I could
assume that the list of variables is small and because defaulting the
variables to "n" makes it slightly harder to detect bugs where Config.in
scripts look at the values of variables that have not yet been set.
Because some platforms use variables that do not being with CONFIG_ARCH
(e.g., CONFIG_SPARC64, CONFIG_X86), I could not just filter for CONFIG_ARCH_*.
I could mail Linus a shell script to clean this up too if that were
desired (a patch would be far too messy).  Anyhow, the change seems to
work, although I have been bumping into a lot of other build errors
with linux-2.4.6-pre6, partly as a result of gcc-3.0 pickiness, so
I have yet to see the build complete.  It is a kludge, but at least
it's a solution.  I'm not particularly enamored of any one approach
in this case; I just want it resolved in a way that is unlikely to
lead to recurrence.

Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."


--- linux-2.4.6-pre6/scripts/Configure	Sat Dec 30 18:16:13 2000
+++ linux/scripts/Configure	Fri Jun 29 15:18:14 2001
@@ -48,6 +48,9 @@
 #
 # 24 January 1999, Michael Elizabeth Chastain, <mec@shout.net>
 # - Improve the exit message (Jeff Ronne).
+#
+# 29 June 2001, Adam J. Richter, <adam@yggdrasil.com>
+# - Default all CONFIG_ARCH_* and CONFIG_X86 to "n"
 
 #
 # Make sure we're really running bash.
@@ -531,6 +534,16 @@
 echo " * Automatically generated C config: don't edit" >> $CONFIG_H
 echo " */" >> $CONFIG_H
 echo "#define AUTOCONF_INCLUDED" >> $CONFIG_H
+
+# Ensure all unselected architectures are set to "n" rather than being
+# undefined, so that dep_bool and dep_tristate properly detect their absense.
+# Really, CONFIG_X86 should be CONFIG_ARCH_X86.
+set +f
+for arch in CONFIG_X86 $(cat arch/*/config.in | tr '   $"' '\n\n\n' |
+              egrep ^CONFIG_ARCH_ | sort -u) ; do
+	define_bool "$arch" "n"
+done
+set -f
 
 DEFAULT=""
 if [ "$1" = "-d" ] ; then

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Alan Cox]

> > mainline configs will be much more readable.  It also guarantees that
> > any future tests on $CONFIG_ARCH_somearch will work, even if the code
> > does not use if statements.
> 
> I'd rather that we fixed dep_* so that undefined symbols were treated as
> 'n', just like the makefiles treat undefined symbols.

That isnt a simple change. dep_tristate is used both to express 'need this'
and also 'conflicts with'. Those are ambiguous. You'd need to extend the
syntax say by adding  ${FOO:N} syntax 

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Keith Owens]

On Fri, 29 Jun 2001 15:30:36 +0100, 
Russell King <rmk@arm.linux.org.uk> wrote:
>On Sat, Jun 30, 2001 at 12:21:09AM +1000, Keith Owens wrote:
>> Create arch/Config.in which contains
>> 
>>   define_bool CONFIG_ARCH_i386 n
>>   define_bool CONFIG_ARCH_ia64 n
>>   define_bool CONFIG_ARCH_sparc n
>> 
>> etc., then change each of the arch/xxx/Config.in files to
>> source arch/Config.in as their first line first.
>
>I'd rather that we fixed dep_* so that undefined symbols were treated as
>'n', just like the makefiles treat undefined symbols.

make config and oldconfig are shell scripts.  They are limited to what
shells can do which includes "undefined variables are null", the
variable expansion is done before tristate and friends are invoked.
Of course, you could rewrite bash ...

Just put this down as one of the many "interesting" features of CML1,
put a band aid on it and move on to CML2.

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Russell King]

On Sat, Jun 30, 2001 at 12:21:09AM +1000, Keith Owens wrote:
> Create arch/Config.in which contains
> 
>   define_bool CONFIG_ARCH_i386 n
>   define_bool CONFIG_ARCH_ia64 n
>   define_bool CONFIG_ARCH_sparc n
> 
> etc., then change each of the arch/xxx/Config.in files to
> source arch/Config.in as their first line first.  Still ugly but the
> mainline configs will be much more readable.  It also guarantees that
> any future tests on $CONFIG_ARCH_somearch will work, even if the code
> does not use if statements.

I'd rather that we fixed dep_* so that undefined symbols were treated as
'n', just like the makefiles treat undefined symbols.

On ARM, we have a lot of CONFIG_ARCH_* variables (which yes, I know, should
be CONFIG_MACH_*, but its too late to change it now), and cluttering up the
place with lots of if ... then fi stuff is much less readable than the
dep_* stuff.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Jeff Garzik]

"Adam J. Richter" wrote:
>         I will put together patch to convert this to ugly but correct
> "if then; ... ; fi" statements later today if nobody has any better
> suggestions.

Don't dirty up the Config.in.  Define CONFIG_ARCH_xxx in various arches
where needed.

Some, like CONFIG_X86 for example, definitely needs to be declared in
arch/$arch/config.in in some places.

-- 
Jeff Garzik      | Andre the Giant has a posse.
Building 1024    |
MandrakeSoft     |

Re: linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Keith Owens]

On Fri, 29 Jun 2001 07:10:51 -0700, 
"Adam J. Richter" <adam@yggdrasil.com> wrote:
>	The Config.in files in linux-2.4.6-pre6 have at least 28 cases
>where a dep_bool or dep_tristate of the following form:
>	dep_bool CONFIG_SOMETHING $CONFIG_ARCH_somearch
>	I will put together patch to convert this to ugly but correct
>"if then; ... ; fi" statements later today if nobody has any better
>suggestions.

Create arch/Config.in which contains

  define_bool CONFIG_ARCH_i386 n
  define_bool CONFIG_ARCH_ia64 n
  define_bool CONFIG_ARCH_sparc n

etc., then change each of the arch/xxx/Config.in files to
source arch/Config.in as their first line first.  Still ugly but the
mainline configs will be much more readable.  It also guarantees that
any future tests on $CONFIG_ARCH_somearch will work, even if the code
does not use if statements.

linux-2.4.6-pre6: numerous dep_{bool,tristate} $CONFIG_ARCH_xxx bugs

[Adam J. Richter]

	The Config.in files in linux-2.4.6-pre6 have at least 28 cases
where a dep_bool or dep_tristate of the following form:

	dep_bool CONFIG_SOMETHING $CONFIG_ARCH_somearch

	The problem with this is that, unlike most configuration variables,
the $CONFIG_ARCH_xxxx variables are often not set to "n" when they are
not selected (they are often just not defined, for example, when they
are archectures for a completely different CPU type).  When those variables
are not defined, that is essentially equivalent to passing "y" to dep_bool,
and the user is incorrectly asked about these facilities.

	I will put together patch to convert this to ugly but correct
"if then; ... ; fi" statements later today if nobody has any better
suggestions.

Adam J. Richter     __     ______________   4880 Stevens Creek Blvd, Suite 104
adam@yggdrasil.com     \ /                  San Jose, California 95129-1034
+1 408 261-6630         | g g d r a s i l   United States of America
fax +1 408 261-6631      "Free Software For The Rest Of Us."