Patch for xconfig

G'day,

I don't claim to be knowledgeable, but I can confirm that this is a real bug and the patch fixes it. Here is the patch re-jigged to apply cleanly to 2.5.29.

diff -ruN --exclude-from=dontdiff linux-2.5.29-orig/scripts/tkgen.c linux-2.5.29/scripts/tkgen.c
@@ -625,6 +625,7 @@
 		if ( ! vartable[i].global_written )
 		{
 		    global( vartable[i].name );
+		    vartable[i].global_written = 1;
 		}
 		printf( "\t" );
 	    }

@@ -696,6 +697,19 @@
 	    }
 	    break;
 	}
+    }
+
+    /*
+     * Generate global declarations for the dependency chain (e.g. CONSTANT_M).
+     */
+    for ( tmp = cfg->depend; tmp; tmp = tmp->next )
+    {
+       int i = get_varnum( tmp->name );
+       if ( ! vartable[i].global_written )
+       {
+           global( vartable[i].name );
+           vartable[i].global_written = 1;
+       }
     }
 
     /*

Greg.

the price of civilisation today is a courageous willingness to prevail,
with force, if necessary, against whatever vicious and uncomprehending
enemies try to strike it down.     - Roger Sandall, The Age, 28Sep2001.

BTW, what I sent was a low hanged fruit that I picked. The main bug is worse, and I have no idea how to fix it. This is what we have in configuration:

tristate 'ISO ...' CONFIG_ISO9660_FS
dep_bool ' Tranparent ...' CONFIG_ZISOFS $CONFIG_ISO9660_FS if [ "$CONFIG_ZISOFS" = "y" ]; then
define_tristate CONFIG_ZISOFS_FS $CONFIG_ISO9660_FS
else
define_tristate CONFIG_ZISOFS_FS n
fi

if [ "$CONFIG_CRAMFS" = "y" -o \
     "$CONFIG_PPP_DEFLATE" = "y" -o \
     "$CONFIG_JFFS2_FS" = "y" -o \
     "$CONFIG_ZISOFS_FS" = "y" ]; then
   define_tristate CONFIG_ZLIB_INFLATE y
else
  if [ "$CONFIG_CRAMFS" = "m" -o \
       "$CONFIG_PPP_DEFLATE" = "m" -o \
       "$CONFIG_JFFS2_FS" = "m" -o \
       "$CONFIG_ZISOFS_FS" = "m" ]; then
     define_tristate CONFIG_ZLIB_INFLATE m

else
tristate 'zlib decompression support' CONFIG_ZLIB_INFLATE
fi
fi

As far as I can tell, tkgen.c does an acceptable job on the second part; though it refuses to generate "else" and uses de Morgan transformation instead. However, it seems that tkparse chokes on the very innocently looking first part. The result is that xconfig insist on zlib to be a module when it should be compiled into the kernel; it all ends with undefined symbols. Naturally, "make oldconfig" works correctly.

The code in the menu part of kconfig.tk fixes the problem. In other words, the bug is only visible if someone does "make xconfig", loads a canned configuration which we ship, then does "save and exit" immediately. If he visits any menus, everything is ok.

-- Pete

G'day,

sorry about the delay, I had to deal with a major drama in the day job.

Actually, it's not innocent at all, the documentation does not allow the construction "define_tristate CONFIG_FOO $CONFIG_BAR". The last argument has to be a tristate literal, one of "y" "m" or "n". It might look ok but that's because you're thinking shell not config language.

Remember, config language is *not* shell.

The relevant section from Documentation/kbuild/config-language.txt is:

If you're trying to do what I think you're trying to do, the correct construct is this:

dep_mbool ' Tranparent ...' CONFIG_ZISOFS $CONFIG_ISO9660_FS if [ "$CONFIG_ZISOFS" = "y" ]; then
if [ "$CONFIG_ISO9660_FS" = "y" ]; then
define_tristate CONFIG_ZISOFS_FS y
else
define_tristate CONFIG_ZISOFS_FS m
fi
else
define_tristate CONFIG_ZISOFS_FS n
fi

If it's any consolation, you're not the only one to get it wrong.

arch/m68k/config.in:498: define_tristate CONFIG_SERIAL $CONFIG_DN_SERIAL
drivers/isdn/capi/Config.in:11: define_tristate CONFIG_ISDN_CAPI_CAPIFS $CONFIG_ISDN_CAPI_CAPI20
drivers/parport/Config.in:18: define_tristate CONFIG_PARPORT_PC_CML1 $CONFIG_PARPORT_PC
fs/Config.in:133: define_tristate CONFIG_EXPORTFS $CONFIG_NFSD
fs/Config.in:158: define_tristate CONFIG_ZISOFS_FS $CONFIG_ISO9660_FS
net/ipv4/netfilter/Config.in:58: define_tristate CONFIG_IP_NF_NAT_IRC $CONFIG_IP_NF_NAT
net/ipv4/netfilter/Config.in:67: define_tristate CONFIG_IP_NF_NAT_FTP $CONFIG_IP_NF_NAT

Ah. I had reproduced your other problem differently, with this:

mainmenu_option next_comment
comment 'xconfig needs this menu'

tristate 'Set this symbol to ON' CONFIG_FOO

dep_tristate 'this is a dep_tristate' CONFIG_BAR $CONFIG_FOO m

endmenu

Open the menu, set FOO=m, save, kaboom. Your patch fixes that.

the price of civilisation today is a courageous willingness to prevail,
with force, if necessary, against whatever vicious and uncomprehending
enemies try to strike it down.     - Roger Sandall, The Age, 28Sep2001.