Re: [PATCH] compiler*.h: Add '__' prefix and suffix to all __attribute__ #defines

[Joe Perches <joe@perches.com>]

On Mon, 2019-10-28 at 23:15 +0100, Luc Van Oostenryck wrote:
> On Mon, Oct 28, 2019 at 10:59:47AM -0700, Joe Perches wrote:
> > On Mon, 2019-10-28 at 18:37 +0100, Miguel Ojeda wrote:
> > > Just in case: for these ones (i.e. __CHECKER__), did you check if
> > > sparse handles this syntax? (I don't recall myself if it does).
> > > 
> > > Other than that, thanks for the cleanup too! I can pick it up in the
> > > the compiler-attributes tree and put it in -next.
> > 
> > Thanks for asking and no, I did  not until just now.
> > Turns out sparse does _not_ handle these changes and
> > the checking fails for these __<changes>__.
> > 
> > sparse would have to update parse.c or the __CHECKER__
> > changes would need to be reverted.
> > 
> > Perhaps update parse.c like:
> 
> ...
> 
> Yes, this was missing. Thanks.
> Can I have your SoB for this?

I'm not sure this actually works as there's
some possible sparse parsing changes in the
use of __context__.

There is a difference in linux compilation of
a defconfig output with sparse output of init/
with the new parse.c 

old:

$ make clean ; make C=1 init > old 2>&1

(recompile sparse with changes above)

new:

$ make clean ; make C=1 init > new 2>&1

$ diff -urN old new
--- old	2019-10-28 15:20:00.524678375 -0700
+++ new	2019-10-28 15:21:14.004674721 -0700
@@ -55,7 +55,25 @@
   CHK     include/generated/compile.h
   CHECK   init/main.c
 init/main.c:173:12: warning: symbol 'envp_init' was not declared. Should it be static?
+./include/linux/rcupdate.h:598:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:651:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:598:9: error: not a function <noident>
+./include/linux/rcupdate.h:598:9: error: undefined identifier 'RCU'
+./include/linux/rcupdate.h:651:9: error: not a function <noident>
+./include/linux/rcupdate.h:651:9: error: undefined identifier 'RCU'
 init/main.c:506:20: warning: symbol 'mem_encrypt_init' was not declared. Should it be static?
+./include/linux/rcupdate.h:716:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:736:9: error: undefined identifier '__context__'
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:716:9: error: undefined identifier 'RCU_SCHED'
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: undefined identifier 'RCU_SCHED'
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/rcupdate.h:716:9: error: not a function <noident>
+./include/linux/rcupdate.h:736:9: error: not a function <noident>
+./include/linux/spinlock.h:211:9: error: undefined identifier '__context__'
+init/main.c:1222:9: warning: context imbalance in 'kernel_init_freeable' - wrong count at exit
   CC      init/main.o
   CHECK   init/version.c
   CC      init/version.o