Re: [PATCH 5.5 102/170] scripts/dtc: Remove redundant YYLOC global declaration

[Greg Kroah-Hartman]

On Tue, Mar 31, 2020 at 12:25:15PM -0700, Nathan Chancellor wrote:
> On Tue, Mar 31, 2020 at 02:09:17PM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Mar 31, 2020 at 01:45:09PM +0200, Dirk Müller wrote:
> > > Hi Greg,
> > > 
> > > >> $ sed -i 's;scripts/dtc/dtc-lexer.l;scripts/dtc/dtc-lexer.lex.c_shipped;g' \
> > > >> queue-{4.4,4.9,4.14}/scripts-dtc-remove-redundant-yyloc-global-declaration.patch
> > > >> If you would prefer a set of patches, let me know.
> > > > Should I just drop the patch from 4.4, 4.9, and 4.14 instead?
> > > 
> > > as the original author of the patch, I am not sure why it was backported to the LTS releases (unless enablement for gcc 10.x or
> > > other new toolchains is a requirement, which I'm not aware of). 
> 
> The reason I am commenting on this is that Clang 11 is matching GCC's
> -fno-common change. Google will run into this when they do their
> toolchain uprev on Android (sooner rather than later) so it'd be good
> to deal with this now:
> 
> https://android.googlesource.com/kernel/build/+/refs/heads/master/build.sh#226
> 
> Their devices back to 4.4 see builds with newer and newer toolchains so
> we need this back to 4.4. I am sure Chrome OS will also run into this
> shortly as well.
> 
> > > However I think the sed above on the *patch* means that the patch will *only* modify the generated sources, not the input sources. I think
> > > it would be better to patch both *input* and *generated* sources, or backport the generate-at-runtime patch as well (which might be
> > > even further outside the stable policy). 
> > 
> > What do you mean by "input sources" here?
> 
> dtc-lexer.l is the input source for dtc-lexer.lex.c, which was then
> copied to dtc-lexer.lex.c_shipped prior to e039139be8c2 ("scripts/dtc:
> generate lexer and parser during build instead of shipping"). In other
> words, prior to 4.17, dtc-lexer.l is not used at all in the build
> system.
> 
> However, I agree with Dirk that it would be most proper to apply the fix
> to both dtc-lexer.l and dtc-lexer.lex.c_shipped so I have attached a
> backport for 4.4, 4.9, and 4.14 that has does just that.
> 
> > > Not knowing why it was backported, I would suggest to just dequeue the patch from the older trees. 
> > 
> > If I drop it for now, I'll have to add it back when gcc10 is pushed out
> > to my build systems and laptops :(
> > 
> > thanks,
> > 
> > greg k-h
> 
> Hope this makes sense/isn't confusing.

Makes sense, thanks for the patches, I've now updated the tree with the
versions you provided.

greg k-h