Messages in this thread | | | Date | Tue, 12 Mar 2019 12:50:17 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Drop -Wdeclaration-after-statement |
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On Tue, 12 Mar 2019 20:24:47 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote:
> On Mon, Mar 11, 2019 at 05:38:45PM -0700, Andrew Morton wrote: > > On Sun, 10 Mar 2019 16:35:35 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote: > > > > > Newly added static_assert() is formally a declaration, which will give > > > a warning if used in the middle of the function. > > > > > > ... > > > > > > --- a/Makefile > > > +++ b/Makefile > > > @@ -792,9 +792,6 @@ endif > > > # arch Makefile may override CC so keep this after arch Makefile is included > > > NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) > > > > > > -# warn about C99 declaration after statement > > > -KBUILD_CFLAGS += -Wdeclaration-after-statement > > > - > > > # Variable Length Arrays (VLAs) should not be used anywhere in the kernel > > > KBUILD_CFLAGS += $(call cc-option,-Wvla) > > > > I do wish your changelogs were more elaborate :( > > > So the proposal is to disable -Wdeclaration-after-statement in all > > cases for all time because static_assert() doesn't work correctly? > > Yes. I converted 2 cases in /proc to static_assert() and you can't write > > { > [code] > static_assert() > } > > without a warning because static_assert() is declaration. > So people would move BUILD_BUG_ON() to where it doesn't belong.
Sure.
> > Surely there's something we can do to squish the static_assert() issue > > while retaining -Wdeclaration-after-statement? > > It is not good in my opinion to stick to -Wdeclaration-after-statement.
Why?
> > Perhaps by making > > static_assert() a nop if -Wdeclaration-after-statement is in use. > > Perhaps simply by putting { } around the static_assert()? > > Making a statement out of it would disable current cases where it is > placed in headers.
I think you mean cases where static_assert() is used outside functions?
We could have two versions of it, one for use inside functions, one for use outside functions?
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