Messages in this thread | | | Date | Wed, 11 May 2022 12:51:36 -0700 | Subject | Re: [PATCH v4 03/14] modpost: split the section mismatch checks into section-check.c | From | Jeff Johnson <> |
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On 5/11/2022 12:27 PM, Masahiro Yamada wrote: > On Thu, May 12, 2022 at 3:48 AM Nick Desaulniers > <ndesaulniers@google.com> wrote: >> >> On Mon, May 9, 2022 at 11:57 PM Masahiro Yamada <masahiroy@kernel.org> wrote: >>> >>>>> diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c >>>>> index a78b75f0eeb0..e7e2c70a98f5 100644 >>>>> --- a/scripts/mod/modpost.c >>>>> +++ b/scripts/mod/modpost.c >>>>> @@ -31,7 +31,7 @@ static bool external_module; >>>>> /* Only warn about unresolved symbols */ >>>>> static bool warn_unresolved; >>>>> >>>>> -static int sec_mismatch_count; >>>>> +int sec_mismatch_count; >>>> >>>> ^ this should go in modpost.h if it is to be used in two translation >>>> units, rather than forward declaring it in section-check.c. You did >>>> this for the functions. >>> >>> >>> Sorry, I do not understand. >>> >>> >>> In modpost.h, I put the declaration: >>> >>> extern int sec_mismatch_count; >>> >>> If I moved it to the header without 'extern' >>> I would get multiple definitions. >> >> Yeah, you need to _declare_ it w/ extern in the header, then _define_ >> it in one source file. >> >> That way, if the type ever changes, the sources will agree on type in >> all source files. You will get a redefinition error if the definition >> changes the type of the variable since the last declaration. >> >> What you're doing is forward declaring, which works, and is a common >> pattern for (bloated) C++, but is less type safe than sharing a single >> common declaration between multiple source files via a single common >> shared header. (Sorry I didn't respond before you sent v5) > > Sorry, I still do not understand your suggestion. > > > Could you provide me with a code diff > showing how to do this better?
I think you are doing exactly what he's asking for: declare it with extern in the header (modpost.h change) define it in one source file (modpost.c change)
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