On Mon, May 9, 2022 at 11:57 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> 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) -- Thanks, ~Nick Desaulniers
