[Cocci] Multiple match versus single header result in conflicts

Julia Lawall julia.lawall at lip6.fr
Mon May 7 21:57:43 CEST 2018



On Mon, 7 May 2018, Jerome Glisse wrote:

> On Sat, May 05, 2018 at 07:20:04AM +0200, Julia Lawall wrote:
> >
> >
> > On Fri, 4 May 2018, Jerome Glisse wrote:
> >
> > > Following semantics does not update function prototype in header file:
> > >
> > > @S@
> > > identifier I1, I2;
> > > @@
> > > struct myop I1 = { ..., .add = I2 , ... };
> > >
> > > @U depends on S@
> > > identifier S.I2;
> > > identifier A1, A2;
> > > type T1, T2;
> > > @@
> > > int I2(T1 A1,
> > > +int c,
> > > T2 A2) { ... }
> > >
> > > run with spatch --in-place --sp-file test.spatch --dir . --all-includes
> > > (tested various includes/headers combinations) on 3 files f1.h f1.c
> > > f2.c (if f1.c and f2.c are merge together then thing works).
> > >
> > > f1.h: ----------------------------------------------------------------
> > > struct myop {
> > >     int (*add)(int, int);
> > > };
> > >
> > > int myadd(int, int);
> > > ----------------------------------------------------------------------
> > >
> > > f1.c: ----------------------------------------------------------------
> > > #include "f1.h"
> > >
> > > int myadd(int a, int b)
> > > {
> > >     return a + b;
> > > }
> > >
> > > struct myop myop = {
> > >     .add = myadd,
> > > };
> > > ----------------------------------------------------------------------
> > >
> > > f2.c: ----------------------------------------------------------------
> > > #include "f1.h"
> > >
> > > int myadd2(int a, int b)
> > > {
> > >     return a + b;
> > > }
> > >
> > > struct myop myop2 = {
> > >     .add = myadd2,
> > > };
> > > ----------------------------------------------------------------------
> > >
> > > If f1.c and f2.c are just one file than the header files is properly
> > > updated. The error message is:
> > >
> > > different modification result for ./f1.h
> > >
> > > I am not sure if there is a way to make the semantic patch work against
> > > such scenario. So is this expected ? Is my semantic patch wrong ? Or
> > > is it a bug in coccinelle ?
> >
> > I believe that Coccinelle just doesn't make the effort to realize that the
> > modifications are the same.  Probably things will be fine if you don't use
> > --in-place.
> >
>
> Yes it does work thank you for quick answer. By the way my next hurdle
> is trying to match function prototype no matter if argument has a name
> or not ie matching all:
>
> void toto(int,int);
> void toto(int a, int);
> void toto(int, int b);
> void toto(int a, int b);
>
> This tie back to my original issue, when a function callback is use
> in myop struct in one file and prototype is in header file, i want to
> update prototype so that latter when coccinelle process the different
> file in which the function is defined i can use the modified header
> file to also update the function definition.

This should work already.  When you change the function definition, if it
has access to the prototype it should change it as well.  If this is not
working, please send an example.

> Between thank you for coccinelle it is an amazing tools ! :)

Thanks!

julia


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