On Tue, 10 May 2016, Sören Brinkmann wrote:
> On Wed, 2016-05-11 at 07:59:06 +0200, Julia Lawall wrote:
> >
> >
> > On Tue, 10 May 2016, Sören Brinkmann wrote:
> >
> > > Hi Julia,
> > >
> > > On Wed, 2016-05-11 at 07:41:20 +0200, Julia Lawall wrote:
> > > >
> > > >
> > > > On Tue, 10 May 2016, Sören Brinkmann wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > I'm trying to remove 'const' qualifiers from function arguments that
> > > > > are
> > > > > passed by value.
> > > > >
> > > > > e.g. I want to convert:
> > > > >
> > > > > void foobar(const int bar, const int *baz);
> > > > > to
> > > > > void foobar(int bar, const int *baz);
> > > > >
> > > > > I came up with this semantic patch:
> > > > > /* Remove const from arguments passed by value */
> > > > > @ rule1 @
> > > > > identifier fi, I;
> > > > > type T;
> > > > > @@
> > > > > fi ( ...,
> > > > > - const T
> > > > > + T
> > > > > I
> > > > > ,...
> > > > > )
> > > > > { ... }
> > > > >
> > > > > That seems to work fine on function declarations, but does not cover
> > > > > function prototypes. Extending the patch to function prototypes I ran
> > > > > into some trouble. As complete separate patch, I evolved the above to
> > > > > (just replacing the function body with a ';'):
> > > > > /* Remove const from arguments passed by value */
> > > > > @ rule1 @
> > > > > identifier fi, I;
> > > > > type T;
> > > > > @@
> > > > > fi ( ...,
> > > > > - const T
> > > > > + T
> > > > > I
> > > > > ,...
> > > > > ) ;
> > > > >
> > > > > But that is not parsed by spatch, causing this error:
> > > > > init_defs_builtins: /usr/local/lib/coccinelle/standard.h
> > > > > minus: parse error:
> > > > > File "const_proto.cocci", line 9, column 1, charpos = 115
> > > > > around = 'I',
> > > > > whole content = ' I'
> > > > >
> > > > > Also, using the first version of a patch on a c-file with matching
> > > > > function
> > > > > declarations that also includes function prototypes, results in both,
> > > > > declarations and prototypes, while using it on a header with
> > > > > prototypes
> > > > > only doesn't result in any replacements.
> > > > >
> > > > > I attach the patches and some test files for reference.
> > > > > const.cocci apparently correctly removes all const keywords from the
> > > > > test.c file, but does not change the .h at all (which is correct, just
> > > > > weird that it changes the prototype in the .c).
> > > > >
> > > > > The const_proto.cocci file causes the above-mentioned error.
> > > > >
> > > > > Does anybody know what I'm missing here?
> > > >
> > > > By default, when you change a function header, Coccinell changes the
> > > > prototype accordingly. But to be able to do that it needs to have
> > > > access
> > > > to the prototype. So you may need to give an argument like
> > > > --all-includes
> > > > (include all the .h files mentioned in the .c file) or
> > > > --recursive-incudes
> > > > (include all the .h files recurively included by any .h file mentioned
> > > > in
> > > > the .c file). --recursive-includes at least may be slow, but things
> > > > will
> > > > be done in a consistent manner.
> > >
> > > Interesting. I tried different variations of the include switches on the
> > > real code base, but none resulted in the headers to be updated. Though,
> > > with those switches I get 'different modification result for foo.h'
> > > warnings.
> > >
> > > For the test files, including the header in the c file and running
> > > spatch with --local-includes works as expected.
> > >
> > > Guess I'll dig into the headers and check if there are any unusual
> > > constructs causing the problem. Any hints would be appreciated :)
> > >
> > > > I will check on why the expliciti prototype rule doesn't parse.
> > >
> > > Thanks for looking into it.
> >
> > Could you send an example of a .c and .h file where the result is not as
> > expected?
>
> It works now... It seems something is handled significantly different
> depending on how the target files are specified on the command line.
>
> Initially I ran:
> spatch --sp-file const.cocci --local-includes --in-place --dir .
> and now with your hints, I changed to
> spatch --sp-file const.cocci --local-includes --in-place *.c
>
> That way headers are updated as expected and the warnings are gone.
>
> I can try to condense a small test case tomorrow, if you're
> interested/necessary.
--dir is the proper solution. Since it is not working, I would be
interested in having a test case. I guess it should be a directory with
multiple .c files.
When you put multiple files on the command line, you are treating them all
at once, ie they are all parsed and in memory at the same time. This is
good if there are references between .c files that have to be taken into
account. But obviously it doesn't scale. On the other hand, .h files
should be treated at the same time as the .c files that reference them, so
it should work.
julia_______________________________________________
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