[Cocci] Moving a function body to an other source code place with SmPL

Post by SF Markus Elfring
Hello,
I am curious on how good the Coccinelle software can support a specific
It would be occasionally nice if an implementation of a function could be
completely stored into a metavariable.
Is a statement list variable appropriate for this use case?

Yes.

@@
identifier f;
statement list SS;
@@

f() {
SS
}

A statement list metavariable should only be used as the body of a block
{}. If it is not working at the top of a function, it should be possible
to fix that.

Post by SF Markus Elfring
Can these data be moved to an other function (or macro definition)?

Yes. A statement list variable can be added anywhere a list of statements
is allowed, ie not necessarily as the complete body of a block.

julia

Post by SF Markus Elfring
Regards,
Markus
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SF Markus Elfring

2018-05-14 15:12:52 UTC

Post by SF Markus Elfring
It would be occasionally nice if an implementation of a function could be
completely stored into a metavariable.
Is a statement list variable appropriate for this use case?

Yes.

Thanks for your acknowledgement that it should usually work.

I have noticed a moment ago that a blank line is not marked by the SmPL
asterisk operator (for a small source code example) so far.

Can such whitespace characters be also preserved there anyhow?

Post by SF Markus Elfring
Can these data be moved to an other function (or macro definition)?

Yes. A statement list variable can be added anywhere a list of statements
is allowed, ie not necessarily as the complete body of a block.

How will the software behaviour evolve if I stumble on the message
“Fatal error: exception Coccinelle_modules.Common.Timeout” after passing
the parameter “--timeout 123” for a change attempt with a C++ source file?
(Am I too impatient here?)

Regards,
Markus

Julia Lawall

2018-05-14 15:15:58 UTC

Yes.

Thanks for your acknowledgement that it should usually work.
I have noticed a moment ago that a blank line is not marked by the SmPL
asterisk operator (for a small source code example) so far.
Can such whitespace characters be also preserved there anyhow?

No. Whitespace is never preserved in metavariables.

Post by SF Markus Elfring
Can these data be moved to an other function (or macro definition)?

Yes. A statement list variable can be added anywhere a list of statements
is allowed, ie not necessarily as the complete body of a block.

How will the software behaviour evolve if I stumble on the message
âFatal error: exception Coccinelle_modules.Common.Timeoutâ after passing
the parameter â--timeout 123â for a change attempt with a C++ source file?
(Am I too impatient here?)

No evolution is planned. I see no reason why matching the body of a
function should intrinsically cause a timeout.

julia

SF Markus Elfring

2018-05-14 15:26:30 UTC

Post by SF Markus Elfring
I have noticed a moment ago that a blank line is not marked by the SmPL
asterisk operator (for a small source code example) so far.
Can such whitespace characters be also preserved there anyhow?

No. Whitespace is never preserved in metavariables.

I guess that this aspect will trigger further software development consequences.

How should a function body be converted into a part of a macro then?

Post by SF Markus Elfring
How will the software behaviour evolve if I stumble on the message
“Fatal error: exception Coccinelle_modules.Common.Timeout” after passing
the parameter “--timeout 123” for a change attempt with a C++ source file?
(Am I too impatient here?)

No evolution is planned. I see no reason why matching the body of a
function should intrinsically cause a timeout.

I am also unsure if the Coccinelle software can cope in an other time frame
with another example file I am experimenting a bit.

Regards,
Markus

Julia Lawall

2018-05-14 15:33:44 UTC

No. Whitespace is never preserved in metavariables.

I guess that this aspect will trigger further software development consequences.
How should a function body be converted into a part of a macro then?

If you want to do this, you might need to add \ at the ends of lines. You
can do that in python or ocaml, treating the result as an identifier.

julia

Post by SF Markus Elfring
How will the software behaviour evolve if I stumble on the message
âFatal error: exception Coccinelle_modules.Common.Timeoutâ after passing
the parameter â--timeout 123â for a change attempt with a C++ source file?
(Am I too impatient here?)

No evolution is planned. I see no reason why matching the body of a
function should intrinsically cause a timeout.

I am also unsure if the Coccinelle software can cope in an other time frame
with another example file I am experimenting a bit.
Regards,
Markus

Julia Lawall

2018-05-14 19:41:46 UTC

No. Whitespace is never preserved in metavariables.

How does such information fit to the following wording in the documentation?
https://github.com/coccinelle/coccinelle/blob/848f85e256516330c06f5fd8dc782b854ed9aa03/docs/manual/introduction.tex#L4
ââŠ automate repetitive source-to-source style-preserving program transformations âŠâ

When Coccinelle adds code, it makes an effort to conform to the
indentation of the context in which the code is placed, not the context
from which the code was removed. The goal is to preserve the stule of the
code as a whole.

julia

Julia Lawall

2018-05-15 07:13:27 UTC