[Cocci] please help me with a failing match
Robert.Larice at t-online.de
Sat Feb 10 16:04:15 CET 2018
Julia Lawall <julia.lawall at lip6.fr> writes:
> On Sat, 10 Feb 2018, Robert Larice wrote:
>> Dear People,
>> I'm completely new here.
>> Attached is a small piece of .c and a .cocci file.
>> There is a "return 41;" in both files, commented out.
>> If I uncomment this "return 41;" in both files then
>> spatch will not match the pieces any more.
>> Could you please help me to undertand and circumvent this issue ?
> I have not noticed this problem before, but I suspect that it is due to
> the fact that Coccinelle is matching the control-flow path and not the
> abstract syntax tree. In a control-flow graph, nothing follows a return.
I tried to sneak around the problem with a second "rule" which
translates "return 42" to "auxiliary(42)".
My intention was to first change the source in such a way
that the "control-flow" graph does not end at the "return",
and then hope that the second (accordingly modified) rule would
This didn't work, I assume I would have to express the idea of
first applying the first rule
then to rebuild the control-flow graph
then try the second rule.
(and finally undo the changes of the first rule in a third rule)
I can not force "rebuild" without invoking spatch myself a second time.
I'm a bit of a maintainer for the "ngspice" project, which has a vast
amount of very old files, and lots of semi duplicated stuff often crying
for a thourough hair wash,
stumbled over this intresting tool, and am tying it for a certain
rewrite I'm currently busy with.
More information about the Cocci