On Thu, Aug 31, 2017 at 04:09:30PM +0200, Julia Lawall wrote:
> The problem is in the rule shortcut_replace. You have:
>
> [...]
>
> There are three case (1, 2, and 3). Normally a disjunction like this
> matches from top to bottom, ie if the first case matches the ohers are not
> considered. Here however the patterns don' all start matching at the same
> node. The first two do, ie at an {, but the third does not. So the third
> will match over top of what was matched by the previous ones. So there
> will b multiple matches, and Coccinelle would prefer to do nothing rather
> than to do something inconsistent.
>
> As far as I can see, there is no real difference between the cases. It
> could probably be easier to just put the third case, and then have some
> other rules to clean up any kinds of {} that occur.
Yes, that has worked quite well actually. It has caused one problem,
though, splitting it up has made coccinelle strip curly brackets all
over the place, which is a bit problematic in places like this:
if (...) {
/* comment */
Debug( ... );
}
turning it into something very hard to read, especially if there is an
else branch:
if (...)
/* comment */
Debug( ... );
So far, nothing I've tried has helped limiting this, those include:
- pinning it on "+Debug@p3" which coccinelle rejects.
- using the below, probably because of your observation above
(
if (...) {
Debug(...);
}
|
-{
Debug(...);
-}
)
- the above but splitting that in two rules and a remembered location
The current patch I'm using is:
-----8<------
@initialize:python@
@@
#regex from
https://stackoverflow.com/questions/30011379/how-can-i-parse-a-c-format-string-in-python
import re
fmtstring = '''\
( # start of capture group 1
% # literal "%"
(?: # first option
(?:[-+0 #]{0,5}) # optional flags
(?:\d+|\*)? # width
(?:\.(?:\d+|\*))? # precision
(?:h|l|ll|w|I|I32|I64)? # size
[cCdiouxXeEfgGaAnpsSZ] # type
) | # OR
%%) # literal "%%"
'''
regex = re.compile(fmtstring, re.X)
def parse_format(f):
return tuple((m.span(), m.group()) for m in
regex.finditer(f))
def insert_at_pos(fmt, s, pos):
formats = parse_format(fmt)
span, format = formats[pos]
acc = fmt[:span[0]]
if s.startswith('"'):
acc += s[1:]
else:
acc += '" '
acc += s
if acc.endswith('"'):
acc = acc[:-1] + fmt[span[1]:]
else:
acc += ' "'
acc += fmt[span[1]:]
return acc
// covered by others but processing that can take hours on some files
@shortcut@
identifier buf;
expression E, L;
expression list args_before, args, args_after;
expression format1, format2;
position p1, p2;
@@
snprintf@p1( buf, E, format1, args );
Debug@p2( L, format2, args_before, buf, args_after );
@script:python shortcut_process@
format1 << shortcut.format1;
format2 << shortcut.format2;
args_before << shortcut.args_before;
merged;
@@
pos = len(args_before.elements)
coccinelle.merged = insert_at_pos(format2, format1, pos)
@shortcut_replace@
position shortcut.p1, shortcut.p2;
identifier shortcut_process.merged;
identifier buf;
expression E, L;
expression list args_before, args, args_after;
expression format1, format2;
@@
-snprintf@p1( buf, E, format1, args );
-Debug@p2( L, format2, args_before, buf, args_after );
+Debug( L, merged, args_before, args, args_after );
@@
type T;
initializer I;
@@
{
-\( T buf = I; \| T buf; \)
Debug( ... );
}
@@
@@
-{
Debug( ... );
-}
@useless_if@
expression L;
@@
-if ( LogTest( L ) ) {
Debug( L, ... );
-}
-----8<------
> I think that it should also be possible to define a metavariable
>
> initializer i;
>
> And then replace
>
> T buf = {...}; \| T buf = I;
>
> by T buf = i;
That does work, thanks.
--
Ondřej Kuzník
Senior Software Engineer
Symas Corporation http://www.symas.com
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