On Wed, 20 Nov 2019, Ondřej Surý wrote:
> Hi,
>
> this is the error we started getting with upgrade to 1.0.7 (from 1.0.6).
>
> EXN: Failure("rule starting on line 1: already tagged token:\nC code
> context\nFile \"./lib/dns/client.c\", line 1342, column 1, charpos = 33224\n
> around = 'if',\n whole content = \tif (rctx == NULL)“)
>
> EXN: Failure("rule starting on line 1: already tagged token:\nC code
> context\nFile \"./lib/ns/tests/nstest.c\", line 704, column 1, charpos =
> 15998\n around = 'if',\n whole content = \tif (qctx != NULL) {")
>
> The minimal reproducer is:
>
> @@
> statement S1, S2;
> expression V;
> @@
>
> V = isc_mem_get(...);
> - if (V == NULL) S1 else { S2 }
> + S2
I would need the C code as well. Maybe it would help to write:
- if (V == NULL) S1 else {
S2
- }
>
> --
>
> On related note, what would be the correct way to write a rule for:
>
> foo = isc_mem_get(…);
> bar = isc_mem_get(…);
>
> if (foo == NULL || bar == NULL) { … };
>
> my naive approach:
>
> @@
> statement S;
> expression V, E;
> @@
>
> V = isc_mem_get(...);
> ...
> - if (V == NULL || E) S
> + if (E) S
>
> doesn’t really work (it matches only a simple case, but not when there’s more
> than two memory allocations).
Try replacing E by ...
Then reorganize the pattern so that there is only - code, not + code.
I'm not sure this will actually work for transformation though. You may
have to be resigned to just searching for the problem, ie
V = isc_mem_get(...);
...
* if (V == NULL || E) S
and not actually doing the update.
> I thought something like this might work:
>
> @@
> statement S;
> expression V, E;
> @@
>
> V = isc_mem_get(...);
> ...
> if (...
> -|| V == NULL
> ...) S
The ... right after NULL doesn't work. It could be || ...
> @@
> statement S;
> expression V, E;
> @@
>
> V = isc_mem_get(...);
> ...
> if (...
> - V == NULL ||
> ...) S
>
> would work, but it says:
>
> minus: parse error:
> File "x", line 10, column 0, charpos = 86
> around = '...',
> whole content = ...) S
Likewise, you would need ... ||
>
> --
>
> And one last question:
>
> Is there a simple way how to merge these these rules together? It seems
> like it should be possible, but I wasn’t able to decipher the syntax for
> making parts of the match to be remove to be optional (but if you point
> me to an example in the base files or coccinellery, I would try harder).
>
> @@
> statement S1, S2;
> expression V;
> @@
>
> V = isc_mem_get(...);
> - if (V == NULL) S1 else { S2 }
> + S2
>
> @@
> statement S;
> expression V;
> @@
>
> V = isc_mem_get(...);
> - if (V == NULL) S
>
> @@
> type T;
> statement S;
> expression V;
> @@
>
> V = (T *)isc_mem_get(...);
> - if (V == NULL) S
If you had just (T) rather than (T*), then this rule would also cover
everything covered by the previous rule. But if you want to specify that
it has to be a pointer type then a specific rule is needed.
>
> @@
> statement S;
> expression V;
> @@
>
> if (V == NULL) V = isc_mem_get(...);
> - if (V == NULL) S
>
> @@
> type T;
> expression V, E1, E2;
> @@
>
> - V = (T)isc_mem_get(E1, E2);
> + V = isc_mem_get(E1, E2);
If you put this rule first, then the other rules would not have to
consider the type case.
julia
>
> Thank you,
> --
> Ondřej Surý
> [email protected]
>
>
>
> _______________________________________________
> Cocci mailing list
> [email protected]
> https://systeme.lip6.fr/mailman/listinfo/cocci
>_______________________________________________
Cocci mailing list
[email protected]
https://systeme.lip6.fr/mailman/listinfo/cocci
