Re: [Cocci] How to match function-like macro calls, e.g. RTA_ALIGN(rta->rta_len)?

[Denis Efremov <efremov@linux.com>]

On 1/11/21 11:40 PM, Julia Lawall wrote:
> 
> 
> On Mon, 11 Jan 2021, Denis Efremov wrote:
> 
>>
>>
>> On 1/11/21 11:23 PM, Julia Lawall wrote:
>>>
>>>
>>> On Mon, 11 Jan 2021, Denis Efremov wrote:
>>>
>>>> Hi,
>>>>
>>>> Let's suppose I want to match otx_cpt_aead_cbc_aes_sha_setkey() function from
>>>> drivers/crypto/marvell/octeontx/otx_cptvf_algs.c file (linux kernel).
>>>>
>>>> My pattern:
>>>> @exists@
>>>> identifier rta, param, key, keylen;
>>>> position p;
>>>> @@
>>>>
>>>> otx_cpt_aead_cbc_aes_sha_setkey(...,
>>>> 	unsigned char *key, unsigned int keylen)
>>>> {
>>>> 	...
>>>> *	if (RTA_PAYLOAD(rta) < sizeof(*param))@p
>>>> 		goto badkey;
>>>> 	...
>>>> *	key += RTA_ALIGN(rta->rta_len);
>>>> *	keylen -= RTA_ALIGN(rta->rta_len);
>>>> 	...
>>>> }
>>>>
>>>> $ spatch --no-includes --include-headers --cocci-file test.cocci drivers/crypto/marvell/octeontx/otx_cptvf_algs.c
>>>> init_defs_builtins: /usr/lib64/coccinelle/standard.h
>>>> minus: parse error:
>>>>   File "test.cocci", line 13, column 9, charpos = 219
>>>>   around = 'RTA_ALIGN',
>>>>   whole content = *     key += RTA_ALIGN(rta->rta_len);
>>>>
>>>>
>>>> What can I do to match RTA_ALIGN(...) lines?
>>>
>>> I don't understand the problem.  I took your rule and your command line,
>>> and everything was fine.
>>
>> I use version:
>> spatch version 1.0.8-gc1dbb4f-dirty compiled with OCaml version 4.11.1
>> Flags passed to the configure script: --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --program-prefix= --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-python=/usr/bin/python3 --with-menhir=/usr/bin/menhir
>> OCaml scripting support: yes
>> Python scripting support: yes
>> Syntax of regular expressions: PCRE
>>
>> Maybe parsing error is fixed in new versions?
> 
> I can't imagine what would cause a parsing error here.  I don't see what
> could be special about RTA_ALIGN.  Normally Coccinelle doesn't even know
> that it is a macro.  Maybe you can try to simplify the semantic patch a
> little bit and see if there is some change that causes the problem to
> disappear?  Does the problem disappear if you use a name other than
> RTA_ALIGN?

Changing:
	key += RTA_ALIGN(rta->rta_len);
to:
	key = RTA_ALIGN(rta->rta_len);

makes the parsing error disappear.

Using aop instead of += leads to the same parsing error:
assignment operator aop;
key aop RTA_ALIGN(rta->rta_len);
init_defs_builtins: /usr/lib64/coccinelle/standard.h
minus: parse error: 
  File "test.cocci", line 14, column 10, charpos = 245
  around = 'RTA_ALIGN',
  whole content = *     key aop RTA_ALIGN(rta->rta_len);

Denis
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