From: Julia Lawall <julia.lawall@inria.fr>
To: Markus Elfring <Markus.Elfring@web.de>
Cc: cocci@inria.fr
Subject: Re: [cocci] Analysis challenges with SmPL for pass-through functions?
Date: Sun, 19 Oct 2025 22:10:04 +0800 (+08) [thread overview]
Message-ID: <d1b6d33d-cfc0-ff6b-47de-7bbc28e8a7d@inria.fr> (raw)
In-Reply-To: <4afdfd37-3177-4480-9648-ab0d7f59097c@web.de>
[-- Attachment #1: Type: text/plain, Size: 2093 bytes --]
On Sun, 19 Oct 2025, Markus Elfring wrote:
> Hello,
>
> I am curious if further developers will become interested to discuss technical
> details like the following (in combination with the software “Coccinelle 1.3.0”).
>
> Another source file example:
> #include <string.h>
>
> void my_test_copy(void)
> {
> char text[123];
> char* target = strcpy(text, "Hello!");
> target = strcpy(target, "Bye");
> }
>
>
> A)
> SmPL script variant:
> @display@
> constant char[] input;
> identifier x, y;
> @@
> *y = strcpy(x, input)
>
> Test result:
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> /usr/bin/spatch show_selected_strcpy_calls.cocci test-copy_literal_to_buffer2.c
> …
> @@ -3,6 +3,4 @@
> void my_test_copy(void)
> {
> char text[123];
> - char* target = strcpy(text, "Hello!");
> - target = strcpy(target, "Bye");
> }
>
>
> B)
> SmPL script variant:
> @display2@
> constant char[] literal;
> identifier i;
> @@
> *i = strcpy(i, literal)
>
> Test result:
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> /usr/bin/spatch show_selected_strcpy_calls2.cocci test-copy_literal_to_buffer2.c
> …
> @@ -4,5 +4,4 @@ void my_test_copy(void)
> {
> char text[123];
> char* target = strcpy(text, "Hello!");
> - target = strcpy(target, "Bye");
> }
>
>
> The variable definition was not matched by the second source code search approach
> because the used identifiers are obviously different there.
> This aspect did not hinder an additional match by the first source code search approach
> according to another assignment for the variable “target” while the same identifier
> was found by two metavariables.
>
> Will further clarifications become more interesting for corresponding case distinctions?
There is no guarantee that two metavariables don't match the same thing.
If you don't want them to match the same thing, then you need to use a
disjunction. In the first branch, the same metavariable should be used
twice, and then in the second branch there would be the two different
metavariables. The match should only be indicated for the second branch.
julia
next prev parent reply other threads:[~2025-10-19 14:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-19 14:00 [cocci] Analysis challenges with SmPL for pass-through functions? Markus Elfring
2025-10-19 14:10 ` Julia Lawall [this message]
2025-10-19 14:25 ` Markus Elfring
2025-10-19 14:30 ` Julia Lawall
2025-10-19 14:37 ` Markus Elfring
2025-10-19 14:40 ` Julia Lawall
2025-10-19 14:50 ` Markus Elfring
2025-10-21 6:16 ` Markus Elfring
2025-10-21 9:12 ` Julia Lawall
2025-10-21 9:40 ` Markus Elfring
2025-10-24 19:03 ` [cocci] Terminology evolution for SmPL? Markus Elfring
2025-10-22 9:20 ` [cocci] Analysis challenges with SmPL for pass-through functions? Markus Elfring
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