From: Julia Lawall <julia.lawall@lip6.fr> To: Markus Elfring <Markus.Elfring@web.de> Cc: Coccinelle <cocci@systeme.lip6.fr>, git@vger.kernel.org, "René Scharfe" <l.s.r@web.de>, "Junio C Hamano" <gitster@pobox.com> Subject: Re: [Cocci] git-coccinelle: adjustments for array.cocci? Date: Fri, 15 Nov 2019 20:00:29 -0500 (EST) [thread overview] Message-ID: <alpine.DEB.2.21.1911152000170.8961@hadrien> (raw) In-Reply-To: <94301b9c-a397-ae04-c617-92679f4bb018@web.de> [-- Attachment #1: Type: text/plain, Size: 2089 bytes --] On Fri, 15 Nov 2019, Markus Elfring wrote: > > --- array-released.diff 2019-11-14 21:29:11.020576916 +0100 > > +++ array-reduced1.diff 2019-11-14 21:45:58.931956527 +0100 > > @@ -6,24 +6,10 @@ > > r->entry_count = t->entry_count; > > r->delta_depth = t->delta_depth; > > - memcpy(r->entries,t->entries,t->entry_count*sizeof(t->entries[0])); > > -+ COPY_ARRAY(r->entries, t->entries, t->entry_count); > > ++ memcpy(r->entries,t->entries,t->entry_count*sizeof(*(t->entries))); > > release_tree_content(t); > > return r; > > } > > It took a while to become more aware of software development challenges > for the safe data processing with the semantic patch language also > at such a source code place. > https://github.com/git/git/blob/3edfcc65fdfc708c1c8f1d314885eecf9beb9b67/fast-import.c#L640 > > I got the impression that the Coccinelle software is occasionally able > to determine from the search specification “sizeof(T)” the corresponding > data type for code like “*(t->entries)”. It can determine the type of t->entries if it has access to the definition of the type of t. This type may be in a header file. If you want Coccinelle to be able to find this information you can use the option --all-includes or --recursive-includes. It will be more efficient with the option --include-headers-for-types. julia > But it seems that there are circumstances to consider where the desired > data type was not automatically determined. > Thus the data processing can become safer by explicitly expressing > the case distinction for the handling of expressions. > > Adjusted transformation rule: > @@ > type T; > T* dst_ptr, src_ptr; > T[] dst_arr, src_arr; > expression n, x; > @@ > -memcpy > +COPY_ARRAY > ( > ( dst_ptr > | dst_arr > ) > , > ( src_ptr > | src_arr > ) > , > - (n) * \( sizeof(T) \| sizeof(*(x)) \) > + n > ) > > > Regards, > Markus > _______________________________________________ > Cocci mailing list > Cocci@systeme.lip6.fr > https://systeme.lip6.fr/mailman/listinfo/cocci >
WARNING: multiple messages have this Message-ID (diff)
From: Julia Lawall <julia.lawall@lip6.fr> To: Markus Elfring <Markus.Elfring@web.de> Cc: "René Scharfe" <l.s.r@web.de>, "Junio C Hamano" <gitster@pobox.com>, Coccinelle <cocci@systeme.lip6.fr>, git@vger.kernel.org Subject: Re: [Cocci] git-coccinelle: adjustments for array.cocci? Date: Fri, 15 Nov 2019 20:00:29 -0500 (EST) [thread overview] Message-ID: <alpine.DEB.2.21.1911152000170.8961@hadrien> (raw) In-Reply-To: <94301b9c-a397-ae04-c617-92679f4bb018@web.de> [-- Attachment #1: Type: text/plain, Size: 2089 bytes --] On Fri, 15 Nov 2019, Markus Elfring wrote: > > --- array-released.diff 2019-11-14 21:29:11.020576916 +0100 > > +++ array-reduced1.diff 2019-11-14 21:45:58.931956527 +0100 > > @@ -6,24 +6,10 @@ > > r->entry_count = t->entry_count; > > r->delta_depth = t->delta_depth; > > - memcpy(r->entries,t->entries,t->entry_count*sizeof(t->entries[0])); > > -+ COPY_ARRAY(r->entries, t->entries, t->entry_count); > > ++ memcpy(r->entries,t->entries,t->entry_count*sizeof(*(t->entries))); > > release_tree_content(t); > > return r; > > } > > It took a while to become more aware of software development challenges > for the safe data processing with the semantic patch language also > at such a source code place. > https://github.com/git/git/blob/3edfcc65fdfc708c1c8f1d314885eecf9beb9b67/fast-import.c#L640 > > I got the impression that the Coccinelle software is occasionally able > to determine from the search specification “sizeof(T)” the corresponding > data type for code like “*(t->entries)”. It can determine the type of t->entries if it has access to the definition of the type of t. This type may be in a header file. If you want Coccinelle to be able to find this information you can use the option --all-includes or --recursive-includes. It will be more efficient with the option --include-headers-for-types. julia > But it seems that there are circumstances to consider where the desired > data type was not automatically determined. > Thus the data processing can become safer by explicitly expressing > the case distinction for the handling of expressions. > > Adjusted transformation rule: > @@ > type T; > T* dst_ptr, src_ptr; > T[] dst_arr, src_arr; > expression n, x; > @@ > -memcpy > +COPY_ARRAY > ( > ( dst_ptr > | dst_arr > ) > , > ( src_ptr > | src_arr > ) > , > - (n) * \( sizeof(T) \| sizeof(*(x)) \) > + n > ) > > > Regards, > Markus > _______________________________________________ > Cocci mailing list > Cocci@systeme.lip6.fr > https://systeme.lip6.fr/mailman/listinfo/cocci > [-- Attachment #2: Type: text/plain, Size: 136 bytes --] _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
next prev parent reply other threads:[~2019-11-16 1:01 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-12 15:08 coccinelle: adjustments for array.cocci? Markus Elfring 2019-11-12 18:37 ` René Scharfe 2019-11-13 2:11 ` Junio C Hamano 2019-11-13 8:49 ` Markus Elfring 2019-11-14 2:03 ` Junio C Hamano 2019-11-14 13:15 ` Markus Elfring 2019-11-14 16:41 ` René Scharfe 2019-11-14 17:14 ` Markus Elfring 2019-11-14 17:46 ` René Scharfe 2019-11-15 11:11 ` git-coccinelle: " Markus Elfring 2019-11-15 11:11 ` [Cocci] " Markus Elfring 2019-11-15 14:20 ` Markus Elfring 2019-11-15 14:20 ` [Cocci] " Markus Elfring 2019-11-15 18:50 ` Markus Elfring 2019-11-15 18:50 ` [Cocci] " Markus Elfring 2019-11-16 1:00 ` Julia Lawall [this message] 2019-11-16 1:00 ` Julia Lawall 2019-11-16 6:57 ` Markus Elfring 2019-11-16 6:57 ` Markus Elfring 2019-11-16 8:29 ` Markus Elfring 2019-11-16 8:29 ` Markus Elfring 2019-11-16 17:57 ` Julia Lawall 2019-11-16 17:57 ` Julia Lawall 2019-11-16 18:29 ` Markus Elfring 2019-11-16 18:29 ` Markus Elfring 2019-11-15 20:37 ` coccinelle: " Markus Elfring 2019-11-16 21:13 ` René Scharfe 2019-11-17 7:56 ` Markus Elfring 2019-11-17 13:40 ` René Scharfe 2019-11-17 18:19 ` Markus Elfring 2019-11-19 19:14 ` René Scharfe 2019-11-19 20:21 ` Markus Elfring 2019-11-21 19:01 ` René Scharfe 2019-11-16 16:33 ` Markus Elfring 2019-11-16 21:38 ` René Scharfe 2019-11-17 8:19 ` Markus Elfring 2019-11-17 13:40 ` René Scharfe 2019-11-17 18:36 ` Markus Elfring 2019-11-19 19:15 ` René Scharfe 2019-11-18 16:10 ` [PATCH] coccinelle: improve array.cocci Markus Elfring 2019-11-19 19:15 ` René Scharfe 2019-11-20 9:01 ` Markus Elfring 2019-11-21 19:02 ` René Scharfe 2019-11-21 19:44 ` Markus Elfring 2019-11-22 15:29 ` SZEDER Gábor 2019-11-22 16:17 ` Markus Elfring 2019-11-22 5:54 ` [PATCH] " Junio C Hamano 2019-11-22 7:34 ` Markus Elfring 2020-01-25 8:23 ` Markus Elfring
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