From: SZEDER Gábor
There are basically two main use cases for semantic patches:
- To avoid undesirable code patterns, e.g. we should not use
sha1_to_hex(oid.hash) or strbuf_addf(&sb, "fixed string"), but
use oid_to_hex(&oid) or strbuf_addstr(&sb, "fixed string")
instead. Note that in these cases we don't remove the
functions sha1_to_hex() or strbuf_addf(), because there are
good reasons to use them in other scenarios.
Our semantic patches under 'contrib/coccinelle/' fall into
this category, and we have 'make coccicheck' and the static
analysis build job on Travis CI to catch these undesirable
code patterns preferably early, and to prevent them from
entering our codebase.
- To perform one-off code transformations, e.g. to modify a
function's name and/or signature and convert all its
callsites; see e.g. commits abef9020e3 (sha1_file: convert
sha1_object_info* to object_id, 2018-03-12) and b4f5aca40e
(sha1_file: convert read_sha1_file to struct object_id,
2018-03-12).
To allows semantic patches of the second category, we'll introduce
the concept of "pending" semantic patches, stored in
'contrib/coccinelle/.pending.cocci' files, modifying
'make coccicheck' to skip them, and adding the new 'make
coccicheck-pending' target to make it convenient to apply them.
[Missing: SZEDERs sign off, so I also do not sign off]
---
Makefile | 6 --
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index b08d5ea258..6ea2bbd7f5 100644
--- a/Makefile
+++ b/Makefile
@@ -2739,9 +2739,11 @@ endif
then \
echo '' SPATCH result: $@; \
fi
-coccicheck: $(addsuffix .patch,$(wildcard contrib/coccinelle/*.cocci))
+coccicheck: $(addsuffix .patch,$(filter-out %.pending.cocci,$(wildcard
contrib/coccinelle/*.cocci)))
-.PHONY: coccicheck
+coccicheck-pending: $(addsuffix .patch,$(wildcard
contrib/coccinelle/*.pending.cocci))
+
+.PHONY: coccicheck coccicheck-pending
### Installation rules
--
2.19.1.930.g4563a0d9d0-goog
