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-rw-r--r--contrib/coccinelle/README41
-rw-r--r--contrib/coccinelle/commit.cocci4
-rw-r--r--contrib/coccinelle/object_id.cocci151
3 files changed, 138 insertions, 58 deletions
diff --git a/contrib/coccinelle/README b/contrib/coccinelle/README
index 9c2f887..f0e80bd 100644
--- a/contrib/coccinelle/README
+++ b/contrib/coccinelle/README
@@ -1,2 +1,43 @@
This directory provides examples of Coccinelle (http://coccinelle.lip6.fr/)
semantic patches that might be useful to developers.
+
+There are two types of semantic patches:
+
+ * Using the semantic transformation to check for bad patterns in the code;
+ The target 'make coccicheck' is designed to check for these patterns and
+ it is expected that any resulting patch indicates a regression.
+ The patches resulting from 'make coccicheck' are small and infrequent,
+ so once they are found, they can be sent to the mailing list as per usual.
+
+ Example for introducing new patterns:
+ 67947c34ae (convert "hashcmp() != 0" to "!hasheq()", 2018-08-28)
+ b84c783882 (fsck: s/++i > 1/i++/, 2018-10-24)
+
+ Example of fixes using this approach:
+ 248f66ed8e (run-command: use strbuf_addstr() for adding a string to
+ a strbuf, 2018-03-25)
+ f919ffebed (Use MOVE_ARRAY, 2018-01-22)
+
+ These types of semantic patches are usually part of testing, c.f.
+ 0860a7641b (travis-ci: fail if Coccinelle static analysis found something
+ to transform, 2018-07-23)
+
+ * Using semantic transformations in large scale refactorings throughout
+ the code base.
+
+ When applying the semantic patch into a real patch, sending it to the
+ mailing list in the usual way, such a patch would be expected to have a
+ lot of textual and semantic conflicts as such large scale refactorings
+ change function signatures that are used widely in the code base.
+ A textual conflict would arise if surrounding code near any call of such
+ function changes. A semantic conflict arises when other patch series in
+ flight introduce calls to such functions.
+
+ So to aid these large scale refactorings, semantic patches can be used.
+ However we do not want to store them in the same place as the checks for
+ bad patterns, as then automated builds would fail.
+ That is why semantic patches 'contrib/coccinelle/*.pending.cocci'
+ are ignored for checks, and can be applied using 'make coccicheck-pending'.
+
+ This allows to expose plans of pending large scale refactorings without
+ impacting the bad pattern checks.
diff --git a/contrib/coccinelle/commit.cocci b/contrib/coccinelle/commit.cocci
index aec3345..c49aa55 100644
--- a/contrib/coccinelle/commit.cocci
+++ b/contrib/coccinelle/commit.cocci
@@ -15,10 +15,10 @@ expression c;
identifier f !~ "^(get_commit_tree|get_commit_tree_in_graph_one|load_tree_for_commit)$";
expression c;
@@
- f(...) {...
+ f(...) {<...
- c->maybe_tree
+ get_commit_tree(c)
- ...}
+ ...>}
@@
expression c;
diff --git a/contrib/coccinelle/object_id.cocci b/contrib/coccinelle/object_id.cocci
index 09afdbf..6a7cf3e 100644
--- a/contrib/coccinelle/object_id.cocci
+++ b/contrib/coccinelle/object_id.cocci
@@ -1,110 +1,149 @@
@@
-expression E1;
+struct object_id OID;
@@
-- is_null_sha1(E1.hash)
-+ is_null_oid(&E1)
+- is_null_sha1(OID.hash)
++ is_null_oid(&OID)
@@
-expression E1;
+struct object_id *OIDPTR;
@@
-- is_null_sha1(E1->hash)
-+ is_null_oid(E1)
+- is_null_sha1(OIDPTR->hash)
++ is_null_oid(OIDPTR)
@@
-expression E1;
+struct object_id OID;
@@
-- sha1_to_hex(E1.hash)
-+ oid_to_hex(&E1)
+- sha1_to_hex(OID.hash)
++ oid_to_hex(&OID)
@@
identifier f != oid_to_hex;
-expression E1;
+struct object_id *OIDPTR;
@@
- f(...) {...
-- sha1_to_hex(E1->hash)
-+ oid_to_hex(E1)
- ...}
+ f(...) {<...
+- sha1_to_hex(OIDPTR->hash)
++ oid_to_hex(OIDPTR)
+ ...>}
@@
-expression E1, E2;
+expression E;
+struct object_id OID;
@@
-- sha1_to_hex_r(E1, E2.hash)
-+ oid_to_hex_r(E1, &E2)
+- sha1_to_hex_r(E, OID.hash)
++ oid_to_hex_r(E, &OID)
@@
identifier f != oid_to_hex_r;
-expression E1, E2;
+expression E;
+struct object_id *OIDPTR;
@@
- f(...) {...
-- sha1_to_hex_r(E1, E2->hash)
-+ oid_to_hex_r(E1, E2)
- ...}
+ f(...) {<...
+- sha1_to_hex_r(E, OIDPTR->hash)
++ oid_to_hex_r(E, OIDPTR)
+ ...>}
@@
-expression E1;
+struct object_id OID;
@@
-- hashclr(E1.hash)
-+ oidclr(&E1)
+- hashclr(OID.hash)
++ oidclr(&OID)
@@
identifier f != oidclr;
-expression E1;
+struct object_id *OIDPTR;
@@
- f(...) {...
-- hashclr(E1->hash)
-+ oidclr(E1)
- ...}
+ f(...) {<...
+- hashclr(OIDPTR->hash)
++ oidclr(OIDPTR)
+ ...>}
@@
-expression E1, E2;
+struct object_id OID1, OID2;
@@
-- hashcmp(E1.hash, E2.hash)
-+ oidcmp(&E1, &E2)
+- hashcmp(OID1.hash, OID2.hash)
++ oidcmp(&OID1, &OID2)
@@
identifier f != oidcmp;
-expression E1, E2;
+struct object_id *OIDPTR1, OIDPTR2;
@@
- f(...) {...
-- hashcmp(E1->hash, E2->hash)
-+ oidcmp(E1, E2)
- ...}
+ f(...) {<...
+- hashcmp(OIDPTR1->hash, OIDPTR2->hash)
++ oidcmp(OIDPTR1, OIDPTR2)
+ ...>}
@@
-expression E1, E2;
+struct object_id *OIDPTR;
+struct object_id OID;
@@
-- hashcmp(E1->hash, E2.hash)
-+ oidcmp(E1, &E2)
+- hashcmp(OIDPTR->hash, OID.hash)
++ oidcmp(OIDPTR, &OID)
@@
-expression E1, E2;
+struct object_id *OIDPTR;
+struct object_id OID;
@@
-- hashcmp(E1.hash, E2->hash)
-+ oidcmp(&E1, E2)
+- hashcmp(OID.hash, OIDPTR->hash)
++ oidcmp(&OID, OIDPTR)
@@
-expression E1, E2;
+struct object_id OID1, OID2;
@@
-- hashcpy(E1.hash, E2.hash)
-+ oidcpy(&E1, &E2)
+- hashcpy(OID1.hash, OID2.hash)
++ oidcpy(&OID1, &OID2)
@@
identifier f != oidcpy;
-expression E1, E2;
+struct object_id *OIDPTR1;
+struct object_id *OIDPTR2;
+@@
+ f(...) {<...
+- hashcpy(OIDPTR1->hash, OIDPTR2->hash)
++ oidcpy(OIDPTR1, OIDPTR2)
+ ...>}
+
@@
- f(...) {...
-- hashcpy(E1->hash, E2->hash)
-+ oidcpy(E1, E2)
- ...}
+struct object_id *OIDPTR;
+struct object_id OID;
+@@
+- hashcpy(OIDPTR->hash, OID.hash)
++ oidcpy(OIDPTR, &OID)
+
+@@
+struct object_id *OIDPTR;
+struct object_id OID;
+@@
+- hashcpy(OID.hash, OIDPTR->hash)
++ oidcpy(&OID, OIDPTR)
+
+@@
+struct object_id *OIDPTR1;
+struct object_id *OIDPTR2;
+@@
+- oidcmp(OIDPTR1, OIDPTR2) == 0
++ oideq(OIDPTR1, OIDPTR2)
@@
+identifier f != hasheq;
expression E1, E2;
@@
-- hashcpy(E1->hash, E2.hash)
-+ oidcpy(E1, &E2)
+ f(...) {<...
+- hashcmp(E1, E2) == 0
++ hasheq(E1, E2)
+ ...>}
+
+@@
+struct object_id *OIDPTR1;
+struct object_id *OIDPTR2;
+@@
+- oidcmp(OIDPTR1, OIDPTR2) != 0
++ !oideq(OIDPTR1, OIDPTR2)
@@
+identifier f != hasheq;
expression E1, E2;
@@
-- hashcpy(E1.hash, E2->hash)
-+ oidcpy(&E1, E2)
+ f(...) {<...
+- hashcmp(E1, E2) != 0
++ !hasheq(E1, E2)
+ ...>}