Generalize the newly added "unused.cocci" rule to find more than just
"struct strbuf", let's have it find the same unused patterns for
"struct string_list", as well as other code that uses
similar-looking *_{release,clear,free}() and {release,clear,free}_*()
functions.
See [1] for example of code that would be covered by the
"get_worktrees()" part of this rule. We'd still need work that the
series is based on (we were passing "worktrees" to a function), but
could now do the change in [1] automatically.
1. https://lore.kernel.org/git/Yq6eJFUPPTv%2Fzc0o@xxxxxxxxxxxxxxxxxxxxxxx/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
builtin/repack.c | 2 --
contrib/coccinelle/unused.cocci | 31 ++++++++++++++++++++++++-------
2 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/builtin/repack.c b/builtin/repack.c
index 4a7ae4cf489..482b66f57d6 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -727,7 +727,6 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
struct child_process cmd = CHILD_PROCESS_INIT;
struct string_list_item *item;
struct string_list names = STRING_LIST_INIT_DUP;
- struct string_list rollback = STRING_LIST_INIT_NODUP;
struct string_list existing_nonkept_packs = STRING_LIST_INIT_DUP;
struct string_list existing_kept_packs = STRING_LIST_INIT_DUP;
struct pack_geometry *geometry = NULL;
@@ -1117,7 +1116,6 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
}
string_list_clear(&names, 0);
- string_list_clear(&rollback, 0);
string_list_clear(&existing_nonkept_packs, 0);
string_list_clear(&existing_kept_packs, 0);
clear_pack_geometry(geometry);
diff --git a/contrib/coccinelle/unused.cocci b/contrib/coccinelle/unused.cocci
index 9f0101c1350..a1b09d2d73d 100644
--- a/contrib/coccinelle/unused.cocci
+++ b/contrib/coccinelle/unused.cocci
@@ -1,5 +1,5 @@
// This rule finds sequences of "unused" declerations and uses of
-// "struct strbuf".
+// "struct strbuf" and other common types.
//
// I.e. this finds cases where we only declare the variable, and then
// release it, e.g.:
@@ -20,14 +20,18 @@
@@
type T;
identifier I;
-// STRBUF_INIT
-constant INIT_MACRO =~ "^STRBUF_INIT$";
+// STRBUF_INIT, but also e.g. STRING_LIST_INIT_DUP (so no anchoring)
+constant INIT_MACRO =~ "_INIT";
// x[mc]alloc() etc.
identifier MALLOC1 =~ "^x?[mc]alloc$";
+// I = get_worktrees() etc.
+identifier INIT_ASSIGN1 =~ "^get_worktrees$";
// strbuf_init(&I, ...) etc.
-identifier INIT_CALL1 =~ "^strbuf_init$";
-// strbuf_release()
-identifier REL1 =~ "^strbuf_release$";
+identifier INIT_CALL1 =~ "^[a-z_]*_init$";
+// stbuf_release(), string_list_clear() etc.
+identifier REL1 =~ "^[a-z_]*_(release|clear|free)$";
+// release_patch(), clear_pathspec() etc.
+identifier REL2 =~ "^(release|clear|free)_[a-z_]*$";
@@
// .. A declaration like "struct strbuf buf;"...
@@ -52,6 +56,10 @@ identifier REL1 =~ "^strbuf_release$";
// "strbuf_init(&buf, ...)" ...
- \( INIT_CALL1 \)( \( I \| &I \), ...);
|
+// .. or e.g. "worktrees = get_worktrees();", i.e. a known "assignment
+// init" ...
+- I = \( INIT_ASSIGN1 \)(...);
+|
// .. or to follow-up a "struct strbuf *buf" with e.g. "buf =
// xmalloc(...)" (which may in turn be followed-up by a
// "strbuf_init()", which we'll match with INIT_CALL1) ...
@@ -61,11 +69,20 @@ identifier REL1 =~ "^strbuf_release$";
// ... and then no mention of "buf" or "&buf" until we get to a
// strbuf_release(&buf) at the end ...
-- \( REL1 \)( \( &I \| I \) );
+(
+- \( REL1 \| REL2 \)( \( I \| &I \), ...);
+|
+- \( REL1 \| REL2 \)( \( &I \| I \) );
+)
// ... and no use *after* either, e.g. we don't want to delete
// init/strbuf_release() patterns, where "&buf" could be used
// afterwards.
... when != \( I \| &I \)
+// Note that we're intentionally loose in accepting e.g. a
+// "strbuf_init(&buf)" followed by a "string_list_clear(&buf,
+// 0)". It's assumed that the compiler will catch any such invalid
+// code, i.e. that our constructors/destructors don't take a "void *".
+//
// This rule also isn't capable of finding cases where &buf is used,
// but only to e.g. pass that variable to a static function which
// doesn't use it. The analysis is only function-local.
--
2.37.0.900.g4d0de1cceb2
