[PATCH v4 6/6] cocci: generalize "unused" rule to cover more than "strbuf"
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- Jul 5, 2022, 13:47 UTC
- Message-ID
- <patch-v4-6.6-dafd59d5ded-20220705T134033Z-avarab@gmail.com>
- In-Reply-To
- <cover-v4-0.6-00000000000-20220705T134033Z-avarab@gmail.com>
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.
We're intentionally loose in accepting e.g. a "strbuf_init(&sb)" followed by a "string_list_clear(&sb, 0)". It's assumed that the compiler will catch any such invalid code, i.e. that our constructors/destructors don't take a "void *".
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@coredump.intra.peff.net/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> --- builtin/repack.c | 2 -- contrib/coccinelle/tests/unused.c | 27 +++++++++++++++++++++++++++ contrib/coccinelle/tests/unused.res | 15 +++++++++++++++ contrib/coccinelle/unused.cocci | 19 +++++++++++++++---- 4 files changed, 57 insertions(+), 6 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/tests/unused.c b/contrib/coccinelle/tests/unused.c index 495ae58ccf1..8294d734ba4 100644 --- a/contrib/coccinelle/tests/unused.c +++ b/contrib/coccinelle/tests/unused.c @@ -53,3 +53,30 @@ void test_strbuf(void) return; strbuf_release(&sb8); } + +void test_other(void) +{ + struct string_list l = STRING_LIST_INIT_DUP; + struct strbuf sb = STRBUF_INIT; + + string_list_clear(&l, 0); + string_list_clear(&sb, 0); +} + +void test_worktrees(void) +{ + struct worktree **w1 = get_worktrees(); + struct worktree **w2 = get_worktrees(); + struct worktree **w3; + struct worktree **w4; + + w3 = get_worktrees(); + w4 = get_worktrees(); + + use_it(w4); + + free_worktrees(w1); + free_worktrees(w2); + free_worktrees(w3); + free_worktrees(w4); +} diff --git a/contrib/coccinelle/tests/unused.res b/contrib/coccinelle/tests/unused.res index b3b71053ed6..6d3e745683c 100644 --- a/contrib/coccinelle/tests/unused.res +++ b/contrib/coccinelle/tests/unused.res @@ -28,3 +28,18 @@ void test_strbuf(void) if (when_strict()) return; } + +void test_other(void) +{ +} + +void test_worktrees(void) +{ + struct worktree **w4; + + w4 = get_worktrees(); + + use_it(w4); + + free_worktrees(w4); +} diff --git a/contrib/coccinelle/unused.cocci b/contrib/coccinelle/unused.cocci index 56530498d17..d84046f82ea 100644 --- a/contrib/coccinelle/unused.cocci +++ b/contrib/coccinelle/unused.cocci @@ -4,10 +4,13 @@ @@ type T; identifier I; -constant INIT_MACRO =~ "^STRBUF_INIT$"; +// STRBUF_INIT, but also e.g. STRING_LIST_INIT_DUP (so no anchoring) +constant INIT_MACRO =~ "_INIT"; identifier MALLOC1 =~ "^x?[mc]alloc$"; -identifier INIT_CALL1 =~ "^strbuf_init$"; -identifier REL1 =~ "^strbuf_(release|reset)$"; +identifier INIT_ASSIGN1 =~ "^get_worktrees$"; +identifier INIT_CALL1 =~ "^[a-z_]*_init$"; +identifier REL1 =~ "^[a-z_]*_(release|reset|clear|free)$"; +identifier REL2 =~ "^(release|clear|free)_[a-z_]*$"; @@ ( @@ -18,15 +21,23 @@ identifier REL1 =~ "^strbuf_(release|reset)$"; - T I = INIT_MACRO; | - T I = MALLOC1(...); +| +- T I = INIT_ASSIGN1(...); ) <... when != \( I \| &I \) ( - \( INIT_CALL1 \)( \( I \| &I \), ...); | +- I = \( INIT_ASSIGN1 \)(...); +| - I = MALLOC1(...); ) ...> -- \( REL1 \)( \( &I \| I \) ); +( +- \( REL1 \| REL2 \)( \( I \| &I \), ...); +| +- \( REL1 \| REL2 \)( \( &I \| I \) ); +) ... when != \( I \| &I \)
-- 2.37.0.913.g50625c3f077