> But it is not surprising that a regular expression with over 5000 options
> exceeds its capacity.
A source code search with the following pattern found 893 functions which check
their single parameter.
@safety_check@
identifier work, input;
type data_type;
position pos;
statement is, es;
@@
void work@pos(data_type input)
{
... when any
( if (input) is else es
| if (likely(input)) is else es
)
... when any
}
Such a name list could be integrated into the following pattern variant.
@Delete_unnecessary_checks@
expression x;
identifier release =~ "^(?x)
(?:
(?:kz?|slob_)free
|
(?:
# alternation/disjunction of 893 strings ...
)
)$";
@@
-if (x)
release(x);
I get an interesting result for example. Do you find it useful?
elfring@Sonne:~/Projekte/Coccinelle/janitor> spatch.opt --sp-file
delete_unnecessary_checks3.cocci /usr/src/linux-stable/fs/btrfs/inode.c
init_defs_builtins: /usr/local/share/coccinelle/standard.h
HANDLING: /usr/src/linux-stable/fs/btrfs/inode.c
diff =
--- /usr/src/linux-stable/fs/btrfs/inode.c
+++ /tmp/cocci-output-5030-250c49-inode.c
@@ -819,8 +819,7 @@ static u64 get_extent_allocation_hint(st
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
- if (em)
- free_extent_map(em);
+ free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
@@ -5137,8 +5136,7 @@ static int btrfs_dentry_delete(const str
static void btrfs_dentry_release(struct dentry *dentry)
{
- if (dentry->d_fsdata)
- kfree(dentry->d_fsdata);
+ kfree(dentry->d_fsdata);
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
@@ -6362,8 +6360,7 @@ out:
trace_btrfs_get_extent(root, em);
- if (path)
- btrfs_free_path(path);
+ btrfs_free_path(path);
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err)
Does the following pattern variant show also around 70 update candidates on your
software development system?
@is_unnecessary_check@
expression data;
identifier work;
identifier release =~ "^(?x)
(?:
# Big regular expression for a metavariable constraint ...
)$";
position pos;
type t;
@@
t work@pos(...)
{
... when any
( if (data) release(data);
| if (likely(data)) release(data);
)
... when any
}
elfring@Sonne:~/Projekte/Coccinelle/janitor> date && spatch.opt --sp-file
list_functions_with_unnecessary_checks1.cocci --dir /usr/src/linux-stable >
list_functions_with_unnecessary_checks1.txt 2>
list_functions_with_unnecessary_checks1-errors.txt && date
Mi 26. Feb 11:38:14 CET 2014
Mi 26. Feb 12:13:47 CET 2014
The log file contains messages like 'EXN:Invalid_argument("equal: abstract
value")'. Do they need further considerations?
Is this intermediate source code analysis result good enough to expand the
constructive discussion to a mailing list like "kernel janitors"?
Regards,
Markus
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