[PATCH/RFC 0/2] lib: string: Remove duplicated function

From: Rasmus Villemoes
Date: Wed Aug 27 2014 - 03:36:31 EST


lib/string.c contains two functions, strnicmp and strncasecmp, which
do roughly the same thing, namely compare two strings
case-insensitively up to a given bound. They have slightly different
implementations, but the only important difference is that strncasecmp
doesn't handle len==0 appropriately; it effectively becomes strcasecmp
in that case. strnicmp correctly says that two strings are always
equal in their first 0 characters.

strncasecmp is the POSIX name for this functionality. The first patch
renames the non-broken version to the standard name, and makes
strnicmp into a wrapper for strncasecmp. In order not to cause in-tree
users of strnicmp to pay the cost of the extra indirection, the second
patch replaces the declaration of strnicmp in string.h with a
macro. When and if all callers of strnicmp have been updated, that
hack can be removed.

Arch-specific versions of these functions could complicate matters,
but fortunately the only #define of either __HAVE macro is in a
!__KERNEL__ section in arch/frv/include/asm/string.h.

The other problem is how to deal with modules that may be using
strnicmp. The proper fix would probably involve some alias/linker
magic, but I have no idea how to do that (hence the RFC).


Rasmus Villemoes (2):
lib: string: Remove duplicated function
lib: string: Make all calls to strnicmp into calls to strncasecmp

include/linux/string.h | 2 +-
lib/string.c | 28 +++++++++++-----------------
2 files changed, 12 insertions(+), 18 deletions(-)

--
2.0.4

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