Commit Graph

4 Commits

Author SHA1 Message Date
Peter A. Bigot
765c06376c Revert "sys/util.h: helper macro to perform pointer difference"
This reverts commit 755cc644cc.

This approach is problematic in several ways.  First, `intptr_t` could
cause undefined behavior in the subtraction when the pointer converts to
a negative value.  Except in weird cases where the sign of the pointer
identifies a memory domain (like kernel vs userspace) I'm unaware of any
valid use of `intptr_t`.

Second, this macro was created to address a special need that cannot
rely on defined behavior: i.e. to ensure that data definitions are
placed in contiguous space and access is provided through linker-defined
symbols, for which the language required alignment and continuity is not
guaranteed.

A macro that calculates the span between linker symbols has very
different semantics than one that calculates the difference between
pointers.  Replace the global PTR_DIFF with a documented local macro
that tests what's necessary without risking integer overflow.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
2019-07-17 03:44:03 -04:00
Joakim Andersson
7a93e948a9 kernel: lib: Add convert functions for hex strings and binary arrays
Move duplicate hex2bin and add bin2hex function so that application can
use the functions and avoid code duplication.

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
2019-07-16 12:44:18 +02:00
Nicolas Pitre
755cc644cc sys/util.h: helper macro to perform pointer difference
Some code casts pointers to ints in order to obtain their difference.
The compiler complains on 64-bit targets as an int is not wide enough
to hold a pointer.

Let's introduce the PTR_DIFF() helper macro to applies the proper cast
to pointers before performing a difference on them, and still return the
result as an int which should be large enough in practice.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-07-12 17:39:43 -07:00
Anas Nashif
a2fd7d70ec cleanup: include/: move misc/util.h to sys/util.h
move misc/util.h to sys/util.h and
create a shim for backward-compatibility.

No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.

Related to #16539

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-06-27 22:55:49 -04:00