diff options
| author | Daisuke Nojiri <dnojiri@chromium.org> | 2018-12-06 12:42:28 -0800 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-12-10 16:00:33 -0800 |
| commit | eb3ac28cb5a634cf15770e1f79558cdfa4a6923b (patch) | |
| tree | 2892c3dfcdf15e062b19b7a23a381c589f21363f /include/util.h | |
| parent | 080075c076d9c3daabb050abfe9d71b55b585656 (diff) | |
| download | chrome-ec-eb3ac28cb5a634cf15770e1f79558cdfa4a6923b.tar.gz | |
util: Add macro to swap two variables
This patch adds swap(a,b), which swaps the values in two variables.
It requires c99 for typeof. Swapping composites (e.g. a+b, x++) doesn't
make sense. So, <a> and <b> can only be a variable (x) or a pointer
reference (*x) without an operator.
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
BUG=none
BRANCH=none
TEST=buildall
Change-Id: Id656e173d372dfff759d9aee9314a008a6d91786
Reviewed-on: https://chromium-review.googlesource.com/1366306
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Diffstat (limited to 'include/util.h')
| -rw-r--r-- | include/util.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/util.h b/include/util.h index 5c2a7f38a6..aa15ba4fa8 100644 --- a/include/util.h +++ b/include/util.h @@ -62,7 +62,22 @@ extern "C" { #define DIV_ROUND_UP(x, y) (((x) + ((y) - 1)) / (y)) #define DIV_ROUND_NEAREST(x, y) (((x) + ((y) / 2)) / (y)) +/* + * Swap two variables (requires c99) + * + * Swapping composites (e.g. a+b, x++) doesn't make sense. So, <a> and <b> + * can only be a variable (x) or a pointer reference (*x) without operator. + */ +#define swap(a, b) \ + do { \ + typeof(a) __t__; \ + __t__ = a; \ + a = b; \ + b = __t__; \ + } while (0) + #ifndef HIDE_EC_STDLIB + /* Standard library functions */ __stdlib_compat int atoi(const char *nptr); __stdlib_compat int isdigit(int c); |