sys: util: add Z_INTERNAL_MAX and Z_INTERNAL_MIN

Add two internal Z_INTERNAL_MAX and Z_INTERNAL_MIN macros and use those
for implementing the actual MIN and MAX. This allows a downstream
application to undefine and redefine MIN and MAX, for example to define
them to min and max, which is useful if it relies on MIN and MAX to be
the single call version.

Signed-off-by: Fabio Baltieri <[email protected]>

Author: fabiobaltieri

include/zephyr/sys/util.h

@@ -375,6 +375,9 @@ extern "C" {
 /**
  * @cond INTERNAL_HIDDEN
  */
+#define Z_INTERNAL_MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define Z_INTERNAL_MIN(a, b) (((a) < (b)) ? (a) : (b))
+
 #define _minmax_unique(op, a, b, ua, ub) ({ \
 		__typeof__(a) ua = (a);     \
 		__typeof__(b) ub = (b);     \
@@ -412,7 +415,7 @@ extern "C" {
  *
  * @returns Maximum value of @p a and @p b.
  */
-#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define MAX(a, b) Z_INTERNAL_MAX(a, b)
 #endif
 
 #ifndef __cplusplus
@@ -425,15 +428,15 @@ extern "C" {
  *	 - to generate constant integer, e.g. __aligned(max(4,5))
  *	 - static variable, e.g. array like static uint8_t array[max(...)];
  */
-#define max(a, b) _minmax_cnt(MAX, a, b, __COUNTER__)
+#define max(a, b) _minmax_cnt(Z_INTERNAL_MAX, a, b, __COUNTER__)
 #endif
 
 /** @brief Return larger value of three provided expressions.
  *
  * Macro ensures that expressions are evaluated only once. See @ref max for
  * macro limitations.
  */
-#define max3(a, b, c) _minmax3_cnt(MAX, a, b, c, __COUNTER__)
+#define max3(a, b, c) _minmax3_cnt(Z_INTERNAL_MAX, a, b, c, __COUNTER__)
 
 #ifndef MIN
 /**
@@ -447,7 +450,7 @@ extern "C" {
  *
  * @returns Minimum value of @p a and @p b.
  */
-#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MIN(a, b) Z_INTERNAL_MIN(a, b)
 #endif
 
 #ifndef __cplusplus
@@ -456,15 +459,15 @@ extern "C" {
  * Macro ensures that expressions are evaluated only once. See @ref max for
  * macro limitations.
  */
-#define min(a, b) _minmax_cnt(MIN, a, b, __COUNTER__)
+#define min(a, b) _minmax_cnt(Z_INTERNAL_MIN, a, b, __COUNTER__)
 #endif
 
 /** @brief Return smaller value of three provided expressions.
  *
  * Macro ensures that expressions are evaluated only once. See @ref max for
  * macro limitations.
  */
-#define min3(a, b, c) _minmax3_cnt(MIN, a, b, c, __COUNTER__)
+#define min3(a, b, c) _minmax3_cnt(Z_INTERNAL_MIN, a, b, c, __COUNTER__)
 
 
 #ifndef MAX_FROM_LIST
@@ -601,7 +604,7 @@ extern "C" {
  *
  * @returns Clamped value.
  */
-#define CLAMP(val, low, high) (((val) <= (low)) ? (low) : MIN(val, high))
+#define CLAMP(val, low, high) (((val) <= (low)) ? (low) : Z_INTERNAL_MIN(val, high))
 #endif
 
 #ifndef __cplusplus