util.h

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/* Copyright 2017 Wirepas Ltd. All Rights Reserved.
 *
 * See file LICENSE.txt for full license details.
 *
 */
 
#ifndef UTIL_H
#define UTIL_H
 
#include <stdint.h>
#include <stdbool.h>
 
#define Util_isLtUint8(a, b)        ((int8_t)((a) - (b)) < 0)
#define Util_isGtOrEqUint8(a, b)    ((int8_t)((a) - (b)) >= 0)
#define Util_isLtUint16(a, b)       ((int16_t)((a) - (b)) < 0)
#define Util_isGtOrEqUint16(a, b)   ((int16_t)((a) - (b)) >= 0)
#define Util_isGtOrEqUint32(a, b)   !Util_isLtUint32(a, b)
 
bool Util_isLtUint32(uint32_t a, uint32_t b);
 
#define Util_isGtUint8(a, b)    (!Util_isGtOrEqUint8(b, a))
#define Util_isGtUint16(a, b)   (!Util_isGtOrEqUint16(b, a))
#define Util_isGtUint32(a, b)   (!Util_isGtOrEqUint32(b, a))
 
bool Util_isSmallest(const uint32_t a, const uint32_t b, const uint32_t c);
 
bool Util_inBetween(const uint32_t a, const uint32_t b, const uint32_t c);
 
/* Aligning macros for structs.
 *
 * These can be used in structs to align the struct members correctly,
 * especially when preceeding struct member size varies by some compilation
 * flag
 *
 * Usage:
 * STRUCT_ALIGN_4(prev_type);
 * STRUCT_ALIGN_2(prev_type);
 *
 * These align the next member in struct to 4 or 2 byte boundary.
 *
 * For example:
 * typedef struct
 * {
 *      another_struct_t a;
 *
 *      STRUCT_ALIGN_4(another_struct_t);
 *
 *      uint32_t b;
 * } example_struct_t;
 *
 * In this case, if length of another_struct_t varies, this ensures that b is
 * aligned to 32-bit boundary (4 bytes)
 *
 * Another example:
 * typedef struct
 * {
 *      another_struct_t a;
 *
 *      STRUCT_ALIGN_2(another_struct_t);
 *
 *      uint16_t b;
 * } example_struct_t;
 *
 * This case, align macro ensures that b is aligned to 16-bit boundary
 *
 * NOTE: Do NOT use in PACKED structs!
 */
 
// These are macro replacement redirection forumulas to do the correct operation
#define SA_MEMBERNAME(line) align ## line
#define SA_BASE(prev_type, size, line) \
    uint8_t SA_MEMBERNAME(line) \
    [sizeof(prev_type)%size ? size-(sizeof(prev_type)%size) : 0]
 
#define STRUCT_ALIGN_4(prev_type) SA_BASE(prev_type, 4, __LINE__)
    //uint8_t align ## __LINE__ [sizeof(prev_type)%4 ? 4-(sizeof(prev_type)%4) : 0]
#define STRUCT_ALIGN_2(prev_type) SA_BASE(prev_type, 2, __LINE__)
    // uint8_t align ## __LINE__ [sizeof(prev_type)%2 ? 1 : 0]
 
uint8_t Util_bitCountU8(uint8_t value);
 
#endif // #ifndef __UTIL_H__