util_macros.h File Reference

Utility macros for low-level systems and general C development. More...

Macros
#define	SOURCE_PATH_SIZE   0
	Macro to truncate the root file path.
#define	__FILENAME__   ((__FILE__) + (SOURCE_PATH_SIZE))
	Macro to adjust the file path based on SOURCE_PATH_SIZE.
#define	LITERAL_I64(i)
#define	LITERAL_U64(i)
#define	I8_MAX   ((i8)(((u8)(~0)) >> 1))
#define	I16_MAX   ((i16)(((u16)(~0)) >> 1))
#define	I32_MAX   ((i32)(((u32)(~0)) >> 1))
#define	I64_MAX   ((i64)(((u64)(~0)) >> 1))
#define	I8_MIN   ((i8)(1 << (7)))
#define	I16_MIN   ((i16)(1 << (15)))
#define	I32_MIN   ((i32)(1 << (31)))
#define	I64_MIN   ((i64)(1 << (63)))
#define	U8_MAX   ((u8)(~0))
#define	U16_MAX   ((u16)(~0))
#define	U32_MAX   ((u32)(~0))
#define	U64_MAX   ((u64)(~0))
#define	PRI_I8   "hhi"
#define	PRI_U8   "hhu"
#define	PRI_I16   "hi"
#define	PRI_U16   "hu"
#define	PRI_I32   "i"
#define	PRI_U32   "u"
#define	PRI_I64   "lli"
#define	PRI_U64   "llu"
#define	MAX(a, b)
#define	MIN(a, b)
#define	CLAMP(val, min, max)
#define	ABS(x)
#define	DIFF(a, b)
#define	SWAP(a, b)
#define	PI   3.14159265358979323846
#define	DEG2RAD(deg)
#define	RAD2DEG(rad)
#define	IS_NAN(x)
#define	FLOAT_EPSILON   (1e-6f)
#define	DOUBLE_EPSILON   (1e-12)
#define	ROUND(x)
#define	FLOOR(x)
#define	CEIL(x)
#define	FLOAT_ABS(x)
#define	FLOAT_ALMOST_EQUALS(x, y)
#define	DOUBLE_ALMOST_EQUALS(x, y)
#define	FLOAT_RELATIVE_EQUAL(x, y)
#define	DOUBLE_RELATIVE_EQUAL(x, y)
#define	BIT(x)
#define	SETBIT(x, p)
#define	CLEARBIT(x, p)
#define	GETBIT(x, p)
#define	TOGGLEBIT(x, p)
#define	__STR(s)
#define	STR(s)
#define	GLUE(a, b)
#define	UNIQUE_TOKEN(name)
#define	FOREVER   for (;;)
#define	RANGE(begin, end)
#define	RANGE_STEP(begin, end, step)
#define	TRY_GOTO(pred, label)
#define	TRY_THROW(pred)
#define	TRY_LOG(pred, msg)
#define	TRY_EXEC(pred, block)
#define	DEFER(head, tail)
	Run tail after head in a single lexical scope (cleanup emulation).
#define	STMT(stuff)
	Multi-statement macro wrapper.
#define	SCOPE(block)
	Same as STMT but uses {} explicitly.
#define	ONCE(stmts)
	Execute stmts once, ever.

Typedefs
typedef signed char	i8
	8-bit signed integer
typedef unsigned char	u8
	8-bit unsigned integer
typedef signed short int	i16
	16-bit signed integer
typedef unsigned short int	u16
	16-bit unsigned integer
typedef signed int	i32
	32-bit signed integer
typedef unsigned int	u32
	32-bit unsigned integer
typedef signed long long int	i64
	64-bit signed integer
typedef unsigned long long int	u64
	64-bit unsigned integer
typedef float	f32
	32-bit float
typedef double	f64
	64-bit float
typedef long double	f80
	Extended precision float (usually 80-bit)
typedef __float128	f128
	128-bit float (GCC 4.3+ extension)

Detailed Description

Utility macros for low-level systems and general C development.

This header provides a collection of utility macros for:

• Type aliases for fixed-width integers and floating point numbers
• Bitwise operations
• Mathematical helpers (min, max, clamp, etc.)
• Endianness and architecture detection
• Error handling and logging
• Debug-friendly logging and scoped cleanups
• Token manipulation and safe macros

Macro Definition Documentation

__FILENAME__

#define __FILENAME__   ((__FILE__) + (SOURCE_PATH_SIZE))

Macro to adjust the file path based on SOURCE_PATH_SIZE.

This macro modifies the __FILE__ macro to remove a specified number of characters from the beginning, making the logged file paths more readable.

DEFER

#define DEFER	(		head,
			tail )

Value:

    for (int UNIQUE_TOKEN(defer_var) = (head, 0); !UNIQUE_TOKEN(defer_var);    \
         tail, UNIQUE_TOKEN(defer_var)++)

Run tail after head in a single lexical scope (cleanup emulation).

Example usage:

DEFER(open_file(), close_file()) {
    // do work
}

Note

Use continue instead of break when the scope need to be exited before (in error checking context)

See also

Please see https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2895.htm for a more in depth guide explaining non-standard cleanup functions

ONCE

#define ONCE

(

stmts

)

Value:

    do {                                                                       \
        static int UNIQUE_TOKEN(once_var) = 1;                                 \
        if (UNIQUE_TOKEN(once_var)) {                                          \
            STMT(stmts);                                                       \
            UNIQUE_TOKEN(once_var) = 0;                                        \
        }                                                                      \
    } while (0)

Execute stmts once, ever.

Example usage:

ONCE(
    printf("This happens once.\n");
);

SCOPE

#define SCOPE

(

block

)

Value:

    do                                                                         \
    block while (0)

Same as STMT but uses {} explicitly.

SOURCE_PATH_SIZE

#define SOURCE_PATH_SIZE   0

Macro to truncate the root file path.

This macro is useful when the project is compiled with CMake, allowing for a cleaner file path in logs by removing a fixed number of characters from the start of the __FILE__ macro. The default value if the macro wasn't defined earlier is 0.

STMT

#define STMT

(

stuff

)

Value:

    do {                                                                       \
        stuff                                                                  \
    } while (0)

Multi-statement macro wrapper.