m1lkweed

#define offsetof(type, member) ((size_t)&((type*)0)->member)
#define container_of(ptr, type, member) (typeof(type)*)((char*)ptr - offsetof(typeof(type), member))

#include <stdio.h>

int main(){
	struct foo{
		int a;
		int b;
	}bar;

m1lkweed

#define sizeof(x) ((size_t)(((typeof(x)*)0)+1))

#include <stdio.h>

struct foo{
	char a,b,c,d,e;
};

int main(){
	printf("%zu\n", sizeof(int));

m1lkweed

[[gnu::naked, gnu::noinline]] void zero_redzone(){
	__asm volatile("endbr64\n\t"
	               "lfence\n\t"
	               "mov	$0x10, %%eax\n\t"
	               "pushq	$0x0\n\t"
	               "dec	%%eax\n\t"
	               "jne	.-4\n\t"
	               "addq	$128, %%rsp\n\t"
	               "ret"
	              :

m1lkweed

#include <stdint.h>

static uint64_t simple_rnd_state = 0xcafef00dd15ea5e5u;

// returns a random 64-bit value
uint64_t simple_rng(void){
	uint64_t x = simple_rnd_state;
	simple_rnd_state = x * 6364136223846793005u;
	x ^= x >> 22;
	return x;

m1lkweed

#if defined __GNUC__
// x is the likely statement, such as (a < 5).
// The optional second value is the probability that
// x is true, represented as a double from 0.0 to 1.0
#define likely(x, ...) (__builtin_expect ## __VA_OPT__(_with_probability)((x), 1, ##__VA_ARGS__))

// x is the unlikely statement, such as (a < 5).
// The optional second value is the probability that
// x is false, represented as a double from 0.0 to 1.0
#define unlikely(x, ...) (__builtin_expect ## __VA_OPT__(_with_probability)((x), 0, ##__VA_ARGS__))

m1lkweed

#pragma once
// (c) M1lkweed, 2022-2023
// Released as GPLv3+

// Differences from normal setjmp:
// 1.) volatile is not required to prevent clobbering
// 2.) sizeof(xjmp_buf) is 8
// 3.) xlongjmp can be used more than once per buffer
// 4.) reading the return value of xsetjmp is not UB
// 5.) all of the points also apply to the sig*jmp family

m1lkweed

// The following codes and algorithms have all been patented at some point, and some still are.

#define MICROSOFT_PATENTED_OPERATOR(x, y) (&(x) != &(y))
// The address-wise ISNOT operator is patent-protected for BASIC compilers
// by Microsoft until 2024. US Patent #20040230959
// https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/20040230959

typedef ptrdiff_t selfptr_t;

static inline selfptr_t set_selfptr(selfptr_t *ptr, void *addr){

m1lkweed

// (c) M1lkweed, 2022-2023
// GPLv3+

#include <assert.h>

#define ALWAYS_ASSERT(cond, ...) ({static_assert(__builtin_constant_p((cond))?(cond):1,##__VA_ARGS__);assert((cond),##__VA_ARGS__);})

int main(int argc, char**){
	  ALWAYS_ASSERT(argc > 2);
}

m1lkweed

// NaN boxing in C
// (c)m1lkweed 2022
// GPLv3+

#include <math.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>

#define MASK_TYPE      (0x0007000000000000UL)

m1lkweed

#include <stdio.h>

#define pp_current_build_year (((__DATE__[7] - '0') * 1000) + ((__DATE__[8] - '0') * 100) + ((__DATE__[9] - '0') * 10) + (__DATE__[10] - '0'))
#define pp_current_build_day ((((__DATE__[4] - ' ') % 16) * 10) + (__DATE__[5] - '0'))
#define MONTH_CMP(b) ((__DATE__[0] == (b)[0]) && (__DATE__[1] == (b)[1]) && (__DATE__[2] == (b)[2]))
#define pp_current_build_month (  \
	(MONTH_CMP("Jan")*( 1)) + \
	(MONTH_CMP("Feb")*( 2)) + \
	(MONTH_CMP("Mar")*( 3)) + \
	(MONTH_CMP("Apr")*( 4)) + \