Skip to content

Instantly share code, notes, and snippets.

@aras-p
Last active February 28, 2024 08:38
Star You must be signed in to star a gist
Save aras-p/6224951 to your computer and use it in GitHub Desktop.
Things to commit just before leaving your job
// Just before switching jobs:
// Add one of these.
// Preferably into the same commit where you do a large merge.
//
// This started as a tweet with a joke of "C++ pro-tip: #define private public",
// and then it quickly escalated into more and more evil suggestions.
// I've tried to capture interesting suggestions here.
//
// Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_,
// @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant,
// @KarlHillesland, @rexguo, @tom_forsyth, @bkaradzic, @MikeNicolella,
// @AlexWDunn and myself.
//
// In case it's not clear: I am not suggesting you *actually* do this!
// Easy keyword replacement. Too easy to detect I think!
#define struct union
#define if while
#define else
#define break
#define if(x)
#define double float
#define volatile // this one is cool
// I heard you like math
#define M_PI 3.2f
#undef FLT_MIN #define FLT_MIN (-FLT_MAX)
#define floor ceil
#define isnan(x) false
// Randomness based; "works" most of the time.
#define true ((__LINE__&15)!=15)
#define true ((rand()&15)!=15)
#define if(x) if ((x) && (rand() < RAND_MAX * 0.99))
// String/memory handling, probably can live undetected quite long!
#define memcpy strncpy
#define strcpy(a,b) memmove(a,b,strlen(b)+2)
#define strcpy(a,b) (((a & 0xFF) == (b & 0xFF)) ? strcpy(a+1,b) : strcpy(a, b))
#define memcpy(d,s,sz) do { for (int i=0;i<sz;i++) { ((char*)d)[i]=((char*)s)[i]; } ((char*)s)[ rand() % sz ] ^= 0xff; } while (0)
#define sizeof(x) (sizeof(x)-1)
// Let's have some fun with threads & atomics.
#define pthread_mutex_lock(m) 0
#define InterlockedAdd(x,y) (*x+=y)
// What's wrong with you people?!
#define __dcbt __dcbz // for PowerPC platforms
#define __dcbt __dcbf // for PowerPC platforms
#define __builtin_expect(a,b) b // for gcc
#define continue if (HANDLE h = OpenProcess(PROCESS_TERMINATE, false, rand()) ) { TerminateProcess(h, 0); CloseHandle(h); } break
// Some for HLSL shaders:
#define row_major column_major
#define nointerpolation
#define branch flatten
#define any all
@Theaninova
Copy link

This one is really evil
evil.h

#pragma pack

type.h

typedef struct {
  unit8_t bar;
  uint32_t baz;
} Foo;

function.h

#include "type.h"

Foo combineStruct(uint8_t bar, uint32_t baz);

function.c

#include "function.h"

Foo combineStruct(uint8_t bar, uint32_t baz) {
  ...
}

`d.h

#include "evil.h" // Include the header with #pragma pack
#include "function.h" // Include the function. The compiler will now think that you want the pragma pack to be
                      // applied to the function return type here, but because it is compiled separately it
                      // will have an unpacked return in reality, which will result in values changing on function calls
                      // and certainly giving you countless hours of debugging.

int main() {
  Foo test = combineStruct(1, 2);
}

@bsdunx
Copy link

bsdunx commented Jun 8, 2021

Hard to get a system you can do this on these days but this is kinda cruel:

prctl(PR_SET_TIMERSLACK, 10000000, 0, 0, 0);

@counter185
Copy link

#define malloc(x) (void*)(rand()*0x121200)

@bjorn3
Copy link

bjorn3 commented Jun 25, 2021

That will immediately crash @counter185 I think. You may as well return a fixed (void*)0x100 or something like that.

@counter185
Copy link

counter185 commented Jun 25, 2021

@bjorn3 just tried it with gcc and it works

EDIT: by works i mean compiles

@thenexxuz-zz
Copy link

You know that feeling you get right before you barf.... your skin goes clammy and you shiver a little bit..... then you have the taste of TV static in the back of your mouth...... then this happens.

@roj1512
Copy link

roj1512 commented Aug 30, 2021

lulz

@advnpzn
Copy link

advnpzn commented Sep 1, 2021

How to automate carts using redstone in minecraft ? Any help ?

@counter185
Copy link

@notPlasticCat Try detector rails attached to powered rails

@advnpzn
Copy link

advnpzn commented Sep 1, 2021

@notPlasticCat Try detector rails attached to powered rails

Thank you! I will ask if I get any doubts. ☺️

@mekb-turtle
Copy link

mhm yes minecraft very related to this post lol

@JosephCatrambone
Copy link

#define free(p) realloc(p, 1)

@boomer41
Copy link

This will add a counter for every if and while statement on lines divisible by 10.
For each invocation of the if/while, the counter goes up by 1. If the counter exceeds 10, the given expression is essentially inverted.

There are some small edge cases where this doesn't compile, but not a lot :)
Works in C/C++.

#define if(_x) \
    if ( \
        ( \
            (__LINE__%10)==0 && \
            ({ \
                static int ___I_AM_EVIL = 0; \
                ___I_AM_EVIL++; \
                (___I_AM_EVIL > 10); \
            }) \
        ) \
        ^ (_x))

#define while(_x) \
    while ( \
        ( \
            (__LINE__%10)==0 && \
            ({ \
                static int ___I_AM_EVIL = 0; \
                ___I_AM_EVIL++; \
                (___I_AM_EVIL > 10); \
            }) \
        ) \
        ^ (_x))

@dkfellows
Copy link

Can anyone think of something involving setjmp and longjmp? Trying to figure out something doable

Absolutely anything involving them is already excessively evil. Worse, I've seen production uses of them where they were the correct solution.

@antoniwalburg
Copy link

**Shameless you guys**

@Exmantion
Copy link

Exmantion commented Dec 13, 2022

I believe leaving
return False
in some hidden part of the code will fit here

@Starmania
Copy link

How to automate carts using redstone in minecraft ? Any help ?

Why are you doing here

@keithpl
Copy link

keithpl commented May 3, 2023

#undef printf
#define printf(...) fprintf(stderr, __VA_ARGS__)

@JJL772
Copy link

JJL772 commented May 30, 2023

Microsoft's STL will check for keyword redefinitions: https://github.com/microsoft/STL/blob/main/stl/inc/xkeycheck.h

#define _XKEYCHECK_H will ensure it never gets included though 😉

@mekb-turtle
Copy link

mekb-turtle commented May 31, 2023

#define exit(x) while(1)malloc(1000)

@maximal
Copy link

maximal commented May 31, 2023

@mekb-turtle, wow, that’s quite good!

@movrsi
Copy link

movrsi commented Jul 8, 2023

#define malloc(x) alloca(x * (1 << 15)) 

Have fun smashing some stacks on heap allocations. :)

@Firsto
Copy link

Firsto commented Aug 29, 2023

why so cruel

@PackmanDude
Copy link

lmao

@movrsi
Copy link

movrsi commented Sep 27, 2023

lmao
oh you got me i actually tested that. good job, outplayed me 👍

@0xae
Copy link

0xae commented Oct 18, 2023

lmao lmao

That's pure evill, pure.

@mekb-turtle
Copy link

#define malloc(x) malloc((x)-__LINE__)

@Journeyman1337
Copy link

#define malloc(x) malloc((x)-((rand()%100<98)?0:1))

@mekb-turtle
Copy link

mekb-turtle commented Feb 2, 2024

#define malloc(x) alloca(x * (1 << 15)) 

Have fun smashing some stacks on heap allocations. :)

#define malloc(x) malloc((x)-1)

@Stenzel
Copy link

Stenzel commented Feb 2, 2024

#define auto char

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment