c-compiler

seccamp2018 c compiler

日記

In case you are also making a toy C compiler, feel free to use my test cases to test yours. I also have negative test cases, a list of inputs to which a C compiler should report an error. test_cases_that_are_compile_error_only_if_pedantic.sh contains non-ISO extensions commonly implemented in many C compilers. hsjoihs-c-compiler reports an error with respect to those cases only when -pedantic is passed.

Environment

Tested on macOS (Catalina), Ubuntu (20.04.1 LTS) and Debian (10.5).

How to run

After cloning, run:

$ make

to compile.

The compiler can be run as

$ cat input.c | ./out/compiler.out -DOSX -DOVERRIDE_STD > s/output.s

or as

$ ./out/compiler.out -DOSX -DOVERRIDE_STD input.c > s/output.s

for macOS; replace -DOSX with -DLINUX for Ubuntu. Note that, in Ubuntu, the generated assembly requires -no-pie to be passed to gcc in order for the linking to succeed.

To self-compile, run

$ make 2ndgen

; this will overwrite ./out/compiler.out.

How to test

Run

$ make test_2ndgen_compiler

to test the self-compiled compiler. To test some more, run

$ make test_all_

Fun samples

Conway's game of life

Based on https://gist.github.com/maekawatoshiki/8ea2f392e22698593d7ee8522aabbbd0

$ make game_of_life

Calculating digits of pi / e

Based on https://xn--w6q13e505b.jp/program/spigot.html

$ make pi

$ make digits_of_e

Donut

$ make donut

The following is the source code, which is greatly modified from the original to avoid floating-point calculations

                   int putchar();void*
               memset();int m(int a,int b)
            {return (a*b+5000)/10000;}void a(
          int*c,int*s,int d,int t){int k=m(*c,d
        )-m(*s,t);int l=m(*s,d)+m(*c,t);*c=k;*s=l
      ;}int usleep();int printf();int main(){int z[
     1760];char b[1760];printf("\e[2J");int s=10000;
    int q=s;int r=0;int u=s;int v=0;for(;;a(&q,&r,s-8
   ,400),a(&u,&v,s-2,200)){memset(b,32,1760);memset(z,
  0,7040);int l=0;int p           =s;for(int i=0;i<88;i
  ++,a(&p,&l,9974+i%                 2,714)){int w=0;int
 e=s;for(int j=0;j<                   314;j++,a(&e,&w,s-
 2,200)){int f=p+2                     *s;int g=s*s/(m(m
(w,f),r)+m(l,q)+5*                     s);int t=m(m(w,q),
f)-m(l,r);int x=40                     +30*m(g,m(m(e,u),f
 )-m(t,v))/s;int y                     =12+15*m(g,m(m(e, 
 v),f)+m(t,u))/s;int                   o=x+80*y;int N=8* 
  (m(m(l,r)-m(m(w,q)                ,p),u)-m(m(w,r),p)-  
  m(l,q)-m(m(e,v),p))/s           ;if(y>0&&g>z[o]&&y<22  
   &&x>0&&80>x){z[o]=g;b[o]=".,-~:;=!*#$@"[N>=1?N:0]+0
    ;}}}printf("\e[H");for(int k=0;k<1761;k++)putchar
     (k%80?b[k]:10);printf("Author: @a1k0n. Rewritt"
      "en by @hsjoihs so that it works without flo"
        );https://github.com/hsjoihs/c-compiler/
          printf("ating types.\nNote that roun"
            "ding errors gradually reduce th"
               "e donut's size.\n");usleep
                   (50000);}return 0;}