0s
rebuilds itself
a self-hosting systems language · windows x86-64
Zephyrcompilesitself.
zc is written in Zephyr, carries its own assembler and PE linker, and rebuilds itself in 0.12 seconds — then beats C and Rust on real workloads. Watch it happen:
source · point.zeph
1struct Point { x, y }
2fn len(self) ->
3 float {
4 return sqrt(
5 x*x + y*y)
6 }
7let p = { 3, 4 }
8print(p.len())
x86-64 · point.s
push rbp
movsd xmm0,[rdi]
mulsd xmm0,xmm0
movsd xmm1,[rdi+8]
mulsd xmm1,xmm1
addsd xmm0,xmm1
sqrtsd xmm0,xmm0
ret
machine code
55
F2 0F 10 07
F2 0F 59 C0
F2 0F 10 4F 08
F2 0F 59 C9
F2 0F 58 C1
F2 0F 51 C0
C3
link0%
01self-hosts
Source to
executable.
Nothing borrowed.
A one-time C seed produced the first binary. gcc has been out of the loop ever since — zc.zeph compiles itself to a byte-for-byte identical zc.exe.
$ zc --rt zc.zeph zc2.exe lex + parse ....... 10,012 lines type check ........ ok codegen x86-64 .... 214 KB assemble .......... in-house link PE ........... zc2.exe total ............. 0.12 s $ fc /b zc.exe zc2.exe FC: no differences encountered
1:1
byte-for-byte reproducible
0ms
frontend / 10k lines
0
DLL import — kernel32
02safe
Memory safe.
No borrow
checker.
A conservative mark-sweep GC reclaims memory, indexing is bounds-checked, every variable is initialized. No pointers, no malloc/free, no null. The whole class of memory bugs is simply unrepresentable.
// use-after-free ...... impossible // double-free ......... impossible // buffer overrun ...... bounds-checked // null deref .......... no null exists // uninitialized read .. every var init'd let v = xs.get(9).or(0) // absence, no panic
03fast
Faster than C.
We show the
checksums.
Same algorithm in all three languages, byte-identical output verified, then timed. Integer matmul, 768×768, best-of-7 on Zen5:
Zephyr42 ms
Rust −O70 ms
C −O272 ms
04link
One DLL.
Our own
linker.
No gcc, no ld, no external assembler in the pipeline. zc owns every stage — and a --rt build imports only kernel32.dll. Nothing else.
lexer → parser → types → codegen x86-64 → peephole → assembler → PE linker → app.exe // imports: kernel32.dll
05run
Build something
that builds
itself.
$ zc --rt hello.zeph hello.exe $ .\hello.exe Hello from Zephyr!