bfc

A simple optimizing brainfuck compiler written in C

Olle Lögdahl, 25 December 2021

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bfc is a simple brainfuck compiler (or assembly generator), able to produce x86_64 assembly. The compiler may also call as to compile the assembly into a linkable object. Written as a one day project, it's purely for educational purposes.

The compiler also implements some (albeit very simple) optimizations using patterns ([-] can be optimized as a set 0 for example).

Building & Usage

The only requirements to build are a C99+ POSIX compliant compiler and GNU make. bfc can be built and installed by:

make build
sudo make install

Compiling some branfuck code is then done by:

echo "+[-->-[>>+>-----<<]<--<---]>-.>>>+.>>..+++[.>]<<<<.+++.------.<<-.>>>>+." > hello.b
bfc -o hello.o hello.b
ld -o hello hello.o

The assembly can be inspected by running:

bfc -gS -o hello.s hello.o

Help

bfc [-gShv] [-o file] file
  S        skips the assembler and only outputs the generated assembly.
  g        generates assembly with comments about the bf instructions.
  o file   the file to write the assembly/linkable object to.
  h        shows this.
  v        shows the version of the program.

Testing

A part of the challenge was also writing a testssuite in sh for testing the compiler and the generated binaries. These can be run with make test to output the following:

./check.sh out/bfc nocolor
rot13:  ok
t10:    ok
t11:    ok
t12:    ok
t1:     ok
t3:     ok
t4:     ok
t5:     ok
t6:     ok
t7:     ok
t8:     ok
t9:     ok
ran 14 tests with 79 scenarios.

Licensing

This project, and all code it contains, is licensed under the MIT License and can be read here.