Overbrain

An overdesigned Brainf*ck interpreter, compiler and Just-In-Time (JIT) compiler/runtime.

How to Build

To build, you need a Linux machine with GNU make and GCC.

Just run make in the top level directory. This builds two binaries in the src/ directory: bf and bfc.

How to Install (Optional)

Running make install in the top level directory will install bf and bfc in /usr/local/bin/.

Alternatively, the binaries can be run directly from their original location or copied anywhere.

How to Run

This software runs on any Linux machine and does not have dependencies beyond the standard C/POSIX library.

Usage: (bf|bfc) [options] program

The build process builds two binaries: bf and bfc. These two binaries accept all the same command line arguments and behave the same except that, by default, bf runs the program as if the -jit command line argument was specified whereas bfc compiles the program as if the -compile argument was specified. For both binaries, this default can be overwritten by command line arguments.

Options to Run a Program

The input program is run when one of the following options is specified:

• -jit runs the program using the Just-In-Time (JIT) compiler. This is the default for bf.
• -tree runs the program using the tree interpreter.
• -slow runs the program using the "slow" interpreter, which is a a naive interpreter that interprets the program text directly.

The following optimization options apply to both the JIT compiler and the tree interpreter. These options are ignored if the slow interpreter is selected:

• Specifying the -O0 option disables optimizations while -O1, -O2 or -O3 enables them. -O1, -O2 and -O3 are synonyms. The default is -O3.
• The -no-check option disables bound checks. Using this option is not recommended because it makes the program unsafe and the performance gain is marginal.

Options to Compile a Program

The input program is compiled when the -compile options is specified. This is the default for bfc.

The-o option specifies the output file. If this option is omitted, the default behaviour is to output the compiled program to standard output.

The -backend options selects the compilation backend, which determines the format of the output file:

• -backend elf64 compiles the program to an ELF64 binary that targets a 64-bit x86 Linux system. This is the default.
• -backend nasm compiles the program to assembly code intended for the Netwide Assembler (NASM).
• -backend c compiles the program to C source code.

Optimization options:

• Specifying the -O0 option disables optimizations while -O1, -O2 or -O3 enables them. -O1, -O2 and -O3 are synonyms. The default is -O3.
• The -no-check option disables bound checks. Using this option is not recommended because it makes the program unsafe and the performance gain is marginal.