Chibil is a C compiler based on chibicc rewritten in C# and updated to target .NET IL (MSIL).

It is complete enough to run DOOM (PureDOOM).

Chibil takes C source files and generates COFF OBJ files. These OBJ files are by default binary-compatible with OBJ files produced by the MSVC compiler in /clr mode.

To produce assemblies, one can either:

• Use link.exe from Visual Studio; one can actually mix and match C++/CLI and chibil-produced object files, or
• Use chilink (-fuse-ld=chilink), a managed code linker from this repo

If you use link.exe, the output will be a mixed-mode assembly that only works on Windows.

If you use chilink, the output will be a pure IL assembly. Extra flags to chibil might be needed to generate output that chilink can convert to pure IL; this mode and experience around it is under development.

Note that even though the output is pure IL, the output is likely still platform dependent, especially if you compiled against any platform-dependent header files. At minimum you'll run into issues with pointer size (C compilation requires a pointer size that is known at compile time and not much can be done about it).

Line numbers and locals work as expected. You can step through the C code in a .NET debugger.

There isn't one.

There is a minimal stub of a C runtime library in the crt directory. This provides a runnable main that takes string[] of arguments and dispatches to the C-standard main with argc and argv. The produced assembly is converted to a COFF object file using the asm2obj utility and can be linked together with the C code to form something with a runnable main.

This is not complete yet. The code is generated into global namespace so if you want to consume the compiled code from elsewhere (i.e. don't intend to just run the EXE), you'll need to use reflection such as Module.GetMethod to find the methods and reflection-invoke them.

The tools/coffobjdumper.cs file contains a COFF OBJ dumper that dumps .NET OBJ files. It's a good complement for ILDASM (the desktop CLR ILDASM!) that can dump the .NET metadata from COFF OBJ files, but doesn't show method bodies, and dumpbin.exe that can dump various things from COFF objects, but not much in terms of .NET metadata.