Cretonne is a low-level retargetable code generator. It translates a target-independent intermediate language into executable machine code.

This is a work in progress that is not yet functional.

Cretonne is designed to be a code generator for WebAssembly with these design goals:

No undefined behavior

Cretonne does not have a nasal demons clause, and it won't generate code with unexpected behavior if invariants are broken.

Portable semantics

As far as possible, Cretonne's input language has well-defined semantics that are the same on all target architectures. The semantics are usually the same as WebAssembly's.

Fast sandbox verification

Cretonne's input language has a safe subset for sandboxed code. No advanced analysis is required to verify memory safety as long as only the safe instructions are used. The safe instruction set is expressive enough to implement WebAssembly.

Scalable performance

Cretonne can be configured to generate code as quickly as possible, or it can generate very good code at the cost of slower compile times.

Predictable performance

When optimizing, Cretonne focuses on adapting the target-independent IL to the quirks of the target architecture. There are no advanced optimizations that sometimes work, sometimes fail.

Cretonne is using the Cargo package manager format. First, ensure you have installed rust 1.12.0 or above. Then, change the working directory to your clone of cretonne and run:

cargo build

This will create a target/debug directory where you can find the generated binary.

To build the optimized binary for release:

cargo build --release

You can then run tests with:

./test-all.sh

To build the Cretonne documentation, you need the Sphinx documentation generator:

$ pip install sphinx==1.3.5 sphinx-autobuild
$ cd cretonne/docs
$ make html
$ open _build/html/index.html

The specific Sphinx version is currently used by Read the Docs. Sphinx 1.4 has been released, but produces lots of warnings about four-column indices. We'll upgrade when Read the Docs does.