assembly

Miden assembly

This crate contains Miden assembler.

The purpose of the assembler is to compile Miden assembly source code into a Miden VM program (represented by Program struct). The program can then be executed on Miden VM processor.

Compiling assembly code

To compile Miden assembly source code into a program for Miden VM, you first need to instantiate the assembler, and then call its compile() method. This method takes the following arguments:

• source: &str - a reference to a string containing Miden assembly source code.

The compile() function returns Result<Program, AssemblyError> which will contain the compiled program if the compilation was successful, or if the source code contained errors, description of the first encountered error.

For example:

use miden_assembly::Assembler;

// instantiate a default assembler
let assembler = Assembler::default();

// compile a program which pushes values 3 and 5 onto the stack and adds them
let program = assembler.compile("begin push.3 push.5 add end").unwrap();

Assembler options

By default, the assembler is instantiated in the most minimal form. To extend the capabilities of the assembler, you can apply a chain of with_* methods to the default instance in a builder pattern. The set of currently available options is described below.

Libraries

To enable calls to procedures from external modules, the assembler must be supplied with libraries containing these modules. This can be done via with_library() or with_libraries() methods.

A library can be anything that implements the Library trait. We have implemented this trait for the Miden standard library. Thus, for example, to make Miden stdlib available to programs during compilation, the assembler can be instantiated as follows:

use miden_assembly::Assembler;
use miden_stdlib::StdLibrary;

// instantiate the assembler with access to Miden stdlib
let assembler = Assembler::default().with_library(&StdLibrary::default()).unwrap();

Programs compiled with this assembler can invoke any procedure from Miden stdlib. For example, something like this will be possible:

use.std::math::u64

begin
    push.1.0
    push.2.0
    exec.u64::checked_add
end

We also provide a concrete implementation of the Library trait called MaslLibrary. This implementation can be used to instantiate libraries from .masl files.

Program kernels

A program kernel defines a set of procedures which can be invoked via syscall instructions. Miden programs are always compiled against some kernel, and by default this kernel is empty (i.e., no syscall's are possible).

Instantiating the assembler with a non-empty kernel can be done like so:

use miden_assembly::Assembler;

// define a kernel with a single exported procedure
let kernel_source = "export.foo add end";

// instantiate the assembler with a kernel
let assembler = Assembler::default().with_kernel(kernel_source).unwrap();

Programs compiled with this assembler will be able to make calls to foo procedure by executing syscall.foo instruction.

Debug mode

The assembler can be instantiated in debug mode. Compiling a program with such an assembler retains source mappings between assembly instructions and VM operations. Thus, when such a program is executed using the execute_iter() function of the processor, is it possible to tell exactly which assembly instruction is being executed at a specific VM cycle.

Instantiating the assembler in debug mode can be done like so:

use miden_assembly::Assembler;

// instantiate the assembler in debug mode
let assembler = Assembler::default().with_debug_mode(true);

Instantiating assembler with multiple options

As mentioned previously, a builder pattern can be used to chain multiple with_* method together. For example, an assembler can be instantiated with all available options like so:

use miden_assembly::Assembler;
use miden_stdlib::StdLibrary;

// source code of the kernel module
let kernel_source = "export.foo add end";

// instantiate the assembler
let assembler = Assembler::default()
    .with_debug_mode(true)
    .with_library(&StdLibrary::default())
    .and_then(|a| a.with_kernel(kernel_source))
    .unwrap();

License

This project is MIT licensed.