The Concrete Programming Language

This book is a work in progress, much like the language itself, proceed with caution.

Some stuff may be outdated.

Getting Started

Here we will discuss:

  • Installing Concrete on Linux, macOS.
  • Writing a simple program.
  • Using concrete to create a project.

Installation

Currently Concrete is distrubted via source only, so you will have to compile it:

git clone https://github.com/lambdaclass/concrete.git
cd concrete
make build
cp ./target/release/concrete /usr/local/bin/

Internal Details

Here you can find several internal and implementation details of how Concrete is made.

The Concrete IR

Currently in Concrete, the AST is lowered first to a IR to help support multiple targets and ease the generation of code on the end of the compilation process.

This IR is based on the concept of basic blocks, where within each block there is a linear flow (i.e) there is no branching.

Each block has a terminator, which for example can return or jump to another block, this is what defines the control flow of the program.

The ProgramBody

The ProgramBody holds the whole program, with all the modules defined within.

All modules, functions, constants, struct types, types, etc have a defined DefId.

The ProgramBody stores all of these in a flat structure, i.e, functions defined in a submodule are available for lookup directly by their id.

The ModuleBody

Defines a module in concrete.

This structure holds the ids of the functions, structs, modules, etc defined within this module. This allows to resolve imports.

It also has a symbol table and a import table to aid during the construction of the IR.

The FnBody

Defines a function in concrete.

It holds the basic blocks and the locals used within.

The BasicBlock

It holds a array of statements and a terminator.

The statements have no branching.

The terminator defines where to branch, return from a function, a switch, etc.

The Statement

Currently there are 3 kinds of statements: assign, storage live, storage dead.

Only assign is used currently: it contains a place and a rvalue.

Place

This defines a place in memory, where you can load or store.

RValue

A value found in the right hand side of an assignment, for example the use of an operand or a binary operation with 2 operands, a reference to a place, etc.

Operand

A operand is a value, either from a place in memory or constant data.

Local

A local is a local variable within a function body, it is defined by a place and the type of local, such as temporary, argument or a return pointer.