A good starting point is to read and look through the papers and presentations about Sulong. The paper Sulong - Execution of LLVM-Based Languages on the JVM provides a minimal description of Sulong and describes its main goals.
To understand more about Truffle, on which Sulong is implemented, is to read the papers Self-optimizing AST interpreters and One VM to rule them all. A heavily documented Truffle language sample implementation is SimpleLanguage.
Sulong is the romanization of the Chinese term "速龙" (Velocisaurus). The first character translates as fast, rapid or quick, while the second character means dragon. A literal translation of the name giving Chinese term is thus "fast dragon". The name relates to the LLVM logo which is a dragon (more specifically a wyvern), and is also in line with the LLVM Dragonegg project.
Truffle is a language implementation framework written in Java. It allows language designers to implement a (guest) language as an Abstract Syntax Tree (AST) interpreter. Additionally, Truffle provides many language independent services to the host language such as a profiler, a debugger, and language interoperability. If a Truffle AST is executed often, it will be dynamically compiled by the GraalVM compiler. The GraalVM compiler can exploit its knowledge about the Truffle framework and produce efficient machine code.
LLVM is an umbrella project for a modular and reusable compiler
infrastructure written in C++. It includes a compiler frontend clang
for compiling C, C++, Objective C and Objective C++ to LLVM bitcode IR,
other tools such as the optimizer opt, assembler, linker, and back-ends
that operate on the LLVM bitcode to finally produce machine code. LLVM
envisions that transformations and analyses can be applied during
compile-time, link-time, runtime, and offline.
To get a command line command you can use the -v mx option. For
example, mx -v lli test.bc prints the command line mx uses to run
the file test.bc with Sulong.
You can clean your workspace with mx clean. If you only want to clean
Java or native projects you can use mx clean with the options
--no-native or --no-java.
In order to work with Eclipse, use mx eclipseinit to generate the
Eclipse project files. Then import all projects into your workspace
(File>Import>General, then select "Existing Projects into Workspace",
then browse to your repository checkout).
In addition to the Sulong projects, you also have to import its
dependencies Truffle (from workspace/graal/truffle) and the GraalVM
SDK (from workspace/graal/sdk).
For generating Netbeans project files, use mx netbeansinit. Then
open the projects you are interested in (File>Open Project).
IntelliJ project files can be generated with mx intellijinit.
To debug the execution of a bitcode file in an IDE, first start an mx
command with the -d flag, e.g.:
$ mx -d lli test.ll
Listening for transport dt_socket at address: 8000
Then you can attach your IDE to the running Java process on port 8000.
See also Debugging the GraalVM Runtime.