Learn more about a collection of modular and reusable compiler and toolchain technologies.

The primary sub-projects of LLVM are:
  1. The LLVM Core libraries provide a modern source- and target-independent optimizer, along with code generation support for many popular CPUs (as well as some less common ones!) These libraries are built around a well specified code representation known as the LLVM intermediate representation ("LLVM IR"). The LLVM Core libraries are well documented, and it is particularly easy to invent your own language (or port an existing compiler) to use LLVM as an optimizer and code generator.
  2. Clang is an "LLVM native" C/C++/Objective-C compiler, which aims to deliver amazingly fast compiles (e.g. about 3x faster than GCC when compiling Objective-C code in a debug configuration), extremely useful error and warning messages and to provide a platform for building great source level tools. The Clang Static Analyzer is a tool automatically finds bugs in your code, and is a great example of the sort of tool that can be built using the Clang frontend as a library to parse C/C++ code.
  3. dragonegg and llvm-gcc 4.2 integrate the LLVM optimizers and code generator with the GCC 4.5 (which is GPL3) and GCC 4.2 (which is GPL2) parsers, respectively. This allows LLVM to compile Ada, Fortran, and other languages supported by the GCC compiler frontends, and provides high-fidelity drop-in compatibility with their respective versions of GCC.
  4. The LLDB project builds on libraries provided by LLVM and Clang to provide a great native debugger. It uses the Clang ASTs and expression parser, LLVM JIT, LLVM disassembler, etc so that it provides an experience that "just works". It is also blazing fast and much more memory efficient than GDB at loading symbols.
  5. The libc++ and libc++ ABI projects provide a standard conformant and high-performance implementation of the C++ Standard Library, including full support for C++'0x.
  6. The compiler-rt project provides highly tuned implementations of the low-level code generator support routines like "__fixunsdfdi" and other calls generated when a target doesn't have a short sequence of native instructions to implement a core IR operation.
  7. The vmkit project is an implementation of the Java and .NET Virtual Machines that is built on LLVM technologies.
  8. The klee project implements a "symbolic virtual machine" which uses a theorem prover to try to evaluate all dynamic paths through a program, in an effort to find bugs and to prove properties of functions. A major feature of klee is that it can produce a testcase in the event that it detects a bug.
In addition to official subprojects of LLVM, there are a broad variety of other projects that use components of LLVM for various tasks. Through these external projects you can use LLVM to compile Ruby, Python, Haskell, Java, D, PHP, Pure, Lua, and a number of other languages. A major strength of LLVM is its versatility, flexibility, and reusability, which is why it is being used for such a wide variety of different tasks: everything from doing light-weight JIT compiles of embedded languages like Lua to compiling Fortran code for massive super computers.By TAATJENE

Comments

Post a Comment

Popular Posts