LLVM D Compiler

LDC is a compiler for the D programming Language. It is based on the latest DMD frontend and uses LLVM 2.4 as backend. LLVM provides a fast and modern backend for high quality code generation. LDC is released under a BSD license with exceptions for the DMD frontend and code from GDC.

The development takes place mostly on x86-32 Linux and that is where LDC works best. Support for other platforms and architectures is under development, but we are still looking for people to help test and adjust LDC for those platforms!

LDC already compiles a lot of D code, but should still be considered beta quality. Take a look at the tickets to get a better impression on what still needs to be implemented.

We have two sets of tests living in the tests directory. The mini testsuite in mini/ and minicomplex/ contains a few tests that are supposed to compile or run and is mostly used when fixing a bug. There is also the larger DStress based test suite comparing LDC revisions among themselves and to DMD.

Project Status

The first release is near.
x86 Linux: Tango compiles and all its unittests pass. MiniD compiles. DWT still has issues.
Help is welcome for getting LDC to work on other platforms!
D2 support is highly experimental!

See the tickets for more details.

Communication

Feedback is much appreciated, you can contact us via IRC in the #ldc channel on FreeNode or the mailing list at ldc-dev@googlegroups.com.

The dsource forum is hardly ever looked at by the developers, please use the mailing list instead. If you've found a bug, feel free to report it directly.

D binding for LLVM

While not part of the LDC compiler, a llvm binding to LLVM for D can be found in the old SVN repository. The binding is a wrapper around the LLVM C interface with a few extensions. See the source/samples for more information.

Documentation

Documentation is still sparse, but there is a little on the versions and pragmas. There is also the beginnings of a hackers guide.

How To Compile

Dependencies:

cmake 2.6+
optional Hans Boehm GC 7.0 (direct download link) (for ldc itself, buggy and not recommended)
optional DSSS
optional GDC or DMD with Phobos (for building the test drivers)

Download, Compile and install LLVM 2.4

wget http://llvm.org/releases/2.4/llvm-2.4.tar.gz
tar -xvzf llvm-2.4.tar.gz
mv llvm-2.4 llvm-2.4-src
mkdir llvm-2.4-obj
cd llvm-2.4-obj
../llvm-2.4-src/configure --enable-optimized
make
su -c 'make install'
cd ..

Grab LDC from the Mercurial repository:

hg clone http://hg.dsource.org/projects/ldc ldc

Generate the LDC makefiles and

cd ldc
ccmake ./

enter D_VERSION "1" or "2", press 'c', press 'g'.

Compile ldc and include in your path

make
export PATH=`pwd`/bin:${PATH}

Fetch, patch and compile the tango runtime for dmd1:

svn co http://svn.dsource.org/projects/tango/trunk tango
make patch
make runtime

Fetch, patch and compile the druntime for dmd2:

svn co http://svn.dsource.org/projects/druntime/trunk druntime
make patch
make runtime

Help! Assertion `i < NumOperands && getOperand() out of range!' failed.

Your object.d has not been patched to work with LDC. Look at the instructions above regarding how to patch druntime or tango to work with LDC.

Using Tango

While LDC does use the Tango runtime per default, you still need to compile the Tango user library to build most applications. Otherwise you'll get linking errors when calling into tango code.

To build the Tango user library, go to the tango/lib directory and run sh build-tango.sh ldc. Copy the resulting libtango-user-ldc.a to LDC's lib directory and adjust your bin/ldc.conf to include -L-ltango-user-ldc.

Alternatively you can use Rebuild ...

Using Rebuild

Rebuild has some advantages to using a static Tango library (as described above). It compiles and links only to the modules you actually need, and changing the compiler options, for all the modules your application needs, is easy.

If you want to use DSSS or Rebuild with LDC, install the ldc-tango Rebuild profile from the root dir:

mkdir -p $HOME/.rebuild
ln -s `pwd`/ldc-tango $HOME/.rebuild

After you made sure that LDC is in PATH, you can use Rebuild from anywhere.

export PATH=$PATH:`pwd`/bin
rebuild -dc=ldc-tango test.d

Submitting Patches

Clone the Mercurial repository, make your changes, then use hg export and send the output to either lindquist or ChristianK:

hg export <revision> > blah-blah.patch

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