araq/nlvm

llvm IR generator for Nim

Introduction

NLVM (the nim-level virtual machine?) is in its present incarnation an llvm (http://llvm.org) IR generator for the Nim language (http://nim-lang.org).

In some distant future, it would be nice if (in no particular order):

• it could compile itself
• it generated executables
• it implemented more core Nim features (bounds checking etc)
• it had fewer bugs than the reference nim compiler
• it had a nice automated test suite
• someone found it useful
• earth survived humans

When I started on this little project, I knew neither llvm-ir nor Nim. Therefore, I'd specially like to thank the friendly folks at the #nim channel on freenode that never seemed to tire of my nooby questions. Also, thanks to all tutorial writers out there, on llvm, programming and other topics for providing such fine sources of copy-pa... er, inspiration!

Questions, patches, improvement suggestions and reviews welcome. When you find bugs, feel free to fix them as well :)

Fork and enjoy!

Jacek Sieka (arnetheduck on gmail point com), 2016-01-19

Compile instructions

To do what I do, you will need:

• Linux
• A C/C++ compiler (ironically, I happen to use gcc most of the time)

Start with a clone:

cd $SRC
git clone https://github.com/arnetheduck/nlvm.git
cd nlvm && git submodule update --init

Compile llvm shared library:

cd $SRC
wget http://llvm.org/releases/3.6.1/llvm-3.6.1.src.tar.xz
tar xvf llvm-3.6.1.src.tar.xz
cd llvm-3.6.1.src
mkdir build
cd build
../configure --disable-optimized --enable-debug-runtime --enable-targets=x86_64 --enable-shared 
make

Compile nim:

cd $SRC/nlvm/Nim
./bootstrap.sh

Compile nlvm:

cd $SRC/nlvm/nlvm
../Nim/bin/nim c nlvm

Run nlvm:

cd $SRC/nlvm/nlvm
LD_LIBRARY_PATH=$SRC/llvm-3.6.1.src/build/Debug+Asserts/lib ./nlvm c xxx.nim

Optimize with llvm (assuming llvm is in your $PATH):

opt -O3 nimcache/xxx.bc | llvm-dis

Compile with llvm (assuming llvm is in your $PATH):

llc xxx.bc
as xxx.s -o xxx.o
ld xxx.o -o xxx

Random notes

• I have no hopes of keeping up with upstream, so I've pinned it at a particular commit with the submodule - patches welcome to update to new upstream versions