Keywords: clamdoc

## Using the system LLVM

Some problems have been reported when compiling ClamAV's built-in LLVM with recent C++ compiler releases. These problems may be avoided by installing and using an external LLVM system library. To configure ClamAV to use LLVM that is installed as a system library instead of the built-in LLVM JIT, use following:

    	$ ./configure --with-system-llvm=/myllvm/bin/llvm-config
    	$ make
    	$ sudo make install

The argument to `--with-system-llvm` is optional, indicating the path name of the LLVM configuration utility (llvm-config). With no argument to `--with-system-llvm`, `./configure` will search for LLVM in /usr/local/ and then /usr.
Recommended versions of LLVM are 3.2, 3.3, 3.4, and 3.5. Some installations have reported problems using earlier LLVM versions. Versions of LLVM beyond 3.5 are not currently supported in ClamAV.