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, 3.5, and 3.6. Some installations have reported problems using earlier LLVM versions. Versions of LLVM beyond 3.6 are not currently supported in ClamAV.