## 2 Installation

You need the following tools to build CIL:

- A Unix-like shell environment (with bash, perl, make, mv, cp, etc.). On Windows, you will need cygwin with those packages.
- An ocaml compiler. You will need OCaml release 3.08 or higher to build CIL. CIL has been tested on Linux and on Windows (where it can behave as either Microsoft Visual C or gcc). On Windows, you can build CIL both with the cygwin version of ocaml (preferred) and with the Win32 version of ocaml.
- An underlying C compiler, which can be either gcc or Microsoft Visual C.

1. Get the source code.
   - Official distribution (Recommended):
     1. Download the CIL distribution (latest version is `http://sourceforge.net/projects/cil/files/cil/cil-1.6.0.tar.gz`). See the Section 20 for recent changes to the CIL distribution.
     2. Unzip and untar the source distribution. This will create a directory called `cil` whose structure is explained below.
        `tar xvfz cil-1.6.0.tar.gz`
   - Git Repository:
     Alternately, you can download an up to the minute version of CIL from our Subversion repository at:

             git clone git://cil.git.sourceforge.net/gitroot/cil/cil

     There is also a Github mirror:

             git clone git://github.com/kerneis/cil.git

     However, the Git version may be less stable than the released version. See the Changes section of doc/cil.tex to see what’s changed since the last release. There may be changes that aren’t yet documented in the .tex file or this website.
2. Enter the `cil` directory and run the `configure` script and then GNU make to build the distribution. If you are on Windows, at least the `configure` step must be run from within `bash`.
   `cd cil`
   `./configure`
   `make`
   `make quicktest`
3. You should now find `cilly.asm.exe` in a subdirectory of `obj`. The name of the subdirectory is either `x86_WIN32` if you are using `cygwin` on Windows or `x86_LINUX` if you are using Linux (although you should be using instead the Perl wrapper `bin/cilly`). Note that we do not have an `install` make target and you should use Cil from the development directory.

The `configure` script tries to find appropriate defaults for your system. You can control its actions by passing the following arguments:

- `CC=foo` Specifies the path for the `gcc` executable. By default whichever version is in the PATH is used. If `CC` specifies the Microsoft `cl` compiler, then that compiler will be set as the default one. Otherwise, the `gcc` compiler will be the default.

CIL requires an underlying C compiler and preprocessor. CIL depends on the underlying compiler and machine for the sizes and alignment of types. The installation procedure for CIL queries the underlying compiler for architecture and compiler dependent configuration parameters, such as the size of a pointer or the particular alignment rules for structure fields. (This means, of course, that you should re-run `./configure` when you move CIL to another machine.)

We have tested CIL on the following compilers:

- On Windows, `cl` compiler version 12.00.8168 (MSVC 6), 13.00.9466 (MSVC .Net), and 13.10.3077 (MSVC .Net 2003). Run `cl` with no arguments to get the compiler version.
- On Windows, using `cygwin` and `gcc` version 2.95.3, 3.0, 3.2, 3.3, and 3.4.
- On Linux, using `gcc` version 2.95.3, 3.0, 3.2, 3.3, 4.0, and 4.1.

Others have successfully used CIL on x86 processors with Mac OS X, FreeBSD and OpenBSD; on amd64 processors with FreeBSD; on SPARC processors with Solaris; and on PowerPC processors with Mac OS X. If you make any changes to the build system in order to run CIL on your platform, please send us a patch.

### 2.1 Building CIL on Windows with Microsoft Visual C

Some users might want to build a standalone CIL executable on Windows (an executable that does not require cygwin.dll to run). You will need cygwin for the build process only. Here is how we do it

1. Start with a clean CIL directory
2. Start a command-line window setup with the environment variables for Microsoft Visual Studio. You can do this by choosing Programs/Microsoft Visual Studio/Tools/Command Prompt. Check that you can run `cl`.
3. Ensure that `ocamlc` refers to a Win32 version of ocaml. Run `ocamlc -v` and look at the path to the standard library. If you have several versions of ocaml, you must set the following variables:

             set OCAMLWIN=C:/Programs/ocaml-win

             set OCAMLLIB=%OCAMLWIN%/lib
             set PATH=%OCAMLWIN%/bin;%PATH%
             set INCLUDE=%INCLUDE%;%OCAMLWIN%/inc
             set LIB=%LIB%;%OCAMLWIN%/lib;obj/x86_WIN32

4. Run `bash -c "./configure CC=cl"`.
5. Run `bash -c "make WIN32=1 quickbuild"`
6. Run `bash -c "make WIN32=1 NATIVECAML=1 cilly`
7. Run `bash -c "make WIN32=1 doc`
8. Run `bash -c "make WIN32=1 bindistrib-nocheck`

The above steps do not build the CIL library, but just the executable. The last step will create a subdirectory `TEMP_cil-bindistrib` that contains everything that you need to run CIL on another machine. You will have to edit manually some of the files in the `bin` directory to replace `CILHOME`. The resulting CIL can be run with ActiveState Perl also.