= Preparing the Compilation =

Here we only describe the configuration procedure on UNIX-like systems (including Linux, Cygwin, and MSys), where the user can run the {{{configure}}} shell script.  If you are using the MS Developer Studio, you are referred to the [http://projects.coin-or.org/MSDevStudio MSDevStudio project page].

If you have problems, have a look at the [wiki:user-troubleshooting troubleshooting page.]

== Running the {{{configure}}} script ==

Assume that you have dowloaded the package {{{Pkg}}} 
in the directory {{{Coin-Pkg}}}. (If you got the code via a tarball, this directory might have a name like {{{Pgk-x.y.z}}}, where {{{x.y.z}}} is the point release number.)

Before you can compile the source code using {{{make}}}, the Makefiles have to be created, so that they contain the correct compiler names and options, as well as other system dependent information.  To this purpose, the {{{configure}}} shell scripts in the package's base directory (e.g., {{{Coin-Clp}}}) and in the projects' main directories (such as {{{Coin-Clp/Clp}}}) perform a number of tests and create the final Makefiles.  In addition, a {{{configure}}} script usually creates a header file (such as {{{Coin-Clp/Clp/inc/config_clp.h}}}) for the individual project, which contains {{{#define}}}s to help the source code to adapt to different platforms.

You can run the configuration scipts in the directories where the source files are.  However, we recommend to perform a "VPATH configuration" (see also below), which compiles the code in a separate directory tree:

First you create a new directory for the compiled code, change into this directory and then run the configuration script '''from the base directory''' in it.  The new directory can be anywhere; the following instruction assume that you are in the package's base directory ({{{Coin-Pkg}}}):
{{{
mkdir build
cd build
../configure
}}}

'''Note:''' You must run the base directory {{{configure}}} script, not one in a project subdirectory (such as {{{Coin-Clp/Clp}}}); the latter doesn't work.

This picks default settings for compilers and compiler options.  You can change some aspects of the configuration by providing arguments to the configuration script, as described below.

If the configuration is successful, the {{{configure}}} script usually prints a message indicating this.  '''If the configuration fails''', the output on the screen, or the more detailed output in one of the {{{config.log}}} files might help to find the cause - see the [wiki:user-troubleshooting Troubleshooting page].  If you are not able to fix the problem and want to contact the maintainers, you should submit a bug ticket at the corresponding Trac page and attach the {{{config.log}}} file that has the detailed error message in it.

'''Note:'''  If you rerun {{{configure}}} after a successful configuration run, you should do a '''make distclean''' if you changed the options for {{{configure}}}; see also the {{{make}}} target description at the [wiki:user-compile Compiling and installing the package] page.

== Giving Options to the {{{configure}}} Script ==

There are '''two types of arguments''' that can be given to the {{{configure}}} script.  The first set of arguments have the form of '''regular command line options''', such as {{{--enable-debug}}} or {{{-C}}}.  The second set of options works through '''variables''', and those can be provided either on the command line, or can be set as environment variables.

An alternative to providing configuration options through the command line is the {{{config.site}}} file, see below.

For most COIN packages, several configuration scripts are run recursively.  You need to '''specify the options for all subprojects''' (e.g., {{{Clp}}} and {{{CoinUtils}}}) when you run the base {{{configure}}} script, since they are given to the sub{{{configure}}} scripts.

You can see a '''list of all available options''' by running

{{{
./configure --help=recursive
}}}

=== Command Line Arguments for {{{configure}}} ===

The command line arguments are given to {{{configure}}} simply as additional arguments for to the command line.  Some common arguments are described here, but '''there might be additional options that you can find on the home pages for the individual COIN projects'''.

 * '''-C''': Makes {{{configure}}} '''use a cache file''' to speed up the tests when they been performed earlier; remember that a number of {{{configure}}} scripts are run recursively.  However, it is a good idea to '''delete the config.cache file before every command line rerun of configure''', so that changes in your local setup (such as added source code or changes in options) are correctly considered.

 * '''--prefix''': By default, the binaries and header files are installed (by {{{make install}}}) into {{{bin}}}, {{{lib}}}, and {{{include}}} directories of where the main configuration scripts was run.  If you prefer to have {{{make install}}} '''install in a different location''' (such as {{{$HOME}}}), you need to use this option, e.g., with {{{--prefix=$HOME}}}.

 * '''--enable-debug''': This causes {{{configure}}} to select the '''debug compiler options'''.  It also defines the preprocessor macro {{{COIN_DEBUG}}}, which in some source code is use to '''activate additional (time-consuming) consistency tests'''.

 * '''--enable-static''': By default, the COIN libraries are compiled as shared libraries or DLLs, at least on platforms that support this.  If you want to also have '''static libraries to be generated as well''', you need to specify this option.

 * '''--disable-shared''': If you want '''only static libraries''' to be compiled and no shared objects or DLLs, you should specify this option.

 * '''--enable-gnu-packages''': Some of the COIN projects can make use of GNU packages (such as zlib, bzlib, or readline).  Since those are usually provided under the GPL license, which has rather strong conditions, the configuration scripts do not check for the availability of those packages by default.  If you want to '''compile the COIN code so that it uses GNU packages''', you need to provide this option. (Usually it will be necessary to add to CPPFLAGS the include-path and to LDFLAGS the path to the library, so that the package's header and library are found).

 * Further options of the form '''--enable-...''' and '''with-...''' might be understood by the configuration scripts '''for specific COIN projects'''.  For example, if you want to tell the Open Solver Interface (OSI) that you want to compile the Cplex solver interface, you need to specify the {{{--with-cplex-lib}}} and {{{--with-cplex-incdir}}} options with the appropriate values.  (If such a value consists of more than one word, you need to enclose it in quotation marks.) For example:

    {{{--with-cplex-lib}}}="-L/usr/ilog/cplex90/lib/static_pic -lcplex" 

 assuming that the cplex library (usually named libcplex.a)
is located in /usr/ilog/cplex90/lib/static_pic.
Note that, on some systems, the threading library must be 
added for cplex to work. In this case, the string is:

    {{{--with-cplex-lib}}}="-L/usr/ilog/cplex90/lib/static_pic -lcplex -lpthread" 

 For the include string:

    {{{--with-cplex-incdir}}}="/usr/ilog/cplex90/include/ilcplex"

 assuming that the header file cplex.h is located in the directory
/usr/ilog/cplex90/include/ilcplex.


 A typical call for the configuration script would then look like

    {{{
./configure --with-cplex-lib="-L/usr/ilog/cplex90/lib/static_pic -lcplex" \
            --with-cplex-incdir="/usr/ilog/cplex90/include/ilcplex" \
            --enable-static -C
}}}

=== Variable Arguments for {{{configure}}} ===

Other options, usually related to compilation configuration (such as compiler names and options) can be set as variables.  The values for those variables can be either '''provided as environment variables''' (e.g., set in your shell startup script), '''or on the command line'''.  Values set on the command line overwrite values set in the environment.  If you want to set the value of a variable (such as {{{CXX}}}) in the comamnd line for {{{configure}}}, you simply list the variable, followed ''immediately'' by an {{{=}}} and the value, possibly enclosed in quotation marks (such as CXX="cl").

Commonly used variable arguments are

 * '''CC''':  Name of the '''C compiler'''.  If this is not given, the {{{configure}}} script tries a list of compiler names.  You only need to specify this if you are not happy with the default selection.  If you want to compile the code in a non-default bit mode (say, 64bit on AIX), you should specify the corresponding flag here (e.g., {{{CC='xlc -q64'}}}), and not in {{{CFLAGS}}}.

 * '''CFLAGS''':  '''C compiler flags'''.  If this is not given, the {{{configure}}} script chooses a default set of compiler flags, depending on the compiler, operating system, and whether the {{{--enable-debug}}} flag is given.

 * '''CXX''':  Name of the '''C++ compiler'''.  If this is not given, the {{{configure}}} script tries a list of compiler names.  You only need to specify this if you are not happy with the default selection.  If you want to compile the code in a non-default bit mode (say, 64bit on AIX), you should specify the corresponding flag here (e.g., {{{CXX='xlC -q64'}}}), and not in {{{CXXFLAGS}}}.  This only applies to packages that require the C++ compiler.

 * '''CXXFLAGS''':  '''C++ compiler flags'''.  If this is not given, the {{{configure}}} script chooses a default set of compiler flags, depending on the compiler, operating system, and whether the {{{--enable-debug}}} flag is given.  This only applies to packages that require the C++ compiler.

 * '''F77''':  Name of the '''Fortran compiler'''.  If this is not given, the {{{configure}}} script tries a list of compiler names.  You only need to specify this if you are not happy with the default selection.  If you want to compile the code in a non-default bit mode (say, 64bit on AIX), you should specify the corresponding flag here (e.g., {{{F77='xlf -q64'}}}), and not in {{{FFLAGS}}}.  This only applies to packages that require the Fortran compiler.

 * '''FFLAGS''':  '''Fortran compiler flags'''.  If this is not given, the {{{configure}}} script chooses a default set of compiler flags, depending on the compiler, operating system, and whether the {{{--enable-debug}}} flag is given.  This only applies to packages that require the Fortran compiler.

 * '''ADDDEFS''':  If you want to have the C and C++ compile use '''additional -D preprocessor macro defintions''', you should list them in this variable (e.g., {{{ADDDEFS="-DPARANOIA"}}}).

 * '''AR''':  '''Program for handling archives'''.  The default selection usually works fine.  Only on some systems (such as AIX), it is necessary to specify additional flags when compiling in 64bit mode (e.g., {{{AR="ar -X64"}}}).

 * '''NM''':  '''Program for listing symbols''' in object files.  The default selection usually works fine.  Only on some systems (such as AIX), it is necessary to specify additional flags when compiling in 64bit mode (e.g., {{{NM="nm -X64"}}}).

 * '''COIN_SKIP_PROJECTS''':  This allows to '''specify a list of COIN subprojects that should not be compiled'''.  For example, if you obtained the Osi package, but do not want to compile the {{{DyLP}}} and {{{Vol}}} subproject, you would specify '''COIN_SKIP_PROJECTS="DyLP Vol"'''.  This will skip the compilations of the DyLP and Vol libraries, and it will also not create the !OsiDylp and !OsiVol libraries.

A complete invokation of the configure script could look like:

{{{
./configure CXX="xlC -q64" CC="xlc -q64" F77="xlf -q64" AR="ar -X64" \
            NM="nm -X64" --enable-gnu-packages -C
}}}

Invoking the configuration script in cygwin when using the Microsoft Visual Studio Version 6 compiler typically will look like:

{{{
./configure -C CXX='cl -GX -GR'
}}}

== Specifying Options in a {{{config.site}}} File ==

Setting all configuration arguments in the command line for {{{configure}}} can be somewhat inconvenient.  You can alternatively '''specify your choices in a file''' that is automatically read when {{{configure}}} is run.

The name of this file is {{{config.site}}}.  The {{{configure}}} script looks for it in the '''share subdirectory of the installation directory''' (i.e., what you speficy with the {{{--prefix}}} argument, or by default in the {{{share}}} subdirectory of where you run {{{configure}}}).  You can specify a different location and name by setting the environment variable '''CONFIG_SITE''' to the full path to your {{{config.site}}} file, including the file name itself.

The {{{config.site}}} file is a '''shell script''' (for {{{bin/sh}}}) and needs to follow the shell's syntax.  It is used to set values of shell variables that are internally used by the {{{configure}}} script.  In case of '''variable arguments''' (such as {{{CC}}}), the name that should be used in {{{config.site}}} is identical to the name that could be specified in the command line.  For {{{--enable-...}}}-type arguments, the corresponding {{{config.site}}} shell variable is '''enable_...''' with the dashes replaced by underscore; to specify that the features is to be used, set this variable to {{{yes}}}, and to disable it, set it to {{{no}}}.  For {{{--with-...}}}-type arguments use the variable name '''with_...''', again with dashes replaced by underscores, and set it to the chosen value.  If no value is required, set it to {{{yes}}}, and to mimic a {{{--without...}}} option, set the corresponding {{{with_...}}} variable to {{{no}}}.

''Note: Since the {{{config.site}}} file is a shell script, you must not have any whitespace before and after the "{{{=}}}" symbol in a variable assignment!''

An '''example [https://projects.coin-or.org/BuildTools/browser/stable/0.5/share/config.site?format=raw config.site] file''' can be found in the {{{BuildTools/share}}} directory.

== Performing a VPATH Compilation ==

It is possible to '''compile the code in a different place than where the source code is''' (using the make VPATH feature).  This can, for example, be handy, if you want to have several compiled versions around (e.g., for different operating systems when you are working on a shared files system, or a production and debug version).

To do a VPATH compilation, you simply run the {{{configure}}} script in the directory where you want to have the compiled files.  E.g., if the base directory of the COIN packages is in {{{$HOME/Coin-Pkg}}} and you want to compile the code in {{{$HOME/Obj/debug/Coin-Pkg}}}, you type

{{{
cd $HOME/Obj/debug/Coin-Pkg
$HOME/Coin-Pkg/configure --enable-debug -C
}}}

(Of course, you use those options for {{{configure}}} that you want to use, not necessarily the above ones.)  After you run {{{configure}}}, you will find the same directory structure under {{{$HOME/Obj/debug/Coin-Pkg}}} as in {{{$HOME/Coin-Pkg}}} (at least those directories that have source code in {{{$HOME/Coin-Pkg}}}), together with the Makefiles.  To compile the code, you how enter the {{{make}}} commands in {{{$HOME/Obj/debug/Coin-Pkg}}}.  Note, that if you install the code and didn't specify a specific installation location with the {{{--prefix}}} flag, the installed files will go into {{{bin}}}, {{{lib}}}, and {{{include}}} subdirectories of {{{$HOME/Obj/debug/Coin-Pkg}}}.

'''Note:''' A VPATH compilation is not possible, if you ran {{{configure}}} already in the source code directory ({{{$HOME/Coin-Pkg}}} in the example above).  You would need to do a {{{make distclean}}} in the source code directory first.