Compiling in MacOS X

This page explains several methods to compile code engines using MacOS X.

Using XCode

Most development of NairnMPM and NairnFEA is done in MacOS X and thus compiling on MacOS X is easy. The preferred method is to use XCode (but first you must install Xcode, install command line tools, and get a new compiler). A complete XCode project is located at

nairn-mpm-fea/Common/Projects/NairnMPM.xcodeproj

This project is called NairnMPM, but it includes all MPM and FEA source code in two targets named NairnMPM and NairnFEA. Once xerces is installed, open the NairnMPM.xcodeproj to compile the code by:

1. Select the target to compile - either NairnMPM or NairnFEA
2. Choose build and they will compile and be saved in XCode's derived data folder.

If a linking error occurs, you might have conflicting architectures between the XCode settings and the xerces library you installed. To fix this problem edit both the project and target settings and under the "Architectures" section, set the "Architectures" option to match the architecture you used when installing xerces or recompile xerces if needed.

Compiling Xerces on MacOS X

Before you can compile and run the project, however, you will need an installed version of the xerces library and a copy of the xerces header files. These compiling instructions assume they are installed in the default locations for MacOS X or at:

/usr/local/lib/libxerces-c.dylib

for the library and at

/usr/local/include

for the header files. These can be changed if needed by editing the project and target settings. Since revision 274 of the nairn-mpm-fea project, this library must be xerces 3.0 or newer; prior to that revision, it had be xerces 2.8 or older. These libraries can be obtained by downloading the xerces source code from the Apache Software Foundation web site and then building and installing xerces with the following steps:

1. First install XCode and command line tools.
2. Open Terminal app and navigate to the xerces source folder expanded from the downloaded file.
3. Configure the code with the command:

   ./configure CFLAGS="-arch x86_64" CXXFLAGS="-arch x86_64"

   where the provided arch (or architecture) is the desired option for your machine. The main Mac options are i386 for 32 bit Intel processors, x86_64 for 64 bit Intel processors, ppc for 32 bit PowerPC chips, or ppc64 for 64 bit PowerPC64 chips. Although i386 will work on any Intel processor, you should use x86_64 if you have a 64 bit processor, because the code will run faster. To determine how many bits your Intel chip has, chose "About This Mac" from the Apple menu, click "More Info..." button, and look up the processor name in the hardware section. The "Intel Core Solo" and "Intel Core Duo" are 32 bit chips and most others are 64 bit chips.
4. When the configuration is done, use the following commands:

   cd src
   make
   sudo make install

   These commands make the library (but not the unneeded xerces examples). The final install command after make is done, installs both the library and the header files at the default locations listed above. It requires sudo for you to provide your administrator password needed to authenticate installation and the default location (which is /usr/local).
5. When working with nairn-mpm-fea on a new Mac, the xerces installation only needs to be done once. The only reason to repeat it is when a new xerces version is available and/or the project requires a new version for compatibility.

MacOS X Command Line Compiling

It also possible to compile on MacOS X using a command line approach (after installing XCode and command line tools and after installing xerces and its header files as explained above making sure they are in the specified default locations). You can compile NairnMPM using:

cd nairn-mpm-fea/NairnMPM/build
make SYSTEM=mac

and compile NairnFEA using:

cd nairn-mpm-fea/NairnFEA/build
make SYSTEM=mac

All source code will be compiled and the executables will be installed in nairn-mpm-fea/NairnMPM/input or nairn-mpm-fea/NairnFEA/input, respectively. You can use an additional make install command to copy each compiled executable to your ~/bin folder if desired.

If the command-line compile does not work, the most likely explanation is a problem with the xerces installation. You either have to install it as specified above or edit the makefile to recognize your custom installation. The process is documented in the makefile and involves editing the xercesSo and headersPath variables for your different settings.

You can pass additional parameters to the make command to alter the compilation process. See comments in the makefile for all the latest options.

Installing XCode

All compiling on Mac requires that you install Xcode (even if you do not plan to use it for anything else). You can get Xcode from the Mac App Store or from the Apple Developer site. It is a large install. Once installed, you then need to install command line tools.

Unfortunately, the compilers provided in Apple's "Command Line Tools" do not support OpenMP used to make these code engines parallel. The three solutions are to compile without OpenMP (and lose all advantages of multiprocessor execution), to install and use the clang-mp compiler, or to install and use an unsupported GCC compiler. This package used the GCC compiler for several years, but could not find a way to make it work in XCode 8 or newer. For the future, it appears using clang-mp works better. Various checkouts of the project may be setup for either GCC or clang-mp. It should be easy to convert any checkout to use the compiler you prefer by making a few changes in the XCode project build settings.

Whenever you update your MacOS or Xcode, you may need to repeat some installation steps before you can return to compiling the code engines.

The following sections have more details on installations needed for compiling the code engines.

Installing Command Line Tools

Apple used to install command line tools by default, but stopped doing that in MacOS Lion. You now have to manually install the tools before you can compile code. These steps should work:

1. After installing XCode on a recent MacOS, you can install command line tools by opening Terminal app and enter: xcode-select --install. If this step does not work, you can see MacPorts for possible new instructions. You can also get the command line tools from the Apple developer website and search for command line tools (being sure to get the correct tools for you current Xcode and MacOS versions). You may need to be signed up as an Apple developer for this method.
2. You may need to agree to XCode license by using Terminal app to enter: sudo xcodebuild -license
3. Most tools should now be available. You should be able to make and install the xerces.
4. To compile the code engines for parallel code, you will additionally need to install a compiler that works with OpenMP (none is provided in the command line tools).

With each new system, Apple seems to creating road blocks to keep you from using you computer for interesting programming. For now, by using a few tricks it is still possible to get around their road blocks. Hopefully these tricks will continue to work in the future.

One issue in the XCode project is that it might not find your xerces library, even if it is in the standard location. If it is not found, the library may be in red in the "External Frameworks and Libraries" folder (or may not). A potential solution is to delete the reference to the library and then add it back. The problem is that you cannot navigate to the /usr/local/lib folder anymore (another new Apple "feature"). Here is a trick to get there:

1. In the Finder, use the "Go to Folder..." menu command and enter "/usr/local".
2. After it opens, choose the "Add To Sidebar" menu command. This folder will now appear in all file selection boxes.
3. Go back to XCode and use command to add files for adding the xerces library.
4. Go through your new "local" folder and select the xerces library file in /usr/local/lib.

Compile Without OpenMP

To compile without OpenMP, simply comment out the line

#define USE_OPENMP

in the MPMPrefix.hpp and/or FEAPrefix.hppfile, change the compiler to an Apple-approved compiler, and remove an build settings specific to use of OpenMP. You should then be able to compile to get serial version of the code engines.

The preferred solution is to switch to a compiler that supports OpenMP as explained in the next two sections

Install Clang-mp

The first step is to install Xcode and command lines tools (as explained above).

Install GCC 4.8 or Newer

The first step is to install a new compiler. A good way is to install GCC 4.8 or newer is to use MacPorts (current recommendation is to install GCC 4.9, because I could not get GCC 4.8 to work in MacOS El Capitan or newer). Once MacPorts tool is installed, the installation of GCC is easy, as explained in this blog. In brief, all you need is to open the Terminal app and enter:

sudo port selfupdate
sudo port install gcc49

The first command above is only needed to make sure your MacPorts is up to date. The second step will install the compiler at

/opt/local/bin/g++-mp-4.9

If you want to remove an older version of GCC after updating, such as removing GCC 4.8, you should be able to use

sudo port uninstall --follow-dependents gcc48

Finally, the makefiles in the build folders currently assume the above path for GCC 4.9 when command-line compiling on a Mac. If needed, you can update the makefile for a differently compiler on a Mac or you can use the CC option to specify path any compiler, such as:

make SYSTEM=mac CC=/opt/local/bin/g++-mp-4.9

Using GCC 4.8 or Newer in XCode

Using an unsupported compiler in XCode requires a hack. Fortunately, a friend of this project (Hammd Mazhar) has provided a solution. The process is explained on this blog (for XCode 4.x) with an update for Xcode 6.x and newer (so far). Warning: Although the hack still allows one to compile in XCode 8.x, it no long appears possible to link the code using GCC. See below for a clunky way to work in XCode 8.x.

In brief, the goal is to install a custom plug in. The shortest approach is download a plug in and install it:

1. For GCC 4.8 or GCC 4.9 installed as explained above, download this GCC 4.8 XCode plug in or this GCC 4.9 XCode plug in. For GCC newer then 4.9, you might find a plug in in the repository xcode-gcc.
2. For XCode 6.x through 8.x (and probably 5.x), the plug in must be installed in the application at:

   /Applications/Xcode.app/Contents/Plugins/Xcode3Core.ideplugin/Contents\
   /SharedSupport/Developer/Library/Xcode/Plug-ins/
   

3. For Xcode 4.x it can alternatively be installed at

   /Library/Application Support/Developer/Shared/Xcode/Plug-ins/
   

4. In your XCode project under "Other Warning Flags" remove the -Wmost option (if needed).
5. You should now be able to select GCC 4.8 or GCC 4.9 from the compiler pop-up menu and compile code using that compiler.
6. Note that this approach fails in El Capitan with XCode 7.x and fails when trying to link to the xerces library installed in its default location. One way to compile in El Capitan with XCode 7.x is:
   • Install GCC 4.9
   • Go to /opt/local/lib/gcc49 and create a symbolic link to the xerces library using:

     ln -s /usr/local/lib/libxerces-c-3.1.dylib libxerces-c-3.1.dylib 
     

     Note that the symbolic link is to a versioned xerces file and not the standard libxerces-c.dylib because linking to this link did not work. Because the xerces version is hard coded into the name, you will need to update when xerces is changed or alter the "3.1" if using a different version now. Although it should be possible to set Library Search Paths instead of creating this link, I could not get that approach to work, while the link did work.

   • Make sure to select compiler GCC 4.9 in XCode
   • Add -fopenmp to "Other C++ Flags" to make sure it is compiled with OpenMP

The second approach is to build the plug in yourself (this approach can also be used to customize the plug ins downloaded above). The details (from Hammad's blog 1 and blog 2) are as follows (and for GCC 4.9 or newer, replace all uses of 4.8 with the desired version):

1. For XCode 4.x, copy a current compiler plug in into to a /Library level plug in folder:
   • Go to XCode's plug-ins folder, which is in the application package:

     cd /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents\
     /SharedSupport/Developer/Library/Xcode/Plug-ins
     

   • Create a copy of "GCC 4.2.xcplugin", put it in the Xcode plugin folder (create that folder if needed), and go to its contents:

     sudo mkdir -p "/Library/Application Support/Developer/Shared/Xcode/Plug-ins/"
     sudo cp -r "GCC 4.2.xcplugin" "/Library/Application Support/Developer/Shared\
     /Xcode/Plug-ins/GCC 4.8.xcplugin"
     cd "/Library/Application Support/Developer/Shared/Xcode/Plug-ins/GCC 4.8.xcplugin/Contents"
     

2. For XCode 5.x and newer you have to either download the plug in (see above) or copy the one mentioned in the previous step from a copy of XCode 4.x. Once copied, in must be installed in the new XCode app instead of the folder in the previous step. The correct folder is

   /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents\
   /SharedSupport/Developer/Library/Xcode/Plug-ins
   

   Once copied to that folder, navigate to the contents of the plug in:

   cd /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents\
   /SharedSupport/Developer/Library/Xcode/Plug-insGCC 4.8.xcplugin/Contents
   

3. Using Terminal app inside the plug in, convert the binary plist into text xml and then open for editing (done with vi here, but could use another tool):

   sudo plutil -convert xml1 Info.plist
   sudo vi Info.plist
   

4. Make the following changes:

   "com.apple.xcode.compilers.gcc.42" -> "com.apple.xcode.compilers.gcc.48"
   "GCC 4.2 Compiler Xcode Plug-in" -> "GCC 4.8 Compiler Xcode Plug-in"
   

5. Save and convert Info.plist back to binary:

   sudo plutil -convert binary1 Info.plist
   

6. In the "Resources" folder rename two files:

   cd Resources/
   sudo mv GCC\ 4.2.xcspec GCC\ 4.8.xcspec
   cd English.lproj/
   sudo mv GCC\ 4.2.strings GCC\ 4.8.strings
   

7. Open the "GCC 4.8.xcspec" for editing (e.g., using sudo vi) and make the changes:

   Identifier = "com.apple.compilers.gcc.4_8";
   Name = "GCC 4.8";
   Description = "GNU C/C++ Compiler 4.8";
   Version = "4.8";
   ExecPath = "gcc-mp-4.8";
   ShowInCompilerSelectionPopup = YES;
   IsNoLongerSupported = NO;
   

8. Down further in that file, make the following changes:

   under Name = "GCC_ENABLE_PASCAL_STRINGS"; set DefaultValue = NO;
   under Name = "GCC_CW_ASM_SYNTAX"; set DefaultValue = NO;
   

9. Make other customizations, if desired.
10. In your Xcode project under "Other Warning Flags" remove the -Wmost option (if needed).
11. You should now be able to select GCC 4.8 from the compiler pop-up menu and compile code using that compiler.

Possible Changes Needed After Updating MacOS or XCode

Unfortunately, Apple does not do a very good job of preserving your prior settings after a major upgrade and you will often need a complete reinstall of anything installed using MacPorts. Some things that might be needed with each MacOS upgrade are:

1. Get the latest version of XCode (from developer web site or app store).
2. Reinstall command line tools in Terminal app by entering xcode-select --install
3. Agree to Xcode license in Terminal app using sudo xcodebuild -license (and provide your admin password).
4. You may need to uninstall all installed MacPorts (which includes GCC compiler tools), reinstall MacPorts, and then reinstall all previously installed options. The process is explained here Migrating a MacPorts Installation.
5. To compile in XCode, you will usually need to reinstall the plug to allow use of GCC compiler, as explained in the next section. This reinstall is needed even if you had in installed in the previous version.

Using XCode 8.x

With the introduction of MacOS Sierra and XCode 8.x, it appears Apple has neglected to consider developers of code that does not use the MacOS GUI or code that may want to using a different compiler than shipped with XCode. The above hack can still compile the code, but the GCC linking phase to create the executable binary no longer works. The problematic step is that XCode insists on linking to an SDK library (even though this code does not use anything from the MacOS SDK) and that library appears in a not format that not recognized by GCC. Furthermore, i cannot find anyway to tell XCode to skip this link option.

One option is to use XCode in the following clunky work flow:

1. Install plug-in that extends XCode to use the GCC compiler.
2. Write code as before and build the project at any time to check code syntax. If all code is valid, this build will end with a single error that occurs in the linking phase.
3. Open Terminal app (or keep it open) and compile the code using a command line to get the executable binary.

The above method is workable (unless someone finds a workaround or an update of XCode fixes the issue). The other options are to switch to a different IDE on Mac or Windows or do text file editing and compile using a command line.

Using Eclipse IDE

Because the Eclipse IDE can run on multiple platforms, you can use it on Mac OS X for compiling as well. For details, see help on compiling using Eclipse IDE.