OMERO C++ language bindings =========================== Using the :zerocdoc:`Ice C++ language mapping ` from ZeroC_, OMERO provides native access to your data from C++ code. `CMake `_ is used for building the C++ bindings. **Binaries are not provided**, therefore it will be necessary for you to compile your own. Prerequisites ------------- * The OMERO source code * A C++ compiler * GCC is recommended for Linux and MacOS X * :program:`Visual Studio` or the :program:`Platform SDK` for Windows * The ZeroC :program:`Ice` libraries, headers and slice definitions * :program:`cmake` * Google Test (optional; needed to build the unit and integration tests) .. note:: Users of :program:`Visual Studio` with :program:`Ice` 3.6 will encounter this error while building OmeroCpp: ``LINK : fatal error LNK1189: library limit of 65535 objects exceeded`` and will be unable to build |OmeroCpp| for Windows as a result of a 16-bit limitation in the Windows PE-COFF executable format used for DLLs, even on 64-bit systems. Workarounds include: - using :program:`Ice` 3.5 (requires building :program:`Ice` against Python 2.7 with the same version of :program:`Visual Studio`) - it is hoped that :program:`Ice` 3.7 (when released) will resolve the problem since it generates far fewer symbols than 3.6 Restrictions ------------ If you are restricted to a specific version of GCC or Ice, you may need to obtain or build a compatible version of Ice or GCC, respectively. Preparing to build ------------------- Begin by following the instructions under :doc:`/developers/installation` to acquire the source code. Be **sure** that the git branch you are using matches the version of your server! The location of your Ice installation should be automatically detected if installed into a standard location. If this is not the case, set the location of your Ice installation using the :envvar:`ICE\_HOME` environment variable or the :option:`-DICE\_HOME` or :option:`-DIce_SLICE_DIR` :program:`cmake` options for your Ice installation (see below). Some possible locations for the |iceversion| version of Ice follow. Note these are just examples; you need to adjust them for the Ice installation path and version in use on your system. * Ice built from source and installed into :file:`/opt`: .. parsed-literal:: export ICE_HOME=/opt/Ice-|iceversion| * Ice installed on Linux using RPM packages: .. parsed-literal:: export ICE_HOME=/usr/share/Ice-|iceversion| * MacOS X with homebrew: .. parsed-literal:: export ICE_HOME=/usr/local/Cellar/ice/|iceversion| * Windows using :program:`Visual Studio`: .. parsed-literal:: set ICE_HOME=C:\\Program Files (x86)\\ZeroC\\Ice-|iceversion| .. note :: If the Ice headers and libraries are not automatically discovered, these will need to be specified using appropriate :program:`cmake` options (see below). Building the library -------------------- The shared library and examples are always built by default. The unit and integration tests are built if Google test (gtest) is detected. On Linux, Unix or MacOS X with :program:`make`:: export GTEST_ROOT=/path/to/gtest mkdir omero-build cd omero-build cmake [-Dtest=(TRUE|FALSE)] [cmake options] /path/to/openmicroscopy make For example:: cmake "-DCMAKE_CXX_FLAGS=$CMAKE_CXX_FLAGS" \ "-DCMAKE_EXE_LINKER_FLAGS=$CMAKE_LD_FLAGS" \ "-DCMAKE_MODULE_LINKER_FLAGS=$CMAKE_LD_FLAGS" \ "-DCMAKE_SHARED_LINKER_FLAGS=$CMAKE_LD_FLAGS" \ -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON /path/to/openmicroscopy make -j8 If you would like to build the C++ tests, run the above with the :envvar:`GTEST_ROOT` environment variable set. .. note:: When :program:`cmake` is run, it will run ``./build.py build-default`` in the openmicroscopy source tree to generate some of the C++ and Ice sources. If you have previously done a build by running ``./build.py``, this step will be skipped. However, if you have recently switched branches *without cleaning the source tree*, please run ``./build.py clean`` in the source tree to clean up all the generated files prior to running :program:`cmake`. If the build fails with errors such as :: /usr/include/Ice/ProxyHandle.h:176:13: error: ‘upCast’ was not declared in this scope, and no declarations were found by argument-dependent lookup at the point of instantiation this is caused by the Ice headers being buggy, and newer versions of GCC rejecting the invalid code. To compile in this situation, add ``-fpermissive`` to :envvar:`CXXFLAGS` to allow the invalid code to be accepted, but do note that this may also mask other problems so should not be used unless strictly needed. :program:`cmake` build configuration ------------------------------------ :program:`cmake` supports configuration of the build using many different environment variables and options; for a full list, see the `cmake reference documentation `_. The following environment variables are commonly needed: :envvar:`CMAKE_INCLUDE_PATH` Directories to be searched for include files, for example .. parsed-literal:: /opt/Ice-|iceversion|/include A ``:`` or ``;`` separator character is used to separate directories, depending on the platform. Note these are used only for feature tests, not for passing to the compiler when building, for which ``CMAKE_CXX_FLAGS`` is needed. :envvar:`CMAKE_LIBRARY_PATH` Directories to be searched for libraries, for example .. parsed-literal:: /opt/Ice-|iceversion|/lib Directories are separated by ``:`` or ``;`` as with :envvar:`CMAKE_INCLUDE_PATH`. Note these are used only for feature tests and finding libraries, not for passing to the linker when building, for which ``CMAKE_*_LINKER_FLAGS`` is needed. :envvar:`CXX` C++ compiler executable. Useful with `ccache `_. :envvar:`CXXFLAGS` C++ compiler flags. Use of ``CMAKE_CXX_FLAGS`` is preferred. :envvar:`ICE\_HOME` The location of the Ice installation. If this is not sufficient to discover the correct binary and library directories, they may otherwise be manually specified with the options below. Likewise for the :file:`include` and :file:`slice` directories. This may also be set as a :program:`cmake` cache variable (see below). :envvar:`VERBOSE` If set to `1`, show the actual build commands rather than the pretty "Compiling XYZ..." statements. In addition, :program:`cmake` options may be defined directly when running :program:`cmake`. Commonly needed options include: :option:`-DCMAKE_PREFIX_PATH` Search this location when searching for programs, headers and libraries. Use to search :file:`/usr/local` or :file:`/opt/Ice`, for example. More specific search locations may be specified using :option:`-DCMAKE_INCLUDE_PATH`, :option:`-DCMAKE_LIBRARY_PATH` and :option:`-DCMAKE_PROGRAM_PATH` separately, if required. :option:`-DCMAKE_INCLUDE_PATH` Search this location when searching for headers. Use to include :file:`/usr/local/include` or :file:`/opt/Ice/include`, for example. :option:`-DCMAKE_LIBRARY_PATH` Search this location when searching for libraries. Use to include :file:`/usr/local/lib` or :file:`/opt/Ice/lib`, for example. :option:`-DCMAKE_PROGRAM_PATH` Search this location when searching for programs. Use to include :file:`/usr/local/bin` or :file:`/opt/Ice/bin`, for example. :option:`-DCMAKE_CXX_FLAGS` C++ compiler flags. Use to set any additional linker flags desired. :option:`-DCMAKE_EXE_LINKER_FLAGS` Executable linker flags. Use to set any additional linker flags desired. :option:`-DCMAKE_MODULE_LINKER_FLAGS` Loadable module linker flags. Use to set any additional linker flags desired. :option:`-DCMAKE_SHARED_LINKER_FLAGS` Shared library linker flags. Use to set any additional linker flags desired. :option:`-DCMAKE_VERBOSE_MAKEFILE` Default to printing all commands executed by make. This may be overridden with the make ``VERBOSE`` variable. :option:`-DIce\_HOME` The location of the Ice installation. If this is not sufficient to discover the correct binary and library directories, they may otherwise be manually specified with the options below. Likewise for the :file:`include` and :file:`slice` directories. :option:`-DIce_SLICE2XXX_EXECUTABLE` Specific location of individual Ice ``slice2xxx`` programs, e.g. ``Ice_SLICE2CPP_EXECUTABLE`` for :program:`slice2cpp` or ``Ice_SLICE2JAVA_EXECUTABLE`` for :program:`slice2java`. These are typically found in ``${ICE_HOME}/bin`` or on the default :envvar:`PATH`. These will not normally require setting. :option:`-DIce_INCLUDE_DIR` Location of Ice headers. This is typically ``${ICE_HOME}/include`` or on the default include search path. This will not normally require setting. :option:`-DIce_SLICE_DIR` Location of Ice slice interface definitions. This is typically ``${ICE_HOME}/slice``. Use for installations where :option:`-DICE\_HOME` does not contain :file:`slice` or situations where you wish to build without setting :option:`-DICE\_HOME`. Note that when building using :program:`build.py`, rather than building directly with :program:`cmake`, the :envvar:`SLICEPATH` environment variable should be used instead (the :program:`ant` build can't use the :program:`cmake` variables since it only runs :program:`cmake` after a full build of the Java server). :option:`-DIce__LIBRARIES` Specific libraries for Ice component ````, where ```` is the uppercased name of the Ice component, e.g. ``ICE`` for the ``Ice`` component, ``ICEUTIL`` for the ``IceUtil`` component or ``GLACIER2`` for the ``Glacier2`` component. These libraries are typically found in ``${ICE_HOME}/lib`` or on the default library search path. These will not normally require setting. :option:`-DIce_DEBUG` Set to ON to print detailed diagnostics about the detected Ice installation. Use if there are any problems finding Ice. :program:`cmake` offers many additional options. Please refer to the `documentation `_ for further details, in particular to the `variables which change the behavior `_ of the build. :program:`Visual Studio` configuration -------------------------------------- .. warning:: OMERO.cpp will not currently build on Windows due to exceeding DLL symbol limits on this platform, leading to a failure when linking the DLL. It is hoped that this platform limitation can be worked around in a future OMERO release. :program:`cmake` has full support for :program:`Visual Studio`. Use the :program:`cmake` :option:`-G` option to set the generator for your Visual Studio version, with a ``Win64`` suffix for an x64 build. The correct Ice programs and libraries for your Ice installation should be automatically discovered. :: cmake -G "Visual Studio 11 Win64" [cmake options] /path/to/openmicroscopy This is for a 64-bit :program:`Visual Studio 2012` build. Modify appropriately for other versions and compilers. Running :: cmake --help will list the available generators for your platform (without the ``Win64`` suffix). Once :program:`cmake` has finished running, the generated project and solution files may be then opened in :program:`Visual Studio`, or built directly using the :program:`msbuild` command-line tool (make sure that the :program:`Visual Studio` command prompt matches the generator chosen) or by running:: cmake --build . As for the Unix build, above, it is also possible to build on Windows using :program:`build.py` or :program:`ant`, providing that you configure the generator appropriately using the correct :program:`cmake` options. However, this will not work for all generators reliably, and the Windows shell quoting makes passing nested quotes to ant quite tricky, so running :program:`cmake` by hand is recommended. .. note:: It may be necessary to specify ``/Zm1000`` as an additional compiler setting. Installing the library ---------------------- If using :program:`make`, run: :: make [DESTDIR=/path/to/staging/directory] install If using another build system, please invoke the equivalent install target for that system. Using the library ----------------- To use |OmeroCpp| it is necessary to point your compiler and linker at the mentioned directories above. A simple GNU :program:`make` :file:`Makefile` might look like this: .. literalinclude:: ../examples/omerocpp/Makefile :language: make :linenos: A trivial example: :file:`yourcode.cpp` --------------------------------------- A simple example might look something like the following: .. literalinclude:: ../examples/omerocpp/yourcode.cpp :language: c++ :linenos: This code does not do much. It creates a server session, loads a few services, and prints the user's name. For serious examples, see |OmeroClients|. Compiling and running your code ------------------------------- To compile and run :program:`yourcode`, download the two files above (:file:`Makefile` and :file:`yourcode.cpp`) and then in a shell: :: make OMERO_DIST=dist yourcode LD_LIBRARY_PATH=dist/lib ./yourcode --Ice.Config=dist/etc/ice.config where you have edited :file:`dist/etc/ice.config` to contain the values: :: omero.host=localhost omero.user=your_name omero.pass=your_password Alternatively, you can pass these on the command-line: :: LD_LIBRARY_PATH=dist/lib ./yourcode omero.host=localhost --omero.user=foo --omero.pass=bar .. note:: This example explains how to run on Linux only. For doing the same on MacOS X, change all instances of :envvar:`LD\_LIBRARY\_PATH` to :envvar:`DYLD\_LIBRARY\_PATH`. Further information ------------------- For the details behind writing, configuring, and executing a client, please see |OmeroClients|. .. seealso:: Ice_, |OmeroGrid|, |OmeroApi|, :doc:`/developers/build-system`, :ticket:`1596` which added 64-bit support