Compiling Orthanc

Under GNU/Linux

Under Microsoft Windows

See the build instructions for Windows inside the source package.

Under OS X

The mainline of Orthanc can compile under Apple OS X, with the XCode compiler, since June 24th, 2014. See the build instructions for Darwin inside the source package.

Performance warning

If performance is important to you, make sure to add the option -DCMAKE_BUILD_TYPE=Release when invoking cmake. Indeed, by default, run-time debug assertions are enabled, which can seriously impact performance, especially if your Orthanc server stores a lot of DICOM instances.

Please explain the build infrastructure

The build infrastructure of Orthanc is based upon CMake. The build scripts are designed to embed all the third-party dependencies directly inside the Orthanc executable. This is the meaning of the -DSTATIC_BUILD=ON option, as described in the INSTALL file of Orthanc.

Such a static linking is very desirable under Windows, since the Orthanc binaries do not depend on any external DLL, which results in a straightforward installation procedure (just download the Windows binaries and execute them), which eases the setup of the development machines (no external library is to be manually installed, everything is downloaded during the build configuration), and which avoids the DLL hell. As a downside, this makes our build infrastructure rather complex.

Static linking is not as desirable under GNU/Linux than under Windows. GNU/Linux prefers software that dynamically links against the system-wide libraries: This is explained by the fact that whenever a third-party dependency benefits from a bugfix, any software that is linked against it also immediately benefits from this fix. This also reduces the size of the binaries as well as the build time. Under GNU/Linux, it is thus recommended to use the -DSTATIC_BUILD=OFF option whenever possible.

When the dynamic build is used, some third-party dependencies may be unavailable or incompatible with Orthanc, depending on your GNU/Linux distribution. Some CMake options have thus been introduced to force the static linking against some individual third-party dependencies. Here are the most useful:

  • -DUSE_SYSTEM_DCMTK=OFF to statically link against DCMTK.
  • -DUSE_SYSTEM_JSONCPP=OFF to statically link against JsonCpp.

You will also have to set the -DALLOW_DOWNLOADS=ON to explicitely allow the CMake script to download the source code of any required dependency. The source code of all these dependencies is self-hosted on the Web server running our official homepage.

Please also note that the option -DSTANDALONE_BUILD=ON must be used whenever your plan to move the binaries or to install them on another computer. This option will embed all the external resource files (notably Orthanc Explorer) into the resulting executable. If this option is set to OFF, the resources will be read from the source directories.

Missing uuid-dev package

Orthanc might fail to compile, complaining about missing uuid-dev package.

This problem seems to occur when fist building Orthanc without the uuid-dev package installed, then installing uuid-dev, then rebuilding Orthanc. It seems that the build scripts do not update the cached variable about the presence of uuid-dev.

To solve this problem, as reported by Peter Somlo, it is necessary to entirely remove the build directory (e.g. with rm -rf Build) and start again the build from a fresh directory.