5.2. Building the Connext DDS Micro Source

5.2.1. Introduction

RTI Connext DDS Micro has been engineered for reasonable portability to common platforms and environments, such as Darwin, iOS, Linux, and Windows. This document explains how to build the Connext DDS Micro source-code. The focus of this document is building Connext DDS Micro for an architecture supported by RTI (please refer to RTI Connext DDS Micro Supported Platforms for more information). Please refer to Porting RTI Connext DDS Micro for documentation on how to port Connext DDS Micro to an unsupported architecture.

This manual is written for developers and engineers with a background in software development. It is recommended to read the document in order, as one section may refer to or assume knowledge about concepts described in a preceding section.

5.2.2. The Host and Target Environment

The following terminology is used to refer to the environment in which Connext DDS Micro is built and run:

• The host is the machine that runs the software to compile and link Connext DDS Micro.

• The target is the machine that runs Connext DDS Micro.

• In many cases Connext DDS Micro is built and run on the same machine. This is referred to as a self-hosted environment.

The environment is the collection of tools, OS, compiler, linker, hardware etc. needed to build and run applications.

The word must describes a requirement that must be met. Failure to meet a must requirement may result in failure to compile, use or run Connext DDS Micro.

The word should describes a requirement that is strongly recommended to be met. A failure to meet a should recommendation may require modification to how Connext DDS Micro is built, used, or run.

The word may is used to describe an optional feature.

5.2.2.1. The Host Environment

RTI Connext DDS Micro has been designed to be easy to build and to require few tools on the host.

The host machine must:

• support long filenames (8.3 will not work). Connext DDS Micro does not require a case sensitive file-system.

• have the necessary compiler, linkers, and build-tools installed.

The host machine should:

• have CMake (www.cmake.org) installed. Note that it is not required to use CMake to build Connext DDS Micro, and in some cases it may also not be recommended. As a rule of thumb, if RTI Connext DDS Micro can be built from the command-line, CMake is recommended.

• be able to run bash shell scripts (Unix type systems) or BAT scripts (Windows machines).

Typical examples of host machines are:

• a Linux PC with the GNU tools installed (make, gcc, g++, etc).

• a Mac computer with Xcode and the command-line tools installed.

• a Windows computer with Microsoft Visual Studio Express edition.

• a Linux, Mac or Windows computer with an embedded development tool-suite.

5.2.2.2. The Target Environment

Connext DDS Micro has been designed to run on a wide variety of targets. For example, Connext DDS Micro can be ported to run with no OS, an RTOS, GNU libc or a non-standard C library etc. This section only lists the minimum requirements. Please refer to Porting RTI Connext DDS Micro for how to port Connext DDS Micro.

The target machine must:

• support 8, 16, 32 and 64-bit signed and unsigned integers. Note that a 16-bit CPU (or even 8-bit) is supported as long as the listed types are supported.

  Connext DDS Micro supports 64-bit CPUs and uses native 64-bit arithmetic internally.

The target compiler should:

• have a C compiler that is C99 compliant. Note that many non-standard compilers work, but may require additional configuration.

• have a C++ compiler that is C++98 compliant (Not required for only Connext DDS Micro Cert since C++ is not supported).

The remainder of this manual assumes that the target environment is one supported by RTI:

• POSIX (Linux, Darwin, QNX®, VOS, iOS, Android).

• VxWorks 6.9 or later.

• Windows.

• QNX.

5.2.3. Overview of the Connext DDS Micro Source

The source-code is exactly the same as developed and tested by RTI. No filtering or modifications are performed.

RTIMEHOME--+-- CMakeLists.txt
           |
           +-- build -- cmake --+-- Debug --+-- <ARCH> -- <project-files>
           |                    |
           |                    |
           |                    +-- Release --+-- <ARCH> -- <project-files>
           +-- doc --
           |
           +-- example
           |
           +-- include
           |
           +-- lib +-- <ARCH> -- <libraries>
           |
           +-- resource --+-- cmake
           |              |
           |              +-- scripts
           |
           +-- rtiddsgen
           |
           +-- rtiddsmag
           |
           +-- src

In this document, RTIMEHOME refers to the root directory where the rti_connext_dds_micro is extracted and installed.

5.2.3.1. Directory Structure

The recommended directory structure is described below and should be used (1) because:

• the rtime-make script that is part of the installation expects this directory structure to run CMake .

• this directory structure supports multiple architectures.

NOTE 1: This applies to builds using CMake. To build in a custom environment, please refer to Custom Build Environments. Please note that Connext DDS Micro Cert can only be built with cmake.

CMakeLists.txt is the main input file to CMake and is used to generate build files.

The RTIMEHOME/include directory contains the public header files. By default it is identical to RTIMEHOME/include. However, custom ports will typically add files to this directory.

The RTIMEHOME/lib directory is empty by default. All libraries successfully built with the CMake generated build-files, regardless of which generator was used, will be copied to the RTIMEHOME/lib directory.

The RTIMEHOME/src directory contains the Connext DDS Micro source files. RTI does not support modifications to these files unless explicitly stated in the porting guide. A custom port will typically add specific files to this directory.

The RTIMEHOME/build directory is empty by default. CMake generates one set of build-files for each configuration. A build configuration can be an architecture, Connext DDS Micro options, language selection, etc. This directory will contain CMake generated build-files per architecture per configuration. By convention the Debug directory is used to generate build-files for debug libraries and the Release directory is used for release libraries.

The following naming conventions are used regardless of the build-tool:

• Static libraries have a z suffix.

• Shared libraries do not have an additional suffix.

• Debug libraries have a d suffix.

• Release libraries do not have an additional suffix.

The following libraries are built:

• rti_me - the core library, including the DDS C API

• rti_me_discdpde - the Dynamic Participant Dynamic Endpoint plugin

• rti_me_discdpse - the Dynamic Participant Static Endpoint plugin

• rti_me_rhsm - the Reader History plugin

• rti_me_whsm - the Writer History plugin

• rti_me_cpp - the C++ API

Note: The names above are the Connext DDS Micro library names. Depending on the target architecture, the library name is prefixed with lib and the library suffix also varies between target architectures, such as .so, .dylib, etc.

For example:

• rti_mezd indicates a static debug library

• rti_me indicates a dynamically linked release library

5.2.4. Compiling Connext DDS Micro

This section describes in detail how to compile Connext DDS Micro using CMake. It starts with an example that uses the included scripts followed by a section showing how to build manually.

CMake, available from www.cmake.org, is the preferred tool to build Connext DDS Micro because it simplifies configuring the Connext DDS Micro build options and generates build files for a variety of environments. Note that CMake itself does not compile anything. CMake is used to generate build files for a number of environments, such as make, Eclipse® CDT, Xcode® and Visual Studio. Once the build-files have been generated, any of the tools mentioned can be used to build Connext DDS Micro. This system makes it easier to support building Connext DDS Micro in different build environments. CMake is easy to install with pre-built binaries for common environments and has no dependencies on external tools.

NOTE: It is not required to use CMake. Please refer to Custom Build Environments for other ways to build Connext DDS Micro.

5.2.4.1. Building Connext DDS Micro with rtime-make

The Connext DDS Micro source bundle includes a bash (UNIX) and BAT (Windows) script to simplify the invocation of CMake. These scripts are a convenient way to invoke CMake with the correct options.

On UNIX-based systems:

RTIMEHOME/resource/scripts/rtime-make --config Debug --target self \
              --name i86Linux2.6gcc4.4.5 -G "Unix Makefiles" --build

On Windows systems:

RTIMEHOME\resource\scripts\rtime-make --config Debug --target self \
           --name i86Win32VS2010 -G "Visual Studio 10 2010" --build

Explanation of arguments:

• --config Debug : Create Debug build.

• --target <target> : The target for the sources to be built. “self” indicates that the host machine is the target and Connext DDS Micro will be built with the options that CMake automatically determines for the local compiler. Please refer to Cross-Compiling Connext DDS Micro for information on specifying the target architecture to build for.

• --name <name> : The name of the build, shall be a descriptive name following the recommendation on naming described in section Preparing for a Build. If --name is not specified, the value for --target will be used as the name.

• --build: Build the generated project files.

• If gcc is part of the name, GCC is assumed.

• If clang is part of the name, clang is assumed.

• If Win32 is part of the name, a 32 bit Windows build is assumed.

• If Win64 is part of the name, a 64 bit Windows build is assumed.

To get a list of all the options:

rtime-make -h

To get help for a specific target:

rtime-make --target <target> --help

5.2.4.2. Manually Building with CMake

5.2.4.2.1. Preparing for a Build

As mentioned, it is recommended to create a unique directory for each build configuration. A build configuration can be created to address specific architectures, compiler settings, or different Connext DDS Micro build options.

RTI recommends assigning a descriptive name to each build configuration, using a common format. While there are no requirements to the format for functional correctness, the tool-chain files in Cross-Compiling Connext DDS Micro uses the RTIME_TARGET_NAME variable to determine various compiler options and selections.

RTI uses the following name format:

{cpu}{OS}{compiler}_{config}

In order to avoid a naming conflict with RTI, the following name format is recommended:

{prefix}_{cpu}{OS}{compiler}_{config}

Some examples:

• acme_ppc604FreeRTOSgcc4.6.1 - Connext DDS Micro for a PPC 604 CPU running FreeRTOS compiled with gcc 4.6.1, compiled by acme.

• acme_i86Win32VS2015 - Connext DDS Micro for an i386 CPU running Windows XP or higher compiled with Visual Studio 2015, compiled by acme.

• acme_i86Linux4gcc4.4.5_test - a test configuration build of Connext DDS Micro for an i386 CPU running Linux 3 or higher compiled with gcc 4.4.5, compiled by acme.

Files built by each build configuration will be stored under RTIMEHOME/build/[Debug | Release]/<name>. These directories are referred to as build directories or RTIMEBUILD. The structure of the RTIMEBUILD depends on the generated build files and should be regarded as an intermediate directory.

5.2.4.2.2. Creating Build Files for Connext DDS Micro Using the CMake GUI

Start the CMake GUI, either from a terminal window or a menu.

Please note that the Cmake GUI does not set the CMAKE_BUILD_TYPE variable. This variable is used to determine the names of the Connext DDS Micro libraries. Thus, it is necessary to add CMAKE_BUILD_TYPE manually and specify either Debug or Release. To add this variable manually, click the ‘Add Entry’ button, specify the name as a string type.

As an alternative, rtime-make’s --gui option can be used. This option starts the CMake and also adds the CMAKE_BUILD_TYPE option when the CMake GUI exits.

Please note that when using Visual Studio or Xcode, it is important to build the same configuration as was specified with rtime-make’s --config option. While it is possible to build a different configuration from the IDE, selecting a different configuration does not update the build configuration generated for Connext DDS Micro.

The GUI should be started from the RTIMEHOME directory. If this is not the case, check that:

• The source directory is the location of RTIMEHOME.

• The binary directory is the location of RTIMEBUILD.

With the CMake GUI running:

• Press ‘Configure’.

• Select a generator. You must have a compatible tool installed to process the generated files.

• Select ‘Use default native compilers’.

• Press ‘Done’.

• Press ‘Configure’.

• Check ‘Grouped’.

• Expand RTIME and select your build options. All available build options for Connext DDS Micro are listed here.

• Type a target name for RTIME_TARGET_NAME. This should be the same as the <name> used to create the RTIMEBUILD directory, that is the RTIMEBUILD should be on the form <path>/<RTIME_TARGET_NAME>.

• Press ‘Configure’. All red lines should disappear. Due to how CMake works, it is strongly recommended to always press ‘Configure’ whenever a value is changed for a variable. Other variables may depend on the modified variable and pressing ‘Configure’ will mark those with a red line. No red lines means everything has been configured.

• Press ‘Generate’. This creates the build-files in the RTIMEBUILD directory. Whenever an option is changed and Configure is re-run, press Generate again.

• Exit the GUI.

Depending on the generator, do one of the following:

• For IDE generators (such as Eclipse, Visual Studio, Xcode) open the generated solution/project files and build the project/solution.

• For command-line tools (such as make, nmake, ninja) change to the RTIMEBUILD directory and run the build-tool.

After a successful build, the output is placed in RTIMEHOME/lib/<name>.

The generated build-files may contain different sub-projects that are specific to the tool. For example, when using Xcode or Visual Studio, the following targets are available:

• ALL_BUILD - Builds all the projects.

• rti_me_<name> - Builds only the specific library. Note that that dependent libraries are built first.

• ZERO_CHECK - Runs CMake to regenerate project files in case something changed in the build input. This target does not need to be built manually.

For command-line tools, try <tool> help for a list of available targets to build. For example, if UNIX makefiles were generated:

make help

5.2.4.2.3. Creating Build Files for Connext DDS Micro Using CMake from the Command Line

Open a terminal window in the RTIMEHOME directory and create the RTIMEBUILD directory. Change to the RTIMEBUILD directory and invoke cmake using the following arguments:

cmake -G <generator> -DCMAKE_BUILD_TYPE=<Debug | Release> \
      -DCMAKE_TOOLCHAIN_FILE=<toolchain file>  \
      -DRTIME_TARGET_NAME=<target-name>

Depending on the generator, do one of the following:

• For IDE generators (such as Eclipse, Visual Studio, Xcode) open the generated solution/project files and build the project/solution.

• For command-line tools (such as make, nmake, ninja) run the build-tool.

After a successful build, the output is placed in RTIMEHOME/lib/<name>.

The generated build-files may contain different sub-projects that are specific to the tool. For example, in Xcode and Visual Studio the following targets are available:

• ALL_BUILD - Builds all the projects.

• rti_me_<name> - Builds only the specific library. Note that that dependent libraries are built first.

• ZERO_CHECK - Runs CMake to regenerate project-files in case something changed in the build input. This target does not need to be built manually.

For command-line tools, try <tool> help for a list of available targets to build. For example, if UNIX makefiles were generated:

make help

5.2.4.2.4. CMake Flags used by Connext DDS Micro

The following CMake flags (-D) are understood by Connext DDS Micro and may be useful when building outside of the source bundle installed by RTI. An example would be incorporating the Connext DDS Micro source in a project tree and invoking cmake directly on the CMakeLists.txt provided by Connext DDS Micro.

• -DRTIME_TARGET_NAME=\<name\> - The name of the target (equivalant to --name to rtime-make). The default value is the name of the source directory.

• -DRTIME_CMAKE_ROOT=\<path\> - Where to place the CMake build files. The default value is <source>/build/cmake.

• -DRTIME_BUILD_ROOT=\<path\> - Where to place the intermediate build files. The default value is <source>/build.

• -DRTIME_SYSTEM_FILE=\<file\> or an empty string - This file can be used to set the PLATFORM_LIBS variable used by Connext DDS Micro to link with. If an empty string is specified no system file is loaded. This option may be useful when cmake can detect all that is needed. The default value is not defined, which means try to detect the system to build for.

• -DRTI_NO_SHARED_LIB=true - Do not build shared libraries. The default is undefined, which means shared libraries are built. NOTE: This flag must be undefined to build shared libraries. Setting the value to false is not supported.

• -DRTI_MANUAL_BUILDID=true - Do not automatically generate a build ID. The default value is undefined, which means generate a new build each time the libraries are built. Setting the value to false is not supported. The build ID is in its own source and only forces a recompile of a few files. Note that it is necessary to generate a build ID at least once (this is done automatically). Also, a build ID is not supported for cmake versions less than 2.8.11 because the TIMESTAMP function does not exist.

5.2.5. Connext DDS Micro Compile Options

The Connext DDS Micro source supports compile-time options. These options are in general used to control:

• Enabling/Disabling features.

• Inclusion/Exclusion of debug information.

• Inclusion/Exclusion of APIs.

• Target platform definitions.

• Target compiler definitions.

NOTE: It is no longer possible to build a single library using CMake. Please refer to Custom Build Environments for information on customized builds.

5.2.5.1. Connext DDS Micro Debug Information

Please note that Connext DDS Micro debug information is independent of a debug build as defined by a compiler. In the context of Connext DDS Micro, debug information refers to inclusion of:

• Logging of error-codes.

• Tracing of events.

• Precondition checks (argument checking for API functions).

Unless explicitly included/excluded, the following rule is used:

• For CMAKE_BUILD_TYPE = Release, the NDEBUG preprocessor directive is defined. Defining NDEBUG includes logging, but excludes tracing and precondition checks. Please note that all logging is disabled in Connext DDS Micro Cert release libraries.

• For CMAKE_BUILD_TYPE = Debug, the NDEBUG preprocessor directive is undefined. With NDEBUG undefined, logging, tracing and precondition checks are included.

To manually determine the level of debug information, the following options are available:

• OSAPI_ENABLE_LOG (Include/Exclude/Default)

  • Include - Include logging.

  • Exclude - Exclude logging.

  • Default - Include logging based on the default rule.

• OSAPI_ENABLE_TRACE (Include/Exclude/Default)

  • Include - Include tracing.

  • Exclude - Exclude tracing.

  • Default - Include tracing based on the default rule.

• OSAPI_ENABLE_PRECONDITION (Include/Exclude/Default)

  • Include - Include tracing.

  • Exclude - Exclude tracing.

  • Default - Include precondition checks based on the default rule.

5.2.5.2. Connext DDS Micro Platform Selection

The Connext DDS Micro build system looks for target platform files in RTIMEHOME/include/osapi. All files that match *osapi_os_*.h are listed under RTIME_OSAPI_PLATFORM. Thus, if a new port is added it will automatically be listed and available for selection.

The default behavior, <auto detect>, is to try to determine the target platform based on header-files. The following target platforms are known to work:

• Linux

• VOS

• QNX

• Darwin

• Win32

• VxWorks 6.9 and later

However, for custom ports this may not work. Instead the appropriate platform definition file can be selected here.

5.2.5.3. Connext DDS Micro Compiler Selection

The Connext DDS Micro build system looks for target compiler files in RTIMEHOME/include/osapi. All files that match *osapi_cc_*.h are listed under RTIME_OSAPI_COMPILER. Thus, if a new compiler definition file is added it will automatically be listed and available for selection.

The default behavior, <auto detect>, is to try to determine the target compiler based on header-files. The following target compilers are known to work:

• GCC (stdc)

• clang (stdc)

• MSVC (stdc)

However, for others compilers this this may not work. Instead the appropriate compiler definition file can be selected here.

5.2.5.4. Connext DDS Micro UDP Options

Checking the RTIME_UDP_ENABLE_IPALIASES disables filtering out IP aliases. Note that this currently only works on platforms where each IP alias has its own interface name, such as eth0:1, eth1:2, etc.

Checking the RTIME_UDP_ENABLE_TRANSFORMS_DOC enables UDP transformations in the UDP transport.

Checking the RTIME_UDP_EXCLUDE_BUILTIN excludes the UDP transport from being built.

5.2.6. Cross-Compiling Connext DDS Micro

Cross-compiling the Connext DDS Micro source-code uses the exact same process described in Compiling Connext DDS Micro, but requires a additonal tool-chain file. A tool-chain file is a CMake file that describes the compiler, linker, etc. needed to build the source for the target. Connext DDS Micro includes a few basic, generic tool-chain files for cross-compilation. In general it is expected that users will provide their own cross-compilation tool-chain files.

To see a list of available targets, use --list :

rtime-make --list

By convention, RTI only provides generic tool-chain files that can be used to build for a broad range of targets. For example, the Linux target can be used to build for any Linux architecture as long as it is a self-hosted build. The same is true for Windows and Darwin systems. The VxWorks tool-chain file uses the Wind River environment variables to select the compiler.

For example, to build on a Linux machine with Kernel 2.6 and gcc 4.7.3:

rtime-make --target Linux --name i86Linux2.6gcc4.7.3 --config Debug --build

By convention, a specific name such as i86Linux2.6gcc4.4.5 is expected to only build for a specific target architecture. Note however that this cannot be enforced by the script provided by RTI. To create a target specific tool-chain file, copy the closest matching file and add it to the RTIMEHOME/source/Unix/resource/CMake/architectures or RTIMEHOME/source/windows/resource/CMake/architectures directory.

Once a tool-chain file has been created, or a suitable file has been found, edit it as needed. Then invoke rtime-make, specifying the new tool-chain file as the target architecture. For example:

rtime-make --target i86Linux2.6gcc4.4.5 --config Debug --build

5.2.7. Custom Build Environments

The preferred method to build Connext DDS Micro is to use CMake. However, in some cases it may be more convenient, or even necessary, to use a custom build environment. For example:

• Embedded systems often have numerous compiler, linker and board specific options that are easier to manage in a managed build.

• The compiler cannot be invoked outside of the build environment, it may be an integral part of the development environment.

• Sometimes better optimization may be achieved if all the components of a project are built together.

• It is easier to port Connext DDS Micro.

5.2.7.1. Importing the Connext DDS Micro Code

The process for importing the Connext DDS Micro Source Code into a project varies depending on the development environment. However, in general the following steps are needed:

• Create a new project or open an existing project.

• Import the entire Connext DDS Micro source tree from the file-system. Note that some environments let you choose whether to make a copy only link to the original files.

• Add the following include paths:

  • <root>/include

  • <root>/src/dds_c/domain

  • <root>/src/dds_c/infrastructure

  • <root>/src/dds_c/publication

  • <root>/src/dds_c/subscription

  • <root>/src/dds_c/topic

  • <root>/src/dds_c/type

• Add a compile-time definition -DRTIME_TARGET_NAME="target name" (note that the ” must be included).

• Add a compile-time definition -DNDEBUG for a release build.

• Add a compile-time definition of either -DRTI_ENDIAN_LITTLE for a little-endian platform or -DRTI_ENDIAN_BIG for a big-endian platform.

• If custom OSAPI definitions are used, add a compile-time definition -DOSAPI_OS_DEF_H="my_os_file".

• If custom compiler definitions are used, add a compile-time definition -DOSAPI_CC_DEF_H="my_cc_file.h" .