Building and using the Library {#build_lib}

@brief How to build the library and test programs and include the library in an application

Platform Support

The current makefiles and build projects support building the library on:

  • Linux and Windows, x86 or x64 hosts.
  • ARM linux - AArch32 and AArch64
  • ARM aarch32 and aarch64 libs, x-compiled on x86/64 hosts.

In addition to building the library from the project, the library may be installed into the standard /usr/lib/ area in Linux, and will soon be available as a package from Linux Distros.

Building the Library

The library and test programs are built from the library ./build/<platform> directory, where is either ‘linux’ or ‘win-vs2015’

See [./docs/test_progs.md](@ref test_progs) for further information on use of the test programs.

Linux x86/x64/ARM

Libraries are built into a <tgt_dir>. This is used as the final output directory for the libraries in decoder/lib/<tgt_dir>, and also as a sub-directory of the build process for intermediate files - decoder/build/linux/ref_trace_decode_lib/<tgt_dir>.

For a standard build, go to the ./build/linux/ and run make in that directory.

This will set <tgt_dir> to builddir for all build variants of the library. Using this only one variant of the library can be built at any one time.

For development, alternatively use make -f makefile.dev

This will set <tgt_dir> to linux<bit-variant>/<dbg|rel> and therefore build libraries into the decoder/lib/linux<bit-variant>/<dbg|rel> directories, allowing multiple variants of the library to be present during development.

e.g.

./lib/linux64/rel will contain the linux 64 bit release libraries.

./lib/linux-arm64/dbg will contain the linux aarch 64 debug libraries for ARM.

Options to pass to both makefiles are:-

  • DEBUG=1 : build the debug version of the library.

Options to pass to makefile.dev are:-

  • ARCH= : sets the bit variant in the delivery directories. Set if cross compilation for ARCH other than host. Otherwise ARCH is auto-detected. can be x86, x86_64, arm, arm64, aarch64, aarch32

For cross compilation, set the environment variable CROSS_COMPILE to the name path/prefix for the compiler to use. The following would set the environment to cross-compile for ARM

     export PATH=$PATH:~/work/gcc-x-aarch64-6.2/bin
     export ARCH=arm64
     export CROSS_COMPILE=aarch64-linux-gnu-

The makefile will scan the ocsd_if_version.h to get the library version numbers and use these in the form Major.minor.patch when naming the output .so files.

Main C++ library names:

  • libcstraced.so.M.m.p : shared library containing the main C++ based decoder library
  • libcstrace.so.M : symbolic link name to library - major version only.
  • libcstrace.so : symbolic link name to library - no version.

C API wrapper library names:

  • libcstraced_c_api.so.M.m.p : shared library containing the C-API wrapper library. Dependent on libcstraced.so.M
  • libcstraced_c_api.so.M : symbolic link name to library - major version only.
  • libcstraced_c_api.so : symbolic link name to library - no version.

Static versions of the libraries:

  • libcstraced.a : static library containing the main C++ based decoder library.
  • libcstraced_c_api.a : static library containing the C-API wrapper library.

Test programs are delivered to the ./tests/bin/<tgt_dir> directories.

The test programs are built to used the .so versions of the libraries.

  • trc_pkt_lister - dependent on libcstraced.so.
  • simple_pkt_print_c_api - dependent on libcstraced_c_api.so & hence libcstraced.so.

The test program build for trc_pkt_lister also builds an auxiliary library used by this program for test purposes only. This is the libsnapshot_parser.a library, delivered to the ./tests/lib/<tgt_dir> directories.

Installing on Linux

The libraries can be installed on linux using the make install command. This will usually require root privileges. Installation will be the version in the ./lib/<tgt_dir> directory, according to options chosen.

e.g. make -f makefile.dev DEBUG=1 install

will install from ./lib/linux64/dbg

The libraries libopencsd and libopencsd_c_api are installed to /usr/lib.

Sufficient header files to build using the C-API library will be installed to /usr/include/opencsd.

The installation can be removed using make clean_install. No additional options are necessary.

Windows (x86/x64)

Use the .\build\win\ref_trace_decode_lib\ref_trace_decode_lib.sln file to load a solution which contains all library and test build projects.

Libraries are delivered to the ./lib/win<bitsize>/<dbg\rel> directories. e.g. ./lib/win64/rel will contain the windows 64 bit release libraries.

The solution contains four configurations:-

  • Debug : builds debug versions of static C++ main library and C-API libraries, test programs linked to the static library.
  • Debug-dll : builds debug versions of static main library and C-API DLL. C-API statically linked to the main library. C-API test built as simple_pkt_print_c_api-dl.exe and linked against the DLL version of the C-API library.
  • Release : builds release static library versions, test programs linked to static libraries.
  • Release-dll : builds release C-API DLL, static main library.

Note: Currently there is no Windows DLL version of the main C++ library. This may follow once the project is nearer completion with further decode protocols, and the classes requiring export are established..

Libraries built are:-

  • libcstraced.lib : static main C++ decoder library.
  • cstraced_c_api.dll : C-API DLL library. Statically linked against libcstraced.lib at .DLL build time.
  • libcstraced_c_api.lib : C-API static library.

There is also a project file to build an auxiliary library used trc_pkt_lister for test purposes only. This is the snapshot_parser_lib.lib library, delivered to the ./tests/lib/win<bitsize>/<dgb\rel> directories.

Additional Build Options

Library Virtual Address Size

The ocsd_if_types.h file includes a #define that controls the size of the virtual addresses used within the library. By default this is a 64 bit uint64_t value.

When building for ARM architectures that have only a 32 bit Virtual Address, and building on 32 bit ARM architectures it may be desirable to build a library that uses a v-addr size of 32 bits. Define USE_32BIT_V_ADDR to enable this option

Including the Library in an Application

The user source code includes a header according to the API to be used:-

  • Main C++ decoder library - include opencsd.h. Link to C++ library.
  • C-API library - include opencsd_c_api.h. Link to C-API library.

Linux build

By default linux builds will link against the .so versions of the library. Using the C-API library will also introduce a dependency on the main C++ decoder .so. Ensure that the library paths and link commands are part of the application makefile.

To use the static versions use appropriate linker options.

Windows build

To link against the C-API DLL, include the .DLL name as a dependency in the application project options.

To link against the C-API static library, include the library name in the dependency list, and define the macro OCSD_USE_STATIC_C_API in the preprocessor definitions. This ensures that the correct static bindings are declared in the header file. Also link against the main C++ library.

To link against the main C++ library include the library name in the dependency list.