example2

Example 2 - Use iidm4cpp in a CMake project

This example shows how to create a cmake project that uses iidm4cpp. This example uses the source code of the example 1 to produce the same executable, but as an external CMake project.

Requirements

To build this example, you need to compile and install the libraries following the build instructions. In this example, we'll consider that the libraries have been install in the /tmp/powsybl-iidm4cpp folder:

$> cd powsybl-iidm4cpp
$> mkdir build
$> cd build
$> cmake .. -DCMAKE_INSTALL_PREFIX=/tmp/powsybl-iidm4cpp
$> make
$> make install

During the installation, the headers, the libraries and the cmake scripts are copied to the prefix directory:

$> tree /tmp/powsybl-iidm4cpp
/tmp/powsybl-iidm4cpp
├── include
│   └── powsybl
│       ├── AssertionError.hpp
│       ├── iidm/...
│       ├── logging/...
│       ├── math/...
│       ├── network/...
│       ├── PowsyblException.hpp
│       ├── stdcxx/...
│       ├── test/...
│       └── xml/...
├── lib
│   ├── libiidm.a
│   ├── libiidm-ext-entsoe.a
│   ├── libiidm-ext-entsoe.so -> libiidm-ext-entsoe.so.1
│   ├── libiidm-ext-entsoe.so.1 -> libiidm-ext-entsoe.so.1.1.0
│   ├── libiidm-ext-entsoe.so.1.1.0
│   ├── libiidm-ext-iidm.a
│   ├── libiidm-ext-iidm.so -> libiidm-ext-iidm.so.1
│   ├── libiidm-ext-iidm.so.1 -> libiidm-ext-iidm.so.1.1.0
│   ├── libiidm-ext-iidm.so.1.1.0
│   ├── libiidm.so -> libiidm.so.1
│   ├── libiidm.so.1 -> libiidm.so.1.1.0
│   ├── libiidm.so.1.1.0
│   ├── libiidm-tests.so
│   └── libiidm-tests-static.a
└── LibIIDM
    └── cmake
        ├── libiidm-config.cmake
        ├── libiidm-config-debug.cmake
        └── libiidm-config-version.cmake

Create the cmake project

The cmake scripts, installed in the <PREFIX>/LibIIDM/cmake are used by the find_package instruction to load all the exported targets during the configuration of the project. The CMakeLists.txt below shows how to create a small project using iidm4cpp:

# Force a minimum CMake version
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

# Declare the project
project(my-project)

# Find the required dependencies: Boost, LibXML2 and IIDM and import the targets
find_package(Boost 1.56 REQUIRED COMPONENTS date_time filesystem program_options system unit_test_framework)
find_package(LibXml2 REQUIRED)
find_package(LibIIDM REQUIRED)

# Create an executable
add_executable(my-executable ../example1/main.cpp)

# Link the executable with the IIDM shared library
target_link_libraries(my-executable PRIVATE IIDM::iidm)

Configure and build the project

To configure the project, pass the -DCMAKE_PREFIX_PATH=<IIDM4CPP_PREFIX> option to the cmake command, where IIDM4CPP_PREFIX is the folder where the libraries have been installed. In this example, the libraries have been installed in the /tmp/powsybl-iidm4cpp directory:

$> cmake -DCMAKE_PREFIX_PATH=/tmp/powsybl-iidm4cpp
-- Boost version: 1.66.0
-- Found the following Boost libraries:
--   date_time
--   filesystem
--   program_options
--   system
--   unit_test_framework
-- Configuring done
-- Generating done
-- Build files have been written to: /home/user/powsybl-iidm4cpp/examples/example2/build

Once the project have been configured, compile the project running the following command:

$> cmake --build .
[ 50%] Building CXX object CMakeFiles/my-executable.dir/home/user/powsybl-iidm4cpp/examples/example1/main.cpp.o
[100%] Linking CXX executable my-executable
[100%] Built target my-executable

Run the program

You can run the program we just compile, running the following command:

$> ./my-executable
Usage: ./my-executable <input-file> <output-file>

Going further

In this example, the executable my-executable is linked to the shared library:

$> ldd my-executable 
        linux-vdso.so.1 (0x00007ffc6f51c000)
        libiidm.so.1 => /tmp/powsybl-iidm4cpp/lib/libiidm.so.1 (0x00007f8c38f03000)
        libxml2.so.2 => /lib64/libxml2.so.2 (0x00007f8c38d70000)
        libboost_filesystem.so.1.66.0 => /lib64/libboost_filesystem.so.1.66.0 (0x00007f8c38d53000)
        libboost_system.so.1.66.0 => /lib64/libboost_system.so.1.66.0 (0x00007f8c38d4c000)
        libdl.so.2 => /lib64/libdl.so.2 (0x00007f8c38d46000)
        libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f8c38bae000)
        libm.so.6 => /lib64/libm.so.6 (0x00007f8c38a28000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f8c38a0d000)
        libc.so.6 => /lib64/libc.so.6 (0x00007f8c38847000)
        libz.so.1 => /lib64/libz.so.1 (0x00007f8c3882d000)
        liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f8c38804000)
        librt.so.1 => /lib64/librt.so.1 (0x00007f8c387fa000)
        libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f8c387d7000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f8c3ad23000)

It's also possible to link with the static version, by replacing the IIDM::iidm target by IIDM::iidm-static in the CMakeLists.txt file:

# Link the executable with the IIDM static library
target_link_libraries(my-executable PRIVATE IIDM::iidm-static)

Then, rebuild the project:

$> cmake --build .
-- Boost version: 1.66.0
-- Found the following Boost libraries:
--   date_time
--   filesystem
--   program_options
--   system
--   unit_test_framework
-- Configuring done
-- Generating done
-- Build files have been written to: /home/user/powsybl-iidm4cpp/examples/example2/build
Scanning dependencies of target my-executable
[ 50%] Building CXX object CMakeFiles/my-executable.dir/home/user/powsybl-iidm4cpp/examples/example1/main.cpp.o
[100%] Linking CXX executable my-executable
[100%] Built target my-executable