Getting started

The fiction framework provides a stand-alone CLI tool as well as a C++17 header-only library and a Python module which can be used in external projects. Additionally, we provide an experimentation playground that can be used to quickly prototype new ideas or script evaluations.

We are continuously testing on Ubuntu, macOS, and Windows with multiple compilers and various Python versions. See the badges in the README file for more information.

Compilation requirements

The repository should always be cloned recursively with all submodules:

git clone --recursive

Several third-party libraries will be cloned within the libs folder. The cmake build process will take care of them automatically. Should the repository have been cloned before, the commands:

git submodule update --init --recursive

will fetch the latest version of all external modules used. Additionally, only CMake and a C++17 compiler are required.

At the time of writing, for parallel STL algorithms to work when using GCC, the TBB library (libtbb-dev on Ubuntu) is needed. It is an optional dependency that can be installed for a performance boost in certain scenarios. For your preferred compiler, see the current implementation state of P0024R2.

On Ubuntu, all required and optional dependencies can be installed via:

sudo apt-get install build-essential cmake libreadline-dev libtbb-dev

Using fiction as a stand-alone CLI tool

It is possible to compile fiction as a stand-alone CLI tool. For auto-completion in the CLI, it is recommended but not required to install the libreadline-dev package (see above). The build system CMake can be invoked from the command line as follows:

cmake . -B build
cd build
cmake --build . -j4

Several options can be toggled during the build. For a more interactive interface, please refer to ccmake for a full list of supported customizations.

The CLI tool can then be run using:


Here is an example of running fiction to perform a full physical design flow on a QCA circuit layout that can afterward be simulated in QCADesigner:

CLI example

See Using fiction as a stand-alone CLI tool for a full user guide.

As an alternative to this build workflow, the CLI tool is also available as an image for a Docker container. The respective Dockerfile is available in the base directory.

Using fiction as a header-only library

All data types and algorithms provided by fiction can be used independently to build custom projects. The following snippets illustrate how fiction can be included and linked against your project. Assume, the project is called fanfiction. Clone fiction within the project folder fanfiction/ and add the following lines of code to your CMakeLists.txt:

target_link_libraries(fanfiction libfiction)


The command target_link_libraries must be called after the respective add_executable statement that defines fanfiction.

By default fiction’s CLI is enabled and will be built, which can be time-consuming. If you do not need it, you can disable it by passing -DFICTION_CLI=OFF to your cmake call or adding set(FICTION_CLI OFF CACHE BOOL "" FORCE) before add_subdirectory(fiction/).

Within your code files, you can then call

#include <fiction/layouts/cell_level_layout.hpp>
#include <fiction/layouts/clocking_scheme.hpp>
#include <fiction/technology/qca_one_library.hpp>
#include <fiction/io/write_qca_layout.hpp>
#include <fiction/...>

for each used header file to include fiction’s data types and algorithms. Everything that can safely be used is directly located inside the fiction namespace.

Python Bindings

The Python bindings can be installed via pip from PyPI where we publish wheels for every new release:

pip install mnt.pyfiction

You can then import the bindings in your Python project:

from mnt import pyfiction

The Python synopsis is modeled after the C++ API to make it feel as familiar as possible. However, all available Python bindings are additionally documented together with the C++ code on this site to make it easier to get started. For each module, you can toggle between the two languages using the tabs.


The fiction framework is primarily developed for C++ as a header-only library. The Python bindings are a thin wrapper around the C++ code. We try our best to keep the bindings in sync with the C++ code, and to expose most of fiction’s functionality in both C++ and Python. This is, unfortunately, not always possible. Should you encounter features that are not (yet) available in pyfiction, please open an issue on GitHub.

Enabling dependent functions

Some functionalities require the presence of third-party dependencies. In the following, it is discussed how to enable them.

SMT-based exact P&R

The exact placement and routing algorithm utilizes the SMT solver Z3. Follow the installation instructions and call sudo make install to install headers, scripts, and the binary.


Be sure to compile Z3 in release mode to avoid performance issues when running fiction’s dependent functions! This can be achieved by passing -DCMAKE_BUILD_TYPE=Release to Z3’s cmake call.

Finally, before building fiction, pass -DFICTION_Z3=ON to the cmake call. It should be able to find Z3’s include path and link against the binary automatically if installed correctly. Otherwise, you can use -DZ3_ROOT=<path_to_z3_root> to set Z3’s root directory that is to be searched for the installed solver.

SAT-based onepass synthesis

The one-pass synthesis algorithm is embedded via the Python3 script Mugen by Winston Haaswijk using pybind11. It has some further Python dependencies that can be installed via pip3:

pip install -r libs/mugen/requirements.txt

The Python integration is experimental and may cause issues on some systems. It is currently not available on Windows and some macOS versions due to issues with python-sat. Mugen requires at least Python 3.7!

Finally, before building fiction, pass -DFICTION_ENABLE_MUGEN=ON to the cmake call.

Building experiments

The experiments folder provides a playground for quickly scripting some ideas by plugging algorithms together. A fictionlib_demo.cpp demonstrates the usage. Any *.cpp file that is placed in on of its sub-folders is automatically linked against libfiction and compiled as a stand-alone binary. Simply add a main function and include the desired header files to get started:

#include <fiction/layouts/cell_level_layout.hpp>
#include <fiction/layouts/clocking_scheme.hpp>
#include <fiction/technology/qca_one_library.hpp>
#include <fiction/io/write_qca_layout.hpp>
#include <fiction/...>

int main(int argc, char* argv[])
  // your code goes here

Each file can be built individually via CMake:

cd build
cmake --build . -j4

Building tests

Unit tests can be built with CMake via a respective flag on the command line and executed via ctest:

cmake . -B build -DFICTION_TEST=ON
cd build
cmake --build . -j4

Building code benchmarks

Using Catch2’s micro-benchmarking feature, you can compile and run code tests that evaluate the performance of certain code constructs. The test/benchmark folder provides a selection of benchmarks we were running to evaluate the performance of our code during development. Any *.cpp file that is placed in that folder is automatically linked against fiction and compiled as a stand-alone binary using the following commands:

cd build
cmake --build . -j4

Noteworthy CMake options

The following CMake options are available which have a potential positive impact on the build process, debugging attempts, or performance of the resulting binaries:

  • -DFICTION_ENABLE_IPO=ON: Enable IPO/LTO to improve performance of resulting binaries on some systems.

  • -DFICTION_ENABLE_PCH=ON: Enable precompiled headers (PCH) to speed up compilation.

  • -DFICTION_ENABLE_UNITY_BUILD=ON: Enable unity builds to speed up compilation.

  • -DFICTION_ENABLE_SANITIZER_ADDRESS=ON: Enable the address sanitizer to detect memory issues.

  • -DFICTION_ENABLE_SANITIZER_LEAK=ON: Enable the leak sanitizer to detect memory leaks.

  • -DFICTION_ENABLE_SANITIZER_UNDEFINED=ON: Enable the undefined behavior sanitizer to detect undefined behavior.

  • -DFICTION_ENABLE_SANITIZER_THREAD=ON: Enable the thread sanitizer to detect multithreading-related problems.

  • -DFICTION_ENABLE_SANITIZER_MEMORY=ON: Enable the memory sanitizer to detect uninitialized reads.


Since all tools were built locally, simply delete the git folder cloned initially to uninstall this project.