CMake Integration Reference

fsmc provides CMake functions and imported targets that make integrating formal state machine compilation into CMake builds straightforward and maintainable.

---

1. Importing fsmc into CMake

When fsmc is imported via FetchContent or find_package(fsmc CONFIG REQUIRED), it defines:

• fsmc_runtime: An INTERFACE library containing runtime C++ header search paths and compile features (cxx_std_17 or cxx_std_20).
• fsmc::fsmc: The host executable target for the compiler driver.
• fsmc::fsm-opt: The host executable target for the formal IR optimizer.

---

2. The fsmc_target_sources Macro

The fsmc_target_sources macro hooks into your target's build graph, creating custom commands that transpile input models into C++ headers before your source files are compiled.

Signature

fsmc_target_sources(
    <TargetName>
    DIAGRAMS <diagram1> [<diagram2>...]
    [NAME <GeneratedFSMClassName>]
    [STANDARD <17|20>]
    [NAMESPACE <NamespaceName>]
    [OUTPUT_DIR <OutputDirectory>]
    [STANDALONE]
    [MODULAR]
    [NO_THREAD_SAFE]
    [NO_STUBS]
    [FORMAT <FormatName>]
    [TARGET_LANG <Language>]
)

Argument Reference

Parameter	Type	Description
<TargetName>	Target	The CMake target (executable or library) receiving the generated header.
DIAGRAMS	Files	List of input statechart files (.sysml, .puml, .mmd, .xmi, .scxml, .json, .dot).
NAME	String	Name of the generated C++ class (e.g. UavMissionFSM).
STANDARD	Integer	C++ standard version (17 or 20). Default: 17.
NAMESPACE	String	C++ namespace to enclose generated types. Default: fsm_generated.
OUTPUT_DIR	Path	Output directory for generated headers (default: ${CMAKE_CURRENT_BINARY_DIR}/generated_<target>).
STANDALONE	Flag	Generate self-contained header with embedded zero-alloc runtime.
MODULAR	Flag	Generate header that includes external runtime header (default: "fsm.hpp", matching --export-runtime).
RUNTIME_HEADER	String	Custom runtime header path included in modular mode (e.g. "fsm.hpp", "<fsm/fsm.hpp>").
NO_THREAD_SAFE	Flag	Disable generation of the thread_safe_fsm asynchronous wrapper.
NO_STUBS	Flag	Disable generation of default stubs for custom actions and guards.
FORMAT	String	Override input model format parser (sysml2, plantuml, mermaid, etc.).
TARGET_LANG	String	Target code generator language (cpp).

---

3. Complete Integration Example

cmake_minimum_required(VERSION 3.16)
project(AvionicsApp LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

include(FetchContent)
FetchContent_Declare(
    fsmc
    GIT_REPOSITORY https://github.com/simoneCavalleri/fsmc.git
    GIT_TAG        main
)
FetchContent_MakeAvailable(fsmc)

add_executable(avionics_app src/main.cpp src/sensors.cpp)
target_link_libraries(avionics_app PRIVATE fsmc_runtime)

# Generate header from SysML v2 model
fsmc_target_sources(avionics_app
    DIAGRAMS ${CMAKE_CURRENT_SOURCE_DIR}/models/flight_control.sysml
    NAME FlightControlFSM
    STANDARD 20
    NAMESPACE avionics
)