An STL inspired embedded library both for C and C++

(Nested) Embedded standard library

Note: Please use the new library named luepp instead: https://github.com/mlutken/luepp

Motivation

This library aims to provide a way for mainly embedded software project to use the functionality from the Standard Template Library.

The problem commonly faced on embedded platforms is that you can often only use the "Free standing" C++ implementation and thus you will run into problems when trying to use the compiler supplied STL implementation.

In plain C99 projects you don't have anything like an STL library so here people often "re-invent the wheel" all over the project implementing ad hoc vectors. list etc.

Performance and multithreading A secondary goal with this library is to provide classes (also in C) for performance critical projects like games where you often want to avoid dynamic allocation and need to use effective lock free structures like for example queues.

Current features C++

Support for C++03 and newer for most features. Some things like move semantics and the coming non dynamically allocation estl::function will need C++11 or newer.

• vector_s: A statically allocated vector that otrherwise behaves as your friendly std::vector. So it's not the same as std::array!
• map_s: A statically allocated map. It works by using an internal vector_s, which is then sorted.
• atomic: Simple atomic for integer types only.
• mutex: Simple mutex and lock_guard.
• srsw_fifo: Single reader, single writer lockless fifo.
• mrsw_fifo: (planned) Multiple reader, single writer lockless fifo.
• srmw_fifo: (planned) Single reader, multiple writer lockless fifo.
• mrmw_fifo: (planned) Multiple reader, multiple writer lockless fifo.
• shared_ptr: Simple shared_ptr and weak_ptr implementation.
• unique_ptr: (planned)Simple unique_ptr. C++11 and newer only!
• state_machine: A novel approach to state machines. Emphasis on splitting state changes from actions. Easily create unit tests that tests all transitions instantly. Can draw Graphviz "dot" state machie diagrams directly from the C++ code!

Current features C

• alignment: Simple platform abstraction for aligning variables.
• atomic: Simple atomic functions.
• cesl_vector_s: vector_s like container.
• cesl_srsw_fifo: (planned) Single reader, single writer lockless fifo. Current implmentation is named cesl_llfifo and needs to be renamed and tested.
• cesl_mrsw_fifo: (planned) Multiple reader, single writer lockless fifo. Current implmentation is named cesl_llfifo and needs to be renamed and tested.
• cesl_srmw_fifo: (planned) Single reader, multiple writer lockless fifo. Current implmentation is named cesl_llfifo and needs to be renamed and tested.
• cesl_mrmw_fifo: (planned) Multiple reader, multiple writer lockless fifo. Current implmentation is named cesl_llfifo and needs to be renamed and tested.
• cesl_format: C++ like type safe and MISRA compliant formatting of strings in C. An alternative to printf like formatting.
• cesl_debug: Using the above formatting functionality, this is a way to do safe debug printf like output from C.

CMake

For anyone looking for a good "template" for a new project that uses CMake as build system I believe you will find this project usefull. I have tried to the best of my effort to use the most recent best practices in regards to CMake.

Using in existing non CMake projects

The code is written using CMake a little as possible for platfor specific stuff, leaving most of this in plain header files using the C/C++ preprocessor. Thus it's relatively simple to simply add all the .c and .cpp files into your own build system and set a few preprocessor macros on your compiler command line. These are the relevant ones. (see more in the root CMakeLists.txt file, tools/cmake/default_versions.cmake, config/nestle_default_config.h ).

• -DCXX_STANDARD_LIBRARY=(Possible values: 98, 11, 14, 17, 20)
• -DCXX_STANDARD=(Possible values: 98, 11, 14, 17, 20)
• -DC_STANDARD=(Possible values: 99)
• -DNESTLE_PLATFORM_TYPE=(Possible values: 1 (NESTLE_PLATFORM_TYPE_DESKTOP), 2 (NESTLE_PLATFORM_TYPE_EMBEDDED))
• -DNESTLE_SYSTEM_NAME=(Possible values: 1 (NESTLE_SYSTEM_NAME_LINUX), 2 (NESTLE_SYSTEM_NAME_WINDOWS), 3 (NESTLE_SYSTEM_NAME_OSX), 4 (NESTLE_SYSTEM_NAME_FREERTOS) )

Some CMake "features" worth mentioning:

• Multiple platform support, using toolchain files for cross compiling
• Libraries use the CMake target_xx commands which makes sure that dependencies, includes, linker paths etc. are "inherited" by other libraries or executables that "depend" on them.
• Unit test subdirectories called "unittest" in each subfolder, which uses gtest. It's very easy to add a new unit test file in these subdirectories.
• Playground subdirectories called "playground", where you can easily add simple executables usefull for any adhoc testing.

Lastly: I highly recommend using this project from within the freely available QTCreator. It's really fast and capable IDE for C and C++ code - also when you don't use any QT classes at all.

Known limitations

• Windows support has not been tested at all yet. Should not be complicated to add though.
• Mac support has not been tested at all yet. Should not be complicated to add though.

Building

Building on Linux

$ git clone https://github.com/mlutken/nestle.git $ mkdir -p _build/nestle $ cd _build/nestle/ $ cmake ../../nestle $ make -j ... Or Use QtCreator or any otherway you prefer when dealing with CMake projects.