cf482c5d46
- Add libstdcpp feature to indicate a platform is providing a libstdc++ implementation ready for use - The existing cpp feature now only indicates a working C++ toolchain without libstdc++. (E.g. still useful for the Arduino compatibility layer.) - Added libstdcpp as required feature were needed - Added some documentation on C++ on RIOT
51 lines
2.0 KiB
Markdown
51 lines
2.0 KiB
Markdown
Using C++ in RIOT {#using-cpp}
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=================
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[TOC]
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Levels of Support {#levels-of-support}
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=================
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A CPU in RIOT can have three levels of support for C++ code:
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1. No support for C++ at all
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2. C++ is supported, but no libstdc++ implementation is available
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3. C++ is supported and a libstdc++ implementation is available
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The reason for missing or only partial C++ support can be one (or more) of
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the following:
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- No libstdc++ implementation for the target platform is available to RIOT, or
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the official RIOT docker image is missing it
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- Missing toolchain support for a given target platform
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- The C++ toolchain requires library code (such as constructor guards for the
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thread safe initialization of statically allocated instances) or hooks in
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the startup process to perform initialization
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Using C++
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=========
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In order for C++ code to compile with RIOT, the following needs to be done:
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- All C++ files must have the file extension `.cpp`, all C++ headers `.hpp`
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- For external code, overwriting the make variable `SRCXXEXT` e.g. to
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`cxx` can be used to compile C++ files with other extensions, e.g. `.cxx`
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- `FEATURES_REQUIRED += cpp` must be added to the applications `Makefile`
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- If additionally the libstdc++ is used, `FEATURES_REQUIRED += libstdcpp`
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must be used additionally
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RIOT Modules in C++ {#cpp-in-riot}
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===================
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RIOT modules should be written in C, so that boards/platforms without or partial
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C++ support can still use these modules. However, external modules, packages,
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and modules that require C++ support anyway (e.g. the Arduino compatibility
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features) can be written in C++. These modules/packages have to depend on the
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`cpp` feature (`FEATURES_REQUIRED += cpp`) and possibly the `libstdcpp`
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feature using their `Makefile.dep`.
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See Also {#see-also}
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========
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@ref sys_c11_atomics_cpp_compat, @ref cpp11-compat
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