Re: Partial libstdc++ Support

Matthijs Kooijman <[email protected]> Tue, 2 Feb 2021 13:27:08 +0100

Newsgroups	gmane.comp.hardware.avr.gcc
Message-ID	<[email protected]>

Hey John,

> Naturally, much of the C++ standard library isn't remotely suitable for
> AVRs, and should not be supported. However, there are a fair amount of
> features that I believe would work very nicely, and would be worthwhile
> to support.
I've been playing with the same thought for a while and briefly looked
into this.

It's worthwile to note that other embedded targets (notably ARM) seem to
just include the c++ standard libraries that come with gcc which
supports a lot of the useful stuff.

Then, I think avr *could* use the same approach, except that the
convention so far is to just disable the standard library on all avr-gcc
builds. Maybe because there are bugs or things not yet properly
implemented for AVR, but not using the standard library will in itself
lead to more bugs in AVR if you ever try to enable it.

Having said that, I think there have been some people in the past who
tried enabling the gcc c++ standard library for avr, which has indeed
seen some success. I've been meaning to try this as well with the
Arduino-built avr-gcc version or maybe the Debian version, which are the
versions I use most, but haven't found the time so far (probably will
not have time for this in the near future either).

From my previous look into this, I collected some links that might
prove useful. I'll share them here without further comment (I'd have to
look at them again to comment):

 - http://gcc.1065356.n8.nabble.com/avr-freestanding-libstdc-td1710708.html#a1710857
 - https://www.reddit.com/r/cpp/comments/esk2wy/standard_c_library_on_gccs_avr_target/
 - https://patchwork.ozlabs.org/project/gcc/patch/CADfx-VSmfye0Xe7xMWVFZKDZhQbwFcw7RbNYe=6irDJUzPtHzg@mail.gmail.com/
 - https://patches-gcc.linaro.org/patch/9338/
 - https://patches-gcc.linaro.org/patch/9338/
 - http://avr-libstdcxx.gitlab.io/

Gr.

Matthijs

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