CMake: Use toolchain files

[chfast]

No description provided.

[chfast]

Wait with this. I see a lot of failures.

[axic]

@chfast are you still working on this?

[chfast]

Not actively.

I have problem with Emscripten - I'm not able to mix C++11 toolchain with Emscripten toolchain. Everytime I touch something related to Emscripten the Travis build fails without enough information in logs... I will go back to this some day, but probably not this week.

[axic]

@chfast was this problem resolved?

[chfast]

No. Emscripten toolchain is not fully supported by Hunter and you cannot build Boost this way.

[axic]

@chfast what should we do with this PR in that case?

[axic]

This should help by using the sane default from Emscripten via the toolchain file.

@chfast can this be finished somehow?

[chfast]

Yes, the idea it's simple: you have 2 toolchain files: one for regular C++11 builds, one for Emscripten builds.

But this not work in practice, because Hunter does not support building boost with Emscripten this way. It requires some work there, probably quite time consuming.

[axic]

@chfast are you saying this PR should be abandoned or not?

If it should be abandoned, does it still make sense creating an issue and linking here so that someone in the future might pick it up?

[axic]

@ekpyron here's another CMake PR to think about.

[ekpyron]

@axic Yes - I like this one. I think we should decide about #4486 first, though - it should make things easier.

[axic]

@ekpyron are you still working on this?

[ekpyron]

@axic Not right now, but looking into this and generally improving the build system is on my list.

[axic]

Rebased.

[axic]

@ekpyron @chfast wow this actually works after we've merged the emscripten updates.

[codecov]

Codecov Report

Merging #2836 into develop will decrease coverage by 0.3%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #2836      +/-   ##
===========================================
- Coverage    88.33%   88.03%   -0.31%     
===========================================
  Files          339      312      -27     
  Lines        32789    31371    -1418     
  Branches      3912     3752     -160     
===========================================
- Hits         28965    27616    -1349     
- Misses        2493     2500       +7     
+ Partials      1331     1255      -76

Flag	Coverage Δ
#all	88.03% <ø> (-0.31%)	⬇️
#syntax	29.07% <ø> (+0.75%)	⬆️

[chriseth]

Moving from "needs review" to "in progress" as the title says "WIP".

[axic]

Moving from "needs review" to "in progress" as the title says "WIP".

The title wrongfully said it after. It needs to be reviewed.

[axic]

Rebased this and updated to C++14, not sure if it works anymore.

[chriseth]

What is this about? What is the benefit?

[axic]

I think the main benefit is to properly (aka cmake style) set the compiler version. @chfast can answer better probably.

[chriseth]

Seems to be fine.

[chriseth]

Looks good, but we should also change the

[chfast]

This is a way to extend some CMake settings to dependencies. Hunter relay on this. E.g. you can have a toolchain file that configures the build for Emscripten and "magically" whole project will cross-compile with Emscripten.
But this allows you also do something simpler without adding additional options to project, e.g. compile in C++14 mode.

There are my example toolchains: https://github.com/ethereum/cable/tree/master/toolchains
I also have a -march=native somewhere for benchmarking.

Here are more: https://github.com/ruslo/polly.