Port to dune

[TheLortex]

In the global effort of switching mirage to dune: mirage/mirage#969
Fixes #41

This is a work in progress, I'm trying to keep track of every change that need to be made!

[avsm]

I realise that the -Werror is existing behaviour, but it makes it really painful when doing production builds with a newer compiler that introduces some random warning.

[hannesm]

I share your concerns, but IMHO such a change (removing -Werror) deserves its own PR rather than being included (hidden) in a build-system-changing PR. Out of curiousity, is it possible in dune to specify specific development vs release c_flags (so there could be -Werror in development mode)?

[mato]

On Saturday, 25.05.2019 at 16:48, Anil Madhavapeddy wrote: avsm commented on this pull request. > @@ -0,0 +1,18 @@ +(library + (name oS) + (public_name mirage-solo5.internals) + (modules lifecycle main mM oS solo5 time) + (c_names alloc_pages_stubs atomic_stubs barrier_stubs checksum_stubs clock_stubs cstruct_stubs main mm_stubs solo5_block_stubs solo5_console_stubs solo5_net_stubs) + (c_flags (:include cflags) -O2 -std=c99 -Wall -Werror) I realise that the -Werror is existing behaviour, but it makes it really painful when doing production builds with a newer compiler that introduces some random warning.

Isn't that consistent with Dune behaviour for OCaml code, i.e. treating all warnings as errors by default? Why deal with C code differently?

[avsm]

Almost is, but not quite. Dune has profiles, and in the default dev mode it treats warnings as errors. But if dune build --profile=release or dune build -p <package is specified its in release mode, and they are just warnings. We could do something similar by creating a (profile) in the dune-project that adds -Werror to CFLAGS only in dev builds

[emillon]

if configurator is used, it's possible to pass it the selected profile as argument, and the configure binary can output -Werror or not based on this piece of info.

[TheLortex]

@hannesm We can make a first PR that put solo5-specific modules in an Os_solo5 module and update mirage-(block|net|*)-solo5 accordingly. And then we can make Os an implementation of mirage-os-shim. What do you think ?