Add riscv64 PlatformSupport

[eschnett]

No description provided.

[giordano]

What's the corresponding PR to Yggdrasil?

[eschnett]

That's a complicated story... Adding a new architecture requires patches to BinaryBuilderBase, BinaryBuilder, and Julia itself. I'm building Yggdrasil packages with Julia 1.7, and it doesn't seem viable to have patches against it accepted.

At the moment this is just a test balloon to support RISC-V as a new architecture in general.

I think I'll start by opening a PR against Julia's master branch.

[giordano]

Ok, yeah, my next comment was going to be that it'll be complicated to have this going on with current incarnation of BinaryBuilder given adding new architectures/OSes requires changing in Julia, but we're currently stuck with Julia v1.7. https://github.com/JuliaPackaging/BinaryBuilder2.jl should improve the situation going forward, but we are definitely not there yet. But please do start with contributing changes to julia!

[eschnett]

The BinaryBuilder PR JuliaPackaging/BinaryBuilder.jl#1321.

[eschnett]

The BinaryBuilderBase PR: #375

[eschnett]

The Yggdrasil PR: JuliaPackaging/Yggdrasil#8468

[eschnett]

And the PR for Julia itself: JuliaLang/julia#54011

[oscardssmith]

Now that the julia side is merged, is this ready?

[giordano]

That's really not that easy. BinaryBuilder only works with julia v1.7, so the changes in Julia v1.12 won't help. I think whatever changes we need to do on this side will have to wait for BinaryBuilder2

[eschnett]

I have made corresponding changes to Julia 1.7. We could (i.e., I will have to) maintain a feature branch. This will allow us to go forward in the short term, and we can then merge some changes into BinaryBuilder, BinaryBuilderBase, and the Yggdrasil base image (or respective feature branches...)

[maleadt]

@eschnett Couldn't we pirate the definitions in to get this functionality in 1.7?

using Base: BinaryPlatforms

@static if !haskey(BinaryPlatforms.arch_mapping, "riscv64")

using .BinaryPlatforms: CPUID
CPUID.ISAs_by_family["riscv64"] = [
    # We have no way to test riscv64 features yet, so we're only going to declare the lowest ISA:
    "riscv64" => CPUID.ISA(Set{UInt32}()),
]

@eval Base.BinaryPlatforms begin
    function validate_tags(tags::Dict)
        throw_invalid_key(k) = throw(ArgumentError("Key \"$(k)\" cannot have value \"$(tags[k])\""))
        # Validate `arch`
        if tags["arch"] ∉ ("x86_64", "i686", "armv7l", "armv6l", "aarch64", "powerpc64le", "riscv64")
            throw_invalid_key("arch")
        end
        # Validate `os`
        if tags["os"] ∉ ("linux", "macos", "freebsd", "windows")
            throw_invalid_key("os")
        end
        # Validate `os`/`arch` combination
        throw_os_mismatch() = throw(ArgumentError("Invalid os/arch combination: $(tags["os"])/$(tags["arch"])"))
        if tags["os"] == "windows" && tags["arch"] ∉ ("x86_64", "i686", "armv7l", "aarch64")
            throw_os_mismatch()
        end
        if tags["os"] == "macos" && tags["arch"] ∉ ("x86_64", "aarch64")
            throw_os_mismatch()
        end

        # Validate `os`/`libc` combination
        throw_libc_mismatch() = throw(ArgumentError("Invalid os/libc combination: $(tags["os"])/$(tags["libc"])"))
        if tags["os"] == "linux"
            # Linux always has a `libc` entry
            if tags["libc"] ∉ ("glibc", "musl")
                throw_libc_mismatch()
            end
        else
            # Nothing else is allowed to have a `libc` entry
            if haskey(tags, "libc")
                throw_libc_mismatch()
            end
        end

        # Validate `os`/`arch`/`call_abi` combination
        throw_call_abi_mismatch() = throw(ArgumentError("Invalid os/arch/call_abi combination: $(tags["os"])/$(tags["arch"])/$(tags["call_abi"])"))
        if tags["os"] == "linux" && tags["arch"] ∈ ("armv7l", "armv6l")
            # If an ARM linux has does not have `call_abi` set to something valid, be sad.
            if !haskey(tags, "call_abi") || tags["call_abi"] ∉ ("eabihf", "eabi")
                throw_call_abi_mismatch()
            end
        else
            # Nothing else should have a `call_abi`.
            if haskey(tags, "call_abi")
                throw_call_abi_mismatch()
            end
        end

        # Validate `libgfortran_version` is a parsable `VersionNumber`
        throw_version_number(k) = throw(ArgumentError("\"$(k)\" cannot have value \"$(tags[k])\", must be a valid VersionNumber"))
        if "libgfortran_version" in keys(tags) && tryparse(VersionNumber, tags["libgfortran_version"]) === nothing
            throw_version_number("libgfortran_version")
        end

        # Validate `cxxstring_abi` is one of the two valid options:
        if "cxxstring_abi" in keys(tags) && tags["cxxstring_abi"] ∉ ("cxx03", "cxx11")
            throw_invalid_key("cxxstring_abi")
        end

        # Validate `libstdcxx_version` is a parsable `VersionNumber`
        if "libstdcxx_version" in keys(tags) && tryparse(VersionNumber, tags["libstdcxx_version"]) === nothing
            throw_version_number("libstdcxx_version")
        end
    end
end

BinaryPlatforms.arch_mapping["riscv64"] = "(rv64|riscv64)"

function get_set(arch, name)
    all = BinaryPlatforms.CPUID.ISAs_by_family[arch]
    return all[findfirst(x -> x.first == name, all)].second
end
BinaryPlatforms.arch_march_isa_mapping["riscv64"] =
    ["riscv64" => get_set("riscv64", "riscv64")]

end

[giordano]

Yeah, I'd be ok with a little hack like that, BinaryBuilder is typically used as a standalone application only, not as a library used by others, so it's kinda "safe" in this regard.

[eschnett]

@maleadt Do you want to create a PR against BinaryBuilderBase?

[maleadt]

I don't have the time to revisit this right now, so feel free to take over.

[giordano]

This conversation reads a bit surreal since it's a PR by Erik in BinaryBuilderBase 😂

But I want to try find time to push this forward in the near future.