Crystal: Port Crystal to LLVM9

[anatol]

LLVM9 been released a while ago. Arch Linux team is looking what need to be done to bring the latest version of LLVM.

I am checking how crystal works with LLVM9. The project compiles fine with LLVM9. It seems LLVM9 does not have any breaking API changes.

$ crystal --version
Crystal 0.31.1 (2019-10-04)

LLVM: 9.0.0
Default target: x86_64-pc-linux-gnu

But when I try to compile a simple crystal app like this:

def main
  channel = Channel(Int32).new(9)

  (1..10).each do |i|
    spawn do
      channel.send(i)
    end
  end

  result = [] of Int32
  9.times do
    result << channel.receive
  end

  puts result
end

main

compilation fails:

$ crystal main.cr 
Missing hash key for value: 11 (KeyError)
Unhandled exception: Error opening file 'crystal' with mode 'r': No such file or directory (Errno)
Failed to raise an exception: END_OF_STACK
[0x56139e0bd3c6] ???
[0x56139d744e4b] __crystal_raise +43
[0x56139d746645] ???
[0x56139d75246b] ???
[0x56139d74b75c] ???
[0x56139d74adf4] ???
[0x56139daa8133] ???
[0x56139d75dd07] ???
[0x56139d7489c7] main +55
[0x7f8e21c1d153] __libc_start_main +243
[0x56139d74355e] _start +46
[0x0] ???

What does this Missing hash key for value: 11 mean?

[oprypin]

Can you suggest an easy way to reproduce this problem on Arch Linux?

[Blacksmoke16]

It's reproducible on mac if you build Crystal with llvm9. I included an example program and stack trace.

# app.cr
puts "hello world"

./bin/crystal app.cr

Using compiled compiler at `.build/crystal'
Missing hash key for value: 11 (KeyError)
  from src/hash.cr:1081:22 in 'key_for'
  from src/llvm/enums.cr:2:3 in 'from_kind'
  from src/llvm/function.cr:43:5 in 'attributes'
  from src/compiler/crystal/codegen/fun.cr:44:7 in 'declare_fun' 
  ...

Edited by @asterite : reduced the callstack, with the above we can know the problem seems to be in a difference of function attributes definition between LLVM 8 and 9.

[anatol]

@oprypin To reproduce the problem at Arch Linux please enable testing repositories. To achieve it please edit file /etc/pacman.conf and uncomment

[testing]
Include = /etc/pacman.d/mirrorlist
[community-testing]
Include = /etc/pacman.d/mirrorlist
[multilib-testing]
Include = /etc/pacman.d/mirrorlist

repositories and then update the system with pacman -Suy.

Arch testing repositories already contain LLVM9 and crystal package rebuilt on top of LLVM9.

[anatol]

@asterite

the problem seems to be in a difference of function attributes definition

Do you have a patch that we can use for testing with LLVM9 and see if it fixes our issue.

[asterite]

No, sorry. I was just hinting at the problem so maybe someone else can fix it (I don't have much time there days).

[anatol]

Hi folks, do you have any bugfix that we can test with llvm9? I would like to push the fix to Arch Linux repo and help to identify any possible problems with llvm9.

[bcardiff]

Hi @anatol, no. There is no support for llvm9 I am aware of.