TSInstall errors with clang set as compiler

[bhavitsharma]

Describe the bug

TSInstall cpp fails to compile when using clang as a compiler on nixos.

To Reproduce
env CC=$(which clang) nvim '+TSInstallSync cpp'

Expected behavior
Should compile

Output of :checkhealth nvim_treesitter

Output of nvim --version

NVIM v0.5.0-dev Build type: Release LuaJIT 2.1.0-beta3 Compilation: Compiled by nixbld

Features: +acl +iconv +tui
See ":help feature-compile"

system vimrc file: "$VIM/sysinit.vim"
fall-back for $VIM: "
/nix/store/bqfq1sz0ifjf6gnz6j6iqx5015p4yz1d-neovim-unwrapped-master/share/nvim

Run :checkhealth for more info


Additional context

src/scanner.cc:2:10: fatal error: 'string' file not found                                       
#include <string>                                                                               
         ^~~~~~~~                                                                               
1 error generated.                                                                              
Error detected while processing command line:                                                   
Error during compilation                                                                        
Failed to execute the following command:                                                        
{                                                                                               
  cmd = "clang",                                                                                
  err = "Error during compilation",                                                             
  info = "Compiling...",                                                                        
  opts = {                                                                                      
    args = { "-o", "parser.so", "-I./src", "src/parser.c", "src/scanner.cc", "-shared", "-Os", "
-lstdc++", "-fPIC" },                                                                           
    cwd = "/home/bhavit/.local/share/nvim/tree-sitter-cpp"                                      
  }                                                                                             
}    

I am using homemanager for managing my dotfiles and here's my config for nvim.nix.

home.packages = with pkgs; [
    neovim-nightly
    clang-tools
    rls
    sumneko-lua-language-server
    fzf
    ripgrep
    tree-sitter
    llvmPackages_12.llvm
    clang_12
    haskell-language-server
    clangStdenv
    clangMultiStdenv
];
xdg.configFile."nvim" = {
    source = ../nvim;
    recursive = true;
};

[bhavitsharma]

I think this is a problem with clang. When I tried to clone the repo and compile using clang -o parser.so -I./src src/parser.c src/scanner.cc -lstdc++ -fPIC, it gave the same error

[theHamsta]

Apple Clang? It's somehow not entering C++ mode. But you have GCC's stdc++ installed?

[bhavitsharma]

Stupid me: using clang++ worked. require 'nvim-treesitter.install'.compilers = { 'clang++'} worked.

[theHamsta]

@bhavitsharma But it should also work with clang. clang++ will not always handle C files so you've got the inverse problem.

[bhavitsharma]

I guess then it's a problem with my nix configuration rather than treesitter because I can't compile even this with clang.

#include <string>
int main() { 
return 0;
}

clang temp.cpp. Using clang++ works fine.

[theHamsta]

But it can happen that clang++ fails with CStruct = { .foo=1, .bar=2 }

[bhavitsharma]

I think C++ 17 has supports for designated initializers for struct :) but I get your point. I am not sure if the issue with clang is reproducible in other platforms? Quick internet search reveals to use clang -x c++ but I am not sure. The general recommendation to compile c++ files is to use clang++ instead of clang.

[YodaEmbedding]

I'm on Neovim 0.5 with compat branch.

• Arch Linux: no installation problems.
• NixOS: can't compile because of missing C++ headers (cwctype, algorithm, ...).

Workaround

Create a default.nix:

{ pkgs ? import <nixpkgs> {} }:

with pkgs;
pkgs.mkShell {
  buildInputs = [
    gcc
    nodejs
    neovim
    tree-sitter
    (python39.withPackages (pp: with pp; [
      pynvim
    ]))
  ];
}

Run nix-shell --command 'nvim' and run :TSInstall all.

---

Old instructions:

require("nvim-treesitter.install").compilers = { "clang++" }

require("nvim-treesitter.configs").setup {
  ensure_installed = "all",
}

This worked for all language parsers except tree-sitter-rst, tree-sitter-svelte, and tree-sitter-vim. For those, I had to comment out the line:

-- require("nvim-treesitter.install").compilers = { "clang++" }

...and ran nvim again so that the remaining three also installed.

---

Discussion

My NixOS configuration was pretty vanilla (just installing packages), so I think the culprit is somewhere in nvim-treesitter. Outside of nvim, running cargo build --release on each of the parsers individually successfully builds them without errors. ...So evidently, it's not really the fault of the tree-sitter-<lang> repositories themselves.

---

Relevant thread: https://www.reddit.com/r/neovim/comments/oa3xq8/how_to_install_nvimtreesitter_on_nixos/

[YodaEmbedding]

I found a way to reproduce the error. If you have clang/glibc/musl installed, everything goes haywire.

{ pkgs ? import <nixpkgs> {} }:

with pkgs;
pkgs.mkShell {
  buildInputs = [
    gcc
    nodejs
    neovim
    tree-sitter
    (python39.withPackages (pp: with pp; [
      pynvim
    ]))

    # Including this suddenly breaks TSInstall:
    clang glibc musl
  ];
}

Everything works fine without clang/glibc/musl.

---

Should this bug be reopened?

[theHamsta]

@bhavitsharma only in C++20. There is an open PR to use makefiles to compile c++ with clang++ and the C files with clang. But with only one command you can only use clamg

[Pablo1107]

Maybe this issue should still be open? I know there are workarounds, but should treesitter compile C++ files with clang++ instead of clang to avoid this issue?

[Luvjeet]

Stupid me: using clang++ worked. require 'nvim-treesitter.install'.compilers = { 'clang++'} worked.

where to write this code in init.lua?

[dongdongbh]

It worked after I changed my GCC version from gcc-9 to gcc-10.3. This may be helpful for anyone else who is experiencing the same problem.

[hallettj]

I'm another NixOS user, and I'm installing plugins with lazy.nvim instead of through Nix. If you got here because you are in a similar situation, and you are getting oodles of errors when you start neovim, my workaround is to avoid the whole clang issue by setting the grammar compiler to gcc.

I have this in my plugin config - since I'm using lazy.nvim I put this in the config callback for my nvim-treesitter plugin config (see in context):

require('nvim-treesitter.install').compilers = { 'gcc' }

And to make sure that gcc is available while running neovim I have neovim installed through Home Manager like this (see in context):

  programs.neovim = {
    enable = true;
    defaultEditor = true;
    withPython3 = true;
    extraPackages = with pkgs; [
      gcc
      # ...
    ];
  };