runtime: Add script for Python diagnostic information (#4885)

3 files changed, 451 insertions, 0 deletions

diff --git a/runtime/autoload/health.vim b/runtime/autoload/health.vim
new file mode 100644
index 0000000000..dc362577a6
--- /dev/null
+++ b/runtime/autoload/health.vim
@@ -0,0 +1,433 @@
+function! s:trim(s) abort
+  return substitute(a:s, '^\_s*\|\_s*$', '', 'g')
+endfunction
+
+
+" Simple version comparison.
+function! s:version_cmp(a, b) abort
+  let a = split(a:a, '\.')
+  let b = split(a:b, '\.')
+
+  for i in range(len(a))
+    if a[i] > b[i]
+      return 1
+    elseif a[i] < b[i]
+      return -1
+    endif
+  endfor
+
+  return 0
+endfunction
+
+
+" Fetch the contents of a URL.
+function! s:download(url) abort
+  let content = ''
+  if executable('curl')
+    let content = system('curl -sL "'.a:url.'"')
+  endif
+
+  if empty(content) && executable('python')
+    let script = "
+          \try:\n
+          \    from urllib.request import urlopen\n
+          \except ImportError:\n
+          \    from urllib2 import urlopen\n
+          \\n
+          \try:\n
+          \    response = urlopen('".a:url."')\n
+          \    print(response.read().decode('utf8'))\n
+          \except Exception:\n
+          \    pass\n
+          \"
+    let content = system('python -c "'.script.'" 2>/dev/null')
+  endif
+
+  return content
+endfunction
+
+
+" Get the latest Neovim Python client version from PyPI.  The result is
+" cached.
+function! s:latest_pypi_version()
+  if exists('s:pypi_version')
+    return s:pypi_version
+  endif
+
+  let s:pypi_version = 'unknown'
+  let pypi_info = s:download('https://pypi.python.org/pypi/neovim/json')
+  if !empty(pypi_info)
+    let pypi_data = json_decode(pypi_info)
+    let s:pypi_version = get(get(pypi_data, 'info', {}), 'version', 'unknown')
+    return s:pypi_version
+  endif
+endfunction
+
+
+" Get version information using the specified interpreter.  The interpreter is
+" used directly in case breaking changes were introduced since the last time
+" Neovim's Python client was updated.
+function! s:version_info(python) abort
+  let pypi_version = s:latest_pypi_version()
+  let python_version = s:trim(system(
+        \ printf('"%s" -c "import sys; print(''.''.join(str(x) '
+        \ . 'for x in sys.version_info[:3]))"', a:python)))
+  if empty(python_version)
+    let python_version = 'unknown'
+  endif
+  
+  let nvim_path = s:trim(system(printf('"%s" -c "import sys, neovim;'
+        \ . 'print(neovim.__file__)" 2>/dev/null', a:python)))
+  if empty(nvim_path)
+    return [python_version, 'not found', pypi_version, 'unknown']
+  endif
+
+  let nvim_version = 'unknown'
+  let base = fnamemodify(nvim_path, ':h')
+  for meta in glob(base.'-*/METADATA', 1, 1) + glob(base.'-*/PKG-INFO', 1, 1)
+    for meta_line in readfile(meta)
+      if meta_line =~# '^Version:'
+        let nvim_version = matchstr(meta_line, '^Version: \zs\S\+')
+      endif
+    endfor
+  endfor
+
+  let version_status = 'unknown'
+  if nvim_version != 'unknown' && pypi_version != 'unknown'
+    if s:version_cmp(nvim_version, pypi_version) == -1
+      let version_status = 'outdated'
+    else
+      let version_status = 'up to date'
+    endif
+  endif
+
+  return [python_version, nvim_version, pypi_version, version_status]
+endfunction
+
+
+" Check the Python interpreter's usability.
+function! s:check_bin(bin, notes) abort
+  if !filereadable(a:bin)
+    call add(a:notes, printf('Error: "%s" was not found.', a:bin))
+    return 0
+  elseif executable(a:bin) != 1
+    call add(a:notes, printf('Error: "%s" is not executable.', a:bin))
+    return 0
+  endif
+  return 1
+endfunction
+
+
+" Text wrapping that returns a list of lines
+function! s:textwrap(text, width) abort
+  let pattern = '.*\%(\s\+\|\_$\)\zs\%<'.a:width.'c'
+  return map(split(a:text, pattern), 's:trim(v:val)')
+endfunction
+
+
+" Echo wrapped notes
+function! s:echo_notes(notes) abort
+  if empty(a:notes)
+    return
+  endif
+
+  echo '  Messages:'
+  for msg in a:notes
+    if msg =~# "\n"
+      let msg_lines = []
+      for msgl in filter(split(msg, "\n"), 'v:val !~# ''^\s*$''')
+        call extend(msg_lines, s:textwrap(msgl, 74))
+      endfor
+    else
+      let msg_lines = s:textwrap(msg, 74)
+    endif
+
+    if !len(msg_lines)
+      continue
+    endif
+    echo '    *' msg_lines[0]
+    if len(msg_lines) > 1
+      echo join(map(msg_lines[1:], '"      ".v:val'), "\n")
+    endif
+  endfor
+endfunction
+
+
+" Load the remote plugin manifest file and check for unregistered plugins
+function! s:diagnose_manifest() abort
+  echo 'Checking: Remote Plugins'
+  let existing_rplugins = {}
+
+  for item in remote#host#PluginsForHost('python')
+    let existing_rplugins[item.path] = 'python'
+  endfor
+
+  for item in remote#host#PluginsForHost('python3')
+    let existing_rplugins[item.path] = 'python3'
+  endfor
+
+  let require_update = 0
+  let notes = []
+
+  for path in map(split(&rtp, ','), 'resolve(v:val)')
+    let python_glob = glob(path.'/rplugin/python*', 1, 1)
+    if empty(python_glob)
+      continue
+    endif
+
+    let python_dir = python_glob[0]
+    let python_version = fnamemodify(python_dir, ':t')
+
+    for script in glob(python_dir.'/*.py', 1, 1)
+          \ + glob(python_dir.'/*/__init__.py', 1, 1)
+      let contents = join(readfile(script))
+      if contents =~# '\<\%(from\|import\)\s\+neovim\>'
+        if script =~# '/__init__\.py$'
+          let script = fnamemodify(script, ':h')
+        endif
+
+        if !has_key(existing_rplugins, script)
+          let msg = printf('"%s" is not registered.', fnamemodify(path, ':t'))
+          if python_version == 'pythonx'
+            if !has('python2') && !has('python3')
+              let msg .= ' (python2 and python3 not available)'
+            endif
+          elseif !has(python_version)
+            let msg .= printf(' (%s not available)', python_version)
+          else
+            let require_update = 1
+          endif
+
+          call add(notes, msg)
+        endif
+
+        break
+      endif
+    endfor
+  endfor
+
+  echo '  Status: '
+  if require_update
+    echon 'Out of date'
+    call add(notes, 'Run :UpdateRemotePlugins')
+  else
+    echon 'Up to date'
+  endif
+
+  call s:echo_notes(notes)
+endfunction
+
+
+function! s:diagnose_python(version) abort
+  let python_bin_name = 'python'.(a:version == 2 ? '' : '3')
+  let pyenv = resolve(exepath('pyenv'))
+  let pyenv_root = exists('$PYENV_ROOT') ? resolve($PYENV_ROOT) : ''
+  let venv = exists('$VIRTUAL_ENV') ? resolve($VIRTUAL_ENV) : ''
+  let host_prog_var = python_bin_name.'_host_prog'
+  let host_skip_var = python_bin_name.'_host_skip_check'
+  let python_bin = ''
+  let python_multiple = []
+  let notes = []
+
+  if exists('g:'.host_prog_var)
+    call add(notes, printf('Using: g:%s = "%s"', host_prog_var, get(g:, host_prog_var)))
+  endif
+
+  let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
+  if empty(python_bin_name)
+    call add(notes, 'Warning: No Python interpreter was found with the neovim '
+          \ . 'module.  Using the first available for diagnostics.')
+    if !empty(pythonx_errs)
+      call add(notes, pythonx_errs)
+    endif
+    let old_skip = get(g:, host_skip_var, 0)
+    let g:[host_skip_var] = 1
+    let [python_bin_name, pythonx_errs] = provider#pythonx#Detect(a:version)
+    let g:[host_skip_var] = old_skip
+  endif
+
+  if !empty(python_bin_name)
+    if exists('g:'.host_prog_var)
+      let python_bin = exepath(python_bin_name)
+    endif
+    let python_bin_name = fnamemodify(python_bin_name, ':t')
+  endif
+
+  if !empty(pythonx_errs)
+    call add(notes, pythonx_errs)
+  endif
+
+  if !empty(python_bin_name) && empty(python_bin) && empty(pythonx_errs)
+    if !exists('g:'.host_prog_var)
+      call add(notes, printf('Warning: "g:%s" is not set.  Searching for '
+            \ . '%s in the environment.', host_prog_var, python_bin_name))
+    endif
+
+    if !empty(pyenv)
+      if empty(pyenv_root)
+        call add(notes, 'Warning: pyenv was found, but $PYENV_ROOT '
+              \ . 'is not set.  Did you follow the final install '
+              \ . 'instructions?')
+      else
+        call add(notes, printf('Notice: pyenv found: "%s"', pyenv))
+      endif
+
+      let python_bin = s:trim(system(
+            \ printf('"%s" which %s 2>/dev/null', pyenv, python_bin_name)))
+
+      if empty(python_bin)
+        call add(notes, printf('Warning: pyenv couldn''t find %s.', python_bin_name))
+      endif
+    endif
+
+    if empty(python_bin)
+      let python_bin = exepath(python_bin_name)
+
+      if exists('$PATH')
+        for path in split($PATH, ':')
+          let path_bin = path.'/'.python_bin_name
+          if path_bin != python_bin && index(python_multiple, path_bin) == -1
+                \ && executable(path_bin)
+            call add(python_multiple, path_bin)
+          endif
+        endfor
+
+        if len(python_multiple)
+          " This is worth noting since the user may install something
+          " that changes $PATH, like homebrew.
+          call add(notes, printf('Suggestion: There are multiple %s executables found.  '
+                \ . 'Set "g:%s" to avoid surprises.', python_bin_name, host_prog_var))
+        endif
+
+        if python_bin =~# '\<shims\>'
+          call add(notes, printf('Warning: "%s" appears to be a pyenv shim.  '
+                \ . 'This could mean that a) the "pyenv" executable is not in '
+                \ . '$PATH, b) your pyenv installation is broken.  '
+                \ . 'You should set "g:%s" to avoid surprises.',
+                \ python_bin, host_prog_var))
+        endif
+      endif
+    endif
+  endif
+
+  if !empty(python_bin)
+    if !empty(pyenv) && !exists('g:'.host_prog_var) && !empty(pyenv_root)
+          \ && resolve(python_bin) !~# '^'.pyenv_root.'/'
+      call add(notes, printf('Suggestion: Create a virtualenv specifically '
+            \ . 'for Neovim using pyenv and use "g:%s".  This will avoid '
+            \ . 'the need to install Neovim''s Python client in each '
+            \ . 'version/virtualenv.', host_prog_var))
+    endif
+
+    if !empty(venv) && exists('g:'.host_prog_var)
+      if !empty(pyenv_root)
+        let venv_root = pyenv_root
+      else
+        let venv_root = fnamemodify(venv, ':h')
+      endif
+
+      if resolve(python_bin) !~# '^'.venv_root.'/'
+        call add(notes, printf('Suggestion: Create a virtualenv specifically '
+              \ . 'for Neovim and use "g:%s".  This will avoid '
+              \ . 'the need to install Neovim''s Python client in each '
+              \ . 'virtualenv.', host_prog_var))
+      endif
+    endif
+  endif
+
+  if empty(python_bin) && !empty(python_bin_name)
+    " An error message should have already printed.
+    call add(notes, printf('Error: "%s" was not found.', python_bin_name))
+  elseif !empty(python_bin) && !s:check_bin(python_bin, notes)
+    let python_bin = ''
+  endif
+
+  " Check if $VIRTUAL_ENV is active
+  let virtualenv_inactive = 0
+
+  if exists('$VIRTUAL_ENV')
+    if !empty(pyenv)
+      let pyenv_prefix = resolve(s:trim(system(printf('"%s" prefix', pyenv))))
+      if $VIRTUAL_ENV != pyenv_prefix
+        let virtualenv_inactive = 1
+      endif
+    elseif !empty(python_bin_name) && exepath(python_bin_name) !~# '^'.$VIRTUAL_ENV.'/'
+      let virtualenv_inactive = 1
+    endif
+  endif
+
+  if virtualenv_inactive
+    call add(notes, 'Warning: $VIRTUAL_ENV exists but appears to be '
+          \ . 'inactive.  This could lead to unexpected results.  If you are '
+          \ . 'using Zsh, see: http://vi.stackexchange.com/a/7654/5229')
+  endif
+
+  " Diagnostic output
+  echo 'Checking: Python' a:version
+  echo '  Executable:' (empty(python_bin) ? 'Not found' : python_bin)
+  if len(python_multiple)
+    for path_bin in python_multiple
+      echo '     (other):' path_bin
+    endfor
+  endif
+
+  if !empty(python_bin)
+    let [pyversion, current, latest, status] = s:version_info(python_bin)
+    if a:version != str2nr(pyversion)
+      call add(notes, 'Warning: Got an unexpected version of Python.  '
+            \ . 'This could lead to confusing error messages.  Please '
+            \ . 'consider this before reporting bugs to plugin developers.')
+    endif
+    if a:version == 3 && str2float(pyversion) < 3.3
+      call add(notes, 'Warning: Python 3.3+ is recommended.')
+    endif
+
+    echo '  Python Version:' pyversion
+    echo printf('  %s-neovim Version: %s', python_bin_name, current)
+
+    if current == 'not found'
+      call add(notes, 'Error: Neovim Python client is not installed.')
+    endif
+
+    if latest == 'unknown'
+      call add(notes, 'Warning: Unable to fetch latest Neovim Python client version.')
+    endif
+
+    if status == 'outdated'
+      echon ' (latest: '.latest.')'
+    else
+      echon ' ('.status.')'
+    endif
+  endif
+
+  call s:echo_notes(notes)
+endfunction
+
+
+function! health#check(bang) abort
+  redir => report
+  try
+    silent call s:diagnose_python(2)
+    silent echo ''
+    silent call s:diagnose_python(3)
+    silent echo ''
+    silent call s:diagnose_manifest()
+    silent echo ''
+  finally
+    redir END
+  endtry
+
+  if a:bang
+    new
+    setlocal bufhidden=wipe
+    call setline(1, split(report, "\n"))
+    setlocal nomodified
+  else
+    echo report
+    echo "\nTip: Use "
+    echohl Identifier
+    echon ":CheckHealth!"
+    echohl None
+    echon " to open this in a new buffer."
+  endif
+endfunction
diff --git a/runtime/doc/nvim_python.txt b/runtime/doc/nvim_python.txt
index a2fc968db4..27955a76b1 100644
--- a/runtime/doc/nvim_python.txt
+++ b/runtime/doc/nvim_python.txt
@@ -8,6 +8,7 @@ Python plugins and scripting in Nvim				  *nvim-python*
 
 1. Introduction			|nvim-python-intro|
 2. Quickstart			|nvim-python-quickstart|
+3. Troubleshooting		|nvim-python-troubleshooting|
 
 ==============================================================================
 1. Introduction						    *nvim-python-intro*
@@ -92,4 +93,20 @@ Note: If you disable Python 3 check, you must install neovim module properly.
     let g:python3_host_skip_check = 1
 <
 ==============================================================================
+3. Troubleshooting				  *nvim-python-troubleshooting*
+
+If you are experiencing issues with a plugin that uses the `neovim` Python
+client, you can use the |:CheckHealth| command to quickly rule out your setup
+as a problem.
+
+								 *:CheckHealth*
+:CheckHealth[!]	  Check your setup for common problems that may be keeping a
+		  plugin from functioning correctly.  Including the output of
+		  this command in bug reports can help reduce the amount of
+		  time it takes to address your issue.  If [!] is present, the
+		  output will be placed in a new buffer which can make it
+		  easier to save to a file or copy to the clipboard.
+
+
+==============================================================================
  vim:tw=78:ts=8:noet:ft=help:norl:
diff --git a/runtime/plugin/health.vim b/runtime/plugin/health.vim
new file mode 100644
index 0000000000..db094a03a4
--- /dev/null
+++ b/runtime/plugin/health.vim
@@ -0,0 +1 @@
+command! -bang CheckHealth call health#check(<bang>0)