1 files changed, 128 insertions, 0 deletions
diff --git a/src/nvim/lua/vim.lua b/src/nvim/lua/vim.lua
new file mode 100644
index 0000000000..e1bbb03d3f
--- /dev/null
+++ b/src/nvim/lua/vim.lua
@@ -0,0 +1,128 @@
+-- Internal-only until comments in #8107 are addressed.
+-- Returns:
+--    {errcode}, {output}
+local function _system(cmd)
+  local out = vim.api.nvim_call_function('system', { cmd })
+  local err = vim.api.nvim_get_vvar('shell_error')
+  return err, out
+end
+
+-- Gets process info from the `ps` command.
+-- Used by nvim_get_proc() as a fallback.
+local function _os_proc_info(pid)
+  if pid == nil or pid <= 0 or type(pid) ~= 'number' then
+    error('invalid pid')
+  end
+  local cmd = { 'ps', '-p', pid, '-o', 'ucomm=', }
+  local err, name = _system(cmd)
+  if 1 == err and string.gsub(name, '%s*', '') == '' then
+    return {}  -- Process not found.
+  elseif 0 ~= err then
+    local args_str = vim.api.nvim_call_function('string', { cmd })
+    error('command failed: '..args_str)
+  end
+  local _, ppid = _system({ 'ps', '-p', pid, '-o', 'ppid=', })
+  -- Remove trailing whitespace.
+  name = string.gsub(name, '%s+$', '')
+  ppid = string.gsub(ppid, '%s+$', '')
+  ppid = tonumber(ppid) == nil and -1 or tonumber(ppid)
+  return {
+    name = name,
+    pid = pid,
+    ppid = ppid,
+  }
+end
+
+-- Gets process children from the `pgrep` command.
+-- Used by nvim_get_proc_children() as a fallback.
+local function _os_proc_children(ppid)
+  if ppid == nil or ppid <= 0 or type(ppid) ~= 'number' then
+    error('invalid ppid')
+  end
+  local cmd = { 'pgrep', '-P', ppid, }
+  local err, rv = _system(cmd)
+  if 1 == err and string.gsub(rv, '%s*', '') == '' then
+    return {}  -- Process not found.
+  elseif 0 ~= err then
+    local args_str = vim.api.nvim_call_function('string', { cmd })
+    error('command failed: '..args_str)
+  end
+  local children = {}
+  for s in string.gmatch(rv, '%S+') do
+    local i = tonumber(s)
+    if i ~= nil then
+      table.insert(children, i)
+    end
+  end
+  return children
+end
+
+-- TODO(ZyX-I): Create compatibility layer.
+--{{{1 package.path updater function
+-- Last inserted paths. Used to clear out items from package.[c]path when they
+-- are no longer in &runtimepath.
+local last_nvim_paths = {}
+local function _update_package_paths()
+  local cur_nvim_paths = {}
+  local rtps = vim.api.nvim_list_runtime_paths()
+  local sep = package.config:sub(1, 1)
+  for _, key in ipairs({'path', 'cpath'}) do
+    local orig_str = package[key] .. ';'
+    local pathtrails_ordered = {}
+    local orig = {}
+    -- Note: ignores trailing item without trailing `;`. Not using something
+    -- simpler in order to preserve empty items (stand for default path).
+    for s in orig_str:gmatch('[^;]*;') do
+      s = s:sub(1, -2)  -- Strip trailing semicolon
+      orig[#orig + 1] = s
+    end
+    if key == 'path' then
+      -- /?.lua and /?/init.lua
+      pathtrails_ordered = {sep .. '?.lua', sep .. '?' .. sep .. 'init.lua'}
+    else
+      local pathtrails = {}
+      for _, s in ipairs(orig) do
+        -- Find out path patterns. pathtrail should contain something like
+        -- /?.so, \?.dll. This allows not to bother determining what correct
+        -- suffixes are.
+        local pathtrail = s:match('[/\\][^/\\]*%?.*$')
+        if pathtrail and not pathtrails[pathtrail] then
+          pathtrails[pathtrail] = true
+          pathtrails_ordered[#pathtrails_ordered + 1] = pathtrail
+        end
+      end
+    end
+    local new = {}
+    for _, rtp in ipairs(rtps) do
+      if not rtp:match(';') then
+        for _, pathtrail in pairs(pathtrails_ordered) do
+          local new_path = rtp .. sep .. 'lua' .. pathtrail
+          -- Always keep paths from &runtimepath at the start:
+          -- append them here disregarding orig possibly containing one of them.
+          new[#new + 1] = new_path
+          cur_nvim_paths[new_path] = true
+        end
+      end
+    end
+    for _, orig_path in ipairs(orig) do
+      -- Handle removing obsolete paths originating from &runtimepath: such
+      -- paths either belong to cur_nvim_paths and were already added above or
+      -- to last_nvim_paths and should not be added at all if corresponding
+      -- entry was removed from &runtimepath list.
+      if not (cur_nvim_paths[orig_path] or last_nvim_paths[orig_path]) then
+        new[#new + 1] = orig_path
+      end
+    end
+    package[key] = table.concat(new, ';')
+  end
+  last_nvim_paths = cur_nvim_paths
+end
+
+local module = {
+  _update_package_paths = _update_package_paths,
+  _os_proc_children = _os_proc_children,
+  _os_proc_info = _os_proc_info,
+  _system = _system,
+}
+
+return module