neovim/src/nvim/generators/gen_options.lua

local options_file = arg[1]
local options_enum_file = arg[2]

local opt_fd = assert(io.open(options_file, 'w'))

local w = function(s)
  if s:match('^    %.') then
    opt_fd:write(s .. ',\n')
  else
    opt_fd:write(s .. '\n')
  end
end

--- @module 'nvim.options'
local options = require('options')

local cstr = options.cstr

local type_flags = {
  bool = 'P_BOOL',
  number = 'P_NUM',
  string = 'P_STRING',
}

local redraw_flags = {
  ui_option = 'P_UI_OPTION',
  tabline = 'P_RTABL',
  statuslines = 'P_RSTAT',
  current_window = 'P_RWIN',
  current_window_only = 'P_RWINONLY',
  current_buffer = 'P_RBUF',
  all_windows = 'P_RALL',
  curswant = 'P_CURSWANT',
}

local list_flags = {
  comma = 'P_COMMA',
  onecomma = 'P_ONECOMMA',
  commacolon = 'P_COMMA|P_COLON',
  onecommacolon = 'P_ONECOMMA|P_COLON',
  flags = 'P_FLAGLIST',
  flagscomma = 'P_COMMA|P_FLAGLIST',
}

--- @param s string
--- @return string
local title_case = function(s)
  return s:sub(1, 1):upper() .. s:sub(2):lower()
end

--- @param o vim.option_meta
--- @return string
local function get_flags(o)
  --- @type string[]
  local ret = { type_flags[o.type] }
  local add_flag = function(f)
    ret[1] = ret[1] .. '|' .. f
  end
  if o.list then
    add_flag(list_flags[o.list])
  end
  if o.redraw then
    for _, r_flag in ipairs(o.redraw) do
      add_flag(redraw_flags[r_flag])
    end
  end
  if o.expand then
    add_flag('P_EXPAND')
    if o.expand == 'nodefault' then
      add_flag('P_NO_DEF_EXP')
    end
  end
  for _, flag_desc in ipairs({
    { 'alloced' },
    { 'nodefault' },
    { 'no_mkrc' },
    { 'secure' },
    { 'gettext' },
    { 'noglob' },
    { 'normal_fname_chars', 'P_NFNAME' },
    { 'normal_dname_chars', 'P_NDNAME' },
    { 'pri_mkrc' },
    { 'deny_in_modelines', 'P_NO_ML' },
    { 'deny_duplicates', 'P_NODUP' },
    { 'modelineexpr', 'P_MLE' },
    { 'func' },
  }) do
    local key_name = flag_desc[1]
    local def_name = flag_desc[2] or ('P_' .. key_name:upper())
    if o[key_name] then
      add_flag(def_name)
    end
  end
  return ret[1]
end

--- @param c string|string[]
--- @param base_string? string
--- @return string
local function get_cond(c, base_string)
  local cond_string = base_string or '#if '
  if type(c) == 'table' then
    cond_string = cond_string .. get_cond(c[1], '')
    for i, subc in ipairs(c) do
      if i > 1 then
        cond_string = cond_string .. ' && ' .. get_cond(subc, '')
      end
    end
  elseif c:sub(1, 1) == '!' then
    cond_string = cond_string .. '!defined(' .. c:sub(2) .. ')'
  else
    cond_string = cond_string .. 'defined(' .. c .. ')'
  end
  return cond_string
end

local value_dumpers = {
  ['function'] = function(v)
    return v()
  end,
  string = cstr,
  boolean = function(v)
    return v and 'true' or 'false'
  end,
  number = function(v)
    return ('%iL'):format(v)
  end,
  ['nil'] = function(_)
    return '0'
  end,
}

local get_value = function(v)
  return '(void *) ' .. value_dumpers[type(v)](v)
end

local get_defaults = function(d, n)
  if d == nil then
    error("option '" .. n .. "' should have a default value")
  end
  return get_value(d)
end

--- @type {[1]:string,[2]:string}[]
local defines = {}

--- @param i integer
--- @param o vim.option_meta
local function dump_option(i, o)
  w('  [' .. ('%u'):format(i - 1) .. ']={')
  w('    .fullname=' .. cstr(o.full_name))
  if o.abbreviation then
    w('    .shortname=' .. cstr(o.abbreviation))
  end
  w('    .flags=' .. get_flags(o))
  if o.enable_if then
    w(get_cond(o.enable_if))
  end
  if o.varname then
    w('    .var=&' .. o.varname)
  -- Immutable options should directly point to the default value
  elseif o.immutable then
    w(('    .var=&options[%u].def_val'):format(i - 1))
  elseif #o.scope == 1 and o.scope[1] == 'window' then
    w('    .var=VAR_WIN')
  end
  w('    .immutable=' .. (o.immutable and 'true' or 'false'))
  if #o.scope == 1 and o.scope[1] == 'global' then
    w('    .indir=PV_NONE')
  else
    assert(#o.scope == 1 or #o.scope == 2)
    assert(#o.scope == 1 or o.scope[1] == 'global')
    local min_scope = o.scope[#o.scope]
    local varname = o.pv_name or o.varname or ('p_' .. (o.abbreviation or o.full_name))
    local pv_name = (
      'OPT_'
      .. min_scope:sub(1, 3):upper()
      .. '('
      .. (min_scope:sub(1, 1):upper() .. 'V_' .. varname:sub(3):upper())
      .. ')'
    )
    if #o.scope == 2 then
      pv_name = 'OPT_BOTH(' .. pv_name .. ')'
    end
    table.insert(defines, { 'PV_' .. varname:sub(3):upper(), pv_name })
    w('    .indir=' .. pv_name)
  end
  if o.cb then
    w('    .opt_did_set_cb=' .. o.cb)
  end
  if o.expand_cb then
    w('    .opt_expand_cb=' .. o.expand_cb)
  end
  if o.enable_if then
    w('#else')
    w('    .var=NULL')
    w('    .indir=PV_NONE')
    w('#endif')
  end
  if o.defaults then
    if o.defaults.condition then
      w(get_cond(o.defaults.condition))
    end
    w('    .def_val=' .. get_defaults(o.defaults.if_true, o.full_name))
    if o.defaults.condition then
      if o.defaults.if_false then
        w('#else')
        w('    .def_val=' .. get_defaults(o.defaults.if_false, o.full_name))
      end
      w('#endif')
    end
  end
  w('  },')
end

w([[
#include "nvim/ex_getln.h"
#include "nvim/insexpand.h"
#include "nvim/mapping.h"
#include "nvim/ops.h"
#include "nvim/option.h"
#include "nvim/optionstr.h"
#include "nvim/quickfix.h"
#include "nvim/runtime.h"
#include "nvim/tag.h"
#include "nvim/window.h"

static vimoption_T options[] = {]])
for i, o in ipairs(options.options) do
  dump_option(i, o)
end
w('  [' .. ('%u'):format(#options.options) .. ']={.fullname=NULL}')
w('};')
w('')

for _, v in ipairs(defines) do
  w('#define ' .. v[1] .. ' ' .. v[2])
end

-- Generate options enum file
opt_fd = assert(io.open(options_enum_file, 'w'))

w('typedef enum {')
for i, o in ipairs(options.options) do
  w(('  kOpt%s = %u,'):format(title_case(o.full_name), i - 1))
end
w('} OptIndex;')

opt_fd:close()