refactor(options): remove `.indir`, redesign option scopes #31066

Problem:
The way option scopes currently work is inflexible and does not allow for nested
option scopes or easily finding the value of an option at any arbitrary scope
without having to do long handwritten switch-case statements like in
`get_varp()`. `.indir` is also confusing and redundant since option indices for
each scope can be autogenerated.

Solution:
Expand option scopes in such a way that an option can support any amount of
scopes using a set of scope flags, similarly to how it's already done for option
types. Also make options contain information about its index at each scope it
supports. This allows for massively simplifying `get_varp()` and
`get_varp_scope()` in the future by just using a struct for options at each
scope. This would be done by creating a table that stores the offset of an
option's variable at a scope by using the option's index at that scope as a key.
This PR also autogenerates enums for option indices at each scope to remove the
need for `.indir` entirely, and also to allow easily iterating over options all
options that support any scope.

Ref: #29314

19 files changed, 795 insertions, 887 deletions

diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index cb71144130..344b4bef00 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -308,7 +308,6 @@ set(GENERATOR_C_GRAMMAR ${GENERATOR_DIR}/c_grammar.lua)
 set(GENERATOR_HASHY ${GENERATOR_DIR}/hashy.lua)
 set(GENERATOR_PRELOAD ${GENERATOR_DIR}/preload.lua)
 set(HEADER_GENERATOR ${GENERATOR_DIR}/gen_declarations.lua)
-set(OPTIONS_ENUM_GENERATOR ${GENERATOR_DIR}/gen_options_enum.lua)
 set(OPTIONS_GENERATOR ${GENERATOR_DIR}/gen_options.lua)
 
 # GENERATED_DIR and GENERATED_INCLUDES_DIR
@@ -687,16 +686,11 @@ add_custom_command(OUTPUT ${GENERATED_EVENTS_ENUM} ${GENERATED_EVENTS_NAMES_MAP}
   DEPENDS ${LUA_GEN_DEPS} ${EVENTS_GENERATOR} ${CMAKE_CURRENT_LIST_DIR}/auevents.lua
 )
 
-add_custom_command(OUTPUT ${GENERATED_OPTIONS}
-  COMMAND ${LUA_GEN} ${OPTIONS_GENERATOR} ${GENERATED_OPTIONS}
+add_custom_command(OUTPUT ${GENERATED_OPTIONS} ${GENERATED_OPTIONS_ENUM} ${GENERATED_OPTIONS_MAP}
+  COMMAND ${LUA_GEN} ${OPTIONS_GENERATOR} ${GENERATED_OPTIONS} ${GENERATED_OPTIONS_ENUM} ${GENERATED_OPTIONS_MAP}
   DEPENDS ${LUA_GEN_DEPS} ${OPTIONS_GENERATOR} ${CMAKE_CURRENT_LIST_DIR}/options.lua
 )
 
-add_custom_command(OUTPUT ${GENERATED_OPTIONS_ENUM} ${GENERATED_OPTIONS_MAP}
-  COMMAND ${LUA_GEN} ${OPTIONS_ENUM_GENERATOR} ${GENERATED_OPTIONS_ENUM} ${GENERATED_OPTIONS_MAP}
-  DEPENDS ${LUA_GEN_DEPS} ${OPTIONS_ENUM_GENERATOR} ${CMAKE_CURRENT_LIST_DIR}/options.lua
-)
-
 # NVIM_GENERATED_FOR_SOURCES and NVIM_GENERATED_FOR_HEADERS must be mutually exclusive.
 foreach(hfile ${NVIM_GENERATED_FOR_HEADERS})
   list(FIND NVIM_GENERATED_FOR_SOURCES ${hfile} hfile_idx)
diff --git a/src/nvim/api/deprecated.c b/src/nvim/api/deprecated.c
index b3ba832fec..b38a7d4173 100644
--- a/src/nvim/api/deprecated.c
+++ b/src/nvim/api/deprecated.c
@@ -533,7 +533,7 @@ void nvim_set_option(uint64_t channel_id, String name, Object value, Error *err)
   FUNC_API_SINCE(1)
   FUNC_API_DEPRECATED_SINCE(11)
 {
-  set_option_to(channel_id, NULL, kOptReqGlobal, name, value, err);
+  set_option_to(channel_id, NULL, kOptScopeGlobal, name, value, err);
 }
 
 /// Gets the global value of an option.
@@ -546,7 +546,7 @@ Object nvim_get_option(String name, Error *err)
   FUNC_API_SINCE(1)
   FUNC_API_DEPRECATED_SINCE(11)
 {
-  return get_option_from(NULL, kOptReqGlobal, name, err);
+  return get_option_from(NULL, kOptScopeGlobal, name, err);
 }
 
 /// Gets a buffer option value
@@ -566,7 +566,7 @@ Object nvim_buf_get_option(Buffer buffer, String name, Error *err)
     return (Object)OBJECT_INIT;
   }
 
-  return get_option_from(buf, kOptReqBuf, name, err);
+  return get_option_from(buf, kOptScopeBuf, name, err);
 }
 
 /// Sets a buffer option value. Passing `nil` as value deletes the option (only
@@ -588,7 +588,7 @@ void nvim_buf_set_option(uint64_t channel_id, Buffer buffer, String name, Object
     return;
   }
 
-  set_option_to(channel_id, buf, kOptReqBuf, name, value, err);
+  set_option_to(channel_id, buf, kOptScopeBuf, name, value, err);
 }
 
 /// Gets a window option value
@@ -608,7 +608,7 @@ Object nvim_win_get_option(Window window, String name, Error *err)
     return (Object)OBJECT_INIT;
   }
 
-  return get_option_from(win, kOptReqWin, name, err);
+  return get_option_from(win, kOptScopeWin, name, err);
 }
 
 /// Sets a window option value. Passing `nil` as value deletes the option (only
@@ -630,48 +630,18 @@ void nvim_win_set_option(uint64_t channel_id, Window window, String name, Object
     return;
   }
 
-  set_option_to(channel_id, win, kOptReqWin, name, value, err);
-}
-
-/// Check if option has a value in the requested scope.
-///
-/// @param  opt_idx    Option index in options[] table.
-/// @param  req_scope  Requested option scope. See OptReqScope in option.h.
-///
-/// @return  true if option has a value in the requested scope, false otherwise.
-static bool option_has_scope(OptIndex opt_idx, OptReqScope req_scope)
-{
-  if (opt_idx == kOptInvalid) {
-    return false;
-  }
-
-  vimoption_T *opt = get_option(opt_idx);
-
-  // TTY option.
-  if (is_tty_option(opt->fullname)) {
-    return req_scope == kOptReqGlobal;
-  }
-
-  switch (req_scope) {
-  case kOptReqGlobal:
-    return opt->var != VAR_WIN;
-  case kOptReqBuf:
-    return opt->indir & PV_BUF;
-  case kOptReqWin:
-    return opt->indir & PV_WIN;
-  }
-  UNREACHABLE;
+  set_option_to(channel_id, win, kOptScopeWin, name, value, err);
 }
 
 /// Gets the value of a global or local (buffer, window) option.
 ///
 /// @param[in]   from       Pointer to buffer or window for local option value.
-/// @param       req_scope  Requested option scope. See OptReqScope in option.h.
+/// @param       req_scope  Requested option scope. See OptScope in option.h.
 /// @param       name       The option name.
 /// @param[out]  err        Details of an error that may have occurred.
 ///
 /// @return  the option value.
-static Object get_option_from(void *from, OptReqScope req_scope, String name, Error *err)
+static Object get_option_from(void *from, OptScope req_scope, String name, Error *err)
 {
   VALIDATE_S(name.size > 0, "option name", "<empty>", {
     return (Object)OBJECT_INIT;
@@ -681,7 +651,7 @@ static Object get_option_from(void *from, OptReqScope req_scope, String name, Er
   OptVal value = NIL_OPTVAL;
 
   if (option_has_scope(opt_idx, req_scope)) {
-    value = get_option_value_for(opt_idx, req_scope == kOptReqGlobal ? OPT_GLOBAL : OPT_LOCAL,
+    value = get_option_value_for(opt_idx, req_scope == kOptScopeGlobal ? OPT_GLOBAL : OPT_LOCAL,
                                  req_scope, from, err);
     if (ERROR_SET(err)) {
       return (Object)OBJECT_INIT;
@@ -698,11 +668,11 @@ static Object get_option_from(void *from, OptReqScope req_scope, String name, Er
 /// Sets the value of a global or local (buffer, window) option.
 ///
 /// @param[in]   to         Pointer to buffer or window for local option value.
-/// @param       req_scope  Requested option scope. See OptReqScope in option.h.
+/// @param       req_scope  Requested option scope. See OptScope in option.h.
 /// @param       name       The option name.
 /// @param       value      New option value.
 /// @param[out]  err        Details of an error that may have occurred.
-static void set_option_to(uint64_t channel_id, void *to, OptReqScope req_scope, String name,
+static void set_option_to(uint64_t channel_id, void *to, OptScope req_scope, String name,
                           Object value, Error *err)
 {
   VALIDATE_S(name.size > 0, "option name", "<empty>", {
@@ -725,12 +695,12 @@ static void set_option_to(uint64_t channel_id, void *to, OptReqScope req_scope,
     return;
   });
 
-  int attrs = get_option_attrs(opt_idx);
   // For global-win-local options -> setlocal
   // For        win-local options -> setglobal and setlocal (opt_flags == 0)
-  const int opt_flags = (req_scope == kOptReqWin && !(attrs & SOPT_GLOBAL))
-                        ? 0
-                        : (req_scope == kOptReqGlobal) ? OPT_GLOBAL : OPT_LOCAL;
+  const int opt_flags
+    = (req_scope == kOptScopeWin && !option_has_scope(opt_idx, kOptScopeGlobal))
+      ? 0
+      : ((req_scope == kOptScopeGlobal) ? OPT_GLOBAL : OPT_LOCAL);
 
   WITH_SCRIPT_CONTEXT(channel_id, {
     set_option_value_for(name.data, opt_idx, optval, opt_flags, req_scope, to, err);
diff --git a/src/nvim/api/options.c b/src/nvim/api/options.c
index 96866d80ba..bbfd00f2ea 100644
--- a/src/nvim/api/options.c
+++ b/src/nvim/api/options.c
@@ -23,8 +23,8 @@
 #endif
 
 static int validate_option_value_args(Dict(option) *opts, char *name, OptIndex *opt_idxp,
-                                      int *scope, OptReqScope *req_scope, void **from,
-                                      char **filetype, Error *err)
+                                      int *scope, OptScope *req_scope, void **from, char **filetype,
+                                      Error *err)
 {
 #define HAS_KEY_X(d, v) HAS_KEY(d, option, v)
   if (HAS_KEY_X(opts, scope)) {
@@ -39,14 +39,14 @@ static int validate_option_value_args(Dict(option) *opts, char *name, OptIndex *
     }
   }
 
-  *req_scope = kOptReqGlobal;
+  *req_scope = kOptScopeGlobal;
 
   if (filetype != NULL && HAS_KEY_X(opts, filetype)) {
     *filetype = opts->filetype.data;
   }
 
   if (HAS_KEY_X(opts, win)) {
-    *req_scope = kOptReqWin;
+    *req_scope = kOptScopeWin;
     *from = find_window_by_handle(opts->win, err);
     if (ERROR_SET(err)) {
       return FAIL;
@@ -59,7 +59,7 @@ static int validate_option_value_args(Dict(option) *opts, char *name, OptIndex *
       return FAIL;
     });
     *scope = OPT_LOCAL;
-    *req_scope = kOptReqBuf;
+    *req_scope = kOptScopeBuf;
     *from = find_buffer_by_handle(opts->buf, err);
     if (ERROR_SET(err)) {
       return FAIL;
@@ -78,18 +78,17 @@ static int validate_option_value_args(Dict(option) *opts, char *name, OptIndex *
   });
 
   *opt_idxp = find_option(name);
-  int flags = get_option_attrs(*opt_idxp);
-  if (flags == 0) {
+  if (*opt_idxp == kOptInvalid) {
     // unknown option
     api_set_error(err, kErrorTypeValidation, "Unknown option '%s'", name);
-  } else if (*req_scope == kOptReqBuf || *req_scope == kOptReqWin) {
+  } else if (*req_scope == kOptScopeBuf || *req_scope == kOptScopeWin) {
     // if 'buf' or 'win' is passed, make sure the option supports it
-    int req_flags = *req_scope == kOptReqBuf ? SOPT_BUF : SOPT_WIN;
-    if (!(flags & req_flags)) {
-      char *tgt = *req_scope & kOptReqBuf ? "buf" : "win";
-      char *global = flags & SOPT_GLOBAL ? "global " : "";
-      char *req = flags & SOPT_BUF ? "buffer-local "
-                                   : flags & SOPT_WIN ? "window-local " : "";
+    if (!option_has_scope(*opt_idxp, *req_scope)) {
+      char *tgt = *req_scope == kOptScopeBuf ? "buf" : "win";
+      char *global = option_has_scope(*opt_idxp, kOptScopeGlobal) ? "global " : "";
+      char *req = option_has_scope(*opt_idxp, kOptScopeBuf)
+                  ? "buffer-local "
+                  : (option_has_scope(*opt_idxp, kOptScopeWin) ? "window-local " : "");
 
       api_set_error(err, kErrorTypeValidation, "'%s' cannot be passed for %s%soption '%s'",
                     tgt, global, req, name);
@@ -153,7 +152,7 @@ Object nvim_get_option_value(String name, Dict(option) *opts, Error *err)
 {
   OptIndex opt_idx = 0;
   int scope = 0;
-  OptReqScope req_scope = kOptReqGlobal;
+  OptScope req_scope = kOptScopeGlobal;
   void *from = NULL;
   char *filetype = NULL;
 
@@ -218,7 +217,7 @@ void nvim_set_option_value(uint64_t channel_id, String name, Object value, Dict(
 {
   OptIndex opt_idx = 0;
   int scope = 0;
-  OptReqScope req_scope = kOptReqGlobal;
+  OptScope req_scope = kOptScopeGlobal;
   void *to = NULL;
   if (!validate_option_value_args(opts, name.data, &opt_idx, &scope, &req_scope, &to, NULL, err)) {
     return;
@@ -230,9 +229,8 @@ void nvim_set_option_value(uint64_t channel_id, String name, Object value, Dict(
   // - option is global or local to window (global-local)
   //
   // Then force scope to local since we don't want to change the global option
-  if (req_scope == kOptReqWin && scope == 0) {
-    int flags = get_option_attrs(opt_idx);
-    if (flags & SOPT_GLOBAL) {
+  if (req_scope == kOptScopeWin && scope == 0) {
+    if (option_has_scope(opt_idx, kOptScopeGlobal)) {
       scope = OPT_LOCAL;
     }
   }
@@ -305,15 +303,15 @@ Dict nvim_get_option_info2(String name, Dict(option) *opts, Arena *arena, Error
 {
   OptIndex opt_idx = 0;
   int scope = 0;
-  OptReqScope req_scope = kOptReqGlobal;
+  OptScope req_scope = kOptScopeGlobal;
   void *from = NULL;
   if (!validate_option_value_args(opts, name.data, &opt_idx, &scope, &req_scope, &from, NULL,
                                   err)) {
     return (Dict)ARRAY_DICT_INIT;
   }
 
-  buf_T *buf = (req_scope == kOptReqBuf) ? (buf_T *)from : curbuf;
-  win_T *win = (req_scope == kOptReqWin) ? (win_T *)from : curwin;
+  buf_T *buf = (req_scope == kOptScopeBuf) ? (buf_T *)from : curbuf;
+  win_T *win = (req_scope == kOptScopeWin) ? (win_T *)from : curwin;
 
   return get_vimoption(name, scope, buf, win, arena, err);
 }
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index e6ec88c5e8..199b9a9690 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -1004,10 +1004,10 @@ Buffer nvim_create_buf(Boolean listed, Boolean scratch, Error *err)
   buf_copy_options(buf, BCO_ENTER | BCO_NOHELP);
 
   if (scratch) {
-    set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL, 0, kOptReqBuf,
-                          buf);
-    set_option_direct_for(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"), OPT_LOCAL, 0, kOptReqBuf,
-                          buf);
+    set_option_direct_for(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL, 0,
+                          kOptScopeBuf, buf);
+    set_option_direct_for(kOptBuftype, STATIC_CSTR_AS_OPTVAL("nofile"), OPT_LOCAL, 0,
+                          kOptScopeBuf, buf);
     assert(buf->b_ml.ml_mfp->mf_fd < 0);  // ml_open() should not have opened swapfile already
     buf->b_p_swf = false;
     buf->b_p_ml = false;
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index e6bd63f4f8..d33734ccfe 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -206,7 +206,7 @@ typedef struct {
   OptInt wo_winbl;
 #define w_p_winbl w_onebuf_opt.wo_winbl  // 'winblend'
 
-  LastSet wo_script_ctx[WV_COUNT];        // SCTXs for window-local options
+  LastSet wo_script_ctx[kWinOptCount];  // SCTXs for window-local options
 #define w_p_script_ctx w_onebuf_opt.wo_script_ctx
 } winopt_T;
 
@@ -512,7 +512,7 @@ struct file_buffer {
   // or contents of the file being edited.
   bool b_p_initialized;                 // set when options initialized
 
-  LastSet b_p_script_ctx[BV_COUNT];     // SCTXs for buffer-local options
+  LastSet b_p_script_ctx[kBufOptCount];  // SCTXs for buffer-local options
 
   int b_p_ai;                   ///< 'autoindent'
   int b_p_ai_nopaste;           ///< b_p_ai saved for paste mode
diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index a690c70875..f1dd08f0e6 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -1390,8 +1390,8 @@ void diff_win_options(win_T *wp, bool addbuf)
     }
     wp->w_p_fdm_save = xstrdup(wp->w_p_fdm);
   }
-  set_option_direct_for(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("diff"), OPT_LOCAL, 0, kOptReqWin,
-                        wp);
+  set_option_direct_for(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("diff"), OPT_LOCAL, 0,
+                        kOptScopeWin, wp);
 
   if (!wp->w_p_diff) {
     wp->w_p_fen_save = wp->w_p_fen;
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 9acbc05fdf..ab6115f145 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -1368,7 +1368,7 @@ int eval_foldexpr(win_T *wp, int *cp)
   const bool use_sandbox = was_set_insecurely(wp, kOptFoldexpr, OPT_LOCAL);
 
   char *arg = skipwhite(wp->w_p_fde);
-  current_sctx = wp->w_p_script_ctx[WV_FDE].script_ctx;
+  current_sctx = wp->w_p_script_ctx[kWinOptFoldexpr].script_ctx;
 
   emsg_off++;
   if (use_sandbox) {
diff --git a/src/nvim/file_search.c b/src/nvim/file_search.c
index aeaf448a05..d183978d2d 100644
--- a/src/nvim/file_search.c
+++ b/src/nvim/file_search.c
@@ -1648,7 +1648,7 @@ static char *eval_includeexpr(const char *const ptr, const size_t len)
 {
   const sctx_T save_sctx = current_sctx;
   set_vim_var_string(VV_FNAME, ptr, (ptrdiff_t)len);
-  current_sctx = curbuf->b_p_script_ctx[BV_INEX].script_ctx;
+  current_sctx = curbuf->b_p_script_ctx[kBufOptIncludeexpr].script_ctx;
 
   char *res = eval_to_string_safe(curbuf->b_p_inex,
                                   was_set_insecurely(curwin, kOptIncludeexpr, OPT_LOCAL),
diff --git a/src/nvim/fold.c b/src/nvim/fold.c
index e7231c31ab..c9699cb161 100644
--- a/src/nvim/fold.c
+++ b/src/nvim/fold.c
@@ -1731,7 +1731,7 @@ char *get_foldtext(win_T *wp, linenr_T lnum, linenr_T lnume, foldinfo_T foldinfo
 
       curwin = wp;
       curbuf = wp->w_buffer;
-      current_sctx = wp->w_p_script_ctx[WV_FDT].script_ctx;
+      current_sctx = wp->w_p_script_ctx[kWinOptFoldtext].script_ctx;
 
       emsg_off++;  // handle exceptions, but don't display errors
 
diff --git a/src/nvim/generators/gen_options.lua b/src/nvim/generators/gen_options.lua
index 92349b5298..02f3ac3257 100644
--- a/src/nvim/generators/gen_options.lua
+++ b/src/nvim/generators/gen_options.lua
@@ -1,6 +1,10 @@
 local options_file = arg[1]
+local options_enum_file = arg[2]
+local options_map_file = arg[3]
 
 local opt_fd = assert(io.open(options_file, 'w'))
+local opt_enum_fd = assert(io.open(options_enum_file, 'w'))
+local opt_map_fd = assert(io.open(options_map_file, 'w'))
 
 local w = function(s)
   if s:match('^    %.') then
@@ -10,10 +14,129 @@ local w = function(s)
   end
 end
 
+--- @param s string
+local function enum_w(s)
+  opt_enum_fd:write(s .. '\n')
+end
+
+--- @param s string
+local function map_w(s)
+  opt_map_fd:write(s .. '\n')
+end
+
 --- @module 'nvim.options'
 local options = require('options')
+local options_meta = options.options
 
 local cstr = options.cstr
+local valid_scopes = options.valid_scopes
+
+--- Options for each scope.
+--- @type table<string, vim.option_meta[]>
+local scope_options = {}
+for _, scope in ipairs(valid_scopes) do
+  scope_options[scope] = {}
+end
+
+--- @param s string
+--- @return string
+local lowercase_to_titlecase = function(s)
+  return s:sub(1, 1):upper() .. s:sub(2)
+end
+
+-- Generate options enum file
+enum_w('// IWYU pragma: private, include "nvim/option_defs.h"')
+enum_w('')
+
+--- Map of option name to option index
+--- @type table<string, string>
+local option_index = {}
+
+-- Generate option index enum and populate the `option_index` and `scope_option` dicts.
+enum_w('typedef enum {')
+enum_w('  kOptInvalid = -1,')
+
+for i, o in ipairs(options_meta) do
+  local enum_val_name = 'kOpt' .. lowercase_to_titlecase(o.full_name)
+  enum_w(('  %s = %u,'):format(enum_val_name, i - 1))
+
+  option_index[o.full_name] = enum_val_name
+
+  if o.abbreviation then
+    option_index[o.abbreviation] = enum_val_name
+  end
+
+  if o.alias then
+    o.alias = type(o.alias) == 'string' and { o.alias } or o.alias
+
+    for _, v in ipairs(o.alias) do
+      option_index[v] = enum_val_name
+    end
+  end
+
+  for _, scope in ipairs(o.scope) do
+    table.insert(scope_options[scope], o)
+  end
+end
+
+enum_w('  // Option count')
+enum_w('#define kOptCount ' .. tostring(#options_meta))
+enum_w('} OptIndex;')
+
+--- @param scope string
+--- @param option_name string
+--- @return string
+local get_scope_option = function(scope, option_name)
+  return ('k%sOpt%s'):format(lowercase_to_titlecase(scope), lowercase_to_titlecase(option_name))
+end
+
+-- Generate option index enum for each scope
+for _, scope in ipairs(valid_scopes) do
+  enum_w('')
+
+  local scope_name = lowercase_to_titlecase(scope)
+  enum_w('typedef enum {')
+  enum_w(('  %s = -1,'):format(get_scope_option(scope, 'Invalid')))
+
+  for idx, option in ipairs(scope_options[scope]) do
+    enum_w(('  %s = %u,'):format(get_scope_option(scope, option.full_name), idx - 1))
+  end
+
+  enum_w(('  // %s option count'):format(scope_name))
+  enum_w(('#define %s %d'):format(get_scope_option(scope, 'Count'), #scope_options[scope]))
+  enum_w(('} %sOptIndex;'):format(scope_name))
+end
+
+-- Generate reverse lookup from option scope index to option index for each scope.
+for _, scope in ipairs(valid_scopes) do
+  enum_w('')
+  enum_w(('EXTERN const OptIndex %s_opt_idx[] INIT( = {'):format(scope))
+  for _, option in ipairs(scope_options[scope]) do
+    local idx = option_index[option.full_name]
+    enum_w(('  [%s] = %s,'):format(get_scope_option(scope, option.full_name), idx))
+  end
+  enum_w('});')
+end
+
+opt_enum_fd:close()
+
+-- Generate option index map.
+local hashy = require('generators.hashy')
+local neworder, hashfun = hashy.hashy_hash('find_option', vim.tbl_keys(option_index), function(idx)
+  return ('option_hash_elems[%s].name'):format(idx)
+end)
+
+map_w('static const struct { const char *name; OptIndex opt_idx; } option_hash_elems[] = {')
+
+for _, name in ipairs(neworder) do
+  assert(option_index[name] ~= nil)
+  map_w(('  { .name = "%s", .opt_idx = %s },'):format(name, option_index[name]))
+end
+
+map_w('};\n')
+map_w('static ' .. hashfun)
+
+opt_map_fd:close()
 
 local redraw_flags = {
   ui_option = 'kOptFlagUIOption',
@@ -35,12 +158,6 @@ local list_flags = {
   flagscomma = 'kOptFlagComma|kOptFlagFlagList',
 }
 
---- @param s string
---- @return string
-local lowercase_to_titlecase = function(s)
-  return s:sub(1, 1):upper() .. s:sub(2)
-end
-
 --- @param o vim.option_meta
 --- @return string
 local function get_flags(o)
@@ -95,6 +212,12 @@ local function opt_type_enum(opt_type)
   return ('kOptValType%s'):format(lowercase_to_titlecase(opt_type))
 end
 
+--- @param scope vim.option_scope
+--- @return string
+local function opt_scope_enum(scope)
+  return ('kOptScope%s'):format(lowercase_to_titlecase(scope))
+end
+
 --- @param o vim.option_meta
 --- @return string
 local function get_type_flags(o)
@@ -110,6 +233,35 @@ local function get_type_flags(o)
   return type_flags
 end
 
+--- @param o vim.option_meta
+--- @return string
+local function get_scope_flags(o)
+  local scope_flags = '0'
+
+  for _, scope in ipairs(o.scope) do
+    scope_flags = ('%s | (1 << %s)'):format(scope_flags, opt_scope_enum(scope))
+  end
+
+  return scope_flags
+end
+
+--- @param o vim.option_meta
+--- @return string
+local function get_scope_idx(o)
+  --- @type string[]
+  local strs = {}
+
+  for _, scope in pairs(valid_scopes) do
+    local has_scope = vim.tbl_contains(o.scope, scope)
+    strs[#strs + 1] = ('      [%s] = %s'):format(
+      opt_scope_enum(scope),
+      get_scope_option(scope, has_scope and o.full_name or 'Invalid')
+    )
+  end
+
+  return ('{\n%s\n    }'):format(table.concat(strs, ',\n'))
+end
+
 --- @param c string|string[]
 --- @param base_string? string
 --- @return string
@@ -166,7 +318,6 @@ end
 --- @param d vim.option_value|function
 --- @param n string
 --- @return string
-
 local get_defaults = function(d, n)
   if d == nil then
     error("option '" .. n .. "' should have a default value")
@@ -174,9 +325,6 @@ local get_defaults = function(d, n)
   return get_opt_val(d)
 end
 
---- @type [string,string][]
-local defines = {}
-
 --- @param i integer
 --- @param o vim.option_meta
 local function dump_option(i, o)
@@ -187,42 +335,28 @@ local function dump_option(i, o)
   end
   w('    .flags=' .. get_flags(o))
   w('    .type_flags=' .. get_type_flags(o))
+  w('    .scope_flags=' .. get_scope_flags(o))
+  w('    .scope_idx=' .. get_scope_idx(o))
   if o.enable_if then
     w(get_cond(o.enable_if))
   end
 
-  if o.varname then
-    w('    .var=&' .. o.varname)
-  elseif o.immutable then
-    -- Immutable options can directly point to the default value.
-    w(('    .var=&options[%u].def_val.data'):format(i - 1))
-  elseif #o.scope == 1 and o.scope[1] == 'window' then
-    w('    .var=VAR_WIN')
+  local is_window_local = #o.scope == 1 and o.scope[1] == 'win'
+
+  if not is_window_local then
+    if o.varname then
+      w('    .var=&' .. o.varname)
+    elseif o.immutable then
+      -- Immutable options can directly point to the default value.
+      w(('    .var=&options[%u].def_val.data'):format(i - 1))
+    else
+      -- Option must be immutable or have a variable.
+      assert(false)
+    end
   else
-    -- Option must be immutable or have a variable.
-    assert(false)
+    w('    .var=NULL')
   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
@@ -235,7 +369,6 @@ local function dump_option(i, o)
     w(('    .var=&options[%u].def_val.data'):format(i - 1))
     -- Option is always immutable on the false branch of `enable_if`.
     w('    .immutable=true')
-    w('    .indir=PV_NONE')
     w('#endif')
   end
   if o.defaults then
@@ -256,6 +389,7 @@ local function dump_option(i, o)
   w('  },')
 end
 
+-- Generate options[] array.
 w([[
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_getln.h"
@@ -274,8 +408,3 @@ for i, o in ipairs(options.options) do
   dump_option(i, o)
 end
 w('};')
-w('')
-
-for _, v in ipairs(defines) do
-  w('#define ' .. v[1] .. ' ' .. v[2])
-end
diff --git a/src/nvim/generators/gen_options_enum.lua b/src/nvim/generators/gen_options_enum.lua
deleted file mode 100644
index d1419137d3..0000000000
--- a/src/nvim/generators/gen_options_enum.lua
+++ /dev/null
@@ -1,129 +0,0 @@
--- Generates option index enum and map of option name to option index.
--- Handles option full name, short name and aliases.
--- Also generates BV_ and WV_ enum constants.
-
-local options_enum_file = arg[1]
-local options_map_file = arg[2]
-local options_enum_fd = assert(io.open(options_enum_file, 'w'))
-local options_map_fd = assert(io.open(options_map_file, 'w'))
-
---- @param s string
-local function enum_w(s)
-  options_enum_fd:write(s .. '\n')
-end
-
---- @param s string
-local function map_w(s)
-  options_map_fd:write(s .. '\n')
-end
-
-enum_w('// IWYU pragma: private, include "nvim/option_defs.h"')
-enum_w('')
-
---- @param s string
---- @return string
-local lowercase_to_titlecase = function(s)
-  return s:sub(1, 1):upper() .. s:sub(2)
-end
-
---- @type vim.option_meta[]
-local options = require('options').options
-
--- Generate BV_ enum constants.
-enum_w('/// "indir" values for buffer-local options.')
-enum_w('/// These need to be defined globally, so that the BV_COUNT can be used with')
-enum_w('/// b_p_script_stx[].')
-enum_w('enum {')
-
-local bv_val = 0
-
-for _, o in ipairs(options) do
-  assert(#o.scope == 1 or #o.scope == 2)
-  assert(#o.scope == 1 or o.scope[1] == 'global')
-  local min_scope = o.scope[#o.scope]
-  if min_scope == 'buffer' then
-    local varname = o.pv_name or o.varname or ('p_' .. (o.abbreviation or o.full_name))
-    local bv_name = 'BV_' .. varname:sub(3):upper()
-    enum_w(('  %s = %u,'):format(bv_name, bv_val))
-    bv_val = bv_val + 1
-  end
-end
-
-enum_w(('  BV_COUNT = %u,  ///< must be the last one'):format(bv_val))
-enum_w('};')
-enum_w('')
-
--- Generate WV_ enum constants.
-enum_w('/// "indir" values for window-local options.')
-enum_w('/// These need to be defined globally, so that the WV_COUNT can be used in the')
-enum_w('/// window structure.')
-enum_w('enum {')
-
-local wv_val = 0
-
-for _, o in ipairs(options) do
-  assert(#o.scope == 1 or #o.scope == 2)
-  assert(#o.scope == 1 or o.scope[1] == 'global')
-  local min_scope = o.scope[#o.scope]
-  if min_scope == 'window' then
-    local varname = o.pv_name or o.varname or ('p_' .. (o.abbreviation or o.full_name))
-    local wv_name = 'WV_' .. varname:sub(3):upper()
-    enum_w(('  %s = %u,'):format(wv_name, wv_val))
-    wv_val = wv_val + 1
-  end
-end
-
-enum_w(('  WV_COUNT = %u,  ///< must be the last one'):format(wv_val))
-enum_w('};')
-enum_w('')
-
---- @type { [string]: string }
-local option_index = {}
-
--- Generate option index enum and populate the `option_index` dict.
-enum_w('typedef enum {')
-enum_w('  kOptInvalid = -1,')
-
-for i, o in ipairs(options) do
-  local enum_val_name = 'kOpt' .. lowercase_to_titlecase(o.full_name)
-  enum_w(('  %s = %u,'):format(enum_val_name, i - 1))
-
-  option_index[o.full_name] = enum_val_name
-
-  if o.abbreviation then
-    option_index[o.abbreviation] = enum_val_name
-  end
-
-  if o.alias then
-    o.alias = type(o.alias) == 'string' and { o.alias } or o.alias
-
-    for _, v in ipairs(o.alias) do
-      option_index[v] = enum_val_name
-    end
-  end
-end
-
-enum_w('  // Option count, used when iterating through options')
-enum_w('#define kOptIndexCount ' .. tostring(#options))
-enum_w('} OptIndex;')
-enum_w('')
-
-options_enum_fd:close()
-
---- Generate option index map.
-local hashy = require('generators.hashy')
-local neworder, hashfun = hashy.hashy_hash('find_option', vim.tbl_keys(option_index), function(idx)
-  return ('option_hash_elems[%s].name'):format(idx)
-end)
-
-map_w('static const struct { const char *name; OptIndex opt_idx; } option_hash_elems[] = {')
-
-for _, name in ipairs(neworder) do
-  assert(option_index[name] ~= nil)
-  map_w(('  { .name = "%s", .opt_idx = %s },'):format(name, option_index[name]))
-end
-
-map_w('};\n')
-map_w('static ' .. hashfun)
-
-options_map_fd:close()
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index 58215f738c..e487728901 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -1182,7 +1182,7 @@ int get_expr_i