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

1 files changed, 20 insertions, 22 deletions

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);
 }