Move parser status vars to their own struct

Instead of using an enum + array, just use a struct and drop the getter and
setter methods from `parser_t`.

src/builtins/fg.cpp

@@ -110,11 +110,11 @@ maybe_t<int> builtin_fg(parser_t &parser, io_streams_t &streams, const wchar_t *
     wcstring ft = tok_command(job->command());
     if (!ft.empty()) {
         // Provide value for `status current-command`
-        parser.set_status_var(parser_status_var_t::current_command, ft);
+        parser.libdata().status_vars.command = ft;
         // Also provide a value for the deprecated fish 2.0 $_ variable
         parser.set_var_and_fire(L"_", ENV_EXPORT, std::move(ft));
         // Provide value for `status current-commandline`
-        parser.set_status_var(parser_status_var_t::current_commandline, job->command());
+        parser.libdata().status_vars.commandline = job->command();
     }
     reader_write_title(job->command(), parser);
 

src/builtins/status.cpp

@@ -451,7 +451,7 @@ maybe_t<int> builtin_status(parser_t &parser, io_streams_t &streams, const wchar
         }
         case STATUS_CURRENT_CMD: {
             CHECK_FOR_UNEXPECTED_STATUS_ARGS(opts.status_cmd)
-            const auto &var = parser.get_status_var(parser_status_var_t::current_command);
+            const auto &var = parser.libdata().status_vars.command;
             if (!var.empty()) {
                 streams.out.append(var);
                 streams.out.push_back(L'\n');
@@ -463,7 +463,7 @@ maybe_t<int> builtin_status(parser_t &parser, io_streams_t &streams, const wchar
         }
         case STATUS_CURRENT_COMMANDLINE: {
             CHECK_FOR_UNEXPECTED_STATUS_ARGS(opts.status_cmd)
-            const auto &var = parser.get_status_var(parser_status_var_t::current_commandline);
+            const auto &var = parser.libdata().status_vars.commandline;
             streams.out.append(var);
             streams.out.push_back(L'\n');
             break;

src/parser.h

@@ -221,6 +221,15 @@ struct library_data_t {
     /// A file descriptor holding the current working directory, for use in openat().
     /// This is never null and never invalid.
     std::shared_ptr<const autoclose_fd_t> cwd_fd{};
+
+    /// Status variables set by the main thread as jobs are parsed and read by various consumers.
+    struct {
+        /// Used to get the head of the current job (not the current command, at least for now)
+        /// for `status current-command`.
+        wcstring command;
+        /// Used to get the full text of the current job for `status current-commandline`.
+        wcstring commandline;
+    } status_vars;
 };
 
 /// The result of parser_t::eval family.
@@ -270,9 +279,6 @@ class parser_t : public std::enable_shared_from_this<parser_t> {
     /// top down using range-based for loops.
     std::deque<block_t> block_list;
 
-    /// Variables set by the single-threaded parser or reader and queryable by any consumer.
-    std::array<wcstring, (int) parser_status_var_t::count_> status_vars_;
-
     /// The 'depth' of the fish call stack.
     int eval_level = -1;
 
@@ -398,17 +404,6 @@ class parser_t : public std::enable_shared_from_this<parser_t> {
     statuses_t get_last_statuses() const { return vars().get_last_statuses(); }
     void set_last_statuses(statuses_t s) { vars().set_last_statuses(std::move(s)); }
 
-    /// Get a parser status variable
-    const wcstring& get_status_var(parser_status_var_t var) const {
-        return status_vars_.at((int) var);
-    }
-
-    /// Set a parser status variable
-    void set_status_var(parser_status_var_t var, wcstring val) {
-        ASSERT_IS_MAIN_THREAD();
-        status_vars_[(int) var] = std::move(val);
-    }
-
     /// Cover of vars().set(), which also fires any returned event handlers.
     /// \return a value like ENV_OK.
     int set_var_and_fire(const wcstring &key, env_mode_flags_t mode, wcstring val);

src/reader.cpp

@@ -2495,7 +2495,7 @@ static void reader_interactive_init(parser_t &parser) {
     termsize_container_t::shared().invalidate_tty();
 
     // Provide value for `status current-command`
-    parser.set_status_var(parser_status_var_t::current_command, L"fish");
+    parser.libdata().status_vars.command = L"fish";
     // Also provide a value for the deprecated fish 2.0 $_ variable
     parser.vars().set_one(L"_", ENV_GLOBAL, L"fish");
 }
@@ -2632,8 +2632,8 @@ static eval_res_t reader_run_command(parser_t &parser, const wcstring &cmd) {
 
     // Provide values for `status current-command` and `status current-commandline`
     if (!ft.empty()) {
-        parser.set_status_var(parser_status_var_t::current_command, ft);
+        parser.libdata().status_vars.command = ft;
-        parser.set_status_var(parser_status_var_t::current_commandline, cmd);
+        parser.libdata().status_vars.commandline = cmd;
         // Also provide a value for the deprecated fish 2.0 $_ variable
         parser.vars().set_one(L"_", ENV_GLOBAL, ft);
     }
@@ -2647,7 +2647,7 @@ static eval_res_t reader_run_command(parser_t &parser, const wcstring &cmd) {
     auto eval_res = parser.eval(cmd, io_chain_t{});
     job_reap(parser, true);
 
-    // update the execution duration iff a command is requested for execution
+    // Update the execution duration iff a command is requested for execution
     // issue - #4926
     if (!ft.empty()) {
         timepoint_t time_after = timef();
@@ -2659,11 +2659,11 @@ static eval_res_t reader_run_command(parser_t &parser, const wcstring &cmd) {
     term_steal();
 
     // Provide value for `status current-command`
-    parser.set_status_var(parser_status_var_t::current_command, program_name);
+    parser.libdata().status_vars.command = program_name;
     // Also provide a value for the deprecated fish 2.0 $_ variable
     parser.vars().set_one(L"_", ENV_GLOBAL, program_name);
     // Provide value for `status current-commandline`
-    parser.set_status_var(parser_status_var_t::current_commandline, L"");
+    parser.libdata().status_vars.commandline = L"";
 
     if (have_proc_stat()) {
         proc_update_jiffies(parser);