Add new configuration option abort_on_unrecognised_options

This option was proposed in issue 5022

Author: ytmimi

Configurations.md

@@ -17,6 +17,15 @@ To enable unstable options, set `unstable_features = true` in `rustfmt.toml` or
 
 Below you find a detailed visual guide on all the supported configuration options of rustfmt:
 
+## `abort_on_unrecognised_options`
+
+Exit early when using nightly only options on the stable channel
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: #5022)
+
+
 ## `array_width`
 
 Maximum width of an array literal before falling back to vertical formatting.

src/config/mod.rs

@@ -168,6 +168,8 @@ create_config! {
         "Report all, none or unnumbered occurrences of FIXME in source file comments";
     ignore: IgnoreList, IgnoreList::default(), false,
         "Skip formatting the specified files and directories";
+    abort_on_unrecognised_options: bool, false, false,
+        "Exit early when using nightly only options on the stable channel";
 
     // Not user-facing
     verbose: Verbosity, Verbosity::Normal, false, "How much to information to emit to the user";
@@ -625,6 +627,7 @@ error_on_unformatted = false
 report_todo = "Never"
 report_fixme = "Never"
 ignore = []
+abort_on_unrecognised_options = false
 emit_mode = "Files"
 make_backup = false
 "#,