Replace sort_modules_alphabetically boolean with enum

This fixes the long-standing FIXME there and makes the code easier to
understand. The reference to modules in both the old and new names seems
potentially wrong since I believe it applies to all items.

Author: camelid

src/librustdoc/config.rs

@@ -218,12 +218,9 @@ pub(crate) struct RenderOptions {
     ///
     /// Be aware: This option can come both from the CLI and from crate attributes!
     pub(crate) playground_url: Option<String>,
-    /// Whether to sort modules alphabetically on a module page instead of using declaration order.
-    /// `true` by default.
-    //
-    // FIXME(misdreavus): the flag name is `--sort-modules-by-appearance` but the meaning is
-    // inverted once read.
-    pub(crate) sort_modules_alphabetically: bool,
+    /// What sorting mode to use for module pages.
+    /// `ModuleSorting::Alphabetical` by default.
+    pub(crate) module_sorting: ModuleSorting,
     /// List of themes to extend the docs with. Original argument name is included to assist in
     /// displaying errors if it fails a theme check.
     pub(crate) themes: Vec<StylePath>,
@@ -281,6 +278,12 @@ pub(crate) struct RenderOptions {
     pub(crate) no_emit_shared: bool,
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub(crate) enum ModuleSorting {
+    DeclarationOrder,
+    Alphabetical,
+}
+
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub(crate) enum EmitType {
     Unversioned,
@@ -650,7 +653,11 @@ impl Options {
         let proc_macro_crate = crate_types.contains(&CrateType::ProcMacro);
         let playground_url = matches.opt_str("playground-url");
         let maybe_sysroot = matches.opt_str("sysroot").map(PathBuf::from);
-        let sort_modules_alphabetically = !matches.opt_present("sort-modules-by-appearance");
+        let module_sorting = if matches.opt_present("sort-modules-by-appearance") {
+            ModuleSorting::DeclarationOrder
+        } else {
+            ModuleSorting::Alphabetical
+        };
         let resource_suffix = matches.opt_str("resource-suffix").unwrap_or_default();
         let enable_minification = !matches.opt_present("disable-minification");
         let markdown_no_toc = matches.opt_present("markdown-no-toc");
@@ -731,7 +738,7 @@ impl Options {
                 external_html,
                 id_map,
                 playground_url,
-                sort_modules_alphabetically,
+                module_sorting,
                 themes,
                 extension_css,
                 extern_html_root_urls,

src/librustdoc/html/render/context.rs

@@ -22,7 +22,7 @@ use super::{
 };
 
 use crate::clean::{self, types::ExternalLocation, ExternalCrate};
-use crate::config::RenderOptions;
+use crate::config::{ModuleSorting, RenderOptions};
 use crate::docfs::{DocFS, PathError};
 use crate::error::Error;
 use crate::formats::cache::Cache;
@@ -95,7 +95,7 @@ pub(crate) struct SharedContext<'tcx> {
     created_dirs: RefCell<FxHashSet<PathBuf>>,
     /// This flag indicates whether listings of modules (in the side bar and documentation itself)
     /// should be ordered alphabetically or in order of appearance (in the source code).
-    pub(super) sort_modules_alphabetically: bool,
+    pub(super) module_sorting: ModuleSorting,
     /// Additional CSS files to be added to the generated docs.
     pub(crate) style_files: Vec<StylePath>,
     /// Suffix to be added on resource files (if suffix is "-v2" then "light.css" becomes
@@ -280,10 +280,13 @@ impl<'tcx> Context<'tcx> {
             }
         }
 
-        if self.shared.sort_modules_alphabetically {
-            for items in map.values_mut() {
-                items.sort();
+        match self.shared.module_sorting {
+            ModuleSorting::Alphabetical => {
+                for items in map.values_mut() {
+                    items.sort();
+                }
             }
+            ModuleSorting::DeclarationOrder => {}
         }
         map
     }
@@ -394,7 +397,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             external_html,
             id_map,
             playground_url,
-            sort_modules_alphabetically,
+            module_sorting,
             themes: style_files,
             default_settings,
             extension_css,
@@ -476,7 +479,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             issue_tracker_base_url,
             layout,
             created_dirs: Default::default(),
-            sort_modules_alphabetically,
+            module_sorting,
             style_files,
             resource_suffix,
             static_root_path,

src/librustdoc/html/render/print_item.rs

@@ -23,6 +23,7 @@ use super::{
     AssocItemLink, Context, ImplRenderingParameters,
 };
 use crate::clean;
+use crate::config::ModuleSorting;
 use crate::formats::item_type::ItemType;
 use crate::formats::{AssocItemRender, Impl, RenderMode};
 use crate::html::escape::Escape;
@@ -246,8 +247,11 @@ fn item_module(w: &mut Buffer, cx: &mut Context<'_>, item: &clean::Item, items:
         compare_names(lhs.as_str(), rhs.as_str())
     }
 
-    if cx.shared.sort_modules_alphabetically {
-        indices.sort_by(|&i1, &i2| cmp(&items[i1], &items[i2], i1, i2, cx.tcx()));
+    match cx.shared.module_sorting {
+        ModuleSorting::Alphabetical => {
+            indices.sort_by(|&i1, &i2| cmp(&items[i1], &items[i2], i1, i2, cx.tcx()));
+        }
+        ModuleSorting::DeclarationOrder => {}
     }
     // This call is to remove re-export duplicates in cases such as:
     //