Format inner attributes (#4207)

Author: topecongiro

rustfmt-core/rustfmt-lib/src/formatting.rs

@@ -9,6 +9,7 @@ pub(crate) use syntux::session::ParseSess;
 
 use self::newline_style::apply_newline_style;
 use crate::config::{Config, FileName};
+use crate::formatting::modules::Module;
 use crate::formatting::{
     comment::{CharClasses, FullCodeCharKind},
     report::NonFormattedRange,
@@ -127,14 +128,12 @@ fn format_project(
         should_emit_verbose(input_is_stdin, operation_setting.verbosity, || {
             println!("Formatting {}", path)
         });
-        let is_root = path == main_file;
         format_file(
             &parse_session,
             config,
             &krate,
             path,
             &module,
-            is_root,
             &format_report,
             original_snippet.clone(),
         );
@@ -157,29 +156,17 @@ fn format_file(
     config: &Config,
     krate: &ast::Crate,
     path: FileName,
-    module: &ast::Mod,
-    is_root: bool,
+    module: &Module<'_>,
     report: &FormatReport,
     original_snippet: Option<String>,
 ) {
-    let snippet_provider = parse_session.snippet_provider(module.inner);
+    let snippet_provider = parse_session.snippet_provider(module.as_ref().inner);
     let mut visitor =
         FmtVisitor::from_parse_sess(&parse_session, config, &snippet_provider, report.clone());
     visitor.skip_context.update_with_attrs(&krate.attrs);
-
-    // Format inner attributes if available.
-    if !krate.attrs.is_empty() && is_root {
-        visitor.skip_empty_lines(snippet_provider.end_pos());
-        if visitor.visit_attrs(&krate.attrs, ast::AttrStyle::Inner) {
-            visitor.push_rewrite(module.inner, None);
-        } else {
-            visitor.format_separate_mod(module, snippet_provider.end_pos());
-        }
-    } else {
-        visitor.last_pos = snippet_provider.start_pos();
-        visitor.skip_empty_lines(snippet_provider.end_pos());
-        visitor.format_separate_mod(module, snippet_provider.end_pos());
-    };
+    visitor.last_pos = snippet_provider.start_pos();
+    visitor.skip_empty_lines(snippet_provider.end_pos());
+    visitor.format_separate_mod(module, snippet_provider.end_pos());
 
     debug_assert_eq!(
         visitor.line_number,

rustfmt-core/rustfmt-lib/src/formatting/modules.rs

@@ -3,6 +3,7 @@ use std::collections::BTreeMap;
 use std::path::{Path, PathBuf};
 
 use rustc_ast::ast;
+use rustc_ast::attr::HasAttrs;
 use rustc_ast::visit::Visitor;
 use rustc_span::symbol::{self, sym, Symbol};
 use thiserror::Error;
@@ -18,12 +19,48 @@ use crate::formatting::{
 
 mod visitor;
 
-type FileModMap<'ast> = BTreeMap<FileName, Cow<'ast, ast::Mod>>;
+type FileModMap<'ast> = BTreeMap<FileName, Module<'ast>>;
 
 lazy_static! {
     static ref CFG_IF: Symbol = Symbol::intern("cfg_if");
 }
 
+/// Represents module with its inner attributes.
+#[derive(Debug, Clone)]
+pub(crate) struct Module<'a> {
+    ast_mod: Cow<'a, ast::Mod>,
+    inner_attr: Vec<ast::Attribute>,
+}
+
+impl<'a> Module<'a> {
+    pub(crate) fn new(ast_mod: Cow<'a, ast::Mod>, attrs: &[ast::Attribute]) -> Self {
+        let inner_attr = attrs
+            .iter()
+            .filter(|attr| attr.style == ast::AttrStyle::Inner)
+            .cloned()
+            .collect();
+        Module {
+            ast_mod,
+            inner_attr,
+        }
+    }
+}
+
+impl<'a> HasAttrs for Module<'a> {
+    fn attrs(&self) -> &[ast::Attribute] {
+        &self.inner_attr
+    }
+    fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<ast::Attribute>)) {
+        f(&mut self.inner_attr)
+    }
+}
+
+impl<'a> AsRef<ast::Mod> for Module<'a> {
+    fn as_ref(&self) -> &ast::Mod {
+        &self.ast_mod
+    }
+}
+
 /// Maps each module to the corresponding file.
 pub(crate) struct ModResolver<'ast, 'sess> {
     parse_sess: &'sess ParseSess,
@@ -53,9 +90,9 @@ pub(crate) enum ModuleResolutionErrorKind {
 #[derive(Clone)]
 enum SubModKind<'a, 'ast> {
     /// `mod foo;`
-    External(PathBuf, DirectoryOwnership, Cow<'ast, ast::Mod>),
+    External(PathBuf, DirectoryOwnership, Module<'ast>),
     /// `mod foo;` with multiple sources.
-    MultiExternal(Vec<(PathBuf, DirectoryOwnership, Cow<'ast, ast::Mod>)>),
+    MultiExternal(Vec<(PathBuf, DirectoryOwnership, Module<'ast>)>),
     /// `mod foo {}`
     Internal(&'a ast::Item),
 }
@@ -94,8 +131,10 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
             self.visit_mod_from_ast(&krate.module)?;
         }
 
-        self.file_map
-            .insert(root_filename, Cow::Borrowed(&krate.module));
+        self.file_map.insert(
+            root_filename,
+            Module::new(Cow::Borrowed(&krate.module), &krate.attrs),
+        );
         Ok(self.file_map)
     }
 
@@ -105,7 +144,10 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
         visitor.visit_item(&item);
         for module_item in visitor.mods() {
             if let ast::ItemKind::Mod(ref sub_mod) = module_item.item.kind {
-                self.visit_sub_mod(&module_item.item, Cow::Owned(sub_mod.clone()))?;
+                self.visit_sub_mod(
+                    &module_item.item,
+                    Module::new(Cow::Owned(sub_mod.clone()), &module_item.item.attrs),
+                )?;
             }
         }
         Ok(())
@@ -120,7 +162,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
             }
 
             if let ast::ItemKind::Mod(ref sub_mod) = item.kind {
-                self.visit_sub_mod(&item, Cow::Owned(sub_mod.clone()))?;
+                self.visit_sub_mod(&item, Module::new(Cow::Owned(sub_mod.clone()), &item.attrs))?;
             }
         }
         Ok(())
@@ -134,7 +176,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
             }
 
             if let ast::ItemKind::Mod(ref sub_mod) = item.kind {
-                self.visit_sub_mod(item, Cow::Borrowed(sub_mod))?;
+                self.visit_sub_mod(item, Module::new(Cow::Borrowed(sub_mod), &item.attrs))?;
             }
         }
         Ok(())
@@ -143,12 +185,12 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
     fn visit_sub_mod(
         &mut self,
         item: &'c ast::Item,
-        sub_mod: Cow<'ast, ast::Mod>,
+        sub_mod: Module<'ast>,
     ) -> Result<(), ModuleResolutionError> {
         let old_directory = self.directory.clone();
         let sub_mod_kind = self.peek_sub_mod(item, &sub_mod)?;
         if let Some(sub_mod_kind) = sub_mod_kind {
-            self.insert_sub_mod(sub_mod_kind.clone(), sub_mod.clone())?;
+            self.insert_sub_mod(sub_mod_kind.clone())?;
             self.visit_sub_mod_inner(sub_mod, sub_mod_kind)?;
         }
         self.directory = old_directory;
@@ -159,7 +201,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
     fn peek_sub_mod(
         &self,
         item: &'c ast::Item,
-        sub_mod: &Cow<'ast, ast::Mod>,
+        sub_mod: &Module<'ast>,
     ) -> Result<Option<SubModKind<'c, 'ast>>, ModuleResolutionError> {
         if contains_skip(&item.attrs) {
             return Ok(None);
@@ -178,7 +220,6 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
     fn insert_sub_mod(
         &mut self,
         sub_mod_kind: SubModKind<'c, 'ast>,
-        _sub_mod: Cow<'ast, ast::Mod>,
     ) -> Result<(), ModuleResolutionError> {
         match sub_mod_kind {
             SubModKind::External(mod_path, _, sub_mod) => {
@@ -200,7 +241,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
 
     fn visit_sub_mod_inner(
         &mut self,
-        sub_mod: Cow<'ast, ast::Mod>,
+        sub_mod: Module<'ast>,
         sub_mod_kind: SubModKind<'c, 'ast>,
     ) -> Result<(), ModuleResolutionError> {
         match sub_mod_kind {
@@ -230,13 +271,13 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
 
     fn visit_sub_mod_after_directory_update(
         &mut self,
-        sub_mod: Cow<'ast, ast::Mod>,
+        sub_mod: Module<'ast>,
         directory: Option<Directory>,
     ) -> Result<(), ModuleResolutionError> {
         if let Some(directory) = directory {
             self.directory = directory;
         }
-        match sub_mod {
+        match sub_mod.ast_mod {
             Cow::Borrowed(sub_mod) => self.visit_mod_from_ast(sub_mod),
             Cow::Owned(sub_mod) => self.visit_mod_outside_ast(sub_mod),
         }
@@ -247,7 +288,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
         &self,
         mod_name: symbol::Ident,
         attrs: &[ast::Attribute],
-        sub_mod: &Cow<'ast, ast::Mod>,
+        sub_mod: &Module<'ast>,
     ) -> Result<Option<SubModKind<'c, 'ast>>, ModuleResolutionError> {
         let relative = match self.directory.ownership {
             DirectoryOwnership::Owned { relative } => relative,
@@ -257,11 +298,12 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
             if self.parse_sess.is_file_parsed(&path) {
                 return Ok(None);
             }
-            return match Parser::parse_file_as_module(self.parse_sess, &path, sub_mod.inner) {
+            return match Parser::parse_file_as_module(self.parse_sess, &path, sub_mod.ast_mod.inner)
+            {
                 Ok(m) => Ok(Some(SubModKind::External(
                     path,
                     DirectoryOwnership::Owned { relative: None },
-                    Cow::Owned(m),
+                    Module::new(Cow::Owned(m.0), &m.1),
                 ))),
                 Err(ParserError::ParseError) => Err(ModuleResolutionError {
                     module: mod_name.to_string(),
@@ -299,12 +341,18 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
                         return Ok(Some(SubModKind::MultiExternal(mods_outside_ast)));
                     }
                 }
-                match Parser::parse_file_as_module(self.parse_sess, &path, sub_mod.inner) {
-                    Ok(m) if outside_mods_empty => {
-                        Ok(Some(SubModKind::External(path, ownership, Cow::Owned(m))))
-                    }
+                match Parser::parse_file_as_module(self.parse_sess, &path, sub_mod.ast_mod.inner) {
+                    Ok(m) if outside_mods_empty => Ok(Some(SubModKind::External(
+                        path,
+                        ownership,
+                        Module::new(Cow::Owned(m.0), &m.1),
+                    ))),
                     Ok(m) => {
-                        mods_outside_ast.push((path.clone(), ownership, Cow::Owned(m)));
+                        mods_outside_ast.push((
+                            path.clone(),
+                            ownership,
+                            Module::new(Cow::Owned(m.0), &m.1),
+                        ));
                         if should_insert {
                             mods_outside_ast.push((path, ownership, sub_mod.clone()));
                         }
@@ -366,8 +414,8 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
     fn find_mods_outside_of_ast(
         &self,
         attrs: &[ast::Attribute],
-        sub_mod: &Cow<'ast, ast::Mod>,
-    ) -> Vec<(PathBuf, DirectoryOwnership, Cow<'ast, ast::Mod>)> {
+        sub_mod: &Module<'ast>,
+    ) -> Vec<(PathBuf, DirectoryOwnership, Module<'ast>)> {
         // Filter nested path, like `#[cfg_attr(feature = "foo", path = "bar.rs")]`.
         let mut path_visitor = visitor::PathVisitor::default();
         for attr in attrs.iter() {
@@ -394,16 +442,19 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
                 continue;
             }
 
-            let m = match Parser::parse_file_as_module(self.parse_sess, &actual_path, sub_mod.inner)
-            {
+            let m = match Parser::parse_file_as_module(
+                self.parse_sess,
+                &actual_path,
+                sub_mod.ast_mod.inner,
+            ) {
                 Ok(m) => m,
                 Err(..) => continue,
             };
 
             result.push((
                 actual_path,
                 DirectoryOwnership::Owned { relative: None },
-                Cow::Owned(m),
+                Module::new(Cow::Owned(m.0), &m.1),
             ))
         }
         result