Fixed comment dropped between & and type issue (#4482)

[rust.git] / src / visitor.rs

diff --git a/src/visitor.rs b/src/visitor.rs
index e0e1c1354c64f9dd90493b539731095114459e1b..fefeffac95c8fc416a510e215e7f6a2ff8664f65 100644 (file)
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -5,15 +5,14 @@
 use rustc_span::{symbol, BytePos, Pos, Span, DUMMY_SP};
 
 use crate::attr::*;
-use crate::comment::{rewrite_comment, CodeCharKind, CommentCodeSlices};
+use crate::comment::{contains_comment, rewrite_comment, CodeCharKind, CommentCodeSlices};
 use crate::config::Version;
 use crate::config::{BraceStyle, Config};
 use crate::coverage::transform_missing_snippet;
 use crate::items::{
     format_impl, format_trait, format_trait_alias, is_mod_decl, is_use_item,
-    rewrite_associated_impl_type, rewrite_associated_type, rewrite_extern_crate,
-    rewrite_opaque_impl_type, rewrite_opaque_type, rewrite_type_alias, FnBraceStyle, FnSig,
-    StaticParts, StructParts,
+    rewrite_associated_impl_type, rewrite_extern_crate, rewrite_opaque_impl_type,
+    rewrite_opaque_type, rewrite_type_alias, FnBraceStyle, FnSig, StaticParts, StructParts,
 };
 use crate::macros::{macro_style, rewrite_macro, rewrite_macro_def, MacroPosition};
 use crate::modules::Module;
@@ -26,7 +25,7 @@
 use crate::syntux::session::ParseSess;
 use crate::utils::{
     self, contains_skip, count_newlines, depr_skip_annotation, format_unsafety, inner_attributes,
-    last_line_width, mk_sp, ptr_vec_to_ref_vec, rewrite_ident, stmt_expr,
+    last_line_width, mk_sp, ptr_vec_to_ref_vec, rewrite_ident, starts_with_newline, stmt_expr,
 };
 use crate::{ErrorKind, FormatReport, FormattingError};
 
@@ -87,6 +86,7 @@ pub(crate) struct FmtVisitor<'a> {
     pub(crate) macro_rewrite_failure: bool,
     pub(crate) report: FormatReport,
     pub(crate) skip_context: SkipContext,
+    pub(crate) is_macro_def: bool,
 }
 
 impl<'a> Drop for FmtVisitor<'a> {
@@ -118,10 +118,22 @@ fn visit_stmt(&mut self, stmt: &Stmt<'_>) {
             self.parse_sess.span_to_debug_info(stmt.span())
         );
 
-        // https://github.com/rust-lang/rust/issues/63679.
-        let is_all_semicolons =
-            |snippet: &str| snippet.chars().all(|c| c.is_whitespace() || c == ';');
-        if is_all_semicolons(&self.snippet(stmt.span())) {
+        if stmt.is_empty() {
+            // If the statement is empty, just skip over it. Before that, make sure any comment
+            // snippet preceding the semicolon is picked up.
+            let snippet = self.snippet(mk_sp(self.last_pos, stmt.span().lo()));
+            let original_starts_with_newline = snippet
+                .find(|c| c != ' ')
+                .map_or(false, |i| starts_with_newline(&snippet[i..]));
+            let snippet = snippet.trim();
+            if !snippet.is_empty() {
+                if original_starts_with_newline {
+                    self.push_str("\n");
+                }
+                self.push_str(&self.block_indent.to_string(self.config));
+                self.push_str(snippet);
+            }
+
             self.last_pos = stmt.span().hi();
             return;
         }
@@ -249,14 +261,23 @@ fn close_block(&mut self, span: Span, unindent_comment: bool) {
             trimmed.is_empty() || trimmed.chars().all(|c| c == ';')
         };
 
-        for (kind, offset, sub_slice) in CommentCodeSlices::new(self.snippet(span)) {
+        let comment_snippet = self.snippet(span);
+
+        let align_to_right = if unindent_comment && contains_comment(&comment_snippet) {
+            let first_lines = comment_snippet.splitn(2, '/').next().unwrap_or("");
+            last_line_width(first_lines) > last_line_width(&comment_snippet)
+        } else {
+            false
+        };
+
+        for (kind, offset, sub_slice) in CommentCodeSlices::new(comment_snippet) {
             let sub_slice = transform_missing_snippet(config, sub_slice);
 
             debug!("close_block: {:?} {:?} {:?}", kind, offset, sub_slice);
 
             match kind {
                 CodeCharKind::Comment => {
-                    if !unindented && unindent_comment {
+                    if !unindented && unindent_comment && !align_to_right {
                         unindented = true;
                         self.block_indent = self.block_indent.block_unindent(config);
                     }
@@ -349,7 +370,7 @@ fn unindent_comment_on_closing_brace(&self, b: &ast::Block) -> bool {
 
     // Note that this only gets called for function definitions. Required methods
     // on traits do not get handled here.
-    fn visit_fn(
+    pub(crate) fn visit_fn(
         &mut self,
         fk: visit::FnKind<'_>,
         generics: &ast::Generics,
@@ -544,12 +565,14 @@ pub(crate) fn visit_item(&mut self, item: &ast::Item) {
                 ast::ItemKind::TyAlias(_, ref generics, ref generic_bounds, ref ty) => match ty {
                     Some(ty) => {
                         let rewrite = rewrite_type_alias(
-                            &self.get_context(),
-                            self.block_indent,
                             item.ident,
-                            &*ty,
+                            Some(&*ty),
                             generics,
+                            Some(generic_bounds),
+                            &self.get_context(),
+                            self.block_indent,
                             &item.vis,
+                            item.span,
                         );
                         self.push_rewrite(item.span, rewrite);
                     }
@@ -561,6 +584,7 @@ pub(crate) fn visit_item(&mut self, item: &ast::Item) {
                             generic_bounds,
                             generics,
                             &item.vis,
+                            item.span,
                         );
                         self.push_rewrite(item.span, rewrite);
                     }
@@ -619,13 +643,15 @@ pub(crate) fn visit_trait_item(&mut self, ti: &ast::AssocItem) {
                 );
             }
             ast::AssocItemKind::TyAlias(_, ref generics, ref generic_bounds, ref type_default) => {
-                let rewrite = rewrite_associated_type(
+                let rewrite = rewrite_type_alias(
                     ti.ident,
                     type_default.as_ref(),
                     generics,
                     Some(generic_bounds),
                     &self.get_context(),
                     self.block_indent,
+                    &ti.vis,
+                    ti.span,
                 );
                 self.push_rewrite(ti.span, rewrite);
             }
@@ -666,11 +692,13 @@ pub(crate) fn visit_impl_item(&mut self, ii: &ast::AssocItem) {
                 let rewrite_associated = || {
                     rewrite_associated_impl_type(
                         ii.ident,
+                        &ii.vis,
                         defaultness,
                         ty.as_ref(),
                         &generics,
                         &self.get_context(),
                         self.block_indent,
+                        ii.span,
                     )
                 };
                 let rewrite = match ty {
@@ -797,6 +825,7 @@ pub(crate) fn from_parse_sess(
             snippet_provider,
             line_number: 0,
             skipped_range: Rc::new(RefCell::new(vec![])),
+            is_macro_def: false,
             macro_rewrite_failure: false,
             report,
             skip_context: Default::default(),
@@ -826,7 +855,7 @@ pub(crate) fn visit_attrs(&mut self, attrs: &[ast::Attribute], style: ast::AttrS
                 );
             } else {
                 match &attr.kind {
-                    ast::AttrKind::Normal(ref attribute_item)
+                    ast::AttrKind::Normal(ref attribute_item, _)
                         if self.is_unknown_rustfmt_attr(&attribute_item.path.segments) =>
                     {
                         let file_name = self.parse_sess.span_to_filename(attr.span);
@@ -989,6 +1018,7 @@ pub(crate) fn get_context(&self) -> RewriteContext<'_> {
             force_one_line_chain: Cell::new(false),
             snippet_provider: self.snippet_provider,
             macro_rewrite_failure: Cell::new(false),
+            is_macro_def: self.is_macro_def,
             report: self.report.clone(),
             skip_context: self.skip_context.clone(),
             skipped_range: self.skipped_range.clone(),