]> git.lizzy.rs Git - rust.git/blobdiff - src/visitor.rs
Fixed comment dropped between & and type issue (#4482)
[rust.git] / src / visitor.rs
index c6ae3b3be1e866cd332b2f58d6e6a8d6ef36c672..fefeffac95c8fc416a510e215e7f6a2ff8664f65 100644 (file)
@@ -1,56 +1,52 @@
 use std::cell::{Cell, RefCell};
 use std::rc::Rc;
 
-use rustc_session::parse::ParseSess;
-use rustc_span::{
-    source_map::{self, SourceMap},
-    BytePos, Pos, Span,
-};
-use syntax::token::DelimToken;
-use syntax::{ast, visit};
+use rustc_ast::{ast, attr::HasAttrs, token::DelimToken, visit};
+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;
 use crate::rewrite::{Rewrite, RewriteContext};
 use crate::shape::{Indent, Shape};
 use crate::skip::{is_skip_attr, SkipContext};
 use crate::source_map::{LineRangeUtils, SpanUtils};
 use crate::spanned::Spanned;
 use crate::stmt::Stmt;
+use crate::syntux::session::ParseSess;
 use crate::utils::{
-    self, contains_skip, count_newlines, depr_skip_annotation, inner_attributes, last_line_width,
-    mk_sp, ptr_vec_to_ref_vec, rewrite_ident, stmt_expr,
+    self, contains_skip, count_newlines, depr_skip_annotation, format_unsafety, inner_attributes,
+    last_line_width, mk_sp, ptr_vec_to_ref_vec, rewrite_ident, starts_with_newline, stmt_expr,
 };
 use crate::{ErrorKind, FormatReport, FormattingError};
 
 /// Creates a string slice corresponding to the specified span.
-pub(crate) struct SnippetProvider<'a> {
+pub(crate) struct SnippetProvider {
     /// A pointer to the content of the file we are formatting.
-    big_snippet: &'a str,
+    big_snippet: Rc<String>,
     /// A position of the start of `big_snippet`, used as an offset.
     start_pos: usize,
     /// A end position of the file that this snippet lives.
     end_pos: usize,
 }
 
-impl<'a> SnippetProvider<'a> {
+impl SnippetProvider {
     pub(crate) fn span_to_snippet(&self, span: Span) -> Option<&str> {
         let start_index = span.lo().to_usize().checked_sub(self.start_pos)?;
         let end_index = span.hi().to_usize().checked_sub(self.start_pos)?;
         Some(&self.big_snippet[start_index..end_index])
     }
 
-    pub(crate) fn new(start_pos: BytePos, end_pos: BytePos, big_snippet: &'a str) -> Self {
+    pub(crate) fn new(start_pos: BytePos, end_pos: BytePos, big_snippet: Rc<String>) -> Self {
         let start_pos = start_pos.to_usize();
         let end_pos = end_pos.to_usize();
         SnippetProvider {
@@ -60,6 +56,14 @@ pub(crate) fn new(start_pos: BytePos, end_pos: BytePos, big_snippet: &'a str) ->
         }
     }
 
+    pub(crate) fn entire_snippet(&self) -> &str {
+        self.big_snippet.as_str()
+    }
+
+    pub(crate) fn start_pos(&self) -> BytePos {
+        BytePos::from_usize(self.start_pos)
+    }
+
     pub(crate) fn end_pos(&self) -> BytePos {
         BytePos::from_usize(self.end_pos)
     }
@@ -67,15 +71,14 @@ pub(crate) fn end_pos(&self) -> BytePos {
 
 pub(crate) struct FmtVisitor<'a> {
     parent_context: Option<&'a RewriteContext<'a>>,
-    pub(crate) parse_session: &'a ParseSess,
-    pub(crate) source_map: &'a SourceMap,
+    pub(crate) parse_sess: &'a ParseSess,
     pub(crate) buffer: String,
     pub(crate) last_pos: BytePos,
     // FIXME: use an RAII util or closure for indenting
     pub(crate) block_indent: Indent,
     pub(crate) config: &'a Config,
     pub(crate) is_if_else_block: bool,
-    pub(crate) snippet_provider: &'a SnippetProvider<'a>,
+    pub(crate) snippet_provider: &'a SnippetProvider,
     pub(crate) line_number: usize,
     /// List of 1-based line ranges which were annotated with skip
     /// Both bounds are inclusifs.
@@ -83,6 +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> {
@@ -110,16 +114,26 @@ fn next_span(&self, hi: BytePos) -> Span {
 
     fn visit_stmt(&mut self, stmt: &Stmt<'_>) {
         debug!(
-            "visit_stmt: {:?} {:?} `{}`",
-            self.source_map.lookup_char_pos(stmt.span().lo()),
-            self.source_map.lookup_char_pos(stmt.span().hi()),
-            self.snippet(stmt.span()),
+            "visit_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;
         }
@@ -144,19 +158,19 @@ fn visit_stmt(&mut self, stmt: &Stmt<'_>) {
                     self.push_rewrite(stmt.span(), rewrite)
                 }
             }
-            ast::StmtKind::Mac(ref mac) => {
-                let (ref mac, _macro_style, ref attrs) = **mac;
-                if self.visit_attrs(attrs, ast::AttrStyle::Outer) {
+            ast::StmtKind::MacCall(ref mac_stmt) => {
+                if self.visit_attrs(&mac_stmt.attrs, ast::AttrStyle::Outer) {
                     self.push_skipped_with_span(
-                        attrs,
+                        &mac_stmt.attrs,
                         stmt.span(),
                         get_span_without_attrs(stmt.as_ast_node()),
                     );
                 } else {
-                    self.visit_mac(mac, None, MacroPosition::Statement);
+                    self.visit_mac(&mac_stmt.mac, None, MacroPosition::Statement);
                 }
                 self.format_missing(stmt.span().hi());
             }
+            ast::StmtKind::Empty => (),
         }
     }
 
@@ -195,9 +209,8 @@ pub(crate) fn visit_block(
         has_braces: bool,
     ) {
         debug!(
-            "visit_block: {:?} {:?}",
-            self.source_map.lookup_char_pos(b.span.lo()),
-            self.source_map.lookup_char_pos(b.span.hi())
+            "visit_block: {}",
+            self.parse_sess.span_to_debug_info(b.span),
         );
 
         // Check if this block has braces.
@@ -248,14 +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);
                     }
@@ -348,7 +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,
@@ -497,7 +519,7 @@ pub(crate) fn visit_item(&mut self, item: &ast::Item) {
                     self.format_missing_with_indent(source!(self, item.span).lo());
                     self.format_mod(module, &item.vis, item.span, item.ident, attrs, is_inline);
                 }
-                ast::ItemKind::Mac(ref mac) => {
+                ast::ItemKind::MacCall(ref mac) => {
                     self.visit_mac(mac, Some(item.ident), MacroPosition::Item);
                 }
                 ast::ItemKind::ForeignMod(ref foreign_mod) => {
@@ -507,7 +529,7 @@ pub(crate) fn visit_item(&mut self, item: &ast::Item) {
                 ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => {
                     self.visit_static(&StaticParts::from_item(item));
                 }
-                ast::ItemKind::Fn(ref fn_signature, ref generics, ref body) => {
+                ast::ItemKind::Fn(defaultness, ref fn_signature, ref generics, Some(ref body)) => {
                     let inner_attrs = inner_attributes(&item.attrs);
                     let fn_ctxt = match fn_signature.header.ext {
                         ast::Extern::None => visit::FnCtxt::Free,
@@ -519,28 +541,42 @@ pub(crate) fn visit_item(&mut self, item: &ast::Item) {
                             item.ident,
                             &fn_signature,
                             &item.vis,
-                            body.as_deref(),
+                            Some(body),
                         ),
                         generics,
                         &fn_signature.decl,
                         item.span,
-                        ast::Defaultness::Final,
+                        defaultness,
                         Some(&inner_attrs),
                     )
                 }
-                ast::ItemKind::TyAlias(ref ty, ref generics) => match ty.kind.opaque_top_hack() {
-                    None => {
+                ast::ItemKind::Fn(_, ref fn_signature, ref generics, None) => {
+                    let indent = self.block_indent;
+                    let rewrite = self.rewrite_required_fn(
+                        indent,
+                        item.ident,
+                        &fn_signature,
+                        generics,
+                        item.span,
+                    );
+
+                    self.push_rewrite(item.span, rewrite);
+                }
+                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);
                     }
-                    Some(generic_bounds) => {
+                    None => {
                         let rewrite = rewrite_opaque_type(
                             &self.get_context(),
                             self.block_indent,
@@ -548,6 +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);
                     }
@@ -583,37 +620,42 @@ pub(crate) fn visit_trait_item(&mut self, ti: &ast::AssocItem) {
 
         match ti.kind {
             ast::AssocItemKind::Const(..) => self.visit_static(&StaticParts::from_trait_item(ti)),
-            ast::AssocItemKind::Fn(ref sig, None) => {
+            ast::AssocItemKind::Fn(_, ref sig, ref generics, None) => {
                 let indent = self.block_indent;
-                let rewrite =
-                    self.rewrite_required_fn(indent, ti.ident, sig, &ti.generics, ti.span);
+                let rewrite = self.rewrite_required_fn(indent, ti.ident, sig, generics, ti.span);
                 self.push_rewrite(ti.span, rewrite);
             }
-            ast::AssocItemKind::Fn(ref sig, Some(ref body)) => {
+            ast::AssocItemKind::Fn(defaultness, ref sig, ref generics, Some(ref body)) => {
                 let inner_attrs = inner_attributes(&ti.attrs);
-                let vis = rustc_span::source_map::dummy_spanned(ast::VisibilityKind::Inherited);
+                let vis = ast::Visibility {
+                    kind: ast::VisibilityKind::Inherited,
+                    span: DUMMY_SP,
+                    tokens: None,
+                };
                 let fn_ctxt = visit::FnCtxt::Assoc(visit::AssocCtxt::Trait);
                 self.visit_fn(
                     visit::FnKind::Fn(fn_ctxt, ti.ident, sig, &vis, Some(body)),
-                    &ti.generics,
+                    generics,
                     &sig.decl,
                     ti.span,
-                    ast::Defaultness::Final,
+                    defaultness,
                     Some(&inner_attrs),
                 );
             }
-            ast::AssocItemKind::TyAlias(ref generic_bounds, ref type_default) => {
-                let rewrite = rewrite_associated_type(
+            ast::AssocItemKind::TyAlias(_, ref generics, ref generic_bounds, ref type_default) => {
+                let rewrite = rewrite_type_alias(
                     ti.ident,
                     type_default.as_ref(),
-                    &ti.generics,
+                    generics,
                     Some(generic_bounds),
                     &self.get_context(),
                     self.block_indent,
+                    &ti.vis,
+                    ti.span,
                 );
                 self.push_rewrite(ti.span, rewrite);
             }
-            ast::AssocItemKind::Macro(ref mac) => {
+            ast::AssocItemKind::MacCall(ref mac) => {
                 self.visit_mac(mac, Some(ti.ident), MacroPosition::Item);
             }
         }
@@ -628,58 +670,59 @@ pub(crate) fn visit_impl_item(&mut self, ii: &ast::AssocItem) {
         }
 
         match ii.kind {
-            ast::AssocItemKind::Fn(ref sig, Some(ref body)) => {
+            ast::AssocItemKind::Fn(defaultness, ref sig, ref generics, Some(ref body)) => {
                 let inner_attrs = inner_attributes(&ii.attrs);
                 let fn_ctxt = visit::FnCtxt::Assoc(visit::AssocCtxt::Impl);
                 self.visit_fn(
                     visit::FnKind::Fn(fn_ctxt, ii.ident, sig, &ii.vis, Some(body)),
-                    &ii.generics,
+                    generics,
                     &sig.decl,
                     ii.span,
-                    ii.defaultness,
+                    defaultness,
                     Some(&inner_attrs),
                 );
             }
-            ast::AssocItemKind::Fn(ref sig, None) => {
+            ast::AssocItemKind::Fn(_, ref sig, ref generics, None) => {
                 let indent = self.block_indent;
-                let rewrite =
-                    self.rewrite_required_fn(indent, ii.ident, sig, &ii.generics, ii.span);
+                let rewrite = self.rewrite_required_fn(indent, ii.ident, sig, generics, ii.span);
                 self.push_rewrite(ii.span, rewrite);
             }
             ast::AssocItemKind::Const(..) => self.visit_static(&StaticParts::from_impl_item(ii)),
-            ast::AssocItemKind::TyAlias(_, ref ty) => {
+            ast::AssocItemKind::TyAlias(defaultness, ref generics, _, ref ty) => {
                 let rewrite_associated = || {
                     rewrite_associated_impl_type(
                         ii.ident,
-                        ii.defaultness,
+                        &ii.vis,
+                        defaultness,
                         ty.as_ref(),
-                        &ii.generics,
+                        &generics,
                         &self.get_context(),
                         self.block_indent,
+                        ii.span,
                     )
                 };
                 let rewrite = match ty {
                     None => rewrite_associated(),
-                    Some(ty) => match ty.kind.opaque_top_hack() {
-                        Some(generic_bounds) => rewrite_opaque_impl_type(
+                    Some(ty) => match ty.kind {
+                        ast::TyKind::ImplTrait(_, ref bounds) => rewrite_opaque_impl_type(
                             &self.get_context(),
                             ii.ident,
-                            &ii.generics,
-                            generic_bounds,
+                            generics,
+                            bounds,
                             self.block_indent,
                         ),
-                        None => rewrite_associated(),
+                        _ => rewrite_associated(),
                     },
                 };
                 self.push_rewrite(ii.span, rewrite);
             }
-            ast::AssocItemKind::Macro(ref mac) => {
+            ast::AssocItemKind::MacCall(ref mac) => {
                 self.visit_mac(mac, Some(ii.ident), MacroPosition::Item);
             }
         }
     }
 
-    fn visit_mac(&mut self, mac: &ast::Mac, ident: Option<ast::Ident>, pos: MacroPosition) {
+    fn visit_mac(&mut self, mac: &ast::MacCall, ident: Option<symbol::Ident>, pos: MacroPosition) {
         skip_out_of_file_lines_range_visitor!(self, mac.span());
 
         // 1 = ;
@@ -740,10 +783,10 @@ pub(crate) fn push_skipped_with_span(
         // do not take into account the lines with attributes as part of the skipped range
         let attrs_end = attrs
             .iter()
-            .map(|attr| self.source_map.lookup_char_pos(attr.span.hi()).line)
+            .map(|attr| self.parse_sess.line_of_byte_pos(attr.span.hi()))
             .max()
             .unwrap_or(1);
-        let first_line = self.source_map.lookup_char_pos(main_span.lo()).line;
+        let first_line = self.parse_sess.line_of_byte_pos(main_span.lo());
         // Statement can start after some newlines and/or spaces
         // or it can be on the same line as the last attribute.
         // So here we need to take a minimum between the two.
@@ -754,8 +797,8 @@ pub(crate) fn push_skipped_with_span(
     }
 
     pub(crate) fn from_context(ctx: &'a RewriteContext<'_>) -> FmtVisitor<'a> {
-        let mut visitor = FmtVisitor::from_source_map(
-            ctx.parse_session,
+        let mut visitor = FmtVisitor::from_parse_sess(
+            ctx.parse_sess,
             ctx.config,
             ctx.snippet_provider,
             ctx.report.clone(),
@@ -765,16 +808,15 @@ pub(crate) fn from_context(ctx: &'a RewriteContext<'_>) -> FmtVisitor<'a> {
         visitor
     }
 
-    pub(crate) fn from_source_map(
+    pub(crate) fn from_parse_sess(
         parse_session: &'a ParseSess,
         config: &'a Config,
-        snippet_provider: &'a SnippetProvider<'_>,
+        snippet_provider: &'a SnippetProvider,
         report: FormatReport,
     ) -> FmtVisitor<'a> {
         FmtVisitor {
             parent_context: None,
-            parse_session,
-            source_map: parse_session.source_map(),
+            parse_sess: parse_session,
             buffer: String::with_capacity(snippet_provider.big_snippet.len() * 2),
             last_pos: BytePos(0),
             block_indent: Indent::empty(),
@@ -783,6 +825,7 @@ pub(crate) fn from_source_map(
             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(),
@@ -800,27 +843,27 @@ pub(crate) fn snippet(&'b self, span: Span) -> &'a str {
     // Returns true if we should skip the following item.
     pub(crate) fn visit_attrs(&mut self, attrs: &[ast::Attribute], style: ast::AttrStyle) -> bool {
         for attr in attrs {
-            if attr.check_name(depr_skip_annotation()) {
-                let file_name = self.source_map.span_to_filename(attr.span).into();
+            if attr.has_name(depr_skip_annotation()) {
+                let file_name = self.parse_sess.span_to_filename(attr.span);
                 self.report.append(
                     file_name,
                     vec![FormattingError::from_span(
                         attr.span,
-                        &self.source_map,
+                        self.parse_sess,
                         ErrorKind::DeprecatedAttr,
                     )],
                 );
             } 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.source_map.span_to_filename(attr.span).into();
+                        let file_name = self.parse_sess.span_to_filename(attr.span);
                         self.report.append(
                             file_name,
                             vec![FormattingError::from_span(
                                 attr.span,
-                                self.source_map,
+                                self.parse_sess,
                                 ErrorKind::BadAttr,
                             )],
                         );
@@ -886,12 +929,13 @@ fn format_mod(
         m: &ast::Mod,
         vis: &ast::Visibility,
         s: Span,
-        ident: ast::Ident,
+        ident: symbol::Ident,
         attrs: &[ast::Attribute],
         is_internal: bool,
     ) {
         let vis_str = utils::format_visibility(&self.get_context(), vis);
         self.push_str(&*vis_str);
+        self.push_str(format_unsafety(m.unsafety));
         self.push_str("mod ");
         // Calling `to_owned()` to work around borrow checker.
         let ident_str = rewrite_ident(&self.get_context(), ident).to_owned();
@@ -928,14 +972,14 @@ fn format_mod(
         }
     }
 
-    pub(crate) fn format_separate_mod(
-        &mut self,
-        m: &ast::Mod,
-        source_file: &source_map::SourceFile,
-    ) {
+    pub(crate) fn format_separate_mod(&mut self, m: &Module<'_>, end_pos: BytePos) {
         self.block_indent = Indent::empty();
-        self.walk_mod_items(m);
-        self.format_missing_with_indent(source_file.end_pos);
+        if self.visit_attrs(m.attrs(), ast::AttrStyle::Inner) {
+            self.push_skipped_with_span(m.attrs(), m.as_ref().inner, m.as_ref().inner);
+        } else {
+            self.walk_mod_items(m.as_ref());
+            self.format_missing_with_indent(end_pos);
+        }
     }
 
     pub(crate) fn skip_empty_lines(&mut self, end_pos: BytePos) {
@@ -966,8 +1010,7 @@ pub(crate) fn with_context<F>(&mut self, f: F) -> Option<String>
 
     pub(crate) fn get_context(&self) -> RewriteContext<'_> {
         RewriteContext {
-            parse_session: self.parse_session,
-            source_map: self.source_map,
+            parse_sess: self.parse_sess,
             config: self.config,
             inside_macro: Rc::new(Cell::new(false)),
             use_block: Cell::new(false),
@@ -975,6 +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(),