src/visitor.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use syntax::attr::HasAttrs;
  12 use syntax::parse::ParseSess;
  13 use syntax::source_map::{self, BytePos, Pos, SourceMap, Span};
  14 use syntax::{ast, visit};
  15
  16 use attr::*;
  17 use comment::{CodeCharKind, CommentCodeSlices, FindUncommented};
  18 use config::{BraceStyle, Config};
  19 use items::{
  20     format_impl, format_trait, format_trait_alias, is_mod_decl, is_use_item,
  21     rewrite_associated_impl_type, rewrite_associated_type, rewrite_existential_impl_type,
  22     rewrite_existential_type, rewrite_extern_crate, rewrite_type_alias, FnSig, StaticParts,
  23     StructParts,
  24 };
  25 use macros::{rewrite_macro, rewrite_macro_def, MacroPosition};
  26 use rewrite::{Rewrite, RewriteContext};
  27 use shape::{Indent, Shape};
  28 use source_map::{LineRangeUtils, SpanUtils};
  29 use spanned::Spanned;
  30 use utils::{
  31     self, contains_skip, count_newlines, inner_attributes, mk_sp, ptr_vec_to_ref_vec,
  32     rewrite_ident, DEPR_SKIP_ANNOTATION,
  33 };
  34 use {ErrorKind, FormatReport, FormattingError};
  35
  36 use std::cell::RefCell;
  37
  38 /// Creates a string slice corresponding to the specified span.
  39 pub struct SnippetProvider<'a> {
  40     /// A pointer to the content of the file we are formatting.
  41     big_snippet: &'a str,
  42     /// A position of the start of `big_snippet`, used as an offset.
  43     start_pos: usize,
  44 }
  45
  46 impl<'a> SnippetProvider<'a> {
  47     pub fn span_to_snippet(&self, span: Span) -> Option<&str> {
  48         let start_index = span.lo().to_usize().checked_sub(self.start_pos)?;
  49         let end_index = span.hi().to_usize().checked_sub(self.start_pos)?;
  50         Some(&self.big_snippet[start_index..end_index])
  51     }
  52
  53     pub fn new(start_pos: BytePos, big_snippet: &'a str) -> Self {
  54         let start_pos = start_pos.to_usize();
  55         SnippetProvider {
  56             big_snippet,
  57             start_pos,
  58         }
  59     }
  60 }
  61
  62 pub struct FmtVisitor<'a> {
  63     pub parse_session: &'a ParseSess,
  64     pub source_map: &'a SourceMap,
  65     pub buffer: String,
  66     pub last_pos: BytePos,
  67     // FIXME: use an RAII util or closure for indenting
  68     pub block_indent: Indent,
  69     pub config: &'a Config,
  70     pub is_if_else_block: bool,
  71     pub snippet_provider: &'a SnippetProvider<'a>,
  72     pub line_number: usize,
  73     pub skipped_range: Vec<(usize, usize)>,
  74     pub macro_rewrite_failure: bool,
  75     pub(crate) report: FormatReport,
  76 }
  77
  78 impl<'b, 'a: 'b> FmtVisitor<'a> {
  79     pub fn shape(&self) -> Shape {
  80         Shape::indented(self.block_indent, self.config)
  81     }
  82
  83     fn visit_stmt(&mut self, stmt: &ast::Stmt) {
  84         debug!(
  85             "visit_stmt: {:?} {:?}",
  86             self.source_map.lookup_char_pos(stmt.span.lo()),
  87             self.source_map.lookup_char_pos(stmt.span.hi())
  88         );
  89
  90         match stmt.node {
  91             ast::StmtKind::Item(ref item) => {
  92                 self.visit_item(item);
  93                 // Handle potential `;` after the item.
  94                 self.format_missing(stmt.span.hi());
  95             }
  96             ast::StmtKind::Local(..) | ast::StmtKind::Expr(..) | ast::StmtKind::Semi(..) => {
  97                 if contains_skip(get_attrs_from_stmt(stmt)) {
  98                     self.push_skipped_with_span(stmt.span());
  99                 } else {
 100                     let rewrite = stmt.rewrite(&self.get_context(), self.shape());
 101                     self.push_rewrite(stmt.span(), rewrite)
 102                 }
 103             }
 104             ast::StmtKind::Mac(ref mac) => {
 105                 let (ref mac, _macro_style, ref attrs) = **mac;
 106                 if self.visit_attrs(attrs, ast::AttrStyle::Outer) {
 107                     self.push_skipped_with_span(stmt.span());
 108                 } else {
 109                     self.visit_mac(mac, None, MacroPosition::Statement);
 110                 }
 111                 self.format_missing(stmt.span.hi());
 112             }
 113         }
 114     }
 115
 116     pub fn visit_block(
 117         &mut self,
 118         b: &ast::Block,
 119         inner_attrs: Option<&[ast::Attribute]>,
 120         has_braces: bool,
 121     ) {
 122         debug!(
 123             "visit_block: {:?} {:?}",
 124             self.source_map.lookup_char_pos(b.span.lo()),
 125             self.source_map.lookup_char_pos(b.span.hi())
 126         );
 127
 128         // Check if this block has braces.
 129         let brace_compensation = BytePos(if has_braces { 1 } else { 0 });
 130
 131         self.last_pos = self.last_pos + brace_compensation;
 132         self.block_indent = self.block_indent.block_indent(self.config);
 133         self.push_str("{");
 134
 135         if let Some(first_stmt) = b.stmts.first() {
 136             let attr_lo = inner_attrs
 137                 .and_then(|attrs| inner_attributes(attrs).first().map(|attr| attr.span.lo()))
 138                 .or_else(|| {
 139                     // Attributes for an item in a statement position
 140                     // do not belong to the statement. (rust-lang/rust#34459)
 141                     if let ast::StmtKind::Item(ref item) = first_stmt.node {
 142                         item.attrs.first()
 143                     } else {
 144                         first_stmt.attrs().first()
 145                     }.and_then(|attr| {
 146                         // Some stmts can have embedded attributes.
 147                         // e.g. `match { #![attr] ... }`
 148                         let attr_lo = attr.span.lo();
 149                         if attr_lo < first_stmt.span.lo() {
 150                             Some(attr_lo)
 151                         } else {
 152                             None
 153                         }
 154                     })
 155                 });
 156
 157             let snippet = self.snippet(mk_sp(
 158                 self.last_pos,
 159                 attr_lo.unwrap_or_else(|| first_stmt.span.lo()),
 160             ));
 161             let len = CommentCodeSlices::new(snippet)
 162                 .nth(0)
 163                 .and_then(|(kind, _, s)| {
 164                     if kind == CodeCharKind::Normal {
 165                         s.rfind('\n')
 166                     } else {
 167                         None
 168                     }
 169                 });
 170             if let Some(len) = len {
 171                 self.last_pos = self.last_pos + BytePos::from_usize(len);
 172             }
 173         }
 174
 175         // Format inner attributes if available.
 176         let skip_rewrite = if let Some(attrs) = inner_attrs {
 177             self.visit_attrs(attrs, ast::AttrStyle::Inner)
 178         } else {
 179             false
 180         };
 181
 182         if skip_rewrite {
 183             self.push_rewrite(b.span, None);
 184             self.close_block(false);
 185             self.last_pos = source!(self, b.span).hi();
 186             return;
 187         }
 188
 189         self.walk_block_stmts(b);
 190
 191         if !b.stmts.is_empty() {
 192             if let Some(expr) = utils::stmt_expr(&b.stmts[b.stmts.len() - 1]) {
 193                 if utils::semicolon_for_expr(&self.get_context(), expr) {
 194                     self.push_str(";");
 195                 }
 196             }
 197         }
 198
 199         let mut remove_len = BytePos(0);
 200         if let Some(stmt) = b.stmts.last() {
 201             let snippet = self.snippet(mk_sp(
 202                 stmt.span.hi(),
 203                 source!(self, b.span).hi() - brace_compensation,
 204             ));
 205             let len = CommentCodeSlices::new(snippet)
 206                 .last()
 207                 .and_then(|(kind, _, s)| {
 208                     if kind == CodeCharKind::Normal && s.trim().is_empty() {
 209                         Some(s.len())
 210                     } else {
 211                         None
 212                     }
 213                 });
 214             if let Some(len) = len {
 215                 remove_len = BytePos::from_usize(len);
 216             }
 217         }
 218
 219         let unindent_comment = (self.is_if_else_block && !b.stmts.is_empty()) && {
 220             let end_pos = source!(self, b.span).hi() - brace_compensation - remove_len;
 221             let snippet = self.snippet(mk_sp(self.last_pos, end_pos));
 222             snippet.contains("//") || snippet.contains("/*")
 223         };
 224         // FIXME: we should compress any newlines here to just one
 225         if unindent_comment {
 226             self.block_indent = self.block_indent.block_unindent(self.config);
 227         }
 228         self.format_missing_with_indent(
 229             source!(self, b.span).hi() - brace_compensation - remove_len,
 230         );
 231         if unindent_comment {
 232             self.block_indent = self.block_indent.block_indent(self.config);
 233         }
 234         self.close_block(unindent_comment);
 235         self.last_pos = source!(self, b.span).hi();
 236     }
 237
 238     // FIXME: this is a terrible hack to indent the comments between the last
 239     // item in the block and the closing brace to the block's level.
 240     // The closing brace itself, however, should be indented at a shallower
 241     // level.
 242     fn close_block(&mut self, unindent_comment: bool) {
 243         let total_len = self.buffer.len();
 244         let chars_too_many = if unindent_comment {
 245             0
 246         } else if self.config.hard_tabs() {
 247             1
 248         } else {
 249             self.config.tab_spaces()
 250         };
 251         self.buffer.truncate(total_len - chars_too_many);
 252         self.push_str("}");
 253         self.block_indent = self.block_indent.block_unindent(self.config);
 254     }
 255
 256     // Note that this only gets called for function definitions. Required methods
 257     // on traits do not get handled here.
 258     fn visit_fn(
 259         &mut self,
 260         fk: visit::FnKind,
 261         generics: &ast::Generics,
 262         fd: &ast::FnDecl,
 263         s: Span,
 264         defaultness: ast::Defaultness,
 265         inner_attrs: Option<&[ast::Attribute]>,
 266     ) {
 267         let indent = self.block_indent;
 268         let block;
 269         let rewrite = match fk {
 270             visit::FnKind::ItemFn(ident, _, _, b) | visit::FnKind::Method(ident, _, _, b) => {
 271                 block = b;
 272                 self.rewrite_fn(
 273                     indent,
 274                     ident,
 275                     &FnSig::from_fn_kind(&fk, generics, fd, defaultness),
 276                     mk_sp(s.lo(), b.span.lo()),
 277                     b,
 278                     inner_attrs,
 279                 )
 280             }
 281             visit::FnKind::Closure(_) => unreachable!(),
 282         };
 283
 284         if let Some(fn_str) = rewrite {
 285             self.format_missing_with_indent(source!(self, s).lo());
 286             self.push_str(&fn_str);
 287             if let Some(c) = fn_str.chars().last() {
 288                 if c == '}' {
 289                     self.last_pos = source!(self, block.span).hi();
 290                     return;
 291                 }
 292             }
 293         } else {
 294             self.format_missing(source!(self, block.span).lo());
 295         }
 296
 297         self.last_pos = source!(self, block.span).lo();
 298         self.visit_block(block, inner_attrs, true)
 299     }
 300
 301     pub fn visit_item(&mut self, item: &ast::Item) {
 302         skip_out_of_file_lines_range_visitor!(self, item.span);
 303
 304         // This is where we bail out if there is a skip attribute. This is only
 305         // complex in the module case. It is complex because the module could be
 306         // in a separate file and there might be attributes in both files, but
 307         // the AST lumps them all together.
 308         let filtered_attrs;
 309         let mut attrs = &item.attrs;
 310         match item.node {
 311             // For use items, skip rewriting attributes. Just check for a skip attribute.
 312             ast::ItemKind::Use(..) => {
 313                 if contains_skip(attrs) {
 314                     self.push_skipped_with_span(item.span());
 315                     return;
 316                 }
 317             }
 318             // Module is inline, in this case we treat it like any other item.
 319             _ if !is_mod_decl(item) => {
 320                 if self.visit_attrs(&item.attrs, ast::AttrStyle::Outer) {
 321                     self.push_skipped_with_span(item.span());
 322                     return;
 323                 }
 324             }
 325             // Module is not inline, but should be skipped.
 326             ast::ItemKind::Mod(..) if contains_skip(&item.attrs) => {
 327                 return;
 328             }
 329             // Module is not inline and should not be skipped. We want
 330             // to process only the attributes in the current file.
 331             ast::ItemKind::Mod(..) => {
 332                 filtered_attrs = filter_inline_attrs(&item.attrs, item.span());
 333                 // Assert because if we should skip it should be caught by
 334                 // the above case.
 335                 assert!(!self.visit_attrs(&filtered_attrs, ast::AttrStyle::Outer));
 336                 attrs = &filtered_attrs;
 337             }
 338             _ => {
 339                 if self.visit_attrs(&item.attrs, ast::AttrStyle::Outer) {
 340                     self.push_skipped_with_span(item.span());
 341                     return;
 342                 }
 343             }
 344         }
 345
 346         match item.node {
 347             ast::ItemKind::Use(ref tree) => self.format_import(item, tree),
 348             ast::ItemKind::Impl(..) => {
 349                 let snippet = self.snippet(item.span);
 350                 let where_span_end = snippet
 351                     .find_uncommented("{")
 352                     .map(|x| BytePos(x as u32) + source!(self, item.span).lo());
 353                 let rw = format_impl(&self.get_context(), item, self.block_indent, where_span_end);
 354                 self.push_rewrite(item.span, rw);
 355             }
 356             ast::ItemKind::Trait(..) => {
 357                 let rw = format_trait(&self.get_context(), item, self.block_indent);
 358                 self.push_rewrite(item.span, rw);
 359             }
 360             ast::ItemKind::TraitAlias(ref generics, ref generic_bounds) => {
 361                 let shape = Shape::indented(self.block_indent, self.config);
 362                 let rw = format_trait_alias(
 363                     &self.get_context(),
 364                     item.ident,
 365                     generics,
 366                     generic_bounds,
 367                     shape,
 368                 );
 369                 self.push_rewrite(item.span, rw);
 370             }
 371             ast::ItemKind::ExternCrate(_) => {
 372                 let rw = rewrite_extern_crate(&self.get_context(), item);
 373                 self.push_rewrite(item.span, rw);
 374             }
 375             ast::ItemKind::Struct(..) | ast::ItemKind::Union(..) => {
 376                 self.visit_struct(&StructParts::from_item(item));
 377             }
 378             ast::ItemKind::Enum(ref def, ref generics) => {
 379                 self.format_missing_with_indent(source!(self, item.span).lo());
 380                 self.visit_enum(item.ident, &item.vis, def, generics, item.span);
 381                 self.last_pos = source!(self, item.span).hi();
 382             }
 383             ast::ItemKind::Mod(ref module) => {
 384                 let is_inline = !is_mod_decl(item);
 385                 self.format_missing_with_indent(source!(self, item.span).lo());
 386                 self.format_mod(module, &item.vis, item.span, item.ident, attrs, is_inline);
 387             }
 388             ast::ItemKind::Mac(ref mac) => {
 389                 self.visit_mac(mac, Some(item.ident), MacroPosition::Item);
 390             }
 391             ast::ItemKind::ForeignMod(ref foreign_mod) => {
 392                 self.format_missing_with_indent(source!(self, item.span).lo());
 393                 self.format_foreign_mod(foreign_mod, item.span);
 394             }
 395             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => {
 396                 self.visit_static(&StaticParts::from_item(item));
 397             }
 398             ast::ItemKind::Fn(ref decl, fn_header, ref generics, ref body) => {
 399                 let inner_attrs = inner_attributes(&item.attrs);
 400                 self.visit_fn(
 401                     visit::FnKind::ItemFn(item.ident, fn_header, &item.vis, body),
 402                     generics,
 403                     decl,
 404                     item.span,
 405                     ast::Defaultness::Final,
 406                     Some(&inner_attrs),
 407                 )
 408             }
 409             ast::ItemKind::Ty(ref ty, ref generics) => {
 410                 let rewrite = rewrite_type_alias(
 411                     &self.get_context(),
 412                     self.block_indent,
 413                     item.ident,
 414                     ty,
 415                     generics,
 416                     &item.vis,
 417                 );
 418                 self.push_rewrite(item.span, rewrite);
 419             }
 420             ast::ItemKind::Existential(ref generic_bounds, ref generics) => {
 421                 let rewrite = rewrite_existential_type(
 422                     &self.get_context(),
 423                     self.block_indent,
 424                     item.ident,
 425                     generic_bounds,
 426                     generics,
 427                     &item.vis,
 428                 );
 429                 self.push_rewrite(item.span, rewrite);
 430             }
 431             ast::ItemKind::GlobalAsm(..) => {
 432                 let snippet = Some(self.snippet(item.span).to_owned());
 433                 self.push_rewrite(item.span, snippet);
 434             }
 435             ast::ItemKind::MacroDef(ref def) => {
 436                 let rewrite = rewrite_macro_def(
 437                     &self.get_context(),
 438                     self.shape(),
 439                     self.block_indent,
 440                     def,
 441                     item.ident,
 442                     &item.vis,
 443                     item.span,
 444                 );
 445                 self.push_rewrite(item.span, rewrite);
 446             }
 447         }
 448     }
 449
 450     pub fn visit_trait_item(&mut self, ti: &ast::TraitItem) {
 451         skip_out_of_file_lines_range_visitor!(self, ti.span);
 452
 453         if self.visit_attrs(&ti.attrs, ast::AttrStyle::Outer) {
 454             self.push_skipped_with_span(ti.span());
 455             return;
 456         }
 457
 458         match ti.node {
 459             ast::TraitItemKind::Const(..) => self.visit_static(&StaticParts::from_trait_item(ti)),
 460             ast::TraitItemKind::Method(ref sig, None) => {
 461                 let indent = self.block_indent;
 462                 let rewrite =
 463                     self.rewrite_required_fn(indent, ti.ident, sig, &ti.generics, ti.span);
 464                 self.push_rewrite(ti.span, rewrite);
 465             }
 466             ast::TraitItemKind::Method(ref sig, Some(ref body)) => {
 467                 let inner_attrs = inner_attributes(&ti.attrs);
 468                 self.visit_fn(
 469                     visit::FnKind::Method(ti.ident, sig, None, body),
 470                     &ti.generics,
 471                     &sig.decl,
 472                     ti.span,
 473                     ast::Defaultness::Final,
 474                     Some(&inner_attrs),
 475                 );
 476             }
 477             ast::TraitItemKind::Type(ref generic_bounds, ref type_default) => {
 478                 let rewrite = rewrite_associated_type(
 479                     ti.ident,
 480                     type_default.as_ref(),
 481                     Some(generic_bounds),
 482                     &self.get_context(),
 483                     self.block_indent,
 484                 );
 485                 self.push_rewrite(ti.span, rewrite);
 486             }
 487             ast::TraitItemKind::Macro(ref mac) => {
 488                 self.visit_mac(mac, Some(ti.ident), MacroPosition::Item);
 489             }
 490         }
 491     }
 492
 493     pub fn visit_impl_item(&mut self, ii: &ast::ImplItem) {
 494         skip_out_of_file_lines_range_visitor!(self, ii.span);
 495
 496         if self.visit_attrs(&ii.attrs, ast::AttrStyle::Outer) {
 497             self.push_skipped_with_span(ii.span());
 498             return;
 499         }
 500
 501         match ii.node {
 502             ast::ImplItemKind::Method(ref sig, ref body) => {
 503                 let inner_attrs = inner_attributes(&ii.attrs);
 504                 self.visit_fn(
 505                     visit::FnKind::Method(ii.ident, sig, Some(&ii.vis), body),
 506                     &ii.generics,
 507                     &sig.decl,
 508                     ii.span,
 509                     ii.defaultness,
 510                     Some(&inner_attrs),
 511                 );
 512             }
 513             ast::ImplItemKind::Const(..) => self.visit_static(&StaticParts::from_impl_item(ii)),
 514             ast::ImplItemKind::Type(ref ty) => {
 515                 let rewrite = rewrite_associated_impl_type(
 516                     ii.ident,
 517                     ii.defaultness,
 518                     Some(ty),
 519                     &self.get_context(),
 520                     self.block_indent,
 521                 );
 522                 self.push_rewrite(ii.span, rewrite);
 523             }
 524             ast::ImplItemKind::Existential(ref generic_bounds) => {
 525                 let rewrite = rewrite_existential_impl_type(
 526                     &self.get_context(),
 527                     ii.ident,
 528                     generic_bounds,
 529                     self.block_indent,
 530                 );
 531                 self.push_rewrite(ii.span, rewrite);
 532             }
 533             ast::ImplItemKind::Macro(ref mac) => {
 534                 self.visit_mac(mac, Some(ii.ident), MacroPosition::Item);
 535             }
 536         }
 537     }
 538
 539     fn visit_mac(&mut self, mac: &ast::Mac, ident: Option<ast::Ident>, pos: MacroPosition) {
 540         skip_out_of_file_lines_range_visitor!(self, mac.span);
 541
 542         // 1 = ;
 543         let shape = self.shape().sub_width(1).unwrap();
 544         let rewrite = self.with_context(|ctx| rewrite_macro(mac, ident, ctx, shape, pos));
 545         self.push_rewrite(mac.span, rewrite);
 546     }
 547
 548     pub fn push_str(&mut self, s: &str) {
 549         self.line_number += count_newlines(s);
 550         self.buffer.push_str(s);
 551     }
 552
 553     #[cfg_attr(feature = "cargo-clippy", allow(needless_pass_by_value))]
 554     fn push_rewrite_inner(&mut self, span: Span, rewrite: Option<String>) {
 555         if let Some(ref s) = rewrite {
 556             self.push_str(s);
 557         } else {
 558             let snippet = self.snippet(span);
 559             self.push_str(snippet);
 560         }
 561         self.last_pos = source!(self, span).hi();
 562     }
 563
 564     pub fn push_rewrite(&mut self, span: Span, rewrite: Option<String>) {
 565         self.format_missing_with_indent(source!(self, span).lo());
 566         self.push_rewrite_inner(span, rewrite);
 567     }
 568
 569     pub fn push_skipped_with_span(&mut self, span: Span) {
 570         self.format_missing_with_indent(source!(self, span).lo());
 571         let lo = self.line_number + 1;
 572         self.push_rewrite_inner(span, None);
 573         let hi = self.line_number + 1;
 574         self.skipped_range.push((lo, hi));
 575     }
 576
 577     pub fn from_context(ctx: &'a RewriteContext) -> FmtVisitor<'a> {
 578         FmtVisitor::from_source_map(
 579             ctx.parse_session,
 580             ctx.config,
 581             ctx.snippet_provider,
 582             ctx.report.clone(),
 583         )
 584     }
 585
 586     pub(crate) fn from_source_map(
 587         parse_session: &'a ParseSess,
 588         config: &'a Config,
 589         snippet_provider: &'a SnippetProvider,
 590         report: FormatReport,
 591     ) -> FmtVisitor<'a> {
 592         FmtVisitor {
 593             parse_session,
 594             source_map: parse_session.source_map(),
 595             buffer: String::with_capacity(snippet_provider.big_snippet.len() * 2),
 596             last_pos: BytePos(0),
 597             block_indent: Indent::empty(),
 598             config,
 599             is_if_else_block: false,
 600             snippet_provider,
 601             line_number: 0,
 602             skipped_range: vec![],
 603             macro_rewrite_failure: false,
 604             report,
 605         }
 606     }
 607
 608     pub fn opt_snippet(&'b self, span: Span) -> Option<&'a str> {
 609         self.snippet_provider.span_to_snippet(span)
 610     }
 611
 612     pub fn snippet(&'b self, span: Span) -> &'a str {
 613         self.opt_snippet(span).unwrap()
 614     }
 615
 616     // Returns true if we should skip the following item.
 617     pub fn visit_attrs(&mut self, attrs: &[ast::Attribute], style: ast::AttrStyle) -> bool {
 618         for attr in attrs {
 619             if attr.name() == DEPR_SKIP_ANNOTATION {
 620                 let file_name = self.source_map.span_to_filename(attr.span).into();
 621                 self.report.append(
 622                     file_name,
 623                     vec![FormattingError::from_span(
 624                         &attr.span,
 625                         &self.source_map,
 626                         ErrorKind::DeprecatedAttr,
 627                     )],
 628                 );
 629             } else if attr.path.segments[0].ident.to_string() == "rustfmt"
 630                 && (attr.path.segments.len() == 1
 631                     || attr.path.segments[1].ident.to_string() != "skip")
 632             {
 633                 let file_name = self.source_map.span_to_filename(attr.span).into();
 634                 self.report.append(
 635                     file_name,
 636                     vec![FormattingError::from_span(
 637                         &attr.span,
 638                         &self.source_map,
 639                         ErrorKind::BadAttr,
 640                     )],
 641                 );
 642             }
 643         }
 644         if contains_skip(attrs) {
 645             return true;
 646         }
 647
 648         let attrs: Vec<_> = attrs.iter().filter(|a| a.style == style).cloned().collect();
 649         if attrs.is_empty() {
 650             return false;
 651         }
 652
 653         let rewrite = attrs.rewrite(&self.get_context(), self.shape());
 654         let span = mk_sp(attrs[0].span.lo(), attrs[attrs.len() - 1].span.hi());
 655         self.push_rewrite(span, rewrite);
 656
 657         false
 658     }
 659
 660     fn walk_mod_items(&mut self, m: &ast::Mod) {
 661         self.visit_items_with_reordering(&ptr_vec_to_ref_vec(&m.items));
 662     }
 663
 664     fn walk_stmts(&mut self, stmts: &[ast::Stmt]) {
 665         fn to_stmt_item(stmt: &ast::Stmt) -> Option<&ast::Item> {
 666             match stmt.node {
 667                 ast::StmtKind::Item(ref item) => Some(&**item),
 668                 _ => None,
 669             }
 670         }
 671
 672         if stmts.is_empty() {
 673             return;
 674         }
 675
 676         // Extract leading `use ...;`.
 677         let items: Vec<_> = stmts
 678             .iter()
 679             .take_while(|stmt| to_stmt_item(stmt).map_or(false, is_use_item))
 680             .filter_map(|stmt| to_stmt_item(stmt))
 681             .collect();
 682
 683         if items.is_empty() {
 684             self.visit_stmt(&stmts[0]);
 685             self.walk_stmts(&stmts[1..]);
 686         } else {
 687             self.visit_items_with_reordering(&items);
 688             self.walk_stmts(&stmts[items.len()..]);
 689         }
 690     }
 691
 692     fn walk_block_stmts(&mut self, b: &ast::Block) {
 693         self.walk_stmts(&b.stmts)
 694     }
 695
 696     fn format_mod(
 697         &mut self,
 698         m: &ast::Mod,
 699         vis: &ast::Visibility,
 700         s: Span,
 701         ident: ast::Ident,
 702         attrs: &[ast::Attribute],
 703         is_internal: bool,
 704     ) {
 705         let vis_str = utils::format_visibility(&self.get_context(), vis);
 706         self.push_str(&*vis_str);
 707         self.push_str("mod ");
 708         // Calling `to_owned()` to work around borrow checker.
 709         let ident_str = rewrite_ident(&self.get_context(), ident).to_owned();
 710         self.push_str(&ident_str);
 711
 712         if is_internal {
 713             match self.config.brace_style() {
 714                 BraceStyle::AlwaysNextLine => {
 715                     let indent_str = self.block_indent.to_string_with_newline(self.config);
 716                     self.push_str(&indent_str);
 717                     self.push_str("{");
 718                 }
 719                 _ => self.push_str(" {"),
 720             }
 721             // Hackery to account for the closing }.
 722             let mod_lo = self.snippet_provider.span_after(source!(self, s), "{");
 723             let body_snippet =
 724                 self.snippet(mk_sp(mod_lo, source!(self, m.inner).hi() - BytePos(1)));
 725             let body_snippet = body_snippet.trim();
 726             if body_snippet.is_empty() {
 727                 self.push_str("}");
 728             } else {
 729                 self.last_pos = mod_lo;
 730                 self.block_indent = self.block_indent.block_indent(self.config);
 731                 self.visit_attrs(attrs, ast::AttrStyle::Inner);
 732                 self.walk_mod_items(m);
 733                 self.format_missing_with_indent(source!(self, m.inner).hi() - BytePos(1));
 734                 self.close_block(false);
 735             }
 736             self.last_pos = source!(self, m.inner).hi();
 737         } else {
 738             self.push_str(";");
 739             self.last_pos = source!(self, s).hi();
 740         }
 741     }
 742
 743     pub fn format_separate_mod(&mut self, m: &ast::Mod, source_file: &source_map::SourceFile) {
 744         self.block_indent = Indent::empty();
 745         self.walk_mod_items(m);
 746         self.format_missing_with_indent(source_file.end_pos);
 747     }
 748
 749     pub fn skip_empty_lines(&mut self, end_pos: BytePos) {
 750         while let Some(pos) = self
 751             .snippet_provider
 752             .opt_span_after(mk_sp(self.last_pos, end_pos), "\n")
 753         {
 754             if let Some(snippet) = self.opt_snippet(mk_sp(self.last_pos, pos)) {
 755                 if snippet.trim().is_empty() {
 756                     self.last_pos = pos;
 757                 } else {
 758                     return;
 759                 }
 760             }
 761         }
 762     }
 763
 764     pub fn with_context<F>(&mut self, f: F) -> Option<String>
 765     where
 766         F: Fn(&RewriteContext) -> Option<String>,
 767     {
 768         let result;
 769         let macro_rewrite_failure = {
 770             let context = self.get_context();
 771             result = f(&context);
 772             unsafe { *context.macro_rewrite_failure.as_ptr() }
 773         };
 774         self.macro_rewrite_failure |= macro_rewrite_failure;
 775         result
 776     }
 777
 778     pub fn get_context(&self) -> RewriteContext {
 779         RewriteContext {
 780             parse_session: self.parse_session,
 781             source_map: self.source_map,
 782             config: self.config,
 783             inside_macro: RefCell::new(false),
 784             use_block: RefCell::new(false),
 785             is_if_else_block: RefCell::new(false),
 786             force_one_line_chain: RefCell::new(false),
 787             snippet_provider: self.snippet_provider,
 788             macro_rewrite_failure: RefCell::new(false),
 789             report: self.report.clone(),
 790         }
 791     }
 792 }