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.
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.
15 use rustc_target::spec::abi;
17 self, Attribute, CrateSugar, MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind, Path,
18 Visibility, VisibilityKind,
21 use syntax::source_map::{BytePos, Span, NO_EXPANSION};
23 use comment::{filter_normal_code, CharClasses, FullCodeCharKind, LineClasses};
25 use rewrite::RewriteContext;
26 use shape::{Indent, Shape};
28 pub const DEPR_SKIP_ANNOTATION: &str = "rustfmt_skip";
29 pub const SKIP_ANNOTATION: &str = "rustfmt::skip";
31 pub fn rewrite_ident<'a>(context: &'a RewriteContext, ident: ast::Ident) -> &'a str {
32 context.snippet(ident.span)
35 // Computes the length of a string's last line, minus offset.
36 pub fn extra_offset(text: &str, shape: Shape) -> usize {
37 match text.rfind('\n') {
38 // 1 for newline character
39 Some(idx) => text.len().saturating_sub(idx + 1 + shape.used_width()),
44 pub fn is_same_visibility(a: &Visibility, b: &Visibility) -> bool {
45 match (&a.node, &b.node) {
47 VisibilityKind::Restricted { path: p, .. },
48 VisibilityKind::Restricted { path: q, .. },
49 ) => p.to_string() == q.to_string(),
50 (VisibilityKind::Public, VisibilityKind::Public)
51 | (VisibilityKind::Inherited, VisibilityKind::Inherited)
53 VisibilityKind::Crate(CrateSugar::PubCrate),
54 VisibilityKind::Crate(CrateSugar::PubCrate),
57 VisibilityKind::Crate(CrateSugar::JustCrate),
58 VisibilityKind::Crate(CrateSugar::JustCrate),
64 // Uses Cow to avoid allocating in the common cases.
65 pub fn format_visibility(context: &RewriteContext, vis: &Visibility) -> Cow<'static, str> {
67 VisibilityKind::Public => Cow::from("pub "),
68 VisibilityKind::Inherited => Cow::from(""),
69 VisibilityKind::Crate(CrateSugar::PubCrate) => Cow::from("pub(crate) "),
70 VisibilityKind::Crate(CrateSugar::JustCrate) => Cow::from("crate "),
71 VisibilityKind::Restricted { ref path, .. } => {
72 let Path { ref segments, .. } = **path;
73 let mut segments_iter = segments.iter().map(|seg| rewrite_ident(context, seg.ident));
77 .expect("Non-global path in pub(restricted)?");
79 let is_keyword = |s: &str| s == "self" || s == "super";
80 let path = segments_iter.collect::<Vec<_>>().join("::");
81 let in_str = if is_keyword(&path) { "" } else { "in " };
83 Cow::from(format!("pub({}{}) ", in_str, path))
89 pub fn format_async(is_async: ast::IsAsync) -> &'static str {
91 ast::IsAsync::Async { .. } => "async ",
92 ast::IsAsync::NotAsync => "",
97 pub fn format_constness(constness: ast::Constness) -> &'static str {
99 ast::Constness::Const => "const ",
100 ast::Constness::NotConst => "",
105 pub fn format_defaultness(defaultness: ast::Defaultness) -> &'static str {
107 ast::Defaultness::Default => "default ",
108 ast::Defaultness::Final => "",
113 pub fn format_unsafety(unsafety: ast::Unsafety) -> &'static str {
115 ast::Unsafety::Unsafe => "unsafe ",
116 ast::Unsafety::Normal => "",
121 pub fn format_auto(is_auto: ast::IsAuto) -> &'static str {
123 ast::IsAuto::Yes => "auto ",
124 ast::IsAuto::No => "",
129 pub fn format_mutability(mutability: ast::Mutability) -> &'static str {
131 ast::Mutability::Mutable => "mut ",
132 ast::Mutability::Immutable => "",
137 pub fn format_abi(abi: abi::Abi, explicit_abi: bool, is_mod: bool) -> Cow<'static, str> {
138 if abi == abi::Abi::Rust && !is_mod {
140 } else if abi == abi::Abi::C && !explicit_abi {
143 Cow::from(format!("extern {} ", abi))
148 // Transform `Vec<syntax::ptr::P<T>>` into `Vec<&T>`
149 pub fn ptr_vec_to_ref_vec<T>(vec: &[ptr::P<T>]) -> Vec<&T> {
150 vec.iter().map(|x| &**x).collect::<Vec<_>>()
154 pub fn filter_attributes(attrs: &[ast::Attribute], style: ast::AttrStyle) -> Vec<ast::Attribute> {
157 .filter(|a| a.style == style)
163 pub fn inner_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
164 filter_attributes(attrs, ast::AttrStyle::Inner)
168 pub fn outer_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
169 filter_attributes(attrs, ast::AttrStyle::Outer)
173 pub fn is_single_line(s: &str) -> bool {
174 s.chars().find(|&c| c == '\n').is_none()
178 pub fn first_line_contains_single_line_comment(s: &str) -> bool {
179 s.lines().next().map_or(false, |l| l.contains("//"))
183 pub fn last_line_contains_single_line_comment(s: &str) -> bool {
184 s.lines().last().map_or(false, |l| l.contains("//"))
188 pub fn is_attributes_extendable(attrs_str: &str) -> bool {
189 !attrs_str.contains('\n') && !last_line_contains_single_line_comment(attrs_str)
192 // The width of the first line in s.
194 pub fn first_line_width(s: &str) -> usize {
201 // The width of the last line in s.
203 pub fn last_line_width(s: &str) -> usize {
204 match s.rfind('\n') {
205 Some(n) => s.len() - n - 1,
210 // The total used width of the last line.
212 pub fn last_line_used_width(s: &str, offset: usize) -> usize {
213 if s.contains('\n') {
221 pub fn trimmed_last_line_width(s: &str) -> usize {
222 match s.rfind('\n') {
223 Some(n) => s[(n + 1)..].trim().len(),
224 None => s.trim().len(),
229 pub fn last_line_extendable(s: &str) -> bool {
230 if s.ends_with("\"#") {
233 for c in s.chars().rev() {
235 '(' | ')' | ']' | '}' | '?' | '>' => continue,
237 _ if c.is_whitespace() => continue,
245 fn is_skip(meta_item: &MetaItem) -> bool {
246 match meta_item.node {
247 MetaItemKind::Word => {
248 let path_str = meta_item.ident.to_string();
249 path_str == SKIP_ANNOTATION || path_str == DEPR_SKIP_ANNOTATION
251 MetaItemKind::List(ref l) => {
252 meta_item.name() == "cfg_attr" && l.len() == 2 && is_skip_nested(&l[1])
259 fn is_skip_nested(meta_item: &NestedMetaItem) -> bool {
260 match meta_item.node {
261 NestedMetaItemKind::MetaItem(ref mi) => is_skip(mi),
262 NestedMetaItemKind::Literal(_) => false,
267 pub fn contains_skip(attrs: &[Attribute]) -> bool {
270 .any(|a| a.meta().map_or(false, |a| is_skip(&a)))
274 pub fn semicolon_for_expr(context: &RewriteContext, expr: &ast::Expr) -> bool {
276 ast::ExprKind::Ret(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Break(..) => {
277 context.config.trailing_semicolon()
284 pub fn semicolon_for_stmt(context: &RewriteContext, stmt: &ast::Stmt) -> bool {
286 ast::StmtKind::Semi(ref expr) => match expr.node {
287 ast::ExprKind::While(..)
288 | ast::ExprKind::WhileLet(..)
289 | ast::ExprKind::Loop(..)
290 | ast::ExprKind::ForLoop(..) => false,
291 ast::ExprKind::Break(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Ret(..) => {
292 context.config.trailing_semicolon()
296 ast::StmtKind::Expr(..) => false,
302 pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
304 ast::StmtKind::Expr(ref expr) => Some(expr),
310 pub fn count_newlines(input: &str) -> usize {
311 // Using bytes to omit UTF-8 decoding
312 bytecount::count(input.as_bytes(), b'\n')
315 // For format_missing and last_pos, need to use the source callsite (if applicable).
316 // Required as generated code spans aren't guaranteed to follow on from the last span.
317 macro_rules! source {
318 ($this:ident, $sp:expr) => {
319 $sp.source_callsite()
323 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
324 Span::new(lo, hi, NO_EXPANSION)
327 // Return true if the given span does not intersect with file lines.
328 macro_rules! out_of_file_lines_range {
329 ($self:ident, $span:expr) => {
330 !$self.config.file_lines().is_all()
334 .intersects(&$self.source_map.lookup_line_range($span))
338 macro_rules! skip_out_of_file_lines_range {
339 ($self:ident, $span:expr) => {
340 if out_of_file_lines_range!($self, $span) {
346 macro_rules! skip_out_of_file_lines_range_visitor {
347 ($self:ident, $span:expr) => {
348 if out_of_file_lines_range!($self, $span) {
349 $self.push_rewrite($span, None);
355 // Wraps String in an Option. Returns Some when the string adheres to the
356 // Rewrite constraints defined for the Rewrite trait and None otherwise.
357 pub fn wrap_str(s: String, max_width: usize, shape: Shape) -> Option<String> {
358 if is_valid_str(&filter_normal_code(&s), max_width, shape) {
365 fn is_valid_str(snippet: &str, max_width: usize, shape: Shape) -> bool {
366 if !snippet.is_empty() {
367 // First line must fits with `shape.width`.
368 if first_line_width(snippet) > shape.width {
371 // If the snippet does not include newline, we are done.
372 if first_line_width(snippet) == snippet.len() {
375 // The other lines must fit within the maximum width.
376 if snippet.lines().skip(1).any(|line| line.len() > max_width) {
379 // A special check for the last line, since the caller may
380 // place trailing characters on this line.
381 if last_line_width(snippet) > shape.used_width() + shape.width {
389 pub fn colon_spaces(before: bool, after: bool) -> &'static str {
390 match (before, after) {
391 (true, true) => " : ",
392 (true, false) => " :",
393 (false, true) => ": ",
394 (false, false) => ":",
399 pub fn left_most_sub_expr(e: &ast::Expr) -> &ast::Expr {
401 ast::ExprKind::Call(ref e, _)
402 | ast::ExprKind::Binary(_, ref e, _)
403 | ast::ExprKind::Cast(ref e, _)
404 | ast::ExprKind::Type(ref e, _)
405 | ast::ExprKind::Assign(ref e, _)
406 | ast::ExprKind::AssignOp(_, ref e, _)
407 | ast::ExprKind::Field(ref e, _)
408 | ast::ExprKind::Index(ref e, _)
409 | ast::ExprKind::Range(Some(ref e), _, _)
410 | ast::ExprKind::Try(ref e) => left_most_sub_expr(e),
416 pub fn starts_with_newline(s: &str) -> bool {
417 s.starts_with('\n') || s.starts_with("\r\n")
421 pub fn first_line_ends_with(s: &str, c: char) -> bool {
422 s.lines().next().map_or(false, |l| l.ends_with(c))
425 // States whether an expression's last line exclusively consists of closing
426 // parens, braces, and brackets in its idiomatic formatting.
427 pub fn is_block_expr(context: &RewriteContext, expr: &ast::Expr, repr: &str) -> bool {
429 ast::ExprKind::Mac(..)
430 | ast::ExprKind::Call(..)
431 | ast::ExprKind::MethodCall(..)
432 | ast::ExprKind::Array(..)
433 | ast::ExprKind::Struct(..)
434 | ast::ExprKind::While(..)
435 | ast::ExprKind::WhileLet(..)
436 | ast::ExprKind::If(..)
437 | ast::ExprKind::IfLet(..)
438 | ast::ExprKind::Block(..)
439 | ast::ExprKind::Loop(..)
440 | ast::ExprKind::ForLoop(..)
441 | ast::ExprKind::Match(..) => repr.contains('\n'),
442 ast::ExprKind::Paren(ref expr)
443 | ast::ExprKind::Binary(_, _, ref expr)
444 | ast::ExprKind::Index(_, ref expr)
445 | ast::ExprKind::Unary(_, ref expr)
446 | ast::ExprKind::Closure(_, _, _, _, ref expr, _)
447 | ast::ExprKind::Try(ref expr)
448 | ast::ExprKind::Yield(Some(ref expr)) => is_block_expr(context, expr, repr),
449 // This can only be a string lit
450 ast::ExprKind::Lit(_) => {
451 repr.contains('\n') && trimmed_last_line_width(repr) <= context.config.tab_spaces()
457 /// Remove trailing spaces from the specified snippet. We do not remove spaces
458 /// inside strings or comments.
459 pub fn remove_trailing_white_spaces(text: &str) -> String {
460 let mut buffer = String::with_capacity(text.len());
461 let mut space_buffer = String::with_capacity(128);
462 for (char_kind, c) in CharClasses::new(text.chars()) {
465 if char_kind == FullCodeCharKind::InString {
466 buffer.push_str(&space_buffer);
468 space_buffer.clear();
471 _ if c.is_whitespace() => {
472 space_buffer.push(c);
475 if !space_buffer.is_empty() {
476 buffer.push_str(&space_buffer);
477 space_buffer.clear();
486 /// Indent each line according to the specified `indent`.
514 pub fn trim_left_preserve_layout(orig: &str, indent: Indent, config: &Config) -> Option<String> {
515 let mut lines = LineClasses::new(orig);
516 let first_line = lines.next().map(|(_, s)| s.trim_right().to_owned())?;
517 let mut trimmed_lines = Vec::with_capacity(16);
519 let mut veto_trim = false;
520 let min_prefix_space_width = lines
521 .filter_map(|(kind, line)| {
522 let mut trimmed = true;
523 let prefix_space_width = if is_empty_line(&line) {
526 Some(get_prefix_space_width(config, &line))
529 let line = if veto_trim || (kind.is_string() && !line.ends_with('\\')) {
530 veto_trim = kind.is_string() && !line.ends_with('\\');
534 line.trim().to_owned()
536 trimmed_lines.push((trimmed, line, prefix_space_width));
538 // When computing the minimum, do not consider lines within a string.
539 // The reason is there is a veto against trimming and indenting such lines
541 FullCodeCharKind::InString | FullCodeCharKind::EndString => None,
542 _ => prefix_space_width,
553 |&(trimmed, ref line, prefix_space_width)| match prefix_space_width {
554 _ if !trimmed => line.to_owned(),
555 Some(original_indent_width) => {
556 let new_indent_width = indent.width()
557 + original_indent_width.saturating_sub(min_prefix_space_width);
558 let new_indent = Indent::from_width(config, new_indent_width);
559 format!("{}{}", new_indent.to_string(config), line)
561 None => String::new(),
569 pub fn is_empty_line(s: &str) -> bool {
570 s.is_empty() || s.chars().all(char::is_whitespace)
573 fn get_prefix_space_width(config: &Config, s: &str) -> usize {
578 '\t' => width += config.tab_spaces(),
590 fn test_remove_trailing_white_spaces() {
591 let s = " r#\"\n test\n \"#";
592 assert_eq!(remove_trailing_white_spaces(&s), s);
596 fn test_trim_left_preserve_layout() {
597 let s = "aaa\n\tbbb\n ccc";
598 let config = Config::default();
599 let indent = Indent::new(4, 0);
601 trim_left_preserve_layout(&s, indent, &config),
602 Some("aaa\n bbb\n ccc".to_string())