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,
18 NodeId, Path, Visibility, VisibilityKind,
21 use syntax::source_map::{BytePos, Span, NO_EXPANSION};
24 use comment::{filter_normal_code, CharClasses, FullCodeCharKind, LineClasses};
25 use config::{Config, Version};
26 use rewrite::RewriteContext;
27 use shape::{Indent, Shape};
29 use unicode_width::UnicodeWidthStr;
31 pub const DEPR_SKIP_ANNOTATION: &str = "rustfmt_skip";
32 pub const SKIP_ANNOTATION: &str = "rustfmt::skip";
34 pub fn rewrite_ident<'a>(context: &'a RewriteContext, ident: ast::Ident) -> &'a str {
35 context.snippet(ident.span)
38 // Computes the length of a string's last line, minus offset.
39 pub fn extra_offset(text: &str, shape: Shape) -> usize {
40 match text.rfind('\n') {
41 // 1 for newline character
42 Some(idx) => text.len().saturating_sub(idx + 1 + shape.used_width()),
47 pub fn is_same_visibility(a: &Visibility, b: &Visibility) -> bool {
48 match (&a.node, &b.node) {
50 VisibilityKind::Restricted { path: p, .. },
51 VisibilityKind::Restricted { path: q, .. },
52 ) => p.to_string() == q.to_string(),
53 (VisibilityKind::Public, VisibilityKind::Public)
54 | (VisibilityKind::Inherited, VisibilityKind::Inherited)
56 VisibilityKind::Crate(CrateSugar::PubCrate),
57 VisibilityKind::Crate(CrateSugar::PubCrate),
60 VisibilityKind::Crate(CrateSugar::JustCrate),
61 VisibilityKind::Crate(CrateSugar::JustCrate),
67 // Uses Cow to avoid allocating in the common cases.
68 pub fn format_visibility(context: &RewriteContext, vis: &Visibility) -> Cow<'static, str> {
70 VisibilityKind::Public => Cow::from("pub "),
71 VisibilityKind::Inherited => Cow::from(""),
72 VisibilityKind::Crate(CrateSugar::PubCrate) => Cow::from("pub(crate) "),
73 VisibilityKind::Crate(CrateSugar::JustCrate) => Cow::from("crate "),
74 VisibilityKind::Restricted { ref path, .. } => {
75 let Path { ref segments, .. } = **path;
76 let mut segments_iter = segments.iter().map(|seg| rewrite_ident(context, seg.ident));
80 .expect("Non-global path in pub(restricted)?");
82 let is_keyword = |s: &str| s == "self" || s == "super";
83 let path = segments_iter.collect::<Vec<_>>().join("::");
84 let in_str = if is_keyword(&path) { "" } else { "in " };
86 Cow::from(format!("pub({}{}) ", in_str, path))
92 pub fn format_async(is_async: ast::IsAsync) -> &'static str {
94 ast::IsAsync::Async { .. } => "async ",
95 ast::IsAsync::NotAsync => "",
100 pub fn format_constness(constness: ast::Constness) -> &'static str {
102 ast::Constness::Const => "const ",
103 ast::Constness::NotConst => "",
108 pub fn format_defaultness(defaultness: ast::Defaultness) -> &'static str {
110 ast::Defaultness::Default => "default ",
111 ast::Defaultness::Final => "",
116 pub fn format_unsafety(unsafety: ast::Unsafety) -> &'static str {
118 ast::Unsafety::Unsafe => "unsafe ",
119 ast::Unsafety::Normal => "",
124 pub fn format_auto(is_auto: ast::IsAuto) -> &'static str {
126 ast::IsAuto::Yes => "auto ",
127 ast::IsAuto::No => "",
132 pub fn format_mutability(mutability: ast::Mutability) -> &'static str {
134 ast::Mutability::Mutable => "mut ",
135 ast::Mutability::Immutable => "",
140 pub fn format_abi(abi: abi::Abi, explicit_abi: bool, is_mod: bool) -> Cow<'static, str> {
141 if abi == abi::Abi::Rust && !is_mod {
143 } else if abi == abi::Abi::C && !explicit_abi {
146 Cow::from(format!("extern {} ", abi))
151 // Transform `Vec<syntax::ptr::P<T>>` into `Vec<&T>`
152 pub fn ptr_vec_to_ref_vec<T>(vec: &[ptr::P<T>]) -> Vec<&T> {
153 vec.iter().map(|x| &**x).collect::<Vec<_>>()
157 pub fn filter_attributes(attrs: &[ast::Attribute], style: ast::AttrStyle) -> Vec<ast::Attribute> {
160 .filter(|a| a.style == style)
166 pub fn inner_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
167 filter_attributes(attrs, ast::AttrStyle::Inner)
171 pub fn outer_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
172 filter_attributes(attrs, ast::AttrStyle::Outer)
176 pub fn is_single_line(s: &str) -> bool {
177 s.chars().find(|&c| c == '\n').is_none()
181 pub fn first_line_contains_single_line_comment(s: &str) -> bool {
182 s.lines().next().map_or(false, |l| l.contains("//"))
186 pub fn last_line_contains_single_line_comment(s: &str) -> bool {
187 s.lines().last().map_or(false, |l| l.contains("//"))
191 pub fn is_attributes_extendable(attrs_str: &str) -> bool {
192 !attrs_str.contains('\n') && !last_line_contains_single_line_comment(attrs_str)
195 // The width of the first line in s.
197 pub fn first_line_width(s: &str) -> usize {
198 unicode_str_width(s.splitn(2, '\n').next().unwrap_or(""))
201 // The width of the last line in s.
203 pub fn last_line_width(s: &str) -> usize {
204 unicode_str_width(s.rsplitn(2, '\n').next().unwrap_or(""))
207 // The total used width of the last line.
209 pub fn last_line_used_width(s: &str, offset: usize) -> usize {
210 if s.contains('\n') {
213 offset + unicode_str_width(s)
218 pub fn trimmed_last_line_width(s: &str) -> usize {
219 unicode_str_width(match s.rfind('\n') {
220 Some(n) => s[(n + 1)..].trim(),
226 pub fn last_line_extendable(s: &str) -> bool {
227 if s.ends_with("\"#") {
230 for c in s.chars().rev() {
232 '(' | ')' | ']' | '}' | '?' | '>' => continue,
234 _ if c.is_whitespace() => continue,
242 fn is_skip(meta_item: &MetaItem) -> bool {
243 match meta_item.node {
244 MetaItemKind::Word => {
245 let path_str = meta_item.ident.to_string();
246 path_str == SKIP_ANNOTATION || path_str == DEPR_SKIP_ANNOTATION
248 MetaItemKind::List(ref l) => {
249 meta_item.name() == "cfg_attr" && l.len() == 2 && is_skip_nested(&l[1])
256 fn is_skip_nested(meta_item: &NestedMetaItem) -> bool {
257 match meta_item.node {
258 NestedMetaItemKind::MetaItem(ref mi) => is_skip(mi),
259 NestedMetaItemKind::Literal(_) => false,
264 pub fn contains_skip(attrs: &[Attribute]) -> bool {
267 .any(|a| a.meta().map_or(false, |a| is_skip(&a)))
271 pub fn semicolon_for_expr(context: &RewriteContext, expr: &ast::Expr) -> bool {
273 ast::ExprKind::Ret(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Break(..) => {
274 context.config.trailing_semicolon()
281 pub fn semicolon_for_stmt(context: &RewriteContext, stmt: &ast::Stmt) -> bool {
283 ast::StmtKind::Semi(ref expr) => match expr.node {
284 ast::ExprKind::While(..)
285 | ast::ExprKind::WhileLet(..)
286 | ast::ExprKind::Loop(..)
287 | ast::ExprKind::ForLoop(..) => false,
288 ast::ExprKind::Break(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Ret(..) => {
289 context.config.trailing_semicolon()
293 ast::StmtKind::Expr(..) => false,
299 pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
301 ast::StmtKind::Expr(ref expr) => Some(expr),
307 pub fn count_newlines(input: &str) -> usize {
308 // Using bytes to omit UTF-8 decoding
309 bytecount::count(input.as_bytes(), b'\n')
312 // For format_missing and last_pos, need to use the source callsite (if applicable).
313 // Required as generated code spans aren't guaranteed to follow on from the last span.
314 macro_rules! source {
315 ($this:ident, $sp:expr) => {
316 $sp.source_callsite()
320 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
321 Span::new(lo, hi, NO_EXPANSION)
324 // Return true if the given span does not intersect with file lines.
325 macro_rules! out_of_file_lines_range {
326 ($self:ident, $span:expr) => {
327 !$self.config.file_lines().is_all()
331 .intersects(&$self.source_map.lookup_line_range($span))
335 macro_rules! skip_out_of_file_lines_range {
336 ($self:ident, $span:expr) => {
337 if out_of_file_lines_range!($self, $span) {
343 macro_rules! skip_out_of_file_lines_range_visitor {
344 ($self:ident, $span:expr) => {
345 if out_of_file_lines_range!($self, $span) {
346 $self.push_rewrite($span, None);
352 // Wraps String in an Option. Returns Some when the string adheres to the
353 // Rewrite constraints defined for the Rewrite trait and None otherwise.
354 pub fn wrap_str(s: String, max_width: usize, shape: Shape) -> Option<String> {
355 if is_valid_str(&filter_normal_code(&s), max_width, shape) {
362 fn is_valid_str(snippet: &str, max_width: usize, shape: Shape) -> bool {
363 if !snippet.is_empty() {
364 // First line must fits with `shape.width`.
365 if first_line_width(snippet) > shape.width {
368 // If the snippet does not include newline, we are done.
369 if is_single_line(snippet) {
372 // The other lines must fit within the maximum width.
376 .any(|line| unicode_str_width(line) > max_width)
380 // A special check for the last line, since the caller may
381 // place trailing characters on this line.
382 if last_line_width(snippet) > shape.used_width() + shape.width {
390 pub fn colon_spaces(before: bool, after: bool) -> &'static str {
391 match (before, after) {
392 (true, true) => " : ",
393 (true, false) => " :",
394 (false, true) => ": ",
395 (false, false) => ":",
400 pub fn left_most_sub_expr(e: &ast::Expr) -> &ast::Expr {
402 ast::ExprKind::Call(ref e, _)
403 | ast::ExprKind::Binary(_, ref e, _)
404 | ast::ExprKind::Cast(ref e, _)
405 | ast::ExprKind::Type(ref e, _)
406 | ast::ExprKind::Assign(ref e, _)
407 | ast::ExprKind::AssignOp(_, ref e, _)
408 | ast::ExprKind::Field(ref e, _)
409 | ast::ExprKind::Index(ref e, _)
410 | ast::ExprKind::Range(Some(ref e), _, _)
411 | ast::ExprKind::Try(ref e) => left_most_sub_expr(e),
417 pub fn starts_with_newline(s: &str) -> bool {
418 s.starts_with('\n') || s.starts_with("\r\n")
422 pub fn first_line_ends_with(s: &str, c: char) -> bool {
423 s.lines().next().map_or(false, |l| l.ends_with(c))
426 // States whether an expression's last line exclusively consists of closing
427 // parens, braces, and brackets in its idiomatic formatting.
428 pub fn is_block_expr(context: &RewriteContext, expr: &ast::Expr, repr: &str) -> bool {
430 ast::ExprKind::Mac(..)
431 | ast::ExprKind::Call(..)
432 | ast::ExprKind::MethodCall(..)
433 | ast::ExprKind::Array(..)
434 | ast::ExprKind::Struct(..)
435 | ast::ExprKind::While(..)
436 | ast::ExprKind::WhileLet(..)
437 | ast::ExprKind::If(..)
438 | ast::ExprKind::IfLet(..)
439 | ast::ExprKind::Block(..)
440 | ast::ExprKind::Loop(..)
441 | ast::ExprKind::ForLoop(..)
442 | ast::ExprKind::Match(..) => repr.contains('\n'),
443 ast::ExprKind::Paren(ref expr)
444 | ast::ExprKind::Binary(_, _, ref expr)
445 | ast::ExprKind::Index(_, ref expr)
446 | ast::ExprKind::Unary(_, ref expr)
447 | ast::ExprKind::Closure(_, _, _, _, ref expr, _)
448 | ast::ExprKind::Try(ref expr)
449 | ast::ExprKind::Yield(Some(ref expr)) => is_block_expr(context, expr, repr),
450 // This can only be a string lit
451 ast::ExprKind::Lit(_) => {
452 repr.contains('\n') && trimmed_last_line_width(repr) <= context.config.tab_spaces()
458 /// Remove trailing spaces from the specified snippet. We do not remove spaces
459 /// inside strings or comments.
460 pub fn remove_trailing_white_spaces(text: &str) -> String {
461 let mut buffer = String::with_capacity(text.len());
462 let mut space_buffer = String::with_capacity(128);
463 for (char_kind, c) in CharClasses::new(text.chars()) {
466 if char_kind == FullCodeCharKind::InString {
467 buffer.push_str(&space_buffer);
469 space_buffer.clear();
472 _ if c.is_whitespace() => {
473 space_buffer.push(c);
476 if !space_buffer.is_empty() {
477 buffer.push_str(&space_buffer);
478 space_buffer.clear();
487 /// Indent each line according to the specified `indent`.
515 pub fn trim_left_preserve_layout(orig: &str, indent: Indent, config: &Config) -> Option<String> {
516 let mut lines = LineClasses::new(orig);
517 let first_line = lines.next().map(|(_, s)| s.trim_end().to_owned())?;
518 let mut trimmed_lines = Vec::with_capacity(16);
520 let mut veto_trim = false;
521 let min_prefix_space_width = lines
522 .filter_map(|(kind, line)| {
523 let mut trimmed = true;
524 let prefix_space_width = if is_empty_line(&line) {
527 Some(get_prefix_space_width(config, &line))
530 let new_veto_trim_value = (kind.is_string()
531 || (config.version() == Version::Two && kind.is_commented_string()))
532 && !line.ends_with('\\');
533 let line = if veto_trim || new_veto_trim_value {
534 veto_trim = new_veto_trim_value;
538 line.trim().to_owned()
540 trimmed_lines.push((trimmed, line, prefix_space_width));
542 // Because there is a veto against trimming and indenting lines within a string,
543 // such lines should not be taken into account when computing the minimum.
545 FullCodeCharKind::InStringCommented | FullCodeCharKind::EndStringCommented
546 if config.version() == Version::Two =>
550 FullCodeCharKind::InString | FullCodeCharKind::EndString => None,
551 _ => prefix_space_width,
562 |&(trimmed, ref line, prefix_space_width)| match prefix_space_width {
563 _ if !trimmed => line.to_owned(),
564 Some(original_indent_width) => {
565 let new_indent_width = indent.width()
566 + original_indent_width.saturating_sub(min_prefix_space_width);
567 let new_indent = Indent::from_width(config, new_indent_width);
568 format!("{}{}", new_indent.to_string(config), line)
570 None => String::new(),
578 pub fn is_empty_line(s: &str) -> bool {
579 s.is_empty() || s.chars().all(char::is_whitespace)
582 fn get_prefix_space_width(config: &Config, s: &str) -> usize {
587 '\t' => width += config.tab_spaces(),
594 pub(crate) trait NodeIdExt {
598 impl NodeIdExt for NodeId {
599 fn root() -> NodeId {
600 NodeId::placeholder_from_mark(Mark::root())
604 pub(crate) fn unicode_str_width(s: &str) -> usize {
613 fn test_remove_trailing_white_spaces() {
614 let s = " r#\"\n test\n \"#";
615 assert_eq!(remove_trailing_white_spaces(&s), s);
619 fn test_trim_left_preserve_layout() {
620 let s = "aaa\n\tbbb\n ccc";
621 let config = Config::default();
622 let indent = Indent::new(4, 0);
624 trim_left_preserve_layout(&s, indent, &config),
625 Some("aaa\n bbb\n ccc".to_string())