4 self, Attribute, MetaItem, MetaItemKind, NestedMetaItem, NodeId, Path, Visibility,
8 use rustc_ast_pretty::pprust;
9 use rustc_span::{sym, symbol, BytePos, LocalExpnId, Span, Symbol, SyntaxContext};
10 use unicode_width::UnicodeWidthStr;
12 use crate::comment::{filter_normal_code, CharClasses, FullCodeCharKind, LineClasses};
13 use crate::config::{Config, Version};
14 use crate::rewrite::RewriteContext;
15 use crate::shape::{Indent, Shape};
18 pub(crate) fn depr_skip_annotation() -> Symbol {
19 Symbol::intern("rustfmt_skip")
23 pub(crate) fn skip_annotation() -> Symbol {
24 Symbol::intern("rustfmt::skip")
27 pub(crate) fn rewrite_ident<'a>(context: &'a RewriteContext<'_>, ident: symbol::Ident) -> &'a str {
28 context.snippet(ident.span)
31 // Computes the length of a string's last line, minus offset.
32 pub(crate) fn extra_offset(text: &str, shape: Shape) -> usize {
33 match text.rfind('\n') {
34 // 1 for newline character
35 Some(idx) => text.len().saturating_sub(idx + 1 + shape.used_width()),
40 pub(crate) fn is_same_visibility(a: &Visibility, b: &Visibility) -> bool {
41 match (&a.kind, &b.kind) {
43 VisibilityKind::Restricted { path: p, .. },
44 VisibilityKind::Restricted { path: q, .. },
45 ) => pprust::path_to_string(p) == pprust::path_to_string(q),
46 (VisibilityKind::Public, VisibilityKind::Public)
47 | (VisibilityKind::Inherited, VisibilityKind::Inherited) => true,
52 // Uses Cow to avoid allocating in the common cases.
53 pub(crate) fn format_visibility(
54 context: &RewriteContext<'_>,
56 ) -> Cow<'static, str> {
58 VisibilityKind::Public => Cow::from("pub "),
59 VisibilityKind::Inherited => Cow::from(""),
60 VisibilityKind::Restricted { ref path, .. } => {
61 let Path { ref segments, .. } = **path;
62 let mut segments_iter = segments.iter().map(|seg| rewrite_ident(context, seg.ident));
66 .expect("Non-global path in pub(restricted)?");
68 let is_keyword = |s: &str| s == "crate" || s == "self" || s == "super";
69 let path = segments_iter.collect::<Vec<_>>().join("::");
70 let in_str = if is_keyword(&path) { "" } else { "in " };
72 Cow::from(format!("pub({}{}) ", in_str, path))
78 pub(crate) fn format_async(is_async: &ast::Async) -> &'static str {
80 ast::Async::Yes { .. } => "async ",
86 pub(crate) fn format_constness(constness: ast::Const) -> &'static str {
88 ast::Const::Yes(..) => "const ",
94 pub(crate) fn format_constness_right(constness: ast::Const) -> &'static str {
96 ast::Const::Yes(..) => " const",
102 pub(crate) fn format_defaultness(defaultness: ast::Defaultness) -> &'static str {
104 ast::Defaultness::Default(..) => "default ",
105 ast::Defaultness::Final => "",
110 pub(crate) fn format_unsafety(unsafety: ast::Unsafe) -> &'static str {
112 ast::Unsafe::Yes(..) => "unsafe ",
113 ast::Unsafe::No => "",
118 pub(crate) fn format_auto(is_auto: ast::IsAuto) -> &'static str {
120 ast::IsAuto::Yes => "auto ",
121 ast::IsAuto::No => "",
126 pub(crate) fn format_mutability(mutability: ast::Mutability) -> &'static str {
128 ast::Mutability::Mut => "mut ",
129 ast::Mutability::Not => "",
134 pub(crate) fn format_extern(
138 ) -> Cow<'static, str> {
139 let abi = match ext {
140 ast::Extern::None => "Rust".to_owned(),
141 ast::Extern::Implicit => "C".to_owned(),
142 ast::Extern::Explicit(abi) => abi.symbol_unescaped.to_string(),
145 if abi == "Rust" && !is_mod {
147 } else if abi == "C" && !explicit_abi {
150 Cow::from(format!(r#"extern "{}" "#, abi))
155 // Transform `Vec<rustc_ast::ptr::P<T>>` into `Vec<&T>`
156 pub(crate) fn ptr_vec_to_ref_vec<T>(vec: &[ptr::P<T>]) -> Vec<&T> {
157 vec.iter().map(|x| &**x).collect::<Vec<_>>()
161 pub(crate) fn filter_attributes(
162 attrs: &[ast::Attribute],
163 style: ast::AttrStyle,
164 ) -> Vec<ast::Attribute> {
167 .filter(|a| a.style == style)
173 pub(crate) fn inner_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
174 filter_attributes(attrs, ast::AttrStyle::Inner)
178 pub(crate) fn outer_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
179 filter_attributes(attrs, ast::AttrStyle::Outer)
183 pub(crate) fn is_single_line(s: &str) -> bool {
184 !s.chars().any(|c| c == '\n')
188 pub(crate) fn first_line_contains_single_line_comment(s: &str) -> bool {
189 s.lines().next().map_or(false, |l| l.contains("//"))
193 pub(crate) fn last_line_contains_single_line_comment(s: &str) -> bool {
194 s.lines().last().map_or(false, |l| l.contains("//"))
198 pub(crate) fn is_attributes_extendable(attrs_str: &str) -> bool {
199 !attrs_str.contains('\n') && !last_line_contains_single_line_comment(attrs_str)
202 /// The width of the first line in s.
204 pub(crate) fn first_line_width(s: &str) -> usize {
205 unicode_str_width(s.splitn(2, '\n').next().unwrap_or(""))
208 /// The width of the last line in s.
210 pub(crate) fn last_line_width(s: &str) -> usize {
211 unicode_str_width(s.rsplitn(2, '\n').next().unwrap_or(""))
214 /// The total used width of the last line.
216 pub(crate) fn last_line_used_width(s: &str, offset: usize) -> usize {
217 if s.contains('\n') {
220 offset + unicode_str_width(s)
225 pub(crate) fn trimmed_last_line_width(s: &str) -> usize {
226 unicode_str_width(match s.rfind('\n') {
227 Some(n) => s[(n + 1)..].trim(),
233 pub(crate) fn last_line_extendable(s: &str) -> bool {
234 if s.ends_with("\"#") {
237 for c in s.chars().rev() {
239 '(' | ')' | ']' | '}' | '?' | '>' => continue,
241 _ if c.is_whitespace() => continue,
249 fn is_skip(meta_item: &MetaItem) -> bool {
250 match meta_item.kind {
251 MetaItemKind::Word => {
252 let path_str = pprust::path_to_string(&meta_item.path);
253 path_str == skip_annotation().as_str() || path_str == depr_skip_annotation().as_str()
255 MetaItemKind::List(ref l) => {
256 meta_item.has_name(sym::cfg_attr) && l.len() == 2 && is_skip_nested(&l[1])
263 fn is_skip_nested(meta_item: &NestedMetaItem) -> bool {
265 NestedMetaItem::MetaItem(ref mi) => is_skip(mi),
266 NestedMetaItem::Literal(_) => false,
271 pub(crate) fn contains_skip(attrs: &[Attribute]) -> bool {
274 .any(|a| a.meta().map_or(false, |a| is_skip(&a)))
278 pub(crate) fn semicolon_for_expr(context: &RewriteContext<'_>, expr: &ast::Expr) -> bool {
279 // Never try to insert semicolons on expressions when we're inside
280 // a macro definition - this can prevent the macro from compiling
281 // when used in expression position
282 if context.is_macro_def {
287 ast::ExprKind::Ret(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Break(..) => {
288 context.config.trailing_semicolon()
295 pub(crate) fn semicolon_for_stmt(context: &RewriteContext<'_>, stmt: &ast::Stmt) -> bool {
297 ast::StmtKind::Semi(ref expr) => match expr.kind {
298 ast::ExprKind::While(..) | ast::ExprKind::Loop(..) | ast::ExprKind::ForLoop(..) => {
301 ast::ExprKind::Break(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Ret(..) => {
302 context.config.trailing_semicolon()
306 ast::StmtKind::Expr(..) => false,
312 pub(crate) fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
314 ast::StmtKind::Expr(ref expr) => Some(expr),
319 /// Returns the number of LF and CRLF respectively.
320 pub(crate) fn count_lf_crlf(input: &str) -> (usize, usize) {
323 let mut is_crlf = false;
324 for c in input.as_bytes() {
326 b'\r' => is_crlf = true,
327 b'\n' if is_crlf => crlf += 1,
329 _ => is_crlf = false,
335 pub(crate) fn count_newlines(input: &str) -> usize {
336 // Using bytes to omit UTF-8 decoding
337 bytecount::count(input.as_bytes(), b'\n')
340 // For format_missing and last_pos, need to use the source callsite (if applicable).
341 // Required as generated code spans aren't guaranteed to follow on from the last span.
342 macro_rules! source {
343 ($this:ident, $sp:expr) => {
344 $sp.source_callsite()
348 pub(crate) fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
349 Span::new(lo, hi, SyntaxContext::root(), None)
352 pub(crate) fn mk_sp_lo_plus_one(lo: BytePos) -> Span {
353 Span::new(lo, lo + BytePos(1), SyntaxContext::root(), None)
356 // Returns `true` if the given span does not intersect with file lines.
357 macro_rules! out_of_file_lines_range {
358 ($self:ident, $span:expr) => {
359 !$self.config.file_lines().is_all()
363 .intersects(&$self.parse_sess.lookup_line_range($span))
367 macro_rules! skip_out_of_file_lines_range {
368 ($self:ident, $span:expr) => {
369 if out_of_file_lines_range!($self, $span) {
375 macro_rules! skip_out_of_file_lines_range_visitor {
376 ($self:ident, $span:expr) => {
377 if out_of_file_lines_range!($self, $span) {
378 $self.push_rewrite($span, None);
384 // Wraps String in an Option. Returns Some when the string adheres to the
385 // Rewrite constraints defined for the Rewrite trait and None otherwise.
386 pub(crate) fn wrap_str(s: String, max_width: usize, shape: Shape) -> Option<String> {
387 if is_valid_str(&filter_normal_code(&s), max_width, shape) {
394 fn is_valid_str(snippet: &str, max_width: usize, shape: Shape) -> bool {
395 if !snippet.is_empty() {
396 // First line must fits with `shape.width`.
397 if first_line_width(snippet) > shape.width {
400 // If the snippet does not include newline, we are done.
401 if is_single_line(snippet) {
404 // The other lines must fit within the maximum width.
408 .any(|line| unicode_str_width(line) > max_width)
412 // A special check for the last line, since the caller may
413 // place trailing characters on this line.
414 if last_line_width(snippet) > shape.used_width() + shape.width {
422 pub(crate) fn colon_spaces(config: &Config) -> &'static str {
423 let before = config.space_before_colon();
424 let after = config.space_after_colon();
425 match (before, after) {
426 (true, true) => " : ",
427 (true, false) => " :",
428 (false, true) => ": ",
429 (false, false) => ":",
434 pub(crate) fn left_most_sub_expr(e: &ast::Expr) -> &ast::Expr {
436 ast::ExprKind::Call(ref e, _)
437 | ast::ExprKind::Binary(_, ref e, _)
438 | ast::ExprKind::Cast(ref e, _)
439 | ast::ExprKind::Type(ref e, _)
440 | ast::ExprKind::Assign(ref e, _, _)
441 | ast::ExprKind::AssignOp(_, ref e, _)
442 | ast::ExprKind::Field(ref e, _)
443 | ast::ExprKind::Index(ref e, _)
444 | ast::ExprKind::Range(Some(ref e), _, _)
445 | ast::ExprKind::Try(ref e) => left_most_sub_expr(e),
451 pub(crate) fn starts_with_newline(s: &str) -> bool {
452 s.starts_with('\n') || s.starts_with("\r\n")
456 pub(crate) fn first_line_ends_with(s: &str, c: char) -> bool {
457 s.lines().next().map_or(false, |l| l.ends_with(c))
460 // States whether an expression's last line exclusively consists of closing
461 // parens, braces, and brackets in its idiomatic formatting.
462 pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr: &str) -> bool {
464 ast::ExprKind::MacCall(..)
465 | ast::ExprKind::Call(..)
466 | ast::ExprKind::MethodCall(..)
467 | ast::ExprKind::Array(..)
468 | ast::ExprKind::Struct(..)
469 | ast::ExprKind::While(..)
470 | ast::ExprKind::If(..)
471 | ast::ExprKind::Block(..)
472 | ast::ExprKind::ConstBlock(..)
473 | ast::ExprKind::Async(..)
474 | ast::ExprKind::Loop(..)
475 | ast::ExprKind::ForLoop(..)
476 | ast::ExprKind::TryBlock(..)
477 | ast::ExprKind::Match(..) => repr.contains('\n'),
478 ast::ExprKind::Paren(ref expr)
479 | ast::ExprKind::Binary(_, _, ref expr)
480 | ast::ExprKind::Index(_, ref expr)
481 | ast::ExprKind::Unary(_, ref expr)
482 | ast::ExprKind::Closure(_, _, _, _, ref expr, _)
483 | ast::ExprKind::Try(ref expr)
484 | ast::ExprKind::Yield(Some(ref expr)) => is_block_expr(context, expr, repr),
485 // This can only be a string lit
486 ast::ExprKind::Lit(_) => {
487 repr.contains('\n') && trimmed_last_line_width(repr) <= context.config.tab_spaces()
489 ast::ExprKind::AddrOf(..)
490 | ast::ExprKind::Assign(..)
491 | ast::ExprKind::AssignOp(..)
492 | ast::ExprKind::Await(..)
493 | ast::ExprKind::Box(..)
494 | ast::ExprKind::Break(..)
495 | ast::ExprKind::Cast(..)
496 | ast::ExprKind::Continue(..)
498 | ast::ExprKind::Field(..)
499 | ast::ExprKind::InlineAsm(..)
500 | ast::ExprKind::Let(..)
501 | ast::ExprKind::Path(..)
502 | ast::ExprKind::Range(..)
503 | ast::ExprKind::Repeat(..)
504 | ast::ExprKind::Ret(..)
505 | ast::ExprKind::Yeet(..)
506 | ast::ExprKind::Tup(..)
507 | ast::ExprKind::Type(..)
508 | ast::ExprKind::Yield(None)
509 | ast::ExprKind::Underscore => false,
513 /// Removes trailing spaces from the specified snippet. We do not remove spaces
514 /// inside strings or comments.
515 pub(crate) fn remove_trailing_white_spaces(text: &str) -> String {
516 let mut buffer = String::with_capacity(text.len());
517 let mut space_buffer = String::with_capacity(128);
518 for (char_kind, c) in CharClasses::new(text.chars()) {
521 if char_kind == FullCodeCharKind::InString {
522 buffer.push_str(&space_buffer);
524 space_buffer.clear();
527 _ if c.is_whitespace() => {
528 space_buffer.push(c);
531 if !space_buffer.is_empty() {
532 buffer.push_str(&space_buffer);
533 space_buffer.clear();
542 /// Indent each line according to the specified `indent`.
545 /// ```rust,compile_fail
559 /// ```rust,compile_fail
570 pub(crate) fn trim_left_preserve_layout(
574 ) -> Option<String> {
575 let mut lines = LineClasses::new(orig);
576 let first_line = lines.next().map(|(_, s)| s.trim_end().to_owned())?;
577 let mut trimmed_lines = Vec::with_capacity(16);
579 let mut veto_trim = false;
580 let min_prefix_space_width = lines
581 .filter_map(|(kind, line)| {
582 let mut trimmed = true;
583 let prefix_space_width = if is_empty_line(&line) {
586 Some(get_prefix_space_width(config, &line))
589 // just InString{Commented} in order to allow the start of a string to be indented
590 let new_veto_trim_value = (kind == FullCodeCharKind::InString
591 || (config.version() == Version::Two
592 && kind == FullCodeCharKind::InStringCommented))
593 && !line.ends_with('\\');
594 let line = if veto_trim || new_veto_trim_value {
595 veto_trim = new_veto_trim_value;
599 line.trim().to_owned()
601 trimmed_lines.push((trimmed, line, prefix_space_width));
603 // Because there is a veto against trimming and indenting lines within a string,
604 // such lines should not be taken into account when computing the minimum.
606 FullCodeCharKind::InStringCommented | FullCodeCharKind::EndStringCommented
607 if config.version() == Version::Two =>
611 FullCodeCharKind::InString | FullCodeCharKind::EndString => None,
612 _ => prefix_space_width,
623 |&(trimmed, ref line, prefix_space_width)| match prefix_space_width {
624 _ if !trimmed => line.to_owned(),
625 Some(original_indent_width) => {
626 let new_indent_width = indent.width()
627 + original_indent_width.saturating_sub(min_prefix_space_width);
628 let new_indent = Indent::from_width(config, new_indent_width);
629 format!("{}{}", new_indent.to_string(config), line)
631 None => String::new(),
639 /// Based on the given line, determine if the next line can be indented or not.
640 /// This allows to preserve the indentation of multi-line literals when
641 /// re-inserted a code block that has been formatted separately from the rest
642 /// of the code, such as code in macro defs or code blocks doc comments.
643 pub(crate) fn indent_next_line(kind: FullCodeCharKind, line: &str, config: &Config) -> bool {
644 if kind.is_string() {
645 // If the string ends with '\', the string has been wrapped over
646 // multiple lines. If `format_strings = true`, then the indentation of
647 // strings wrapped over multiple lines will have been adjusted while
648 // formatting the code block, therefore the string's indentation needs
649 // to be adjusted for the code surrounding the code block.
650 config.format_strings() && line.ends_with('\\')
651 } else if config.version() == Version::Two {
652 !kind.is_commented_string()
658 pub(crate) fn is_empty_line(s: &str) -> bool {
659 s.is_empty() || s.chars().all(char::is_whitespace)
662 fn get_prefix_space_width(config: &Config, s: &str) -> usize {
667 '\t' => width += config.tab_spaces(),
674 pub(crate) trait NodeIdExt {
678 impl NodeIdExt for NodeId {
679 fn root() -> NodeId {
680 NodeId::placeholder_from_expn_id(LocalExpnId::ROOT)
684 pub(crate) fn unicode_str_width(s: &str) -> usize {
693 fn test_remove_trailing_white_spaces() {
694 let s = " r#\"\n test\n \"#";
695 assert_eq!(remove_trailing_white_spaces(s), s);
699 fn test_trim_left_preserve_layout() {
700 let s = "aaa\n\tbbb\n ccc";
701 let config = Config::default();
702 let indent = Indent::new(4, 0);
704 trim_left_preserve_layout(s, indent, &config),
705 Some("aaa\n bbb\n ccc".to_string())