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.
12 use std::cmp::Ordering;
15 use syntax::ast::{self, Attribute, MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind,
17 use syntax::codemap::{BytePos, Span, NO_EXPANSION};
20 use rewrite::{Rewrite, RewriteContext};
22 // When we get scoped annotations, we should have rustfmt::skip.
23 const SKIP_ANNOTATION: &'static str = "rustfmt_skip";
25 // Computes the length of a string's last line, minus offset.
26 pub fn extra_offset(text: &str, shape: Shape) -> usize {
27 match text.rfind('\n') {
28 // 1 for newline character
29 Some(idx) => text.len()
30 .checked_sub(idx + 1 + shape.used_width())
36 // Uses Cow to avoid allocating in the common cases.
37 pub fn format_visibility(vis: &Visibility) -> Cow<'static, str> {
39 Visibility::Public => Cow::from("pub "),
40 Visibility::Inherited => Cow::from(""),
41 Visibility::Crate(_) => Cow::from("pub(crate) "),
42 Visibility::Restricted { ref path, .. } => {
43 let Path { ref segments, .. } = **path;
44 let mut segments_iter = segments.iter().map(|seg| seg.identifier.name.to_string());
48 .expect("Non-global path in pub(restricted)?");
50 let is_keyword = |s: &str| s == "self" || s == "super";
51 let path = segments_iter.collect::<Vec<_>>().join("::");
52 let in_str = if is_keyword(&path) { "" } else { "in " };
54 Cow::from(format!("pub({}{}) ", in_str, path))
60 pub fn format_constness(constness: ast::Constness) -> &'static str {
62 ast::Constness::Const => "const ",
63 ast::Constness::NotConst => "",
68 pub fn format_defaultness(defaultness: ast::Defaultness) -> &'static str {
70 ast::Defaultness::Default => "default ",
71 ast::Defaultness::Final => "",
76 pub fn format_unsafety(unsafety: ast::Unsafety) -> &'static str {
78 ast::Unsafety::Unsafe => "unsafe ",
79 ast::Unsafety::Normal => "",
84 pub fn format_mutability(mutability: ast::Mutability) -> &'static str {
86 ast::Mutability::Mutable => "mut ",
87 ast::Mutability::Immutable => "",
92 pub fn format_abi(abi: abi::Abi, explicit_abi: bool) -> String {
93 if abi == abi::Abi::C && !explicit_abi {
96 format!("extern {} ", abi)
101 pub fn filter_attributes(attrs: &[ast::Attribute], style: ast::AttrStyle) -> Vec<ast::Attribute> {
104 .filter(|a| a.style == style)
110 pub fn inner_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
111 filter_attributes(attrs, ast::AttrStyle::Inner)
115 pub fn outer_attributes(attrs: &[ast::Attribute]) -> Vec<ast::Attribute> {
116 filter_attributes(attrs, ast::AttrStyle::Outer)
119 // The width of the first line in s.
121 pub fn first_line_width(s: &str) -> usize {
128 // The width of the last line in s.
130 pub fn last_line_width(s: &str) -> usize {
131 match s.rfind('\n') {
132 Some(n) => s.len() - n - 1,
137 // The total used width of the last line.
139 pub fn last_line_used_width(s: &str, offset: usize) -> usize {
140 if s.contains('\n') {
148 pub fn trimmed_last_line_width(s: &str) -> usize {
149 match s.rfind('\n') {
150 Some(n) => s[(n + 1)..].trim().len(),
151 None => s.trim().len(),
156 pub fn last_line_extendable(s: &str) -> bool {
157 s.lines().last().map_or(false, |s| {
158 s.ends_with("\"#") ||
161 .all(|c| c == ')' || c == ']' || c == '}' || c == '?')
166 fn is_skip(meta_item: &MetaItem) -> bool {
167 match meta_item.node {
168 MetaItemKind::Word => meta_item.name == SKIP_ANNOTATION,
169 MetaItemKind::List(ref l) => {
170 meta_item.name == "cfg_attr" && l.len() == 2 && is_skip_nested(&l[1])
177 fn is_skip_nested(meta_item: &NestedMetaItem) -> bool {
178 match meta_item.node {
179 NestedMetaItemKind::MetaItem(ref mi) => is_skip(mi),
180 NestedMetaItemKind::Literal(_) => false,
185 pub fn contains_skip(attrs: &[Attribute]) -> bool {
188 .any(|a| a.meta().map_or(false, |a| is_skip(&a)))
191 // Find the end of a TyParam
193 pub fn end_typaram(typaram: &ast::TyParam) -> BytePos {
197 .map_or(typaram.span, |bound| match *bound {
198 ast::RegionTyParamBound(ref lt) => lt.span,
199 ast::TraitTyParamBound(ref prt, _) => prt.span,
205 pub fn semicolon_for_expr(context: &RewriteContext, expr: &ast::Expr) -> bool {
207 ast::ExprKind::Ret(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Break(..) => {
208 context.config.trailing_semicolon()
215 pub fn semicolon_for_stmt(context: &RewriteContext, stmt: &ast::Stmt) -> bool {
217 ast::StmtKind::Semi(ref expr) => match expr.node {
218 ast::ExprKind::While(..) |
219 ast::ExprKind::WhileLet(..) |
220 ast::ExprKind::Loop(..) |
221 ast::ExprKind::ForLoop(..) => false,
222 ast::ExprKind::Break(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Ret(..) => {
223 context.config.trailing_semicolon()
227 ast::StmtKind::Expr(..) => false,
233 pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
235 ast::StmtKind::Expr(ref expr) => Some(expr),
241 pub fn trim_newlines(input: &str) -> &str {
242 match input.find(|c| c != '\n' && c != '\r') {
244 let end = input.rfind(|c| c != '\n' && c != '\r').unwrap_or(0) + 1;
251 // Macro for deriving implementations of Serialize/Deserialize for enums
253 macro_rules! impl_enum_serialize_and_deserialize {
254 ( $e:ident, $( $x:ident ),* ) => {
255 impl ::serde::ser::Serialize for $e {
256 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
257 where S: ::serde::ser::Serializer
259 use serde::ser::Error;
261 // We don't know whether the user of the macro has given us all options.
262 #[allow(unreachable_patterns)]
265 $e::$x => serializer.serialize_str(stringify!($x)),
268 Err(S::Error::custom(format!("Cannot serialize {:?}", self)))
274 impl<'de> ::serde::de::Deserialize<'de> for $e {
275 fn deserialize<D>(d: D) -> Result<Self, D::Error>
276 where D: ::serde::Deserializer<'de> {
277 use std::ascii::AsciiExt;
278 use serde::de::{Error, Visitor};
279 use std::marker::PhantomData;
281 struct StringOnly<T>(PhantomData<T>);
282 impl<'de, T> Visitor<'de> for StringOnly<T>
283 where T: ::serde::Deserializer<'de> {
285 fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
286 formatter.write_str("string")
288 fn visit_str<E>(self, value: &str) -> Result<String, E> {
289 Ok(String::from(value))
292 let s = d.deserialize_string(StringOnly::<D>(PhantomData))?;
294 if stringify!($x).eq_ignore_ascii_case(&s) {
298 static ALLOWED: &'static[&str] = &[$(stringify!($x),)*];
299 Err(D::Error::unknown_variant(&s, ALLOWED))
303 impl ::std::str::FromStr for $e {
304 type Err = &'static str;
306 fn from_str(s: &str) -> Result<Self, Self::Err> {
307 use std::ascii::AsciiExt;
309 if stringify!($x).eq_ignore_ascii_case(s) {
317 impl ::config::ConfigType for $e {
318 fn doc_hint() -> String {
319 let mut variants = Vec::new();
321 variants.push(stringify!($x));
323 format!("[{}]", variants.join("|"))
329 // Same as try!, but for Option
331 macro_rules! try_opt {
332 ($expr:expr) => (match $expr {
334 None => { return None; }
340 match writeln!(&mut ::std::io::stderr(), $($arg)* ) {
342 Err(x) => panic!("Unable to write to stderr: {}", x),
347 // For format_missing and last_pos, need to use the source callsite (if applicable).
348 // Required as generated code spans aren't guaranteed to follow on from the last span.
349 macro_rules! source {
350 ($this:ident, $sp: expr) => {
351 $sp.source_callsite()
355 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
363 // Return true if the given span does not intersect with file lines.
364 macro_rules! out_of_file_lines_range {
365 ($self:ident, $span:expr) => {
368 .intersects(&$self.codemap.lookup_line_range($span))
372 macro_rules! skip_out_of_file_lines_range {
373 ($self:ident, $span:expr) => {
374 if out_of_file_lines_range!($self, $span) {
380 macro_rules! skip_out_of_file_lines_range_visitor {
381 ($self:ident, $span:expr) => {
382 if out_of_file_lines_range!($self, $span) {
383 $self.push_rewrite($span, None);
389 // Wraps string-like values in an Option. Returns Some when the string adheres
390 // to the Rewrite constraints defined for the Rewrite trait and else otherwise.
391 pub fn wrap_str<S: AsRef<str>>(s: S, max_width: usize, shape: Shape) -> Option<S> {
393 let snippet = s.as_ref();
395 if !snippet.is_empty() {
396 if !snippet.contains('\n') && snippet.len() > shape.width {
399 let mut lines = snippet.lines();
401 if lines.next().unwrap().len() > shape.width {
405 // The other lines must fit within the maximum width.
406 if lines.any(|line| line.len() > max_width) {
410 // `width` is the maximum length of the last line, excluding
412 // A special check for the last line, since the caller may
413 // place trailing characters on this line.
414 if snippet.lines().rev().next().unwrap().len() > shape.used_width() + shape.width {
424 impl Rewrite for String {
425 fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
426 wrap_str(self, context.config.max_width(), shape).map(ToOwned::to_owned)
430 // Binary search in integer range. Returns the first Ok value returned by the
432 // The callback takes an integer and returns either an Ok, or an Err indicating
433 // whether the `guess' was too high (Ordering::Less), or too low.
434 // This function is guaranteed to try to the hi value first.
435 pub fn binary_search<C, T>(mut lo: usize, mut hi: usize, callback: C) -> Option<T>
437 C: Fn(usize) -> Result<T, Ordering>,
442 match callback(middle) {
443 Ok(val) => return Some(val),
444 Err(Ordering::Less) => {
451 middle = (hi + lo) / 2;
458 pub fn colon_spaces(before: bool, after: bool) -> &'static str {
459 match (before, after) {
460 (true, true) => " : ",
461 (true, false) => " :",
462 (false, true) => ": ",
463 (false, false) => ":",
468 pub fn paren_overhead(context: &RewriteContext) -> usize {
469 if context.config.spaces_within_parens() {
477 fn bin_search_test() {
478 let closure = |i| match i {
480 j if j > 4 => Err(Ordering::Less),
481 j if j < 4 => Err(Ordering::Greater),
485 assert_eq!(Some(()), binary_search(1, 10, &closure));
486 assert_eq!(None, binary_search(1, 3, &closure));
487 assert_eq!(Some(()), binary_search(0, 44, &closure));
488 assert_eq!(Some(()), binary_search(4, 125, &closure));
489 assert_eq!(None, binary_search(6, 100, &closure));
492 pub fn left_most_sub_expr(e: &ast::Expr) -> &ast::Expr {
494 ast::ExprKind::InPlace(ref e, _) |
495 ast::ExprKind::Call(ref e, _) |
496 ast::ExprKind::Binary(_, ref e, _) |
497 ast::ExprKind::Cast(ref e, _) |
498 ast::ExprKind::Type(ref e, _) |
499 ast::ExprKind::Assign(ref e, _) |
500 ast::ExprKind::AssignOp(_, ref e, _) |
501 ast::ExprKind::Field(ref e, _) |
502 ast::ExprKind::TupField(ref e, _) |
503 ast::ExprKind::Index(ref e, _) |
504 ast::ExprKind::Range(Some(ref e), _, _) |
505 ast::ExprKind::Try(ref e) => left_most_sub_expr(e),