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_defaultness(defaultness: ast::Defaultness) -> &'static str {
62 ast::Defaultness::Default => "default ",
63 ast::Defaultness::Final => "",
68 pub fn format_unsafety(unsafety: ast::Unsafety) -> &'static str {
70 ast::Unsafety::Unsafe => "unsafe ",
71 ast::Unsafety::Normal => "",
76 pub fn format_mutability(mutability: ast::Mutability) -> &'static str {
78 ast::Mutability::Mutable => "mut ",
79 ast::Mutability::Immutable => "",
84 pub fn format_abi(abi: abi::Abi, explicit_abi: bool) -> String {
85 if abi == abi::Abi::C && !explicit_abi {
88 format!("extern {} ", abi)
92 // The width of the first line in s.
94 pub fn first_line_width(s: &str) -> usize {
101 // The width of the last line in s.
103 pub fn last_line_width(s: &str) -> usize {
104 match s.rfind('\n') {
105 Some(n) => s.len() - n - 1,
111 pub fn trimmed_last_line_width(s: &str) -> usize {
112 match s.rfind('\n') {
113 Some(n) => s[(n + 1)..].trim().len(),
114 None => s.trim().len(),
119 pub fn last_line_extendable(s: &str) -> bool {
120 s.lines().last().map_or(false, |s| {
121 s.ends_with("\"#") ||
124 .all(|c| c == ')' || c == ']' || c == '}' || c == '?')
129 fn is_skip(meta_item: &MetaItem) -> bool {
130 match meta_item.node {
131 MetaItemKind::Word => meta_item.name == SKIP_ANNOTATION,
132 MetaItemKind::List(ref l) => {
133 meta_item.name == "cfg_attr" && l.len() == 2 && is_skip_nested(&l[1])
140 fn is_skip_nested(meta_item: &NestedMetaItem) -> bool {
141 match meta_item.node {
142 NestedMetaItemKind::MetaItem(ref mi) => is_skip(mi),
143 NestedMetaItemKind::Literal(_) => false,
148 pub fn contains_skip(attrs: &[Attribute]) -> bool {
151 .any(|a| a.meta().map_or(false, |a| is_skip(&a)))
154 // Find the end of a TyParam
156 pub fn end_typaram(typaram: &ast::TyParam) -> BytePos {
160 .map_or(typaram.span, |bound| match *bound {
161 ast::RegionTyParamBound(ref lt) => lt.span,
162 ast::TraitTyParamBound(ref prt, _) => prt.span,
168 pub fn semicolon_for_expr(context: &RewriteContext, expr: &ast::Expr) -> bool {
170 ast::ExprKind::Ret(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Break(..) => {
171 context.config.trailing_semicolon()
178 pub fn semicolon_for_stmt(context: &RewriteContext, stmt: &ast::Stmt) -> bool {
180 ast::StmtKind::Semi(ref expr) => match expr.node {
181 ast::ExprKind::While(..) |
182 ast::ExprKind::WhileLet(..) |
183 ast::ExprKind::Loop(..) |
184 ast::ExprKind::ForLoop(..) => false,
185 ast::ExprKind::Break(..) | ast::ExprKind::Continue(..) | ast::ExprKind::Ret(..) => {
186 context.config.trailing_semicolon()
190 ast::StmtKind::Expr(..) => false,
196 pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
198 ast::StmtKind::Expr(ref expr) => Some(expr),
204 pub fn trim_newlines(input: &str) -> &str {
205 match input.find(|c| c != '\n' && c != '\r') {
207 let end = input.rfind(|c| c != '\n' && c != '\r').unwrap_or(0) + 1;
214 // Macro for deriving implementations of Serialize/Deserialize for enums
216 macro_rules! impl_enum_serialize_and_deserialize {
217 ( $e:ident, $( $x:ident ),* ) => {
218 impl ::serde::ser::Serialize for $e {
219 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
220 where S: ::serde::ser::Serializer
222 use serde::ser::Error;
224 // We don't know whether the user of the macro has given us all options.
225 #[allow(unreachable_patterns)]
228 $e::$x => serializer.serialize_str(stringify!($x)),
231 Err(S::Error::custom(format!("Cannot serialize {:?}", self)))
237 impl<'de> ::serde::de::Deserialize<'de> for $e {
238 fn deserialize<D>(d: D) -> Result<Self, D::Error>
239 where D: ::serde::Deserializer<'de> {
240 use std::ascii::AsciiExt;
241 use serde::de::{Error, Visitor};
242 use std::marker::PhantomData;
244 struct StringOnly<T>(PhantomData<T>);
245 impl<'de, T> Visitor<'de> for StringOnly<T>
246 where T: ::serde::Deserializer<'de> {
248 fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
249 formatter.write_str("string")
251 fn visit_str<E>(self, value: &str) -> Result<String, E> {
252 Ok(String::from(value))
255 let s = d.deserialize_string(StringOnly::<D>(PhantomData))?;
257 if stringify!($x).eq_ignore_ascii_case(&s) {
261 static ALLOWED: &'static[&str] = &[$(stringify!($x),)*];
262 Err(D::Error::unknown_variant(&s, ALLOWED))
266 impl ::std::str::FromStr for $e {
267 type Err = &'static str;
269 fn from_str(s: &str) -> Result<Self, Self::Err> {
270 use std::ascii::AsciiExt;
272 if stringify!($x).eq_ignore_ascii_case(s) {
280 impl ::config::ConfigType for $e {
281 fn doc_hint() -> String {
282 let mut variants = Vec::new();
284 variants.push(stringify!($x));
286 format!("[{}]", variants.join("|"))
292 // Same as try!, but for Option
294 macro_rules! try_opt {
295 ($expr:expr) => (match $expr {
297 None => { return None; }
303 match writeln!(&mut ::std::io::stderr(), $($arg)* ) {
305 Err(x) => panic!("Unable to write to stderr: {}", x),
310 // For format_missing and last_pos, need to use the source callsite (if applicable).
311 // Required as generated code spans aren't guaranteed to follow on from the last span.
312 macro_rules! source {
313 ($this:ident, $sp: expr) => {
314 $sp.source_callsite()
318 pub fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
326 // Return true if the given span does not intersect with file lines.
327 macro_rules! out_of_file_lines_range {
328 ($self:ident, $span:expr) => {
331 .intersects(&$self.codemap.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-like values in an Option. Returns Some when the string adheres
353 // to the Rewrite constraints defined for the Rewrite trait and else otherwise.
354 pub fn wrap_str<S: AsRef<str>>(s: S, max_width: usize, shape: Shape) -> Option<S> {
356 let snippet = s.as_ref();
358 if !snippet.is_empty() {
359 if !snippet.contains('\n') && snippet.len() > shape.width {
362 let mut lines = snippet.lines();
364 if lines.next().unwrap().len() > shape.width {
368 // The other lines must fit within the maximum width.
369 if lines.any(|line| line.len() > max_width) {
373 // `width` is the maximum length of the last line, excluding
375 // A special check for the last line, since the caller may
376 // place trailing characters on this line.
377 if snippet.lines().rev().next().unwrap().len() > shape.used_width() + shape.width {
387 impl Rewrite for String {
388 fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
389 wrap_str(self, context.config.max_width(), shape).map(ToOwned::to_owned)
393 // Binary search in integer range. Returns the first Ok value returned by the
395 // The callback takes an integer and returns either an Ok, or an Err indicating
396 // whether the `guess' was too high (Ordering::Less), or too low.
397 // This function is guaranteed to try to the hi value first.
398 pub fn binary_search<C, T>(mut lo: usize, mut hi: usize, callback: C) -> Option<T>
400 C: Fn(usize) -> Result<T, Ordering>,
405 match callback(middle) {
406 Ok(val) => return Some(val),
407 Err(Ordering::Less) => {
414 middle = (hi + lo) / 2;
421 pub fn colon_spaces(before: bool, after: bool) -> &'static str {
422 match (before, after) {
423 (true, true) => " : ",
424 (true, false) => " :",
425 (false, true) => ": ",
426 (false, false) => ":",
431 pub fn paren_overhead(context: &RewriteContext) -> usize {
432 if context.config.spaces_within_parens() {
440 fn bin_search_test() {
441 let closure = |i| match i {
443 j if j > 4 => Err(Ordering::Less),
444 j if j < 4 => Err(Ordering::Greater),
448 assert_eq!(Some(()), binary_search(1, 10, &closure));
449 assert_eq!(None, binary_search(1, 3, &closure));
450 assert_eq!(Some(()), binary_search(0, 44, &closure));
451 assert_eq!(Some(()), binary_search(4, 125, &closure));
452 assert_eq!(None, binary_search(6, 100, &closure));
455 pub fn left_most_sub_expr(e: &ast::Expr) -> &ast::Expr {
457 ast::ExprKind::InPlace(ref e, _) |
458 ast::ExprKind::Call(ref e, _) |
459 ast::ExprKind::Binary(_, ref e, _) |
460 ast::ExprKind::Cast(ref e, _) |
461 ast::ExprKind::Type(ref e, _) |
462 ast::ExprKind::Assign(ref e, _) |
463 ast::ExprKind::AssignOp(_, ref e, _) |
464 ast::ExprKind::Field(ref e, _) |
465 ast::ExprKind::TupField(ref e, _) |
466 ast::ExprKind::Index(ref e, _) |
467 ast::ExprKind::Range(Some(ref e), _, _) |
468 ast::ExprKind::Try(ref e) => left_most_sub_expr(e),