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.
13 use syntax::codemap::{BytePos, Pos, Span};
15 use comment::{rewrite_comment, CodeCharKind, CommentCodeSlices};
16 use config::WriteMode;
17 use shape::{Indent, Shape};
19 use visitor::FmtVisitor;
21 impl<'a> FmtVisitor<'a> {
22 fn output_at_start(&self) -> bool {
26 // TODO these format_missing methods are ugly. Refactor and add unit tests
27 // for the central whitespace stripping loop.
28 pub fn format_missing(&mut self, end: BytePos) {
29 self.format_missing_inner(end, |this, last_snippet, _| {
30 this.buffer.push_str(last_snippet)
34 pub fn format_missing_with_indent(&mut self, end: BytePos) {
35 let config = self.config;
36 self.format_missing_inner(end, |this, last_snippet, snippet| {
37 this.buffer.push_str(last_snippet.trim_right());
38 if last_snippet == snippet && !this.output_at_start() {
39 // No new lines in the snippet.
40 this.buffer.push_str("\n");
42 let indent = this.block_indent.to_string(config);
43 this.buffer.push_str(&indent);
47 pub fn format_missing_no_indent(&mut self, end: BytePos) {
48 self.format_missing_inner(end, |this, last_snippet, _| {
49 this.buffer.push_str(last_snippet.trim_right());
53 fn format_missing_inner<F: Fn(&mut FmtVisitor, &str, &str)>(
56 process_last_snippet: F,
58 let start = self.last_pos;
61 // Do nothing if this is the beginning of the file.
62 if !self.output_at_start() {
63 process_last_snippet(self, "", "");
70 "Request to format inverted span: {:?} to {:?}",
71 self.codemap.lookup_char_pos(start),
72 self.codemap.lookup_char_pos(end)
76 let span = mk_sp(start, end);
78 self.write_snippet(span, &process_last_snippet);
81 fn write_snippet<F>(&mut self, span: Span, process_last_snippet: F)
83 F: Fn(&mut FmtVisitor, &str, &str),
85 // Get a snippet from the file start to the span's hi without allocating.
86 // We need it to determine what precedes the current comment. If the comment
87 // follows code on the same line, we won't touch it.
88 let big_span_lo = self.codemap.lookup_char_pos(span.lo()).file.start_pos;
89 let local_begin = self.codemap.lookup_byte_offset(big_span_lo);
90 let local_end = self.codemap.lookup_byte_offset(span.hi());
91 let start_index = local_begin.pos.to_usize();
92 let end_index = local_end.pos.to_usize();
93 let big_snippet = &local_begin.fm.src.as_ref().unwrap()[start_index..end_index];
95 let big_diff = (span.lo() - big_span_lo).to_usize();
96 let snippet = self.snippet(span);
98 debug!("write_snippet `{}`", snippet);
100 self.write_snippet_inner(big_snippet, big_diff, &snippet, span, process_last_snippet);
103 fn write_snippet_inner<F>(
109 process_last_snippet: F,
111 F: Fn(&mut FmtVisitor, &str, &str),
113 // Trim whitespace from the right hand side of each line.
114 // Annoyingly, the library functions for splitting by lines etc. are not
115 // quite right, so we must do it ourselves.
116 let mut line_start = 0;
117 let mut last_wspace = None;
118 let mut rewrite_next_comment = true;
120 let char_pos = self.codemap.lookup_char_pos(span.lo());
121 let file_name = &char_pos.file.name;
122 let mut cur_line = char_pos.line;
124 fn replace_chars<'a>(string: &'a str) -> Cow<'a, str> {
125 if string.contains(char::is_whitespace) {
129 .map(|ch| if ch.is_whitespace() { ch } else { 'X' })
130 .collect::<String>(),
137 let snippet = &*match self.config.write_mode() {
138 WriteMode::Coverage => replace_chars(old_snippet),
139 _ => Cow::from(old_snippet),
142 for (kind, offset, subslice) in CommentCodeSlices::new(snippet) {
143 debug!("{:?}: {:?}", kind, subslice);
145 if let CodeCharKind::Comment = kind {
146 let last_char = big_snippet[..(offset + big_diff)]
149 .skip_while(|rev_c| [' ', '\t'].contains(rev_c))
152 let fix_indent = last_char.map_or(true, |rev_c| ['{', '\n'].contains(&rev_c));
154 let subslice_num_lines = subslice.chars().filter(|c| *c == '\n').count();
156 if rewrite_next_comment
157 && !self.config.file_lines().intersects_range(
160 cur_line + subslice_num_lines,
162 rewrite_next_comment = false;
165 if rewrite_next_comment {
167 if let Some('{') = last_char {
168 self.buffer.push_str("\n");
171 .push_str(&self.block_indent.to_string(self.config));
173 self.buffer.push_str(" ");
176 let comment_width = ::std::cmp::min(
177 self.config.comment_width(),
178 self.config.max_width() - self.block_indent.width(),
180 let comment_indent = Indent::from_width(self.config, self.buffer.cur_offset());
182 self.buffer.push_str(&rewrite_comment(
185 Shape::legacy(comment_width, comment_indent),
190 line_start = offset + subslice.len();
192 if let Some('/') = subslice.chars().nth(1) {
193 // check that there are no contained block comments
196 .map(|s| s.trim_left())
197 .any(|s| s.len() >= 2 && &s[0..2] == "/*")
199 // Add a newline after line comments
200 self.buffer.push_str("\n");
202 } else if line_start <= snippet.len() {
203 // For other comments add a newline if there isn't one at the end already
204 match snippet[line_start..].chars().next() {
205 Some('\n') | Some('\r') => (),
206 _ => self.buffer.push_str("\n"),
210 cur_line += subslice_num_lines;
213 rewrite_next_comment = false;
217 for (mut i, c) in subslice.char_indices() {
221 if !self.config.file_lines().contains_line(file_name, cur_line) {
225 if let Some(lw) = last_wspace {
226 self.buffer.push_str(&snippet[line_start..lw]);
227 self.buffer.push_str("\n");
229 self.buffer.push_str(&snippet[line_start..i + 1]);
235 rewrite_next_comment = rewrite_next_comment || kind == CodeCharKind::Normal;
236 } else if c.is_whitespace() {
237 if last_wspace.is_none() {
238 last_wspace = Some(i);
241 if last_wspace.is_some() {
245 rewrite_next_comment = rewrite_next_comment || kind == CodeCharKind::Normal;
248 rewrite_next_comment = rewrite_next_comment || kind == CodeCharKind::Normal;
253 let remaining = snippet[line_start..subslice.len() + offset].trim();
254 if !remaining.is_empty() {
255 self.buffer.push_str(remaining);
256 line_start = subslice.len() + offset;
257 rewrite_next_comment = rewrite_next_comment || kind == CodeCharKind::Normal;
261 process_last_snippet(self, &snippet[line_start..], snippet);