src/filemap.rs

   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.
   4 //
   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.
  10
  11 // TODO: add tests
  12
  13 use std::fs::{self, File};
  14 use std::io::{self, BufWriter, Read, Write};
  15 use std::path::Path;
  16
  17 use checkstyle::{output_checkstyle_file, output_footer, output_header};
  18 use config::{Config, NewlineStyle, WriteMode};
  19 use rustfmt_diff::{make_diff, print_diff, Mismatch};
  20 use syntax::codemap::FileName;
  21
  22 // A map of the files of a crate, with their new content
  23 pub type FileMap = Vec<FileRecord>;
  24
  25 pub type FileRecord = (FileName, String);
  26
  27 // Append a newline to the end of each file.
  28 pub fn append_newline(s: &mut String) {
  29     s.push_str("\n");
  30 }
  31
  32 pub fn write_all_files<T>(
  33     file_map: &[FileRecord],
  34     out: &mut T,
  35     config: &Config,
  36 ) -> Result<(), io::Error>
  37 where
  38     T: Write,
  39 {
  40     output_header(out, config.write_mode()).ok();
  41     for &(ref filename, ref text) in file_map {
  42         write_file(text, filename, out, config)?;
  43     }
  44     output_footer(out, config.write_mode()).ok();
  45
  46     Ok(())
  47 }
  48
  49 // Prints all newlines either as `\n` or as `\r\n`.
  50 pub fn write_system_newlines<T>(writer: T, text: &str, config: &Config) -> Result<(), io::Error>
  51 where
  52     T: Write,
  53 {
  54     // Buffer output, since we're writing a since char at a time.
  55     let mut writer = BufWriter::new(writer);
  56
  57     let style = if config.newline_style() == NewlineStyle::Native {
  58         if cfg!(windows) {
  59             NewlineStyle::Windows
  60         } else {
  61             NewlineStyle::Unix
  62         }
  63     } else {
  64         config.newline_style()
  65     };
  66
  67     match style {
  68         NewlineStyle::Unix => write!(writer, "{}", text),
  69         NewlineStyle::Windows => {
  70             for c in text.chars() {
  71                 match c {
  72                     '\n' => write!(writer, "\r\n")?,
  73                     '\r' => continue,
  74                     c => write!(writer, "{}", c)?,
  75                 }
  76             }
  77             Ok(())
  78         }
  79         NewlineStyle::Native => unreachable!(),
  80     }
  81 }
  82
  83 pub fn write_file<T>(
  84     text: &str,
  85     filename: &FileName,
  86     out: &mut T,
  87     config: &Config,
  88 ) -> Result<bool, io::Error>
  89 where
  90     T: Write,
  91 {
  92     fn source_and_formatted_text(
  93         text: &str,
  94         filename: &Path,
  95         config: &Config,
  96     ) -> Result<(String, String), io::Error> {
  97         let mut f = File::open(filename)?;
  98         let mut ori_text = String::new();
  99         f.read_to_string(&mut ori_text)?;
 100         let mut v = Vec::new();
 101         write_system_newlines(&mut v, text, config)?;
 102         let fmt_text = String::from_utf8(v).unwrap();
 103         Ok((ori_text, fmt_text))
 104     }
 105
 106     fn create_diff(
 107         filename: &Path,
 108         text: &str,
 109         config: &Config,
 110     ) -> Result<Vec<Mismatch>, io::Error> {
 111         let (ori, fmt) = source_and_formatted_text(text, filename, config)?;
 112         Ok(make_diff(&ori, &fmt, 3))
 113     }
 114
 115     let filename_to_path = || match *filename {
 116         FileName::Real(ref path) => path,
 117         _ => panic!("cannot format `{}` with WriteMode::Replace", filename),
 118     };
 119
 120     match config.write_mode() {
 121         WriteMode::Replace => {
 122             let filename = filename_to_path();
 123             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 124                 if fmt != ori {
 125                     // Do a little dance to make writing safer - write to a temp file
 126                     // rename the original to a .bk, then rename the temp file to the
 127                     // original.
 128                     let tmp_name = filename.with_extension("tmp");
 129                     let bk_name = filename.with_extension("bk");
 130                     {
 131                         // Write text to temp file
 132                         let tmp_file = File::create(&tmp_name)?;
 133                         write_system_newlines(tmp_file, text, config)?;
 134                     }
 135
 136                     fs::rename(filename, bk_name)?;
 137                     fs::rename(tmp_name, filename)?;
 138                 }
 139             }
 140         }
 141         WriteMode::Overwrite => {
 142             // Write text directly over original file if there is a diff.
 143             let filename = filename_to_path();
 144             let (source, formatted) = source_and_formatted_text(text, filename, config)?;
 145             if source != formatted {
 146                 let file = File::create(filename)?;
 147                 write_system_newlines(file, text, config)?;
 148             }
 149         }
 150         WriteMode::Plain => {
 151             write_system_newlines(out, text, config)?;
 152         }
 153         WriteMode::Display | WriteMode::Coverage => {
 154             println!("{}:\n", filename);
 155             write_system_newlines(out, text, config)?;
 156         }
 157         WriteMode::Diff => {
 158             let filename = filename_to_path();
 159             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 160                 let mismatch = make_diff(&ori, &fmt, 3);
 161                 let has_diff = !mismatch.is_empty();
 162                 print_diff(
 163                     mismatch,
 164                     |line_num| format!("Diff in {} at line {}:", filename.display(), line_num),
 165                     config.color(),
 166                 );
 167                 return Ok(has_diff);
 168             }
 169         }
 170         WriteMode::Checkstyle => {
 171             let filename = filename_to_path();
 172             let diff = create_diff(filename, text, config)?;
 173             output_checkstyle_file(out, filename, diff)?;
 174         }
 175     }
 176
 177     // when we are not in diff mode, don't indicate differing files
 178     Ok(false)
 179 }