// filepatterns.rs // // Copyright 2019 Raphaël Gomès // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. //! Handling of Mercurial-specific patterns. use crate::{ utils::{ files::{canonical_path, get_bytes_from_path, get_path_from_bytes}, hg_path::{path_to_hg_path_buf, HgPathBuf, HgPathError}, SliceExt, }, FastHashMap, PatternError, }; use lazy_static::lazy_static; use regex::bytes::{NoExpand, Regex}; use std::ops::Deref; use std::path::{Path, PathBuf}; use std::vec::Vec; lazy_static! { static ref RE_ESCAPE: Vec> = { let mut v: Vec> = (0..=255).map(|byte| vec![byte]).collect(); let to_escape = b"()[]{}?*+-|^$\\.&~#\t\n\r\x0b\x0c"; for byte in to_escape { v[*byte as usize].insert(0, b'\\'); } v }; } /// These are matched in order const GLOB_REPLACEMENTS: &[(&[u8], &[u8])] = &[(b"*/", b"(?:.*/)?"), (b"*", b".*"), (b"", b"[^/]*")]; /// Appended to the regexp of globs const GLOB_SUFFIX: &[u8; 7] = b"(?:/|$)"; #[derive(Debug, Clone, PartialEq, Eq)] pub enum PatternSyntax { /// A regular expression Regexp, /// Glob that matches at the front of the path RootGlob, /// Glob that matches at any suffix of the path (still anchored at /// slashes) Glob, /// a path relative to repository root, which is matched recursively Path, /// a single exact path relative to repository root FilePath, /// A path relative to cwd RelPath, /// an unrooted glob (*.rs matches Rust files in all dirs) RelGlob, /// A regexp that needn't match the start of a name RelRegexp, /// A path relative to repository root, which is matched non-recursively /// (will not match subdirectories) RootFiles, /// A file of patterns to read and include Include, /// A file of patterns to match against files under the same directory SubInclude, /// SubInclude with the result of parsing the included file /// /// Note: there is no ExpandedInclude because that expansion can be done /// in place by replacing the Include pattern by the included patterns. /// SubInclude requires more handling. /// /// Note: `Box` is used to minimize size impact on other enum variants ExpandedSubInclude(Box), } /// Transforms a glob pattern into a regex fn glob_to_re(pat: &[u8]) -> Vec { let mut input = pat; let mut res: Vec = vec![]; let mut group_depth = 0; while let Some((c, rest)) = input.split_first() { input = rest; match c { b'*' => { for (source, repl) in GLOB_REPLACEMENTS { if let Some(rest) = input.drop_prefix(source) { input = rest; res.extend(*repl); break; } } } b'?' => res.extend(b"."), b'[' => { match input.iter().skip(1).position(|b| *b == b']') { None => res.extend(b"\\["), Some(end) => { // Account for the one we skipped let end = end + 1; res.extend(b"["); for (i, b) in input[..end].iter().enumerate() { if *b == b'!' && i == 0 { res.extend(b"^") } else if *b == b'^' && i == 0 { res.extend(b"\\^") } else if *b == b'\\' { res.extend(b"\\\\") } else { res.push(*b) } } res.extend(b"]"); input = &input[end + 1..]; } } } b'{' => { group_depth += 1; res.extend(b"(?:") } b'}' if group_depth > 0 => { group_depth -= 1; res.extend(b")"); } b',' if group_depth > 0 => res.extend(b"|"), b'\\' => { let c = { if let Some((c, rest)) = input.split_first() { input = rest; c } else { c } }; res.extend(&RE_ESCAPE[*c as usize]) } _ => res.extend(&RE_ESCAPE[*c as usize]), } } res } fn escape_pattern(pattern: &[u8]) -> Vec { pattern .iter() .flat_map(|c| RE_ESCAPE[*c as usize].clone()) .collect() } pub fn parse_pattern_syntax( kind: &[u8], ) -> Result { match kind { b"re:" => Ok(PatternSyntax::Regexp), b"path:" => Ok(PatternSyntax::Path), b"filepath:" => Ok(PatternSyntax::FilePath), b"relpath:" => Ok(PatternSyntax::RelPath), b"rootfilesin:" => Ok(PatternSyntax::RootFiles), b"relglob:" => Ok(PatternSyntax::RelGlob), b"relre:" => Ok(PatternSyntax::RelRegexp), b"glob:" => Ok(PatternSyntax::Glob), b"rootglob:" => Ok(PatternSyntax::RootGlob), b"include:" => Ok(PatternSyntax::Include), b"subinclude:" => Ok(PatternSyntax::SubInclude), _ => Err(PatternError::UnsupportedSyntax( String::from_utf8_lossy(kind).to_string(), )), } } lazy_static! { static ref FLAG_RE: Regex = Regex::new(r"^\(\?[aiLmsux]+\)").unwrap(); } /// Builds the regex that corresponds to the given pattern. /// If within a `syntax: regexp` context, returns the pattern, /// otherwise, returns the corresponding regex. fn _build_single_regex(entry: &IgnorePattern) -> Vec { let IgnorePattern { syntax, pattern, .. } = entry; if pattern.is_empty() { return vec![]; } match syntax { PatternSyntax::Regexp => pattern.to_owned(), PatternSyntax::RelRegexp => { // The `regex` crate accepts `**` while `re2` and Python's `re` // do not. Checking for `*` correctly triggers the same error all // engines. if pattern[0] == b'^' || pattern[0] == b'*' || pattern.starts_with(b".*") { return pattern.to_owned(); } match FLAG_RE.find(pattern) { Some(mat) => { let s = mat.start(); let e = mat.end(); [ &b"(?"[..], &pattern[s + 2..e - 1], &b":"[..], if pattern[e] == b'^' || pattern[e] == b'*' || pattern[e..].starts_with(b".*") { &b""[..] } else { &b".*"[..] }, &pattern[e..], &b")"[..], ] .concat() } None => [&b".*"[..], pattern].concat(), } } PatternSyntax::Path | PatternSyntax::RelPath => { if pattern == b"." { return vec![]; } [escape_pattern(pattern).as_slice(), b"(?:/|$)"].concat() } PatternSyntax::RootFiles => { let mut res = if pattern == b"." { vec![] } else { // Pattern is a directory name. [escape_pattern(pattern).as_slice(), b"/"].concat() }; // Anything after the pattern must be a non-directory. res.extend(b"[^/]+$"); res } PatternSyntax::RelGlob => { let glob_re = glob_to_re(pattern); if let Some(rest) = glob_re.drop_prefix(b"[^/]*") { [b".*", rest, GLOB_SUFFIX].concat() } else { [b"(?:.*/)?", glob_re.as_slice(), GLOB_SUFFIX].concat() } } PatternSyntax::Glob | PatternSyntax::RootGlob => { [glob_to_re(pattern).as_slice(), GLOB_SUFFIX].concat() } PatternSyntax::Include | PatternSyntax::SubInclude | PatternSyntax::ExpandedSubInclude(_) | PatternSyntax::FilePath => unreachable!(), } } const GLOB_SPECIAL_CHARACTERS: [u8; 7] = [b'*', b'?', b'[', b']', b'{', b'}', b'\\']; /// TODO support other platforms #[cfg(unix)] pub fn normalize_path_bytes(bytes: &[u8]) -> Vec { if bytes.is_empty() { return b".".to_vec(); } let sep = b'/'; let mut initial_slashes = bytes.iter().take_while(|b| **b == sep).count(); if initial_slashes > 2 { // POSIX allows one or two initial slashes, but treats three or more // as single slash. initial_slashes = 1; } let components = bytes .split(|b| *b == sep) .filter(|c| !(c.is_empty() || c == b".")) .fold(vec![], |mut acc, component| { if component != b".." || (initial_slashes == 0 && acc.is_empty()) || (!acc.is_empty() && acc[acc.len() - 1] == b"..") { acc.push(component) } else if !acc.is_empty() { acc.pop(); } acc }); let mut new_bytes = components.join(&sep); if initial_slashes > 0 { let mut buf: Vec<_> = (0..initial_slashes).map(|_| sep).collect(); buf.extend(new_bytes); new_bytes = buf; } if new_bytes.is_empty() { b".".to_vec() } else { new_bytes } } /// Wrapper function to `_build_single_regex` that short-circuits 'exact' globs /// that don't need to be transformed into a regex. pub fn build_single_regex( entry: &IgnorePattern, ) -> Result>, PatternError> { let IgnorePattern { pattern, syntax, .. } = entry; let pattern = match syntax { PatternSyntax::RootGlob | PatternSyntax::Path | PatternSyntax::RelGlob | PatternSyntax::RelPath | PatternSyntax::RootFiles => normalize_path_bytes(pattern), PatternSyntax::Include | PatternSyntax::SubInclude => { return Err(PatternError::NonRegexPattern(entry.clone())) } _ => pattern.to_owned(), }; let is_simple_rootglob = *syntax == PatternSyntax::RootGlob && !pattern.iter().any(|b| GLOB_SPECIAL_CHARACTERS.contains(b)); if is_simple_rootglob || syntax == &PatternSyntax::FilePath { Ok(None) } else { let mut entry = entry.clone(); entry.pattern = pattern; Ok(Some(_build_single_regex(&entry))) } } lazy_static! { static ref SYNTAXES: FastHashMap<&'static [u8], PatternSyntax> = { let mut m = FastHashMap::default(); m.insert(b"re:".as_ref(), PatternSyntax::Regexp); m.insert(b"regexp:".as_ref(), PatternSyntax::Regexp); m.insert(b"path:".as_ref(), PatternSyntax::Path); m.insert(b"filepath:".as_ref(), PatternSyntax::FilePath); m.insert(b"relpath:".as_ref(), PatternSyntax::RelPath); m.insert(b"rootfilesin:".as_ref(), PatternSyntax::RootFiles); m.insert(b"relglob:".as_ref(), PatternSyntax::RelGlob); m.insert(b"relre:".as_ref(), PatternSyntax::RelRegexp); m.insert(b"glob:".as_ref(), PatternSyntax::Glob); m.insert(b"rootglob:".as_ref(), PatternSyntax::RootGlob); m.insert(b"include:".as_ref(), PatternSyntax::Include); m.insert(b"subinclude:".as_ref(), PatternSyntax::SubInclude); m }; } #[derive(Debug)] pub enum PatternFileWarning { /// (file path, syntax bytes) InvalidSyntax(PathBuf, Vec), /// File path NoSuchFile(PathBuf), } pub fn parse_one_pattern( pattern: &[u8], source: &Path, default: PatternSyntax, ) -> IgnorePattern { let mut pattern_bytes: &[u8] = pattern; let mut syntax = default; for (s, val) in SYNTAXES.iter() { if let Some(rest) = pattern_bytes.drop_prefix(s) { syntax = val.clone(); pattern_bytes = rest; break; } } let pattern = pattern_bytes.to_vec(); IgnorePattern { syntax, pattern, source: source.to_owned(), } } pub fn parse_pattern_file_contents( lines: &[u8], file_path: &Path, default_syntax_override: Option, warn: bool, relativize: bool, ) -> Result<(Vec, Vec), PatternError> { let comment_regex = Regex::new(r"((?:^|[^\\])(?:\\\\)*)#.*").unwrap(); #[allow(clippy::trivial_regex)] let comment_escape_regex = Regex::new(r"\\#").unwrap(); let mut inputs: Vec = vec![]; let mut warnings: Vec = vec![]; let mut current_syntax = default_syntax_override.unwrap_or(PatternSyntax::RelRegexp); for mut line in lines.split(|c| *c == b'\n') { let line_buf; if line.contains(&b'#') { if let Some(cap) = comment_regex.captures(line) { line = &line[..cap.get(1).unwrap().end()] } line_buf = comment_escape_regex.replace_all(line, NoExpand(b"#")); line = &line_buf; } let line = line.trim_end(); if line.is_empty() { continue; } if let Some(syntax) = line.drop_prefix(b"syntax:") { let syntax = syntax.trim(); if let Some(parsed) = SYNTAXES.get([syntax, &b":"[..]].concat().as_slice()) { current_syntax = parsed.clone(); } else if warn { warnings.push(PatternFileWarning::InvalidSyntax( file_path.to_owned(), syntax.to_owned(), )); } } else { let pattern = parse_one_pattern( line, file_path, current_syntax.clone(), ); inputs.push(if relativize { pattern.to_relative() } else { pattern }) } } Ok((inputs, warnings)) } pub fn read_pattern_file( file_path: &Path, warn: bool, inspect_pattern_bytes: &mut impl FnMut(&Path, &[u8]), ) -> Result<(Vec, Vec), PatternError> { match std::fs::read(file_path) { Ok(contents) => { inspect_pattern_bytes(file_path, &contents); parse_pattern_file_contents(&contents, file_path, None, warn, true) } Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(( vec![], vec![PatternFileWarning::NoSuchFile(file_path.to_owned())], )), Err(e) => Err(e.into()), } } /// Represents an entry in an "ignore" file. #[derive(Debug, Eq, PartialEq, Clone)] pub struct IgnorePattern { pub syntax: PatternSyntax, pub pattern: Vec, pub source: PathBuf, } impl IgnorePattern { pub fn new(syntax: PatternSyntax, pattern: &[u8], source: &Path) -> Self { Self { syntax, pattern: pattern.to_owned(), source: source.to_owned(), } } pub fn to_relative(self) -> Self { let Self { syntax, pattern, source, } = self; Self { syntax: match syntax { PatternSyntax::Regexp => PatternSyntax::RelRegexp, PatternSyntax::Glob => PatternSyntax::RelGlob, x => x, }, pattern, source, } } } pub type PatternResult = Result; /// Wrapper for `read_pattern_file` that also recursively expands `include:` /// and `subinclude:` patterns. /// /// The former are expanded in place, while `PatternSyntax::ExpandedSubInclude` /// is used for the latter to form a tree of patterns. pub fn get_patterns_from_file( pattern_file: &Path, root_dir: &Path, inspect_pattern_bytes: &mut impl FnMut(&Path, &[u8]), ) -> PatternResult<(Vec, Vec)> { let (patterns, mut warnings) = read_pattern_file(pattern_file, true, inspect_pattern_bytes)?; let patterns = patterns .into_iter() .flat_map(|entry| -> PatternResult<_> { Ok(match &entry.syntax { PatternSyntax::Include => { let inner_include = root_dir.join(get_path_from_bytes(&entry.pattern)); let (inner_pats, inner_warnings) = get_patterns_from_file( &inner_include, root_dir, inspect_pattern_bytes, )?; warnings.extend(inner_warnings); inner_pats } PatternSyntax::SubInclude => { let mut sub_include = SubInclude::new( root_dir, &entry.pattern, &entry.source, )?; let (inner_patterns, inner_warnings) = get_patterns_from_file( &sub_include.path, &sub_include.root, inspect_pattern_bytes, )?; sub_include.included_patterns = inner_patterns; warnings.extend(inner_warnings); vec![IgnorePattern { syntax: PatternSyntax::ExpandedSubInclude(Box::new( sub_include, )), ..entry }] } _ => vec![entry], }) }) .flatten() .collect(); Ok((patterns, warnings)) } /// Holds all the information needed to handle a `subinclude:` pattern. #[derive(Debug, PartialEq, Eq, Clone)] pub struct SubInclude { /// Will be used for repository (hg) paths that start with this prefix. /// It is relative to the current working directory, so comparing against /// repository paths is painless. pub prefix: HgPathBuf, /// The file itself, containing the patterns pub path: PathBuf, /// Folder in the filesystem where this it applies pub root: PathBuf, pub included_patterns: Vec, } impl SubInclude { pub fn new( root_dir: &Path, pattern: &[u8], source: &Path, ) -> Result { let normalized_source = normalize_path_bytes(&get_bytes_from_path(source)); let source_root = get_path_from_bytes(&normalized_source); let source_root = source_root.parent().unwrap_or_else(|| source_root.deref()); let path = source_root.join(get_path_from_bytes(pattern)); let new_root = path.parent().unwrap_or_else(|| path.deref()); let prefix = canonical_path(root_dir, root_dir, new_root)?; Ok(Self { prefix: path_to_hg_path_buf(prefix).map(|mut p| { if !p.is_empty() { p.push_byte(b'/'); } p })?, path: path.to_owned(), root: new_root.to_owned(), included_patterns: Vec::new(), }) } } /// Separate and pre-process subincludes from other patterns for the "ignore" /// phase. pub fn filter_subincludes( ignore_patterns: Vec, ) -> Result<(Vec, Vec), HgPathError> { let mut subincludes = vec![]; let mut others = vec![]; for pattern in ignore_patterns { if let PatternSyntax::ExpandedSubInclude(sub_include) = pattern.syntax { subincludes.push(*sub_include); } else { others.push(pattern) } } Ok((subincludes, others)) } #[cfg(test)] mod tests { use super::*; use pretty_assertions::assert_eq; #[test] fn escape_pattern_test() { let untouched = br#"!"%',/0123456789:;<=>@ABCDEFGHIJKLMNOPQRSTUVWXYZ_`abcdefghijklmnopqrstuvwxyz"#; assert_eq!(escape_pattern(untouched), untouched.to_vec()); // All escape codes assert_eq!( escape_pattern(br#"()[]{}?*+-|^$\\.&~#\t\n\r\v\f"#), br#"\(\)\[\]\{\}\?\*\+\-\|\^\$\\\\\.\&\~\#\\t\\n\\r\\v\\f"# .to_vec() ); } #[test] fn glob_test() { assert_eq!(glob_to_re(br#"?"#), br#"."#); assert_eq!(glob_to_re(br#"*"#), br#"[^/]*"#); assert_eq!(glob_to_re(br#"**"#), br#".*"#); assert_eq!(glob_to_re(br#"**/a"#), br#"(?:.*/)?a"#); assert_eq!(glob_to_re(br#"a/**/b"#), br#"a/(?:.*/)?b"#); assert_eq!(glob_to_re(br#"[a*?!^][^b][!c]"#), br#"[a*?!^][\^b][^c]"#); assert_eq!(glob_to_re(br#"{a,b}"#), br#"(?:a|b)"#); assert_eq!(glob_to_re(br#".\*\?"#), br#"\.\*\?"#); } #[test] fn test_parse_pattern_file_contents() { let lines = b"syntax: glob\n*.elc"; assert_eq!( parse_pattern_file_contents( lines, Path::new("file_path"), None, false, true, ) .unwrap() .0, vec![IgnorePattern::new( PatternSyntax::RelGlob, b"*.elc", Path::new("file_path") )], ); let lines = b"syntax: include\nsyntax: glob"; assert_eq!( parse_pattern_file_contents( lines, Path::new("file_path"), None, false, true, ) .unwrap() .0, vec![] ); let lines = b"glob:**.o"; assert_eq!( parse_pattern_file_contents( lines, Path::new("file_path"), None, false, true, ) .unwrap() .0, vec![IgnorePattern::new( PatternSyntax::RelGlob, b"**.o", Path::new("file_path") )] ); } #[test] fn test_build_single_regex() { assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RelGlob, b"rust/target/", Path::new("") )) .unwrap(), Some(br"(?:.*/)?rust/target(?:/|$)".to_vec()), ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::Regexp, br"rust/target/\d+", Path::new("") )) .unwrap(), Some(br"rust/target/\d+".to_vec()), ); } #[test] fn test_build_single_regex_shortcut() { assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RootGlob, b"", Path::new("") )) .unwrap(), None, ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RootGlob, b"whatever", Path::new("") )) .unwrap(), None, ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RootGlob, b"*.o", Path::new("") )) .unwrap(), Some(br"[^/]*\.o(?:/|$)".to_vec()), ); } #[test] fn test_build_single_relregex() { assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RelRegexp, b"^ba{2}r", Path::new("") )) .unwrap(), Some(b"^ba{2}r".to_vec()), ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RelRegexp, b"ba{2}r", Path::new("") )) .unwrap(), Some(b".*ba{2}r".to_vec()), ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RelRegexp, b"(?ia)ba{2}r", Path::new("") )) .unwrap(), Some(b"(?ia:.*ba{2}r)".to_vec()), ); assert_eq!( build_single_regex(&IgnorePattern::new( PatternSyntax::RelRegexp, b"(?ia)^ba{2}r", Path::new("") )) .unwrap(), Some(b"(?ia:^ba{2}r)".to_vec()), ); } }