Add a path to the parent dir of rustfmt.toml as a prefix to paths in ignore

src/config/config_type.rs

@@ -141,7 +141,7 @@ macro_rules! create_config {
                 ConfigWasSet(self)
             }
 
-            fn fill_from_parsed_config(mut self, parsed: PartialConfig) -> Config {
+            fn fill_from_parsed_config(mut self, parsed: PartialConfig, dir: &Path) -> Config {
             $(
                 if let Some(val) = parsed.$i {
                     if self.$i.3 {
@@ -160,6 +160,7 @@ macro_rules! create_config {
             )+
                 self.set_heuristics();
                 self.set_license_template();
+                self.set_ignore(dir);
                 self
             }
 
@@ -286,6 +287,9 @@ macro_rules! create_config {
                 }
             }
 
+            fn set_ignore(&mut self, dir: &Path) {
+                self.ignore.2.add_prefix(dir);
+            }
 
             /// Returns `true` if the config key was explicitly set and is the default value.
             pub fn is_default(&self, key: &str) -> bool {

src/config/mod.rs

@@ -190,7 +190,8 @@ impl Config {
         let mut file = File::open(&file_path)?;
         let mut toml = String::new();
         file.read_to_string(&mut toml)?;
-        Config::from_toml(&toml).map_err(|err| Error::new(ErrorKind::InvalidData, err))
+        Config::from_toml(&toml, file_path.parent().unwrap())
+            .map_err(|err| Error::new(ErrorKind::InvalidData, err))
     }
 
     /// Resolves the config for input in `dir`.
@@ -252,7 +253,7 @@ impl Config {
         }
     }
 
-    pub(crate) fn from_toml(toml: &str) -> Result<Config, String> {
+    pub(crate) fn from_toml(toml: &str, dir: &Path) -> Result<Config, String> {
         let parsed: ::toml::Value = toml
             .parse()
             .map_err(|e| format!("Could not parse TOML: {}", e))?;
@@ -271,7 +272,7 @@ impl Config {
                 if !err.is_empty() {
                     eprint!("{}", err);
                 }
-                Ok(Config::default().fill_from_parsed_config(parsed_config))
+                Ok(Config::default().fill_from_parsed_config(parsed_config, dir))
             }
             Err(e) => {
                 err.push_str("Error: Decoding config file failed:\n");
@@ -425,7 +426,7 @@ mod test {
 
     #[test]
     fn test_was_set() {
-        let config = Config::from_toml("hard_tabs = true").unwrap();
+        let config = Config::from_toml("hard_tabs = true", Path::new("")).unwrap();
 
         assert_eq!(config.was_set().hard_tabs(), true);
         assert_eq!(config.was_set().verbose(), false);

src/config/options.rs

@@ -1,7 +1,9 @@
 use std::collections::{hash_set, HashSet};
+use std::fmt;
 use std::path::{Path, PathBuf};
 
 use atty;
+use serde::de::{Deserialize, Deserializer, SeqAccess, Visitor};
 
 use crate::config::config_type::ConfigType;
 use crate::config::lists::*;
@@ -396,33 +398,63 @@ impl Default for EmitMode {
 }
 
 /// A set of directories, files and modules that rustfmt should ignore.
-#[derive(Default, Deserialize, Serialize, Clone, Debug, PartialEq)]
-pub struct IgnoreList(HashSet<PathBuf>);
+#[derive(Default, Serialize, Clone, Debug, PartialEq)]
+pub struct IgnoreList {
+    /// A set of path specified in rustfmt.toml.
+    #[serde(flatten)]
+    path_set: HashSet<PathBuf>,
+    /// A path to rustfmt.toml.
+    #[serde(skip_serializing)]
+    rustfmt_toml_path: PathBuf,
+}
+
+impl<'de> Deserialize<'de> for IgnoreList {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct HashSetVisitor;
+        impl<'v> Visitor<'v> for HashSetVisitor {
+            type Value = HashSet<PathBuf>;
+
+            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+                formatter.write_str("a sequence of path")
+            }
+
+            fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+            where
+                A: SeqAccess<'v>,
+            {
+                let mut path_set = HashSet::new();
+                while let Some(elem) = seq.next_element()? {
+                    path_set.insert(elem);
+                }
+                Ok(path_set)
+            }
+        }
+        Ok(IgnoreList {
+            path_set: deserializer.deserialize_seq(HashSetVisitor)?,
+            rustfmt_toml_path: PathBuf::new(),
+        })
+    }
+}
 
 impl<'a> IntoIterator for &'a IgnoreList {
     type Item = &'a PathBuf;
     type IntoIter = hash_set::Iter<'a, PathBuf>;
 
     fn into_iter(self) -> Self::IntoIter {
-        self.0.iter()
+        self.path_set.iter()
     }
 }
 
 impl IgnoreList {
     pub fn add_prefix(&mut self, dir: &Path) {
-        self.0 = self
-            .0
-            .iter()
-            .map(|s| {
-                if s.has_root() {
-                    s.clone()
-                } else {
-                    let mut path = PathBuf::from(dir);
-                    path.push(s);
-                    path
-                }
-            })
-            .collect();
+        self.rustfmt_toml_path = dir.to_path_buf();
+    }
+
+    pub fn rustfmt_toml_path(&self) -> &Path {
+        &self.rustfmt_toml_path
     }
 }
 

src/formatting.rs

@@ -67,6 +67,14 @@ fn format_project<T: FormatHandler>(
     let main_file = input.file_name();
     let input_is_stdin = main_file == FileName::Stdin;
 
+    let ignore_path_set = match IgnorePathSet::from_ignore_list(&config.ignore()) {
+        Ok(set) => set,
+        Err(e) => return Err(ErrorKind::InvalidGlobPattern(e)),
+    };
+    if config.skip_children() && ignore_path_set.is_match(&main_file) {
+        return Ok(FormatReport::new());
+    }
+
     // Parse the crate.
     let source_map = Rc::new(SourceMap::new(FilePathMapping::empty()));
     let mut parse_session = make_parse_sess(source_map.clone(), config);
@@ -91,11 +99,6 @@ fn format_project<T: FormatHandler>(
     parse_session.span_diagnostic = Handler::with_emitter(true, None, silent_emitter);
 
     let mut context = FormatContext::new(&krate, report, parse_session, config, handler);
-    let ignore_path_set = match IgnorePathSet::from_ignore_list(&config.ignore()) {
-        Ok(set) => set,
-        Err(e) => return Err(ErrorKind::InvalidGlobPattern(e)),
-    };
-
     let files = modules::ModResolver::new(
         context.parse_session.source_map(),
         directory_ownership.unwrap_or(parse::DirectoryOwnership::UnownedViaMod(false)),

src/ignore_path.rs

@@ -1,5 +1,4 @@
 use ignore::{self, gitignore};
-use std::path::PathBuf;
 
 use crate::config::{FileName, IgnoreList};
 
@@ -9,7 +8,7 @@ pub struct IgnorePathSet {
 
 impl IgnorePathSet {
     pub fn from_ignore_list(ignore_list: &IgnoreList) -> Result<Self, ignore::Error> {
-        let mut ignore_builder = gitignore::GitignoreBuilder::new(PathBuf::from(""));
+        let mut ignore_builder = gitignore::GitignoreBuilder::new(ignore_list.rustfmt_toml_path());
 
         for ignore_path in ignore_list {
             ignore_builder.add_line(None, ignore_path.to_str().unwrap())?;
@@ -33,16 +32,19 @@ impl IgnorePathSet {
 
 #[cfg(test)]
 mod test {
+    use std::path::{Path, PathBuf};
+
     use crate::config::{Config, FileName};
     use crate::ignore_path::IgnorePathSet;
-    use std::path::PathBuf;
 
     #[test]
     fn test_ignore_path_set() {
         match option_env!("CFG_RELEASE_CHANNEL") {
             // this test requires nightly
             None | Some("nightly") => {
-                let config = Config::from_toml(r#"ignore = ["foo.rs", "bar_dir/*"]"#).unwrap();
+                let config =
+                    Config::from_toml(r#"ignore = ["foo.rs", "bar_dir/*"]"#, Path::new(""))
+                        .unwrap();
                 let ignore_path_set = IgnorePathSet::from_ignore_list(&config.ignore()).unwrap();
 
                 assert!(ignore_path_set.is_match(&FileName::Real(PathBuf::from("src/foo.rs"))));

src/test/mod.rs

@@ -564,7 +564,7 @@ fn get_config(config_file: Option<&Path>) -> Config {
         .read_to_string(&mut def_config)
         .expect("Couldn't read config");
 
-    Config::from_toml(&def_config).expect("invalid TOML")
+    Config::from_toml(&def_config, Path::new("tests/config/")).expect("invalid TOML")
 }
 
 // Reads significant comments of the form: `// rustfmt-key: value` into a hash map.