1 files changed, 118 insertions, 0 deletions
diff --git a/src/tools/rustfmt/src/config/macro_names.rs b/src/tools/rustfmt/src/config/macro_names.rs
new file mode 100644
index 000000000..26ad78d6d
--- /dev/null
+++ b/src/tools/rustfmt/src/config/macro_names.rs
@@ -0,0 +1,118 @@
+//! This module contains types and functions to support formatting specific macros.
+
+use itertools::Itertools;
+use std::{fmt, str};
+
+use serde::{Deserialize, Serialize};
+use serde_json as json;
+use thiserror::Error;
+
+/// Defines the name of a macro.
+#[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
+pub struct MacroName(String);
+
+impl MacroName {
+    pub fn new(other: String) -> Self {
+        Self(other)
+    }
+}
+
+impl fmt::Display for MacroName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl From<MacroName> for String {
+    fn from(other: MacroName) -> Self {
+        other.0
+    }
+}
+
+/// Defines a selector to match against a macro.
+#[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
+pub enum MacroSelector {
+    Name(MacroName),
+    All,
+}
+
+impl fmt::Display for MacroSelector {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Name(name) => name.fmt(f),
+            Self::All => write!(f, "*"),
+        }
+    }
+}
+
+impl str::FromStr for MacroSelector {
+    type Err = std::convert::Infallible;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "*" => MacroSelector::All,
+            name => MacroSelector::Name(MacroName(name.to_owned())),
+        })
+    }
+}
+
+/// A set of macro selectors.
+#[derive(Clone, Debug, Default, PartialEq, Deserialize, Serialize)]
+pub struct MacroSelectors(pub Vec<MacroSelector>);
+
+impl fmt::Display for MacroSelectors {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0.iter().format(", "))
+    }
+}
+
+#[derive(Error, Debug)]
+pub enum MacroSelectorsError {
+    #[error("{0}")]
+    Json(json::Error),
+}
+
+// This impl is needed for `Config::override_value` to work for use in tests.
+impl str::FromStr for MacroSelectors {
+    type Err = MacroSelectorsError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let raw: Vec<&str> = json::from_str(s).map_err(MacroSelectorsError::Json)?;
+        Ok(Self(
+            raw.into_iter()
+                .map(|raw| {
+                    MacroSelector::from_str(raw).expect("MacroSelector from_str is infallible")
+                })
+                .collect(),
+        ))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use std::str::FromStr;
+
+    #[test]
+    fn macro_names_from_str() {
+        let macro_names = MacroSelectors::from_str(r#"["foo", "*", "bar"]"#).unwrap();
+        assert_eq!(
+            macro_names,
+            MacroSelectors(
+                [
+                    MacroSelector::Name(MacroName("foo".to_owned())),
+                    MacroSelector::All,
+                    MacroSelector::Name(MacroName("bar".to_owned()))
+                ]
+                .into_iter()
+                .collect()
+            )
+        );
+    }
+
+    #[test]
+    fn macro_names_display() {
+        let macro_names = MacroSelectors::from_str(r#"["foo", "*", "bar"]"#).unwrap();
+        assert_eq!(format!("{}", macro_names), "foo, *, bar");
+    }
+}