handle versions in the formats 1.71.1-beta, 1.71.1-beta.1, 1.71.1-nightly

Author: Skgland

bindgen/features.rs

@@ -416,8 +416,25 @@ impl FromStr for RustTarget {
             return Ok(Self::Nightly);
         }
 
-        let Some((major_str, tail)) = input.split_once('.') else {
-            return Err(invalid_input(input, "accepted values are of the form \"1.71\", \"1.71.1\" or \"nightly\"." ) );
+        let (version, pre_release) =
+            if let Some((version, pre_release)) = input.split_once('-') {
+                (version, pre_release)
+            } else {
+                (input, "")
+            };
+
+        const MSG: &str = r#"accepted values are of the form "1.71", "1.71.1" , "1.71.1-beta", "1.71.1-beta.1", "1.71.1-nightly" or "nightly"."#;
+
+        if !(pre_release.is_empty() /* stable */
+            || pre_release == "beta"
+            || pre_release.starts_with("beta.")
+            || pre_release == "nightly")
+        {
+            return Err(invalid_input(input, MSG));
+        }
+
+        let Some((major_str, tail)) = version.split_once('.') else {
+            return Err(invalid_input(input, MSG));
         };
 
         if major_str != "1" {
@@ -427,7 +444,7 @@ impl FromStr for RustTarget {
             ));
         }
 
-        let (minor, patch) = if let Some((minor_str, patch_str)) =
+        let (mut minor, mut patch) = if let Some((minor_str, patch_str)) =
             tail.split_once('.')
         {
             let Ok(minor) = minor_str.parse::<u64>() else {
@@ -444,6 +461,12 @@ impl FromStr for RustTarget {
             (minor, 0)
         };
 
+        if pre_release == "nightly" {
+            // treat nightly as incomplete and therefore as the previous maximaly patched stable
+            minor -= 1;
+            patch = u64::MAX;
+        }
+
         Self::stable(minor, patch).map_err(|err| invalid_input(input, err))
     }
 }
@@ -519,7 +542,9 @@ mod test {
         // Two targets are equivalent if they enable the same set of features
         let expected = RustFeatures::new_with_latest_edition(expected);
         let found = RustFeatures::new_with_latest_edition(
-            input.parse::<RustTarget>().unwrap(),
+            input.parse::<RustTarget>().unwrap_or_else(|_| {
+                panic!("{input} should parse as a valid target")
+            }),
         );
         assert_eq!(
             expected,
@@ -542,6 +567,9 @@ mod test {
         test_target("1.71.1", RustTarget::Stable_1_71);
         test_target("1.72", RustTarget::Stable_1_71);
         test_target("1.73", RustTarget::Stable_1_73);
+        test_target("1.82.0-beta", RustTarget::Stable_1_82);
+        test_target("1.82.0-beta.1", RustTarget::Stable_1_82);
+        test_target("1.83.1-nightly", RustTarget::Stable_1_82);
         test_target("1.18446744073709551615", LATEST_STABLE_RUST);
         test_target("nightly", RustTarget::Nightly);
     }