Merge pull request #24 from dtolnay/parserepr

Use a whitelist of recognized integer reprs
dtolnay · Oct 30, 2023 · 8a6b642 · 8a6b642
2 parents ed317c7 + 748970b
commit 8a6b642
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Showing 3 changed files with 29 additions and 4 deletions.
diff --git a/src/parse.rs b/src/parse.rs
@@ -86,10 +86,18 @@ impl Parse for Input {
         let mut repr = None;
         for attr in derive_input.attrs {
             if attr.path().is_ident("repr") {
-                if let Meta::List(_) = &attr.meta {
-                    let ty: Ident = attr.parse_args()?;
-                    repr = Some(ty);
-                    break;
+                if let Meta::List(meta) = &attr.meta {
+                    meta.parse_nested_meta(|meta| {
+                        const RECOGNIZED: &[&str] = &[
+                            "u8", "u16", "u32", "u64", "u128", "usize", "i8", "i16", "i32", "i64",
+                            "i128", "isize",
+                        ];
+                        if RECOGNIZED.iter().any(|int| meta.path.is_ident(int)) {
+                            repr = Some(meta.path.get_ident().unwrap().clone());
+                            return Ok(());
+                        }
+                        Err(meta.error("unsupported repr for serde_repr enum"))
+                    })?;
                 }
             }
         }

diff --git a/tests/ui/repr_c.rs b/tests/ui/repr_c.rs
@@ -0,0 +1,12 @@
+use serde_repr::Serialize_repr;
+
+#[derive(Serialize_repr)]
+#[repr(C)]
+enum SmallPrime {
+    Two = 2,
+    Three = 3,
+    Five = 5,
+    Seven = 7,
+}
+
+fn main() {}
diff --git a/tests/ui/repr_c.stderr b/tests/ui/repr_c.stderr
@@ -0,0 +1,5 @@
+error: unsupported repr for serde_repr enum
+ --> tests/ui/repr_c.rs:4:8
+  |
+4 | #[repr(C)]
+  |        ^