1 files changed, 37 insertions, 0 deletions
diff --git a/src/attr.rs b/src/attr.rs
new file mode 100644
index 0000000..dca1511
--- /dev/null
+++ b/src/attr.rs
@@ -0,0 +1,37 @@
+use syn::parse::{Error, Result};
+use syn::{parse_quote, Attribute, Path};
+
+// #[linkme(crate = path::to::linkme)]
+pub(crate) fn linkme_path(attrs: &mut Vec<Attribute>) -> Result<Path> {
+    let mut linkme_path = None;
+    let mut errors: Option<Error> = None;
+
+    attrs.retain(|attr| {
+        if !attr.path().is_ident("linkme") {
+            return true;
+        }
+        if let Err(err) = attr.parse_nested_meta(|meta| {
+            if meta.path.is_ident("crate") {
+                if linkme_path.is_some() {
+                    return Err(meta.error("duplicate linkme crate attribute"));
+                }
+                let path = meta.value()?.call(Path::parse_mod_style)?;
+                linkme_path = Some(path);
+                Ok(())
+            } else {
+                Err(meta.error("unsupported linkme attribute"))
+            }
+        }) {
+            match &mut errors {
+                None => errors = Some(err),
+                Some(errors) => errors.combine(err),
+            }
+        }
+        false
+    });
+
+    match errors {
+        None => Ok(linkme_path.unwrap_or_else(|| parse_quote!(::linkme))),
+        Some(errors) => Err(errors),
+    }
+}