1 files changed, 32 insertions, 0 deletions
diff --git a/ops/deno.rs b/ops/deno.rs
new file mode 100644
index 000000000..67af603e9
--- /dev/null
+++ b/ops/deno.rs
@@ -0,0 +1,32 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use proc_macro2::{Span, TokenStream};
+use proc_macro_crate::{crate_name, FoundCrate};
+use quote::quote;
+use syn::Ident;
+
+/// Identifier to the `deno_core` crate.
+///
+/// If macro called in deno_core, `crate` is used.
+/// If macro called outside deno_core, `deno_core` OR the renamed
+/// version from Cargo.toml is used.
+pub(crate) fn import() -> TokenStream {
+  let found_crate =
+    crate_name("deno_core").expect("deno_core not present in `Cargo.toml`");
+
+  match found_crate {
+    FoundCrate::Itself => {
+      // TODO(@littledivy): This won't work for `deno_core` examples
+      // since `crate` does not refer to `deno_core`.
+      // examples must re-export deno_core to make this work
+      // until Span inspection APIs are stabalized.
+      //
+      // https://github.com/rust-lang/rust/issues/54725
+      quote!(crate)
+    }
+    FoundCrate::Name(name) => {
+      let ident = Ident::new(&name, Span::call_site());
+      quote!(#ident)
+    }
+  }
+}