diff --git a/rust/pin-init/internal/src/diagnostics.rs b/rust/pin-init/internal/src/diagnostics.rs
new file mode 100644
index 000000000000..555876c01bab
--- /dev/null
+++ b/rust/pin-init/internal/src/diagnostics.rs
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use std::fmt::Display;
+
+use proc_macro2::TokenStream;
+use syn::{spanned::Spanned, Error};
+
+pub(crate) struct DiagCtxt(TokenStream);
+pub(crate) struct ErrorGuaranteed(());
+
+impl DiagCtxt {
+    #[expect(dead_code)]
+    pub(crate) fn error(&mut self, span: impl Spanned, msg: impl Display) -> ErrorGuaranteed {
+        let error = Error::new(span.span(), msg);
+        self.0.extend(error.into_compile_error());
+        ErrorGuaranteed(())
+    }
+
+    #[expect(dead_code)]
+    pub(crate) fn with(
+        fun: impl FnOnce(&mut DiagCtxt) -> Result<TokenStream, ErrorGuaranteed>,
+    ) -> TokenStream {
+        let mut dcx = Self(TokenStream::new());
+        match fun(&mut dcx) {
+            Ok(mut stream) => {
+                stream.extend(dcx.0);
+                stream
+            }
+            Err(ErrorGuaranteed(())) => dcx.0,
+        }
+    }
+}
diff --git a/rust/pin-init/internal/src/lib.rs b/rust/pin-init/internal/src/lib.rs
index 4c4dc639ce82..0e1a4724549d 100644
--- a/rust/pin-init/internal/src/lib.rs
+++ b/rust/pin-init/internal/src/lib.rs
@@ -12,6 +12,7 @@
 
 use proc_macro::TokenStream;
 
+mod diagnostics;
 mod helpers;
 mod pin_data;
 mod pinned_drop;