1 files changed, 70 insertions, 0 deletions
diff --git a/tools/profiler/rust-api/macros/src/lib.rs b/tools/profiler/rust-api/macros/src/lib.rs
new file mode 100644
index 0000000000..aca65cced3
--- /dev/null
+++ b/tools/profiler/rust-api/macros/src/lib.rs
@@ -0,0 +1,70 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#![deny(warnings)]
+
+//! A procedural macro as a syntactical sugar to `gecko_profiler_label!` macro.
+//! You can use this macro on top of functions to automatically append the
+//! label frame to the function.
+//!
+//! Example usage:
+//! ```rust
+//! #[gecko_profiler_fn_label(DOM)]
+//! fn foo(bar: u32) -> u32 {
+//!     bar
+//! }
+//!
+//! #[gecko_profiler_fn_label(Javascript, IonMonkey)]
+//! pub fn bar(baz: i8) -> i8 {
+//!     baz
+//! }
+//! ```
+//!
+//! See the documentation of `gecko_profiler_label!` macro to learn more about
+//! its parameters.
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, ItemFn};
+
+#[proc_macro_attribute]
+pub fn gecko_profiler_fn_label(attrs: TokenStream, input: TokenStream) -> TokenStream {
+    let mut attr_args = Vec::new();
+    let attr_parser = syn::meta::parser(|meta| {
+        attr_args.push(meta.path);
+        Ok(())
+    });
+    parse_macro_input!(attrs with attr_parser);
+    let input = parse_macro_input!(input as ItemFn);
+
+    if attr_args.is_empty() || attr_args.len() > 2 {
+        panic!("Expected one or two arguments as ProfilingCategory or ProfilingCategoryPair but {} arguments provided!", attr_args.len());
+    }
+
+    let category_name = &attr_args[0];
+    // Try to get the subcategory if possible. Otherwise, use `None`.
+    let subcategory_if_provided = match attr_args.get(1) {
+        Some(subcategory) => quote!(, #subcategory),
+        None => quote!(),
+    };
+
+    let ItemFn {
+        attrs,
+        vis,
+        sig,
+        block,
+    } = input;
+    let stmts = &block.stmts;
+
+    let new_fn = quote! {
+        #(#attrs)* #vis #sig {
+          gecko_profiler_label!(#category_name#subcategory_if_provided);
+          #(#stmts)*
+        }
+    };
+
+    new_fn.into()
+}