Commit missing matrix_sdk_common_macros folder

matrix_sdk_common_macros/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+description = "Helper macros for the Matrix SDK"
+authors = ["MTRnord <mtrnord1@gmail.com>"]
+edition = "2018"
+homepage = "https://github.com/matrix-org/matrix-rust-sdk"
+keywords = ["matrix", "chat", "messaging", "ruma"]
+license = "Apache-2.0"
+name = "matrix-sdk-common-macros"
+readme = "README.md"
+repository = "https://github.com/matrix-org/matrix-rust-sdk"
+version = "0.1.0"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = "1.0"
+quote = "1.0"

matrix_sdk_common_macros/src/lib.rs

@@ -0,0 +1,30 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, parse_quote, ItemTrait};
+
+/// Attribute to use `Send + Sync` for everything but wasm32
+#[proc_macro_attribute]
+pub fn send_sync(_attr: TokenStream, input: TokenStream) -> TokenStream {
+    // Parse the input tokens into a syntax tree
+    let mut input = parse_macro_input!(input as ItemTrait);
+
+    let send_trait_bound = parse_quote!(std::marker::Send);
+    let sync_trait_bound = parse_quote!(std::marker::Sync);
+    input.supertraits.push(send_trait_bound);
+    input.supertraits.push(sync_trait_bound);
+
+    TokenStream::from(quote!(#input))
+}
+
+/// A wasm32 compatible wrapper for the async_trait::async_trait macro
+#[proc_macro_attribute]
+pub fn async_trait(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    let attrs = r#"
+        #[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
+        #[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
+    "#;
+
+    let mut out: TokenStream = attrs.parse().unwrap();
+    out.extend(item);
+    out
+}