Add pallet dev mode

frame/support/procedural/src/pallet/mod.rs

@@ -31,21 +31,35 @@ mod parse;
 pub use parse::Def;
 use syn::spanned::Spanned;
 
+mod keyword {
+	syn::custom_keyword!(dev_mode);
+}
+
 pub fn pallet(
 	attr: proc_macro::TokenStream,
 	item: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {
+	let mut dev_mode = false;
 	if !attr.is_empty() {
-		let msg =
-			"Invalid pallet macro call: expected no attributes, e.g. macro call must be just \
-			`#[frame_support::pallet]` or `#[pallet]`";
-		let span = proc_macro2::TokenStream::from(attr).span();
-		return syn::Error::new(span, msg).to_compile_error().into()
+		if let Ok(_) = syn::parse::<keyword::dev_mode>(attr.clone()) {
+			println!("dev mode detected!");
+			dev_mode = true;
+		} else {
+			let msg = "Invalid pallet macro call: unexpected attribute. Macro call must be \
+				bare, such as `#[frame_support::pallet]` or `#[pallet]`, or must specify the \
+				`dev_mode` attribute, such as `#[frame_support::pallet(dev_mode)]` or \
+				#[pallet(dev_mode)]. No other attributes are supported at this time.";
+			let span = proc_macro2::TokenStream::from(attr).span();
+			return syn::Error::new(span, msg).to_compile_error().into()
+		}
 	}
 
 	let item = syn::parse_macro_input!(item as syn::ItemMod);
-	match parse::Def::try_from(item) {
-		Ok(def) => expand::expand(def).into(),
+	match parse::Def::try_from(item, dev_mode) {
+		Ok(mut def) => {
+			def.dev_mode = dev_mode;
+			expand::expand(def).into()
+		},
 		Err(e) => e.to_compile_error().into(),
 	}
 }

frame/support/procedural/src/pallet/parse/call.rs

@@ -144,6 +144,7 @@ impl CallDef {
 		attr_span: proc_macro2::Span,
 		index: usize,
 		item: &mut syn::Item,
+		dev_mode: bool,
 	) -> syn::Result<Self> {
 		let item_impl = if let syn::Item::Impl(item) = item {
 			item
@@ -213,6 +214,15 @@ impl CallDef {
 						},
 					);
 
+				if weight_attrs.is_empty() && dev_mode {
+					// inject a default O(1) weight when dev mode is enabled and no weight has
+					// been specified on the call
+					let empty_weight: syn::Expr =
+						syn::parse(quote::quote!(T::WeightInfo::create()).into())
+							.expect("we are parsing a quoted string; qed");
+					weight_attrs.push(FunctionAttr::Weight(empty_weight));
+				}
+
 				if weight_attrs.len() != 1 {
 					let msg = if weight_attrs.is_empty() {
 						"Invalid pallet::call, requires weight attribute i.e. `#[pallet::weight($expr)]`"

frame/support/procedural/src/pallet/parse/mod.rs

@@ -59,10 +59,11 @@ pub struct Def {
 	pub type_values: Vec<type_value::TypeValueDef>,
 	pub frame_system: syn::Ident,
 	pub frame_support: syn::Ident,
+	pub dev_mode: bool,
 }
 
 impl Def {
-	pub fn try_from(mut item: syn::ItemMod) -> syn::Result<Self> {
+	pub fn try_from(mut item: syn::ItemMod, dev_mode: bool) -> syn::Result<Self> {
 		let frame_system = generate_crate_access_2018("frame-system")?;
 		let frame_support = generate_crate_access_2018("frame-support")?;
 
@@ -106,7 +107,7 @@ impl Def {
 					hooks = Some(m);
 				},
 				Some(PalletAttr::RuntimeCall(span)) if call.is_none() =>
-					call = Some(call::CallDef::try_from(span, index, item)?),
+					call = Some(call::CallDef::try_from(span, index, item, dev_mode)?),
 				Some(PalletAttr::Error(span)) if error.is_none() =>
 					error = Some(error::ErrorDef::try_from(span, index, item)?),
 				Some(PalletAttr::RuntimeEvent(span)) if event.is_none() =>
@@ -124,7 +125,7 @@ impl Def {
 				Some(PalletAttr::Inherent(_)) if inherent.is_none() =>
 					inherent = Some(inherent::InherentDef::try_from(index, item)?),
 				Some(PalletAttr::Storage(span)) =>
-					storages.push(storage::StorageDef::try_from(span, index, item)?),
+					storages.push(storage::StorageDef::try_from(span, index, item, dev_mode)?),
 				Some(PalletAttr::ValidateUnsigned(_)) if validate_unsigned.is_none() => {
 					let v = validate_unsigned::ValidateUnsignedDef::try_from(index, item)?;
 					validate_unsigned = Some(v);
@@ -173,6 +174,7 @@ impl Def {
 			type_values,
 			frame_system,
 			frame_support,
+			dev_mode,
 		};
 
 		def.check_instance_usage()?;

frame/support/procedural/src/pallet/parse/storage.rs

@@ -678,6 +678,7 @@ impl StorageDef {
 		attr_span: proc_macro2::Span,
 		index: usize,
 		item: &mut syn::Item,
+		dev_mode: bool,
 	) -> syn::Result<Self> {
 		let item = if let syn::Item::Type(item) = item {
 			item
@@ -686,9 +687,14 @@ impl StorageDef {
 		};
 
 		let attrs: Vec<PalletStorageAttr> = helper::take_item_pallet_attrs(&mut item.attrs)?;
-		let PalletStorageAttrInfo { getter, rename_as, unbounded, whitelisted } =
+		let PalletStorageAttrInfo { getter, rename_as, mut unbounded, whitelisted } =
 			PalletStorageAttrInfo::from_attrs(attrs)?;
 
+		if dev_mode {
+			// set all storages to be unbounded if dev_mode is enabled
+			unbounded = true;
+		}
+
 		let cfg_attrs = helper::get_item_cfg_attrs(&item.attrs);
 
 		let instances = vec![helper::check_type_def_gen(&item.generics, item.ident.span())?];