[contracts] API host functions: remove seal_ name prefix + enable aliasing

frame/contracts/fixtures/call_runtime.wat

@@ -1,6 +1,6 @@
 ;; This passes its input to `seal_call_runtime` and returns the return value to its caller.
 (module
-	(import "__unstable__" "seal_call_runtime" (func $seal_call_runtime (param i32 i32) (result i32)))
+	(import "__unstable__" "call_runtime" (func $call_runtime (param i32 i32) (result i32)))
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
 	(import "env" "memory" (memory 1 1))
@@ -17,7 +17,7 @@
 		)
 		;; Just use the call passed as input and store result to memory
 		(i32.store (i32.const 0)
-			(call $seal_call_runtime
+			(call $call_runtime
 				(i32.const 4)				;; Pointer where the call is stored
 				(i32.load (i32.const 0))	;; Size of the call
 			)

frame/contracts/proc-macro/src/lib.rs

@@ -181,14 +181,20 @@ impl HostFn {
 		};
 		let msg = "only #[version(<u8>)] or #[unstable] attribute is allowed.";
 		let span = item.span();
-		let item = match item {
+		let mut item = match item {
 			syn::Item::Fn(i_fn) => Ok(i_fn),
 			_ => Err(err(span, msg)),
 		}?;
 
-		let name = item.sig.ident.to_string();
-		let attrs: Vec<&syn::Attribute> =
-			item.attrs.iter().filter(|m| !m.path.is_ident("doc")).collect();
+		let attrs = &mut item.attrs;
+
+		let name = if attrs.iter().any(|a| a.path.is_ident("prefixed_alias")) {
+			"seal_".to_string() + &item.sig.ident.to_string()
+		} else {
+			item.sig.ident.to_string()
+		};
+
+		attrs.retain(|a| !(a.path.is_ident("doc") || a.path.is_ident("prefixed_alias")));
 
 		let module = match attrs.len() {
 			0 => Ok("seal0".to_string()),
@@ -306,6 +312,7 @@ impl HostFn {
 		}
 	}
 }
+
 impl EnvDef {
 	pub fn try_from(item: syn::ItemMod) -> syn::Result<Self> {
 		let span = item.span();
@@ -316,9 +323,27 @@ impl EnvDef {
 			.ok_or(err("Invalid environment definition, expected `mod` to be inlined."))?
 			.1;
 
+		let extract_fn = |i: &syn::Item| match i {
+			syn::Item::Fn(i_fn) => Some(i_fn.clone()),
+			_ => None,
+		};
+
+		let selector = |a: &syn::Attribute| a.path.is_ident("prefixed_alias");
+
+		let aliases = items
+			.iter()
+			.filter_map(extract_fn)
+			.filter(|i| i.attrs.iter().any(selector))
+			.map(|mut i| {
+				i.attrs.retain(|i| !selector(i));
+				i
+			})
+			.map(|i| HostFn::try_from(syn::Item::Fn(i)));
+
 		let host_funcs = items
 			.iter()
 			.map(|i| HostFn::try_from(i.clone()))
+			.chain(aliases)
 			.collect::<Result<Vec<_>, _>>()?;
 
 		Ok(Self { host_funcs })
@@ -484,7 +509,7 @@ fn expand_impls(def: &mut EnvDef) -> proc_macro2::TokenStream {
 /// ```nocompile
 /// #[define_env]
 /// pub mod some_env {
-/// 	fn some_host_fn(ctx: Runtime<E: Ext>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<(), TrapReason> {
+/// 	fn some_host_fn(ctx: Runtime<E>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<(), TrapReason> {
 /// 		ctx.some_host_fn(KeyType::Fix, key_ptr, value_ptr, value_len).map(|_| ())
 /// 	}
 /// }
@@ -499,17 +524,45 @@ fn expand_impls(def: &mut EnvDef) -> proc_macro2::TokenStream {
 /// #[define_env]
 /// pub mod some_env {
 /// 	#[version(1)]
-/// 	fn some_host_fn(ctx: Runtime<E: Ext>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<ReturnCode, TrapReason> {
+/// 	fn some_host_fn(ctx: Runtime<E>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<ReturnCode, TrapReason> {
+/// 		ctx.some_host_fn(KeyType::Fix, key_ptr, value_ptr, value_len).map(|_| ())
+/// 	}
+///
+/// 	#[unstable]
+/// 	fn some_host_fn(ctx: Runtime<E>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<u32, TrapReason> {
+/// 		ctx.some_host_fn(KeyType::Fix, key_ptr, value_ptr, value_len).map(|_| ())
+/// 	}
+/// }
+/// ```
+///
+/// In legacy versions of pallet_contracts, it was a naming convention that all host functions had
+/// to be named with the `seal_` prefix. For the sake of backwards compatibility, each host function
+/// now can get a such prefix-named alias function generated by marking it by the
+/// `#[prefixed_alias]` attribute:
+///
+/// ## Example
+///
+/// ```nocompile
+/// #[define_env]
+/// pub mod some_env {
+/// 	#[version(1)]
+/// 	#[prefixed_alias]
+/// 	fn some_host_fn(ctx: Runtime<E>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<ReturnCode, TrapReason> {
 /// 		ctx.some_host_fn(KeyType::Fix, key_ptr, value_ptr, value_len).map(|_| ())
 /// 	}
 ///
 /// 	#[unstable]
-/// 	fn some_host_fn(ctx: Runtime<E: Ext>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<u32, TrapReason> {
+/// 	fn some_host_fn(ctx: Runtime<E>, key_ptr: u32, value_ptr: u32, value_len: u32) -> Result<u32, TrapReason> {
 /// 		ctx.some_host_fn(KeyType::Fix, key_ptr, value_ptr, value_len).map(|_| ())
 /// 	}
 /// }
 /// ```
 ///
+/// In this example, the following host functions will be generated by the macro:
+/// - `some_host_fn()` in module `seal1`,
+/// - `seal_some_host_fn()` in module `seal1`,
+/// - `some_host_fn()` in module `__unstable__`.
+///
 /// Only following return types are allowed for the host functions defined with the macro:
 /// - `Result<(), TrapReason>`,
 /// - `Result<ReturnCode, TrapReason>`,

frame/contracts/src/benchmarking/mod.rs

@@ -920,7 +920,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_set_storage",
+				name: "set_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -968,7 +968,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_set_storage",
+				name: "set_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1016,7 +1016,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_set_storage",
+				name: "set_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1068,7 +1068,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_clear_storage",
+				name: "clear_storage",
 				params: vec![ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1115,7 +1115,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_clear_storage",
+				name: "clear_storage",
 				params: vec![ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1163,7 +1163,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_get_storage",
+				name: "get_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1217,7 +1217,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_get_storage",
+				name: "get_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1272,7 +1272,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_contains_storage",
+				name: "contains_storage",
 				params: vec![ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1319,7 +1319,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_contains_storage",
+				name: "contains_storage",
 				params: vec![ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1367,7 +1367,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_take_storage",
+				name: "take_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],
@@ -1421,7 +1421,7 @@ benchmarks! {
 			memory: Some(ImportedMemory::max::<T>()),
 			imported_functions: vec![ImportedFunction {
 				module: "__unstable__",
-				name: "seal_take_storage",
+				name: "take_storage",
 				params: vec![ValueType::I32, ValueType::I32, ValueType::I32, ValueType::I32],
 				return_type: Some(ValueType::I32),
 			}],

frame/contracts/src/wasm/mod.rs

@@ -929,7 +929,7 @@ mod tests {
 (module
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
-	(import "__unstable__" "seal_contains_storage" (func $seal_contains_storage (param i32 i32) (result i32)))
+	(import "__unstable__" "contains_storage" (func $contains_storage (param i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 
@@ -947,7 +947,7 @@ mod tests {
 		)
 		;; Call seal_clear_storage and save what it returns at 0
 		(i32.store (i32.const 0)
-			(call $seal_contains_storage
+			(call $contains_storage
 				(i32.const 8)			;; key_ptr
 				(i32.load (i32.const 4))	;; key_len
 			)
@@ -1678,11 +1678,53 @@ mod tests {
 	)
 	(func (export "deploy"))
 )
+"#;
+
+	const CODE_TIMESTAMP_NOW_UNPREFIXED: &str = r#"
+(module
+	(import "seal0" "now" (func $now (param i32 i32)))
+	(import "env" "memory" (memory 1 1))
+
+	;; size of our buffer is 32 bytes
+	(data (i32.const 32) "\20")
+
+	(func $assert (param i32)
+		(block $ok
+			(br_if $ok
+				(get_local 0)
+			)
+			(unreachable)
+		)
+	)
+
+	(func (export "call")
+		;; This stores the block timestamp in the buffer
+		(call $now (i32.const 0) (i32.const 32))
+
+		;; assert len == 8
+		(call $assert
+			(i32.eq
+				(i32.load (i32.const 32))
+				(i32.const 8)
+			)
+		)
+
+		;; assert that contents of the buffer is equal to the i64 value of 1111.
+		(call $assert
+			(i64.eq
+				(i64.load (i32.const 0))
+				(i64.const 1111)
+			)
+		)
+	)
+	(func (export "deploy"))
+)
 "#;
 
 	#[test]
 	fn now() {
 		assert_ok!(execute(CODE_TIMESTAMP_NOW, vec![], MockExt::default()));
+		assert_ok!(execute(CODE_TIMESTAMP_NOW_UNPREFIXED, vec![], MockExt::default()));
 	}
 
 	const CODE_MINIMUM_BALANCE: &str = r#"
@@ -2221,7 +2263,7 @@ mod tests {
 	#[cfg(feature = "unstable-interface")]
 	const CODE_CALL_RUNTIME: &str = r#"
 (module
-	(import "__unstable__" "seal_call_runtime" (func $seal_call_runtime (param i32 i32) (result i32)))
+	(import "__unstable__" "call_runtime" (func $call_runtime (param i32 i32) (result i32)))
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
 	(import "env" "memory" (memory 1 1))
@@ -2238,7 +2280,7 @@ mod tests {
 		)
 		;; Just use the call passed as input and store result to memory
 		(i32.store (i32.const 0)
-			(call $seal_call_runtime
+			(call $call_runtime
 				(i32.const 4)				;; Pointer where the call is stored
 				(i32.load (i32.const 0))	;; Size of the call
 			)
@@ -2350,7 +2392,7 @@ mod tests {
 (module
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
-	(import "__unstable__" "seal_set_storage" (func $seal_set_storage (param i32 i32 i32 i32) (result i32)))
+	(import "__unstable__" "set_storage" (func $set_storage (param i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 	;; [0, 4) size of input buffer
@@ -2367,7 +2409,7 @@ mod tests {
 		)
 		;; Store the passed value to the passed key and store result to memory
 		(i32.store (i32.const 168)
-			(call $seal_set_storage
+			(call $set_storage
 				(i32.const 8)				;; key_ptr
 				(i32.load (i32.const 4))		;; key_len
 				(i32.add				;; value_ptr = 8 + key_len
@@ -2421,7 +2463,7 @@ mod tests {
 (module
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
-	(import "__unstable__" "seal_get_storage" (func $seal_get_storage (param i32 i32 i32 i32) (result i32)))
+	(import "__unstable__" "get_storage" (func $get_storage (param i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 	;; [0, 4) size of input buffer (160 bytes as we copy the key+len here)
@@ -2442,7 +2484,7 @@ mod tests {
 		)
 		;; Load a storage value and result of this call into the output buffer
 		(i32.store (i32.const 168)
-			(call $seal_get_storage
+			(call $get_storage
 				(i32.const 12)			;; key_ptr
 				(i32.load (i32.const 8))	;; key_len
 				(i32.const 172)			;; Pointer to the output buffer
@@ -2515,7 +2557,7 @@ mod tests {
 (module
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
-	(import "__unstable__" "seal_clear_storage" (func $seal_clear_storage (param i32 i32) (result i32)))
+	(import "__unstable__" "clear_storage" (func $clear_storage (param i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 	;; size of input buffer
@@ -2532,7 +2574,7 @@ mod tests {
 		)
 		;; Call seal_clear_storage and save what it returns at 0
 		(i32.store (i32.const 0)
-			(call $seal_clear_storage
+			(call $clear_storage
 				(i32.const 8)			;; key_ptr
 				(i32.load (i32.const 4))	;; key_len
 			)
@@ -2601,7 +2643,7 @@ mod tests {
 (module
 	(import "seal0" "seal_return" (func $seal_return (param i32 i32 i32)))
 	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
-	(import "__unstable__" "seal_take_storage" (func $seal_take_storage (param i32 i32 i32 i32) (result i32)))
+	(import "__unstable__" "take_storage" (func $take_storage (param i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 	;; [0, 4) size of input buffer (160 bytes as we copy the key+len here)
@@ -2623,7 +2665,7 @@ mod tests {
 
 		;; Load a storage value and result of this call into the output buffer
 		(i32.store (i32.const 168)
-			(call $seal_take_storage
+			(call $take_storage
 				(i32.const 12)			;; key_ptr
 				(i32.load (i32.const 8))	;; key_len
 				(i32.const 172)			;; Pointer to the output buffer