Expose block number in seal_random (#8329)

* Allow contract callable functions to specify the module

* Add new version of `seal_random`

* Fix overlong lines

* Fix benchmarking code

* Update README.md

* Replace Module by Pallet

substrate/frame/contracts/src/wasm/env_def/macros.rs

@@ -43,21 +43,23 @@ macro_rules! gen_signature {
 
 macro_rules! gen_signature_dispatch {
 	(
+		$needle_module:ident,
 		$needle_name:ident,
 		$needle_sig:ident ;
+		$module:ident,
 		$name:ident
-		( $ctx:ident $( , $names:ident : $params:ty )* ) $( -> $returns:ty )* , $($rest:tt)* ) => {
-		if stringify!($name).as_bytes() == $needle_name {
+		( $ctx:ident $( , $names:ident : $params:ty )* ) $( -> $returns:ty )* , $($rest:tt)*
+	) => {
+		if stringify!($module).as_bytes() == $needle_module && stringify!($name).as_bytes() == $needle_name {
 			let signature = gen_signature!( ( $( $params ),* ) $( -> $returns )* );
 			if $needle_sig == &signature {
 				return true;
 			}
 		} else {
-			gen_signature_dispatch!($needle_name, $needle_sig ; $($rest)*);
+			gen_signature_dispatch!($needle_module, $needle_name, $needle_sig ; $($rest)*);
 		}
 	};
-	( $needle_name:ident, $needle_sig:ident ; ) => {
-	};
+	( $needle_module:ident, $needle_name:ident, $needle_sig:ident ; ) => {};
 }
 
 /// Unmarshall arguments and then execute `body` expression and return its result.
@@ -151,10 +153,11 @@ macro_rules! register_func {
 	( $reg_cb:ident, < E: $seal_ty:tt > ; ) => {};
 
 	( $reg_cb:ident, < E: $seal_ty:tt > ;
-		$name:ident ( $ctx:ident $( , $names:ident : $params:ty )* )
+		$module:ident $name:ident ( $ctx:ident $( , $names:ident : $params:ty )* )
 		$( -> $returns:ty )* => $body:tt $($rest:tt)*
 	) => {
 		$reg_cb(
+			stringify!($module).as_bytes(),
 			stringify!($name).as_bytes(),
 			{
 				define_func!(
@@ -176,14 +179,17 @@ macro_rules! register_func {
 /// and reject the code if any imported function has a mismatched signature.
 macro_rules! define_env {
 	( $init_name:ident , < E: $seal_ty:tt > ,
-		$( $name:ident ( $ctx:ident $( , $names:ident : $params:ty )* )
+		$( [$module:ident] $name:ident ( $ctx:ident $( , $names:ident : $params:ty )* )
 			$( -> $returns:ty )* => $body:tt , )*
 	) => {
 		pub struct $init_name;
 
 		impl $crate::wasm::env_def::ImportSatisfyCheck for $init_name {
-			fn can_satisfy(name: &[u8], func_type: &parity_wasm::elements::FunctionType) -> bool {
-				gen_signature_dispatch!( name, func_type ; $( $name ( $ctx $(, $names : $params )* ) $( -> $returns )* , )* );
+			fn can_satisfy(module: &[u8], name: &[u8], func_type: &parity_wasm::elements::FunctionType) -> bool {
+				gen_signature_dispatch!(
+					module, name, func_type ;
+					$( $module, $name ( $ctx $(, $names : $params )* ) $( -> $returns )* , )*
+				);
 
 				return false;
 			}
@@ -195,8 +201,12 @@ macro_rules! define_env {
 				sp_core::crypto::UncheckedFrom<<E::T as frame_system::Config>::Hash> +
 					AsRef<[u8]>
 		{
-			fn impls<F: FnMut(&[u8], $crate::wasm::env_def::HostFunc<E>)>(f: &mut F) {
-				register_func!(f, < E: $seal_ty > ; $( $name ( $ctx $( , $names : $params )* ) $( -> $returns)* => $body )* );
+			fn impls<F: FnMut(&[u8], &[u8], $crate::wasm::env_def::HostFunc<E>)>(f: &mut F) {
+				register_func!(
+					f,
+					< E: $seal_ty > ;
+					$( $module $name ( $ctx $( , $names : $params )* ) $( -> $returns)* => $body )*
+				);
 			}
 		}
 	};
@@ -327,7 +337,7 @@ mod tests {
 		use crate::wasm::env_def::ImportSatisfyCheck;
 
 		define_env!(Env, <E: Ext>,
-			seal_gas( _ctx, amount: u32 ) => {
+			[seal0] seal_gas( _ctx, amount: u32 ) => {
 				let amount = Weight::from(amount);
 				if !amount.is_zero() {
 					Ok(())
@@ -337,7 +347,11 @@ mod tests {
 			},
 		);
 
-		assert!(Env::can_satisfy(b"seal_gas", &FunctionType::new(vec![ValueType::I32], None)));
-		assert!(!Env::can_satisfy(b"not_exists", &FunctionType::new(vec![], None)));
+		assert!(
+			Env::can_satisfy(b"seal0", b"seal_gas",&FunctionType::new(vec![ValueType::I32], None))
+		);
+		assert!(
+			!Env::can_satisfy(b"seal0", b"not_exists", &FunctionType::new(vec![], None))
+		);
 	}
 }

substrate/frame/contracts/src/wasm/env_def/mod.rs

@@ -74,7 +74,7 @@ pub type HostFunc<E> =
 	) -> Result<sp_sandbox::ReturnValue, sp_sandbox::HostError>;
 
 pub trait FunctionImplProvider<E: Ext> {
-	fn impls<F: FnMut(&[u8], HostFunc<E>)>(f: &mut F);
+	fn impls<F: FnMut(&[u8], &[u8], HostFunc<E>)>(f: &mut F);
 }
 
 /// This trait can be used to check whether the host environment can satisfy
@@ -83,5 +83,5 @@ pub trait ImportSatisfyCheck {
 	/// Returns `true` if the host environment contains a function with
 	/// the specified name and its type matches to the given type, or `false`
 	/// otherwise.
-	fn can_satisfy(name: &[u8], func_type: &FunctionType) -> bool;
+	fn can_satisfy(module: &[u8], name: &[u8], func_type: &FunctionType) -> bool;
 }