Remove deprecated host functions (#5038)

Sadly we need to keep one function `ext_blake2_256`. This function is
manually defined in `sp-core`.

substrate/primitives/runtime-interface/test-wasm/src/lib.rs

@@ -105,23 +105,6 @@ pub trait TestApi {
 	}
 }
 
-/// Two random external functions from the old runtime interface.
-/// This ensures that we still inherently export these functions from the host and that we are still
-/// compatible with old wasm runtimes.
-#[cfg(not(feature = "std"))]
-extern "C" {
-	pub fn ext_clear_storage(key_data: *const u8, key_len: u32);
-	pub fn ext_keccak_256(data: *const u8, len: u32, out: *mut u8);
-}
-
-/// Make sure the old runtime interface needs to be imported.
-#[no_mangle]
-#[cfg(not(feature = "std"))]
-pub fn force_old_runtime_interface_import() {
-	unsafe { ext_clear_storage(sp_std::ptr::null(), 0); }
-	unsafe { ext_keccak_256(sp_std::ptr::null(), 0, sp_std::ptr::null_mut()); }
-}
-
 /// This function is not used, but we require it for the compiler to include `sp-io`.
 /// `sp-io` is required for its panic and oom handler.
 #[no_mangle]
@@ -248,4 +231,14 @@ wasm_export_functions! {
 		}
 		assert_eq!(0, len);
 	}
+
+	fn test_ext_blake2_256() {
+		use sp_core::Hasher;
+
+		let data = "hey, hash me please!";
+		let hash = sp_core::Blake2Hasher::hash(data.as_bytes());
+
+		let expected = sp_io::hashing::blake2_256(data.as_bytes());
+		assert_eq!(&expected, hash.as_ref());
+	}
 }

substrate/primitives/runtime-interface/test/src/lib.rs

@@ -33,7 +33,6 @@ fn call_wasm_method<HF: HostFunctionsT>(method: &str) -> TestExternalities {
 		(
 			HF,
 			sp_io::SubstrateHostFunctions,
-			sc_executor::deprecated_host_interface::SubstrateExternals
 		)
 	>(
 		method,
@@ -128,3 +127,8 @@ fn test_encoded_return_value_memory_is_freed() {
 fn test_array_return_value_memory_is_freed() {
 	call_wasm_method::<HostFunctions>("test_array_return_value_memory_is_freed");
 }
+
+#[test]
+fn test_ext_blake2_256() {
+	call_wasm_method::<HostFunctions>("test_ext_blake2_256");
+}