Implement runtime version checks in set_code (#4548)

* Implement runtime version checks in `set_code`

Check that the new runtime code given to `set_code` fullfills some
requirements:

- `spec_name` matches
- `spec_version` does not decreases
- `impl_version` does not decreases
- Either `spec_version` and `impl_version` increase

* Make tests almost work

* Some fixes after master merge

* Fix tests

* Add missed file

* Make depedency check happy?

* Remove leftover `sc-executor`

* AHHHHH

* Reset debug stuff

* Remove some 'static

* More 'static

* Some docs

* Update `Cargo.lock`

substrate/primitives/runtime/src/runtime_string.rs

@@ -0,0 +1,117 @@
+// Copyright 2020 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use codec::{Encode, Decode};
+use sp_core::RuntimeDebug;
+use sp_std::vec::Vec;
+
+/// A string that wraps a `&'static str` in the runtime and `String`/`Vec<u8>` on decode.
+#[derive(Eq, RuntimeDebug, Clone)]
+pub enum RuntimeString {
+	/// The borrowed mode that wraps a `&'static str`.
+	Borrowed(&'static str),
+	/// The owned mode that wraps a `String`.
+	#[cfg(feature = "std")]
+	Owned(String),
+	/// The owned mode that wraps a `Vec<u8>`.
+	#[cfg(not(feature = "std"))]
+	Owned(Vec<u8>),
+}
+
+impl From<&'static str> for RuntimeString {
+	fn from(data: &'static str) -> Self {
+		Self::Borrowed(data)
+	}
+}
+
+#[cfg(feature = "std")]
+impl From<RuntimeString> for String {
+	fn from(string: RuntimeString) -> Self {
+		match string {
+			RuntimeString::Borrowed(data) => data.to_owned(),
+			RuntimeString::Owned(data) => data,
+		}
+	}
+}
+
+impl Default for RuntimeString {
+	fn default() -> Self {
+		Self::Borrowed(Default::default())
+	}
+}
+
+impl PartialEq for RuntimeString {
+	fn eq(&self, other: &Self) -> bool {
+		self.as_ref() == other.as_ref()
+	}
+}
+
+impl AsRef<[u8]> for RuntimeString {
+	fn as_ref(&self) -> &[u8] {
+		match self {
+			Self::Borrowed(val) => val.as_ref(),
+			Self::Owned(val) => val.as_ref(),
+		}
+	}
+}
+
+impl Encode for RuntimeString {
+	fn encode(&self) -> Vec<u8> {
+		match self {
+			Self::Borrowed(val) => val.encode(),
+			Self::Owned(val) => val.encode(),
+		}
+	}
+}
+
+impl Decode for RuntimeString {
+	fn decode<I: codec::Input>(value: &mut I) -> Result<Self, codec::Error> {
+		Decode::decode(value).map(Self::Owned)
+	}
+}
+
+#[cfg(feature = "std")]
+impl std::fmt::Display for RuntimeString {
+	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+		match self {
+			Self::Borrowed(val) => write!(f, "{}", val),
+			Self::Owned(val) => write!(f, "{}", val),
+		}
+	}
+}
+
+#[cfg(feature = "std")]
+impl serde::Serialize for RuntimeString {
+	fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+		match self {
+			Self::Borrowed(val) => val.serialize(serializer),
+			Self::Owned(val) => val.serialize(serializer),
+		}
+	}
+}
+
+#[cfg(feature = "std")]
+impl<'de> serde::Deserialize<'de> for RuntimeString {
+	fn deserialize<D: serde::Deserializer<'de>>(de: D) -> Result<Self, D::Error> {
+		String::deserialize(de).map(Self::Owned)
+	}
+}
+
+/// Create a const [`RuntimeString`].
+#[macro_export]
+macro_rules! create_runtime_str {
+	( $y:expr ) => {{ $crate::RuntimeString::Borrowed($y) }}
+}