Upgradeable validation functions (#918)

* upgrade primitives to allow changing validation function

* set up storage schema for old parachains code

* fix compilation errors

* fix test compilation

* add some tests for past code meta

* most of the runtime logic for code upgrades

* implement old-code pruning

* add a couple tests

* clean up remaining TODOs

* add a whole bunch of tests for runtime functionality

* remove unused function

* fix runtime compilation

* extract some primitives to parachain crate

* add validation-code upgrades to validation params and result

* extend validation params with code upgrade fields

* provide maximums to validation params

* port test-parachains

* add a code-upgrader test-parachain and tests

* fix collator tests

* move test-parachains to own folder to work around compilation errors

* fix test compilation

* update the Cargo.lock

* fix parachains tests

* remove dbg! invocation

* use new pool in code-upgrader

* bump lockfile

* link TODO to issue

polkadot/parachain/test-parachains/tests/lib.rs

@@ -0,0 +1,40 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+mod adder;
+mod code_upgrader;
+mod wasm_executor;
+
+use parachain::{
+	self, primitives::UpwardMessage, wasm_executor::{Externalities, run_worker},
+};
+
+struct DummyExt;
+impl Externalities for DummyExt {
+	fn post_upward_message(&mut self, _: UpwardMessage) -> Result<(), String> {
+		Ok(())
+	}
+}
+
+// This is not an actual test, but rather an entry point for out-of process WASM executor.
+// When executing tests the executor spawns currently executing binary, which happens to be test binary.
+// It then passes "validation_worker" on CLI effectivly making rust test executor to run this single test.
+#[test]
+fn validation_worker() {
+	if let Some(id) = std::env::args().find(|a| a.starts_with("/shmem_rs_")) {
+		run_worker(&id).unwrap()
+	}
+}