Collator for the "adder" (formerly basic-add) parachain and various small fixes (#438)

* update basic_add wasm

* wasm feature and collator feature

* move test parachains around a little

* fix wasm build for basic_add

* move basic_add to adder, introduce README

* minimal basic_add collator

* ensure collator messages are sent in the right order

* more logging

* route consensus statements to all peers

* minor bugfixes for parachains

* genesis builder accounts for parachain heads

* fix parachains tests

* targets for txpool

* tweak runtime + collator

* fix version in adder-collator

* consistency for overflowing

* adjust comment

* fix stable test run

* remove dummy registration test

* final grumbles

polkadot/test-parachains/adder/wasm/src/lib.rs

@@ -0,0 +1,73 @@
+// Copyright 2017 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/>.
+
+//! WASM validation for adder parachain.
+
+#![no_std]
+
+#![feature(
+	alloc, core_intrinsics, lang_items, panic_implementation, core_panic_info,
+	alloc_error_handler
+)]
+
+extern crate alloc;
+extern crate wee_alloc;
+extern crate pwasm_libc;
+extern crate adder;
+extern crate polkadot_parachain as parachain;
+extern crate tiny_keccak;
+
+// Define global allocator.
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+use core::{intrinsics, panic};
+use parachain::ValidationResult;
+use parachain::codec::{Encode, Decode};
+use adder::{HeadData, BlockData};
+
+#[panic_implementation]
+#[no_mangle]
+pub fn panic(_info: &panic::PanicInfo) -> ! {
+	unsafe {
+		intrinsics::abort()
+	}
+}
+
+#[alloc_error_handler]
+#[no_mangle]
+pub fn oom(_: ::core::alloc::Layout) -> ! {
+	unsafe {
+		intrinsics::abort();
+	}
+}
+
+#[no_mangle]
+pub extern fn validate(offset: usize, len: usize) -> usize {
+	let params = unsafe { ::parachain::load_params(offset, len) };
+	let parent_head = HeadData::decode(&mut &params.parent_head[..])
+		.expect("invalid parent head format.");
+
+	let block_data = BlockData::decode(&mut &params.block_data[..])
+		.expect("invalid block data format.");
+
+	let parent_hash = ::tiny_keccak::keccak256(&params.parent_head[..]);
+
+	match ::adder::execute(parent_hash, parent_head, &block_data) {
+		Ok(new_head) => parachain::write_result(ValidationResult { head_data: new_head.encode() }),
+		Err(_) => panic!("execution failure"),
+	}
+}