ChainSpec extensions (#3692)

* Add some chainspec tests and make sure we validate it.

* Manual implementation of Extension + Forks definitions.

* Move chain spec to separate crate.

* Allow using ChainSpec with extensions.

* Renames.

* Implement Extension derive.

* Implement Extension for Forks.

* Support specifying fork blocks.

* make for_blocks work

* Support forks correctly.

* Add a bunch of docs.

* Make fork blocks optional.

* Add missing docs.

* Fix build.

* Use struct for check_block params.

* Fix tests?

* Clean up.

substrate/core/consensus/common/src/block_import.rs

@@ -90,7 +90,17 @@ pub enum ForkChoiceStrategy {
 	Custom(bool),
 }
 
-/// Data required to import a Block
+/// Data required to check validity of a Block.
+pub struct BlockCheckParams<Block: BlockT> {
+	/// Hash of the block that we verify.
+	pub hash: Block::Hash,
+	/// Block number of the block that we verify.
+	pub number: NumberFor<Block>,
+	/// Parent hash of the block that we verify.
+	pub parent_hash: Block::Hash,
+}
+
+/// Data required to import a Block.
 pub struct BlockImportParams<Block: BlockT> {
 	/// Origin of the Block
 	pub origin: BlockOrigin,
@@ -172,8 +182,7 @@ pub trait BlockImport<B: BlockT> {
 	/// Check block preconditions.
 	fn check_block(
 		&mut self,
-		hash: B::Hash,
-		parent_hash: B::Hash,
+		block: BlockCheckParams<B>,
 	) -> Result<ImportResult, Self::Error>;
 
 	/// Import a block.
@@ -192,10 +201,9 @@ impl<B: BlockT> BlockImport<B> for crate::import_queue::BoxBlockImport<B> {
 	/// Check block preconditions.
 	fn check_block(
 		&mut self,
-		hash: B::Hash,
-		parent_hash: B::Hash,
+		block: BlockCheckParams<B>,
 	) -> Result<ImportResult, Self::Error> {
-		(**self).check_block(hash, parent_hash)
+		(**self).check_block(block)
 	}
 
 	/// Import a block.
@@ -217,10 +225,9 @@ where for<'r> &'r T: BlockImport<B, Error = E>
 
 	fn check_block(
 		&mut self,
-		hash: B::Hash,
-		parent_hash: B::Hash,
+		block: BlockCheckParams<B>,
 	) -> Result<ImportResult, Self::Error> {
-		(&**self).check_block(hash, parent_hash)
+		(&**self).check_block(block)
 	}
 
 	fn import_block(

substrate/core/consensus/common/src/import_queue.rs

@@ -30,7 +30,7 @@ use sr_primitives::{Justification, traits::{Block as BlockT, Header as _, Number
 use crate::error::Error as ConsensusError;
 use crate::block_import::{
 	BlockImport, BlockOrigin, BlockImportParams, ImportedAux, JustificationImport, ImportResult,
-	FinalityProofImport,
+	BlockCheckParams, FinalityProofImport,
 };
 
 pub use basic_queue::BasicQueue;
@@ -194,7 +194,7 @@ pub fn import_single_block<B: BlockT, V: Verifier<B>>(
 
 	let number = header.number().clone();
 	let hash = header.hash();
-	let parent = header.parent_hash().clone();
+	let parent_hash = header.parent_hash().clone();
 
 	let import_error = |e| {
 		match e {
@@ -204,7 +204,7 @@ pub fn import_single_block<B: BlockT, V: Verifier<B>>(
 			},
 			Ok(ImportResult::Imported(aux)) => Ok(BlockImportResult::ImportedUnknown(number, aux, peer.clone())),
 			Ok(ImportResult::UnknownParent) => {
-				debug!(target: "sync", "Block with unknown parent {}: {:?}, parent: {:?}", number, hash, parent);
+				debug!(target: "sync", "Block with unknown parent {}: {:?}, parent: {:?}", number, hash, parent_hash);
 				Err(BlockImportError::UnknownParent)
 			},
 			Ok(ImportResult::KnownBad) => {
@@ -217,8 +217,7 @@ pub fn import_single_block<B: BlockT, V: Verifier<B>>(
 			}
 		}
 	};
-
-	match import_error(import_handle.check_block(hash, parent))? {
+	match import_error(import_handle.check_block(BlockCheckParams { hash, number, parent_hash }))? {
 		BlockImportResult::ImportedUnknown { .. } => (),
 		r => return Ok(r), // Any other successful result means that the block is already imported.
 	}

substrate/core/consensus/common/src/lib.rs

@@ -48,7 +48,7 @@ const MAX_BLOCK_SIZE: usize = 4 * 1024 * 1024 + 512;
 
 pub use self::error::Error;
 pub use block_import::{
-	BlockImport, BlockOrigin, ForkChoiceStrategy, ImportedAux, BlockImportParams, ImportResult,
+	BlockImport, BlockOrigin, ForkChoiceStrategy, ImportedAux, BlockImportParams, BlockCheckParams, ImportResult,
 	JustificationImport, FinalityProofImport,
 };
 pub use select_chain::SelectChain;