Files
pezkuwi-subxt/substrate/frame/system
Sergei Shulepov 0849bcce0e Embed runtime version as a custom section (#8688)
* emit a custom section from impl_runtime_apis!

This change emits a custom section from the impl_runtime_apis! proc macro.

Each implemented API will result to emitting a link section `runtime_apis`.
During linking all sections with this name will be concatenated and
placed into the final wasm binary under the same name.

* Introduce `runtime_version` proc macro

This macro takes an existing `RuntimeVersion` const declaration, parses
it and emits the version information in form of a linking section.
Ultimately such a linking section will result into a custom wasm
section.

* Parse custom wasm section for runtime version

* Apply suggestions from code review

Co-authored-by: David <dvdplm@gmail.com>

* Fix sc-executor integration tests

* Nits

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Refactor apis section deserialization

* Fix version decoding

* Reuse uncompressed value for CallInWasm

* Log on decompression error

* Simplify if

* Reexport proc-macro from sp_version

* Merge ReadRuntimeVersionExt

* Export `read_embedded_version`

* Fix test

* Simplify searching for custom section

Co-authored-by: David <dvdplm@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
2021-05-12 13:39:08 +00:00
..
2021-02-10 19:23:18 +01:00

System Module

The System module provides low-level access to core types and cross-cutting utilities. It acts as the base layer for other pallets to interact with the Substrate framework components.

Overview

The System module defines the core data types used in a Substrate runtime. It also provides several utility functions (see Module) for other FRAME pallets.

In addition, it manages the storage items for extrinsics data, indexes, event records, and digest items, among other things that support the execution of the current block.

It also handles low-level tasks like depositing logs, basic set up and take down of temporary storage entries, and access to previous block hashes.

Interface

Dispatchable Functions

The System module does not implement any dispatchable functions.

Public Functions

See the Module struct for details of publicly available functions.

Signed Extensions

The System module defines the following extensions:

  • [CheckWeight]: Checks the weight and length of the block and ensure that it does not exceed the limits.
  • [CheckNonce]: Checks the nonce of the transaction. Contains a single payload of type T::Index.
  • [CheckEra]: Checks the era of the transaction. Contains a single payload of type Era.
  • [CheckGenesis]: Checks the provided genesis hash of the transaction. Must be a part of the signed payload of the transaction.
  • [CheckSpecVersion]: Checks that the runtime version is the same as the one used to sign the transaction.
  • [CheckTxVersion]: Checks that the transaction version is the same as the one used to sign the transaction.

Lookup the runtime aggregator file (e.g. node/runtime) to see the full list of signed extensions included in a chain.

Usage

Prerequisites

Import the System module and derive your module's configuration trait from the system trait.

Example - Get extrinsic count and parent hash for the current block

use frame_support::{decl_module, dispatch};
use frame_system::{self as system, ensure_signed};

pub trait Config: system::Config {}

decl_module! {
	pub struct Module<T: Config> for enum Call where origin: T::Origin {
		#[weight = 0]
		pub fn system_module_example(origin) -> dispatch::DispatchResult {
			let _sender = ensure_signed(origin)?;
			let _extrinsic_count = <system::Pallet<T>>::extrinsic_count();
			let _parent_hash = <system::Pallet<T>>::parent_hash();
			Ok(())
		}
	}
}

License: Apache-2.0