implement the coinbase opcode (#179)

Signed-off-by: xermicus <cyrill@parity.io>

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 ## Unreleased
 
+This is a development pre-release.
+
+### Added
+- Support for the `coinbase` opcode.
+
+### Changed 
+
+### Fixed
+
 ## v0.1.0-dev.9
 
 This is a development pre-release.

Cargo.toml

@@ -73,7 +73,7 @@ assert_fs = "1.1.2"
 # polkadot-sdk and friends
 codec = { version = "3.6.12", default-features = false, package = "parity-scale-codec" }
 scale-info = { version = "2.11.6", default-features = false }
-polkadot-sdk = { git = "https://github.com/paritytech/polkadot-sdk", rev = "4302f74f7874e6a894578731142a7b310a1449b0" }
+polkadot-sdk = { git = "https://github.com/paritytech/polkadot-sdk", rev = "2d53238a186ac1161ca9998471694eb1833efb1d" }
 
 # llvm
 [workspace.dependencies.inkwell]

crates/differential/genesis.json

@@ -18,7 +18,7 @@
         "terminalTotalDifficulty": 0,
         "terminalTotalDifficultyPassed": true
     },
-    "coinbase": "0x0000000000000000000000000000000000000000",
+    "coinbase": "0xffffffffffffffffffffffffffffffffffffffff",
     "difficulty": "0x20000",
     "extraData": "",
     "gasLimit": "0xffffffff",

crates/integration/contracts/Coinbase.sol

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8;
+
+/* runner.json
+{
+    "differential": true,
+    "actions": [
+        {
+            "Instantiate": {
+                "code": {
+                    "Solidity": {
+                        "contract": "Coinbase"
+                    }
+                }
+            }
+        }
+    ]
+}
+*/
+
+contract Coinbase {
+    constructor() payable {
+        address coinbase = address(0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF);
+        assert(block.coinbase == coinbase);
+    }
+}

crates/integration/src/tests.rs

@@ -50,6 +50,7 @@ test_spec!(gas_price, "GasPrice", "GasPrice.sol");
 test_spec!(gas_left, "GasLeft", "GasLeft.sol");
 test_spec!(gas_limit, "GasLimit", "GasLimit.sol");
 test_spec!(base_fee, "BaseFee", "BaseFee.sol");
+test_spec!(coinbase, "Coinbase", "Coinbase.sol");
 
 fn instantiate(path: &str, contract: &str) -> Vec<SpecsAction> {
     vec![Instantiate {

crates/llvm-context/src/polkavm/evm/context.rs

@@ -122,12 +122,20 @@ where
 
 /// Translates the `coinbase` instruction.
 pub fn coinbase<'ctx, D>(
-    _context: &mut Context<'ctx, D>,
+    context: &mut Context<'ctx, D>,
 ) -> anyhow::Result<inkwell::values::BasicValueEnum<'ctx>>
 where
     D: Dependency + Clone,
 {
-    todo!()
+    let pointer = context.build_alloca_at_entry(
+        context.integer_type(revive_common::BIT_LENGTH_ETH_ADDRESS),
+        "coinbase_output",
+    );
+    context.build_runtime_call(
+        revive_runtime_api::polkavm_imports::BLOCK_AUTHOR,
+        &[pointer.to_int(context).into()],
+    );
+    context.build_load_address(pointer)
 }
 
 /// Translates the `basefee` instruction.

crates/runner/src/runtime.rs

@@ -1,5 +1,4 @@
-use frame_support::{runtime, weights::constants::WEIGHT_REF_TIME_PER_SECOND};
-
+use frame_support::{runtime, traits::FindAuthor, weights::constants::WEIGHT_REF_TIME_PER_SECOND};
 use pallet_revive::AccountId32Mapper;
 use polkadot_sdk::*;
 use polkadot_sdk::{
@@ -11,8 +10,6 @@ pub type Balance = u128;
 pub type AccountId = pallet_revive::AccountId32Mapper<Runtime>;
 pub type Block = frame_system::mocking::MockBlock<Runtime>;
 pub type Hash = <Runtime as frame_system::Config>::Hash;
-pub type EventRecord =
-    frame_system::EventRecord<<Runtime as frame_system::Config>::RuntimeEvent, Hash>;
 
 #[runtime]
 mod runtime {
@@ -26,7 +23,8 @@ mod runtime {
         RuntimeHoldReason,
         RuntimeSlashReason,
         RuntimeLockId,
-        RuntimeTask
+        RuntimeTask,
+        RuntimeViewFunction
     )]
     pub struct Runtime;
 
@@ -88,4 +86,14 @@ impl pallet_revive::Config for Runtime {
     type InstantiateOrigin = EnsureSigned<AccountId32>;
     type CodeHashLockupDepositPercent = CodeHashLockupDepositPercent;
     type ChainId = ConstU64<420_420_420>;
+    type FindAuthor = Self;
+}
+
+impl FindAuthor<<Runtime as frame_system::Config>::AccountId> for Runtime {
+    fn find_author<'a, I>(_digests: I) -> Option<<Runtime as frame_system::Config>::AccountId>
+    where
+        I: 'a + IntoIterator<Item = (frame_support::ConsensusEngineId, &'a [u8])>,
+    {
+        Some([0xff; 32].into())
+    }
 }

crates/runtime-api/src/polkavm_imports.c

@@ -72,6 +72,8 @@ POLKAVM_IMPORT(void, balance_of, uint32_t, uint32_t)
 
 POLKAVM_IMPORT(void, base_fee, uint32_t)
 
+POLKAVM_IMPORT(void, block_author, uint32_t)
+
 POLKAVM_IMPORT(void, block_hash, uint32_t, uint32_t)
 
 POLKAVM_IMPORT(void, block_number, uint32_t)

crates/runtime-api/src/polkavm_imports.rs

@@ -22,6 +22,8 @@ pub static BALANCE_OF: &str = "balance_of";
 
 pub static BASE_FEE: &str = "base_fee";
 
+pub static BLOCK_AUTHOR: &str = "block_author";
+
 pub static BLOCK_HASH: &str = "block_hash";
 
 pub static BLOCK_NUMBER: &str = "block_number";
@@ -80,13 +82,14 @@ pub static WEIGHT_TO_FEE: &str = "weight_to_fee";
 
 /// All imported runtime API symbols.
 /// Useful for configuring common attributes and linkage.
-pub static IMPORTS: [&str; 34] = [
+pub static IMPORTS: [&str; 35] = [
     SBRK,
     MEMORY_SIZE,
     ADDRESS,
     BALANCE,
     BALANCE_OF,
     BASE_FEE,
+    BLOCK_AUTHOR,
     BLOCK_HASH,
     BLOCK_NUMBER,
     CALL,