the basefee opcode (#142)

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

crates/integration/contracts/BaseFee.sol

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8;
+
+/* runner.json
+{
+    "differential": false,
+    "actions": [
+        {
+            "Instantiate": {
+                "code": {
+                    "Solidity": {
+                        "contract": "BaseFee"
+                    }
+                }
+            }
+        },
+        {
+            "VerifyCall": {
+                "success": true
+            }
+        }
+    ]
+}
+*/
+
+contract BaseFee {
+    constructor() payable {
+        assert(block.basefee == 0);
+    }
+}

crates/integration/src/tests.rs

@@ -49,6 +49,7 @@ test_spec!(delegate, "Delegate", "Delegate.sol");
 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");
 
 fn instantiate(path: &str, contract: &str) -> Vec<SpecsAction> {
     vec![Instantiate {

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

@@ -137,7 +137,7 @@ pub fn basefee<'ctx, D>(
 where
     D: Dependency + Clone,
 {
-    Ok(context.word_const(0).as_basic_value_enum())
+    context.build_runtime_call_to_getter(revive_runtime_api::polkavm_imports::BASE_FEE)
 }
 
 /// Translates the `address` instruction.

crates/runtime-api/src/polkavm_imports.c

@@ -70,6 +70,8 @@ POLKAVM_IMPORT(void, balance, uint32_t)
 
 POLKAVM_IMPORT(void, balance_of, uint32_t, uint32_t)
 
+POLKAVM_IMPORT(void, base_fee, 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

@@ -20,6 +20,8 @@ pub static BALANCE: &str = "balance";
 
 pub static BALANCE_OF: &str = "balance_of";
 
+pub static BASE_FEE: &str = "base_fee";
+
 pub static BLOCK_HASH: &str = "block_hash";
 
 pub static BLOCK_NUMBER: &str = "block_number";
@@ -78,12 +80,13 @@ 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; 33] = [
+pub static IMPORTS: [&str; 34] = [
     SBRK,
     MEMORY_SIZE,
     ADDRESS,
     BALANCE,
     BALANCE_OF,
+    BASE_FEE,
     BLOCK_HASH,
     BLOCK_NUMBER,
     CALL,