Set default evmVersion to paris for solc gte 0.8.20

.changeset/sharp-rabbits-tell.md

@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Set the default evmVersion to paris for solc versions that are greater than or equal than 0.8.20.

docs/src/content/hardhat-runner/docs/config/index.md

@@ -208,3 +208,20 @@ You can configure how your tests are run using the `mocha` entry, which accepts
 ## Quickly integrating other tools from Hardhat's config
 
 Hardhat's config file will always run before any task, so you can use it to integrate with other tools, like importing `@babel/register`.
+
+## Default EVM Version
+
+The default EVM version is determined by solc's choice for a given compiler version. To specify a different EVM version, modify your `hardhat.config.js`:
+
+```js
+module.exports = {
+  solidity: {
+    version: "0.8.21",
+    settings: {
+      evmVersion: "shanghai",
+    },
+  },
+};
+```
+
+Since `0.8.20`, solc's EVM default is `shanghai`, leading to an issue with the `PUSH0` opcode on L2 chains. To address this, post `0.8.20`, Hardhat defaults to `paris`. This value can be overriden by using the above configuration.

packages/hardhat-core/src/internal/core/config/config-resolution.ts

@@ -1,5 +1,6 @@
 import cloneDeep from "lodash/cloneDeep";
 import path from "path";
+import semver from "semver";
 
 import {
   HardhatConfig,
@@ -385,6 +386,10 @@ function resolveCompiler(compiler: SolcUserConfig): SolcConfig {
     settings: compiler.settings ?? {},
   };
 
+  if (semver.gte(resolved.version, "0.8.20")) {
+    resolved.settings.evmVersion = compiler.settings?.evmVersion ?? "paris";
+  }
+
   resolved.settings.optimizer = {
     enabled: false,
     runs: 200,

packages/hardhat-core/test/fixture-projects/project-0.8.20-override-evm-version/.gitignore

@@ -0,0 +1,2 @@
+artifacts/
+cache/

packages/hardhat-core/test/fixture-projects/project-0.8.20-override-evm-version/contracts/Lock.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity 0.8.20;
+
+// Uncomment this line to use console.log
+// import "hardhat/console.sol";
+
+contract Lock {
+  uint public unlockTime;
+  address payable public owner;
+
+  event Withdrawal(uint amount, uint when);
+
+  constructor(uint _unlockTime) payable {
+    require(
+      block.timestamp < _unlockTime,
+      "Unlock time should be in the future"
+    );
+
+    unlockTime = _unlockTime;
+    owner = payable(msg.sender);
+  }
+
+  function withdraw() public {
+    // Uncomment this line, and the import of "hardhat/console.sol", to print a log in your terminal
+    // console.log("Unlock time is %o and block timestamp is %o", unlockTime, block.timestamp);
+
+    require(block.timestamp >= unlockTime, "You can't withdraw yet");
+    require(msg.sender == owner, "You aren't the owner");
+
+    emit Withdrawal(address(this).balance, block.timestamp);
+
+    owner.transfer(address(this).balance);
+  }
+}

packages/hardhat-core/test/fixture-projects/project-0.8.20-override-evm-version/hardhat.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+  solidity: {
+    compilers: [{ version: "0.8.20", settings: { evmVersion: "shanghai" } }],
+  },
+};

packages/hardhat-core/test/fixture-projects/project-0.8.20/.gitignore

@@ -0,0 +1,2 @@
+artifacts/
+cache/

packages/hardhat-core/test/fixture-projects/project-0.8.20/contracts/Lock.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity 0.8.20;
+
+// Uncomment this line to use console.log
+// import "hardhat/console.sol";
+
+contract Lock {
+  uint public unlockTime;
+  address payable public owner;
+
+  event Withdrawal(uint amount, uint when);
+
+  constructor(uint _unlockTime) payable {
+    require(
+      block.timestamp < _unlockTime,
+      "Unlock time should be in the future"
+    );
+
+    unlockTime = _unlockTime;
+    owner = payable(msg.sender);
+  }
+
+  function withdraw() public {
+    // Uncomment this line, and the import of "hardhat/console.sol", to print a log in your terminal
+    // console.log("Unlock time is %o and block timestamp is %o", unlockTime, block.timestamp);
+
+    require(block.timestamp >= unlockTime, "You can't withdraw yet");
+    require(msg.sender == owner, "You aren't the owner");
+
+    emit Withdrawal(address(this).balance, block.timestamp);
+
+    owner.transfer(address(this).balance);
+  }
+}

packages/hardhat-core/test/fixture-projects/project-0.8.20/hardhat.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+  solidity: "0.8.20",
+};

packages/hardhat-core/test/internal/core/config/config-resolution.ts

@@ -24,6 +24,18 @@ import {
   HttpNetworkUserConfig,
 } from "../../../../src/types";
 import { HardforkName } from "../../../../src/internal/util/hardforks";
+import { useFixtureProject } from "../../../helpers/project";
+import {
+  getAllFilesMatchingSync,
+  getRealPathSync,
+} from "../../../../src/internal/util/fs-utils";
+import { useEnvironment } from "../../../helpers/environment";
+
+function getBuildInfos() {
+  return getAllFilesMatchingSync(getRealPathSync("artifacts/build-info"), (f) =>
+    f.endsWith(".json")
+  );
+}
 
 describe("Config resolution", () => {
   describe("Default config merging", () => {
@@ -857,4 +869,119 @@ describe("Config resolution", () => {
       });
     });
   });
+
+  describe("evmVersion default", function () {
+    it("Should default to paris if solc is gte 0.8.20", () => {
+      let config = resolveConfig(__filename, {
+        solidity: "0.8.20",
+      });
+      assert.equal(config.solidity.compilers[0]?.settings?.evmVersion, "paris");
+
+      config = resolveConfig(__filename, {
+        solidity: "0.8.21",
+      });
+      assert.equal(config.solidity.compilers[0]?.settings?.evmVersion, "paris");
+
+      config = resolveConfig(__filename, {
+        solidity: {
+          compilers: [{ version: "0.8.20" }],
+          overrides: {
+            "contracts/ERC20.sol": {
+              version: "0.8.21",
+            },
+          },
+        },
+      });
+      assert.equal(config.solidity.compilers[0]?.settings?.evmVersion, "paris");
+      assert.equal(
+        config.solidity.overrides["contracts/ERC20.sol"]?.settings?.evmVersion,
+        "paris"
+      );
+    });
+
+    it("Should use the solc default if solc is lt 0.8.20", () => {
+      let config = resolveConfig(__filename, {
+        solidity: "0.8.19",
+      });
+      assert.isUndefined(config.solidity.compilers[0]?.settings?.evmVersion);
+
+      config = resolveConfig(__filename, {
+        solidity: {
+          compilers: [{ version: "0.5.7" }],
+          overrides: {
+            "contracts/ERC20.sol": {
+              version: "0.7.6",
+            },
+          },
+        },
+      });
+      assert.isUndefined(config.solidity.compilers[0]?.settings?.evmVersion);
+      assert.isUndefined(
+        config.solidity.overrides["contracts/ERC20.sol"]?.settings?.evmVersion
+      );
+    });
+
+    it("Should let the user override the evmVersion", () => {
+      const config = resolveConfig(__filename, {
+        solidity: {
+          compilers: [
+            { version: "0.8.20", settings: { evmVersion: "istanbul" } },
+          ],
+          overrides: {
+            "contracts/ERC20.sol": {
+              version: "0.8.21",
+              settings: { evmVersion: "shanghai" },
+            },
+          },
+        },
+      });
+
+      assert.equal(
+        config.solidity.compilers[0]?.settings?.evmVersion,
+        "istanbul"
+      );
+      assert.equal(
+        config.solidity.overrides["contracts/ERC20.sol"]?.settings?.evmVersion,
+        "shanghai"
+      );
+    });
+
+    describe("With a solc 0.8.20 project and default config", () => {
+      useFixtureProject("project-0.8.20");
+      useEnvironment();
+
+      it("Should not emit PUSH0 opcodes when compiling a contract with solc gte 0.8.20 and default config", async function () {
+        await this.env.run("compile");
+        const source = "contracts/Lock.sol";
+        const contract = "Lock";
+
+        const [buildInfo] = getBuildInfos();
+        const { output } = require(buildInfo);
+
+        assert.notInclude(
+          output.contracts[source][contract].evm.bytecode.opcodes,
+          "PUSH0"
+        );
+      });
+    });
+
+    describe("With a solc 0.8.20 project and overriden config", () => {
+      useFixtureProject("project-0.8.20-override-evm-version");
+      useEnvironment();
+
+      it("Should emit PUSH0 opcodes when compiling a contract with solc gte 0.8.20 and overriden config", async function () {
+        await this.env.run("compile");
+        const source = "contracts/Lock.sol";
+        const contract = "Lock";
+
+        const [buildInfo] = getBuildInfos();
+        const { output } = require(buildInfo);
+
+        assert.include(
+          output.contracts[source][contract].evm.bytecode.opcodes,
+          "PUSH0"
+        );
+      });
+    });
+  });
 });