Skip modified compilation for namespaces if solc < 0.8.20

packages/core/src/index.ts

@@ -60,3 +60,4 @@ export { ValidateUpgradeSafetyOptions, validateUpgradeSafety, ProjectReport, Ref
 
 export { getUpgradeInterfaceVersion } from './upgrade-interface-version';
 export { makeNamespacedInput } from './utils/make-namespaced';
+export { isNamespaceSupported } from './storage/namespace';

packages/core/src/storage/namespace.ts

@@ -7,6 +7,7 @@ import { getAnnotationArgs, getDocumentation, hasAnnotationTag } from '../utils/
 import { Node } from 'solidity-ast/node';
 import { CompilationContext, getTypeMembers, loadLayoutType } from './extract';
 import { UpgradesError } from '../error';
+import * as versions from 'compare-versions';
 
 /**
  * Loads a contract's namespaces and namespaced type information into the storage layout.
@@ -260,3 +261,7 @@ function findLayoutStructMember(
 function findTypeWithLabel(types: Record<string, TypeItem>, label: string) {
   return Object.values(types).find(type => type.label === label);
 }
+
+export function isNamespaceSupported(solcVersion: string) {
+  return versions.compare(solcVersion, '0.8.20', '>=');
+}

packages/core/src/validate/run.ts

@@ -2,7 +2,6 @@ import { Node } from 'solidity-ast/node';
 import { isNodeType, findAll, ASTDereferencer, astDereferencer } from 'solidity-ast/utils';
 import type { ContractDefinition, FunctionDefinition } from 'solidity-ast';
 import debug from '../utils/debug';
-import * as versions from 'compare-versions';
 
 import { SolcOutput, SolcBytecode, SolcInput } from '../solc-api';
 import { SrcDecoder } from '../src-decoder';
@@ -14,7 +13,7 @@ import { extractStorageLayout } from '../storage/extract';
 import { StorageLayout } from '../storage/layout';
 import { getFullyQualifiedName } from '../utils/contract-name';
 import { getAnnotationArgs as getSupportedAnnotationArgs, getDocumentation } from '../utils/annotations';
-import { getStorageLocationAnnotation } from '../storage/namespace';
+import { getStorageLocationAnnotation, isNamespaceSupported } from '../storage/namespace';
 import { UpgradesError } from '../error';
 
 export type ValidationRunData = Record<string, ContractValidation>;
@@ -243,7 +242,7 @@ function checkNamespaceSolidityVersion(source: string, solcVersion?: string, sol
           () =>
             `Structs with the @custom:storage-location annotation can only be used with Solidity version 0.8.20 or higher. Pass the solcVersion parameter to the validate function, or remove the annotation if the struct is not used for namespaced storage.`,
         );
-      } else if (versions.compare(solcVersion, '0.8.20', '<')) {
+      } else if (!isNamespaceSupported(solcVersion)) {
         throw new UpgradesError(
           `${source}: Namespace annotations require Solidity version >= 0.8.20, but ${solcVersion} was used`,
           () =>

packages/plugin-hardhat/contracts/MakeNamespaced0516.sol

@@ -0,0 +1,12 @@
+pragma solidity ^0.5.16;
+
+/**
+ * @dev foo
+ */
+contract MakeNamespaced0516 {
+    /**
+     * @dev bar
+     */
+    function bar() public view {
+    }
+}

packages/plugin-hardhat/src/index.ts

@@ -97,7 +97,7 @@ subtask(TASK_COMPILE_SOLIDITY, async (args: { force: boolean }, hre, runSuper) =
 });
 
 subtask(TASK_COMPILE_SOLIDITY_COMPILE, async (args: RunCompilerArgs, hre, runSuper) => {
-  const { validate, solcInputOutputDecoder, makeNamespacedInput } = await import('@openzeppelin/upgrades-core');
+  const { isNamespaceSupported, validate, solcInputOutputDecoder, makeNamespacedInput } = await import('@openzeppelin/upgrades-core');
   const { writeValidations } = await import('./utils/validations');
 
   // TODO: patch input
@@ -107,9 +107,12 @@ subtask(TASK_COMPILE_SOLIDITY_COMPILE, async (args: RunCompilerArgs, hre, runSup
   if (isFullSolcOutput(output)) {
     const decodeSrc = solcInputOutputDecoder(args.input, output);
 
-    const namespacedInput = makeNamespacedInput(args.input, output);
-    const { output: namespacedOutput } = await runSuper({ ...args, quiet: true, input: namespacedInput });
-    await checkNamespacedCompileErrors(namespacedOutput);
+    let namespacedOutput = undefined;
+    if (isNamespaceSupported(args.solcVersion)) {
+      const namespacedInput = makeNamespacedInput(args.input, output);
+      namespacedOutput = (await runSuper({ ...args, quiet: true, input: namespacedInput })).output;
+      await checkNamespacedCompileErrors(namespacedOutput);
+    }
 
     const validations = validate(output, decodeSrc, args.solcVersion, args.input, namespacedOutput);
     await writeValidations(hre, validations);

packages/plugin-hardhat/test/namespaced.js

@@ -28,6 +28,7 @@ test.before(async t => {
   t.context.InheritsNamespaceV2_BadAndHasLayout = await ethers.getContractFactory(
     'InheritsNamespaceV2_BadAndHasLayout',
   );
+  t.context.MakeNamespaced0516 = await ethers.getContractFactory('MakeNamespaced0516');
 });
 
 test('validate namespace - ok', async t => {
@@ -231,3 +232,9 @@ test('moving namespace to inherited contract - delete variable and has layout -
   const error = await t.throwsAsync(() => upgrades.validateUpgrade(Example, InheritsNamespaceV2_BadAndHasLayout));
   t.snapshot(error.message);
 });
+
+test('validate 0.5.16 contract without namespaces - ok', async t => {
+  const { MakeNamespaced0516 } = t.context;
+
+  await upgrades.validateImplementation(MakeNamespaced0516);
+});