fix: allow stateless constructors in validation

.changeset/stateless-constructor-validation.md

@@ -0,0 +1,5 @@
+---
+'@openzeppelin/upgrades-core': patch
+---
+
+Allow contracts annotated with `@custom:stateless` to define constructor logic during upgrade safety validation.

packages/core/contracts/test/ValidationsNatspec.sol

@@ -26,10 +26,20 @@ contract HasNonEmptyConstructorNatspec4 {
   constructor() { msg.sender; }
 }
 
+/// @custom:stateless
+contract StatelessNonEmptyConstructor {
+  constructor() {
+    assembly {
+      sstore(0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00, 1)
+    }
+  }
+}
+
 contract ParentHasNonEmptyConstructorNatspec1 is HasNonEmptyConstructorNatspec1 {}
 contract ParentHasNonEmptyConstructorNatspec2 is HasNonEmptyConstructorNatspec2 {}
 contract AncestorHasNonEmptyConstructorNatspec1 is ParentHasNonEmptyConstructorNatspec1 {}
 contract AncestorHasNonEmptyConstructorNatspec2 is ParentHasNonEmptyConstructorNatspec2 {}
+contract ChildOfStatelessNonEmptyConstructor is StatelessNonEmptyConstructor {}
 
 /// @custom:oz-upgrades-unsafe-allow state-variable-assignment
 contract HasStateVariableAssignmentNatspec1 {

packages/core/contracts/test/cli/Validate.sol

@@ -36,6 +36,22 @@ contract HasUpgradeToConstructorUnsafe {
   }
 }
 
+/**
+ * @custom:stateless
+ */
+contract StatelessConstructor {
+  constructor() {
+    assembly {
+      sstore(0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00, 1)
+    }
+  }
+}
+
+contract HasStatelessConstructorParent is StatelessConstructor {
+  function upgradeTo(address) public {
+  }
+}
+
 /**
  * @custom:oz-upgrades
  */
@@ -151,4 +167,4 @@ contract StorageV2_Ok_NoAnnotation {
   uint256 public x;
   uint256 public y;
   uint256[48] private __gap;
-}
+}

packages/core/src/cli/cli.test.ts

@@ -290,6 +290,15 @@ test('validate - single contract - ok', async t => {
   t.snapshot(output);
 });
 
+test('validate - single contract with stateless constructor parent - ok', async t => {
+  const temp = await getTempDir(t);
+  const buildInfo = await artifacts.getBuildInfo(`contracts/test/cli/Validate.sol:HasStatelessConstructorParent`);
+  await fs.writeFile(path.join(temp, 'validate.json'), JSON.stringify(buildInfo));
+
+  const output = (await execAsync(`${CLI} validate ${temp} --contract HasStatelessConstructorParent`)).stdout;
+  t.regex(output, /SUCCESS/);
+});
+
 test('validate - fully qualified version of ambiguous contract name', async t => {
   const temp = await getTempDir(t);
   const buildInfo = await artifacts.getBuildInfo(`contracts/test/ValidationsSameNameSafe.sol:SameName`);

packages/core/src/validate.test.ts

@@ -22,6 +22,7 @@ test.before(async t => {
   const contracts = [
     'contracts/test/Validations.sol:HasEmptyConstructor',
     'contracts/test/ValidationsNatspec.sol:HasNonEmptyConstructorNatspec1',
+    'contracts/test/ValidationsNatspec.sol:ChildOfStatelessNonEmptyConstructor',
     'contracts/test/Proxiable.sol:ChildOfProxiable',
     'contracts/test/ValidationsUDVT.sol:ValidationsUDVT',
     'contracts/test/ValidationsFunctionPointers.sol:InternalFunctionPointer',
@@ -128,6 +129,7 @@ testValid('ParentHasNonEmptyConstructorNatspec1', 'transparent', true);
 testValid('ParentHasNonEmptyConstructorNatspec2', 'transparent', true);
 testValid('AncestorHasNonEmptyConstructorNatspec1', 'transparent', true);
 testValid('AncestorHasNonEmptyConstructorNatspec2', 'transparent', true);
+testValid('ChildOfStatelessNonEmptyConstructor', 'transparent', true);
 testValid('HasStateVariableAssignmentNatspec1', 'transparent', true);
 testValid('HasStateVariableAssignmentNatspec2', 'transparent', true);
 testValid('HasStateVariableAssignmentNatspec3', 'transparent', false);

packages/core/src/validate/run.ts

@@ -19,7 +19,11 @@ import { extractLinkReferences, LinkReference } from '../link-refs';
 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 {
+  getAnnotationArgs as getSupportedAnnotationArgs,
+  getDocumentation,
+  hasAnnotationTag,
+} from '../utils/annotations';
 import { getStorageLocationAnnotation, isNamespaceSupported } from '../storage/namespace';
 import { UpgradesError } from '../error';
 import { assertUnreachable } from '../utils/assert';
@@ -369,6 +373,10 @@ function getNamespacedCompilationContext(
 }
 
 function* getConstructorErrors(contractDef: ContractDefinition, decodeSrc: SrcDecoder): Generator<ValidationError> {
+  if (hasAnnotationTag(getDocumentation(contractDef), 'stateless')) {
+    return;
+  }
+
   for (const fnDef of findAll('FunctionDefinition', contractDef, node => skipCheck('constructor', node))) {
     if (fnDef.kind === 'constructor' && ((fnDef.body?.statements?.length ?? 0) > 0 || fnDef.modifiers.length > 0)) {
       yield {