add annotation validation to validate API

Author: neetopia

api/src/main/kotlin/com/google/devtools/ksp/utils.kt

@@ -83,8 +83,8 @@ fun KSDeclaration.isLocal(): Boolean {
  * Perform a validation on a given symbol to check if all interested types in symbols enclosed scope are valid, i.e. resolvable.
  * @param predicate: A lambda for filtering interested symbols for performance purpose. Default checks all.
  */
-fun KSNode.validate(predicate: (KSNode, KSNode) -> Boolean = { _, _-> true } ): Boolean {
-    return this.accept(KSValidateVisitor(predicate), Unit)
+fun KSNode.validate(predicate: (KSNode?, KSNode) -> Boolean = { _, _-> true } ): Boolean {
+    return this.accept(KSValidateVisitor(predicate), null)
 }
 
 /**

api/src/main/kotlin/com/google/devtools/ksp/visitor/KSValidateVisitor.kt

@@ -2,77 +2,69 @@ package com.google.devtools.ksp.visitor
 
 import com.google.devtools.ksp.symbol.*
 
-class KSValidateVisitor(private val predicate: (KSNode, KSNode) -> Boolean) : KSDefaultVisitor<Unit, Boolean>() {
-    private fun validateDeclarations(declarationContainer: KSDeclarationContainer): Boolean {
-        return !declarationContainer.declarations.any { predicate(declarationContainer, it) && !it.accept(this, Unit) }
+class KSValidateVisitor(private val predicate: (KSNode?, KSNode) -> Boolean) : KSDefaultVisitor<KSNode?, Boolean>() {
+    private fun validateType(type: KSType): Boolean {
+        return !type.isError && !type.arguments.any { it.type?.accept(this, null) == false }
     }
 
-    private fun validateTypeParameters(declaration: KSDeclaration): Boolean {
-        return !declaration.typeParameters.any { predicate(declaration, it) && !it.accept(this, Unit) }
+    override fun defaultHandler(node: KSNode, data: KSNode?): Boolean {
+        throw IllegalStateException("unhandled validation condition, please file a bug at https://github.com/google/ksp/issues/new")
     }
 
-    private fun validateType(type: KSType): Boolean {
-        return !type.isError && !type.arguments.any { it.type?.accept(this, Unit) == false }
+    override fun visitDeclaration(declaration: KSDeclaration, data: KSNode?): Boolean {
+        if (!predicate(data, declaration)) {
+            return true
+        }
+        if (!declaration.typeParameters.any { it.accept(this, declaration) }) {
+            return false
+        }
+        return super.visitDeclaration(declaration, data)
     }
 
-    override fun defaultHandler(node: KSNode, data: Unit): Boolean {
-        throw IllegalStateException("unhandled validation condition, please file a bug at https://github.com/google/ksp/issues/new")
+    override fun visitDeclarationContainer(declarationContainer: KSDeclarationContainer, data: KSNode?): Boolean {
+        return !predicate(data, declarationContainer) || declarationContainer.declarations.all { it.accept(this, declarationContainer) }
     }
 
-    override fun visitTypeReference(typeReference: KSTypeReference, data: Unit): Boolean {
+    override fun visitTypeParameter(typeParameter: KSTypeParameter, data: KSNode?): Boolean {
+        return !predicate(data, typeParameter) || typeParameter.bounds.all{ it.accept(this, typeParameter) }
+    }
+
+    override fun visitAnnotation(annotation: KSAnnotation, data: KSNode?): Boolean {
+        return !predicate(data, annotation) || annotation.annotationType.accept(this, annotation)
+    }
+
+    override fun visitTypeReference(typeReference: KSTypeReference, data: KSNode?): Boolean {
         return validateType(typeReference.resolve())
     }
 
-    override fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: Unit): Boolean {
-        if (!validateTypeParameters(classDeclaration)) {
-            return false
-        }
+    override fun visitClassDeclaration(classDeclaration: KSClassDeclaration, data: KSNode?): Boolean {
         if (classDeclaration.asStarProjectedType().isError) {
             return false
         }
-        if (classDeclaration.superTypes.any { predicate(classDeclaration, it) && !it.accept(this, Unit) }) {
+        if (!classDeclaration.superTypes.all{ it.accept(this, classDeclaration) }) {
             return false
         }
-        if (!validateDeclarations(classDeclaration)) {
-            return false
-        }
-        return true
+        return super.visitClassDeclaration(classDeclaration, data)
     }
 
-    override fun visitFunctionDeclaration(function: KSFunctionDeclaration, data: Unit): Boolean {
+    override fun visitFunctionDeclaration(function: KSFunctionDeclaration, data: KSNode?): Boolean {
         if (function.returnType != null && !(predicate(function, function.returnType!!) && function.returnType!!.accept(this, data))) {
             return false
         }
-        if (function.parameters.any { predicate(function, it) && !it.accept(this, Unit)}) {
-            return false
-        }
-        if (!validateTypeParameters(function)) {
-            return false
-        }
-        if (!validateDeclarations(function)) {
+        if (!function.parameters.all{ it.accept(this, function) }) {
             return false
         }
-        return true
+        return super.visitFunctionDeclaration(function, data)
     }
 
-    override fun visitPropertyDeclaration(property: KSPropertyDeclaration, data: Unit): Boolean {
+    override fun visitPropertyDeclaration(property: KSPropertyDeclaration, data: KSNode?): Boolean {
         if (predicate(property, property.type) && property.type.resolve().isError) {
             return false
         }
-        if (!validateTypeParameters(property)) {
-            return false
-        }
-        return true
-    }
-
-    override fun visitTypeParameter(typeParameter: KSTypeParameter, data: Unit): Boolean {
-        if (typeParameter.bounds.any { predicate(typeParameter, it) && !it.accept(this, Unit) }) {
-            return false
-        }
-        return true
+        return super.visitPropertyDeclaration(property, data)
     }
 
-    override fun visitValueParameter(valueParameter: KSValueParameter, data: Unit): Boolean {
-        return valueParameter.type?.accept(this, Unit) != false
+    override fun visitValueParameter(valueParameter: KSValueParameter, data: KSNode?): Boolean {
+        return valueParameter.type.accept(this, valueParameter)
     }
 }

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/processor/ValidateProcessor.kt

@@ -22,10 +22,12 @@ class ValidateProcessor : AbstractTestProcessor() {
         val GoodClass = resolver.getClassDeclarationByName("GoodClass")!!
         val C = resolver.getClassDeclarationByName("C")!!
         val BadJavaClass = resolver.getClassDeclarationByName("BadJavaClass")!!
+        val ErrorAnnotationType = resolver.getClassDeclarationByName("ErrorAnnotationType")!!
         validate(ErrorInMember)
         ErrorInMember.declarations.map { validate(it) }
         validate(GoodClass)
         validate(C)
         validate(BadJavaClass)
+        validate(ErrorAnnotationType)
     }
 }

compiler-plugin/testData/api/validateTypes.kt

@@ -7,15 +7,24 @@
 // GoodClass valid
 // C valid
 // BadJavaClass invalid
+// ErrorAnnotationType invalid
 // END
 // FILE: a.kt
+annotation class Anno(val i: Int)
+
+@Anno(1)
 class ErrorInMember : C {
     val goodProp: Int
     fun errorFun(): NonExistType {
 
     }
 }
 
+@NonExistAnnotation
+class ErrorAnnotationType {
+}
+
+@Anno(1)
 open class GoodClass {
     val a: Int