[ULC] Add constant evaluation to light classes service

compiler/light-classes/src/org/jetbrains/kotlin/asJava/LightClassGenerationSupport.kt

@@ -18,6 +18,8 @@ package org.jetbrains.kotlin.asJava
 
 import com.intellij.openapi.components.ServiceManager
 import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiConstantEvaluationHelper
+import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiManager
 import com.intellij.psi.util.CachedValue
 import org.jetbrains.kotlin.asJava.builder.LightClassBuilderResult

compiler/light-classes/src/org/jetbrains/kotlin/asJava/classes/ultraLightSupport.kt

@@ -9,12 +9,10 @@ import org.jetbrains.annotations.TestOnly
 import org.jetbrains.kotlin.asJava.LightClassGenerationSupport
 import org.jetbrains.kotlin.codegen.state.KotlinTypeMapper
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
-import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator
 import org.jetbrains.kotlin.resolve.deprecation.DeprecationResolver
-import java.util.concurrent.ConcurrentMap
 
 interface KtUltraLightSupport {
     val moduleName: String
@@ -23,6 +21,7 @@ interface KtUltraLightSupport {
     val moduleDescriptor: ModuleDescriptor
     val isReleasedCoroutine: Boolean
     fun hasAlias(file: KtFile, shortName: Name?): Boolean = false
+    fun getConstantEvaluator(expression: KtExpression): ConstantExpressionEvaluator
 
     companion object {
         // This property may be removed once IntelliJ versions earlier than 2018.3 become unsupported
@@ -52,4 +51,7 @@ class UltraLightSupportViaService(private val ktElement: KtElement) : KtUltraLig
 
     override val isReleasedCoroutine: Boolean
         get() = serviceProvidedSupport.isReleasedCoroutine
+
+    override fun getConstantEvaluator(expression: KtExpression): ConstantExpressionEvaluator =
+        serviceProvidedSupport.getConstantEvaluator(expression)
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightAnnotationsValues.kt

@@ -13,6 +13,7 @@ import com.intellij.psi.impl.light.LightTypeElement
 import org.jetbrains.kotlin.asJava.LightClassGenerationSupport
 import org.jetbrains.kotlin.asJava.classes.cannotModify
 import org.jetbrains.kotlin.asJava.classes.lazyPub
+import org.jetbrains.kotlin.asJava.computeExpression
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.name.FqNameUnsafe
 import org.jetbrains.kotlin.psi.*
@@ -39,8 +40,7 @@ open class KtLightPsiLiteral(
     private val lightParent: PsiElement
 ) : KtLightElementBase(lightParent), PsiLiteralExpression {
 
-    override fun getValue(): Any? =
-        LanguageConstantExpressionEvaluator.INSTANCE.forLanguage(kotlinOrigin.language)?.computeConstantExpression(this, false)
+    override fun getValue(): Any? = computeExpression(this)
 
     override fun getType(): PsiType? {
         val bindingContext = LightClassGenerationSupport.getInstance(this.project).analyze(kotlinOrigin)

compiler/light-classes/src/org/jetbrains/kotlin/asJava/lightClassUtils.kt

@@ -21,6 +21,7 @@ import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.asJava.classes.KtLightClass
 import org.jetbrains.kotlin.asJava.classes.KtLightClassForFacade
 import org.jetbrains.kotlin.asJava.classes.KtUltraLightElementWithNullabilityAnnotation
+import org.jetbrains.kotlin.asJava.classes.runReadAction
 import org.jetbrains.kotlin.asJava.elements.PsiElementWithOrigin
 import org.jetbrains.kotlin.asJava.elements.*
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
@@ -32,6 +33,10 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
+import org.jetbrains.kotlin.resolve.DelegatingBindingTrace
+import org.jetbrains.kotlin.resolve.constants.ArrayValue
+import org.jetbrains.kotlin.resolve.constants.ConstantValue
+import org.jetbrains.kotlin.types.TypeUtils
 
 /**
  * Can be null in scripts and for elements from non-jvm modules.
@@ -248,4 +253,31 @@ fun fastCheckIsNullabilityApplied(lightElement: KtLightElement<*, PsiModifierLis
     }
 
     return true
+}
+
+fun computeExpression(expression: PsiElement): Any? {
+    fun evalConstantValue(constantValue: ConstantValue<*>): Any? {
+        return if (constantValue is ArrayValue) {
+            val items = constantValue.value.map { evalConstantValue(it) }
+            items.singleOrNull() ?: items
+        } else constantValue.value
+    }
+
+    val expressionToCompute = when (expression) {
+        is KtLightElementBase -> expression.kotlinOrigin as? KtExpression ?: return null
+        else -> return null
+    }
+
+    val generationSupport = LightClassGenerationSupport.getInstance(expressionToCompute.project)
+    val evaluator = generationSupport
+        .getUltraLightClassSupport(expressionToCompute)
+        .getConstantEvaluator(expressionToCompute)
+
+    val constant = runReadAction {
+        val evaluatorTrace = DelegatingBindingTrace(generationSupport.analyze(expressionToCompute), "Evaluating annotation argument")
+        evaluator.evaluateExpression(expressionToCompute, evaluatorTrace)
+    } ?: return null
+
+    if (constant.isError) return null
+    return evalConstantValue(constant.toConstantValue(TypeUtils.NO_EXPECTED_TYPE))
 }