[FIR] Support the simple case of java field interpretation

#KT-57802

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt

@@ -14,7 +14,6 @@ import org.jetbrains.kotlin.backend.common.actualizer.FakeOverrideRebuilder
 import org.jetbrains.kotlin.backend.common.sourceElement
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.config.LanguageFeature
-import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.*
@@ -31,28 +30,32 @@ import org.jetbrains.kotlin.fir.extensions.declarationGenerators
 import org.jetbrains.kotlin.fir.extensions.extensionService
 import org.jetbrains.kotlin.fir.extensions.generatedMembers
 import org.jetbrains.kotlin.fir.extensions.generatedNestedClassifiers
+import org.jetbrains.kotlin.fir.java.javaElementFinder
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.symbols.lazyDeclarationResolver
 import org.jetbrains.kotlin.fir.types.resolvedType
-import org.jetbrains.kotlin.ir.PsiIrFileEntry
 import org.jetbrains.kotlin.ir.IrBuiltIns
+import org.jetbrains.kotlin.ir.PsiIrFileEntry
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
+import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.impl.IrDelegatingConstructorCallImpl
 import org.jetbrains.kotlin.ir.interpreter.IrInterpreter
 import org.jetbrains.kotlin.ir.interpreter.IrInterpreterConfiguration
 import org.jetbrains.kotlin.ir.interpreter.IrInterpreterEnvironment
 import org.jetbrains.kotlin.ir.interpreter.checker.EvaluationMode
+import org.jetbrains.kotlin.ir.interpreter.transformer.evaluate
 import org.jetbrains.kotlin.ir.interpreter.transformer.transformConst
 import org.jetbrains.kotlin.ir.overrides.IrFakeOverrideBuilder
-import org.jetbrains.kotlin.ir.types.IrTypeSystemContext
 import org.jetbrains.kotlin.ir.symbols.impl.IrConstructorPublicSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrSimpleFunctionPublicSymbolImpl
+import org.jetbrains.kotlin.ir.types.IrTypeSystemContext
 import org.jetbrains.kotlin.ir.util.KotlinMangler
 import org.jetbrains.kotlin.ir.util.NaiveSourceBasedFileEntryImpl
 import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.fileOrNull
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
 
@@ -107,7 +110,7 @@ class Fir2IrConverter(
             }
         }
 
-        evaluateConstants(irModuleFragment, configuration)
+        evaluateConstants(irModuleFragment, components)
     }
 
     fun bindFakeOverridesOrPostpone(declarations: List<IrDeclaration>) {
@@ -528,7 +531,8 @@ class Fir2IrConverter(
     }
 
     companion object {
-        private fun evaluateConstants(irModuleFragment: IrModuleFragment, fir2IrConfiguration: Fir2IrConfiguration) {
+        private fun evaluateConstants(irModuleFragment: IrModuleFragment, components: Fir2IrComponents) {
+            val fir2IrConfiguration = components.configuration
             val firModuleDescriptor = irModuleFragment.descriptor as? FirModuleDescriptor
             val targetPlatform = firModuleDescriptor?.platform
             val languageVersionSettings = firModuleDescriptor?.session?.languageVersionSettings ?: return
@@ -538,8 +542,30 @@ class Fir2IrConverter(
                 platform = targetPlatform,
                 printOnlyExceptionMessage = true,
             )
+
             val interpreter = IrInterpreter(IrInterpreterEnvironment(irModuleFragment.irBuiltins, configuration))
             val mode = if (intrinsicConstEvaluation) EvaluationMode.ONLY_INTRINSIC_CONST else EvaluationMode.ONLY_BUILTINS
+
+            components.session.javaElementFinder?.propertyEvaluator = eval@{ firProperty ->
+                val irProperty = components.declarationStorage.getCachedIrProperty(firProperty, fakeOverrideOwnerLookupTag = null) ?: return@eval null
+
+                fun IrProperty.tryToGetConst(): IrConst<*>? {
+                    return (backingField?.initializer?.expression as? IrConst<*>)
+                }
+
+                irProperty.tryToGetConst()?.let { return@eval it.value.toString() }
+                val irFile = irProperty.fileOrNull ?: return@eval null
+                // Note: can't evaluate all expressions in given file, because we can accidentally get recursive processing and
+                // second call of `Fir2IrLazyField.initializer` will return null
+                val evaluated = irProperty.evaluate(
+                    irFile, interpreter, mode,
+                    evaluatedConstTracker = fir2IrConfiguration.evaluatedConstTracker,
+                    inlineConstTracker = fir2IrConfiguration.inlineConstTracker,
+                )
+
+                return@eval evaluated?.tryToGetConst()?.value?.toString()
+            }
+
             val ktDiagnosticReporter = KtDiagnosticReporterWithImplicitIrBasedContext(fir2IrConfiguration.diagnosticReporter, languageVersionSettings)
             irModuleFragment.files.forEach {
                 it.transformConst(

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -29167,6 +29167,12 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java

@@ -29167,6 +29167,12 @@ public class FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -29167,6 +29167,12 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/FirJavaElementFinder.kt

@@ -9,6 +9,7 @@ import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Pair
 import com.intellij.psi.*
 import com.intellij.psi.impl.cache.ModifierFlags
+import com.intellij.psi.impl.cache.TypeInfo
 import com.intellij.psi.impl.compiled.ClsClassImpl
 import com.intellij.psi.impl.compiled.ClsFileImpl
 import com.intellij.psi.impl.file.PsiPackageImpl
@@ -24,12 +25,14 @@ import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.FirSessionComponent
+import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.declarations.utils.classId
 import org.jetbrains.kotlin.fir.declarations.utils.isInner
 import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.declarations.utils.visibility
+import org.jetbrains.kotlin.fir.expressions.FirConstExpression
 import org.jetbrains.kotlin.fir.moduleData
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
@@ -48,11 +51,14 @@ import org.jetbrains.kotlin.utils.exceptions.errorWithAttachment
 
 val FirSession.javaElementFinder: FirJavaElementFinder? by FirSession.nullableSessionComponentAccessor<FirJavaElementFinder>()
 
+private typealias PropertyEvaluator = (FirProperty) -> String?
+
 class FirJavaElementFinder(
     private val session: FirSession,
     project: Project
 ) : PsiElementFinder(), KotlinFinderMarker, FirSessionComponent {
     private val psiManager = PsiManager.getInstance(project)
+    var propertyEvaluator: PropertyEvaluator? = null
 
     private val firProviders: List<FirProvider> = buildList {
         add(session.firProvider)
@@ -111,6 +117,18 @@ class FirJavaElementFinder(
             )
         )
 
+        val classProperties = firClass.declarations.filterIsInstance<FirProperty>()
+        // Note: we must store companion properties in outer clas because java resolver will not find it other way.
+        val companionProperties = firClass.companionObjectSymbol?.declarationSymbols?.map { it.fir }?.filterIsInstance<FirProperty>() ?: emptyList()
+        (classProperties + companionProperties).forEach {
+            // TODO correct type info
+            val psiField = PsiFieldStubImpl(
+                stub, it.name.identifier, TypeInfo.fromString("int"), propertyEvaluator?.invoke(it),
+                PsiFieldStubImpl.packFlags(false, false, false, false)
+            )
+            PsiModifierListStubImpl(psiField, ModifierFlags.PUBLIC_MASK + ModifierFlags.FINAL_MASK + ModifierFlags.STATIC_MASK)
+        }
+
         PsiModifierListStubImpl(stub, firClass.packFlags())
 
         newTypeParameterList(

compiler/ir/ir.interpreter/src/org/jetbrains/kotlin/ir/interpreter/transformer/IrConstTransformer.kt

@@ -75,6 +75,24 @@ fun IrFile.runConstOptimizations(
     preprocessedFile.transform(irConstExpressionTransformer, IrConstTransformer.Data())
 }
 
+// TODO simplify
+fun IrProperty.evaluate(
+    irFile: IrFile,
+    interpreter: IrInterpreter,
+    mode: EvaluationMode,
+    evaluatedConstTracker: EvaluatedConstTracker? = null,
+    inlineConstTracker: InlineConstTracker? = null,
+    onWarning: (IrFile, IrElement, IrErrorExpression) -> Unit = { _, _, _ -> },
+    onError: (IrFile, IrElement, IrErrorExpression) -> Unit = { _, _, _ -> },
+    suppressExceptions: Boolean = false,
+): IrProperty? {
+    val checker = IrInterpreterCommonChecker()
+    val irConstExpressionTransformer = IrConstAllTransformer(
+        interpreter, irFile, mode, checker, evaluatedConstTracker, inlineConstTracker, onWarning, onError, suppressExceptions
+    )
+    return this.transform(irConstExpressionTransformer, IrConstTransformer.Data()) as? IrProperty
+}
+
 private fun IrFile.preprocessForConstTransformer(
     interpreter: IrInterpreter,
     mode: EvaluationMode,
@@ -88,7 +106,7 @@ private fun IrFile.preprocessForConstTransformer(
 
 // Note: We are using `IrElementTransformer` here instead of `IrElementTransformerVoid` to avoid conflicts with `IrTypeVisitorVoid`
 // that is used later in `IrConstTypeAnnotationTransformer`.
-internal abstract class IrConstTransformer(
+abstract class IrConstTransformer(
     protected val interpreter: IrInterpreter,
     private val irFile: IrFile,
     private val mode: EvaluationMode,

compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt

@@ -0,0 +1,39 @@
+// TARGET_BACKEND: JVM
+// FILE: Bar.java
+package one.two;
+
+public class Bar {
+    public static final int BAR = Doo.DOO + 1;
+}
+
+// FILE: Boo.java
+package one.two;
+
+public class Boo {
+    public static final int BOO = Baz.BAZ + 1;
+}
+
+// FILE: Main.kt
+package one.two
+
+class Foo {
+    companion object {
+        const val FOO = <!EVALUATED("5")!>Boo.BOO + 1<!>
+    }
+}
+
+class Baz {
+    companion object {
+        const val BAZ = <!EVALUATED("3")!>Bar.BAR + 1<!>
+    }
+}
+
+class Doo {
+    companion object {
+        const val DOO = <!EVALUATED("1")!>1<!>
+    }
+}
+
+fun box(): String {
+    return "OK"
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -27823,6 +27823,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57028.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -29167,6 +29167,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java

@@ -29167,6 +29167,12 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @Test
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @Test
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -24625,6 +24625,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57313.kt");
         }
 
+        @TestMetadata("kt57802.kt")
+        public void testKt57802() throws Exception {
+            runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt57802.kt");
+        }
+
         @TestMetadata("kt58005.kt")
         public void testKt58005() throws Exception {
             runTest("compiler/testData/codegen/box/involvesIrInterpreter/kt58005.kt");