Kapt: Use constant value references where possible in property initializers

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/stubs/ClassFileToSourceStubConverter.kt

@@ -635,17 +635,32 @@ class ClassFileToSourceStubConverter(val kaptContext: KaptContextForStubGenerati
                 ifNonError = { signatureParser.parseFieldSignature(field.signature, treeMaker.Type(type)) }
             )
 
-        val value = field.value
-
-        val initializer = explicitInitializer
-            ?: convertValueOfPrimitiveTypeOrString(value)
-            ?: if (isFinal(field.access)) convertLiteralExpression(getDefaultValue(type)) else null
-
         lineMappings.registerField(containingClass, field)
 
+        val initializer = explicitInitializer ?: convertPropertyInitializer(field)
         return treeMaker.VarDef(modifiers, treeMaker.name(name), typeExpression, initializer).keepKdocComments(field)
     }
 
+    private fun convertPropertyInitializer(field: FieldNode): JCExpression? {
+        val value = field.value
+
+        if (value != null) {
+            val propertyInitializer = (kaptContext.origins[field]?.element as? KtProperty)?.initializer
+            if (propertyInitializer != null) {
+                return convertConstantValueArguments(value, listOf(propertyInitializer))
+            }
+
+            return convertValueOfPrimitiveTypeOrString(value)
+        }
+
+        if (isFinal(field.access)) {
+            val type = Type.getType(field.desc)
+            return convertLiteralExpression(getDefaultValue(type))
+        }
+
+        return null
+    }
+
     private fun convertMethod(
         method: MethodNode,
         containingClass: ClassNode,
@@ -987,12 +1002,12 @@ class ClassFileToSourceStubConverter(val kaptContext: KaptContextForStubGenerati
 
     private fun convertAnnotationArgumentWithName(constantValue: Any?, value: ResolvedValueArgument?, name: String): JCExpression? {
         if (!isValidIdentifier(name)) return null
-        val expr = convertAnnotationArgument(constantValue, value) ?: return null
+        val args = value?.arguments?.mapNotNull { it.getArgumentExpression() } ?: emptyList()
+        val expr = convertConstantValueArguments(constantValue, args) ?: return null
         return treeMaker.Assign(treeMaker.SimpleName(name), expr)
     }
 
-    private fun convertAnnotationArgument(constantValue: Any?, value: ResolvedValueArgument?): JCExpression? {
-        val args = value?.arguments?.mapNotNull { it.getArgumentExpression() } ?: emptyList()
+    private fun convertConstantValueArguments(constantValue: Any?, args: List<KtExpression>): JCExpression? {
         val singleArg = args.singleOrNull()
 
         if (constantValue.isOfPrimitiveType()) {

plugins/kapt3/kapt3-compiler/testData/converter/kt18791.kt

@@ -110,6 +110,20 @@ class MyActivity {
 
     @Bind(B.id.textView)
     fun plainIntConstant() {}
+
+    const val propA = B.id.textView
+    val propB = B.id.textView
+    var propC = B.id.textView
+    @JvmField
+    val propD = B.id.textView
+    @JvmField
+    var propE = B.id.textView
+    val propF = JJ.b.length
+}
+
+object JJ {
+    val b = c()
+    fun c() = "42"
 }
 
 // EXPECTED_ERROR class B is public, should be declared in a file named B.java

plugins/kapt3/kapt3-compiler/testData/converter/kt18791.txt

@@ -87,6 +87,33 @@ package app;
 
 import java.lang.System;
 
+@kotlin.Metadata()
+public final class JJ {
+    @org.jetbrains.annotations.NotNull()
+    private static final java.lang.String b = null;
+    public static final app.JJ INSTANCE = null;
+
+    @org.jetbrains.annotations.NotNull()
+    public final java.lang.String getB() {
+        return null;
+    }
+
+    @org.jetbrains.annotations.NotNull()
+    public final java.lang.String c() {
+        return null;
+    }
+
+    private JJ() {
+        super();
+    }
+}
+
+////////////////////
+
+package app;
+
+import java.lang.System;
+
 @kotlin.Metadata()
 public final class MyActivity {
     @BindField(id = lib.R.id.textView)
@@ -101,6 +128,12 @@ public final class MyActivity {
     private final int e = 0;
     @BindField(id = app.B.id.textView)
     private final int f = 0;
+    public final int propA = app.B.id.textView;
+    private final int propB = app.B.id.textView;
+    private int propC;
+    public final int propD = app.B.id.textView;
+    public int propE;
+    private final int propF = 0;
 
     @Bind(id = lib.R.id.textView)
     public static void a$annotations() {
@@ -176,6 +209,21 @@ public final class MyActivity {
     public final void plainIntConstant() {
     }
 
+    public final int getPropB() {
+        return 0;
+    }
+
+    public final int getPropC() {
+        return 0;
+    }
+
+    public final void setPropC(int p0) {
+    }
+
+    public final int getPropF() {
+        return 0;
+    }
+
     public MyActivity() {
         super();
     }