FIR IDE: check backing field with BODY_RESOLVE

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtVariableLikeSymbol.kt

@@ -6,11 +6,11 @@
 package org.jetbrains.kotlin.idea.frontend.api.symbols
 
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.*
 import org.jetbrains.kotlin.idea.frontend.api.symbols.pointers.KtSymbolPointer
 import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.ClassId
-import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 
 public sealed class KtVariableLikeSymbol : KtCallableSymbol(), KtNamedSymbol, KtSymbolWithKind {
@@ -42,7 +42,7 @@ public abstract class KtBackingFieldSymbol : KtVariableLikeSymbol() {
     abstract override fun createPointer(): KtSymbolPointer<KtVariableLikeSymbol>
 
     public companion object {
-        private val fieldName = Name.identifier("field")
+        private val fieldName = StandardNames.BACKING_FIELD
     }
 }
 
@@ -53,7 +53,6 @@ public abstract class KtEnumEntrySymbol : KtVariableLikeSymbol(), KtSymbolWithMe
     final override val receiverType: KtTypeAndAnnotations? get() = null
     public abstract val containingEnumClassIdIfNonLocal: ClassId?
 
-
     abstract override fun createPointer(): KtSymbolPointer<KtEnumEntrySymbol>
 }
 

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirKotlinPropertySymbol.kt

@@ -97,7 +97,8 @@ internal class KtFirKotlinPropertySymbol(
         property.setter?.let { builder.callableBuilder.buildPropertyAccessorSymbol(it) } as? KtPropertySetterSymbol
     }
 
-    override val hasBackingField: Boolean get() = firRef.withFir { it.hasBackingField }
+    // NB: `field` in accessors indicates the property should have a backing field. To see that, though, we need BODY_RESOLVE.
+    override val hasBackingField: Boolean get() = firRef.withFir(FirResolvePhase.BODY_RESOLVE) { it.hasBackingField }
 
     override val isLateInit: Boolean get() = firRef.withFir { it.isLateInit }
 

idea/idea-frontend-fir/testData/symbols/symbolByPsi/backingField.kt

@@ -0,0 +1,5 @@
+var p: Int
+    get() = field
+    set(value) {
+        field = value
+    }

idea/idea-frontend-fir/testData/symbols/symbolByPsi/backingField.txt

@@ -0,0 +1,87 @@
+KtFirPropertyGetterSymbol:
+  annotatedType: [] kotlin/Int
+  annotationClassIds: []
+  annotations: []
+  callableIdIfNonLocal: null
+  dispatchType: null
+  hasBody: true
+  hasStableParameterNames: true
+  isDefault: false
+  isExtension: false
+  isInline: false
+  isOverride: false
+  modality: FINAL
+  origin: SOURCE
+  receiverType: null
+  symbolKind: ACCESSOR
+  valueParameters: []
+  visibility: Public
+  deprecationStatus: null
+
+KtFirValueParameterSymbol:
+  annotatedType: [] kotlin/Int
+  annotationClassIds: []
+  annotations: []
+  callableIdIfNonLocal: null
+  hasDefaultValue: false
+  isExtension: false
+  isVararg: false
+  name: value
+  origin: SOURCE
+  receiverType: null
+  symbolKind: LOCAL
+  deprecationStatus: null
+
+KtFirPropertySetterSymbol:
+  annotatedType: [] kotlin/Unit
+  annotationClassIds: []
+  annotations: []
+  callableIdIfNonLocal: null
+  dispatchType: null
+  hasBody: true
+  hasStableParameterNames: true
+  isDefault: false
+  isExtension: false
+  isInline: false
+  isOverride: false
+  modality: FINAL
+  origin: SOURCE
+  parameter: KtFirValueParameterSymbol(value)
+  receiverType: null
+  symbolKind: ACCESSOR
+  valueParameters: [
+    KtFirValueParameterSymbol(value)
+  ]
+  visibility: Public
+  deprecationStatus: null
+
+KtFirKotlinPropertySymbol:
+  annotatedType: [] kotlin/Int
+  annotationClassIds: []
+  annotations: []
+  callableIdIfNonLocal: /p
+  dispatchType: null
+  getter: KtFirPropertyGetterSymbol(<getter>)
+  hasBackingField: true
+  hasGetter: true
+  hasSetter: true
+  initializer: null
+  isConst: false
+  isExtension: false
+  isFromPrimaryConstructor: false
+  isLateInit: false
+  isOverride: false
+  isStatic: false
+  isVal: false
+  modality: FINAL
+  name: p
+  origin: SOURCE
+  receiverType: null
+  setter: KtFirPropertySetterSymbol(<setter>)
+  symbolKind: TOP_LEVEL
+  visibility: Public
+  deprecationStatus: null
+  getterDeprecationStatus: null
+  javaGetterName: getP
+  javaSetterName: setP
+  setterDeprecationStatus: null

idea/idea-frontend-fir/tests/org/jetbrains/kotlin/idea/fir/frontend/api/symbols/SymbolByPsiTestGenerated.java

@@ -36,6 +36,12 @@ public class SymbolByPsiTestGenerated extends AbstractSymbolByPsiTest {
         runTest("idea/idea-frontend-fir/testData/symbols/symbolByPsi/anonymousObject.kt");
     }
 
+    @Test
+    @TestMetadata("backingField.kt")
+    public void testBackingField() throws Exception {
+        runTest("idea/idea-frontend-fir/testData/symbols/symbolByPsi/backingField.kt");
+    }
+
     @Test
     @TestMetadata("class.kt")
     public void testClass() throws Exception {