Merge pull request #979 from Kotlin/cast-target-warning

[Compiler plugin] Add warning to avoid confusion with missing extension properties

Author: koperagen

plugins/kotlin-dataframe/src/org/jetbrains/kotlinx/dataframe/plugin/extensions/ExpressionAnalysisAdditionalChecker.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.SourceElementPositioningStrategies
 import org.jetbrains.kotlin.diagnostics.error1
 import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.diagnostics.warning1
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.MppCheckerKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
@@ -29,6 +30,7 @@ import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.fir.types.isSubtypeOf
 import org.jetbrains.kotlin.fir.types.renderReadable
 import org.jetbrains.kotlin.fir.types.resolvedType
+import org.jetbrains.kotlin.fir.types.toSymbol
 import org.jetbrains.kotlin.fir.types.type
 import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.ClassId
@@ -38,6 +40,7 @@ import org.jetbrains.kotlin.psi.KtElement
 import org.jetbrains.kotlinx.dataframe.plugin.impl.PluginDataFrameSchema
 import org.jetbrains.kotlinx.dataframe.plugin.impl.SimpleDataColumn
 import org.jetbrains.kotlinx.dataframe.plugin.impl.type
+import org.jetbrains.kotlinx.dataframe.plugin.utils.Names
 
 class ExpressionAnalysisAdditionalChecker(
     session: FirSession,
@@ -58,6 +61,7 @@ private class Checker(
     companion object {
         val ERROR by error1<KtElement, String>(SourceElementPositioningStrategies.DEFAULT)
         val CAST_ERROR by error1<KtElement, String>(SourceElementPositioningStrategies.CALL_ELEMENT_WITH_DOT)
+        val CAST_TARGET_WARNING by warning1<KtElement, String>(SourceElementPositioningStrategies.CALL_ELEMENT_WITH_DOT)
         val CAST_ID = CallableId(FqName.fromSegments(listOf("org", "jetbrains", "kotlinx", "dataframe", "api")), Name.identifier("cast"))
         val CHECK = ClassId(FqName("org.jetbrains.kotlinx.dataframe.annotations"), Name.identifier("Check"))
     }
@@ -87,13 +91,18 @@ private class Checker(
             || !calleeReference.resolvedSymbol.hasAnnotation(CHECK, session)) {
             return
         }
+        val targetProjection = expression.typeArguments.getOrNull(0) as? FirTypeProjectionWithVariance ?: return
+        val targetType = targetProjection.typeRef.coneType as? ConeClassLikeType ?: return
+        val targetSymbol = targetType.toSymbol(session)
+        if (targetSymbol != null && !targetSymbol.hasAnnotation(Names.DATA_SCHEMA_CLASS_ID, session)) {
+            val text = "Annotate ${targetType.renderReadable()} with @DataSchema to use generated properties"
+            reporter.reportOn(expression.source, CAST_TARGET_WARNING, text, context)
+        }
         val coneType = expression.explicitReceiver?.resolvedType
         if (coneType != null) {
             val sourceType = coneType.fullyExpandedType(session).typeArguments.getOrNull(0)?.type as? ConeClassLikeType
                 ?: return
             val source = pluginDataFrameSchema(sourceType)
-            val targetProjection = expression.typeArguments.getOrNull(0) as? FirTypeProjectionWithVariance ?: return
-            val targetType = targetProjection.typeRef.coneType as? ConeClassLikeType ?: return
             val target = pluginDataFrameSchema(targetType)
             val sourceColumns = source.flatten(includeFrames = true)
             val targetColumns = target.flatten(includeFrames = true)

plugins/kotlin-dataframe/testData/diagnostics/targetOfCastIsNotDataSchema.fir.txt

@@ -0,0 +1,11 @@
+FILE: targetOfCastIsNotDataSchema.kt
+    public abstract interface MySchema : R|kotlin/Any| {
+        public abstract val a: R|kotlin/String|
+            public get(): R|kotlin/String|
+
+    }
+    public final fun box(): R|kotlin/String| {
+        lval df: R|{org/jetbrains/kotlinx/dataframe/AnyFrame=} org/jetbrains/kotlinx/dataframe/DataFrame<*>| = Q|org/jetbrains/kotlinx/dataframe/DataFrame|.R|org/jetbrains/kotlinx/dataframe/DataFrame.Companion.Empty|
+        R|<local>/df|.R|org/jetbrains/kotlinx/dataframe/api/cast|<R|MySchema|>()
+        ^box String(OK)
+    }

plugins/kotlin-dataframe/testData/diagnostics/targetOfCastIsNotDataSchema.kt

@@ -0,0 +1,13 @@
+import org.jetbrains.kotlinx.dataframe.*
+import org.jetbrains.kotlinx.dataframe.annotations.*
+import org.jetbrains.kotlinx.dataframe.api.*
+import org.jetbrains.kotlinx.dataframe.io.*
+
+interface MySchema {
+    val a: String
+}
+fun box(): String {
+    val df = DataFrame.Empty
+    <!CAST_TARGET_WARNING!>df.cast<MySchema>()<!>
+    return "OK"
+}

plugins/kotlin-dataframe/tests-gen/org/jetbrains/kotlin/fir/dataframe/DataFrameDiagnosticTestGenerated.java

@@ -44,6 +44,12 @@ public void testStructuralCast() {
     runTest("testData/diagnostics/structuralCast.kt");
   }
 
+  @Test
+  @TestMetadata("targetOfCastIsNotDataSchema.kt")
+  public void testTargetOfCastIsNotDataSchema() {
+    runTest("testData/diagnostics/targetOfCastIsNotDataSchema.kt");
+  }
+
   @Test
   @TestMetadata("toDataFrame_java.kt")
   public void testToDataFrame_java() {