Merge pull request #17881 from tamasvajk/ke2-safe-qualified-expr

KE2: Extract safe qualified expressions

Author: tamasvajk

java/kotlin-extractor2/src/main/kotlin/entities/Expression.kt

@@ -344,7 +344,7 @@ private fun KotlinFileExtractor.extractExpression(
                 extractExpression(e.baseExpression!!, callable, parent)
             }
 
-            is KtDotQualifiedExpression -> {
+            is KtQualifiedExpression -> {
                 // We're propagating the extraction to the child, and then getting the qualifier from the parent of the
                 // child. The selector could be many expression kind, such as KtCallExpression, KtReferenceExpression,
                 // and each of those would need to look for the qualifier

java/kotlin-extractor2/src/main/kotlin/entities/MethodCall.kt

@@ -6,8 +6,9 @@ import org.jetbrains.kotlin.analysis.api.resolution.symbol
 import org.jetbrains.kotlin.analysis.api.symbols.KaFunctionSymbol
 import org.jetbrains.kotlin.analysis.api.types.KaType
 import org.jetbrains.kotlin.psi.KtCallExpression
-import org.jetbrains.kotlin.psi.KtDotQualifiedExpression
 import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.KtQualifiedExpression
+import org.jetbrains.kotlin.psi.KtSafeQualifiedExpression
 import org.jetbrains.kotlin.utils.mapToIndex
 
 context(KaSession)
@@ -43,14 +44,15 @@ fun KotlinFileExtractor.extractMethodCall(
         .sortedBy { p -> p.first }
         .map { p -> p.second }
 
-    // TODO: fix getting the qualifier, we should handle safe qualified expressions too
-    val qualifier: KtExpression? = (call.parent as? KtDotQualifiedExpression)?.receiverExpression
+    val callQualifiedParent = call.parent as? KtQualifiedExpression
+    val qualifier =
+        if (callQualifiedParent?.selectorExpression == call) callQualifiedParent.receiverExpression else null
     val extensionReceiver = if (target.isExtension) qualifier else null
     val dispatchReceiver = if (!target.isExtension) qualifier else null
 
     val exprParent = stmtExprParent.expr(call, enclosingCallable)
 
-    extractRawMethodAccess(
+    val callId = extractRawMethodAccess(
         target,
         tw.getLocation(call),
         call.expressionType!!,
@@ -62,6 +64,10 @@ fun KotlinFileExtractor.extractMethodCall(
         extensionReceiver,
         args
     )
+
+    if (call.parent is KtSafeQualifiedExpression) {
+        tw.writeKtSafeAccess(callId)
+    }
 }
 
 context(KaSession)
@@ -138,7 +144,7 @@ private fun KotlinFileExtractor.extractRawMethodAccess(
     extractClassTypeArguments: Boolean = false,
     superQualifierSymbol: IrClassSymbol? = null
      */
-) {
+): Label<DbMethodaccess> {
     /* OLD KE1:
     val callTarget = getCalleeRealOverrideTarget(syntacticCallTarget)
     val methodId = getCalleeMethodId(callTarget, drType, extractClassTypeArguments)
@@ -229,6 +235,8 @@ private fun KotlinFileExtractor.extractRawMethodAccess(
     }
     val idxOffset = if (extensionReceiver != null) 1 else 0
     extractCallValueArguments(id, valueArguments, enclosingStmt, enclosingCallable, idxOffset)
+
+    return id
 }
 
 context(KaSession)

java/ql/lib/config/semmlecode.dbscheme

@@ -1528,3 +1528,10 @@ ktFunctionOriginalNames(
 ktDataClasses(
   unique int id: @classorinterface ref
 )
+
+// not all variables are qualifiable, but adding fieldaccess would be more involved:
+@qualifiableaccess = @varaccess | @methodaccess;
+
+ktSafeAccess(
+    unique int id: @qualifiableaccess ref
+)

java/ql/lib/semmle/code/java/Expr.qll

@@ -2360,6 +2360,9 @@ private module Qualifier {
       result = this.(FieldAccess).getQualifier() or
       result = this.(MethodCall).getQualifier()
     }
+
+    /** Holds if this member access is a `?.` safe qualified expression in Kotlin. */
+    predicate safeAccess() { ktSafeAccess(this) }
   }
 
   /**