FIR: Simplify supertypes scopes computation

2021-02-03 20:29:18 +03:00
parent 31b9be2d01
commit 6766c8fe47
2 changed files with 47 additions and 22 deletions
@@ -42,6 +42,39 @@ fun lookupSuperTypes(
    }
 }

+fun FirClass<*>.isThereLoopInSupertypes(session: FirSession): Boolean {
+    val visitedSymbols: MutableSet<FirClassifierSymbol<*>> = mutableSetOf()
+    val inProcess: MutableSet<FirClassifierSymbol<*>> = mutableSetOf()
+
+    var isThereLoop = false
+
+    fun dfs(current: FirClassifierSymbol<*>) {
+        if (current in visitedSymbols) return
+        if (!inProcess.add(current)) {
+            isThereLoop = true
+            return
+        }
+
+        when (val fir = current.fir) {
+            is FirClass<*> -> {
+                fir.superConeTypes.forEach {
+                    it.lookupTag.toSymbol(session)?.let(::dfs)
+                }
+            }
+            is FirTypeAlias -> {
+                fir.expandedConeType?.lookupTag?.toSymbol(session)?.let(::dfs)
+            }
+        }
+
+        visitedSymbols.add(current)
+        inProcess.remove(current)
+    }
+
+    dfs(symbol)
+
+    return isThereLoop
+}
+
 fun lookupSuperTypes(
    symbol: FirClassifierSymbol<*>,
    lookupInterfaces: Boolean,