ambiguity of implicit constructor call (IDEA-160248)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightClassUtil.java

@@ -528,6 +528,11 @@ public class HighlightClassUtil {
     PsiMethod[] constructors = baseClass.getConstructors();
     if (constructors.length == 0) return null;
 
+    final HighlightInfo highlightInfo = constructors.length > 1 ? checkAmbiguityOfImplicitConstructorCall(constructors, range) : null;
+    if (highlightInfo != null) {
+      return highlightInfo;
+    }
+
     for (PsiMethod constructor : constructors) {
       if (resolveHelper.isAccessible(constructor, aClass, null)) {
         if (constructor.getParameterList().getParametersCount() == 0 ||
@@ -556,6 +561,55 @@ public class HighlightClassUtil {
     return info;
   }
 
+  @Nullable
+  private static HighlightInfo checkAmbiguityOfImplicitConstructorCall(PsiMethod[] constructors, TextRange range) {
+    List<PsiMethod> varargConstructors = new ArrayList<>();
+    for (PsiMethod constructor : constructors) {
+      final PsiParameter[] parameters = constructor.getParameterList().getParameters();
+      if (parameters.length == 0) {
+        varargConstructors.clear();
+        break;
+      }
+      if (parameters.length == 1 && parameters[0].isVarArgs()) {
+        varargConstructors.add(constructor);
+      }
+    }
+
+    if (varargConstructors.size() <= 1) return null;
+    final PsiType[] types = varargConstructors.stream().map(c -> c.getParameterList().getParameters()[0].getType()).toArray(PsiType[]::new);
+    for (int i = 1; i < types.length; i++) {
+      PsiType t1 = types[i];
+      for (int j = 0; j < i; j++) {
+        PsiType t2 = types[j];
+
+        if (t1.isAssignableFrom(t2)) {
+          varargConstructors.remove(i);
+        }
+        else if (t2.isAssignableFrom(t1)) {
+          varargConstructors.remove(j);
+        }
+      }
+    }
+
+    if (varargConstructors.size() > 1) {
+      final String m1 = PsiFormatUtil.formatMethod(varargConstructors.get(0), PsiSubstitutor.EMPTY,
+                                                   PsiFormatUtilBase.SHOW_CONTAINING_CLASS |
+                                                   PsiFormatUtilBase.SHOW_NAME |
+                                                   PsiFormatUtilBase.SHOW_PARAMETERS,
+                                                   PsiFormatUtilBase.SHOW_TYPE);
+      final String m2 = PsiFormatUtil.formatMethod(varargConstructors.get(1), PsiSubstitutor.EMPTY,
+                                                   PsiFormatUtilBase.SHOW_CONTAINING_CLASS |
+                                                   PsiFormatUtilBase.SHOW_NAME |
+                                                   PsiFormatUtilBase.SHOW_PARAMETERS,
+                                                   PsiFormatUtilBase.SHOW_TYPE);
+      return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
+        .range(range)
+        .descriptionAndTooltip(JavaErrorMessages.message("ambiguous.method.call", m1, m2))
+        .create();
+    }
+    return null;
+  }
+
   @Nullable
   static HighlightInfo checkInterfaceCannotBeLocal(PsiClass aClass) {
     if (PsiUtil.isLocalClass(aClass)) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting6/AmbiguityChecksForImplicitSuperConstructorCall.java

@@ -0,0 +1,28 @@
+
+class A {
+  A(String... i) {}
+  A(Integer... i) {}
+}
+class B extends A {
+  <error descr="Ambiguous method call: both 'A.A(String...)' and 'A.A(Integer...)' match">public B()</error> {}
+}
+<error descr="Ambiguous method call: both 'A.A(String...)' and 'A.A(Integer...)' match">class C extends A</error> {}
+
+class A1 {
+  A1(String... i){}
+  A1(Object... i){}
+}
+class B1 extends A1 {
+  public B1() {}
+}
+class C1 extends A1 {}
+
+class A2 {
+  A2(int... i){}
+  A2(Object... i){}
+}
+class B2 extends A2 {
+  <error descr="Ambiguous method call: both 'A2.A2(int...)' and 'A2.A2(Object...)' match">public B2()</error> {
+  }
+}
+<error descr="Ambiguous method call: both 'A2.A2(int...)' and 'A2.A2(Object...)' match">class C2 extends A2</error> {}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk6Test.java

@@ -82,4 +82,8 @@ public class LightAdvHighlightingJdk6Test extends LightDaemonAnalyzerTestCase {
   public void testEnumConstantWithoutInterfaceImplementation() throws Exception {
     doTest(false, false);
   }
+
+  public void testAmbiguityChecksForImplicitSuperConstructorCall() {
+    doTest(false, false);
+  }
 }