SONARJAVA-4142 Revert support of constructors in S1450

its/ruling/src/test/resources/eclipse-jetty/java-S1450.json

@@ -1,15 +1,8 @@
 {
-'org.eclipse.jetty:jetty-project:jetty-server/src/main/java/org/eclipse/jetty/server/HttpOutput.java':[
-1825,
-],
 'org.eclipse.jetty:jetty-project:jetty-server/src/main/java/org/eclipse/jetty/server/PushBuilderImpl.java':[
 59,
 ],
 'org.eclipse.jetty:jetty-project:jetty-server/src/main/java/org/eclipse/jetty/server/resource/ByteBufferRangeWriter.java':[
 33,
 ],
-'org.eclipse.jetty:jetty-project:jetty-util/src/main/java/org/eclipse/jetty/util/DateCache.java':[
-49,
-51,
-],
 }

java-checks/src/main/java/org/sonar/java/checks/PrivateFieldUsedLocallyCheck.java

@@ -101,7 +101,7 @@ private static MethodTree usedInOneMethodOnly(Symbol privateFieldSymbol, TypeSym
     MethodTree method = null;
 
     for (IdentifierTree usageIdentifier : privateFieldSymbol.usages()) {
-      MethodTree enclosingMethod = ExpressionUtils.getEnclosingMethod(usageIdentifier);
+      MethodTree enclosingMethod = ExpressionUtils.getEnclosingElement(usageIdentifier, Kind.METHOD);
 
       if (enclosingMethod == null
         || !enclosingMethod.symbol().owner().equals(classSymbol)

java-checks/src/test/files/checks/PrivateFieldUsedLocallyCheck.java

@@ -227,11 +227,19 @@ void method2() {
 
   }
 
-  // Constructor are also supported
+  // Constructors
   class Class17 {
-    private int privateField; // Noncompliant
+    private int privateField; // Compliant: this field should be reported by S1068 (unused field), and not by this rule
     Class17() {
+      this.privateField = 5;
+    }
+  }
+
+  class Class18 {
+    private int privateField; // Not reported by S1068, we could decide to report it in this rule (see SONARJAVA-4142).
+    Class18() {
       privateField = 5;
+      System.out.println(privateField);
     }
   }
 }

java-frontend/src/main/java/org/sonar/java/model/ExpressionUtils.java

@@ -166,10 +166,18 @@ public static IdentifierTree methodName(MethodInvocationTree mit) {
     return id;
   }
 
+  /**
+   * Return the first enclosing method or constructor containing the given expression.
+   */
   @CheckForNull
   public static MethodTree getEnclosingMethod(ExpressionTree expr) {
+    return getEnclosingElement(expr, Tree.Kind.METHOD, Tree.Kind.CONSTRUCTOR);
+  }
+
+  @CheckForNull
+  public static MethodTree getEnclosingElement(ExpressionTree expr, Tree.Kind... kinds) {
     Tree result = expr.parent();
-    while (result != null && !result.is(Tree.Kind.METHOD, Tree.Kind.CONSTRUCTOR)) {
+    while (result != null && !result.is(kinds)) {
       result = result.parent();
     }
     return (MethodTree) result;