/*
 * Copyright 2018 The Error Prone Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.errorprone.util;

import java.lang.reflect.Method;

/** JDK version string utilities. */
public final class RuntimeVersion {

  private static final int MAJOR = getMajor();

  private static int getMajor() {
    try {
      Method versionMethod = Runtime.class.getMethod("version");
      Object version = versionMethod.invoke(null);
      return (int) version.getClass().getMethod("major").invoke(version);
    } catch (Exception e) {
      // continue below
    }

    int version = (int) Double.parseDouble(System.getProperty("java.class.version"));
    if (49 <= version && version <= 52) {
      return version - (49 - 5);
    }
    throw new IllegalStateException(
        "Unknown Java version: " + System.getProperty("java.specification.version"));
  }

  /** Returns true if the current runtime is JDK 8 or newer. */
  public static boolean isAtLeast8() {
    return MAJOR >= 8;
  }

  /** Returns true if the current runtime is JDK 9 or newer. */
  public static boolean isAtLeast9() {
    return MAJOR >= 9;
  }

  /** Returns true if the current runtime is JDK 10 or newer. */
  public static boolean isAtLeast10() {
    return MAJOR >= 10;
  }

  /** Returns true if the current runtime is JDK 10 or earlier. */
  public static boolean isAtMost10() {
    return MAJOR <= 10;
  }

  /** Returns true if the current runtime is JDK 11 or newer. */
  public static boolean isAtLeast11() {
    return MAJOR >= 11;
  }

  /** Returns true if the current runtime is JDK 12 or newer. */
  public static boolean isAtLeast12() {
    return MAJOR >= 12;
  }

  /** Returns true if the current runtime is JDK 13 or newer. */
  public static boolean isAtLeast13() {
    return MAJOR >= 13;
  }

  /** Returns true if the current runtime is JDK 14 or newer. */
  public static boolean isAtLeast14() {
    return MAJOR >= 14;
  }

  /** Returns true if the current runtime is JDK 15 or newer. */
  public static boolean isAtLeast15() {
    return MAJOR >= 15;
  }

  /** Returns true if the current runtime is JDK 16 or newer. */
  public static boolean isAtLeast16() {
    return MAJOR >= 16;
  }

  /** Returns true if the current runtime is JDK 17 or newer. */
  public static boolean isAtLeast17() {
    return MAJOR >= 17;
  }

  /**
   * Returns the latest {@code --release} version.
   *
   * <p>Prefer the {@code isAtLeast} methods for assumption checks in tests.
   */
  public static int release() {
    return MAJOR;
  }

  private RuntimeVersion() {}
}

@@ -643,42 +643,8 @@
 l;%0A%0A
-import java.lang.reflect.Method;%0A%0A
 /** 
@@ -744,615 +744,46 @@
 int 
-MAJOR = getMajor();%0A%0A  private static int getMajor() %7B%0A    try %7B%0A      Method versionMethod = Runtime.class.getMethod(%22version%22);%0A      Object version = versionMethod.invoke(null);%0A      return (int) version.getClass().getMethod(%22major%22).invoke(version);%0A    %7D catch (Exception e) %7B%0A      // continue below%0A    %7D%0A%0A    int version = (int) Double.parseDouble(System.getProperty(%22java.class.version%22));%0A    if (49 %3C= version && version %3C= 52) %7B%0A      return version - (49 - 5);%0A    %7D%0A    throw new IllegalStateException(%0A        %22Unknown Java version: %22 + System.getProperty(%22java.specification.version%22));%0A  %7D
+FEATURE = Runtime.version().feature();
 %0A%0A  
@@ -890,29 +890,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 8;%0A  %7D%0A%0A
@@ -1023,29 +1023,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 9;%0A  %7D%0A%0A
@@ -1158,29 +1158,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 10;%0A  %7D%0A
@@ -1299,21 +1299,23 @@
  return 
-MAJOR
+FEATURE
  %3C= 10;%0A
@@ -1431,29 +1431,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 11;%0A  %7D%0A
@@ -1567,29 +1567,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 12;%0A  %7D%0A
@@ -1703,29 +1703,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 13;%0A  %7D%0A
@@ -1839,29 +1839,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 14;%0A  %7D%0A
@@ -1975,29 +1975,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 15;%0A  %7D%0A
@@ -2111,29 +2111,31 @@
 %0A    return 
-MAJOR
+FEATURE
  %3E= 16;%0A  %7D%0A
@@ -2251,21 +2251,23 @@
  return 
-MAJOR
+FEATURE
  %3E= 17;%0A
@@ -2463,13 +2463,15 @@
 urn 
-MAJOR
+FEATURE
 ;%0A  

Remove a use of reflection now that we're only testing on JDK 11+