From 9257ba8af3e69fe30bcb9364167fabb738c70efb Mon Sep 17 00:00:00 2001
From: Marco Ferrari <ferrari.marco@gmail.com>
Date: Tue, 2 Jan 2024 18:47:45 +0100
Subject: [PATCH] build: use embedded checkstyle configuration files (#5089)

checkstyle embeds sun_checks.xml and google_checks.xml so we can use
them instead of shipping our own.
---
 README.md                                     |   2 +-
 TEMPLATES/sun_checks.xml                      | 201 ------------------
 lib/functions/linterRules.sh                  |  16 +-
 .../super-linter/controls/super_linter.rb     |   3 +-
 test/linters/java/java_good_2.java            |   5 +
 5 files changed, 21 insertions(+), 206 deletions(-)
 delete mode 100644 TEMPLATES/sun_checks.xml

diff --git a/README.md b/README.md
index 742da0a3..66a9d7d3 100644
--- a/README.md
+++ b/README.md
@@ -179,7 +179,7 @@ You can configure super-linter using the following environment variables:
 | **GITLEAKS_CONFIG_FILE**                        | `.gitleaks.toml`                | Filename for [GitLeaks configuration](https://github.com/zricethezav/gitleaks#configuration) (ex: `.gitleaks.toml`)                                                                                                  |
 | **IGNORE_GENERATED_FILES**                      | `false`                         | If set to `true`, super-linter will ignore all the files with `@generated` marker but without `@not-generated` marker.                                                                                               |
 | **IGNORE_GITIGNORED_FILES**                     | `false`                         | If set to `true`, super-linter will ignore all the files that are ignored by Git.                                                                                                                                    |
-| **JAVA_FILE_NAME**                              | `sun_checks.xml`                | Filename for [Checkstyle configuration](https://checkstyle.sourceforge.io/config.html) (ex: `checkstyle.xml`)                                                                                                        |
+| **JAVA_FILE_NAME**                              | `sun_checks.xml`                | Filename for [Checkstyle configuration](https://checkstyle.sourceforge.io/config.html). Checkstyle embeds several configuration files, such as `sun_checks.xml`, `google_checks.xml` that you can use without providing your own configuration file. |
 | **JAVASCRIPT_DEFAULT_STYLE**                    | `standard`                      | Flag to set the default style of JavaScript. Available options: **standard**/**prettier**                                                                                                                            |
 | **JAVASCRIPT_ES_CONFIG_FILE**                   | `.eslintrc.yml`                 | Filename for [ESLint configuration](https://eslint.org/docs/user-guide/configuring#configuration-file-formats) (ex: `.eslintrc.yml`, `.eslintrc.json`)                                                               |
 | **JSCPD_CONFIG_FILE**                           | `.jscpd.json`                   | Filename for JSCPD configuration                                                                                                                                                                                     |
diff --git a/TEMPLATES/sun_checks.xml b/TEMPLATES/sun_checks.xml
deleted file mode 100644
index 9b68056d..00000000
--- a/TEMPLATES/sun_checks.xml
+++ /dev/null
@@ -1,201 +0,0 @@
-<?xml version="1.0"?>
-<!DOCTYPE module PUBLIC
-          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
-          "https://checkstyle.org/dtds/configuration_1_3.dtd">
-
-<!--
-
-  Checkstyle configuration that checks the sun coding conventions from:
-
-    - the Java Language Specification at
-      https://docs.oracle.com/javase/specs/jls/se11/html/index.html
-
-    - the Sun Code Conventions at https://www.oracle.com/java/technologies/javase/codeconventions-contents.html
-
-    - the Javadoc guidelines at
-      https://www.oracle.com/technical-resources/articles/java/javadoc-tool.html
-
-    - the JDK Api documentation https://docs.oracle.com/en/java/javase/11/
-
-    - some best practices
-
-  Checkstyle is very configurable. Be sure to read the documentation at
-  https://checkstyle.org (or in your downloaded distribution).
-
-  Most Checks are configurable, be sure to consult the documentation.
-
-  To completely disable a check, just comment it out or delete it from the file.
-  To suppress certain violations please review suppression filters.
-
-  Finally, it is worth reading the documentation.
-
--->
-
-<module name="Checker">
-  <!--
-      If you set the basedir property below, then all reported file
-      names will be relative to the specified directory. See
-      https://checkstyle.org/config.html#Checker
-
-      <property name="basedir" value="${basedir}"/>
-  -->
-  <property name="severity" value="error"/>
-
-  <property name="fileExtensions" value="java, properties, xml"/>
-
-  <!-- Excludes all 'module-info.java' files              -->
-  <!-- See https://checkstyle.org/config_filefilters.html -->
-  <module name="BeforeExecutionExclusionFileFilter">
-    <property name="fileNamePattern" value="module\-info\.java$"/>
-  </module>
-
-  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
-  <module name="SuppressionFilter">
-    <property name="file" value="${org.checkstyle.sun.suppressionfilter.config}" default="checkstyle-suppressions.xml" />
-    <property name="optional" value="true"/>
-  </module>
-
-  <!-- Checks that a package-info.java file exists for each package.     -->
-  <!-- See https://checkstyle.org/config_javadoc.html#JavadocPackage -->
-  <module name="JavadocPackage"/>
-
-  <!-- Checks whether files end with a new line.                        -->
-  <!-- See https://checkstyle.org/config_misc.html#NewlineAtEndOfFile -->
-  <module name="NewlineAtEndOfFile"/>
-
-  <!-- Checks that property files contain the same keys.         -->
-  <!-- See https://checkstyle.org/config_misc.html#Translation -->
-  <module name="Translation"/>
-
-  <!-- Checks for Size Violations.                    -->
-  <!-- See https://checkstyle.org/config_sizes.html -->
-  <module name="FileLength"/>
-  <module name="LineLength">
-    <property name="fileExtensions" value="java"/>
-  </module>
-
-  <!-- Checks for whitespace                               -->
-  <!-- See https://checkstyle.org/config_whitespace.html -->
-  <module name="FileTabCharacter"/>
-
-  <!-- Miscellaneous other checks.                   -->
-  <!-- See https://checkstyle.org/config_misc.html -->
-  <module name="RegexpSingleline">
-    <property name="format" value="\s+$"/>
-    <property name="minimum" value="0"/>
-    <property name="maximum" value="0"/>
-    <property name="message" value="Line has trailing spaces."/>
-  </module>
-
-  <!-- Checks for Headers                                -->
-  <!-- See https://checkstyle.org/config_header.html   -->
-  <!-- <module name="Header"> -->
-  <!--   <property name="headerFile" value="${checkstyle.header.file}"/> -->
-  <!--   <property name="fileExtensions" value="java"/> -->
-  <!-- </module> -->
-
-  <!-- Enables @SuppressWarnings Support                -->
-  <module name="SuppressWarningsFilter"/>
-  <module name="TreeWalker">
-
-    <!-- Checks for Javadoc comments.                     -->
-    <!-- See https://checkstyle.org/config_javadoc.html -->
-    <module name="InvalidJavadocPosition"/>
-    <module name="JavadocMethod"/>
-    <module name="JavadocType"/>
-    <module name="JavadocVariable"/>
-    <module name="JavadocStyle"/>
-    <module name="MissingJavadocMethod"/>
-    <!-- Enables @SuppressWarnings Support                -->
-    <module name="SuppressWarningsHolder"/>
-
-    <!-- Checks for Naming Conventions.                  -->
-    <!-- See https://checkstyle.org/config_naming.html -->
-    <module name="ConstantName"/>
-    <module name="LocalFinalVariableName"/>
-    <module name="LocalVariableName"/>
-    <module name="MemberName"/>
-    <module name="MethodName"/>
-    <module name="PackageName"/>
-    <module name="ParameterName"/>
-    <module name="StaticVariableName"/>
-    <module name="TypeName"/>
-
-    <!-- Checks for imports                              -->
-    <!-- See https://checkstyle.org/config_imports.html -->
-    <module name="AvoidStarImport"/>
-    <module name="IllegalImport"/>
-    <!-- defaults to sun.* packages -->
-    <module name="RedundantImport"/>
-    <module name="UnusedImports">
-      <property name="processJavadoc" value="false"/>
-    </module>
-
-    <!-- Checks for Size Violations.                    -->
-    <!-- See https://checkstyle.org/config_sizes.html -->
-    <module name="MethodLength"/>
-    <module name="ParameterNumber"/>
-
-    <!-- Checks for whitespace                               -->
-    <!-- See https://checkstyle.org/config_whitespace.html -->
-    <module name="EmptyForIteratorPad"/>
-    <module name="GenericWhitespace"/>
-    <module name="MethodParamPad"/>
-    <module name="NoWhitespaceAfter"/>
-    <module name="NoWhitespaceBefore"/>
-    <module name="OperatorWrap"/>
-    <module name="ParenPad"/>
-    <module name="TypecastParenPad"/>
-    <module name="WhitespaceAfter"/>
-    <module name="WhitespaceAround"/>
-
-    <!-- Modifier Checks                                    -->
-    <!-- See https://checkstyle.org/config_modifiers.html -->
-    <module name="ModifierOrder"/>
-    <module name="RedundantModifier"/>
-
-    <!-- Checks for blocks. You know, those {}'s         -->
-    <!-- See https://checkstyle.org/config_blocks.html -->
-    <module name="AvoidNestedBlocks"/>
-    <module name="EmptyBlock"/>
-    <module name="LeftCurly"/>
-    <module name="NeedBraces"/>
-    <module name="RightCurly"/>
-
-    <!-- Checks for common coding problems               -->
-    <!-- See https://checkstyle.org/config_coding.html -->
-    <module name="EmptyStatement"/>
-    <module name="EqualsHashCode"/>
-    <module name="HiddenField"/>
-    <module name="IllegalInstantiation"/>
-    <module name="InnerAssignment"/>
-    <module name="MagicNumber"/>
-    <module name="MissingSwitchDefault"/>
-    <module name="MultipleVariableDeclarations"/>
-    <module name="SimplifyBooleanExpression"/>
-    <module name="SimplifyBooleanReturn"/>
-
-    <!-- Checks for class design                         -->
-    <!-- See https://checkstyle.org/config_design.html -->
-    <module name="DesignForExtension"/>
-    <module name="FinalClass"/>
-    <module name="HideUtilityClassConstructor"/>
-    <module name="InterfaceIsType"/>
-    <module name="VisibilityModifier"/>
-
-    <!-- Miscellaneous other checks.                   -->
-    <!-- See https://checkstyle.org/config_misc.html -->
-    <module name="ArrayTypeStyle"/>
-    <module name="FinalParameters"/>
-    <module name="TodoComment"/>
-    <module name="UpperEll"/>
-
-    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
-    <module name="SuppressionXpathFilter">
-      <property name="file" value="${org.checkstyle.sun.suppressionxpathfilter.config}" default="checkstyle-xpath-suppressions.xml" />
-      <property name="optional" value="true"/>
-    </module>
-
-  </module>
-
-</module>
diff --git a/lib/functions/linterRules.sh b/lib/functions/linterRules.sh
index 9bc1245f..ed99f17f 100755
--- a/lib/functions/linterRules.sh
+++ b/lib/functions/linterRules.sh
@@ -161,8 +161,20 @@ GetLinterRules() {
     # Found the rules file
     debug "  -> ${LANGUAGE_LINTER_RULES} rules file (${!LANGUAGE_LINTER_RULES}) exists."
   else
-    # Here we expect a rules file, so fail if not available.
-    fatal "  -> ${LANGUAGE_LINTER_RULES} rules file (${!LANGUAGE_LINTER_RULES}) doesn't exist. Terminating..."
+    local LANGUAGE_LINTER_RULES_BASENAME
+    LANGUAGE_LINTER_RULES_BASENAME="$(basename "${!LANGUAGE_LINTER_RULES}")"
+    debug "LANGUAGE_LINTER_RULES_BASENAME: ${LANGUAGE_LINTER_RULES_BASENAME}"
+    # checkstyle embeds some configuration files, such as google_checks.xml and sun_checks.xml.
+    # If we or the user specified one of those files and the file is missing, fall back to
+    # the embedded one.
+    if [[ "${LANGUAGE_NAME}" == "JAVA" && ("${LANGUAGE_LINTER_RULES_BASENAME}" == "google_checks.xml" || "${LANGUAGE_LINTER_RULES_BASENAME}" == "sun_checks.xml") ]]; then
+      debug "${!LANGUAGE_LINTER_RULES} for ${LANGUAGE_NAME} doesn't exist. Falling back to ${LANGUAGE_LINTER_RULES_BASENAME} that the linter ships."
+      eval "${LANGUAGE_LINTER_RULES}=/${LANGUAGE_LINTER_RULES_BASENAME}"
+      debug "Updated ${LANGUAGE_LINTER_RULES}: ${!LANGUAGE_LINTER_RULES}"
+    else
+      # Here we expect a rules file, so fail if not available.
+      fatal "  -> ${LANGUAGE_LINTER_RULES} rules file (${!LANGUAGE_LINTER_RULES}) doesn't exist. Terminating..."
+    fi
   fi
 
   ######################
diff --git a/test/inspec/super-linter/controls/super_linter.rb b/test/inspec/super-linter/controls/super_linter.rb
index 1e248ba9..118efe7c 100644
--- a/test/inspec/super-linter/controls/super_linter.rb
+++ b/test/inspec/super-linter/controls/super_linter.rb
@@ -484,8 +484,7 @@ control "super-linter-validate-files" do
     "/action/lib/.automation/.yaml-lint.yml",
     "/action/lib/.automation/phpcs.xml",
     "/action/lib/.automation/phpstan.neon",
-    "/action/lib/.automation/psalm.xml",
-    "/action/lib/.automation/sun_checks.xml"
+    "/action/lib/.automation/psalm.xml"
   ]
 
   files.each do |item|
diff --git a/test/linters/java/java_good_2.java b/test/linters/java/java_good_2.java
index 376cef1f..95142512 100644
--- a/test/linters/java/java_good_2.java
+++ b/test/linters/java/java_good_2.java
@@ -1,6 +1,11 @@
 @SuppressWarnings("checkstyle:hideutilityclassconstructor")
 public class Application {
 
+  protected StringUtils() {
+    // prevents calls from subclass
+    throw new UnsupportedOperationException();
+  }
+
   /**
    * main.
    *