Support JDK 23+

Author: Stephan202

check_api/pom.xml

@@ -181,6 +181,22 @@
               </jdkToolchain>
             </configuration>
           </execution>
+          <execution>
+            <id>java23</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <jdkToolchain>
+                <version>23</version>
+              </jdkToolchain>
+              <compileSourceRoots>
+                <compileSourceRoot>${basedir}/src/main/java23</compileSourceRoot>
+              </compileSourceRoots>
+              <!-- multiReleaseOutput requires setting release -->
+              <outputDirectory>${project.build.outputDirectory}/META-INF/versions/23</outputDirectory>
+            </configuration>
+          </execution>
           <execution>
             <id>java24</id>
             <configuration>
@@ -197,6 +213,17 @@
         </executions>
 
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+        <configuration>
+          <archive>
+            <manifestEntries>
+              <Multi-Release>true</Multi-Release>
+            </manifestEntries>
+          </archive>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 

check_api/src/main/java/com/google/errorprone/ConstantStringExpressions.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2024 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;
+
+import com.sun.tools.javac.util.Convert;
+
+/**
+ * @see VisitorState#getConstantExpression(Object)
+ */
+final class ConstantStringExpressions {
+  private ConstantStringExpressions() {}
+
+  static String toConstantStringExpression(Object value, VisitorState state) {
+    if (!(value instanceof CharSequence)) {
+      return state.getElements().getConstantExpression(value);
+    }
+
+    // Don't escape single-quotes in string literals.
+    CharSequence str = (CharSequence) value;
+    StringBuilder sb = new StringBuilder("\"");
+    for (int i = 0; i < str.length(); i++) {
+      char c = str.charAt(i);
+      if (c == '\'') {
+        sb.append('\'');
+      } else {
+        sb.append(Convert.quote(c));
+      }
+    }
+    return sb.append('"').toString();
+  }
+}

check_api/src/main/java/com/google/errorprone/VisitorState.java

@@ -18,6 +18,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.errorprone.ConstantStringExpressions.toConstantStringExpression;
 import static com.google.errorprone.util.ASTHelpers.getStartPosition;
 
 import com.google.common.annotations.VisibleForTesting;
@@ -51,7 +52,6 @@
 import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
 import com.sun.tools.javac.tree.TreeMaker;
 import com.sun.tools.javac.util.Context;
-import com.sun.tools.javac.util.Convert;
 import com.sun.tools.javac.util.Name;
 import com.sun.tools.javac.util.Names;
 import com.sun.tools.javac.util.Options;
@@ -758,23 +758,10 @@ private static final class SharedState {
 
   /**
    * Returns the Java source code for a constant expression representing the given constant value.
-   * Like {@link Elements#getConstantExpression}, but doesn't over-escape single quotes in strings.
+   * Like {@link Elements#getConstantExpression}, but (a) before JDK 23, doesn't over-escape single
+   * quotes in strings and (b) treats any {@link CharSequence} as a {@link String}.
    */
   public String getConstantExpression(Object value) {
-    if (!(value instanceof CharSequence str)) {
-      return getElements().getConstantExpression(value);
-    }
-
-    // Don't escape single-quotes in string literals.
-    StringBuilder sb = new StringBuilder("\"");
-    for (int i = 0; i < str.length(); i++) {
-      char c = str.charAt(i);
-      if (c == '\'') {
-        sb.append('\'');
-      } else {
-        sb.append(Convert.quote(c));
-      }
-    }
-    return sb.append('"').toString();
+    return toConstantStringExpression(value, this);
   }
 }

check_api/src/main/java23/com/google/errorprone/ConstantStringExpressions.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2024 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;
+
+import com.google.errorprone.VisitorState;
+import com.sun.tools.javac.util.Convert;
+
+/**
+ * @see VisitorState#getConstantExpression(Object)
+ */
+final class ConstantStringExpressions {
+  private ConstantStringExpressions() {}
+
+  static String toConstantStringExpression(Object value, VisitorState state) {
+    return state
+        .getElements()
+        .getConstantExpression(
+            value instanceof CharSequence charSequence ? charSequence.toString() : value);
+  }
+}