Migrate Error Prone to use JSpecify nullness annotations

PiperOrigin-RevId: 655693769

check_api/pom.xml

@@ -44,10 +44,10 @@
       <version>${project.version}</version>
     </dependency>
     <dependency>
-      <!-- BSD New -->
-      <groupId>com.google.code.findbugs</groupId>
-      <artifactId>jsr305</artifactId>
-      <version>3.0.2</version>
+      <!-- Apache 2.0 -->
+      <groupId>org.jspecify</groupId>
+      <artifactId>jspecify</artifactId>
+      <version>${jspecify.version}</version>
     </dependency>
     <dependency>
       <!-- GPLv2 with Classpath Exception -->

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

@@ -34,14 +34,14 @@
 import java.util.Locale;
 import java.util.ResourceBundle;
 import java.util.Set;
-import javax.annotation.Nullable;
 import javax.lang.model.SourceVersion;
 import javax.tools.DiagnosticListener;
 import javax.tools.JavaCompiler;
 import javax.tools.JavaCompiler.CompilationTask;
 import javax.tools.JavaFileManager;
 import javax.tools.JavaFileObject;
 import javax.tools.StandardJavaFileManager;
+import org.jspecify.annotations.Nullable;
 
 /** An Error Prone compiler that implements {@link javax.tools.JavaCompiler}. */
 public class BaseErrorProneJavaCompiler implements JavaCompiler {

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

@@ -29,7 +29,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * An accessor for information about a single bug checker, including the metadata in the check's
@@ -172,8 +172,7 @@ public BugCheckerInfo withCustomDefaultSeverity(SeverityLevel defaultSeverity) {
         disableable);
   }
 
-  @Nullable
-  private static String createLinkUrl(String canonicalName, BugPattern pattern) {
+  private static @Nullable String createLinkUrl(String canonicalName, BugPattern pattern) {
     switch (pattern.linkType()) {
       case AUTOGENERATED:
         return String.format("https://errorprone.info/bugpattern/%s", canonicalName);

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

@@ -60,8 +60,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import javax.annotation.Nullable;
 import javax.lang.model.util.Elements;
+import org.jspecify.annotations.Nullable;
 
 /**
  * @author [email protected] (Alex Eagle)
@@ -355,16 +355,14 @@ public Name getName(String nameStr) {
    * @param typeStr the JLS 13.1 binary name of the class, e.g. {@code "java.util.Map$Entry"}
    * @return the {@link Type}, or null if it cannot be found
    */
-  @Nullable
-  public Type getTypeFromString(String typeStr) {
+  public @Nullable Type getTypeFromString(String typeStr) {
     return sharedState
         .typeCache
         .computeIfAbsent(typeStr, key -> Optional.ofNullable(getTypeFromStringInternal(key)))
         .orElse(null);
   }
 
-  @Nullable
-  private Type getTypeFromStringInternal(String typeStr) {
+  private @Nullable Type getTypeFromStringInternal(String typeStr) {
     validateTypeStr(typeStr);
     Type primitiveOrVoidType = getPrimitiveOrVoidType(typeStr);
     if (primitiveOrVoidType != null) {
@@ -385,8 +383,7 @@ private Type getTypeFromStringInternal(String typeStr) {
    * @return the Symbol object, or null if it cannot be found
    */
   // TODO(cushon): deal with binary compat issues and return ClassSymbol
-  @Nullable
-  public Symbol getSymbolFromString(String symStr) {
+  public @Nullable Symbol getSymbolFromString(String symStr) {
     return getSymbolFromName(binaryNameFromClassname(symStr));
   }
 
@@ -404,8 +401,7 @@ public Name binaryNameFromClassname(String className) {
    *
    * @param name the name to look up, which must be in binary form (i.e. with $ for nested classes).
    */
-  @Nullable
-  public ClassSymbol getSymbolFromName(Name name) {
+  public @Nullable ClassSymbol getSymbolFromName(Name name) {
     boolean modular = sharedState.modules.getDefaultModule() != getSymtab().noModule;
     if (!modular) {
       return getSymbolFromString(getSymtab().noModule, name);
@@ -422,8 +418,7 @@ public ClassSymbol getSymbolFromName(Name name) {
     return null;
   }
 
-  @Nullable
-  public ClassSymbol getSymbolFromString(ModuleSymbol msym, Name name) {
+  public @Nullable ClassSymbol getSymbolFromString(ModuleSymbol msym, Name name) {
     ClassSymbol result = getSymtab().getClass(msym, name);
     if (result == null || result.kind == Kind.ERR || !result.exists()) {
       return null;
@@ -507,9 +502,8 @@ public Type arrayTypeForType(Type baseType) {
    *
    * @return the path, or {@code null} if there is no match
    */
-  @Nullable
   @SafeVarargs
-  public final TreePath findPathToEnclosing(Class<? extends Tree>... classes) {
+  public final @Nullable TreePath findPathToEnclosing(Class<? extends Tree>... classes) {
     TreePath enclosingPath = getPath();
     while (enclosingPath != null) {
       for (Class<? extends Tree> clazz : classes) {
@@ -527,10 +521,10 @@ public final TreePath findPathToEnclosing(Class<? extends Tree>... classes) {
    *
    * @return the node, or {@code null} if there is no match
    */
-  @Nullable
-  @SuppressWarnings("unchecked") // findPathToEnclosing guarantees that the type is from |classes|
+  // findPathToEnclosing guarantees that the type is from |classes|
+  @SuppressWarnings("unchecked")
   @SafeVarargs
-  public final <T extends Tree> T findEnclosing(Class<? extends T>... classes) {
+  public final <T extends Tree> @Nullable T findEnclosing(Class<? extends T>... classes) {
     TreePath pathToEnclosing = findPathToEnclosing(classes);
     return (pathToEnclosing == null) ? null : (T) pathToEnclosing.getLeaf();
   }
@@ -540,8 +534,7 @@ public final <T extends Tree> T findEnclosing(Class<? extends T>... classes) {
    *
    * @return the source file as a sequence of characters, or null if it is not available
    */
-  @Nullable
-  public CharSequence getSourceCode() {
+  public @Nullable CharSequence getSourceCode() {
     try {
       return getPath().getCompilationUnit().getSourceFile().getCharContent(false);
     } catch (IOException e) {
@@ -559,8 +552,7 @@ public CharSequence getSourceCode() {
    * @return the source code that represents the node, or {@code null} if the source code is
    *     unavailable (e.g. for generated or desugared AST nodes)
    */
-  @Nullable
-  public String getSourceForNode(Tree tree) {
+  public @Nullable String getSourceForNode(Tree tree) {
     int start = ((JCTree) tree).getStartPosition();
     int end = getEndPosition(tree);
     CharSequence source = getSourceCode();
@@ -634,8 +626,7 @@ private static void validateTypeStr(String typeStr) {
    * Given a string that represents a type, if it's a primitive type (e.g., "int") or "void", return
    * the corresponding Type, or null otherwise.
    */
-  @Nullable
-  private Type getPrimitiveOrVoidType(String typeStr) {
+  private @Nullable Type getPrimitiveOrVoidType(String typeStr) {
     switch (typeStr) {
       case "byte":
         return getSymtab().byteType;

check_api/src/main/java/com/google/errorprone/apply/DiffApplier.java

@@ -30,7 +30,7 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Applier of diffs to Java source code
@@ -132,8 +132,7 @@ public void run() {
     }
   }
 
-  @Nullable
-  public Future<?> put(Diff diff) {
+  public @Nullable Future<?> put(Diff diff) {
     if (refactoredPaths.add(diff.getRelevantFileName())) {
       runState.incrementAndGet();
       return workerService.submit(new Task(diff));

check_api/src/main/java/com/google/errorprone/apply/DiffSupplier.java

@@ -17,7 +17,7 @@
 package com.google.errorprone.apply;
 
 import java.io.IOException;
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Supplier of file differences.

check_api/src/main/java/com/google/errorprone/dataflow/AccessPath.java

@@ -28,7 +28,6 @@
 import com.sun.tools.javac.tree.JCTree.JCFieldAccess;
 import com.sun.tools.javac.tree.JCTree.JCIdent;
 import com.sun.tools.javac.tree.JCTree.JCMethodInvocation;
-import javax.annotation.Nullable;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
 import javax.lang.model.element.Modifier;
@@ -38,6 +37,7 @@
 import org.checkerframework.errorprone.dataflow.cfg.node.Node;
 import org.checkerframework.errorprone.dataflow.cfg.node.VariableDeclarationNode;
 import org.checkerframework.errorprone.javacutil.TreeUtils;
+import org.jspecify.annotations.Nullable;
 
 /**
  * A sequence of field names or autovalue accessors, along with a receiver: either a variable or a
@@ -61,8 +61,7 @@
 public abstract class AccessPath {
 
   /** If present, base of access path is contained Element; if absent, base is `this` */
-  @Nullable
-  public abstract Element base();
+  public abstract @Nullable Element base();
 
   public abstract ImmutableList<String> path();
 
@@ -111,8 +110,7 @@ public static boolean isAutoValueAccessor(Tree tree) {
    * otherwise (for example, when the receiver of the field access contains an array access or
    * non-AutoValue method call.
    */
-  @Nullable
-  public static AccessPath fromFieldAccess(FieldAccessNode fieldAccess) {
+  public static @Nullable AccessPath fromFieldAccess(FieldAccessNode fieldAccess) {
     ImmutableList.Builder<String> pathBuilder = ImmutableList.builder();
 
     Tree tree = fieldAccess.getTree();
@@ -161,8 +159,7 @@ public static AccessPath fromVariableDecl(VariableDeclarationNode node) {
    * Returns an AccessPath representing {@code node} if {@code node} is representable as an access
    * path and null otherwise
    */
-  @Nullable
-  public static AccessPath fromNodeIfTrackable(Node node) {
+  public static @Nullable AccessPath fromNodeIfTrackable(Node node) {
     if (node instanceof LocalVariableNode) {
       return fromLocalVariable((LocalVariableNode) node);
     } else if (node instanceof VariableDeclarationNode) {

check_api/src/main/java/com/google/errorprone/dataflow/AccessPathStore.java

@@ -24,11 +24,11 @@
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.LinkedHashMap;
 import java.util.Map;
-import javax.annotation.Nullable;
 import org.checkerframework.errorprone.dataflow.analysis.AbstractValue;
 import org.checkerframework.errorprone.dataflow.analysis.Store;
 import org.checkerframework.errorprone.dataflow.cfg.visualize.CFGVisualizer;
 import org.checkerframework.errorprone.dataflow.expression.JavaExpression;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Immutable map from local variables or heap access paths to their {@link AbstractValue}
@@ -58,8 +58,7 @@ public static <V extends AbstractValue<V>> AccessPathStore<V> empty() {
     return (AccessPathStore<V>) EMPTY;
   }
 
-  @Nullable
-  private V getInformation(AccessPath ap) {
+  private @Nullable V getInformation(AccessPath ap) {
     return heap().get(checkNotNull(ap));
   }
 

check_api/src/main/java/com/google/errorprone/dataflow/ConstantPropagationAnalysis.java

@@ -18,9 +18,9 @@
 
 import com.sun.source.util.TreePath;
 import com.sun.tools.javac.util.Context;
-import javax.annotation.Nullable;
 import org.checkerframework.errorprone.dataflow.constantpropagation.Constant;
 import org.checkerframework.errorprone.dataflow.constantpropagation.ConstantPropagationTransfer;
+import org.jspecify.annotations.Nullable;
 
 /** An interface to the constant propagation analysis. */
 public final class ConstantPropagationAnalysis {
@@ -33,8 +33,7 @@ public final class ConstantPropagationAnalysis {
    * evaluates to the same numeric value), and null otherwise. Note that returning null does not
    * necessarily mean the expression is *not* a constant.
    */
-  @Nullable
-  public static Number numberValue(TreePath exprPath, Context context) {
+  public static @Nullable Number numberValue(TreePath exprPath, Context context) {
     Constant val = DataFlow.expressionDataflow(exprPath, context, CONSTANT_PROPAGATION);
     if (val == null || !val.isConstant()) {
       return null;

check_api/src/main/java/com/google/errorprone/dataflow/DataFlow.java

@@ -32,7 +32,6 @@
 import com.sun.source.util.TreePath;
 import com.sun.tools.javac.processing.JavacProcessingEnvironment;
 import com.sun.tools.javac.util.Context;
-import javax.annotation.Nullable;
 import javax.annotation.processing.ProcessingEnvironment;
 import org.checkerframework.errorprone.dataflow.analysis.AbstractValue;
 import org.checkerframework.errorprone.dataflow.analysis.Analysis;
@@ -43,6 +42,7 @@
 import org.checkerframework.errorprone.dataflow.cfg.ControlFlowGraph;
 import org.checkerframework.errorprone.dataflow.cfg.UnderlyingAST;
 import org.checkerframework.errorprone.dataflow.cfg.builder.CFGBuilder;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Provides a wrapper around {@link org.checkerframework.errorprone.dataflow.analysis.Analysis}.
@@ -127,8 +127,7 @@ public ControlFlowGraph load(CfgParams key) {
               });
 
   // TODO(b/158869538): remove once we merge jdk8 specific's with core
-  @Nullable
-  private static <T> TreePath findEnclosingMethodOrLambdaOrInitializer(TreePath path) {
+  private static <T> @Nullable TreePath findEnclosingMethodOrLambdaOrInitializer(TreePath path) {
     while (path != null) {
       if (path.getLeaf() instanceof MethodTree) {
         return path;
@@ -201,10 +200,9 @@ public ControlFlowGraph getControlFlowGraph() {
    * @return dataflow result for the given expression or {@code null} if the expression is not part
    *     of a method, lambda or initializer
    */
-  @Nullable
   public static <
           A extends AbstractValue<A>, S extends Store<S>, T extends ForwardTransferFunction<A, S>>
-      A expressionDataflow(TreePath exprPath, Context context, T transfer) {
+      @Nullable A expressionDataflow(TreePath exprPath, Context context, T transfer) {
     Tree leaf = exprPath.getLeaf();
     Preconditions.checkArgument(
         leaf instanceof ExpressionTree,

check_api/src/main/java/com/google/errorprone/dataflow/nullnesspropagation/NullnessAnnotations.java

@@ -32,7 +32,6 @@
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
-import javax.annotation.Nullable;
 import javax.lang.model.element.AnnotationMirror;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
@@ -43,6 +42,7 @@
 import javax.lang.model.type.IntersectionType;
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.type.TypeVariable;
+import org.jspecify.annotations.Nullable;
 
 /** Utilities to extract {@link Nullness} from annotations. */
 public class NullnessAnnotations {