typetools · mernst · May 21, 2026 · May 19, 2026 · May 19, 2026 · May 19, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -51,6 +51,7 @@ jobs:
         run: make jdk
 
   build_jdk21u:
+    if: endsWith(github.repository, '/jdk')
     needs:
       - check_generated_ci
     runs-on: ubuntu-latest

diff --git a/.github/workflows/ci.yml.m4 b/.github/workflows/ci.yml.m4
@@ -55,6 +55,7 @@ jobs:
         run: make jdk
 
   build_jdk21u:
+    if: endsWith(github.repository, '/jdk')
     needs:
       - check_generated_ci
     runs-on: ubuntu-latest

diff --git a/src/java.base/share/classes/java/io/BufferedReader.java b/src/java.base/share/classes/java/io/BufferedReader.java
@@ -40,6 +40,7 @@
 import org.checkerframework.dataflow.qual.Pure;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
 import org.checkerframework.framework.qual.AnnotatedFor;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.util.Iterator;
 import java.util.NoSuchElementException;
@@ -510,8 +511,8 @@ private long implSkip(long n) throws IOException {
      *
      * @throws     IOException  If an I/O error occurs
      */
-    @EnsuresNonNullIf(expression={"readLine()"}, result=true)
     @Pure
+    @EnsuresNonNullIf(expression={"readLine()"}, result=true)
     public boolean ready(@GuardSatisfied BufferedReader this) throws IOException {
         Object lock = this.lock;
         if (lock instanceof InternalLock locker) {
@@ -709,6 +710,7 @@ public boolean hasNext() {
 
             @Override
             // @SideEffectsOnly("this")
+            @DoesNotUnrefineReceiver("modifiability")
             public String next(/*@NonEmpty Iterator<String> this*/) {
                 if (nextLine != null || hasNext()) {
                     String line = nextLine;

diff --git a/src/java.base/share/classes/java/lang/CharSequence.java b/src/java.base/share/classes/java/lang/CharSequence.java
@@ -36,6 +36,7 @@
 import org.checkerframework.dataflow.qual.SideEffectFree;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
 import org.checkerframework.framework.qual.AnnotatedFor;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.util.NoSuchElementException;
 import java.util.Objects;
@@ -175,6 +176,7 @@ public boolean hasNext() {
             }
 
             // @SideEffectsOnly("this")
+            @DoesNotUnrefineReceiver("modifiability")
             public int nextInt(@NonEmpty CharIterator this) {
                 if (hasNext()) {
                     return charAt(cur++);
@@ -252,6 +254,7 @@ public boolean hasNext() {
             }
 
             // @SideEffectsOnly("this")
+            @DoesNotUnrefineReceiver("modifiability")
             public int nextInt(@NonEmpty CodePointIterator this) {
                 final int length = length();
 

diff --git a/src/java.base/share/classes/java/lang/Class.java b/src/java.base/share/classes/java/lang/Class.java
@@ -840,8 +840,8 @@ public Void run() {
      *          {@code false} otherwise.
      * @since   1.1
      */
-    @EnsuresNonNullIf(expression={"getComponentType()"}, result=true)
     @Pure
+    @EnsuresNonNullIf(expression={"getComponentType()"}, result=true)
     @IntrinsicCandidate
     public native boolean isArray(@GuardSatisfied Class<T> this);
 

diff --git a/src/java.base/share/classes/java/lang/String.java b/src/java.base/share/classes/java/lang/String.java
@@ -1945,8 +1945,8 @@ public void getBytes(@IndexOrHigh({"this"}) int srcBegin, @IndexOrHigh({"this"})
      * @see  #compareTo(String)
      * @see  #equalsIgnoreCase(String)
      */
-    @EnsuresNonNullIf(expression={"#1"}, result=true)
     @Pure
+    @EnsuresNonNullIf(expression={"#1"}, result=true)
     @StaticallyExecutable
     public boolean equals(@GuardSatisfied @Nullable Object anObject) {
         if (this == anObject) {
@@ -2084,8 +2084,8 @@ public boolean contentEquals(@GuardSatisfied CharSequence cs) {
      * @see  #equals(Object)
      * @see  #codePoints()
      */
-    @EnsuresNonNullIf(expression={"#1"}, result=true)
     @Pure
+    @EnsuresNonNullIf(expression={"#1"}, result=true)
     @StaticallyExecutable
     public boolean equalsIgnoreCase(@Nullable String anotherString) {
         return (this == anotherString) ? true

diff --git a/src/java.base/share/classes/java/lang/invoke/AbstractConstantGroup.java b/src/java.base/share/classes/java/lang/invoke/AbstractConstantGroup.java
@@ -29,6 +29,7 @@
 import org.checkerframework.checker.nonempty.qual.NonEmpty;
 import org.checkerframework.dataflow.qual.Pure;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.util.*;
 import jdk.internal.vm.annotation.Stable;
@@ -101,6 +102,7 @@ public boolean hasNext() {
 
         @Override
         // @SideEffectsOnly("this")
+        @DoesNotUnrefineReceiver("modifiability")
         public Object next(@NonEmpty AsIterator this) {
             int i = bumpIndex();
             if (resolving)

diff --git a/src/java.base/share/classes/java/net/URL.java b/src/java.base/share/classes/java/net/URL.java
@@ -35,6 +35,7 @@
 import org.checkerframework.dataflow.qual.SideEffectFree;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
 import org.checkerframework.framework.qual.AnnotatedFor;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.io.File;
 import java.io.IOException;
@@ -1513,6 +1514,7 @@ public boolean hasNext() {
             }
 
             // @SideEffectsOnly("this")
+            @DoesNotUnrefineReceiver("modifiability")
             public URLStreamHandlerProvider next(/*@NonEmpty Iterator<URLStreamHandlerProvider> this*/) {
                 if (!getNext())
                     throw new NoSuchElementException();

diff --git a/src/java.base/share/classes/java/nio/charset/Charset.java b/src/java.base/share/classes/java/nio/charset/Charset.java
@@ -29,6 +29,7 @@
 import org.checkerframework.checker.nonempty.qual.NonEmpty;
 import org.checkerframework.dataflow.qual.Pure;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import jdk.internal.misc.ThreadTracker;
 import jdk.internal.misc.VM;
@@ -371,6 +372,7 @@ public boolean hasNext() {
                 }
 
                 // @SideEffectsOnly("this")
+                @DoesNotUnrefineReceiver("modifiability")
                 public CharsetProvider next(/*@NonEmpty Iterator<CharsetProvider> this*/) {
                     if (!getNext())
                         throw new NoSuchElementException();

diff --git a/src/java.base/share/classes/java/nio/file/FileTreeIterator.java b/src/java.base/share/classes/java/nio/file/FileTreeIterator.java
@@ -29,6 +29,7 @@
 import org.checkerframework.checker.nonempty.qual.NonEmpty;
 import org.checkerframework.dataflow.qual.Pure;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -113,6 +114,7 @@ public boolean hasNext() {
 
     @Override
     // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public Event next(@NonEmpty FileTreeIterator this) {
         if (!walker.isOpen())
             throw new IllegalStateException();

diff --git a/src/java.base/share/classes/java/nio/file/Files.java b/src/java.base/share/classes/java/nio/file/Files.java
@@ -30,12 +30,13 @@
 import org.checkerframework.checker.mustcall.qual.MustCall;
 import org.checkerframework.checker.nonempty.qual.EnsuresNonEmptyIf;
 import org.checkerframework.checker.nonempty.qual.NonEmpty;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.checkerframework.checker.signedness.qual.PolySigned;
 import org.checkerframework.dataflow.qual.Pure;
 import org.checkerframework.dataflow.qual.SideEffectFree;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
 import org.checkerframework.framework.qual.AnnotatedFor;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
@@ -3866,6 +3867,7 @@ public boolean hasNext() {
                     }
                 }
                 // @SideEffectsOnly("this")
+                @DoesNotUnrefineReceiver("modifiability")
                 @Override
                 public Path next(/*@NonEmpty Iterator<Path> this*/) {
                     try {

diff --git a/src/java.base/share/classes/java/nio/file/Path.java b/src/java.base/share/classes/java/nio/file/Path.java
@@ -32,6 +32,7 @@
 import org.checkerframework.dataflow.qual.SideEffectFree;
 // import org.checkerframework.dataflow.qual.SideEffectsOnly;
 import org.checkerframework.framework.qual.AnnotatedFor;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import java.io.File;
 import java.io.IOException;
@@ -963,6 +964,7 @@ public boolean hasNext() {
 
             @Override
             // @SideEffectsOnly("this")
+            @DoesNotUnrefineReceiver("modifiability")
             public Path next(/*@NonEmpty Iterator<Path> this*/) {
                 if (i < getNameCount()) {
                     Path result = getName(i);

diff --git a/src/java.base/share/classes/java/security/Provider.java b/src/java.base/share/classes/java/security/Provider.java
@@ -28,6 +28,7 @@
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.checkerframework.checker.nullness.qual.PolyNull;
 import org.checkerframework.checker.signedness.qual.UnknownSignedness;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import jdk.internal.event.SecurityProviderServiceEvent;
 
@@ -635,6 +636,7 @@ public synchronized Object replace(Object key, Object value) {
      * @since 1.8
      */
     @Override
+    @DoesNotUnrefineReceiver("modifiability")
     public synchronized void replaceAll(BiFunction<? super Object,
             ? super Object, ? extends Object> function) {
         check("putProviderProperty." + name);
@@ -663,6 +665,7 @@ public synchronized void replaceAll(BiFunction<? super Object,
      * @since 1.8
      */
     @Override
+    @DoesNotUnrefineReceiver("modifiability")
     public synchronized @PolyNull Object compute(Object key, BiFunction<? super Object,
             ? super Object, ? extends @PolyNull Object> remappingFunction) {
         check("putProviderProperty." + name);
@@ -693,6 +696,7 @@ public synchronized void replaceAll(BiFunction<? super Object,
      * @since 1.8
      */
     @Override
+    @DoesNotUnrefineReceiver("modifiability")
     public synchronized @PolyNull Object computeIfAbsent(Object key,
             Function<? super Object, ? extends @PolyNull Object> mappingFunction) {
         check("putProviderProperty." + name);
@@ -722,6 +726,7 @@ public synchronized void replaceAll(BiFunction<? super Object,
      * @since 1.8
      */
     @Override
+    @DoesNotUnrefineReceiver("modifiability")
     public synchronized @PolyNull Object computeIfPresent(Object key,
             BiFunction<? super Object, ? super Object, ? extends @PolyNull Object>
             remappingFunction) {
@@ -755,6 +760,7 @@ public synchronized void replaceAll(BiFunction<? super Object,
      * @since 1.8
      */
     @Override
+    @DoesNotUnrefineReceiver("modifiability")
     public synchronized @PolyNull Object merge(Object key, Object value,
             BiFunction<? super Object, ? super Object, ? extends @PolyNull Object>
             remappingFunction) {

diff --git a/src/java.base/share/classes/java/util/AbstractCollection.java b/src/java.base/share/classes/java/util/AbstractCollection.java
@@ -39,6 +39,7 @@
 import org.checkerframework.dataflow.qual.SideEffectFree;
 import org.checkerframework.framework.qual.AnnotatedFor;
 import org.checkerframework.framework.qual.CFComment;
+import org.checkerframework.framework.qual.DoesNotUnrefineReceiver;
 
 import jdk.internal.util.ArraysSupport;
 
@@ -275,6 +276,8 @@ private static <T> T[] finishToArray(T[] r, Iterator<?> it) {
      * @throws IllegalArgumentException      {@inheritDoc}
      * @throws IllegalStateException         {@inheritDoc}
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public boolean add(@GuardSatisfied AbstractCollection<E> this, E e) {
         throw new UnsupportedOperationException();
     }
@@ -296,6 +299,8 @@ public boolean add(@GuardSatisfied AbstractCollection<E> this, E e) {
      * @throws ClassCastException            {@inheritDoc}
      * @throws NullPointerException          {@inheritDoc}
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public boolean remove(@GuardSatisfied @CanShrink AbstractCollection<E> this, @GuardSatisfied @UnknownSignedness Object o) {
         Iterator<E> it = iterator();
         if (o==null) {
@@ -359,6 +364,8 @@ public boolean containsAll(@GuardSatisfied AbstractCollection<E> this, @GuardSat
      *
      * @see #add(Object)
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public boolean addAll(@GuardSatisfied AbstractCollection<E> this, Collection<? extends E> c) {
         boolean modified = false;
         for (E e : c)
@@ -389,6 +396,8 @@ public boolean addAll(@GuardSatisfied AbstractCollection<E> this, Collection<? e
      * @see #remove(Object)
      * @see #contains(Object)
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public boolean removeAll(@GuardSatisfied @CanShrink AbstractCollection<E> this, Collection<? extends @UnknownSignedness Object> c) {
         Objects.requireNonNull(c);
         boolean modified = false;
@@ -424,6 +433,8 @@ public boolean removeAll(@GuardSatisfied @CanShrink AbstractCollection<E> this,
      * @see #remove(Object)
      * @see #contains(Object)
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public boolean retainAll(@GuardSatisfied @CanShrink AbstractCollection<E> this, Collection<? extends @UnknownSignedness Object> c) {
         Objects.requireNonNull(c);
         boolean modified = false;
@@ -453,6 +464,8 @@ public boolean retainAll(@GuardSatisfied @CanShrink AbstractCollection<E> this,
      *
      * @throws UnsupportedOperationException {@inheritDoc}
      */
+    // @SideEffectsOnly("this")
+    @DoesNotUnrefineReceiver("modifiability")
     public void clear(@GuardSatisfied @CanShrink AbstractCollection<E> this) {
         Iterator<E> it = iterator();
         while (it.hasNext()) {