8244146: javac changes for JEP 306

8266399: Core libs update for JEP 306

Reviewed-by: sadayapalam, bpb, naoto

src/java.base/share/classes/java/lang/FdLibm.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -120,7 +120,7 @@ class FdLibm {
             throw new UnsupportedOperationException();
         }
 
-        public static strictfp double compute(double x) {
+        public static double compute(double x) {
             double  t = 0.0;
             double sign;
 
@@ -203,7 +203,7 @@ class FdLibm {
             throw new UnsupportedOperationException();
         }
 
-        public static strictfp double compute(double x, double y) {
+        public static double compute(double x, double y) {
             double a = Math.abs(x);
             double b = Math.abs(y);
 
@@ -343,7 +343,7 @@ class FdLibm {
             throw new UnsupportedOperationException();
         }
 
-        public static strictfp double compute(final double x, final double y) {
+        public static double compute(final double x, final double y) {
             double z;
             double r, s, t, u, v, w;
             int i, j, k, n;
@@ -680,8 +680,7 @@ class FdLibm {
             throw new UnsupportedOperationException();
         }
 
-        // should be able to forgo strictfp due to controlled over/underflow
+        public static double compute(double x) {
-        public static strictfp double compute(double x) {
             double y;
             double hi = 0.0;
             double lo = 0.0;

src/java.base/share/classes/java/lang/StrictMath.java

@@ -86,7 +86,6 @@ import jdk.internal.vm.annotation.IntrinsicCandidate;
  * @author  Joseph D. Darcy
  * @since   1.3
  */
-
 public final class StrictMath {
 
     /**
@@ -207,10 +206,8 @@ public final class StrictMath {
      * @return  the measurement of the angle {@code angdeg}
      *          in radians.
      */
-    public static strictfp double toRadians(double angdeg) {
+    public static double toRadians(double angdeg) {
-        // Do not delegate to Math.toRadians(angdeg) because
+        return Math.toRadians(angdeg);
-        // this method has the strictfp modifier.
-        return angdeg * DEGREES_TO_RADIANS;
     }
 
     /**
@@ -224,10 +221,8 @@ public final class StrictMath {
      * @return  the measurement of the angle {@code angrad}
      *          in degrees.
      */
-    public static strictfp double toDegrees(double angrad) {
+    public static double toDegrees(double angrad) {
-        // Do not delegate to Math.toDegrees(angrad) because
+        return Math.toDegrees(angrad);
-        // this method has the strictfp modifier.
-        return angrad * RADIANS_TO_DEGREES;
     }
 
     /**

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -118,6 +118,9 @@ public class Lint
             if (source.compareTo(Source.JDK9) >= 0) {
                 values.add(LintCategory.DEP_ANN);
             }
+            if (Source.Feature.REDUNDANT_STRICTFP.allowedInSource(source)) {
+                values.add(LintCategory.STRICTFP);
+            }
             values.add(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC);
             values.add(LintCategory.OPENS);
             values.add(LintCategory.MODULE);
@@ -283,6 +286,11 @@ public class Lint
          */
         STATIC("static"),
 
+        /**
+         * Warn about unnecessary uses of the strictfp modifier
+         */
+        STRICTFP("strictfp"),
+
         /**
          * Warn about synchronization attempts on instances of @ValueBased classes.
          */

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -224,6 +224,7 @@ public enum Source {
         REIFIABLE_TYPES_INSTANCEOF(JDK16, Fragments.FeatureReifiableTypesInstanceof, DiagKind.PLURAL),
         RECORDS(JDK16, Fragments.FeatureRecords, DiagKind.PLURAL),
         SEALED_CLASSES(JDK17, Fragments.FeatureSealedClasses, DiagKind.PLURAL),
+        REDUNDANT_STRICTFP(JDK17),
         ;
 
         enum DiagKind {

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java

@@ -1211,6 +1211,9 @@ public class Check {
             } else {
                 mask = MethodFlags;
             }
+            if ((flags & STRICTFP) != 0) {
+                warnOnExplicitStrictfp(pos);
+            }
             // Imply STRICTFP if owner has STRICTFP set.
             if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
                 ((flags) & Flags.DEFAULT) != 0)
@@ -1252,6 +1255,9 @@ public class Check {
                 mask &= ~ABSTRACT;
                 implicit |= FINAL;
             }
+            if ((flags & STRICTFP) != 0) {
+                warnOnExplicitStrictfp(pos);
+            }
             // Imply STRICTFP if owner has STRICTFP set.
             implicit |= sym.owner.flags_field & STRICTFP;
             break;
@@ -1314,6 +1320,19 @@ public class Check {
         return flags & (mask | ~ExtendedStandardFlags) | implicit;
     }
 
+    private void warnOnExplicitStrictfp(DiagnosticPosition pos) {
+        DiagnosticPosition prevLintPos = deferredLintHandler.setPos(pos);
+        try {
+            deferredLintHandler.report(() -> {
+                                           if (lint.isEnabled(LintCategory.STRICTFP)) {
+                                               log.warning(LintCategory.STRICTFP,
+                                                           pos, Warnings.Strictfp); }
+                                       });
+        } finally {
+            deferredLintHandler.setPos(prevLintPos);
+        }
+    }
+
 
     /** Determine if this enum should be implicitly final.
      *

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/ConstFold.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -41,6 +41,7 @@ import static com.sun.tools.javac.jvm.ByteCodes.*;
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
+@SuppressWarnings("strictfp")
 strictfp class ConstFold {
     protected static final Context.Key<ConstFold> constFoldKey = new Context.Key<>();
 

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassWriter.java

@@ -40,6 +40,7 @@ import javax.tools.JavaFileObject;
 import com.sun.tools.javac.code.*;
 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
 import com.sun.tools.javac.code.Directive.*;
+import com.sun.tools.javac.code.Source.Feature;
 import com.sun.tools.javac.code.Symbol.*;
 import com.sun.tools.javac.code.Type.*;
 import com.sun.tools.javac.code.Types.SignatureGenerator.InvalidSignatureException;
@@ -1697,6 +1698,10 @@ public class ClassWriter extends ClassFile {
     int adjustFlags(final long flags) {
         int result = (int)flags;
 
+        // Elide strictfp bit in class files
+        if (target.obsoleteAccStrict())
+            result &= ~STRICTFP;
+
         if ((flags & BRIDGE) != 0)
             result |= ACC_BRIDGE;
         if ((flags & VARARGS) != 0)

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Target.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -194,4 +194,10 @@ public enum Target {
     public boolean hasSealedClasses() {
         return compareTo(JDK1_15) >= 0;
     }
+
+    /** Is the ACC_STRICT bit redundant and obsolete
+     */
+    public boolean obsoleteAccStrict() {
+        return compareTo(JDK1_17) >= 0;
+    }
 }

src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties

@@ -564,10 +564,10 @@ compiler.err.foreach.not.applicable.to.type=\
     found:    {0}
 
 compiler.err.fp.number.too.large=\
-    floating point number too large
+    floating-point number too large
 
 compiler.err.fp.number.too.small=\
-    floating point number too small
+    floating-point number too small
 
 compiler.err.generic.array.creation=\
     generic array creation
@@ -785,7 +785,7 @@ compiler.err.limit.string.overflow=\
     UTF8 representation for string \"{0}...\" is too long for the constant pool
 
 compiler.err.malformed.fp.lit=\
-    malformed floating point literal
+    malformed floating-point literal
 
 compiler.err.method.does.not.override.superclass=\
     method does not override or implement a method from a supertype
@@ -1764,6 +1764,9 @@ compiler.warn.dir.path.element.not.directory=\
 compiler.warn.missing-explicit-ctor=\
     class {0} in exported package {1} declares no explicit constructors, thereby exposing a default constructor to clients of module {2}
 
+compiler.warn.strictfp=\
+    as of release 17, all floating-point expressions are evaluated strictly and ''strictfp'' is not required
+
 compiler.warn.finally.cannot.complete=\
     finally clause cannot complete normally
 

src/jdk.compiler/share/classes/com/sun/tools/javac/resources/javac.properties

@@ -246,6 +246,9 @@ javac.opt.Xlint.desc.serial=\
 javac.opt.Xlint.desc.static=\
     Warn about accessing a static member using an instance.
 
+javac.opt.Xlint.desc.strictfp=\
+    Warn about unnecessary use of the strictfp modifier.
+
 javac.opt.Xlint.desc.text-blocks=\
     Warn about inconsistent white space characters in text block indentation.
 

src/jdk.jshell/share/classes/jdk/jshell/TaskFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -167,7 +167,7 @@ class TaskFactory {
         List<String> allOptions = new ArrayList<>();
 
         allOptions.add("--should-stop=at=FLOW");
-        allOptions.add("-Xlint:unchecked");
+        allOptions.add("-Xlint:unchecked,-strictfp");
         allOptions.add("-proc:none");
         allOptions.addAll(extraArgs);
 
@@ -184,7 +184,7 @@ class TaskFactory {
 
         return runTask(wraps.stream(),
                        sh,
-                       List.of("-Xlint:unchecked", "-proc:none", "-parameters"),
+                       List.of("-Xlint:unchecked,-strictfp", "-proc:none", "-parameters"),
                        (jti, diagnostics) -> new CompileTask(sh, jti, diagnostics),
                        worker);
     }

test/jdk/java/lang/reflect/Method/GenericStringTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -179,10 +179,10 @@ interface TestInterface1 {
     default <A> A bar(){return null;}
 
     @ExpectedString(
-   "public default strictfp double TestInterface1.quux()")
+   "public default double TestInterface1.quux()")
     @ExpectedGenericString(
-    "public default strictfp double TestInterface1.quux()")
+    "public default double TestInterface1.quux()")
-    strictfp default double quux(){return 1.0;}
+    default double quux(){return 1.0;}
 }
 
 @Retention(RetentionPolicy.RUNTIME)

test/langtools/tools/javac/7166455/CheckACC_STRICTFlagOnclinitTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,6 +26,7 @@
  * @bug 7166455
  * @summary javac doesn't set ACC_STRICT bit on <clinit> for strictfp class
  * @modules jdk.jdeps/com.sun.tools.classfile
+ * @compile -source 16 -target 16 CheckACC_STRICTFlagOnclinitTest.java
  * @run main CheckACC_STRICTFlagOnclinitTest
  */
 

test/langtools/tools/javac/8005931/CheckACC_STRICTFlagOnPkgAccessClassTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -81,7 +81,8 @@ public class CheckACC_STRICTFlagOnPkgAccessClassTest {
     }
 
     private void compile(JavaCompiler comp) {
-        JavacTask ct = (JavacTask)comp.getTask(null, null, null, null, null,
+        JavacTask ct = (JavacTask)comp.getTask(null, null, null,
+                                               List.of("--release", "16"), null,
                 Arrays.asList(source));
         try {
             if (!ct.call()) {

test/langtools/tools/javac/FloatingPointChanges/BadConstructorModifiers.java

@@ -1,10 +1,11 @@
 /*
  * @test  /nodynamiccopyright/
- * @bug 4153038 4785453
+ * @bug 4153038 4785453 8244146
  * @summary strictfp may not be used with constructors
  * @author David Stoutamire (dps)
  *
- * @compile/fail/ref=BadConstructorModifiers.out -XDrawDiagnostics BadConstructorModifiers.java
+ * @compile/fail/ref=BadConstructorModifiers.out -XDrawDiagnostics --release 16     BadConstructorModifiers.java
+ * @compile/fail/ref=BadConstructorModifiers.out -XDrawDiagnostics -Xlint:-strictfp BadConstructorModifiers.java
  */
 
 public class BadConstructorModifiers {

test/langtools/tools/javac/FloatingPointChanges/BadConstructorModifiers.out

@@ -1,2 +1,2 @@
-BadConstructorModifiers.java:12:14: compiler.err.mod.not.allowed.here: strictfp
+BadConstructorModifiers.java:13:14: compiler.err.mod.not.allowed.here: strictfp
 1 error

test/langtools/tools/javac/T6397044.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,7 +49,7 @@ public abstract class T6397044 {
         try (StandardJavaFileManager fm = tool.getStandardFileManager(null, null, null)) {
             Iterable<? extends JavaFileObject> files
                 = fm.getJavaFileObjectsFromFiles(Arrays.asList(new File(srcDir, self + ".java")));
-            JavacTask task = tool.getTask(null, fm, null, null, null, files);
+            JavacTask task = tool.getTask(null, fm, null, List.of("--release", "16"), null, files);
             Iterable<? extends CompilationUnitTree> trees = task.parse();
             Checker checker = new Checker();
             for (CompilationUnitTree tree: trees)

test/langtools/tools/javac/annotations/AnnotationTypeElementModifiers.java

@@ -1,8 +1,9 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8028428
+ * @bug 8028428 8244146
  * @summary Test that only 'public' and 'abstract' elements compile
- * @compile/fail/ref=AnnotationTypeElementModifiers.out -XDrawDiagnostics AnnotationTypeElementModifiers.java
+ * @compile/fail/ref=AnnotationTypeElementModifiers.out -XDrawDiagnostics --release 16 AnnotationTypeElementModifiers.java
+ * @compile/fail/ref=AnnotationTypeElementModifiers.out -XDrawDiagnostics -Xlint:-strictfp AnnotationTypeElementModifiers.java
  */
 
 public @interface AnnotationTypeElementModifiers {

test/langtools/tools/javac/annotations/AnnotationTypeElementModifiers.out

@@ -1,21 +1,21 @@
-AnnotationTypeElementModifiers.java:17:17: compiler.err.mod.not.allowed.here: private
 AnnotationTypeElementModifiers.java:18:17: compiler.err.mod.not.allowed.here: private
-AnnotationTypeElementModifiers.java:20:19: compiler.err.mod.not.allowed.here: protected
+AnnotationTypeElementModifiers.java:19:17: compiler.err.mod.not.allowed.here: private
 AnnotationTypeElementModifiers.java:21:19: compiler.err.mod.not.allowed.here: protected
-AnnotationTypeElementModifiers.java:23:16: compiler.err.mod.not.allowed.here: static
+AnnotationTypeElementModifiers.java:22:19: compiler.err.mod.not.allowed.here: protected
 AnnotationTypeElementModifiers.java:24:16: compiler.err.mod.not.allowed.here: static
-AnnotationTypeElementModifiers.java:26:15: compiler.err.mod.not.allowed.here: final
+AnnotationTypeElementModifiers.java:25:16: compiler.err.mod.not.allowed.here: static
 AnnotationTypeElementModifiers.java:27:15: compiler.err.mod.not.allowed.here: final
-AnnotationTypeElementModifiers.java:29:22: compiler.err.mod.not.allowed.here: synchronized
+AnnotationTypeElementModifiers.java:28:15: compiler.err.mod.not.allowed.here: final
 AnnotationTypeElementModifiers.java:30:22: compiler.err.mod.not.allowed.here: synchronized
-AnnotationTypeElementModifiers.java:32:18: compiler.err.mod.not.allowed.here: volatile
+AnnotationTypeElementModifiers.java:31:22: compiler.err.mod.not.allowed.here: synchronized
 AnnotationTypeElementModifiers.java:33:18: compiler.err.mod.not.allowed.here: volatile
-AnnotationTypeElementModifiers.java:35:19: compiler.err.mod.not.allowed.here: transient
+AnnotationTypeElementModifiers.java:34:18: compiler.err.mod.not.allowed.here: volatile
 AnnotationTypeElementModifiers.java:36:19: compiler.err.mod.not.allowed.here: transient
-AnnotationTypeElementModifiers.java:38:16: compiler.err.mod.not.allowed.here: native
+AnnotationTypeElementModifiers.java:37:19: compiler.err.mod.not.allowed.here: transient
 AnnotationTypeElementModifiers.java:39:16: compiler.err.mod.not.allowed.here: native
-AnnotationTypeElementModifiers.java:41:20: compiler.err.mod.not.allowed.here: strictfp
+AnnotationTypeElementModifiers.java:40:16: compiler.err.mod.not.allowed.here: native
 AnnotationTypeElementModifiers.java:42:20: compiler.err.mod.not.allowed.here: strictfp
-AnnotationTypeElementModifiers.java:44:17: compiler.err.mod.not.allowed.here: default
+AnnotationTypeElementModifiers.java:43:20: compiler.err.mod.not.allowed.here: strictfp
 AnnotationTypeElementModifiers.java:45:17: compiler.err.mod.not.allowed.here: default
+AnnotationTypeElementModifiers.java:46:17: compiler.err.mod.not.allowed.here: default
 20 errors

test/langtools/tools/javac/annotations/typeAnnotations/classfile/NestedLambdasCastedTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,7 @@
  *          jdk.compiler/com.sun.tools.javac.main
  *          jdk.jdeps/com.sun.tools.javap
  * @build toolbox.ToolBox toolbox.JavapTask
- * @run compile -g NestedLambdasCastedTest.java
+ * @run compile -source 16 -target 16 -g NestedLambdasCastedTest.java
  * @run main NestedLambdasCastedTest
  */
 

test/langtools/tools/javac/defaultMethods/CheckACC_STRICTFlagOnDefaultMethodTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,6 +26,7 @@
  * @bug 8012723
  * @summary strictfp interface misses strictfp modifer on default method
  * @modules jdk.jdeps/com.sun.tools.classfile
+ * @compile -source 16 -target 16 CheckACC_STRICTFlagOnDefaultMethodTest.java
  * @run main CheckACC_STRICTFlagOnDefaultMethodTest
  */
 

test/langtools/tools/javac/diags/examples/UnneededStrictfpWarning.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+// key: compiler.warn.strictfp
+// options: -Xlint:strictfp
+
+strictfp class UnneededStrictfpWarning {
+}

test/langtools/tools/javac/lambda/LambdaTestStrictFPFlag.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,6 +26,8 @@
  * @bug 8046060
  * @summary Different results of floating point multiplication for lambda code block
  * @modules jdk.jdeps/com.sun.tools.classfile
+ * @compile -source 16 -target 16 LambdaTestStrictFPFlag.java
+ * @run main LambdaTestStrictFPFlag
  */
 
 import java.io.*;

test/langtools/tools/javac/processing/model/element/ObsoleteStrictfp/StrictfpHost.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * Enclosing class for several strictfp-using types and methods.
+ *
+ * In the JVM, the ACC_STRICT bit is only defined for
+ * methods/constructors and *not* classes/interfaces. Therefore, for
+ * the checking in this test, the @StrictfpInSource annotation is only
+ * applied to methods/constructors.
+ */
+public class StrictfpHost {
+    public strictfp interface StrictfpInterface {
+        // Implicitly strictfp
+        @StrictfpInSource
+        default double foo() {return 42.0;}
+    }
+
+    public strictfp class StrictfpClass {
+        // Implicitly strictfp
+        @StrictfpInSource
+        public StrictfpClass() {
+            super();
+        }
+    }
+
+    @StrictfpInSource
+    public strictfp static void main(String... args) {
+        return;
+    }
+}

test/langtools/tools/javac/processing/model/element/ObsoleteStrictfp/StrictfpInSource.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.lang.annotation.*;
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.*;
+
+
+/**
+ * At the JVM level, the ACC_STRICT bit is only defined for
+ * methods/constructors, unlike where strictfp can be applied in
+ * sources.
+ */
+@Retention(RUNTIME)
+@Target({METHOD, CONSTRUCTOR})
+public @interface StrictfpInSource {}

test/langtools/tools/javac/processing/model/element/ObsoleteStrictfp/TestStrictfpRetention.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8244146
+ * @summary Test test and class file retention of strictfp.
+ * @compile --release 16 TestStrictfpRetention.java StrictfpInSource.java
+ * @compile         -processor   TestStrictfpRetention --release 16                       StrictfpHost.java
+ * @compile/process -processor   TestStrictfpRetention --release 16  -proc:only           StrictfpHost
+ * @compile         -processor   TestStrictfpRetention               -proc:only           StrictfpHost.java
+ * @compile         -processor   TestStrictfpRetention -source 16                         StrictfpHost.java
+ * @compile/process -processor   TestStrictfpRetention              -AstrictfpNotExpected StrictfpHost
+ */
+
+import java.util.Objects;
+import java.util.Set;
+import javax.annotation.processing.*;
+import javax.lang.model.SourceVersion;
+import static javax.lang.model.SourceVersion.*;
+import javax.lang.model.element.*;
+import javax.lang.model.util.*;
+import static javax.tools.Diagnostic.Kind.*;
+
+import static javax.lang.model.element.Modifier.*;
+
+/**
+ * The StrictfpInSource annotation marks whether or not the element in
+ * source was declared strictp in its source form. For release 16 (and
+ * earlier releases), the strictfp-in-source status and
+ * strictfp-in-class file status should generally match. (Per JLS,
+ * some elements are implicitly strictfp).
+ *
+ * Under release 17 and later releases reflecting JEP 306, while
+ * strictfp can be present in the source, it is *not* persisted to the
+ * class file for methods/constructors where ACC_STRICT can be
+ * applied. (The ACC_STRICT modifier is not defined for
+ * classes/interfaces in the JVM.)
+ *
+ * This test checks that the strictfp modifier of the annotated
+ * elements is as expected in the four combinations:
+ *
+ * (source, class file) X (--release 16, current release)
+ *
+ * As well as the mixed combination of -source 16 and current release
+ * as the implicit target.
+ */
+@SupportedOptions("strictfpNotExpected")
+@SupportedAnnotationTypes("StrictfpInSource")
+public class TestStrictfpRetention extends AbstractProcessor {
+    public boolean process(Set<? extends TypeElement> annotations,
+                           RoundEnvironment roundEnv) {
+        if (!roundEnv.processingOver()) {
+            boolean annotatedElementsFound = false;
+            boolean strictfpExpected = !processingEnv.getOptions().containsKey("strictfpNotExpected");
+            var messager = processingEnv.getMessager();
+
+            for (Element e: roundEnv.getElementsAnnotatedWith(StrictfpInSource.class)) {
+                annotatedElementsFound = true;
+
+                boolean strictfpPresent =  e.getModifiers().contains(STRICTFP);
+                if (strictfpPresent != strictfpExpected) {
+                    messager.printMessage(ERROR, "Unexpected strictfp status: " + strictfpPresent + " " + e, e);
+                }
+            }
+
+            if (!annotatedElementsFound) {
+                messager.printMessage(ERROR, "No annotated elements found");
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public SourceVersion getSupportedSourceVersion() {
+        return SourceVersion.latest();
+    }
+}

test/langtools/tools/javac/processing/model/element/TestExecutableElement.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -143,8 +143,8 @@ interface ProviderOfDefault {
     boolean process(Set<? extends TypeElement> annotations,
                     RoundEnvironment roundEnv);
 
-    @IsDefault(value=true, expectedTextRegex="\\s*@IsDefault\\(.*\\)\\s*default strictfp void quux\\(\\);\\s*$")
+    @IsDefault(value=true, expectedTextRegex="\\s*@IsDefault\\(.*\\)\\s*default void quux\\(\\);\\s*$")
-    default strictfp void quux() {};
+    default void quux() {};
     @IsDefault(false)
     static void statik() {}
 }

test/langtools/tools/javac/warnings/UnneededStrictfpWarningToolBox.java

@@ -0,0 +1,262 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8244146
+ * @summary Verify expected strictfp warnings are producted or not produced
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.main
+ * @build toolbox.ToolBox toolbox.JavacTask toolbox.TestRunner
+ * @run main UnneededStrictfpWarningToolBox
+ */
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.List;
+
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.util.EnumSet;
+import javax.tools.JavaFileManager;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardLocation;
+import javax.tools.ToolProvider;
+import toolbox.JavacTask;
+import toolbox.Task;
+import toolbox.Task.Expect;
+import toolbox.TestRunner;
+import toolbox.ToolBox;
+
+public class UnneededStrictfpWarningToolBox extends TestRunner {
+
+    private final ToolBox tb = new ToolBox();
+    private final String fileSep = System.getProperty("file.separator");
+
+    public UnneededStrictfpWarningToolBox() {
+        super(System.err);
+    }
+
+    public static void main(String... args) throws Exception {
+        new UnneededStrictfpWarningToolBox().runTests();
+    }
+
+    private void checkLog(List<String> log, List<String> expected) {
+        if (!expected.equals(log)) {
+            throw new AssertionError("Unexpected output: " + log);
+        }
+    }
+
+    private void checkEmptyLog(List<String> log) {
+        checkLog(log, List.of(""));
+    }
+
+    @Test
+    public void testWithAndWithOutLint(Path base) throws IOException {
+        Path src = base.resolve("src");
+
+        tb.writeJavaFiles(src, UNNEEDED_STRICTFP_WARNING1_NO_SUPPRESSION);
+        Path classes = base.resolve("classes");
+        tb.createDirectories(classes);
+
+        List<String> log;
+
+        // Warning not enabled, no messages expected
+        log = new JavacTask(tb)
+                .options("--release", "16", "-Werror")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+        checkEmptyLog(log);
+
+        // Warning not enabled, no messages expected
+        log = new JavacTask(tb)
+                .options("-Xlint:-strictfp", "-Werror")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+        checkEmptyLog(log);
+
+        // Warning enabled, 5 messages expected
+        log = new JavacTask(tb)
+            .options("-XDrawDiagnostics")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+
+        var expected = List.of("UnneededStrictfpWarning1.java:1:17: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning1.java:10:10: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning1.java:12:29: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning1.java:16:28: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning1.java:18:21: compiler.warn.strictfp",
+                               "5 warnings");
+        checkLog(log, expected);
+    }
+
+    @Test
+    public void testTopLevelSuppression(Path base) throws IOException {
+        Path src = base.resolve("src");
+
+        tb.writeJavaFiles(src, UNNEEDED_STRICTFP_WARNING2_TOP_LEVEL_SUPPRESSION);
+        Path classes = base.resolve("classes");
+        tb.createDirectories(classes);
+
+        List<String> log;
+
+        // Warning implicitly enabled, no messages expected
+        log = new JavacTask(tb)
+                .options("-Werror")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+        checkEmptyLog(log);
+
+        // Warning explicitly enabled, no messages expected
+        log = new JavacTask(tb)
+                .options("-Xlint:strictfp", "-Werror")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+        checkEmptyLog(log);
+    }
+
+    @Test
+    public void testInnerSuppression(Path base) throws IOException {
+        Path src = base.resolve("src");
+
+        tb.writeJavaFiles(src, UNNEEDED_STRICTFP_WARNING3_INNER_SUPPRESSION);
+        Path classes = base.resolve("classes");
+        tb.createDirectories(classes);
+
+        // Warning enabled, 3 messages expected
+        List<String> log = new JavacTask(tb)
+            .options("-XDrawDiagnostics")
+                .outdir(classes)
+                .files(tb.findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+
+        var expected = List.of("UnneededStrictfpWarning3.java:1:17: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning3.java:10:10: compiler.warn.strictfp",
+                               "UnneededStrictfpWarning3.java:17:28: compiler.warn.strictfp",
+                               "3 warnings");
+        checkLog(log, expected);
+    }
+
+    protected void runTests() throws Exception {
+        runTests(m -> new Object[] { Paths.get(m.getName()).toAbsolutePath() });
+    }
+
+    // If warnings are enabled, should generate 5 warnings for the 5
+    // explicit uses of strictfp.
+    private static final String UNNEEDED_STRICTFP_WARNING1_NO_SUPPRESSION =
+        """
+        public strictfp class UnneededStrictfpWarning1 {
+            // Implicit strictfp, no warning
+            public UnneededStrictfpWarning1() {super();}
+
+            public static void main(String... args) {
+                return;
+            }
+        }
+
+        strictfp interface StrictfpInterface {
+            default double foo() {return 42.0;};
+            default strictfp double bar() {return 21.0;};
+        }
+
+        class StrictfpMethod {
+            static strictfp double quux() {return 42.0;}
+
+            static strictfp class NestedStrictfpClass {}
+        }
+        """;
+
+    // If warnings are enabled, no warnings should be generated due to
+    // suppression at the top-most level.
+    private static final String UNNEEDED_STRICTFP_WARNING2_TOP_LEVEL_SUPPRESSION =
+        """
+        @SuppressWarnings("strictfp")
+        public strictfp class UnneededStrictfpWarning2 {
+            // Implicit strictfp, no warning
+            public UnneededStrictfpWarning2() {super();}
+
+            public static void main(String... args) {
+                return;
+            }
+        }
+
+        @SuppressWarnings("strictfp")
+        strictfp interface StrictfpInterface {
+            default double foo() {return 42.0;};
+            default strictfp double bar() {return 21.0;};
+        }
+
+        @SuppressWarnings("strictfp")
+        class StrictfpMethod {
+            static strictfp double quux() {return 42.0;}
+
+            static strictfp class NestedStrictfpClass {}
+        }
+        """;
+
+    // If warnings are enabled, 3 warnings should be generated.
+    private static final String UNNEEDED_STRICTFP_WARNING3_INNER_SUPPRESSION =
+        """
+        public strictfp class UnneededStrictfpWarning3 {
+            // Implicit strictfp, no warning
+            public UnneededStrictfpWarning3() {super();}
+
+            public static void main(String... args) {
+                return;
+            }
+        }
+
+        strictfp interface StrictfpInterface {
+            default double foo() {return 42.0;};
+            @SuppressWarnings("strictfp")
+            default strictfp double bar() {return 21.0;};
+        }
+
+        class StrictfpMethod {
+            static strictfp double quux() {return 42.0;}
+
+            @SuppressWarnings("strictfp")
+            static strictfp class NestedStrictfpClass {}
+        }
+        """;
+}