8015831: Add lint check for calling overridable methods from a constructor

6557145: Warn about calling abstract methods in constructors

Reviewed-by: ihse, vromero, mcimadamore

make/CompileDemos.gmk

@@ -171,41 +171,41 @@ $(BUILD_DEMO_CodePointIM_JAR): $(CODEPOINT_METAINF_SERVICE_FILE)
 
 $(eval $(call SetupBuildDemo, FileChooserDemo, \
     DEMO_SUBDIR := jfc, \
-    DISABLED_WARNINGS := rawtypes deprecation unchecked, \
+    DISABLED_WARNINGS := rawtypes deprecation unchecked this-escape, \
 ))
 
 $(eval $(call SetupBuildDemo, SwingSet2, \
     DEMO_SUBDIR := jfc, \
     EXTRA_COPY_TO_JAR := .java, \
     EXTRA_MANIFEST_ATTR := SplashScreen-Image: resources/images/splash.png, \
-    DISABLED_WARNINGS := rawtypes deprecation unchecked static serial cast, \
+    DISABLED_WARNINGS := rawtypes deprecation unchecked static serial cast this-escape, \
 ))
 
 $(eval $(call SetupBuildDemo, Font2DTest, \
-    DISABLED_WARNINGS := rawtypes deprecation unchecked serial cast, \
+    DISABLED_WARNINGS := rawtypes deprecation unchecked serial cast this-escape, \
     DEMO_SUBDIR := jfc, \
 ))
 
 $(eval $(call SetupBuildDemo, J2Ddemo, \
     DEMO_SUBDIR := jfc, \
     MAIN_CLASS := java2d.J2Ddemo, \
-    DISABLED_WARNINGS := rawtypes deprecation unchecked cast lossy-conversions, \
+    DISABLED_WARNINGS := rawtypes deprecation unchecked cast lossy-conversions this-escape, \
     JAR_NAME := J2Ddemo, \
 ))
 
 $(eval $(call SetupBuildDemo, Metalworks, \
-    DISABLED_WARNINGS := rawtypes unchecked, \
+    DISABLED_WARNINGS := rawtypes unchecked this-escape, \
     DEMO_SUBDIR := jfc, \
 ))
 
 $(eval $(call SetupBuildDemo, Notepad, \
-    DISABLED_WARNINGS := rawtypes, \
+    DISABLED_WARNINGS := rawtypes this-escape, \
     DEMO_SUBDIR := jfc, \
 ))
 
 $(eval $(call SetupBuildDemo, Stylepad, \
     DEMO_SUBDIR := jfc, \
-    DISABLED_WARNINGS := rawtypes unchecked, \
+    DISABLED_WARNINGS := rawtypes unchecked this-escape, \
     EXTRA_SRC_DIR := $(DEMO_SHARE_SRC)/jfc/Notepad, \
     EXCLUDE_FILES := $(DEMO_SHARE_SRC)/jfc/Notepad/README.txt, \
 ))
@@ -215,11 +215,12 @@ $(eval $(call SetupBuildDemo, SampleTree, \
 ))
 
 $(eval $(call SetupBuildDemo, TableExample, \
-    DISABLED_WARNINGS := rawtypes unchecked deprecation, \
+    DISABLED_WARNINGS := rawtypes unchecked deprecation this-escape, \
     DEMO_SUBDIR := jfc, \
 ))
 
 $(eval $(call SetupBuildDemo, TransparentRuler, \
+    DISABLED_WARNINGS := this-escape, \
     DEMO_SUBDIR := jfc, \
     MAIN_CLASS := transparentruler.Ruler, \
 ))

make/CompileModuleTools.gmk

@@ -53,7 +53,7 @@ $(eval $(call SetupJavaCompilation, BUILD_JIGSAW_TOOLS, \
                 build/tools/jigsaw, \
     COPY := .properties .html, \
     BIN := $(TOOLS_CLASSES_DIR), \
-    DISABLED_WARNINGS := fallthrough, \
+    DISABLED_WARNINGS := fallthrough this-escape, \
     JAVAC_FLAGS := \
         --add-modules jdk.jdeps \
         --add-exports java.base/jdk.internal.module=ALL-UNNAMED \

make/modules/java.base/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 JAVAC_FLAGS += -XDstringConcat=inline \

make/modules/java.datatransfer/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 COPY += flavormap.properties

make/modules/java.desktop/Java.gmk

@@ -23,7 +23,7 @@
 # questions.
 #
 
-DISABLED_WARNINGS_java += lossy-conversions
+DISABLED_WARNINGS_java += lossy-conversions this-escape
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 COPY += .gif .png .wav .txt .xml .css .pf

make/modules/java.logging/Java.gmk

@@ -23,5 +23,7 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'

make/modules/java.management/Java.gmk

@@ -23,5 +23,7 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'

make/modules/java.naming/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 CLEAN += jndiprovider.properties

make/modules/java.net.http/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/java.rmi/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 CLEAN_FILES += $(wildcard \

make/modules/java.security.jgss/Java.gmk

@@ -23,5 +23,7 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'

make/modules/java.security.sasl/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/java.sql.rowset/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 CLEAN_FILES += $(wildcard \

make/modules/java.sql/Java.gmk

@@ -23,5 +23,7 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'

make/modules/java.xml.crypto/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:java.*,javax.*'
 COPY += .dtd .xml

make/modules/java.xml/Java.gmk

@@ -23,7 +23,7 @@
 # questions.
 #
 
-DISABLED_WARNINGS_java += lossy-conversions
+DISABLED_WARNINGS_java += lossy-conversions this-escape
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:$(call CommaList, javax.xml.catalog javax.xml.datatype \
     javax.xml.transform javax.xml.validation javax.xml.xpath)'

make/modules/jdk.charsets/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .dat

make/modules/jdk.compiler/Gendata.gmk

@@ -57,7 +57,7 @@ $(eval $(call SetupJavaCompilation, COMPILE_CREATE_SYMBOLS, \
         $(TOPDIR)/src/jdk.jdeps/share/classes, \
     INCLUDES := build/tools/symbolgenerator com/sun/tools/classfile, \
     BIN := $(BUILDTOOLS_OUTPUTDIR)/create_symbols, \
-    DISABLED_WARNINGS := options, \
+    DISABLED_WARNINGS := options this-escape, \
     JAVAC_FLAGS := \
         $(INTERIM_LANGTOOLS_ARGS) \
         $(COMPILECREATESYMBOLS_ADD_EXPORTS), \

make/modules/jdk.compiler/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 DOCLINT += -Xdoclint:all/protected \
     '-Xdoclint/package:-com.sun.tools.*,-jdk.internal.*,sun.tools.serialver.resources.*'
 JAVAC_FLAGS += -XDstringConcat=inline

make/modules/jdk.crypto.ec/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/jdk.crypto.mscapi/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/jdk.hotspot.agent/Java.gmk

@@ -24,5 +24,5 @@
 #
 
 DISABLED_WARNINGS_java += rawtypes serial cast static overrides \
-    fallthrough
+    fallthrough this-escape
 COPY += .gif .png .properties

make/modules/jdk.httpserver/Java.gmk

@@ -23,4 +23,4 @@
 # questions.
 #
 
-DISABLED_WARNINGS_java += missing-explicit-ctor
+DISABLED_WARNINGS_java += missing-explicit-ctor this-escape

make/modules/jdk.internal.jvmstat/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += aliasmap

make/modules/jdk.internal.le/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .properties .caps .txt

make/modules/jdk.internal.opt/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .properties

make/modules/jdk.internal.vm.ci/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 # -parameters provides method's parameters information in class file,
 # JVMCI compilers make use of that information for various sanity checks.
 # Don't use Indy strings concatenation to have good JVMCI startup performance.

make/modules/jdk.javadoc/Gendata.gmk

@@ -55,7 +55,7 @@ $(eval $(call SetupJavaCompilation, COMPILE_CREATE_SYMBOLS, \
         $(TOPDIR)/src/jdk.jdeps/share/classes, \
     INCLUDES := build/tools/symbolgenerator com/sun/tools/classfile, \
     BIN := $(BUILDTOOLS_OUTPUTDIR)/create_symbols_javadoc, \
-    DISABLED_WARNINGS := options, \
+    DISABLED_WARNINGS := options this-escape, \
     JAVAC_FLAGS := \
         $(INTERIM_LANGTOOLS_ARGS) \
         $(COMPILECREATESYMBOLS_ADD_EXPORTS), \

make/modules/jdk.javadoc/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .xml .css .svg .js .js.template .png .txt

make/modules/jdk.jcmd/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += _options

make/modules/jdk.jconsole/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .gif .png
 
 CLEAN_FILES += $(wildcard \

make/modules/jdk.jdeps/Gensrc.gmk

@@ -26,6 +26,8 @@
 include GensrcCommon.gmk
 include GensrcProperties.gmk
 
+DISABLED_WARNINGS_java += this-escape
+
 $(eval $(call SetupVersionProperties, JAVAP_VERSION, \
     com/sun/tools/javap/resources/version.properties))
 

make/modules/jdk.jdeps/Java.gmk

@@ -25,6 +25,8 @@
 
 COPY += .txt
 
+DISABLED_WARNINGS_java += this-escape
+
 CLEAN_FILES += $(wildcard \
     $(TOPDIR)/src/jdk.jdeps/share/classes/com/sun/tools/jdeps/resources/*.properties \
     $(TOPDIR)/src/jdk.jdeps/share/classes/com/sun/tools/javap/resources/*.properties)

make/modules/jdk.jdeps/Launcher.gmk

@@ -25,6 +25,8 @@
 
 include LauncherCommon.gmk
 
+DISABLED_WARNINGS_java += this-escape
+
 $(eval $(call SetupBuildLauncher, javap, \
     MAIN_CLASS := com.sun.tools.javap.Main, \
     CFLAGS := -DEXPAND_CLASSPATH_WILDCARDS, \

make/modules/jdk.jdi/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 EXCLUDES += \
     com/sun/tools/example/debug/bdi \
     com/sun/tools/example/debug/event \

make/modules/jdk.jlink/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/jdk.jpackage/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .gif .png .txt .spec .script .prerm .preinst \
     .postrm .postinst .list .sh .desktop .copyright .control .plist .template \
     .icns .scpt .wxs .wxl .wxi .ico .bmp .tiff .service

make/modules/jdk.jshell/Java.gmk

@@ -23,4 +23,6 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += .jsh .properties

make/modules/jdk.jstatd/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/jdk.localedata/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 COPY += _dict _th
 # Exclude BreakIterator classes that are just used in compile process to generate
 # data files and shouldn't go in the product

make/modules/jdk.management/Java.gmk

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2023, 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.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# 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.
+#
+
+DISABLED_WARNINGS_java += this-escape

make/modules/jdk.sctp/Java.gmk

@@ -23,6 +23,8 @@
 # questions.
 #
 
+DISABLED_WARNINGS_java += this-escape
+
 # No SCTP implementation on Mac OS X or AIX. These classes should be excluded.
 SCTP_IMPL_CLASSES = \
     $(TOPDIR)/src/jdk.sctp/unix/classes/sun/nio/ch/sctp/AssociationChange.java \

make/test/BuildFailureHandler.gmk

@@ -51,7 +51,7 @@ $(eval $(call SetupJavaCompilation, BUILD_FAILURE_HANDLER, \
     TARGET_RELEASE := $(TARGET_RELEASE_BOOTJDK), \
     SRC := $(FH_BASEDIR)/src/share/classes $(FH_BASEDIR)/src/share/conf, \
     BIN := $(FH_SUPPORT)/classes, \
-    DISABLED_WARNINGS := options serial try, \
+    DISABLED_WARNINGS := options serial try this-escape, \
     COPY := .properties, \
     CLASSPATH := $(JTREG_JAR) $(TOOLS_JAR), \
     JAR := $(FH_JAR), \

make/test/BuildMicrobenchmark.gmk

@@ -76,7 +76,7 @@ $(eval $(call SetupJavaCompilation, BUILD_INDIFY, \
     TARGET_RELEASE := $(TARGET_RELEASE_BOOTJDK), \
     SRC := $(TOPDIR)/test/jdk/java/lang/invoke, \
     INCLUDE_FILES := indify/Indify.java, \
-    DISABLED_WARNINGS := rawtypes serial options, \
+    DISABLED_WARNINGS := this-escape rawtypes serial options, \
     BIN := $(MICROBENCHMARK_TOOLS_CLASSES), \
     JAVAC_FLAGS := -XDstringConcat=inline -Xprefer:newer, \
 ))
@@ -91,7 +91,7 @@ $(eval $(call SetupJavaCompilation, BUILD_JDK_MICROBENCHMARK, \
     TARGET_RELEASE := $(TARGET_RELEASE_NEWJDK_UPGRADED), \
     SMALL_JAVA := false, \
     CLASSPATH := $(MICROBENCHMARK_CLASSPATH), \
-    DISABLED_WARNINGS := processing rawtypes cast serial preview, \
+    DISABLED_WARNINGS := this-escape processing rawtypes cast serial preview, \
     SRC := $(MICROBENCHMARK_SRC), \
     BIN := $(MICROBENCHMARK_CLASSES), \
     JAVAC_FLAGS := --add-exports java.base/sun.security.util=ALL-UNNAMED \

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

@@ -306,6 +306,11 @@ public class Lint
          */
         TEXT_BLOCKS("text-blocks"),
 
+        /**
+         * Warn about possible 'this' escapes before subclass instance is fully initialized.
+         */
+        THIS_ESCAPE("this-escape"),
+
         /**
          * Warn about issues relating to use of try blocks (i.e. try-with-resources)
          */

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

@@ -224,6 +224,7 @@ public class Flow {
         new AssignAnalyzer().analyzeTree(env, make);
         new FlowAnalyzer().analyzeTree(env, make);
         new CaptureAnalyzer().analyzeTree(env, make);
+        new ThisEscapeAnalyzer(names, syms, types, log, lint).analyzeTree(env);
     }
 
     public void analyzeLambda(Env<AttrContext> env, JCLambda that, TreeMaker make, boolean speculative) {

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

@@ -662,6 +662,12 @@ compiler.err.not.in.profile=\
 compiler.warn.forward.ref=\
     reference to variable ''{0}'' before it has been initialized
 
+compiler.warn.possible.this.escape=\
+    possible ''this'' escape before subclass is fully initialized
+
+compiler.warn.possible.this.escape.location=\
+    previous possible ''this'' escape happens here via invocation
+
 compiler.err.illegal.self.ref=\
     self-reference in initializer
 

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

@@ -258,6 +258,10 @@ javac.opt.Xlint.desc.strictfp=\
 javac.opt.Xlint.desc.text-blocks=\
     Warn about inconsistent white space characters in text block indentation.
 
+javac.opt.Xlint.desc.this-escape=\
+    Warn when a constructor invokes a method that could be overriden in an external subclass.\n\
+\                         Such a method would execute before the subclass constructor completes its initialization.
+
 javac.opt.Xlint.desc.try=\
     Warn about issues relating to use of try blocks (i.e. try-with-resources).
 

src/jdk.compiler/share/classes/module-info.java

@@ -184,6 +184,7 @@ import javax.tools.StandardLocation;
  * <tr><th scope="row">{@code strictfp}             <td>unnecessary use of the {@code strictfp} modifier
  * <tr><th scope="row">{@code synchronization}      <td>synchronization attempts on instances of value-based classes
  * <tr><th scope="row">{@code text-blocks}          <td>inconsistent white space characters in text block indentation
+ * <tr><th scope="row">{@code this-escape}          <td>superclass constructor leaking {@code this} before subclass initialized
  * <tr><th scope="row">{@code try}                  <td>issues relating to use of {@code try} blocks
  *                                                      (that is, try-with-resources)
  * <tr><th scope="row">{@code unchecked}            <td>unchecked operations

src/jdk.compiler/share/man/javac.1

@@ -776,6 +776,9 @@ instances of value-based classes.
 \f[V]text-blocks\f[R]: Warns about inconsistent white space characters
 in text block indentation.
 .IP \[bu] 2
+\f[V]this-escape\f[R]: Warns about constructors leaking
+\f[V]this\f[R] prior to subclass initialization.
+.IP \[bu] 2
 \f[V]try\f[R]: Warns about the issues relating to the use of try blocks
 (that is, try-with-resources).
 .IP \[bu] 2
@@ -2213,6 +2216,48 @@ Alternately, you can remove the \f[V]static\f[R] keyword from the
 declaration of the method \f[V]m1\f[R].
 .RE
 .TP
+\f[V]this\-escape\f[R]
+Warns about constructors leaking \f[V]this\f[R] prior to subclass
+initialization.
+For example, this class:
+.RS
+.IP
+.nf
+\f[CB]
+public class MyClass {
+  public MyClass() {
+    System.out.println(this.hashCode());
+  }
+}
+\f[R]
+.fi
+.PP
+generates the following warning:
+.IP
+.nf
+\f[CB]
+MyClass.java:3: warning: [this-escape] possible 'this' escape
+                         before subclass is fully initialized
+    System.out.println(this.hashCode());
+                                    ^
+\f[R]
+.fi
+.PP
+A 'this' escape warning is generated when a constructor does something
+that might result in a subclass method being invoked before the
+constructor returns.
+In such cases the subclass method would be operating on an incompletely
+initialized instance.
+In the above example, a subclass of \f[V]MyClass\f[R] that overrides
+\f[V]hashCode()\f[R] to incorporate its own fields would likely produce
+an incorrect result when invoked as shown.
+.PP
+Warnings are only generated if a subclass could exist that is outside
+of the current module (or package, if no module) being compiled.
+So, for example, constructors in final and non-public classes do not
+generate warnings.
+.RE
+.TP
 \f[V]try\f[R]
 Warns about issues relating to the use of \f[V]try\f[R] blocks,
 including try-with-resources statements.

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

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2023, 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.possible.this.escape
+// key: compiler.warn.possible.this.escape.location
+// options: -Xlint:this-escape
+
+public class ThisEscape {
+
+    public ThisEscape() {
+        this.method();
+    }
+
+    public final void method() {
+        this.hashCode();
+    }
+}

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

@@ -0,0 +1,604 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8015831
+ * @compile/ref=ThisEscape.out -Xlint:this-escape -XDrawDiagnostics ThisEscape.java
+ * @summary Verify 'this' escape detection
+ */
+
+import java.util.function.*;
+
+public class ThisEscape {
+
+    // Verify 'this' escape detection can follow references embedded as array elements
+    public static class ThisEscapeArrayElement {
+
+        public ThisEscapeArrayElement() {
+            final Object[][] array = new Object[][] { { this } };
+            ((ThisEscapeArrayElement)array[0][0]).mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify basic 'this' escape detection
+    public static class ThisEscapeBasic {
+
+        public ThisEscapeBasic() {
+            this.mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape detection can follow references through various Java code structures
+    public static class ThisEscapeComplex {
+
+        public ThisEscapeComplex() {
+            this.method1().mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+
+        private ThisEscapeComplex method1() {
+            while (true) {
+                do {
+                    for (ThisEscapeComplex x = this.method2(); new Object().hashCode() < 10; ) {
+                        for (int y : new int[] { 123, 456 }) {
+                            return x;
+                        }
+                    }
+                } while (true);
+            }
+        }
+
+        private ThisEscapeComplex method2() {
+            switch (new Object().hashCode()) {
+            case 1:
+            case 2:
+            case 3:
+                return null;
+            default:
+                return this.method3();
+            }
+        }
+
+        private ThisEscapeComplex method3() {
+            return switch (new Object().hashCode()) {
+                case 1, 2, 3 -> this.method4();
+                default -> null;
+            };
+        }
+
+        private ThisEscapeComplex method4() {
+            return ThisEscapeComplex.this.method5();
+        }
+
+        private ThisEscapeComplex method5() {
+            final ThisEscapeComplex foo = this.method6();
+            return foo;
+        }
+
+        private ThisEscapeComplex method6() {
+            synchronized (new Object()) {
+                return this.method7();
+            }
+        }
+
+        private ThisEscapeComplex method7() {
+            ThisEscapeComplex x = null;
+            ThisEscapeComplex y = this.method8();
+            if (new Object().hashCode() == 3)
+                return x;
+            else
+                return y;
+        }
+
+        private ThisEscapeComplex method8() {
+            return (ThisEscapeComplex)(Object)this.method9();
+        }
+
+        private ThisEscapeComplex method9() {
+            return new Object().hashCode() == 3 ? this : null;
+        }
+    }
+
+    // Verify pruning of 'this' escape warnings for various constructors
+    public static class ThisEscapeCtors {
+
+        // This constructor should NOT generate a warning because it would be a
+        // duplicate of the warning already generated for ThisEscapeCtors(short).
+        public ThisEscapeCtors(char x) {
+            this((short)x);
+        }
+
+        // This constructor should generate a warning because it invokes leaky this()
+        // and is accessible to subclasses.
+        public ThisEscapeCtors(short x) {
+            this();
+        }
+
+        // This constructor should generate a warning because it invokes leaky this()
+        // and is accessible to subclasses.
+        public ThisEscapeCtors(int x) {
+            this();
+        }
+
+        // This constructor should NOT generate a warning because it is not accessbile
+        // to subclasses. However, other constructors do invoke it, and that should cause
+        // them to generate an indirect warning.
+        private ThisEscapeCtors() {
+            this.mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape detection in field initializers
+    public static class ThisEscapeFields {
+
+        private final int field1 = this.mightLeak1();
+
+        private final int field2 = this.mightLeak2();
+
+        public int mightLeak1() {
+            return 123;
+        }
+
+        public int mightLeak2() {
+            return 456;
+        }
+    }
+
+    // Verify 'this' escape detection properly handles lambdas
+    public static class ThisEscapeLambda {
+
+        public ThisEscapeLambda() {
+            Runnable r = () -> {
+                this.mightLeak();
+            };
+            System.out.println(r);
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape detection properly handles loop convergence
+    public static class ThisEscapeLoop {
+
+        public ThisEscapeLoop() {
+            ThisEscapeLoop ref1 = this;
+            ThisEscapeLoop ref2 = null;
+            ThisEscapeLoop ref3 = null;
+            ThisEscapeLoop ref4 = null;
+            for (int i = 0; i < 100; i++) {
+                ref4 = ref3;
+                ref3 = ref2;
+                ref2 = ref1;
+                if (ref4 != null)
+                    ref4.mightLeak();
+            }
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape detection handles leaks via outer 'this'
+    public static class ThisEscapeOuterThis {
+
+        public ThisEscapeOuterThis() {
+            new InnerClass();
+        }
+
+        public void mightLeak() {
+        }
+
+        public class InnerClass {
+
+            InnerClass() {
+                ThisEscapeOuterThis.this.mightLeak();
+            }
+        }
+
+        // No leak here because class 'Local' cannot be externally extended
+        public static void method1() {
+            class Local {
+                Local() {
+                    this.wontLeak();
+                }
+                void wontLeak() {
+                }
+            }
+        }
+    }
+
+    // Verify 'this' escape detection handles leaks via passing 'this' as a parameter
+    public static class ThisEscapeParameter {
+
+        public ThisEscapeParameter() {
+            ThisEscapeParameter.method(this);
+        }
+
+        public static void method(Object obj) {
+            obj.hashCode();
+        }
+    }
+
+    // Verify 'this' escape detection properly handles leaks via recursive methods
+    public static class ThisEscapeRecursion {
+
+        public ThisEscapeRecursion() {
+            this.noLeak(0);         // no leak here
+            this.mightLeak();       // possible leak here
+        }
+
+        public final void noLeak(int depth) {
+            if (depth < 10)
+                this.noLeak(depth - 1);
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify proper handling of 'this' escape warnings from method references
+    public static class ThisEscapeReference {
+
+    // Test 1 - ReferenceKind.SUPER
+
+        public static class Test1 {
+            public void mightLeak() {
+            }
+        }
+
+        public static class Test1b extends Test1 {
+            public Test1b() {
+                new Thread(super::mightLeak);   // this is a leak
+            }
+        }
+
+        public static class Test1c extends Test1 {
+            public Test1c() {
+                new Thread(super::notify);      // this is not a leak
+            }
+        }
+
+    // Test 2 - ReferenceKind.BOUND
+
+        public static class Test2 {
+
+            public Test2() {
+                new Thread(this::mightLeak);    // this is a leak
+            }
+
+            public Test2(int x) {
+                final Test2 foo = new Test2();
+                new Thread(foo::mightLeak);     // this is not a leak
+            }
+
+            public Test2(char x) {
+                new Thread(this::noLeak);       // this is not a leak
+            }
+
+            public void mightLeak() {
+            }
+
+            private void noLeak() {
+            }
+        }
+
+    // Test 3 - ReferenceKind.IMPLICIT_INNER
+
+        public static class Test3 {
+
+            public Test3() {
+                new Thread(Inner1::new);        // this is a leak
+            }
+
+            public Test3(int x) {
+                new Thread(Inner2::new);        // this is not a leak
+            }
+
+            public void mightLeak() {
+            }
+
+            public class Inner1 {
+                public Inner1() {
+                    Test3.this.mightLeak();
+                }
+            }
+
+            public class Inner2 {
+                public Inner2() {
+                    new Test3().mightLeak();
+                }
+            }
+        }
+
+    // Test 4 - ReferenceKind.UNBOUND, STATIC, TOPLEVEL, ARRAY_CTOR
+
+        public static class Test4 {
+
+            // ReferenceKind.UNBOUND
+            public Test4() {
+                Test4.bar(Test4::sameHashCode);
+            }
+
+            // ReferenceKind.STATIC
+            public Test4(int x) {
+                new Thread(Test4::noLeak);      // this is not a leak
+            }
+
+            // ReferenceKind.ARRAY_CTOR
+            public Test4(char x) {
+                Test4.foo(String[]::new);       // this is not a leak
+            }
+
+            // ReferenceKind.TOPLEVEL
+            public Test4(short x) {
+                Test4.foo(Test4::new);          // this is not a leak
+            }
+
+            public static void noLeak() {
+            }
+
+            public static void foo(IntFunction<?> x) {
+                x.hashCode();
+            }
+
+            public static void bar(BiPredicate<Test4, Object> x) {
+                x.hashCode();
+            }
+
+            public boolean sameHashCode(Object obj) {
+                return obj.hashCode() == this.hashCode();
+            }
+        }
+    }
+
+    // Verify 'this' escape detection properly handles leaks via method return values
+    public static class ThisEscapeReturnValue {
+
+        public ThisEscapeReturnValue() {
+            final Object rval = ThisEscapeReturnValue.method(this);
+            ((ThisEscapeReturnValue)rval).mightLeak();
+        }
+
+        public static Object method(Object obj) {
+            return obj;
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape detection from a thrown 'this'
+    public static class ThisEscapeThrown extends RuntimeException {
+
+        public ThisEscapeThrown(Object obj) {
+            if (obj == null)
+                throw this;
+        }
+    }
+
+    // Verify proper 'this' escape interpretation of unqualified non-static method invocations
+    public static class ThisEscapeUnqualified {
+
+        // This class has a leak
+        public static class Example1 {
+
+            public Example1() {
+                new Inner();
+            }
+
+            public final class Inner {
+                public Inner() {
+                    mightLeak();    // refers to Example1.mightLeak()
+                }
+            }
+
+            public void mightLeak() {
+            }
+        }
+
+        // This class does NOT have a leak
+        public static class Example2 {
+
+            public Example2() {
+                new Inner();
+            }
+
+            public final class Inner {
+                public Inner() {
+                    mightLeak();    // refers to Inner.mightLeak()
+                }
+
+                public void mightLeak() {
+                }
+            }
+
+            public void mightLeak() {
+            }
+        }
+    }
+
+    // Verify 'this' escape detection handles leaks via switch expression yields
+    public static class ThisEscapeYield {
+
+        public ThisEscapeYield(int x) {
+            ThisEscapeYield y = switch (x) {
+                case 3:
+                    if (x > 17)
+                        yield this;
+                    else
+                        yield null;
+                default:
+                    yield null;
+            };
+            if (y != null)
+                y.mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+    }
+
+    // Verify 'this' escape warnings can be properly suppressed on constructors
+    public static class ThisEscapeSuppressCtor {
+
+        private final int x = this.mightLeak();
+
+        @SuppressWarnings("this-escape")
+        public ThisEscapeSuppressCtor() {
+            this.mightLeak();
+        }
+
+        public int mightLeak() {
+            return 0;
+        }
+    }
+
+    // Verify 'this' escape warnings can be properly suppressed on fields
+    public static class ThisEscapeSuppressField {
+
+        @SuppressWarnings("this-escape")
+        private final int x = this.mightLeak();
+
+        public ThisEscapeSuppressField() {
+            this.mightLeak();
+        }
+
+        public int mightLeak() {
+            return 0;
+        }
+    }
+
+    // Verify 'this' escape warnings can be properly suppressed on classes
+    public static class ThisEscapeSuppressClass {
+
+        @SuppressWarnings("this-escape")
+        private final int x = this.mightLeak();
+
+        @SuppressWarnings("this-escape")
+        public ThisEscapeSuppressClass() {
+            this.mightLeak();
+        }
+
+        public int mightLeak() {
+            return 0;
+        }
+    }
+
+    // Verify 'this' escape detection doesn't generate certain false positives
+    public static class ThisEscapeNoEscapes {
+
+        public ThisEscapeNoEscapes() {
+            this.noLeak1();                             // invoked method is private
+            this.noLeak2();                             // invoked method is final
+            ThisEscapeNoEscapes.noLeak3();              // invoked method is static
+            this.noLeak4(this);                         // parameter is 'this' but it's not leaked
+            this.noLeak5(new ThisEscapeNoEscapes(0));   // parameter is not 'this', so no leak
+            this.noLeak6(null, this, null);             // method leaks 1st and 3rd parameters only
+            this.noLeak7();                             // method does complicated stuff but doesn't leak
+            Runnable r1 = () -> {                       // lambda does not leak 'this'
+                if (System.out == System.err)
+                    throw new RuntimeException();
+            };
+            System.out.println(r1);                     // lambda does not leak 'this'
+            Runnable r2 = () -> {                       // lambda leaks 'this' but is never used
+                this.mightLeak1();
+            };
+            Runnable r3 = this::mightLeak1;             // reference leaks 'this' but is never used
+        }
+
+        public ThisEscapeNoEscapes(int x) {
+        }
+
+        public void mightLeak1() {
+        }
+
+        private void noLeak1() {
+        }
+
+        public final void noLeak2() {
+        }
+
+        public static void noLeak3() {
+        }
+
+        public static void noLeak4(ThisEscapeNoEscapes param) {
+            param.noLeak1();
+            param.noLeak2();
+        }
+
+        public final void noLeak5(ThisEscapeNoEscapes param) {
+            param.mightLeak1();
+        }
+
+        public final void noLeak6(ThisEscapeNoEscapes param1,
+            ThisEscapeNoEscapes param2, ThisEscapeNoEscapes param3) {
+            if (param1 != null)
+                param1.mightLeak1();
+            if (param2 != null)
+                param2.noLeak2();
+            if (param3 != null)
+                param3.mightLeak1();
+        }
+
+        public final void noLeak7() {
+            ((ThisEscapeNoEscapes)(Object)this).noLeak2();
+            final ThisEscapeNoEscapes obj1 = switch (new Object().hashCode()) {
+                case 1, 2, 3 -> null;
+                default -> new ThisEscapeNoEscapes(0);
+            };
+            obj1.mightLeak1();
+        }
+
+    // PrivateClass
+
+        private static class PrivateClass {
+
+            PrivateClass() {
+                this.cantLeak();                    // method is inside a private class
+            }
+
+            public void cantLeak() {
+            }
+        }
+
+    // FinalClass
+
+        public static final class FinalClass extends ThisEscapeNoEscapes {
+
+            public FinalClass() {
+                this.mightLeak1();                  // class and therefore method is final
+            }
+        }
+
+        public static void main(String[] args) {
+            new ThisEscapeNoEscapes();
+        }
+    }
+
+    // Verify 'this' escape detection doesn't warn for sealed classes with local permits
+    public static sealed class ThisEscapeSealed permits ThisEscapeSealed.Sub1, ThisEscapeSealed.Sub2 {
+
+        public ThisEscapeSealed() {
+            this.mightLeak();
+        }
+
+        public void mightLeak() {
+        }
+
+        public static final class Sub1 extends ThisEscapeSealed {
+        }
+
+        public static final class Sub2 extends ThisEscapeSealed {
+        }
+    }
+}

test/langtools/tools/javac/warnings/ThisEscape.out

@@ -0,0 +1,26 @@
+ThisEscape.java:17:60: compiler.warn.possible.this.escape
+ThisEscape.java:28:27: compiler.warn.possible.this.escape
+ThisEscape.java:39:37: compiler.warn.possible.this.escape
+ThisEscape.java:120:17: compiler.warn.possible.this.escape
+ThisEscape.java:133:27: compiler.warn.possible.this.escape.location
+ThisEscape.java:126:17: compiler.warn.possible.this.escape
+ThisEscape.java:133:27: compiler.warn.possible.this.escape.location
+ThisEscape.java:143:51: compiler.warn.possible.this.escape
+ThisEscape.java:145:51: compiler.warn.possible.this.escape
+ThisEscape.java:163:32: compiler.warn.possible.this.escape
+ThisEscape.java:183:35: compiler.warn.possible.this.escape
+ThisEscape.java:195:13: compiler.warn.possible.this.escape
+ThisEscape.java:204:51: compiler.warn.possible.this.escape.location
+ThisEscape.java:224:39: compiler.warn.possible.this.escape
+ThisEscape.java:228:25: compiler.warn.possible.this.escape.location
+ThisEscape.java:237:27: compiler.warn.possible.this.escape
+ThisEscape.java:261:28: compiler.warn.possible.this.escape
+ThisEscape.java:276:28: compiler.warn.possible.this.escape
+ThisEscape.java:300:28: compiler.warn.possible.this.escape
+ThisEscape.java:369:52: compiler.warn.possible.this.escape
+ThisEscape.java:385:17: compiler.warn.possible.this.escape
+ThisEscape.java:396:17: compiler.warn.possible.this.escape
+ThisEscape.java:401:30: compiler.warn.possible.this.escape.location
+ThisEscape.java:444:28: compiler.warn.possible.this.escape
+ThisEscape.java:473:27: compiler.warn.possible.this.escape
+25 warnings