If you forget to say NO_DOCS=true, the javadoc commands will fail on windows.
On some systems, the javadoc command may run into memory issues, or run very very slowly, but in general this either should work, or the makefiles should explicitly rule out running javadoc on windows, or on machines not capable of running javadoc.

Java RE and integrators, often only run javadoc on one machine, i.e. they set NO_DOCS=true on all but one machine because it takes so long to run javadoc. It would be better if all builds did javadoc, and it ran reasonable well. But that's a different CR.

NOTE: Even if you fix the ; issue below (the source path needs to be in quotes because of the windows ; char), there may be a command line length issue too. Windows command lines longer than 255 are bad news. The command line args should probably be put into a file, say 'args', and the 'javadoc @args' feature should be used.

>>>Recursively making docs docs @ Sat May 8 17:03:40 PDT 2010 ...
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[3]: Entering directory `C:/temp/jprt/P1/B/200513.ohair/source/j2se/make/docs'
rm -f -r C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/docs/api
C:/MKS/mksnt/mkdir -p C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/docs/api
C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/bin/javadoc -J-client -J-Xmx256m -J-Xms128m -source 1.5 -quiet -use -keywords -J-Xms32M -J-Xmx384M -tag beaninfo:X -tag revised:X -tag since.unbundled:X -tag spec:X -tag Note:X -tag ToDo:X -tag 'jl3:a:See <cite><a href="http://java.sun.com/docs/books/jls/"> The Java Language Specification, Third Edition</a></cite>:' -encoding ISO-8859-1 -splitIndex -doctitle 'Java&#x2122; Platform, Standard Edition 6<br>API Specification''<br><b>DRAFT&nbsp;'internal-b00'</b>' -windowtitle 'Java Platform SE 6'" b00" -header '<b>Java&#x2122;&nbsp;Platform<br>Standard&nbsp;Ed.&nbsp;6</b>''<br><b>DRAFT&nbsp;'internal-b00'</b>' -top '<div style="background-color: #EEEEEE"> <div style="padding: 6px; margin-top: 2px; margin-bottom: 6px; margin-left: 6px; margin-right: 6px; text-align: justify; font-size: 80%; font-family: Helvetica, Arial, sans-serif; font-weight: normal;"> Please note that the specifications and other information contained herein are not final and are subject to change. The information is being made available to you solely for purpose of evaluation. </div> </div>' -bottom '<font size="-1"> <a href="http://bugs.sun.com/services/bugreport/index.jsp">Submit a bug or feature</a><p> <a href="{@docroot}/../legal/cpyr.html">Copyright</a> &#x00a9; 1993, 2010, Oracle and/or its affiliates. All rights reserved. </font>' -overview ../../src/share/classes/overview-core.html \
                   -d C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/docs/api \
                   -sourcepath ../../src/share/classes;../../src/windows/classes;C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/gensrc;../../src/share/doc/stub \
                   java.applet java.awt java.awt.color java.awt.datatransfer java.awt.dnd java.awt.event java.awt.font java.awt.geom java.awt.im java.awt.im.spi java.awt.image java.awt.image.renderable java.awt.print java.beans java.beans.beancontext java.io java.lang java.lang.annotation java.lang.instrument java.lang.management java.lang.ref java.lang.reflect java.math java.net java.nio java.nio.channels java.nio.channels.spi java.nio.charset java.nio.charset.spi java.rmi java.rmi.activation java.rmi.dgc java.rmi.registry java.rmi.server java.security java.security.acl java.security.cert java.security.interfaces java.security.spec java.sql java.text java.text.spi java.util java.util.concurrent java.util.concurrent.atomic java.util.concurrent.locks java.util.jar java.util.logging java.util.prefs java.util.regex java.util.spi java.util.zip javax.accessibility javax.activation javax.activity javax.annotation javax.annotation.processing javax.crypto javax.crypto.interfaces javax.crypto.spec javax.imageio javax.imageio.event javax.imageio.metadata javax.imageio.plugins.jpeg javax.imageio.plugins.bmp javax.imageio.spi javax.imageio.stream javax.jws javax.jws.soap javax.lang.model javax.lang.model.element javax.lang.model.type javax.lang.model.util javax.management javax.management.loading javax.management.monitor javax.management.relation javax.management.openmbean javax.management.timer javax.management.modelmbean javax.management.remote javax.management.remote.rmi javax.naming javax.naming.directory javax.naming.event javax.naming.ldap javax.naming.spi javax.net javax.net.ssl javax.print javax.print.attribute javax.print.attribute.standard javax.print.event javax.rmi javax.rmi.CORBA javax.rmi.ssl javax.script javax.security.auth javax.security.auth.callback javax.security.auth.kerberos javax.security.auth.login javax.security.auth.spi javax.security.auth.x500 javax.security.cert javax.security.sasl javax.sound.sampled javax.sound.sampled.spi javax.sound.midi javax.sound.midi.spi javax.sql javax.sql.rowset javax.sql.rowset.serial javax.sql.rowset.spi javax.swing javax.swing.border javax.swing.colorchooser javax.swing.filechooser javax.swing.event javax.swing.table javax.swing.text javax.swing.text.html javax.swing.text.html.parser javax.swing.text.rtf javax.swing.tree javax.swing.undo javax.swing.plaf javax.swing.plaf.basic javax.swing.plaf.metal javax.swing.plaf.multi javax.swing.plaf.synth javax.tools javax.transaction javax.transaction.xa javax.xml.parsers javax.xml.bind javax.xml.bind.annotation javax.xml.bind.annotation.adapters javax.xml.bind.attachment javax.xml.bind.helpers javax.xml.bind.util javax.xml.soap javax.xml.ws javax.xml.ws.handler javax.xml.ws.handler.soap javax.xml.ws.http javax.xml.ws.soap javax.xml.ws.spi javax.xml.ws.wsaddressing javax.xml.transform javax.xml.transform.sax javax.xml.transform.dom javax.xml.transform.stax javax.xml.transform.stream javax.xml javax.xml.crypto javax.xml.crypto.dom javax.xml.crypto.dsig javax.xml.crypto.dsig.dom javax.xml.crypto.dsig.keyinfo javax.xml.crypto.dsig.spec javax.xml.datatype javax.xml.validation javax.xml.namespace javax.xml.xpath javax.xml.stream javax.xml.stream.events javax.xml.stream.util org.ietf.jgss org.omg.CORBA org.omg.CORBA.DynAnyPackage org.omg.CORBA.ORBPackage org.omg.CORBA.TypeCodePackage org.omg.stub.java.rmi org.omg.CORBA.portable org.omg.CORBA_2_3 org.omg.CORBA_2_3.portable org.omg.CosNaming org.omg.CosNaming.NamingContextExtPackage org.omg.CosNaming.NamingContextPackage org.omg.SendingContext org.omg.PortableServer org.omg.PortableServer.CurrentPackage org.omg.PortableServer.POAPackage org.omg.PortableServer.POAManagerPackage org.omg.PortableServer.ServantLocatorPackage org.omg.PortableServer.portable org.omg.PortableInterceptor org.omg.PortableInterceptor.ORBInitInfoPackage org.omg.Messaging org.omg.IOP org.omg.IOP.CodecFactoryPackage org.omg.IOP.CodecPackage org.omg.Dynamic org.omg.DynamicAny org.omg.DynamicAny.DynAnyPackage org.omg.DynamicAny.DynAnyFactoryPackage org.w3c.dom org.w3c.dom.events org.w3c.dom.bootstrap org.w3c.dom.ls org.xml.sax org.xml.sax.ext org.xml.sax.helpers
javadoc: error - No packages or classes specified.
usage: javadoc [options] [packagenames] [sourcefiles] [@files]
-overview <file> Read overview documentation from HTML file
-public Show only public classes and members
-protected Show protected/public classes and members (default)
-package Show package/protected/public classes and members
-private Show all classes and members
-help Display command line options and exit
-doclet <class> Generate output via alternate doclet
-docletpath <path> Specify where to find doclet class files
-sourcepath <pathlist> Specify where to find source files
-classpath <pathlist> Specify where to find user class files
-exclude <pkglist> Specify a list of packages to exclude
-subpackages <subpkglist> Specify subpackages to recursively load
-breakiterator Compute 1st sentence with BreakIterator
-bootclasspath <pathlist> Override location of class files loaded
by the bootstrap class loader
-source <release> Provide source compatibility with specified release
-extdirs <dirlist> Override location of installed extensions
-verbose Output messages about what Javadoc is doing
-locale <name> Locale to be used, e.g. en_US or en_US_WIN
-encoding <name> Source file encoding name
-quiet Do not display status messages
-J<flag> Pass <flag> directly to the runtime system

Provided by Standard doclet:
-d <directory> Destination directory for output files
-use Create class and package usage pages
-version Include @version paragraphs
-author Include @author paragraphs
-docfilessubdirs Recursively copy doc-file subdirectories
-splitindex Split index into one file per letter
-windowtitle <text> Browser window title for the documenation
-doctitle <html-code> Include title for the overview page
-header <html-code> Include header text for each page
-footer <html-code> Include footer text for each page
-top <html-code> Include top text for each page
-bottom <html-code> Include bottom text for each page
-link <url> Create links to javadoc output at <url>
-linkoffline <url> <url2> Link to docs at <url> using package list at <url2>
-excludedocfilessubdir <name1>:.. Exclude any doc-files subdirectories with given name.
-group <name> <p1>:<p2>.. Group specified packages together in overview page
-nocomment Supress description and tags, generate only declarations.
-nodeprecated Do not include @deprecated information
-noqualifier <name1>:<name2>:... Exclude the list of qualifiers from the output.
-nosince Do not include @since information
-notimestamp Do not include hidden time stamp
-nodeprecatedlist Do not generate deprecated list
-notree Do not generate class hierarchy
-noindex Do not generate index
-nohelp Do not generate help link
-nonavbar Do not generate navigation bar
-serialwarn Generate warning about @serial tag
-tag <name>:<locations>:<header> Specify single argument custom tags
-taglet The fully qualified name of Taglet to register
-tagletpath The path to Taglets
-charset <charset> Charset for cross-platform viewing of generated documentation.
-helpfile <file> Include file that help link links to
-linksource Generate source in HTML
-sourcetab <tab length> Specify the number of spaces each tab takes up in the source
-keywords Include HTML meta tags with package, class and member info
-stylesheetfile <path> File to change style of the generated documentation
-docencoding <name> Output encoding name
1 error
../../src/windows/classes: not found
C:/temp/jprt/P1/B/200513~1.OHA/source/control/build/WINDOW~2/gensrc: not found
../../src/share/doc/stub: not found
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[3]: *** [coredocs] Error 127
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[3]: Leaving directory `C:/temp/jprt/P1/B/200513.ohair/source/j2se/make/docs'
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[2]: *** [docs] Error 1
C:\jprt\slashjava\devtools\win32\bin\gnumake.exe[2]: Leaving directory `C:/temp/jprt/P1/B/200513.ohair/source/j2se/make'
gnumake.exe[1]: *** [j2se-build] Error 2