Trouble compiling swt.jar

I'm trying to compile swt.jar to swt.o so that I can make a native
Windows executable from Java source that uses SWT (3.1.1) as the
windowing toolkit.  When I try:
gcj -c swt.jar
I get several verification errors:

org/eclipse/swt/dnd/HTMLTransfer.java: In class
'org.eclipse.swt.dnd.HTMLTransfer':
org/eclipse/swt/dnd/HTMLTransfer.java: In method
'org.eclipse.swt.dnd.HTMLTransfer.nativeToJava(org.eclipse.swt.dnd.TransferData)':
org/eclipse/swt/dnd/HTMLTransfer.java:92: error: verification error at
PC=201
org/eclipse/swt/dnd/HTMLTransfer.java:92: error: might transfer control
into subroutine
org/eclipse/swt/dnd/RTFTransfer.java: In class
'org.eclipse.swt.dnd.RTFTransfer':
org/eclipse/swt/dnd/RTFTransfer.java: In method
'org.eclipse.swt.dnd.RTFTransfer.nativeToJava(org.eclipse.swt.dnd.TransferData)':
org/eclipse/swt/dnd/RTFTransfer.java:92: error: verification error at PC=201
org/eclipse/swt/dnd/RTFTransfer.java:92: error: might transfer control
into subroutine
org/eclipse/swt/dnd/TextTransfer.java: In class
'org.eclipse.swt.dnd.TextTransfer':
org/eclipse/swt/dnd/TextTransfer.java: In method
'org.eclipse.swt.dnd.TextTransfer.nativeToJava(org.eclipse.swt.dnd.TransferData)':
org/eclipse/swt/dnd/TextTransfer.java:114: error: verification error at
PC=377
org/eclipse/swt/dnd/TextTransfer.java:114: error: might transfer control
into subroutine
org/eclipse/swt/dnd/URLTransfer.java: In class
'org.eclipse.swt.dnd.URLTransfer':
org/eclipse/swt/dnd/URLTransfer.java: In method
'org.eclipse.swt.dnd.URLTransfer.nativeToJava(org.eclipse.swt.dnd.TransferData)':
org/eclipse/swt/dnd/URLTransfer.java:98: error: verification error at PC=208
org/eclipse/swt/dnd/URLTransfer.java:98: error: might transfer control
into subroutine
org/eclipse/swt/graphics/ImageLoader.java: In class
'org.eclipse.swt.graphics.ImageLoader':
org/eclipse/swt/graphics/ImageLoader.java: In method
'org.eclipse.swt.graphics.ImageLoader.load(java.lang.String)':
org/eclipse/swt/graphics/ImageLoader.java:149: error: verification error
at PC=40
org/eclipse/swt/graphics/ImageLoader.java:149: error: label part of
different subroutines
org/eclipse/swt/ole/win32/OleClientSite.java: In class
'org.eclipse.swt.ole.win32.OleClientSite':
org/eclipse/swt/ole/win32/OleClientSite.java: In method
'org.eclipse.swt.ole.win32.OleClientSite.saveToStorageFile(java.io.File)':
org/eclipse/swt/ole/win32/OleClientSite.java:1164: error: verification
error at PC=182
org/eclipse/swt/ole/win32/OleClientSite.java:1164: error: might transfer
control into subroutine

The version of gcj in use is:
$ gcj --version
gcj.exe (GCC) 4.0.2

Which I found on the thisiscool.com site.  I'm running Windows XP SP2
with cygwin.  Anybody have any ideas what I'm doing wrong?