I’ve just installed Spoofax Nightly (from http://download.spoofax.org/update/nightly/) in a fresh downloaded copy of the latest Eclipse (Eclipse Standard 4.4 32-bit on Windows), and I’ve setup the eclipse.ini file like this:

-startup
plugins/org.eclipse.equinox.launcher_1.3.0.v20140415-2008.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.200.v20140603-1326
-product
org.eclipse.epp.package.standard.product
--launcher.defaultAction
openFile
--launcher.XXMaxPermSize
256M
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
--launcher.appendVmargs
-vmargs
-Dosgi.requiredJavaVersion=1.7
-Xss8m
-Xms256m
-Xmx1024m
-XX:MaxPermSize=256m
-server
-Djava.net.preferIPv4Stack=true

However, Spoofax gives a warning on start-up:

Spoofax needs Eclipse to be started with (can be set in eclipse.ini):
-vmargs -server -Xmx1024m -Xss8m

The following options are currently missing:
-server

Submitted by D. Pelsmaeker on 11 July 2014 at 17:17

There is no 32 bit server VM, install the 64 version.

I have 64 bit version, but still get this warning.

@Gabriël: Does this mean Spoofax requires a 64 bit VM? If so, the installation instructions are not clear about it.

I switched to the 64-bit Eclipse, and the warning indeed went away.

Ignore my previous comments. The warning did only show up in my second Eclipse instance because I forgot to set the vmargs in my run configuration.

@Gabriël: I guess we should just add to the download page that users should install 64 bit JRE and 64 bit Eclipse. And if server VM is default for 64 bit like you said, then we can remove this argument and maybe change the warning message to “install 64 bit JRE and 64 bit Eclipse”.

Seems like Server VM is possible with 32 bit too though:

Windows:

-vm [your JRE path]\bin\server\jvm.dll 

Linux:

-vm [your_jdk_folder]/jre/lib/i386/client/libjvm.so

So the 32-bit Java has a server VM, but it is not used when passing the -server argument? Wierd.

I did some more reading and the server VM is activated by default only on ‘server-grade machines’, but there is no specification or explanation what a server-grade machine is. So we should recommend people to install a 64-bit VM for optimal performance. The warning in Spoofax should make clear that -server is not required but recommended, and if a 32 bit VM is detected the warning should recommend installing a 64-bit VM.