[Cs-studio-core] Eclipse 4 basically required because of Java 7 and Mac OS X

[Kasemir, K. <kas...@or...>]

Hi:

One more reason to move to Eclipse 4.x (with 3.x compatibility layer) is
its Java 7 support on Mac OS X.

Recent CSS source code updates require Java 7.
But on Mac OS X it's hard to get Java 7 to work with an Eclipse 3.7 target.
When starting the Eclipse 4.2.1 IDE, it will by default locate Java 7 and
use it.
When starting the Eclipse 3.7.2 IDE, it will use Java 6.
Same with CSS for the 3.x target platform.
The Eclipse 3.7 launcher will always end up with a Java 6 runtime, and
then of course CSS won't run.

Even if you start with Java 7 in your PATH, even if you explicitly try

 css.app/Contents/MacOS/css -vm
/Library/Java/JavaVirtualMachines/jdk1.7.0_13.jdk/Contents/Home/bin/java

or put the corresponding -vm args into the *.ini file, the launcher will
instead start with 
java.version=1.6.0_37
java.vendor=Apple Inc.
and then obviously end with errors like org.epics.vtype ..
Bundle-RequiredExecutionEnvironment: JavaSE-1.7



The only solution I found is to circumvent the launcher like this

# Set PATH to get java 7, then
java -showversion -XX:MaxPermSize=256m -Xms1024m -Xmx1024m \
 -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts \
 -Xdock:icon=css.app/Contents/Resources/css.icns \
 -Dosgi.requiredJavaVersion=1.7 \
 -jar plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar

(described on 
http://stackoverflow.com/questions/10352715/how-do-i-run-eclipse-using-orac
les-new-1-7-jdk-for-the-mac)



In addition, CSS for Mac OS X must be built for x86_64, because Oracle
Java 7 for Mac OS X is 64-bit only.

Thanks,
Kay