Question

I am trying to compile a code base using ant and the javac 1.7 compiler.
Currently, the code base compiles using the 1.6 compiler but when I switch to the 1.7 compiler, I get the following two oddities.

1) I get a warning: “warning: x is internal proprietary API and may be removed in a future release” where x is part of an internal proprietary API yet the line in the code it references does not reference x (nor does it reference x anywhere in the given file). This happened in a few places and the line it references is in a comment block.

2) The compile terminates with the following:

[javac] The system is out of resources.
[javac] Consult the following stack trace for details.
[javac] java.lang.StackOverflowError
[javac]     at com.sun.tools.javac.comp.Attr.attribTree(Attr.java:418)
[javac]     at com.sun.tools.javac.comp.Attr.attribExpr(Attr.java:460)
[javac]     at com.sun.tools.javac.comp.Attr.visitBinary(Attr.java:2053)
[javac]     at com.sun.tools.javac.tree.JCTree$JCBinary.accept(JCTree.java:1565)

The relevant parameters that are in my ant script for javac are:

      source="1.6" 
        target="1.6" 
        debug="on" 
        debuglevel="lines,vars,source" 
        nowarn="on" 
        fork="yes" 
        executable="C:\Program Files\Java\jdk1.7.0_04\bin\javac"
        memorymaximumsize="1500m"

I tried changing the source and target versions. I also tried ajusting the memory size. It does not seem to help.

Answer 1

(Just copying my comment to an answer, in case it turns out to be the answer.)

This may well be a Java 7 compiler bug. You can however give the compiler more memory by running javac with an argument like -Xss16M. This makes the thread stack size 16MB vs default of 1MB. It may be a viable workaround.

The message about internal APIs is unrelated and can be ignored.