Package, import and type declarations are allowed now in module-info.java by spec

[Georgiy Rakov]

Hello,

current spec [1] now contains following assertions related to grammar:

    A compilation unit (JLS 7.3) may contain a module declaration, in
    which case the filename of the compilation unit is typically
    |module-info.java|.

    CompilationUnit:
       [PackageDeclaration] {ImportDeclaration} {TypeDeclaration}
       ModuleDeclaration

These assertions allows to specify any of import, package or type 
declarations in any compilation unit, for instance module-info.java is 
allowed to contain any of the mentioned declarations. However currently 
javac in the latest jigsaw build [2] reports an error on such cases 
provided they are compiled in module mode. For example if we have 
following directory structure:

    mod\module-info.java:
    module mod {
         exports pkg;
    }

    mod\pkg\module-info.java:
    package pkg;

    class C {
    }

then compiling it by following command line with javac from [2]:

    javac -modulesourcepath . mod\module-info.java mod\pkg\module-info.java

causes following output:

    mod\pkg\module-info.java:1: error: expected 'module'
    package pkg;
    ^
    1 error

The minimized testcase is attached; in order to run it please:

1. Unzip the attached archive to some dir on Windows machined, say 
directory A;
2. Rename A\test\test_bat to A\test\test.bat;
3. Modify test.bat by changing JDK_HOME variable to point to your jigsaw 
JDK 9 installation directory;
4. Run test.bat.

It seems to me either spec or implementation issue, could you please 
tell if you agree.

[1] http://cr.openjdk.java.net/~mr/jigsaw/spec/lang-vm.html
[2] 
http://download.java.net/java/jigsaw/archive/106/binaries/jigsaw-jdk-9-ea+106_windows-x86_bin.zip

Thanks,
Georgiy.