> We just discovered that every symbol is libjvm is being exported on OSX. The
> OSX/BSD makefiles were copied from the linux ones and so have the options for
> linker scripts and mapfiles, but as OSX doesn't support linker scripts this
> is disabled by setting LDNOMAP=true - hence all symbols are exported.
>
> However the OSX linker does support -exported_symbols_list
>
> https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/ld.1.html
>
> so I was wondering why the build wasn't modified to use that so that we only
> export the JVM symbols we intend to export? (That's a question for the
> macosx-port-dev folk :) ).
>
> Does anyone have experience using this such that we can get the hotspot build
> fixed?
Exports should be handled by the visibility settings. Until recently the
JNIEXPORT macro resolved to nothing, now it sets __attribute__(("visibility"
("default))) (at least in 8, that should be backported to 7u if it hasn't
already). The "default" visibility means export that symbol. To hide
non-exported symbols you need to provide --fvisibility=hidden to gcc or clang
when compiling.
Hotspot has it's own jni_md.h headers with macros to determine JNIEXPORT, but
they were wrong last I checked. It appears they attempted to clear the macro if
a certain version of gcc was used, but what happens is it disables it for all
versions of gcc above a particular release (which hasn't been used on Mac is
quite some time). I pointed this out when the JNIEXPORT patch was posted for
review to core-libs-dev (I think...), it was CC'd to the hotspot list too so
someone has to have seen it. I'm not sure if it's been fixed or not.
-DrD-
