DYLD_FALLBACK_LIBRARY_PATH changed in OpenJDK (was Re: How to load dylib on Mac?)

[Weijun Wang]

Hi All

I've found something new.

It seems the dlopen() function in Mac is quite normal, but there are
some problem inside OpenJDK.

I'm calling dlopen("libkrb5.dylib", RTLD_NOW) inside OpenJDK now and it
returns NULL. However, if I manually set DYLD_LIBRARY_PATH or
DYLD_FALLBACK_LIBRARY_PATH to /usr/lib, then it works.

So I printf the DYLD_FALLBACK_LIBRARY_PATH value, it is changed to
something like jre/lib/i386:jre/lib:jre/../lib/i386. According to Apple
doc, the default value of it should ~/lib:/usr/lib:/usr/local/lib. If
OpenJDK wants to change it to something else, shouldn't it append the
new value onto the old one?

So I suggest making these changes:

--- a/src/solaris/bin/java_md.c
+++ b/src/solaris/bin/java_md.c
@@ -443,6 +443,9 @@
        * variable.
        */
       runpath = getenv(LD_LIBRARY_PATH);
+#ifdef __APPLE__
+      if (!runpath) runpath = "/usr/local/lib:/usr/lib";
+#endif
 #endif /* __solaris__ */

 #if defined(__linux__) || defined(_ALLBSD_SOURCE)

Yes, the default runpath should also include "~/lib", omitted here for
brevity.

Thanks
Max


Max (Weijun) Wang wrote:
> Hi All
> 
> I'm totally new to C programming on Mac.
> 
> On other systems I can call dlopen("libkrb5.so", RTLD_NOW) to return a  
> non-NULL pointer to the library. However, on Mac,  
> dlopen("libkrb5.dylib", RTLD_NOW) returns NULL even if I can see the / 
> usr/lib/libkrb5.dylib is right there. What's wrong here?
> 
> Also, is there a way to write a cross-platform call? Say,  
> dlopen_smart("krb5")?

I've found the JNI_LIB_NAME() macro. Nice.

> 
> Thanks
> Max
> 
>