ld-related bug in LTTng

[Martin Ünsal]

On Thu, May 1, 2014 at 4:23 PM, Alan Modra <amodra@gmail.com> wrote:
> Is gcc emitting the reference to __start___tracepoints_ptrs as hidden?
> (Look at an object with readelf -s to see)

Aha! No, it isn't.

With GCC 4.6.4 the symbol is correctly emitted as hidden visibility:

$ arm-linux-gnueabi-readelf -s pmtrace_bundle_provider.o | grep __start_
   153: 00000000     0 NOTYPE  WEAK   HIDDEN   UND __start___tracepoints_ptr

With GCC 4.7.2 the symbol is incorrectly emitted as default visibility:

$ arm-linux-gnueabi-readelf -s pmtrace_bundle_provider.o | grep __start_
   144: 00000000     0 NOTYPE  WEAK   DEFAULT  UND __start___tracepoints_ptr

Here is the declaration:

extern struct tracepoint * const __start___tracepoints_ptrs[]
__attribute__((weak, visibility("hidden")));

This looks like it is clearly a compiler issue. I will take this back
to gcc-help mailing list.

Thanks for the help,
Martin