[GOLD] Handle merged input sections in Output_section::get_input_sections()

[Ian Lance Taylor]

"Doug Kwan (關振德)" <dougkwan@google.com> writes:

> The final image does not contain the ELF header and the entry point is
> set to address 0.   The input sections .rodata* are handled by gold as
> merged sections.  They are not exported to the script by
> Output_section::get_input_sections() and are left at the beginning of
> the .text output section when normal input sections are removed.  When
> the script re-inserts the input sections again,  the merged input
> sections are now input beginning .text, where the entry point is
> located.  That causes the output not bootable since the entry point
> contains a string instead of the first instruction.
>
> I am thinking about adding an get_input_sections method to the base
> class of merged sections.  What do you think?   We may optimize for
> speed by not exporting if the output section contains nothing but
> merged input section.

Interesting, this is the exact case I described in the comment saying
that with luck it would never matter.

I don't see how adding a get_input_sections method for merged sections
could do the right thing.  The sections should still be merged, and I
don't see how that could happen if you pull out the input sections.
As far as I can see the only reasonable choice is to also add merge
sections to the list, and to arrange to handle merge sections in the
various callers.

Ian