Undo dynamic symbol state after regular object sym type mismatch

[Alan Modra]

Hi Maciej,

On Tue, Jul 11, 2017 at 02:01:31AM +0100, Maciej W. Rozycki wrote:
>  In an attempt to prevent new MIPS target failures in preparation for the 
> 2.29 release I have now looked into it and what the MIPS backend produces 
> looks correct to me according to the MIPS psABI.
> 
>  Specifically, while linking the `indirect5a' executable, in the 
> `indirect5a.o' object supplied we have a locally-defined global `bar' 
> symbol referred to -- in the case of the o32 ABI -- with an R_MIPS_GOT16 
> relocation, which is absolutely fine for a MIPS SVR4 psABI executable.  
> In response the MIPS backend creates the mandatory global GOT entry and 

That's fine.

> its corresponding dynsym entry for `bar'.

But in my opinion this is a bug.  A symbol in an executable shouldn't
be made dynamic unless it is referenced by a dynamic object, or by
--export-dynamic or other similar options.  Since "bar" in the
executable is a variable and "bar" in the dynamic library a function,
the dynamic library can't be referencing the executable "bar".  The
executable GOT entry for "bar" will need a dynamic relocation in a
PIE, but that can be a relative relocation not needing a symbol.

-- 
Alan Modra
Australia Development Lab, IBM