Error: can't resolve `0' {*UND* section} - `__DTOR_LIST__' {.dtors section}

[Alan Modra]

On Sat, Jul 06, 2019 at 04:55:20PM -0500, William Tambe wrote:
> I have a gcc port that yield the following assembly to negate a
> register by an immediate:
> inc %11, -__DTOR_LIST__
> In the above assembly example, register %11 is to be decremented by
> __DTOR_LIST__ where __DTOR_LIST__ is a label.
> 
> To parse the immediate portion of the above assembly, the
> corresponding gas port use the function parse_exp_save_ilp(); however
> it yields the following error:
> 
> Error: can't resolve `0' {*UND* section} - `__DTOR_LIST__' {.dtors section}
> 
> parse_exp_save_ilp() is not able to evaluate an expression in which
> the negation operator precede a symbol.

The problem isn't there but rather in expecting that a relocatable
assembler should be able to negate a section relative symbol.  To do
that your target must be able to emit relocations that handle
negation of their symbols.

-- 
Alan Modra
Australia Development Lab, IBM