Re: can DECL_RESULT be 0?

[Gabriel Dos Reis <gdr@integrable-solutions.net>]

Jim Wilson <wilson@specifix.com> writes:

| Rafael Ávila de Espíndola wrote:
| >  DECL_RESULT holds a RESULT_DECL node for the value of a function,
| >     or it is 0 for a function that returns no value.
| >     (C functions returning void have zero here.)
| 
| I looked at gcc-1.42, and even there, a DECL_RESULT always holds a
| RESULT_DECL.  It can never be zero.  However, the DECL_RTL of this
| RESULT_DECL is zero for a function that returns no value.  I'm not
| sure if this is a typo in the tree.def file, or whether perhaps an
| implementation change was made a very long time ago.  Either way, this
| comment as written is wrong, and has been for a very long time.  We
| could perhaps drop the comment about 0 values, or maybe expand it to
| say that the DECL_RTL of the RESULT_DECL is 0 for functions that
| return no value.  aggregate_value_p doesn't look at DECL_RTL
| (DECL_RESULT (...)) so there is no problem there.

I was under the impression that  the DECL_RESULT is nullified for a
function that passes the named return-value optimization.

-- Gaby