Re: [Patch,avr]: Fix wrong warning PR59396

[Georg-Johann Lay <avr at gjlay dot de>]

Am 12/18/2013 12:37 PM, schrieb Richard Biener:
> On Tue, Dec 17, 2013 at 2:05 PM, Georg-Johann Lay <avr@gjlay.de> wrote:
> > Am 12/05/2013 04:09 PM, schrieb Richard Biener:
> > > On Thu, Dec 5, 2013 at 3:53 PM, Georg-Johann Lay <avr@gjlay.de> wrote:
> > >
> > > > This is a fix of a wrong warning for a bas ISR name.  The assumption was
> > > > that if DECL_ASSEMBLER_NAME is set, it would always starts with a *.
> > > >
> > > > This is not the case for LTO compiler where the assembler name is the
> > > > plain
> > > > name of the function (except an assembler name is set).
> > >
> > >
> > > That sounds odd to me.  Does the bug reproduce with -fwhole-program?
> > > Or if the interrupt handler is static?
> >
> >
> > Hi, I tried to debug lto1.
> >
> > What I see is that SET_DECL_ASSEMBLER_NAME with "__vector_14", i.e. without
> > a leading '*', is called from
> >
> > tree-streamer-in.c:lto_input_ts_decl_with_vis_tree_pointers().
> >
> > Hope that helps in narrowing down the issue.
>
> You need to debug the LTO IL creating process (cc1) then - this code merely
> restores what the compile-stage assigned the assembler name to.  See
> tree.c:assign_assembler_name_if_needed.
>
> Richard.

Seems that assembler_name is not only used for names set with asm() but also 
(ab)used in many other occasions like C++ or setting the name of libgcc 
function calls.

The easiest and least intrusive fix is still in the avr backend as proposed in

http://gcc.gnu.org/ml/gcc-patches/2013-12/msg00529.html

in particular because the assembler_name bits are not well documented, e.g. in 
tree.h.

Or do you know an other way to fix this without any side effects on other 
target / languages?


Johann


> > > > Thus, do a more restrictive test if the first character of the function
> > > > name
> > > > has to be skipped.
> > > >
> > > > Ok to commit?
> > > >
> > > > Johann
> > > >
> > > >           PR target/59396
> > > >           * config/avr/avr.c (avr_set_current_function): If the first char
> > > >           of the function name is skipped, make sure it is actually '*'.