Re: Behavior change of driver on multiple input assembly files

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Sun, Jan 2, 2011 at 2:05 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Sun, Jan 2, 2011 at 1:18 PM, Ian Lance Taylor <iant@google.com> wrote:
>> Richard Guenther <richard.guenther@gmail.com> writes:
>>
>>> On Sun, Jan 2, 2011 at 9:24 PM, Ian Lance Taylor <iant@google.com> wrote:
>>>> Richard Guenther <richard.guenther@gmail.com> writes:
>>>>
>>>>> Your small patch removing have_o || is ok I guess.
>>>>
>>>> Wait. ?That will change the behaviour of
>>>> ? ?gcc -o foo.o -c f1.c f2.c f3.c
>>>> Is that what we want?
>>>
>>> Does it? ?I don't think so. ?Most of the combine handling was removed by
>>> the patch that caused the regression, so -o and -c doesn't combine anymore
>>> (with multiple sources).
>>
>> Sorry, you're right. ?The difference is that @c has 0 for the combinable
>> field, and @assembler has 1. ?Before H.J.'s change, this worked
>> ? ?gcc -c -o f.o f1.s f2.s
>> After his change, it does not. ?That is probably not a big deal.
>>
>> I wonder why @assembler has 1 for combinable? ?It seems to have been set
>> to 1 when the combinable field was added in 2004-04-05 with -combine.
>> Now that -combine has been removed, if the combinable field for
>> @assembler were 0, it seems to me that H.J.'s problem would also be
>> fixed. ?And it seems to me that it should be 0.
>>
>>
>>>> Also, right now the gccgo driver depends on the -o behaviour to combine
>>>> inputs. ?If that changes, the driver will need to provide some other way
>>>> to let the frontend force inputs to be combined.
>>>
>>> For go it isn't equivalent to do gcgo -c t1.go; gcgo -c t2.go; gcgo t1.o t2.o
>>> compared to gcgo t1.go t2.go?
>>
>> No, it is not. ?All .go input files must be passed to go1 at once.
>> H.J.'s patch has indeed broken gccgo.
>>
>
> Can you try this patch?
>
> Thanks.
>
>
> --
> H.J.
> ---
> diff --git a/gcc/gcc.c b/gcc/gcc.c
> index 0d633a4..d0b2c96 100644
> --- a/gcc/gcc.c
> +++ b/gcc/gcc.c
> @@ -6582,7 +6582,20 @@ warranty; not even for MERCHANTABILITY or FITNESS FOR A P
> ARTICULAR PURPOSE.\n\n"
>
> ? explicit_link_files = XCNEWVEC (char, n_infiles);
>
> + ?/* Check if we should combine inputs. ?*/
> ? combine_inputs = flag_wpa;
> + ?if (!combine_inputs)
> + ? ?for (i = 1; i < decoded_options_count; i++)
> + ? ? ?{
> + ? ? ? if (decoded_options[i].opt_index == OPT_x)
> + ? ? ? ? {
> + ? ? ? ? ? struct compiler *compiler
> + ? ? ? ? ? ? = lookup_compiler (NULL, 0, decoded_options[i].arg);
> + ? ? ? ? ? if (compiler)
> + ? ? ? ? ? ? combine_inputs = compiler->combinable;
> + ? ? ? ? ? break;
> + ? ? ? ? }
> + ? ? ?}
>
> ? for (i = 0; (int) i < n_infiles; i++)
> ? ? {
>

This doesn't work for go since -xgo isn't used with gccgo. Is there
a way to tell what the default language is for a gcc driver?

-- 
H.J.