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 3:03 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> 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?
>

I am testing this patch with all languages on Linux/x86-64.


-- 
H.J.
---
gcc/

2011-01-02  H.J. Lu  <hongjiu.lu@intel.com>

	PR driver/47137
	* gcc.c (default_language): New.
	(main): Lookup compiler to check if we should combine inputs.

	* gcc.h (default_language): New.

gcc/go/

2011-01-02  H.J. Lu  <hongjiu.lu@intel.com>

	PR driver/47137
	* gospec.c (lang_specific_driver): Set default_language if
	needed.

Attachment: gcc-pr47137-1.patch
Description: Text document