Re: [testsuite] PATCH: Add check_effective_target_pie

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

On Wed, Feb 11, 2015 at 8:15 AM, Rainer Orth
<ro@cebitec.uni-bielefeld.de> wrote:
> "H.J. Lu" <hjl.tools@gmail.com> writes:
>
>> On Wed, Feb 11, 2015 at 7:19 AM, Rainer Orth
>> <ro@cebitec.uni-bielefeld.de> wrote:
>>> "H.J. Lu" <hjl.tools@gmail.com> writes:
>>>
>>>> On Wed, Feb 11, 2015 at 6:10 AM, Rainer Orth
>>>> <ro@cebitec.uni-bielefeld.de> wrote:
>>>>> "H.J. Lu" <hjl.tools@gmail.com> writes:
>>>>>
>>>>>>> The new proc is bogus, unfortunately: there's already an existing
>>>>>>> check_effective_target_pie that checks if a target can support PIE.  The
>>>>>>> new one just overrides the previous one.  On targets supporting PIE
>>>>>>> (like Darwin), but not defaulting to it, the PIE tests suddenly turn out
>>>>>>> UNSUPPORTED.
>>>>>>>
>>>>>>> You should rename the new one to
>>>>>>> e.g. check_effective_target_pie_default, update the single user, and
>>>>>>> document it in sourcebuild.texi.
>>>>>>
>>>>>> I checked in this as an obvious fix.
>>>>>
>>>>> I think pie_enabled is not a very descriptive name:
>>>>>
>>>>> Index: doc/sourcebuild.texi
>>>>> ===================================================================
>>>>> --- doc/sourcebuild.texi (revision 220617)
>>>>> +++ doc/sourcebuild.texi (working copy)
>>>>> @@ -1884,6 +1884,9 @@
>>>>>  @item nonpic
>>>>>  Target does not generate PIC by default.
>>>>>
>>>>> +@item pie_enabled
>>>>> +Target generates PIE by default.
>>>>> +
>>>>>  @item pcc_bitfield_type_matters
>>>>>  Target defines @code{PCC_BITFIELD_TYPE_MATTERS}.
>>>>>
>>>>> With -fpie, PIE is also enabled, just not the default without any
>>>>
>>>> I was testing
>>>>
>>>> # make RUNTESTFLAGS="--target_board='unix{-m32\ -fpie,-fpie}'
>>>>
>>>> I don't consider PIE is default.  It is just enabled.
>>>>
>>>>> options.  Please either go with the pie_default I sugested or wait for
>>>>> others to weigh in before rushing in another `obvious' fix.
>>>
>>> Then the description (both sourcebuild.texi and target-supports.texi) is
>>> confusing.
>>
>> That is how other options are described.
>
> You're not getting my point:
>
> * target-supports.exp now has
>
> # Return 1 if the current multilib generates PIE by default.
>
> * sourcebuild.texi states
>
> Target generates PIE by default.
>
> Which one is it?

I copied them from nonpic

# Return 1 if the current multilib does not generate PIC by default.

@item nonpic
Target does not generate PIC by default.

>>> What are you trying to achieve here, actually?  Even on Solaris 11/x86
>>> (which doesn't support PIE), -fpie lets the
>>> check_effective_target_pie_enabled (or whatever it's called) proc pass.
>>> Shouldn't it also check if the target can support PIE at all?
>>
>> Assembly outputs may be different, depending on if PIE is
>> enabled nor not. When we scan assembly outputs for test
>> results, we have different expected results when PIE is enabled.
>> That is how pie_enabled is used so far.
>
> But why would you need a new effective-target keyword for that?  Simply
> test the existing { target pie }, add -fpie and scan the assembler
> output.  Why would you need pie_enabled or whatever at all?  Again: what
> are you trying to achieve that cannot be done with the current keyword?
>
> Right now, in gcc.target/i386/pie.c, you're only testing the PIE case
> when PIE has been enabled by some means external to testsuite.  The test
> always comes out UNSUPPORTED if not, so it isn't even exercised in a
> regular bootstrap (except on Darwin which defaults to PIE, I believe).

That is intentional.  gcc.target/i386/pie.c will be test by

1. RUNTESTFLAGS="--target_board='unix{-m32\ -fpie,-fpie}'" .  Or
2. PIE is enabled by default:

https://gcc.gnu.org/ml/gcc-patches/2015-01/msg00956.html


-- 
H.J.