Re: [Patch, fortran] PR121972 - [PDT] Fix for the pdt_86 leak.

On 6/23/26 3:00 AM, Paul Richard Thomas wrote:
> Hello Jerry and Harald,
> 
> The patch does what it says on the box and regression tests correctly.

Except for one very important detail. Its fixing the leak in pdt_82 not pdt_86.

One of the last things I do before getting ready to push a fix is check to see 
if the original problem is fixed. So, I dutifully was checking to make sure the 
pdt_86 leak was fixed. It wasn't. That sent me into a time warp. Went back to my 
notes, oops, I did it again. (A famous song by Brittany Spears)

See below.

> 
> Concerning, Haralds suggestion: I don't see any problem in principle,
> as long as it is recognised that both calls to has_class_alloc_comp
> are negated and so types with class pointer components get through the
> gate. gfc_deallocate_alloc_comp_no_caf should ignore them but I
> haven't checked.
> 
> In chunks 2 and 3, please move expr->ts.type == BT_DERIVED to the
> start of the condition to guard the use of the typespec derived field
> in the call to has_class_alloc_comp. It should be OK as it is but it
> is worthwhile taking that extra little bit of care :-)

Done

> 
> Finally, the leaking part of pdt_86.f03 has been isolated as an
> additional test. If you think that it is useful, please add it to the
> patch. (Renamed to pdt_86_leak_test.f90?)

This comment not applicable. I do have a new test case for the actual leaker in 
the patch.

I will commit shortly.

Thanks for reviews and patience.

Jerry

> 
> OK for mainline and backporting.
> 
> Cheers
> 
> Paul
> 
> On Tue, 23 Jun 2026 at 00:05, Jerry D <[email protected]> wrote:
>>
>> On 6/22/26 1:35 PM, Harald Anlauf wrote:
>>> Hi Jerry!
>>>
>>> Am 22.06.26 um 8:37 PM schrieb Jerry D:
>>>> See attached patch.
>>>>
>>>> Regression tested on x86_64.
>>>>
>>>> A new test case is added to asan to catch this in the future.
>>>
>>> I'd rather leave the review to Paul, but I have one question:
>>> As is, the new helper has_class_alloc_comp might return true for
>>> pointer components, but I think it should not.
>>>
>>> Can you please check?
>>>
>>
>> Harald, I think you are right. I changed it to this:
>>
>> static bool
>> has_class_alloc_comp (gfc_symbol *der)
>> {
>>     for (gfc_component *c = der->components; c; c = c->next)
>>       if (c->ts.type == BT_CLASS && !c->attr.pointer)
>>         return true;
>>     return false;
>> }
>>
>> I will wait for Paul to review.
>>
>> Thanks..
>>
>>
>>
>>
>>> Cheers,
>>> Harald
>>>
>>>> OK for mainline.
>>>>
>>>> Regards,
>>>>
>>>> Jerry
>>>> ---
>>>> fortran: Fix memory leak for array structure-constructor element [PR121972]
>>>>
>>>> Fix the remaining leak in pdt_86.f03. Added a new test in asan to avoid it.
>>>>
>>>>     PR fortran/121972
>>>>
>>>> gcc/fortran/ChangeLog:
>>>>
>>>>     * trans-array.cc (has_class_alloc_comp): New helper; returns true if
>>>>     derived type DER has any CLASS component.
>>>>     (gfc_trans_array_ctor_element): Also free allocatable components when
>>>>     the element expression is EXPR_STRUCTURE, skipping types that contain
>>>>     CLASS components to avoid freeing stack-allocated _data pointers.
>>>>     (gfc_constructor_is_owned_alloc_comp): Likewise treat EXPR_STRUCTURE
>>>>     elements as owned only when the derived type has no CLASS components.
>>>>     * trans-expr.cc (gfc_trans_alloc_subarray_assign): Free allocatable
>>>>     components of the component's temporary descriptor before nulling its
>>>>     data pointer, for non-variable source expressions.
>>>>
>>>> gcc/testsuite/ChangeLog:
>>>>
>>>>     * gfortran.dg/class_array_15.f03: Adjust expected free count.
>>>>     * gfortran.dg/derived_constructor_comps_6.f90: Adjust expected free count.
>>>>     * gfortran.dg/asan/structure_constructor_alloc_comp_leak_1.f90: New test.
>>>> ---
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>