Hi all,
as preremark I want to note that the testcase class_assign_4.f90
was added for PR83118/PR96012 (fixes problems in handling class objects, Dec
18, 2020)
and got revised for PR99124 (class defined operators, Feb 23, 2021).
Both patches were then also applied to GCC 9 and 10.
On 26.03.21 17:30, Paul Richard Thomas via Gcc-patches wrote:
This patch comes in two versions: submit.diff with Change.Logs or
submit2.diff with Change2.Logs.
The first fixes the problem by changing array temporaries from class
expressions into class temporaries. This permits the use of
gfc_get_class_from_expr to obtain the vptr for these temporaries and all
the good things that come with that when handling dynamic types. The second
part of the fix is to use the array element length from the class
descriptor, when reallocating on assignment. This is needed because the
vptr is being set too early. I will set about trying to track down why this
is happening and fix it after release.
The second version does the same as the first but puts in place a load of
tidying up that is permitted by the fix to class array temporaries.
I couldn't readily see how to prepare a testcase - ideas?
Both regtest on FC33/x86_64. The first was tested by Dominique (see the
PR). OK for master?
Typo – underscore-'c' should be a dot-'c' – both changelog files
* trans-expr_c (gfc_trans_scalar_assign): Make use of pre and
I think the second longer version is nicer in general, but at least for
GCC 9/GCC10 the first version is simpler and, hence, less error prone.
As you only ask about mainline, I would prefer the second one.
However, I am not happy about gfc_find_and_cut_at_last_class_ref:
+ of refs following. If ts is non-null the cut is at the class entity
+ or component that is followed by an array reference, which is not +
an element. */ ... + + if (ts) + { + if (e->symtree + &&
e->symtree->n.sym->ts.type == BT_CLASS) + *ts =
&e->symtree->n.sym->ts; + else + *ts = NULL; + } + for (ref = e->ref;
ref; ref = ref->next) { + if (ts && ref->type == REF_COMPONENT + &&
ref->u.c.component->ts.type == BT_CLASS + && ref->next &&
ref->next->type == REF_COMPONENT + && strcmp
(ref->next->u.c.component->name, "_data") == 0 + && ref->next->next +
&& ref->next->next->type == REF_ARRAY + && ref->next->next->u.ar.type
!= AR_ELEMENT) + { + *ts = &ref->u.c.component->ts; + class_ref = ref;
+ break; + } + + if (ts && *ts == NULL) + return NULL; +
Namely, if there is:
type1%array_class2 → array_class2 is used for 'ts' and later (ok)
type1%type%array_class2 → NULL is returned (why?)
class1%type%array_class2 → ts = class1 but array2_class is used later on
(ups!)
class1%...%scalar_class2 → ts = class1 but scalar_class2 is used
etc.
Thus this either needs to be cleaned up (separate 'ref' loop for
ts != NULL) – including the wording in the description which tells what
happens if 'ts' is passed as arg but the expr has rank == 0 – and
what value is assigned to 'ts'. (You can then also fix 'class.c::' to
'class.c: ' in the description above the function.)
Alternatively, you can leave the current code ref handling code in place
at build_class_array_ref, which might be the simpler alternative.
Otherwise, it looks sensible to me.
Tobias
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