On Fri, 6 May 2022, Jason Merrill wrote:
> On 5/6/22 16:10, Patrick Palka wrote:
> > On Fri, 6 May 2022, Patrick Palka wrote:
> >
> > > On Fri, 6 May 2022, Jason Merrill wrote:
> > >
> > > > On 5/6/22 14:00, Patrick Palka wrote:
> > > > > On Fri, 6 May 2022, Patrick Palka wrote:
> > > > >
> > > > > > On Fri, 6 May 2022, Jason Merrill wrote:
> > > > > >
> > > > > > > On 5/6/22 11:22, Patrick Palka wrote:
> > > > > > > > Here ever since r10-7313-gb599bf9d6d1e18,
> > > > > > > > reduced_constant_expression_p
> > > > > > > > in C++11/14 is rejecting the marked sub-aggregate initializer
> > > > > > > > (of type
> > > > > > > > S)
> > > > > > > >
> > > > > > > > W w = {.D.2445={.s={.D.2387={.m=0}, .b=0}}}
> > > > > > > > ^
> > > > > > > >
> > > > > > > > ultimately because said initializer has CONSTRUCTOR_NO_CLEARING
> > > > > > > > set,
> > > > > > > > and
> > > > > > > > so the function proceeds to verify that all fields of S are
> > > > > > > > initialized.
> > > > > > > > And before C++17 we don't expect to see base class fields (since
> > > > > > > > next_initializable_field skips over the), so the base class
> > > > > > > > initializer
> > > > > > > > causes r_c_e_p to return false.
> > > > > > >
> > > > > > > That seems like the primary bug. I guess r_c_e_p shouldn't be
> > > > > > > using
> > > > > > > next_initializable_field. Really that function should only be
> > > > > > > used for
> > > > > > > aggregates.
> > > > > >
> > > > > > I see, I'll try replacing it in r_c_e_p. Would that be in addition
> > > > > > to
> > > > > > or instead of the clear_no_implicit_zero approach?
> > > > >
> > > > > I'm testing the following, which uses a custom predicate instead of
> > > > > next_initializable_field in r_c_e_p.
> > > >
> > > > Let's make it a public predicate, not internal to r_c_e_p. Maybe it
> > > > could be
> > > > next_subobject_field, and the current next_initializable_field change to
> > > > next_aggregate_field?
> > >
> > > Will do.
> > >
> > > >
> > > > > Looks like the inner initializer {.D.2387={.m=0}, .b=0} is formed
> > > > > during
> > > > > the subobject constructor call:
> > > > >
> > > > > V::V (&((struct S *) this)->D.2120);
> > > > >
> > > > > after the evaluation of which, 'result' in cxx_eval_call_expression is
> > > > > NULL
> > > > > (presumably because it's a CALL_EXPR, not AGGR_INIT_EXPR?):
> > > > >
> > > > > /* This can be null for a subobject constructor call, in
> > > > > which case what we care about is the initialization
> > > > > side-effects rather than the value. We could get at the
> > > > > value by evaluating *this, but we don't bother; there's
> > > > > no need to put such a call in the hash table. */
> > > > > result = lval ? ctx->object : ctx->ctor;
> > > > >
> > > > > so we end up not calling clear_no_implicit_zero for the inner
> > > > > initializer
> > > > > directly. We only call clear_no_implicit_zero after evaluating the
> > > > > AGGR_INIT_EXPR for outermost initializer (of type W).
> > > >
> > > > Maybe for constructors we could call it on ctx->ctor instead of result,
> > > > or
> > > > call r_c_e_p in C++20+?
> > >
> > > But both ctx->ctor and ->object are NULL during a subobject constructor
> > > call (since we apparently clear these fields when entering a
> > > STATEMENT_LIST):
> > >
> > > So I tried instead obtaining the constructor by evaluating new_obj via
> > >
> > > --- a/gcc/cp/constexpr.cc
> > > +++ b/gcc/cp/constexpr.cc
> > > @@ -2993,6 +2988,9 @@ cxx_eval_call_expression (const constexpr_ctx *ctx,
> > > tree t,
> > > in order to detect reading an unitialized object in constexpr
> > > instead
> > > of value-initializing it. (reduced_constant_expression_p is
> > > expected to
> > > take care of clearing the flag.) */
> > > + if (new_obj && DECL_CONSTRUCTOR_P (fun))
> > > + result = cxx_eval_constant_expression (ctx, new_obj, /*lval=*/false,
> > > + non_constant_p, overflow_p);
> > > if (TREE_CODE (result) == CONSTRUCTOR
> > > && (cxx_dialect < cxx20
> > > || !DECL_CONSTRUCTOR_P (fun)))
> > >
> > > but that seems to break e.g. g++.dg/cpp2a/constexpr-init12.C because
> > > after the subobject constructor call
> > >
> > > S::S (&((struct W *) this)->s, NON_LVALUE_EXPR <8>);
> > >
> > > the constructor for the subobject a.s in new_obj is still completely
> > > missing (I suppose because S::S doesn't initialize any of its members)
> > > so trying to obtain it causes us to complain too soon from
> > > cxx_eval_component_reference:
> > >
> > > constexpr-init12.C:16:24: in ‘constexpr’ expansion of ‘W(42)’
> > > constexpr-init12.C:10:22: in ‘constexpr’ expansion of
> > > ‘((W*)this)->W::s.S::S(8)’
> > > constexpr-init12.C:16:24: error: accessing uninitialized member ‘W::s’
> > > 16 | constexpr auto a = W(42); // { dg-error "not a constant
> > > expression" }
> > > | ^
> > >
> > > >
> > > > It does seem dubious that we would clear the flag on an outer ctor when
> > > > it's
> > > > still set on an inner ctor, should probably add an assert somewhere.
> > >
> > > Makes sense, not sure where the best place would be..
> >
> > On second thought, if I'm understanding your suggestion correctly, I
> > don't think we can generally enforce such a property for
> > CONSTRUCTOR_NO_CLEARING, given how cxx_eval_store_expression uses it for
> > unions:
> >
> > union U {
> > struct { int x, y; } a;
> > } u;
> > u.a.x = 0;
> >
> > Here after evaluating the assignment, the outer ctor for the union will
> > have CONSTRUCTOR_NO_CLEARING cleared to indicate we finished activating
> > the union member, but the inner ctor is certainly not fully initialized
> > so it'll have CONSTRUCTOR_NO_CLEARING set still.
>
> Why clear the flag on the union before the inner ctor is fully initialized, if
> the intent is to prevent changing the active member during initialization?
>
> In the loop over ctors in cxx_eval_store_expression, I'd think if we encounter
> a CONSTRUCTOR_NO_CLEARING ctor along the way, we shouldn't clear the flag on
> an outer ctor.
Wouldn't that prevent us from later activating a different member, which is
allowed in C++20? It would cause us to reject e.g.
constexpr auto f() {
union U {
struct { int x, y; } a;
int b;
} u;
u.a.x = 0;
u.b = 0;
return u;
}
static_assert(f().b == 0);
even in C++20 with
<source>:7:7: error: change of the active member of a union from ‘f()::U::a’ to
‘f()::U::b’ during initialization
7 | u.b = 0;
| ~~~~^~~
because when evaluating the second assignment we'd see that the
CONSTRUCTOR_NO_CLEARING flag is still set on the union while it already
has an activated member.
On a related note, here's the patch that mechanically renames
next_initializable_field to next_aggregate_field and makes it skip over vptr
fields, and defines next_subobject_field alongside it for use by r_c_e_p.
Bootstrap and regtesting in progress.
-- >8 --
PR c++/105491
gcc/cp/ChangeLog:
* call.cc (field_in_pset): Adjust after next_initializable_field
renaming.
(build_aggr_conv): Likewise.
(convert_like_internal): Likewise.
(type_has_extended_temps): Likewise.
* class.cc (default_init_uninitialized_part): Likewise.
(finish_struct): Likewise.
* constexpr.cc (cx_check_missing_mem_inits): Likewise.
(reduced_constant_expression_p): Use next_subobject_field
instead.
* cp-gimplify.cc (get_source_location_impl_type): Adjust after
next_initializable_field renaming.
(fold_builtin_source_location): Likewise.
* cp-tree.h (next_initializable_field): Rename to ...
(next_aggregate_field): ... this.
(next_subobject_field): Declare.
* decl.cc (next_aggregate_field): Renamed from ...
(next_initializable_field): ... this. Skip over vptr fields.
Document that this is now intended for aggregate classes.
(next_subobject_field): Define.
(reshape_init_class): Adjust after next_initializable_field
renaming.
* init.cc (build_value_init_noctor): Likewise.
(emit_mem_initializers): Likewise.
* lambda.cc (build_capture_proxy): Likewise.
* method.cc (build_comparison_op): Likewise.
* pt.cc (maybe_aggr_guide): Likewise.
* tree.cc (structural_type_p): Likewise.
* typeck2.cc (split_nonconstant_init_1): Likewise.
(digest_init_r): Likewise.
gcc/testsuite/ChangeLog:
* gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C: New test.
* gcc/testsuite/g++.dg/cpp0x/constexpr-union7a.C: New test.
* gcc/testsuite/g++.dg/cpp2a/constinit17.C: New test.
---
gcc/cp/call.cc | 14 +++----
gcc/cp/class.cc | 8 ++--
gcc/cp/constexpr.cc | 10 ++---
gcc/cp/cp-gimplify.cc | 4 +-
gcc/cp/cp-tree.h | 3 +-
gcc/cp/decl.cc | 38 +++++++++++++------
gcc/cp/init.cc | 6 +--
gcc/cp/lambda.cc | 4 +-
gcc/cp/method.cc | 8 ++--
gcc/cp/pt.cc | 2 +-
gcc/cp/tree.cc | 4 +-
gcc/cp/typeck2.cc | 4 +-
gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C | 17 +++++++++
.../g++.dg/cpp0x/constexpr-union7a.C | 15 ++++++++
gcc/testsuite/g++.dg/cpp2a/constinit17.C | 24 ++++++++++++
15 files changed, 117 insertions(+), 44 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C
create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-union7a.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/constinit17.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 959279d6216..0240e364324 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -948,7 +948,7 @@ field_in_pset (hash_set<tree, true> &pset, tree field)
for (field = TYPE_FIELDS (TREE_TYPE (field));
field; field = DECL_CHAIN (field))
{
- field = next_initializable_field (field);
+ field = next_aggregate_field (field);
if (field == NULL_TREE)
break;
if (field_in_pset (pset, field))
@@ -965,7 +965,7 @@ build_aggr_conv (tree type, tree ctor, int flags,
tsubst_flags_t complain)
{
unsigned HOST_WIDE_INT i = 0;
conversion *c;
- tree field = next_initializable_field (TYPE_FIELDS (type));
+ tree field = next_aggregate_field (TYPE_FIELDS (type));
tree empty_ctor = NULL_TREE;
hash_set<tree, true> pset;
@@ -1011,7 +1011,7 @@ build_aggr_conv (tree type, tree ctor, int flags,
tsubst_flags_t complain)
}
}
- for (; field; field = next_initializable_field (DECL_CHAIN (field)))
+ for (; field; field = next_aggregate_field (DECL_CHAIN (field)))
{
tree ftype = TREE_TYPE (field);
tree val;
@@ -8098,10 +8098,10 @@ convert_like_internal (conversion *convs, tree expr,
tree fn, int argnum,
totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain);
if (!totype)
return error_mark_node;
- tree field = next_initializable_field (TYPE_FIELDS (totype));
+ tree field = next_aggregate_field (TYPE_FIELDS (totype));
vec<constructor_elt, va_gc> *vec = NULL;
CONSTRUCTOR_APPEND_ELT (vec, field, array);
- field = next_initializable_field (DECL_CHAIN (field));
+ field = next_aggregate_field (DECL_CHAIN (field));
CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
tree new_ctor = build_constructor (totype, vec);
return get_target_expr_sfinae (new_ctor, complain);
@@ -13267,8 +13267,8 @@ type_has_extended_temps (tree type)
{
if (is_std_init_list (type))
return true;
- for (tree f = next_initializable_field (TYPE_FIELDS (type));
- f; f = next_initializable_field (DECL_CHAIN (f)))
+ for (tree f = next_aggregate_field (TYPE_FIELDS (type));
+ f; f = next_aggregate_field (DECL_CHAIN (f)))
if (type_has_extended_temps (TREE_TYPE (f)))
return true;
}
diff --git a/gcc/cp/class.cc b/gcc/cp/class.cc
index bc94ed45e17..3c195b35396 100644
--- a/gcc/cp/class.cc
+++ b/gcc/cp/class.cc
@@ -5494,8 +5494,8 @@ default_init_uninitialized_part (tree type)
if (r)
return r;
}
- for (t = next_initializable_field (TYPE_FIELDS (type)); t;
- t = next_initializable_field (DECL_CHAIN (t)))
+ for (t = next_aggregate_field (TYPE_FIELDS (type)); t;
+ t = next_aggregate_field (DECL_CHAIN (t)))
if (!DECL_INITIAL (t) && !DECL_ARTIFICIAL (t))
{
r = default_init_uninitialized_part (TREE_TYPE (t));
@@ -7781,10 +7781,10 @@ finish_struct (tree t, tree attributes)
bool ok = false;
if (processing_template_decl)
{
- tree f = next_initializable_field (TYPE_FIELDS (t));
+ tree f = next_aggregate_field (TYPE_FIELDS (t));
if (f && TYPE_PTR_P (TREE_TYPE (f)))
{
- f = next_initializable_field (DECL_CHAIN (f));
+ f = next_aggregate_field (DECL_CHAIN (f));
if (f && same_type_p (TREE_TYPE (f), size_type_node))
ok = true;
}
diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index 9b1e71857fc..24717b4f8d5 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -784,7 +784,7 @@ cx_check_missing_mem_inits (tree ctype, tree body, bool
complain)
if (TREE_CODE (ctype) == UNION_TYPE)
{
- if (nelts == 0 && next_initializable_field (field))
+ if (nelts == 0 && next_aggregate_field (field))
{
if (complain)
error ("%<constexpr%> constructor for union %qT must "
@@ -3053,7 +3053,7 @@ reduced_constant_expression_p (tree t)
field = NULL_TREE;
}
else
- field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t)));
+ field = next_subobject_field (TYPE_FIELDS (TREE_TYPE (t)));
}
else
field = NULL_TREE;
@@ -3065,15 +3065,15 @@ reduced_constant_expression_p (tree t)
return false;
/* Empty class field may or may not have an initializer. */
for (; field && e.index != field;
- field = next_initializable_field (DECL_CHAIN (field)))
+ field = next_subobject_field (DECL_CHAIN (field)))
if (!is_really_empty_class (TREE_TYPE (field),
/*ignore_vptr*/false))
return false;
if (field)
- field = next_initializable_field (DECL_CHAIN (field));
+ field = next_subobject_field (DECL_CHAIN (field));
}
/* There could be a non-empty field at the end. */
- for (; field; field = next_initializable_field (DECL_CHAIN (field)))
+ for (; field; field = next_subobject_field (DECL_CHAIN (field)))
if (!is_really_empty_class (TREE_TYPE (field), /*ignore_vptr*/false))
return false;
ok:
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc
index b52d9cb5754..ee47a4bfd37 100644
--- a/gcc/cp/cp-gimplify.cc
+++ b/gcc/cp/cp-gimplify.cc
@@ -3106,7 +3106,7 @@ get_source_location_impl_type (location_t loc)
int cnt = 0;
for (tree field = TYPE_FIELDS (type);
- (field = next_initializable_field (field)) != NULL_TREE;
+ (field = next_aggregate_field (field)) != NULL_TREE;
field = DECL_CHAIN (field))
{
if (DECL_NAME (field) != NULL_TREE)
@@ -3281,7 +3281,7 @@ fold_builtin_source_location (location_t loc)
vec<constructor_elt, va_gc> *v = NULL;
vec_alloc (v, 4);
for (tree field = TYPE_FIELDS (source_location_impl);
- (field = next_initializable_field (field)) != NULL_TREE;
+ (field = next_aggregate_field (field)) != NULL_TREE;
field = DECL_CHAIN (field))
{
const char *n = IDENTIFIER_POINTER (DECL_NAME (field));
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 663fe7a20fc..abcef7c20c4 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6870,7 +6870,8 @@ extern bool is_direct_enum_init (tree,
tree);
extern void initialize_artificial_var (tree, vec<constructor_elt,
va_gc> *);
extern tree check_var_type (tree, tree, location_t);
extern tree reshape_init (tree, tree, tsubst_flags_t);
-extern tree next_initializable_field (tree);
+extern tree next_aggregate_field (tree);
+extern tree next_subobject_field (tree);
extern tree first_field (const_tree);
extern tree fndecl_declared_return_type (tree);
extern bool undeduced_auto_decl (tree);
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index c9110db796a..d5ab2d0ad87 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -6382,22 +6382,38 @@ struct reshape_iter
static tree reshape_init_r (tree, reshape_iter *, tree, tsubst_flags_t);
+/* FIELD is an element of TYPE_FIELDS of an aggregate class, or NULL. In the
+ former case, the value returned is the next FIELD_DECL (possibly FIELD
+ itself) that can be initialized. If there are no more such fields, the
+ return value will be NULL. */
+
+tree
+next_aggregate_field (tree field)
+{
+ while (field
+ && (TREE_CODE (field) != FIELD_DECL
+ || DECL_UNNAMED_BIT_FIELD (field)
+ || (DECL_ARTIFICIAL (field)
+ /* In C++17, aggregates can have base classes. */
+ && !(cxx_dialect >= cxx17 && DECL_FIELD_IS_BASE (field)))))
+ field = DECL_CHAIN (field);
+
+ return field;
+}
+
/* FIELD is an element of TYPE_FIELDS or NULL. In the former case, the value
- returned is the next FIELD_DECL (possibly FIELD itself) that can be
- initialized. If there are no more such fields, the return value
- will be NULL. */
+ returned is the next FIELD_DECL (possibly FIELD itself) that corresponds
+ to a subobject. If there are no more such fields, the return value will be
+ NULL. */
tree
-next_initializable_field (tree field)
+next_subobject_field (tree field)
{
while (field
&& (TREE_CODE (field) != FIELD_DECL
|| DECL_UNNAMED_BIT_FIELD (field)
|| (DECL_ARTIFICIAL (field)
- /* In C++17, don't skip base class fields. */
- && !(cxx_dialect >= cxx17 && DECL_FIELD_IS_BASE (field))
- /* Don't skip vptr fields. We might see them when we're
- called from reduced_constant_expression_p. */
+ && !DECL_FIELD_IS_BASE (field)
&& !DECL_VIRTUAL_P (field))))
field = DECL_CHAIN (field);
@@ -6595,7 +6611,7 @@ reshape_init_class (tree type, reshape_iter *d, bool
first_initializer_p,
if (base_binfo)
field = base_binfo;
else
- field = next_initializable_field (TYPE_FIELDS (type));
+ field = next_aggregate_field (TYPE_FIELDS (type));
if (!field)
{
@@ -6760,10 +6776,10 @@ reshape_init_class (tree type, reshape_iter *d, bool
first_initializer_p,
if (BINFO_BASE_ITERATE (binfo, ++binfo_idx, base_binfo))
field = base_binfo;
else
- field = next_initializable_field (TYPE_FIELDS (type));
+ field = next_aggregate_field (TYPE_FIELDS (type));
}
else
- field = next_initializable_field (DECL_CHAIN (field));
+ field = next_aggregate_field (DECL_CHAIN (field));
}
/* A trailing aggregate element that is a pack expansion is assumed to
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc
index 75ab965a218..f1ed9336dc9 100644
--- a/gcc/cp/init.cc
+++ b/gcc/cp/init.cc
@@ -422,7 +422,7 @@ build_value_init_noctor (tree type, tsubst_flags_t complain)
&& !COMPLETE_TYPE_P (ftype)
&& !TYPE_DOMAIN (ftype)
&& COMPLETE_TYPE_P (TREE_TYPE (ftype))
- && (next_initializable_field (DECL_CHAIN (field))
+ && (next_aggregate_field (DECL_CHAIN (field))
== NULL_TREE))
continue;
@@ -1477,9 +1477,9 @@ emit_mem_initializers (tree mem_inits)
/* Initially that is all of them. */
if (warn_uninitialized)
- for (tree f = next_initializable_field (TYPE_FIELDS (current_class_type));
+ for (tree f = next_aggregate_field (TYPE_FIELDS (current_class_type));
f != NULL_TREE;
- f = next_initializable_field (DECL_CHAIN (f)))
+ f = next_aggregate_field (DECL_CHAIN (f)))
if (!DECL_ARTIFICIAL (f)
&& !is_really_empty_class (TREE_TYPE (f), /*ignore_vptr*/false))
uninitialized.add (f);
diff --git a/gcc/cp/lambda.cc b/gcc/cp/lambda.cc
index afac53b6d7c..27704a578af 100644
--- a/gcc/cp/lambda.cc
+++ b/gcc/cp/lambda.cc
@@ -425,9 +425,9 @@ build_capture_proxy (tree member, tree init)
if (DECL_VLA_CAPTURE_P (member))
{
/* Rebuild the VLA type from the pointer and maxindex. */
- tree field = next_initializable_field (TYPE_FIELDS (type));
+ tree field = next_aggregate_field (TYPE_FIELDS (type));
tree ptr = build_simple_component_ref (object, field);
- field = next_initializable_field (DECL_CHAIN (field));
+ field = next_aggregate_field (DECL_CHAIN (field));
tree max = build_simple_component_ref (object, field);
type = build_cplus_array_type (TREE_TYPE (TREE_TYPE (ptr)),
build_index_type (max));
diff --git a/gcc/cp/method.cc b/gcc/cp/method.cc
index 903ee666ef3..0dffd648b0b 100644
--- a/gcc/cp/method.cc
+++ b/gcc/cp/method.cc
@@ -1465,7 +1465,7 @@ build_comparison_op (tree fndecl, bool defining,
tsubst_flags_t complain)
/* A defaulted comparison operator function for class C is defined as
deleted if ... C has variant members. */
if (TREE_CODE (ctype) == UNION_TYPE
- && next_initializable_field (TYPE_FIELDS (ctype)))
+ && next_aggregate_field (TYPE_FIELDS (ctype)))
{
if (complain & tf_error)
inform (info.loc, "cannot default compare union %qT", ctype);
@@ -1518,9 +1518,9 @@ build_comparison_op (tree fndecl, bool defining,
tsubst_flags_t complain)
}
/* Now compare the field subobjects. */
- for (tree field = next_initializable_field (TYPE_FIELDS (ctype));
+ for (tree field = next_aggregate_field (TYPE_FIELDS (ctype));
field;
- field = next_initializable_field (DECL_CHAIN (field)))
+ field = next_aggregate_field (DECL_CHAIN (field)))
{
if (DECL_VIRTUAL_P (field) || DECL_FIELD_IS_BASE (field))
/* We ignore the vptr, and we already handled bases. */
@@ -1542,7 +1542,7 @@ build_comparison_op (tree fndecl, bool defining,
tsubst_flags_t complain)
continue;
}
else if (ANON_UNION_TYPE_P (expr_type)
- && next_initializable_field (TYPE_FIELDS (expr_type)))
+ && next_aggregate_field (TYPE_FIELDS (expr_type)))
{
if (complain & tf_error)
inform (field_loc, "cannot default compare "
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index ac002907a41..86e7212daa5 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -29578,7 +29578,7 @@ maybe_aggr_guide (tree tmpl, tree init, vec<tree,va_gc>
*args)
len;
--len, field = DECL_CHAIN (field))
{
- field = next_initializable_field (field);
+ field = next_aggregate_field (field);
if (!field)
return NULL_TREE;
tree ftype = finish_decltype_type (field, true, complain);
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc
index ed0d0d22950..aba695116c5 100644
--- a/gcc/cp/tree.cc
+++ b/gcc/cp/tree.cc
@@ -4852,8 +4852,8 @@ structural_type_p (tree t, bool explain)
explain_non_literal_class (t);
return false;
}
- for (tree m = next_initializable_field (TYPE_FIELDS (t)); m;
- m = next_initializable_field (DECL_CHAIN (m)))
+ for (tree m = next_aggregate_field (TYPE_FIELDS (t)); m;
+ m = next_aggregate_field (DECL_CHAIN (m)))
{
if (TREE_PRIVATE (m) || TREE_PROTECTED (m))
{
diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc
index 63d95c1529a..1d92310edd0 100644
--- a/gcc/cp/typeck2.cc
+++ b/gcc/cp/typeck2.cc
@@ -606,7 +606,7 @@ split_nonconstant_init_1 (tree dest, tree init, bool last,
: TYPE_FIELDS (type));
; prev = DECL_CHAIN (prev))
{
- prev = next_initializable_field (prev);
+ prev = next_aggregate_field (prev);
if (prev == field_index)
break;
tree ptype = TREE_TYPE (prev);
@@ -1304,7 +1304,7 @@ digest_init_r (tree type, tree init, int nested, int
flags,
the first element of d, which is the B base subobject. The base
of type B is copy-initialized from the D temporary, causing
object slicing. */
- tree field = next_initializable_field (TYPE_FIELDS (type));
+ tree field = next_aggregate_field (TYPE_FIELDS (type));
if (field && DECL_FIELD_IS_BASE (field))
{
if (warning_at (loc, 0, "initializing a base class of type %qT "
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C
new file mode 100644
index 00000000000..b3147d9db50
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-union7.C
@@ -0,0 +1,17 @@
+// PR c++/105491
+// { dg-do compile { target c++11 } }
+
+struct V {
+ int m = 0;
+};
+struct S : V {
+ constexpr S(int) : b() { }
+ bool b;
+};
+struct W {
+ constexpr W() : s(0) { }
+ union {
+ S s;
+ };
+};
+constexpr W w;
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-union7a.C
b/gcc/testsuite/g++.dg/cpp0x/constexpr-union7a.C
new file mode 100644
index 00000000000..b676e7d1748
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-union7a.C
@@ -0,0 +1,15 @@
+// PR c++/105491
+// { dg-do compile { target c++11 } }
+
+struct V {
+ int m = 0;
+};
+struct S : V {
+ constexpr S(int) : b() { }
+ bool b;
+};
+union W {
+ constexpr W() : s(0) { }
+ S s;
+};
+constexpr W w;
diff --git a/gcc/testsuite/g++.dg/cpp2a/constinit17.C
b/gcc/testsuite/g++.dg/cpp2a/constinit17.C
new file mode 100644
index 00000000000..6431654ac85
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/constinit17.C
@@ -0,0 +1,24 @@
+// PR c++/105491
+// { dg-do compile { target c++11 } }
+
+class Message {
+ virtual int GetMetadata();
+};
+class ProtobufCFileOptions : Message {
+public:
+ constexpr ProtobufCFileOptions(int);
+ bool no_generate_;
+ bool const_strings_;
+ bool use_oneof_field_name_;
+ bool gen_pack_helpers_;
+ bool gen_init_helpers_;
+};
+constexpr ProtobufCFileOptions::ProtobufCFileOptions(int)
+ : no_generate_(), const_strings_(), use_oneof_field_name_(),
+ gen_pack_helpers_(), gen_init_helpers_() {}
+struct ProtobufCFileOptionsDefaultTypeInternal {
+ constexpr ProtobufCFileOptionsDefaultTypeInternal() : _instance({}) {}
+ union {
+ ProtobufCFileOptions _instance;
+ };
+} __constinit _ProtobufCFileOptions_default_instance_;
--
2.36.0.63.gf5aaf72f1b
