[C++ PATCH] Further fix for designated-initializer-list handling in overload resolution (PR c++/71446)
Jakub Jelinek
jakub@redhat.com
Mon Mar 4 09:21:00 GMT 2019
On Sat, Mar 02, 2019 at 10:30:36AM +0100, Jakub Jelinek wrote:
> I'm not really sure what to do for foo. Perhaps if we find that case just
> require that the order is ok already during build_aggr_conv and fail the
> conversion otherwise? We are outside of the standard in that case anyway.
Actually, seems if the designators can match corresponding type,
reshape_init* already fills in the ce->index even on elements without
original designators. So, the following works fine for all the testcases I
came up with.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-03-04 Jakub Jelinek <jakub@redhat.com>
PR c++/71446
* call.c (field_in_pset): New function.
(build_aggr_conv): Handle CONSTRUCTOR_IS_DESIGNATED_INIT correctly.
* g++.dg/cpp2a/desig12.C: New test.
* g++.dg/cpp2a/desig13.C: New test.
--- gcc/cp/call.c.jj 2019-03-02 09:05:44.442524338 +0100
+++ gcc/cp/call.c 2019-03-02 18:57:12.221904541 +0100
@@ -902,6 +902,28 @@ can_convert_array (tree atype, tree ctor
return true;
}
+/* Helper for build_aggr_conv. Return true if FIELD is in PSET, or if
+ FIELD has ANON_AGGR_TYPE_P and any initializable field in there recursively
+ is in PSET. */
+
+static bool
+field_in_pset (hash_set<tree> *pset, tree field)
+{
+ if (pset->contains (field))
+ return true;
+ if (ANON_AGGR_TYPE_P (TREE_TYPE (field)))
+ for (field = TYPE_FIELDS (TREE_TYPE (field));
+ field; field = DECL_CHAIN (field))
+ {
+ field = next_initializable_field (field);
+ if (field == NULL_TREE)
+ break;
+ if (field_in_pset (pset, field))
+ return true;
+ }
+ return false;
+}
+
/* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
aggregate class, if such a conversion is possible. */
@@ -912,6 +934,7 @@ build_aggr_conv (tree type, tree ctor, i
conversion *c;
tree field = next_initializable_field (TYPE_FIELDS (type));
tree empty_ctor = NULL_TREE;
+ hash_set<tree> *pset = NULL;
/* We already called reshape_init in implicit_conversion. */
@@ -919,26 +942,69 @@ build_aggr_conv (tree type, tree ctor, i
context; they're always simple copy-initialization. */
flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
+ /* For designated initializers, verify that each initializer is convertible
+ to corresponding TREE_TYPE (ce->index) and mark those FIELD_DECLs as
+ visited. In the following loop then ignore already visited
+ FIELD_DECLs. */
+ if (CONSTRUCTOR_IS_DESIGNATED_INIT (ctor))
+ {
+ tree idx, val;
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, val)
+ {
+ if (idx && TREE_CODE (idx) == FIELD_DECL)
+ {
+ tree ftype = TREE_TYPE (idx);
+ bool ok;
+
+ if (TREE_CODE (ftype) == ARRAY_TYPE
+ && TREE_CODE (val) == CONSTRUCTOR)
+ ok = can_convert_array (ftype, val, flags, complain);
+ else
+ ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags,
+ complain);
+
+ if (!ok)
+ goto fail;
+ /* For unions, there should be just one initializer. */
+ if (TREE_CODE (type) == UNION_TYPE)
+ {
+ field = NULL_TREE;
+ i = 1;
+ break;
+ }
+ if (pset == NULL)
+ pset = new hash_set<tree>;
+ pset->add (idx);
+ }
+ else
+ goto fail;
+ }
+ }
+
for (; field; field = next_initializable_field (DECL_CHAIN (field)))
{
tree ftype = TREE_TYPE (field);
tree val;
bool ok;
+ if (pset && field_in_pset (pset, field))
+ continue;
if (i < CONSTRUCTOR_NELTS (ctor))
- val = CONSTRUCTOR_ELT (ctor, i)->value;
+ {
+ val = CONSTRUCTOR_ELT (ctor, i)->value;
+ ++i;
+ }
else if (DECL_INITIAL (field))
val = get_nsdmi (field, /*ctor*/false, complain);
else if (TYPE_REF_P (ftype))
/* Value-initialization of reference is ill-formed. */
- return NULL;
+ goto fail;
else
{
if (empty_ctor == NULL_TREE)
empty_ctor = build_constructor (init_list_type_node, NULL);
val = empty_ctor;
}
- ++i;
if (TREE_CODE (ftype) == ARRAY_TYPE
&& TREE_CODE (val) == CONSTRUCTOR)
@@ -948,15 +1014,22 @@ build_aggr_conv (tree type, tree ctor, i
complain);
if (!ok)
- return NULL;
+ goto fail;
if (TREE_CODE (type) == UNION_TYPE)
break;
}
if (i < CONSTRUCTOR_NELTS (ctor))
- return NULL;
+ {
+ fail:
+ if (pset)
+ delete pset;
+ return NULL;
+ }
+ if (pset)
+ delete pset;
c = alloc_conversion (ck_aggr);
c->type = type;
c->rank = cr_exact;
--- gcc/testsuite/g++.dg/cpp2a/desig12.C.jj 2019-03-02 18:58:26.300704919 +0100
+++ gcc/testsuite/g++.dg/cpp2a/desig12.C 2019-03-02 18:59:29.033689025 +0100
@@ -0,0 +1,15 @@
+// PR c++/71446
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+struct T { void *a; int b; };
+struct U { int a; union { int b; union { long c; short d; }; }; int e; };
+void bar (T);
+void baz (U);
+
+void
+foo ()
+{
+ bar ({.b = 1});
+ baz ({.c = 5L, .e = 6});
+}
--- gcc/testsuite/g++.dg/cpp2a/desig13.C.jj 2019-03-02 19:00:33.812639999 +0100
+++ gcc/testsuite/g++.dg/cpp2a/desig13.C 2019-03-02 19:03:48.043494642 +0100
@@ -0,0 +1,16 @@
+// PR c++/71446
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+struct S { int a, b, c, d, e; };
+struct T { int a, b; };
+void foo (S);
+void bar (T);
+
+void
+baz ()
+{
+ foo ({.d = 5, 6, .b = 2, 3}); // { dg-error "designator order for field 'S::b' does not match declaration order in 'S'" }
+ // { dg-error "either all initializer clauses should be designated or none of them should be" "" { target c++2a } .-1 }
+ bar ({.b = 1, .a = 2}); // { dg-error "designator order for field 'T::a' does not match declaration order in 'T'" }
+}
Jakub
More information about the Gcc-patches
mailing list