On 5/16/23 11:38, Patrick Palka wrote:
add_list_candidates has logic to reject designated initialization of a
non-aggregate type, but this is inadvertendly being suppressed if the type
has a list constructor due to the order of case analysis, which in the
below testcase leads to us incorrectly treating the list initializer as
an ordinary non-designated one. This patch fixes this by making us check
for invalid designated initialization sooner.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for
trunk and perhaps 13? IIUC desig init is C++20 but we also accept it
with a pedwarn in earlier dialects, so not sure if this'd be suitable
for backporting.
OK.
PR c++/109871
gcc/cp/ChangeLog:
* call.cc (add_list_candidates): Check for invalid
designated initialization sooner, even for types that have
a list constructor.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/desig6.C: New test.
---
gcc/cp/call.cc | 16 ++++++++--------
gcc/testsuite/g++.dg/cpp0x/desig6.C | 16 ++++++++++++++++
2 files changed, 24 insertions(+), 8 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/desig6.C
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc
index 48611bb16a3..908374a43c9 100644
--- a/gcc/cp/call.cc
+++ b/gcc/cp/call.cc
@@ -4129,6 +4129,14 @@ add_list_candidates (tree fns, tree first_arg,
if (CONSTRUCTOR_NELTS (init_list) == 0
&& TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
;
+ else if (CONSTRUCTOR_IS_DESIGNATED_INIT (init_list)
+ && !CP_AGGREGATE_TYPE_P (totype))
+ {
+ if (complain & tf_error)
+ error ("designated initializers cannot be used with a "
+ "non-aggregate type %qT", totype);
+ return;
+ }
/* If the class has a list ctor, try passing the list as a single
argument first, but only consider list ctors. */
else if (TYPE_HAS_LIST_CTOR (totype))
@@ -4140,14 +4148,6 @@ add_list_candidates (tree fns, tree first_arg,
if (any_strictly_viable (*candidates))
return;
}
- else if (CONSTRUCTOR_IS_DESIGNATED_INIT (init_list)
- && !CP_AGGREGATE_TYPE_P (totype))
- {
- if (complain & tf_error)
- error ("designated initializers cannot be used with a "
- "non-aggregate type %qT", totype);
- return;
- }
/* Expand the CONSTRUCTOR into a new argument vec. */
vec<tree, va_gc> *new_args;
diff --git a/gcc/testsuite/g++.dg/cpp0x/desig6.C
b/gcc/testsuite/g++.dg/cpp0x/desig6.C
new file mode 100644
index 00000000000..8d4cf483176
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/desig6.C
@@ -0,0 +1,16 @@
+// PR c++/109871
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+#include <initializer_list>
+
+struct vector {
+ vector(std::initializer_list<int>); // #1
+ vector(int); // #2
+};
+
+void f(vector);
+
+int main() {
+ f({.blah = 42}); // { dg-error "designated" } previously incorrectly
selected #2
+}
