In this PR we're emitting -Wnoexcept warnings about potentially-throwing NSDMIs
when computing the noexcept specification of a class's defaulted default
constructor. Alhough these warnings are in some sense valid, this patch takes
the route of suppressing them, because:
1. the warning message is confusing in its current form;
2. warning for 'struct C { B b = B(); };' but not for 'struct C { B b; };'
is inconsistent; and
3. emitting a warning here arguably doesn't fall under the umbrella of
-Wnoexcept, whose documentation says it warns only when a
noexcept-expression evaluates to false, but there are noexcept-expressions
here.
Tested on x86_64-pc-linux-gnu, does this look OK to commit?
gcc/cp/ChangeLog:
PR c++/93805
* method.c (walk_field_subobs): Pass tf_none as the complain argument to
expr_noexcept_p.
gcc/testsuite/ChangeLog:
PR c++/93805
* g++.dg/warn/Wnoexcept2.C: New test.
---
gcc/cp/method.c | 2 +-
gcc/testsuite/g++.dg/warn/Wnoexcept2.C | 15 +++++++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/warn/Wnoexcept2.C
diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index c131fd41536..41b9ff86bdd 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -1988,7 +1988,7 @@ walk_field_subobs (tree fields, special_function_kind
sfk, tree fnname,
if (nsdmi == error_mark_node)
*spec_p = error_mark_node;
else if (*spec_p != error_mark_node
- && !expr_noexcept_p (nsdmi, complain))
+ && !expr_noexcept_p (nsdmi, tf_none))
*spec_p = noexcept_false_spec;
}
/* Don't do the normal processing. */
diff --git a/gcc/testsuite/g++.dg/warn/Wnoexcept2.C
b/gcc/testsuite/g++.dg/warn/Wnoexcept2.C
new file mode 100644
index 00000000000..60541be3575
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wnoexcept2.C
@@ -0,0 +1,15 @@
+// PR c++/93805
+// { dg-do compile { target c++11 } }
+// { dg-additional-options "-Wnoexcept" }
+
+struct B
+{
+ B() {}
+};
+
+struct C
+{
+ B b = B();
+};
+
+C c; // { dg-bogus "noexcept-expression" }
--
2.26.0.rc1.11.g30e9940356
