Hi
This adds a diagnostic only,
tested on x86_64-linux,darwin powerpc64-linux,
applied to master as obvious,
thanks
Iain
---------
If the user provides operator new and that is noexcept, this
implies that it can fail with a null return. At that point, we expect
to be able to call get_return_object_on_allocation_failure().
This diagnoses the case where such an operator new has been
provided, but the g-r-o-o-a-f is either missing or unusable.
gcc/cp/ChangeLog:
* coroutines.cc (morph_fn_to_coro): Diagnose unavailable
get_return_object_on_allocation_failure.
gcc/testsuite/ChangeLog:
* g++.dg/coroutines/coro-bad-grooaf-01-grooaf-expected.C: New test.
---
gcc/cp/coroutines.cc | 4 ++++
.../coro-bad-grooaf-01-grooaf-expected.C | 14 ++++++++++++++
2 files changed, 18 insertions(+)
create mode 100644
gcc/testsuite/g++.dg/coroutines/coro-bad-grooaf-01-grooaf-expected.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 6e723c402db..8b8d00e8e0c 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -4041,6 +4041,10 @@ morph_fn_to_coro (tree orig, tree *resumer, tree
*destroyer)
else if (grooaf && !TYPE_NOTHROW_P (TREE_TYPE (func)))
error_at (fn_start, "%qE is provided by %qT but %qE is not marked"
" %<throw()%> or %<noexcept%>", grooaf, promise_type, nwname);
+ else if (!grooaf && TYPE_NOTHROW_P (TREE_TYPE (func)))
+ warning_at (fn_start, 0, "%qE is marked %<throw()%> or %<noexcept%> but"
+ " no usable %<get_return_object_on_allocation_failure%>"
+ " is provided by %qT ", nwname, promise_type);
}
else /* No operator new in the promise. */
{
diff --git
a/gcc/testsuite/g++.dg/coroutines/coro-bad-grooaf-01-grooaf-expected.C
b/gcc/testsuite/g++.dg/coroutines/coro-bad-grooaf-01-grooaf-expected.C
new file mode 100644
index 00000000000..9fa3d64a9f2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/coro-bad-grooaf-01-grooaf-expected.C
@@ -0,0 +1,14 @@
+/* g-r-o-o-a-f would be expected, since we have a noexcept op new. */
+
+#define USE_FAILING_OP_NEW
+#include "coro1-allocators.h"
+
+int used_grooaf = 0;
+
+struct coro1
+f () noexcept // { dg-warning {'operator new' is marked 'throw\(\)' or
'noexcept' but no usable 'get_return_object_on_allocation_failure' is provided
by 'std::__n4861::__coroutine_traits_impl<coro1, void>::promise_type' \{aka
'coro1::promise_type'\}} }
+{
+ PRINT ("coro1: about to return");
+ co_return;
+}
+
--
2.24.1
