thanks
Iain
gcc/cp/ChangeLog:
PR c++/95345
* coroutines.cc (finish_co_await_expr): Revise to allow for
parameter packs.
(finish_co_yield_expr): Likewise.
gcc/testsuite/ChangeLog:
PR c++/95345
* g++.dg/coroutines/pr95345.C: New test.
---
gcc/cp/coroutines.cc | 45 +++++++++++------------
gcc/testsuite/g++.dg/coroutines/pr95345.C | 32 ++++++++++++++++
2 files changed, 53 insertions(+), 24 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/coroutines/pr95345.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index cc685ca73b2..7afa550037c 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -851,19 +851,18 @@ finish_co_await_expr (location_t kw, tree expr)
/* The current function has now become a coroutine, if it wasn't already.
*/
DECL_COROUTINE_P (current_function_decl) = 1;
- if (processing_template_decl)
- {
- current_function_returns_value = 1;
-
- if (check_for_bare_parameter_packs (expr))
- return error_mark_node;
+ /* This function will appear to have no return statement, even if it
+ is declared to return non-void (most likely). This is correct - we
+ synthesize the return for the ramp in the compiler. So suppress any
+ extraneous warnings during substitution. */
+ TREE_NO_WARNING (current_function_decl) = true;
- /* If we don't know the promise type, we can't proceed. */
- tree functype = TREE_TYPE (current_function_decl);
- if (dependent_type_p (functype) || type_dependent_expression_p (expr))
- return build5_loc (kw, CO_AWAIT_EXPR, unknown_type_node, expr,
- NULL_TREE, NULL_TREE, NULL_TREE, integer_zero_node);
- }
+ /* If we don't know the promise type, we can't proceed, build the
+ co_await with the expression unchanged. */
+ tree functype = TREE_TYPE (current_function_decl);
+ if (dependent_type_p (functype) || type_dependent_expression_p (expr))
+ return build5_loc (kw, CO_AWAIT_EXPR, unknown_type_node, expr,
+ NULL_TREE, NULL_TREE, NULL_TREE, integer_zero_node);
/* We must be able to look up the "await_transform" method in the scope of
the promise type, and obtain its return type. */
@@ -928,19 +927,17 @@ finish_co_yield_expr (location_t kw, tree expr)
/* The current function has now become a coroutine, if it wasn't already.
*/
DECL_COROUTINE_P (current_function_decl) = 1;
- if (processing_template_decl)
- {
- current_function_returns_value = 1;
-
- if (check_for_bare_parameter_packs (expr))
- return error_mark_node;
+ /* This function will appear to have no return statement, even if it
+ is declared to return non-void (most likely). This is correct - we
+ synthesize the return for the ramp in the compiler. So suppress any
+ extraneous warnings during substitution. */
+ TREE_NO_WARNING (current_function_decl) = true;
- tree functype = TREE_TYPE (current_function_decl);
- /* If we don't know the promise type, we can't proceed. */
- if (dependent_type_p (functype) || type_dependent_expression_p (expr))
- return build2_loc (kw, CO_YIELD_EXPR, unknown_type_node, expr,
- NULL_TREE);
- }
+ /* If we don't know the promise type, we can't proceed, build the
+ co_await with the expression unchanged. */
+ tree functype = TREE_TYPE (current_function_decl);
+ if (dependent_type_p (functype) || type_dependent_expression_p (expr))
+ return build2_loc (kw, CO_YIELD_EXPR, unknown_type_node, expr, NULL_TREE);
if (!coro_promise_type_found_p (current_function_decl, kw))
/* We must be able to look up the "yield_value" method in the scope of
diff --git a/gcc/testsuite/g++.dg/coroutines/pr95345.C
b/gcc/testsuite/g++.dg/coroutines/pr95345.C
new file mode 100644
index 00000000000..90e946d91c2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr95345.C
@@ -0,0 +1,32 @@
+#if __has_include (<coroutine>)
+#include <coroutine>
+using namespace std;
+#elif defined (__clang__) && __has_include (<experimental/coroutine>)
+#include <experimental/coroutine>
+using namespace std::experimental;
+#endif
+
+struct dummy_coro
+{
+ using promise_type = dummy_coro;
+ bool await_ready() { return false; }
+ void await_suspend(std::coroutine_handle<>) { }
+ void await_resume() { }
+ dummy_coro get_return_object() { return {}; }
+ dummy_coro initial_suspend() { return {}; }
+ dummy_coro final_suspend() { return {}; }
+ void return_void() { }
+ void unhandled_exception() { }
+};
+
+template <int ...I>
+dummy_coro
+foo()
+{
+ ((co_await [](int){ return std::suspend_never{}; }(I)), ...);
+ co_return;
+}
+
+void bar() {
+ foo<1>();
+}
