gcc/cp/ChangeLog:
* coroutines.cc
(cp_coroutine_transform::build_ramp_function): Use
decltype(auto) to determine the type of the temporary
get_return_object.
gcc/testsuite/ChangeLog:
* g++.dg/coroutines/pr115908.C: Count promise construction
and destruction.
Signed-off-by: Iain Sandoe <i...@sandoe.co.uk>
---
gcc/cp/coroutines.cc | 22 ++++---
gcc/testsuite/g++.dg/coroutines/pr115908.C | 74 +++++++++++++++-------
2 files changed, 65 insertions(+), 31 deletions(-)
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 6169a81cea5..bd51c31e615 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -5120,8 +5120,11 @@ cp_coroutine_transform::build_ramp_function ()
/* Check for a bad get return object type.
[dcl.fct.def.coroutine] / 7 requires:
The expression promise.get_return_object() is used to
initialize the
- returned reference or prvalue result object ... */
- tree gro_type = TREE_TYPE (get_ro);
+ returned reference or prvalue result object ...
+ When we use a local to hold this, it is decltype(auto). */
+ tree gro_type
+ = finish_decltype_type (get_ro, /
*id_expression_or_member_access_p*/false,
+ tf_warning_or_error); // TREE_TYPE (get_ro);
if (VOID_TYPE_P (gro_type) && !void_ramp_p)
{
error_at (fn_start, "no viable conversion from %<void%>
provided by"
@@ -5129,11 +5132,6 @@ cp_coroutine_transform::build_ramp_function ()
return false;
}
- /* Initialize the resume_idx_var to 0, meaning "not started". */
- coro_build_and_push_artificial_var_with_dve
- (loc, coro_resume_index_id, short_unsigned_type_node, orig_fn_decl,
- build_zero_cst (short_unsigned_type_node), deref_fp);
-
/* We must manage the cleanups ourselves, with the exception of
the g_r_o,
because the responsibility for them changes after the initial
suspend.
However, any use of cxx_maybe_build_cleanup () in preceding
code can
@@ -5159,7 +5157,7 @@ cp_coroutine_transform::build_ramp_function ()
= coro_build_and_push_artificial_var (loc, "_Coro_gro", gro_type,
orig_fn_decl, NULL_TREE);
- r = cp_build_init_expr (coro_gro, get_ro);
+ r = cp_build_init_expr (coro_gro, STRIP_REFERENCE_REF (get_ro));
finish_expr_stmt (r);
tree coro_gro_cleanup
= cxx_maybe_build_cleanup (coro_gro, tf_warning_or_error);
@@ -5167,6 +5165,11 @@ cp_coroutine_transform::build_ramp_function ()
push_cleanup (coro_gro, coro_gro_cleanup, /*eh_only*/false);
}
+ /* Initialize the resume_idx_var to 0, meaning "not started". */
+ coro_build_and_push_artificial_var_with_dve
+ (loc, coro_resume_index_id, short_unsigned_type_node, orig_fn_decl,
+ build_zero_cst (short_unsigned_type_node), deref_fp);
+
/* Start the coroutine body. */
r = build_call_expr_loc (fn_start, resumer, 1, coro_fp);
finish_expr_stmt (r);
@@ -5180,7 +5183,8 @@ cp_coroutine_transform::build_ramp_function ()
/* The ramp is done, we just need the return statement, which we
build from
the return object we constructed before we called the function
body. */
- finish_return_stmt (void_ramp_p ? NULL_TREE : coro_gro);
+ r = void_ramp_p ? NULL_TREE : convert_from_reference (coro_gro);
+ finish_return_stmt (r);
if (flag_exceptions)
{
diff --git a/gcc/testsuite/g++.dg/coroutines/pr115908.C b/gcc/
testsuite/g++.dg/coroutines/pr115908.C
index ac27d916de2..d8903748e40 100644
--- a/gcc/testsuite/g++.dg/coroutines/pr115908.C
+++ b/gcc/testsuite/g++.dg/coroutines/pr115908.C
@@ -6,23 +6,26 @@
struct Promise;
-bool promise_live = false;
+int promise_life = 0;
struct Handle : std::coroutine_handle<Promise> {
+
+ /* We now expect the handle to be created after the promise is
destroyed. */
Handle(Promise &p) :
std::coroutine_handle<Promise>(Handle::from_promise(p)) {
- if (!promise_live)
- __builtin_abort ();
#ifdef OUTPUT
- std::cout << "Handle(Promise &)\n";
+ std::cout << "Handle(Promise &) " << promise_life << std::endl;
#endif
- }
- Handle(Promise &&p) :
std::coroutine_handle<Promise>(Handle::from_promise(p)) {
- if (!promise_live)
+ if (promise_life <= 0)
__builtin_abort ();
+ }
+
+ Handle(Promise &&p) :
std::coroutine_handle<Promise>(Handle::from_promise(p)) {
#ifdef OUTPUT
- std::cout << "Handle(Promise &&)\n";
+ std::cout << "Handle(Promise &&) " << promise_life <<
std::endl;
#endif
- }
+ if (promise_life <= 0)
+ __builtin_abort ();
+ }
using promise_type = Promise;
};
@@ -30,46 +33,73 @@ struct Handle : std::coroutine_handle<Promise> {
struct Promise {
Promise() {
#ifdef OUTPUT
- std::cout << "Promise()\n";
+ std::cout << "Promise()" << std::endl;
#endif
- promise_live = true;
+ promise_life++;
}
+
+ Promise(Promise& p){
+#ifdef OUTPUT
+ std::cout << "Promise(Promise&)" << std::endl;
+#endif
+ promise_life++;
+ }
+
~Promise() {
#ifdef OUTPUT
- std::cout << "~Promise()\n";
+ std::cout << "~Promise()" << std::endl;
#endif
- if (!promise_live)
+ if (promise_life <= 0)
__builtin_abort ();
- promise_live = false;
+ promise_life--;
}
+
Promise& get_return_object() noexcept {
#ifdef OUTPUT
- std::cout << "get_return_object()\n";
+ std::cout << "get_return_object() " << promise_life <<
std::endl;
#endif
- if (!promise_live)
+ if (promise_life <= 0)
__builtin_abort ();
return *this;
}
- std::suspend_never initial_suspend() const noexcept { return {}; }
- std::suspend_never final_suspend() const noexcept { return {}; }
+
+ std::suspend_never initial_suspend() const noexcept {
+#ifdef OUTPUT
+ std::cout << "initial_suspend()" << std::endl;
+#endif
+ return {};
+ }
+ std::suspend_never final_suspend() const noexcept {
+#ifdef OUTPUT
+ std::cout << "final_suspend()" << std::endl;
+#endif
+ return {};
+ }
void return_void() const noexcept {
- if (!promise_live)
+ if (!promise_life)
__builtin_abort ();
#ifdef OUTPUT
- std::cout << "return_void()\n";
+ std::cout << "return_void()" << std::endl;
#endif
}
void unhandled_exception() const noexcept {}
};
Handle Coro() {
+
+#ifdef OUTPUT
+ std::cout << "Coro()" << std::endl;
+#endif
co_return;
}
int main() {
- Coro();
- if (promise_live)
+ Coro();
+#ifdef OUTPUT
+ std::cout << "done Coro()" << std::endl;
+#endif
+ if (promise_life)
__builtin_abort ();
return 0;
}
