(resending, this didn’t appear to make it to the list)
Hi,
I had implemented a move out of rvalue refs for such ramp values (since
these are most likely to be dangling references). However this does cause
a divergence with the clang implementation - and the patch fixes that.
tested on x86_64,powerpc64-linux, x86_64-darwin
OK for master?
OK for 10.2?
thanks
Iain
-------
Adjust to handle rvalue refs the same way as clang, and to correct
the handling of moves when a copy CTOR is present. This is one area
where we could make things easier for the end-user (as was implemented
before this change), however there needs to be agreement about when the
full statement containing a coroutine call ends (i.e. when the ramp
terminates or when the coroutine terminates).
gcc/cp/ChangeLog:
PR c++/95350
* coroutines.cc (struct param_info): Remove rv_ref field.
(build_actor_fn): Remove specifial rvalue ref handling.
(morph_fn_to_coro): Likewise.
gcc/testsuite/ChangeLog:
PR c++/95350
* g++.dg/coroutines/torture/func-params-08.C: Adjust test to
reflect that all rvalue refs are dangling.
* g++.dg/coroutines/torture/func-params-09-awaitable-parms.C:
Likewise.
* g++.dg/coroutines/pr95350.C: New test.
---
gcc/cp/coroutines.cc | 41 +++++--------------
gcc/testsuite/g++.dg/coroutines/pr95350.C | 28 +++++++++++++
.../coroutines/torture/func-params-08.C | 11 ++---
.../torture/func-params-09-awaitable-parms.C | 11 ++---
4 files changed, 50 insertions(+), 41 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/coroutines/pr95350.C
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 969f4a66f2f..8746927577a 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -1807,7 +1807,6 @@ struct param_info
tree frame_type; /* The type used to represent this parm in the frame. */
tree orig_type; /* The original type of the parm (not as passed). */
bool by_ref; /* Was passed by reference. */
- bool rv_ref; /* Was an rvalue reference. */
bool pt_ref; /* Was a pointer to object. */
bool trivial_dtor; /* The frame type has a trivial DTOR. */
bool this_ptr; /* Is 'this' */
@@ -2077,12 +2076,6 @@ build_actor_fn (location_t loc, tree coro_frame_type,
tree actor, tree fnbody,
if (parm.pt_ref)
fld_idx = build1_loc (loc, CONVERT_EXPR, TREE_TYPE (arg), fld_idx);
- /* We expect an rvalue ref. here. */
- if (parm.rv_ref)
- fld_idx = convert_to_reference (DECL_ARG_TYPE (arg), fld_idx,
- CONV_STATIC, LOOKUP_NORMAL,
- NULL_TREE, tf_warning_or_error);
-
int i;
tree *puse;
FOR_EACH_VEC_ELT (*parm.body_uses, i, puse)
@@ -3770,15 +3763,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree
*destroyer)
if (actual_type == NULL_TREE)
actual_type = error_mark_node;
parm.orig_type = actual_type;
- parm.by_ref = parm.rv_ref = parm.pt_ref = false;
- if (TREE_CODE (actual_type) == REFERENCE_TYPE
- && TYPE_REF_IS_RVALUE (DECL_ARG_TYPE (arg)))
- {
- parm.rv_ref = true;
- actual_type = TREE_TYPE (actual_type);
- parm.frame_type = actual_type;
- }
- else if (TREE_CODE (actual_type) == REFERENCE_TYPE)
+ parm.by_ref = parm.pt_ref = false;
+ if (TREE_CODE (actual_type) == REFERENCE_TYPE)
{
/* If the user passes by reference, then we will save the
pointer to the original. As noted in
@@ -3786,16 +3772,12 @@ morph_fn_to_coro (tree orig, tree *resumer, tree
*destroyer)
referenced item ends and then the coroutine is resumed,
we have UB; well, the user asked for it. */
actual_type = build_pointer_type (TREE_TYPE (actual_type));
- parm.frame_type = actual_type;
parm.pt_ref = true;
}
else if (TYPE_REF_P (DECL_ARG_TYPE (arg)))
- {
- parm.by_ref = true;
- parm.frame_type = actual_type;
- }
- else
- parm.frame_type = actual_type;
+ parm.by_ref = true;
+
+ parm.frame_type = actual_type;
parm.this_ptr = is_this_parameter (arg);
if (lambda_p)
@@ -4170,17 +4152,16 @@ morph_fn_to_coro (tree orig, tree *resumer, tree
*destroyer)
}
else if (parm.by_ref)
vec_safe_push (promise_args, fld_idx);
- else if (parm.rv_ref)
- vec_safe_push (promise_args, rvalue (fld_idx));
else
vec_safe_push (promise_args, arg);
if (TYPE_NEEDS_CONSTRUCTING (parm.frame_type))
{
vec<tree, va_gc> *p_in;
- if (parm.by_ref
- && classtype_has_non_deleted_move_ctor (parm.frame_type)
- && !classtype_has_non_deleted_copy_ctor (parm.frame_type))
+ if (CLASS_TYPE_P (parm.frame_type)
+ && classtype_has_non_deleted_move_ctor (parm.frame_type))
+ p_in = make_tree_vector_single (move (arg));
+ else if (lvalue_p (arg))
p_in = make_tree_vector_single (rvalue (arg));
else
p_in = make_tree_vector_single (arg);
@@ -4193,9 +4174,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree
*destroyer)
}
else
{
- if (parm.rv_ref)
- r = convert_from_reference (arg);
- else if (!same_type_p (parm.frame_type, DECL_ARG_TYPE (arg)))
+ if (!same_type_p (parm.frame_type, DECL_ARG_TYPE (arg)))
r = build1_loc (DECL_SOURCE_LOCATION (arg), CONVERT_EXPR,
parm.frame_type, arg);
else
diff --git a/gcc/testsuite/g++.dg/coroutines/pr95350.C
b/gcc/testsuite/g++.dg/coroutines/pr95350.C
new file mode 100644
index 00000000000..1915032c471
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr95350.C
@@ -0,0 +1,28 @@
+#if __has_include(<coroutine>)
+#include <coroutine>
+#else
+#include <experimental/coroutine>
+namespace std { using namespace experimental; }
+#endif
+#include <utility>
+
+struct task {
+ struct promise_type {
+ task get_return_object();
+ void return_void();
+ void unhandled_exception();
+ std::suspend_always initial_suspend() noexcept;
+ std::suspend_always final_suspend() noexcept;
+ };
+};
+
+struct move_only {
+ move_only();
+ move_only(const move_only&) = delete;
+ move_only(move_only&) = delete;
+ move_only(move_only&&) = default;
+};
+
+task f(move_only x) {
+ co_return;
+}
diff --git a/gcc/testsuite/g++.dg/coroutines/torture/func-params-08.C
b/gcc/testsuite/g++.dg/coroutines/torture/func-params-08.C
index c166745e052..cce1521b226 100644
--- a/gcc/testsuite/g++.dg/coroutines/torture/func-params-08.C
+++ b/gcc/testsuite/g++.dg/coroutines/torture/func-params-08.C
@@ -69,8 +69,9 @@ my_coro (Foo t_lv, Foo& t_ref, Foo&& t_rv_ref)
PRINT ("my_coro 1");
sum += co_await t_ref;
PRINT ("my_coro 2");
- sum += co_await t_rv_ref;
- PRINT ("my_coro 3");
+ // This can't work for the rvalue ref, it's always dangling.
+ //sum += co_await t_rv_ref;
+ //PRINT ("my_coro 3");
co_return sum;
}
@@ -90,17 +91,17 @@ int main ()
// now do the three co_awaits.
while(!x.handle.done())
x.handle.resume();
- PRINT ("main: after resuming 3 co_awaits");
+ PRINT ("main: after resuming 2 co_awaits");
/* Now we should have the co_returned value. */
int y = x.handle.promise().get_value();
- if (y != 14)
+ if (y != 10)
{
PRINTF ("main: wrong result (%d).", y);
abort ();
}
- if (regular != 3 || copy != 1 || move != 1)
+ if (regular != 3 || copy != 0 || move != 1)
{
PRINTF ("main: unexpected ctor use (R:%d, C:%d, M:%d)\n",
regular, copy, move);
diff --git
a/gcc/testsuite/g++.dg/coroutines/torture/func-params-09-awaitable-parms.C
b/gcc/testsuite/g++.dg/coroutines/torture/func-params-09-awaitable-parms.C
index 7d376b91f13..81430bf4d54 100644
--- a/gcc/testsuite/g++.dg/coroutines/torture/func-params-09-awaitable-parms.C
+++ b/gcc/testsuite/g++.dg/coroutines/torture/func-params-09-awaitable-parms.C
@@ -62,8 +62,9 @@ my_coro (FooAwaitable t_lv, FooAwaitable& t_ref,
FooAwaitable&& t_rv_ref)
PRINT ("my_coro 1");
sum += co_await t_ref;
PRINT ("my_coro 2");
- sum += co_await t_rv_ref;
- PRINT ("my_coro 3");
+ // This can't work for the rvalue ref, it's always dangling.
+ //sum += co_await t_rv_ref;
+ //PRINT ("my_coro 3");
co_return sum;
}
@@ -83,17 +84,17 @@ int main ()
// now do the three co_awaits.
while(!x.handle.done())
x.handle.resume();
- PRINT ("main: after resuming 3 co_awaits");
+ PRINT ("main: after resuming 2 co_awaits");
/* Now we should have the co_returned value. */
int y = x.handle.promise().get_value();
- if (y != 14)
+ if (y != 10)
{
PRINTF ("main: wrong result (%d).", y);
abort ();
}
- if (regular != 3 || copy != 1 || move != 1)
+ if (regular != 3 || copy != 0 || move != 1)
{
PRINTF ("main: unexpected ctor use (R:%d, C:%d, M:%d)\n",
regular, copy, move);
--
2.24.1
