c++, coroutines: Remove use of coroutine handle in the frame.
We have been keeping a copy of coroutine_handle<promise> in the state
frame, as it was expected to be efficient to use this to initialize the
argument to await_suspend. This does not turn out to be the case and
intializing the value is obstructive to CGW2563 fixes. This removes
the use.
gcc/cp/ChangeLog:
* coroutines.cc (struct coroutine_info): Update comments.
(struct coro_aw_data): Remove self_handle and add in
information to create the handle in lowering.
(expand_one_await_expression): Build a temporary coroutine
handle.
(build_actor_fn): Remove reference to the frame copy of the
coroutine handle.
(cp_coroutine_transform::wrap_original_function_body): Remove
reference to the frame copy of the coroutine handle.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
(cherry picked from commit 8a3acd8cf449636079acb3d1dfcbcabb074b75af)
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 0443f51..6a7c75e 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -206,11 +206,10 @@
tree traits_type; /* The cached traits type for this function. */
tree handle_type; /* The cached coroutine handle for this function. */
tree self_h_proxy; /* A handle instance that is used as the proxy for the
- one that will eventually be allocated in the coroutine
- frame. */
+ one that will eventually be built in lowering. */
tree promise_proxy; /* Likewise, a proxy promise instance. */
- tree from_address; /* handle_type from_address function. */
- tree return_void; /* The expression for p.return_void() if it exists. */
+ tree from_address; /* handle_type from_address() function. */
+ tree return_void; /* The expression for p.return_void(), if it exists. */
location_t first_coro_keyword; /* The location of the keyword that made this
function into a coroutine. */
@@ -1997,12 +1996,13 @@
tree coro_fp; /* Frame pointer var. */
tree resume_idx; /* This is the index var in the frame. */
tree i_a_r_c; /* initial suspend await_resume() was called if true. */
- tree self_h; /* This is a handle to the current coro (frame var). */
tree cleanup; /* This is where to go once we complete local destroy. */
tree cororet; /* This is where to go if we suspend. */
tree corocont; /* This is where to go if we continue. */
tree dispatch; /* This is where we go if we restart the dispatch. */
tree conthand; /* This is the handle for a continuation. */
+ tree handle_type; /* Handle type for this coroutine... */
+ tree hfa_m; /* ... and handle.from_address() for this. */
unsigned index; /* This is our current resume index. */
};
@@ -2120,6 +2120,18 @@
tree suspend = TREE_VEC_ELT (awaiter_calls, 1); /* await_suspend(). */
tree susp_type = TREE_TYPE (suspend);
+ tree susp_call = suspend;
+ if (TREE_CODE (suspend) == TARGET_EXPR)
+ susp_call = TARGET_EXPR_INITIAL (suspend);
+ gcc_checking_assert (TREE_CODE (susp_call) == CALL_EXPR);
+ tree dummy_ch = build_dummy_object (data->handle_type);
+ r = fold_convert (build_pointer_type (void_type_node), data->coro_fp);
+ vec<tree, va_gc> *args = make_tree_vector_single (r);
+ tree hfa = cp_fold_rvalue (
+ build_new_method_call (dummy_ch, data->hfa_m, &args, NULL_TREE,
+ LOOKUP_NORMAL, NULL, tf_warning_or_error));
+ release_tree_vector (args);
+ CALL_EXPR_ARG (susp_call, call_expr_nargs (susp_call) - 1) = hfa;
bool is_cont = false;
/* NOTE: final suspend can't resume; the "resume" label in that case
@@ -2601,23 +2613,6 @@
/* Now we start building the rewritten function body. */
add_stmt (build_stmt (loc, LABEL_EXPR, actor_begin_label));
- /* actor's coroutine 'self handle'. */
- tree ash = coro_build_frame_access_expr (actor_frame, coro_self_handle_id,
- false, tf_warning_or_error);
- /* So construct the self-handle from the frame address. */
- tree hfa_m = get_coroutine_from_address (orig);
- /* Should have been set earlier by coro_promise_type_found_p. */
- gcc_assert (hfa_m);
-
- tree r = build1 (CONVERT_EXPR, build_pointer_type (void_type_node), actor_fp);
- vec<tree, va_gc> *args = make_tree_vector_single (r);
- tree hfa = build_new_method_call (ash, hfa_m, &args, NULL_TREE, LOOKUP_NORMAL,
- NULL, tf_warning_or_error);
- r = cp_build_init_expr (ash, hfa);
- r = coro_build_cvt_void_expr_stmt (r, loc);
- add_stmt (r);
- release_tree_vector (args);
-
/* Now we know the real promise, and enough about the frame layout to
decide where to put things. */
@@ -2632,7 +2627,7 @@
add_stmt (fnbody);
/* Now do the tail of the function; first cleanups. */
- r = build_stmt (loc, LABEL_EXPR, del_promise_label);
+ tree r = build_stmt (loc, LABEL_EXPR, del_promise_label);
add_stmt (r);
/* Destructors for the things we built explicitly.
@@ -2701,6 +2696,12 @@
gcc_checking_assert (maybe_cleanup_point_expr_void (r) == r);
add_stmt (r);
+ /* How to construct the handle for this coroutine from the frame address. */
+ tree hfa_m = get_coroutine_from_address (orig);
+ /* Should have been set earlier by coro_promise_type_found_p. */
+ gcc_assert (hfa_m);
+ tree handle_type = TREE_TYPE (get_coroutine_self_handle_proxy (orig));
+
/* We've now rewritten the tree and added the initial and final
co_awaits. Now pass over the tree and expand the co_awaits. */
tree i_a_r_c = NULL_TREE;
@@ -2709,8 +2710,9 @@
false, tf_warning_or_error);
coro_aw_data data = {actor, actor_fp, resume_idx_var, i_a_r_c,
- ash, del_promise_label, ret_label,
- continue_label, restart_dispatch_label, continuation, 2};
+ del_promise_label, ret_label,
+ continue_label, restart_dispatch_label, continuation,
+ handle_type, hfa_m, 2};
cp_walk_tree (&actor_body, await_statement_expander, &data, NULL);
BIND_EXPR_BODY (actor_bind) = pop_stmt_list (actor_body);
@@ -4441,16 +4443,6 @@
var_list = promise;
add_decl_expr (promise);
- /* We need a handle to this coroutine, which is passed to every
- await_suspend(). This was created on demand when parsing we now link it
- into our scope. */
- var = get_coroutine_self_handle_proxy (orig_fn_decl);
- DECL_CONTEXT (var) = orig_fn_decl;
- DECL_SOURCE_LOCATION (var) = loc;
- DECL_CHAIN (var) = var_list;
- var_list = var;
- add_decl_expr (var);
-
/* If we have function parms, then these will be copied to the coroutine
frame as per [dcl.fct.def.coroutine] / 13.
Here, we create a local (proxy) variable for each parm, since the original
@@ -5302,7 +5294,6 @@
bool _Coro_frame_needs_free; free the coro frame mem if set.
bool _Coro_i_a_r_c; [dcl.fct.def.coroutine] / 5.3
short _Coro_resume_index;
- handle_type _Coro_self_handle;
parameter copies (were required).
local variables saved (including awaitables)
(maybe) trailing space.
