Re: [PATCH] coroutines: Collect the function body rewrite code.
On 6/27/20 4:13 PM, Iain Sandoe wrote:
Hi,
This is a enabler patch that enables a reasonable approach to
fixing 5 reported PRs (it doesn’t fix anything in its own right).
It has been tested on x86_64-linux, darwin, powerpc64-linux
OK for master / 10.2?
thanks
Iain
OK, yes it was quite a slippery target to hit!
--
The standard describes a rewrite of the body of the user-authored
function (which wraps it in a try-catch block and provides the
initial and final suspend expressions). The exact arrangement of
this was still in flux right up until the WG21 meeting in Prague and
as a consequence was a bit of a moving target.
The net result was a fragmented implementation of the parts of
this rewrite which is now impeding progress in fixing other issues.
This patch collates the rewrite action into a single function and
carries this out earlier.
gcc/cp/ChangeLog:
* coroutines.cc (expand_one_await_expression): Remove
code dealing with initial suspend.
(build_actor_fn): Remove code special-casing initial
and final suspend. Handle the final suspend and marking
of the coroutine as done.
(coro_rewrite_function_body): New.
(bind_expr_find_in_subtree): Remove.
(coro_body_contains_bind_expr_p): Remove.
(morph_fn_to_coro): Split the rewrite of the original
function into coro_rewrite_function_body and call it.
---
gcc/cp/coroutines.cc | 534 +--
1 file changed, 208 insertions(+), 326 deletions(-)
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 54f9cb3b4e4..8e0f0e09b56 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -1573,8 +1573,6 @@ expand_one_await_expression (tree *stmt, tree
*await_expr, void *d)
tree awaiter_calls = TREE_OPERAND (saved_co_await, 3);
tree source = TREE_OPERAND (saved_co_await, 4);
- bool is_initial =
-(source && TREE_INT_CST_LOW (source) == (int) INITIAL_SUSPEND_POINT);
bool is_final = (source
&& TREE_INT_CST_LOW (source) == (int) FINAL_SUSPEND_POINT);
bool needs_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (var));
@@ -1724,16 +1722,6 @@ expand_one_await_expression (tree *stmt, tree
*await_expr, void *d)
resume_label = build_stmt (loc, LABEL_EXPR, resume_label);
append_to_statement_list (resume_label, _list);
- if (is_initial)
-{
- /* Note that we are about to execute the await_resume() for the initial
-await expression. */
- r = build2_loc (loc, MODIFY_EXPR, boolean_type_node, data->i_a_r_c,
- boolean_true_node);
- r = coro_build_cvt_void_expr_stmt (r, loc);
- append_to_statement_list (r, _list);
-}
-
/* This will produce the value (if one is provided) from the co_await
expression. */
tree resume_call = TREE_VEC_ELT (awaiter_calls, 2); /* await_resume(). */
@@ -2102,19 +2090,16 @@ static void
build_actor_fn (location_t loc, tree coro_frame_type, tree actor, tree fnbody,
tree orig, hash_map *param_uses,
hash_map *local_var_uses,
- vec *param_dtor_list, tree initial_await,
- tree final_await, unsigned body_count, tree frame_size)
+ vec *param_dtor_list,
+ tree fs_label, tree resume_fn_field,
+ unsigned body_count, tree frame_size)
{
verify_stmt_tree (fnbody);
/* Some things we inherit from the original function. */
- tree coro_frame_ptr = build_pointer_type (coro_frame_type);
tree handle_type = get_coroutine_handle_type (orig);
tree self_h_proxy = get_coroutine_self_handle_proxy (orig);
tree promise_type = get_coroutine_promise_type (orig);
tree promise_proxy = get_coroutine_promise_proxy (orig);
- tree act_des_fn_type
-= build_function_type_list (void_type_node, coro_frame_ptr, NULL_TREE);
- tree act_des_fn_ptr = build_pointer_type (act_des_fn_type);
/* One param, the coro frame pointer. */
tree actor_fp = DECL_ARGUMENTS (actor);
@@ -2145,21 +2130,15 @@ build_actor_fn (location_t loc, tree coro_frame_type,
tree actor, tree fnbody,
DECL_CONTEXT (continuation) = actor;
BIND_EXPR_VARS (actor_bind) = continuation;
- /* Update the block associated with the outer scope of the orig fn. */
+ /* Link in the block associated with the outer scope of the re-written
+ function body. */
tree first = expr_first (fnbody);
- if (first && TREE_CODE (first) == BIND_EXPR)
-{
- /* We will discard this, since it's connected to the original scope
-nest. */
- tree block = BIND_EXPR_BLOCK (first);
- if (block) /* For this to be missing is probably a bug. */
- {
- gcc_assert (BLOCK_SUPERCONTEXT (block) == NULL_TREE);
- gcc_assert (BLOCK_CHAIN (block) == NULL_TREE);
- BLOCK_SUPERCONTEXT (block) = top_block;
- BLOCK_SUBBLOCKS (top_block) = block;
- }
-}
+ gcc_checking_assert
[PATCH] coroutines: Collect the function body rewrite code.
Hi,
This is a enabler patch that enables a reasonable approach to
fixing 5 reported PRs (it doesn’t fix anything in its own right).
It has been tested on x86_64-linux, darwin, powerpc64-linux
OK for master / 10.2?
thanks
Iain
--
The standard describes a rewrite of the body of the user-authored
function (which wraps it in a try-catch block and provides the
initial and final suspend expressions). The exact arrangement of
this was still in flux right up until the WG21 meeting in Prague and
as a consequence was a bit of a moving target.
The net result was a fragmented implementation of the parts of
this rewrite which is now impeding progress in fixing other issues.
This patch collates the rewrite action into a single function and
carries this out earlier.
gcc/cp/ChangeLog:
* coroutines.cc (expand_one_await_expression): Remove
code dealing with initial suspend.
(build_actor_fn): Remove code special-casing initial
and final suspend. Handle the final suspend and marking
of the coroutine as done.
(coro_rewrite_function_body): New.
(bind_expr_find_in_subtree): Remove.
(coro_body_contains_bind_expr_p): Remove.
(morph_fn_to_coro): Split the rewrite of the original
function into coro_rewrite_function_body and call it.
---
gcc/cp/coroutines.cc | 534 +--
1 file changed, 208 insertions(+), 326 deletions(-)
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index 54f9cb3b4e4..8e0f0e09b56 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -1573,8 +1573,6 @@ expand_one_await_expression (tree *stmt, tree
*await_expr, void *d)
tree awaiter_calls = TREE_OPERAND (saved_co_await, 3);
tree source = TREE_OPERAND (saved_co_await, 4);
- bool is_initial =
-(source && TREE_INT_CST_LOW (source) == (int) INITIAL_SUSPEND_POINT);
bool is_final = (source
&& TREE_INT_CST_LOW (source) == (int) FINAL_SUSPEND_POINT);
bool needs_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (var));
@@ -1724,16 +1722,6 @@ expand_one_await_expression (tree *stmt, tree
*await_expr, void *d)
resume_label = build_stmt (loc, LABEL_EXPR, resume_label);
append_to_statement_list (resume_label, _list);
- if (is_initial)
-{
- /* Note that we are about to execute the await_resume() for the initial
-await expression. */
- r = build2_loc (loc, MODIFY_EXPR, boolean_type_node, data->i_a_r_c,
- boolean_true_node);
- r = coro_build_cvt_void_expr_stmt (r, loc);
- append_to_statement_list (r, _list);
-}
-
/* This will produce the value (if one is provided) from the co_await
expression. */
tree resume_call = TREE_VEC_ELT (awaiter_calls, 2); /* await_resume(). */
@@ -2102,19 +2090,16 @@ static void
build_actor_fn (location_t loc, tree coro_frame_type, tree actor, tree fnbody,
tree orig, hash_map *param_uses,
hash_map *local_var_uses,
- vec *param_dtor_list, tree initial_await,
- tree final_await, unsigned body_count, tree frame_size)
+ vec *param_dtor_list,
+ tree fs_label, tree resume_fn_field,
+ unsigned body_count, tree frame_size)
{
verify_stmt_tree (fnbody);
/* Some things we inherit from the original function. */
- tree coro_frame_ptr = build_pointer_type (coro_frame_type);
tree handle_type = get_coroutine_handle_type (orig);
tree self_h_proxy = get_coroutine_self_handle_proxy (orig);
tree promise_type = get_coroutine_promise_type (orig);
tree promise_proxy = get_coroutine_promise_proxy (orig);
- tree act_des_fn_type
-= build_function_type_list (void_type_node, coro_frame_ptr, NULL_TREE);
- tree act_des_fn_ptr = build_pointer_type (act_des_fn_type);
/* One param, the coro frame pointer. */
tree actor_fp = DECL_ARGUMENTS (actor);
@@ -2145,21 +2130,15 @@ build_actor_fn (location_t loc, tree coro_frame_type,
tree actor, tree fnbody,
DECL_CONTEXT (continuation) = actor;
BIND_EXPR_VARS (actor_bind) = continuation;
- /* Update the block associated with the outer scope of the orig fn. */
+ /* Link in the block associated with the outer scope of the re-written
+ function body. */
tree first = expr_first (fnbody);
- if (first && TREE_CODE (first) == BIND_EXPR)
-{
- /* We will discard this, since it's connected to the original scope
-nest. */
- tree block = BIND_EXPR_BLOCK (first);
- if (block) /* For this to be missing is probably a bug. */
- {
- gcc_assert (BLOCK_SUPERCONTEXT (block) == NULL_TREE);
- gcc_assert (BLOCK_CHAIN (block) == NULL_TREE);
- BLOCK_SUPERCONTEXT (block) = top_block;
- BLOCK_SUBBLOCKS (top_block) = block;
- }
-}
+ gcc_checking_assert (first && TREE_CODE (first) == BIND_EXPR);
+ tree block = BIND_EXPR_BLOCK (first);
+ gcc_checking_assert
