coroutines: Use cp_build_init_expr consistently.
Commit Message
Tested on x86_64-darwin19, OK for master?
thanks
Iain
-- >8 --
Now we have the TARGET_EXPR_ELIDING_P flag, it is important to ensure it
is set properly on target exprs. The code here has a mixture of APIs used
to build inits. This patch changes that to use cp_build_init_expr() where
possible, since that handles setting the flag.
---
gcc/cp/coroutines.cc | 25 ++++++++-----------------
1 file changed, 8 insertions(+), 17 deletions(-)
Comments
On 10/11/22 17:58, Iain Sandoe wrote:
> Tested on x86_64-darwin19, OK for master?
> thanks
> Iain
>
> -- >8 --
>
> Now we have the TARGET_EXPR_ELIDING_P flag, it is important to ensure it
> is set properly on target exprs. The code here has a mixture of APIs used
> to build inits. This patch changes that to use cp_build_init_expr() where
> possible, since that handles setting the flag.
Hmm, I wouldn't expect this to be necessary, since cp_build_modify_expr
calls cp_build_init_expr for INIT_EXPR. Perhaps the similarity of the
function names is a trap...
> ---
> gcc/cp/coroutines.cc | 25 ++++++++-----------------
> 1 file changed, 8 insertions(+), 17 deletions(-)
>
> diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
> index 01a3e831ee5..20d309445eb 100644
> --- a/gcc/cp/coroutines.cc
> +++ b/gcc/cp/coroutines.cc
> @@ -1025,8 +1025,7 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind)
> else
> {
> e_proxy = get_awaitable_var (suspend_kind, o_type);
> - o = cp_build_modify_expr (loc, e_proxy, INIT_EXPR, o,
> - tf_warning_or_error);
> + o = cp_build_init_expr (loc, e_proxy, o);
> }
>
> /* I suppose we could check that this is contextually convertible to bool. */
> @@ -2889,8 +2888,7 @@ flatten_await_stmt (var_nest_node *n, hash_set<tree> *promoted,
> gcc_checking_assert (!already_present);
> tree inner = TREE_OPERAND (init, 1);
> gcc_checking_assert (TREE_CODE (inner) != COND_EXPR);
> - init = cp_build_modify_expr (input_location, var, INIT_EXPR, init,
> - tf_warning_or_error);
> + init = cp_build_init_expr (var, init);
> /* Simplify for the case that we have an init containing the temp
> alone. */
> if (t == n->init && n->var == NULL_TREE)
> @@ -3656,8 +3654,7 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d)
> if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
> cond_inner = TREE_OPERAND (cond_inner, 0);
> location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt));
> - tree new_s = cp_build_init_expr (sloc, newvar,
> - cond_inner);
> + tree new_s = cp_build_init_expr (sloc, newvar, cond_inner);
> finish_expr_stmt (new_s);
> SWITCH_STMT_COND (sw_stmt) = newvar;
> /* Now add the switch statement with the condition re-
> @@ -4902,9 +4899,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
> if (flag_exceptions)
> {
> /* This var is now live. */
> - r = build_modify_expr (fn_start, parm.guard_var,
> - boolean_type_node, INIT_EXPR, fn_start,
> - boolean_true_node, boolean_type_node);
> + r = cp_build_init_expr (fn_start, parm.guard_var,
> + boolean_true_node);
> finish_expr_stmt (r);
> }
> }
> @@ -4948,9 +4944,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
> r = coro_build_cvt_void_expr_stmt (r, fn_start);
> finish_expr_stmt (r);
>
> - r = build_modify_expr (fn_start, coro_promise_live, boolean_type_node,
> - INIT_EXPR, fn_start, boolean_true_node,
> - boolean_type_node);
> + r = cp_build_init_expr (fn_start, coro_promise_live, boolean_true_node);
> finish_expr_stmt (r);
>
> promise_dtor
> @@ -5031,8 +5025,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
> NULL_TREE);
> add_decl_expr (gro);
> gro_bind_vars = gro;
> - r = cp_build_modify_expr (input_location, gro, INIT_EXPR, get_ro,
> - tf_warning_or_error);
> + r = cp_build_init_expr (gro, get_ro);
> /* The constructed object might require a cleanup. */
> if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (gro_type))
> {
> @@ -5053,9 +5046,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
> cleanup. */
> if (gro_ret_dtor)
> {
> - r = build_modify_expr (fn_start, coro_gro_live, boolean_type_node,
> - INIT_EXPR, fn_start, boolean_true_node,
> - boolean_type_node);
> + r = cp_build_init_expr (fn_start, coro_gro_live, boolean_true_node);
> finish_expr_stmt (r);
> }
> /* Initialize the resume_idx_var to 0, meaning "not started". */
Hi Jason
> On 11 Oct 2022, at 23:06, Jason Merrill <jason@redhat.com> wrote:
>
> On 10/11/22 17:58, Iain Sandoe wrote:
>> Tested on x86_64-darwin19, OK for master?
>> thanks
>> Iain
>> -- >8 --
>> Now we have the TARGET_EXPR_ELIDING_P flag, it is important to ensure it
>> is set properly on target exprs. The code here has a mixture of APIs used
>> to build inits. This patch changes that to use cp_build_init_expr() where
>> possible, since that handles setting the flag.
>
> Hmm, I wouldn't expect this to be necessary, since cp_build_modify_expr calls cp_build_init_expr for INIT_EXPR.
It seems that path is only taken if the init is a CONSTRUCTOR.
> Perhaps the similarity of the function names is a trap...
not sure exactly what trap you mean.
It seems that on my local set of additional tests (for some of the open prs) there are some
progressions from this change, I will have to track down which change is the cause.
thanks
Iain
>
>> ---
>> gcc/cp/coroutines.cc | 25 ++++++++-----------------
>> 1 file changed, 8 insertions(+), 17 deletions(-)
>> diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
>> index 01a3e831ee5..20d309445eb 100644
>> --- a/gcc/cp/coroutines.cc
>> +++ b/gcc/cp/coroutines.cc
>> @@ -1025,8 +1025,7 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind)
>> else
>> {
>> e_proxy = get_awaitable_var (suspend_kind, o_type);
>> - o = cp_build_modify_expr (loc, e_proxy, INIT_EXPR, o,
>> - tf_warning_or_error);
>> + o = cp_build_init_expr (loc, e_proxy, o);
>> }
>> /* I suppose we could check that this is contextually convertible to bool. */
>> @@ -2889,8 +2888,7 @@ flatten_await_stmt (var_nest_node *n, hash_set<tree> *promoted,
>> gcc_checking_assert (!already_present);
>> tree inner = TREE_OPERAND (init, 1);
>> gcc_checking_assert (TREE_CODE (inner) != COND_EXPR);
>> - init = cp_build_modify_expr (input_location, var, INIT_EXPR, init,
>> - tf_warning_or_error);
>> + init = cp_build_init_expr (var, init);
>> /* Simplify for the case that we have an init containing the temp
>> alone. */
>> if (t == n->init && n->var == NULL_TREE)
>> @@ -3656,8 +3654,7 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d)
>> if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
>> cond_inner = TREE_OPERAND (cond_inner, 0);
>> location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt));
>> - tree new_s = cp_build_init_expr (sloc, newvar,
>> - cond_inner);
>> + tree new_s = cp_build_init_expr (sloc, newvar, cond_inner);
>> finish_expr_stmt (new_s);
>> SWITCH_STMT_COND (sw_stmt) = newvar;
>> /* Now add the switch statement with the condition re-
>> @@ -4902,9 +4899,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>> if (flag_exceptions)
>> {
>> /* This var is now live. */
>> - r = build_modify_expr (fn_start, parm.guard_var,
>> - boolean_type_node, INIT_EXPR, fn_start,
>> - boolean_true_node, boolean_type_node);
>> + r = cp_build_init_expr (fn_start, parm.guard_var,
>> + boolean_true_node);
>> finish_expr_stmt (r);
>> }
>> }
>> @@ -4948,9 +4944,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>> r = coro_build_cvt_void_expr_stmt (r, fn_start);
>> finish_expr_stmt (r);
>> - r = build_modify_expr (fn_start, coro_promise_live, boolean_type_node,
>> - INIT_EXPR, fn_start, boolean_true_node,
>> - boolean_type_node);
>> + r = cp_build_init_expr (fn_start, coro_promise_live, boolean_true_node);
>> finish_expr_stmt (r);
>> promise_dtor
>> @@ -5031,8 +5025,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>> NULL_TREE);
>> add_decl_expr (gro);
>> gro_bind_vars = gro;
>> - r = cp_build_modify_expr (input_location, gro, INIT_EXPR, get_ro,
>> - tf_warning_or_error);
>> + r = cp_build_init_expr (gro, get_ro);
>> /* The constructed object might require a cleanup. */
>> if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (gro_type))
>> {
>> @@ -5053,9 +5046,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>> cleanup. */
>> if (gro_ret_dtor)
>> {
>> - r = build_modify_expr (fn_start, coro_gro_live, boolean_type_node,
>> - INIT_EXPR, fn_start, boolean_true_node,
>> - boolean_type_node);
>> + r = cp_build_init_expr (fn_start, coro_gro_live, boolean_true_node);
>> finish_expr_stmt (r);
>> }
>> /* Initialize the resume_idx_var to 0, meaning "not started". */
>
On 10/11/22 18:17, Iain Sandoe wrote:
> Hi Jason
>
>> On 11 Oct 2022, at 23:06, Jason Merrill <jason@redhat.com> wrote:
>>
>> On 10/11/22 17:58, Iain Sandoe wrote:
>>> Tested on x86_64-darwin19, OK for master?
>>> thanks
>>> Iain
>>> -- >8 --
>>> Now we have the TARGET_EXPR_ELIDING_P flag, it is important to ensure it
>>> is set properly on target exprs. The code here has a mixture of APIs used
>>> to build inits. This patch changes that to use cp_build_init_expr() where
>>> possible, since that handles setting the flag.
>>
>> Hmm, I wouldn't expect this to be necessary, since cp_build_modify_expr calls cp_build_init_expr for INIT_EXPR.
>
> It seems that path is only taken if the init is a CONSTRUCTOR.
If it's not a CONSTRUCTOR it builds a constructor call, which should end
up having the same effect. Certainly cp_build_init_expr is simpler if
it works, so the patch is OK, but if it's necessary that indicates a bug
that should be fixed.
>> Perhaps the similarity of the function names is a trap...
>
> not sure exactly what trap you mean.
The names are close, but cp_build_modify_expr is a lot more complicated;
it handles conversions and overloaded operators.
> It seems that on my local set of additional tests (for some of the open prs) there are some
> progressions from this change, I will have to track down which change is the cause.
>
> thanks
> Iain
>
>>
>>> ---
>>> gcc/cp/coroutines.cc | 25 ++++++++-----------------
>>> 1 file changed, 8 insertions(+), 17 deletions(-)
>>> diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
>>> index 01a3e831ee5..20d309445eb 100644
>>> --- a/gcc/cp/coroutines.cc
>>> +++ b/gcc/cp/coroutines.cc
>>> @@ -1025,8 +1025,7 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind)
>>> else
>>> {
>>> e_proxy = get_awaitable_var (suspend_kind, o_type);
>>> - o = cp_build_modify_expr (loc, e_proxy, INIT_EXPR, o,
>>> - tf_warning_or_error);
>>> + o = cp_build_init_expr (loc, e_proxy, o);
>>> }
>>> /* I suppose we could check that this is contextually convertible to bool. */
>>> @@ -2889,8 +2888,7 @@ flatten_await_stmt (var_nest_node *n, hash_set<tree> *promoted,
>>> gcc_checking_assert (!already_present);
>>> tree inner = TREE_OPERAND (init, 1);
>>> gcc_checking_assert (TREE_CODE (inner) != COND_EXPR);
>>> - init = cp_build_modify_expr (input_location, var, INIT_EXPR, init,
>>> - tf_warning_or_error);
>>> + init = cp_build_init_expr (var, init);
>>> /* Simplify for the case that we have an init containing the temp
>>> alone. */
>>> if (t == n->init && n->var == NULL_TREE)
>>> @@ -3656,8 +3654,7 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d)
>>> if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
>>> cond_inner = TREE_OPERAND (cond_inner, 0);
>>> location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt));
>>> - tree new_s = cp_build_init_expr (sloc, newvar,
>>> - cond_inner);
>>> + tree new_s = cp_build_init_expr (sloc, newvar, cond_inner);
>>> finish_expr_stmt (new_s);
>>> SWITCH_STMT_COND (sw_stmt) = newvar;
>>> /* Now add the switch statement with the condition re-
>>> @@ -4902,9 +4899,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>>> if (flag_exceptions)
>>> {
>>> /* This var is now live. */
>>> - r = build_modify_expr (fn_start, parm.guard_var,
>>> - boolean_type_node, INIT_EXPR, fn_start,
>>> - boolean_true_node, boolean_type_node);
>>> + r = cp_build_init_expr (fn_start, parm.guard_var,
>>> + boolean_true_node);
>>> finish_expr_stmt (r);
>>> }
>>> }
>>> @@ -4948,9 +4944,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>>> r = coro_build_cvt_void_expr_stmt (r, fn_start);
>>> finish_expr_stmt (r);
>>> - r = build_modify_expr (fn_start, coro_promise_live, boolean_type_node,
>>> - INIT_EXPR, fn_start, boolean_true_node,
>>> - boolean_type_node);
>>> + r = cp_build_init_expr (fn_start, coro_promise_live, boolean_true_node);
>>> finish_expr_stmt (r);
>>> promise_dtor
>>> @@ -5031,8 +5025,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>>> NULL_TREE);
>>> add_decl_expr (gro);
>>> gro_bind_vars = gro;
>>> - r = cp_build_modify_expr (input_location, gro, INIT_EXPR, get_ro,
>>> - tf_warning_or_error);
>>> + r = cp_build_init_expr (gro, get_ro);
>>> /* The constructed object might require a cleanup. */
>>> if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (gro_type))
>>> {
>>> @@ -5053,9 +5046,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
>>> cleanup. */
>>> if (gro_ret_dtor)
>>> {
>>> - r = build_modify_expr (fn_start, coro_gro_live, boolean_type_node,
>>> - INIT_EXPR, fn_start, boolean_true_node,
>>> - boolean_type_node);
>>> + r = cp_build_init_expr (fn_start, coro_gro_live, boolean_true_node);
>>> finish_expr_stmt (r);
>>> }
>>> /* Initialize the resume_idx_var to 0, meaning "not started". */
>>
>
> On 12 Oct 2022, at 00:19, Jason Merrill <jason@redhat.com> wrote:
>
> On 10/11/22 18:17, Iain Sandoe wrote:
>> Hi Jason
>>> On 11 Oct 2022, at 23:06, Jason Merrill <jason@redhat.com> wrote:
>>>
>>> On 10/11/22 17:58, Iain Sandoe wrote:
>>>> Now we have the TARGET_EXPR_ELIDING_P flag, it is important to ensure it
>>>> is set properly on target exprs. The code here has a mixture of APIs used
>>>> to build inits. This patch changes that to use cp_build_init_expr() where
>>>> possible, since that handles setting the flag.
>>>
>>> Hmm, I wouldn't expect this to be necessary, since cp_build_modify_expr calls cp_build_init_expr for INIT_EXPR.
You are, of course, right..
>>> Perhaps the similarity of the function names is a trap...
>> not sure exactly what trap you mean.
>
> The names are close, but cp_build_modify_expr is a lot more complicated; it handles conversions and overloaded operators.
This is one of the tricky parts about synthesizing AST from scratch - knowing which API is the “right one” to use in each case - e.g. here: cp_build_modify_expr or cp_build_init_expr or even build2 (INIT_EXPR..
So, it seems that where there could be a mismatch to be diagnosed, I should use cp_build_modify_expr, but maybe in some of the cases where there is no checking needed (e.g. set a guard var to true) it would be appropriate to use one of the simpler forms.
>> It seems that on my local set of additional tests (for some of the open prs) there are some
>> progressions from this change,
That’s a spurious observation, because cp_build_init_expr does not do the diagnostics.
patch withdrawn.
thanks for the explanations,
Iain
@@ -1025,8 +1025,7 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind)
else
{
e_proxy = get_awaitable_var (suspend_kind, o_type);
- o = cp_build_modify_expr (loc, e_proxy, INIT_EXPR, o,
- tf_warning_or_error);
+ o = cp_build_init_expr (loc, e_proxy, o);
}
/* I suppose we could check that this is contextually convertible to bool. */
@@ -2889,8 +2888,7 @@ flatten_await_stmt (var_nest_node *n, hash_set<tree> *promoted,
gcc_checking_assert (!already_present);
tree inner = TREE_OPERAND (init, 1);
gcc_checking_assert (TREE_CODE (inner) != COND_EXPR);
- init = cp_build_modify_expr (input_location, var, INIT_EXPR, init,
- tf_warning_or_error);
+ init = cp_build_init_expr (var, init);
/* Simplify for the case that we have an init containing the temp
alone. */
if (t == n->init && n->var == NULL_TREE)
@@ -3656,8 +3654,7 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d)
if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
cond_inner = TREE_OPERAND (cond_inner, 0);
location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt));
- tree new_s = cp_build_init_expr (sloc, newvar,
- cond_inner);
+ tree new_s = cp_build_init_expr (sloc, newvar, cond_inner);
finish_expr_stmt (new_s);
SWITCH_STMT_COND (sw_stmt) = newvar;
/* Now add the switch statement with the condition re-
@@ -4902,9 +4899,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
if (flag_exceptions)
{
/* This var is now live. */
- r = build_modify_expr (fn_start, parm.guard_var,
- boolean_type_node, INIT_EXPR, fn_start,
- boolean_true_node, boolean_type_node);
+ r = cp_build_init_expr (fn_start, parm.guard_var,
+ boolean_true_node);
finish_expr_stmt (r);
}
}
@@ -4948,9 +4944,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
r = coro_build_cvt_void_expr_stmt (r, fn_start);
finish_expr_stmt (r);
- r = build_modify_expr (fn_start, coro_promise_live, boolean_type_node,
- INIT_EXPR, fn_start, boolean_true_node,
- boolean_type_node);
+ r = cp_build_init_expr (fn_start, coro_promise_live, boolean_true_node);
finish_expr_stmt (r);
promise_dtor
@@ -5031,8 +5025,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
NULL_TREE);
add_decl_expr (gro);
gro_bind_vars = gro;
- r = cp_build_modify_expr (input_location, gro, INIT_EXPR, get_ro,
- tf_warning_or_error);
+ r = cp_build_init_expr (gro, get_ro);
/* The constructed object might require a cleanup. */
if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (gro_type))
{
@@ -5053,9 +5046,7 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
cleanup. */
if (gro_ret_dtor)
{
- r = build_modify_expr (fn_start, coro_gro_live, boolean_type_node,
- INIT_EXPR, fn_start, boolean_true_node,
- boolean_type_node);
+ r = cp_build_init_expr (fn_start, coro_gro_live, boolean_true_node);
finish_expr_stmt (r);
}
/* Initialize the resume_idx_var to 0, meaning "not started". */