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| author | Marek Polacek <polacek@redhat.com> | 2024-05-22 16:28:02 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2024-05-28 14:28:18 -0400 |
| commit | 5bc731b83b51910dc7f7cacddb4257a16d62ee38 (patch) | |
| tree | af6b604ca4b5e5f808715e00dfa09baf1b429481 /gcc | |
| parent | c0d78289fcd9c04110907f8cad90d7e1e5c55a44 (diff) | |
| download | gcc-5bc731b83b51910dc7f7cacddb4257a16d62ee38.zip gcc-5bc731b83b51910dc7f7cacddb4257a16d62ee38.tar.gz gcc-5bc731b83b51910dc7f7cacddb4257a16d62ee38.tar.bz2 | |
c++: mark TARGET_EXPRs for function arguments eliding [PR114707]
Coming back to our discussion in
<https://gcc.gnu.org/pipermail/gcc-patches/2024-April/649426.html>:
TARGET_EXPRs that initialize a function argument are not marked
TARGET_EXPR_ELIDING_P even though gimplify_arg drops such TARGET_EXPRs
on the floor. To work around it, I added a pset to
replace_placeholders_for_class_temp_r, but it would be best to just rely
on TARGET_EXPR_ELIDING_P.
PR c++/114707
gcc/cp/ChangeLog:
* call.cc (convert_for_arg_passing): Call set_target_expr_eliding.
* typeck2.cc (replace_placeholders_for_class_temp_r): Don't use pset.
(digest_nsdmi_init): Call cp_walk_tree_without_duplicates instead of
cp_walk_tree.
Reviewed-by: Jason Merrill <jason@redhat.com>
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/call.cc | 4 | ||||
| -rw-r--r-- | gcc/cp/typeck2.cc | 20 |
2 files changed, 8 insertions, 16 deletions
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 886760a..85536fc 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -9437,6 +9437,10 @@ convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain) if (complain & tf_warning) warn_for_address_of_packed_member (type, val); + /* gimplify_arg elides TARGET_EXPRs that initialize a function argument. */ + if (SIMPLE_TARGET_EXPR_P (val)) + set_target_expr_eliding (val); + return val; } diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc index 06bad4d..7782f38 100644 --- a/gcc/cp/typeck2.cc +++ b/gcc/cp/typeck2.cc @@ -1409,16 +1409,14 @@ digest_init_flags (tree type, tree init, int flags, tsubst_flags_t complain) in the context of guaranteed copy elision). */ static tree -replace_placeholders_for_class_temp_r (tree *tp, int *, void *data) +replace_placeholders_for_class_temp_r (tree *tp, int *, void *) { tree t = *tp; - auto pset = static_cast<hash_set<tree> *>(data); /* We're looking for a TARGET_EXPR nested in the whole expression. */ if (TREE_CODE (t) == TARGET_EXPR /* That serves as temporary materialization, not an initializer. */ - && !TARGET_EXPR_ELIDING_P (t) - && !pset->add (t)) + && !TARGET_EXPR_ELIDING_P (t)) { tree init = TARGET_EXPR_INITIAL (t); while (TREE_CODE (init) == COMPOUND_EXPR) @@ -1433,16 +1431,6 @@ replace_placeholders_for_class_temp_r (tree *tp, int *, void *data) gcc_checking_assert (!find_placeholders (init)); } } - /* TARGET_EXPRs initializing function arguments are not marked as eliding, - even though gimplify_arg drops them on the floor. Don't go replacing - placeholders in them. */ - else if (TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == AGGR_INIT_EXPR) - for (int i = 0; i < call_expr_nargs (t); ++i) - { - tree arg = get_nth_callarg (t, i); - if (TREE_CODE (arg) == TARGET_EXPR && !TARGET_EXPR_ELIDING_P (arg)) - pset->add (arg); - } return NULL_TREE; } @@ -1490,8 +1478,8 @@ digest_nsdmi_init (tree decl, tree init, tsubst_flags_t complain) temporary materialization does not occur when initializing an object from a prvalue of the same type, therefore we must not replace the placeholder with a temporary object so that it can be elided. */ - hash_set<tree> pset; - cp_walk_tree (&init, replace_placeholders_for_class_temp_r, &pset, nullptr); + cp_walk_tree_without_duplicates (&init, replace_placeholders_for_class_temp_r, + nullptr); return init; } |