diff options
| author | Jason Merrill <jason@redhat.com> | 2020-03-04 12:08:42 -0500 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2020-03-04 17:32:10 -0500 |
| commit | 6876b269bc7fe6465fedfed87c31e6175992129f (patch) | |
| tree | 932e196928b06bdf75240404f18593556310a575 | |
| parent | 10bbbb591cfe6cac200e926a73f3b8065147ce84 (diff) | |
c++: Fix [[no_unique_address]] and default mem-init [PR90432]
output_constructor doesn't like two consecutive entries with fields at the
same position; let's avoid adding the one for the empty field.
gcc/cp/ChangeLog
2020-03-04 Jason Merrill <jason@redhat.com>
PR c++/90432
* init.c (perform_member_init): Don't do aggregate initialization of
empty field.
* constexpr.c (cx_check_missing_mem_inits): Don't enforce
initialization of empty field.
| -rw-r--r-- | gcc/cp/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/cp/constexpr.c | 3 | ||||
| -rw-r--r-- | gcc/cp/init.c | 5 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/no_unique_address3.C | 16 |
4 files changed, 32 insertions, 0 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 34ff88ee033..254e5a31096 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,11 @@ +2020-03-04 Jason Merrill <jason@redhat.com> + + PR c++/90432 + * init.c (perform_member_init): Don't do aggregate initialization of + empty field. + * constexpr.c (cx_check_missing_mem_inits): Don't enforce + initialization of empty field. + 2020-03-04 Martin Liska <mliska@suse.cz> * method.c: Wrap array in ctor with braces in order diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index c2d44605764..521c87f6210 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -831,6 +831,9 @@ cx_check_missing_mem_inits (tree ctype, tree body, bool complain) /* A flexible array can't be intialized here, so don't complain that it isn't. */ continue; + if (DECL_SIZE (field) && integer_zerop (DECL_SIZE (field))) + /* An empty field doesn't need an initializer. */ + continue; ftype = strip_array_types (ftype); if (type_has_constexpr_default_constructor (ftype)) { diff --git a/gcc/cp/init.c b/gcc/cp/init.c index 61ed3aa7e93..27623cf4db1 100644 --- a/gcc/cp/init.c +++ b/gcc/cp/init.c @@ -865,6 +865,11 @@ perform_member_init (tree member, tree init) } if (init == error_mark_node) return; + if (DECL_SIZE (member) && integer_zerop (DECL_SIZE (member)) + && !TREE_SIDE_EFFECTS (init)) + /* Don't add trivial initialization of an empty base/field, as they + might not be ordered the way the back-end expects. */ + return; /* A FIELD_DECL doesn't really have a suitable lifetime, but make_temporary_var_for_ref_to_temp will treat it as automatic and set_up_extended_ref_temp wants to use the decl in a warning. */ diff --git a/gcc/testsuite/g++.dg/cpp2a/no_unique_address3.C b/gcc/testsuite/g++.dg/cpp2a/no_unique_address3.C new file mode 100644 index 00000000000..07108b8b715 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/no_unique_address3.C @@ -0,0 +1,16 @@ +// PR c++/90432 +// { dg-do compile { target c++11 } } + +struct empty {}; + +struct has_empty { + [[no_unique_address]] empty brace_or_equal_initialized{}; +}; + +struct has_value { + int non_zero = 1; +}; + +struct pair : has_empty, has_value {}; + +pair a; |