[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 Jason Merrill changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED Target Milestone|--- |7.0 --- Comment #7 from Jason Merrill --- Fixed for GCC 7.
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 --- Comment #6 from Jason Merrill --- Author: jason Date: Sat Oct 15 21:25:55 2016 New Revision: 241204 URL: https://gcc.gnu.org/viewcvs?rev=241204&root=gcc&view=rev Log: PR c++/77945 - constexpr and trivial copy * constexpr.c (maybe_simplify_trivial_copy): New. (cxx_eval_store_expression): Call it. * call.c (build_over_call): Use unsigned char for trivial copy. Added: trunk/gcc/testsuite/g++.dg/cpp0x/constexpr-trivial2.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/call.c trunk/gcc/cp/constexpr.c
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 Jason Merrill changed: What|Removed |Added Status|NEW |ASSIGNED CC||jason at gcc dot gnu.org Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org --- Comment #5 from Jason Merrill --- Yeah, implementing trivial copy with the equivalent of memcpy is fine normally, but not in constexpr evaluation.
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945
Ville Voutilainen changed:
What|Removed |Added
CC||jason at redhat dot com,
||ville.voutilainen at gmail dot
com
--- Comment #4 from Ville Voutilainen ---
Another test:
struct T
{
int x = 0;
bool y = 0;
constexpr T() {}
};
int main()
{
constexpr T t = (T{} = T{});
}
prog.cc: In function 'int main()':
prog.cc:10:31: error: accessing value of '' through a 'char [5]'
glvalue in a constant expression
constexpr T t = (T{} = T{});
^
That looks rather bad.
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 --- Comment #3 from Eric Fiselier --- > if the type contains trailing padding bytes (but one bytes between members). The last bit is nonsense. I meant to say that padding between members seemed OK.
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 Jonathan Wakely changed: What|Removed |Added Known to work|5.4.0, 6.2.0| Summary|[7 Regression] GCC |GCC generates invalid |generates invalid constexpr |constexpr copy/move |copy/move assignment|assignment operators for |operators for types with|types with trailing |trailing padding. |padding. --- Comment #2 from Jonathan Wakely --- (In reply to Jonathan Wakely from comment #1) > 5 and 6 compile it happily. Ugh, no they don't, sorry, I was compiling the wrong thing. 5 ICEs, 6 has the same error as 7.
[Bug c++/77945] GCC generates invalid constexpr copy/move assignment operators for types with trailing padding.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77945 Jonathan Wakely changed: What|Removed |Added Keywords||wrong-code Status|UNCONFIRMED |NEW Last reconfirmed||2016-10-12 Ever confirmed|0 |1
