[Bug c++/55753] [C++11][4.7/4.8 Regression] ICE constexpr ctor, tsubst_copy_and_build, at cp/pt.c:14336

[david.abdurachmanov at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55753

--- Comment #4 from David Abdurachmanov <david.abdurachmanov at gmail dot com> 2012-12-24 12:48:01 UTC ---
I did some more testing of the trunk. Compiles fine with r173678 [g++ (GCC)
4.7.0 20110511 (experimental)], but starts ICE'ing with r173679. gcc_assert
(TREE_CONSTANT (t)); (ICE line) was added in r166592 [1]. I tried passing
--enable-checking=none or touching gcc/DEV-PHASE, but bootstrap comparison was
always failing.

I looked at gcc/configure.ac. trunk has DEV-PHASE set to experimental thus
ac_checking_flags=yes, which sets ac_checking=1. If ac_checking_flags=release
then ac_checking= is not set. If ac_checking is set, it defines ENABLE_CHECKING
macro, I believe. That would probably explain why it works for me with 4.7.2
(final).

Probably this is the part [2] causing the ICE.

Merry Christmas in advance!
david

[1]
http://gcc.gnu.org/viewcvs/trunk/gcc/cp/pt.c?r1=166592&r2=166591&pathrev=166592
[2]
http://gcc.gnu.org/viewcvs/trunk/gcc/cp/pt.c?r1=173679&r2=173678&pathrev=173679