[Bug c++/70001] New: Infinity compilation time

["cdkrot at yandex dot ru" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70001

            Bug ID: 70001
           Summary: Infinity compilation time
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cdkrot at yandex dot ru
  Target Milestone: ---

Created attachment 37814
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37814&action=edit
(Sample code to produce bug).

I've found the program which compilation time is infinity (at least > 30 min).

This code contains few std::array<std::complex>'s of big size, and i believe,
that this is the cause of the problem, because after replacing std::array to
C-style arrays problem is gone.

This code is attached, the process of compilation looks like this:
* Compiler isn't printing anything for few minutes.
* Slowly, the compilation errors arise (this code contains few minor typos)
* Compiler sleeps for infinity.

I was using following compilation line: "g++ -Wall -Wextra -std=c++11 file.cpp
-o file"

Running with "time g++ ..." shows, that most part of this time the compiler is
sleeping.
E.g:
* Total time (24min) // killed process after this
* Usr time (< 0.1s)
* Sys time (< 0.1s)

G++ -v:
Using built-in specs.
COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/5.3.0/g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/5.3.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /var/tmp/portage/sys-devel/gcc-5.3.0/work/gcc-5.3.0/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/5.3.0
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.3.0
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.3.0/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.3.0/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/5.3.0/python
--enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt
--disable-werror --with-system-zlib --enable-nls --without-included-gettext
--enable-checking=release --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo 5.3.0 p1.0, pie-0.6.5' --enable-libstdcxx-time
--enable-shared --enable-threads=posix --enable-__cxa_atexit
--enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64
--disable-altivec --disable-fixed-point --enable-targets=all --disable-libgcj
--enable-libgomp --disable-libmudflap --disable-libssp --disable-libcilkrts
--enable-lto --without-isl --enable-libsanitizer
Thread model: posix
gcc version 5.3.0 (Gentoo 5.3.0 p1.0, pie-0.6.5)