https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80290
Bug ID: 80290
Summary: g++ uses unreasonable amount of memory compiling
nested string maps
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: andrew at aj dot id.au
Target Milestone: ---
Created attachment 41107
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41107&action=edit
Source file demonstrating bad behaviour
g++ uses an unreasonable amount of memory (greater than 5GB) when compiling the
attached code. A source archive is attached, and the test can be run with
`make`. Testing suggests this issue occurs with x86_64 g++s 5.4 and 6.2 from
Ubuntu Yakkety, and both 6.3 and 7.0.1 built from source. The bug was
originally encountered under a Yocto/Poky build cross-compiling from x86_64 to
ARMv6 (targeting an ARM1176 core).
Alan Modra's tests indicate g++ 4.8 performs better than any of the previously
mentioned versions. Behaviour in clang 3.8 also appears reasonable.
GCCs built from source were built with a configure line derived from Ubuntu
Yakkety's g++ builds, with minor modifications to restrict the supported
languages and architectures, and to change prefixes.
Test case is built with `g++ -std=c++11 fru-gen.ii -o fru-gen.o`
$ ~/gcc/master/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/home/andrew/gcc/master/bin/g++
COLLECT_LTO_WRAPPER=/home/andrew/gcc/master/libexec/gcc/x86_64-linux-gnu/7.0.1/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../configure -v --enable-languages=c,c++
--prefix=/home/andrew/gcc/master --enable-shared --enable-linker-build-id
--without-included-gettext --enable-threads=posix --enable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --disable-browser-plugin --enable-gtk-cairo
--with-arch-directory=amd64 --disable-werror --disable-multilib --with-abi=m64
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu --enable-bootstrap
Thread model: posix
gcc version 7.0.1 20170401 (experimental) (GCC)
