gcc-11 builds with --enable-lto cause test segfaults + runtime errors

[mkszuba]

• Version: 16.0.0, 14.16.1, possibly others
• Platform: Linux

What steps will reproduce the bug?

1. Switch active compiler to gcc-11
2. Build node with --enable-lto
   3a. To reproduce test segfault, run cctest
   3b. To reproduce runtime errors, use this build of node to e.g. compile a recent version of Firefox

How often does it reproduce? Is there a required condition?

Every time.

What is the expected behavior?

Node passes tests and runs correctly.

What do you see instead?

See e.g. https://bugs.gentoo.org/787158

Additional information

Enabling LTO for the same node versions works fine with gcc-10.

[mkszuba]

Here is the output of the test suite.

cctest-segfault.log

[addaleax]

@mkszuba Any chance you can use a native debugger to get a backtrace here, or provide binary + coredump?

[mkszuba]

Sure, here you go.
node-14.16.1-cctest_backtrace.log

[janhenke]

Ping this issue still exist and with GCC 11 being used more and more, also more and more people are affected by the lack of possible optimisations.

Is there a chance that someone with more experience can take a look into what is the cause of the problems when building with LTO enabled?

[richardlau]

Does this happen with Node.js >=17.2.0/builds from the master branch? In particular, does #40631 (which fixed #40368) help?

I have already cherry-picked #40631 onto the v16.x-staging and v14.x-staging branches so it should go out in the releases planned for the end of January/beginning of February.

[sapics]

I have confirmed that there are NO ERRORs in gcc-11 + --enable-lto.
Sorry, I have no idea that my test is equivalent to cctest or not.
I have tested as follows.

src: master branch + cherry-pick c6e4596 (#41772)
Platform: Ubuntu 20.04
cpu: Ryzen Threadripper
gcc -v: gcc 11.1.0
test as root with following command

export CFLAGS="-march=native"
export CXXFLAGS="-march=native"
export CPPFLAGS="-march=native"
./configure --experimental-enable-pointer-compression --enable-lto
make -j60
make -j60 test