Bug 15231

Created attachment 9451 [details]
quick fix

gcc --help -v 2>&1 | grep ffunction-sections

This should display the option with description.
But with buildroot gcc>=10 with RELRO protection configured to Partial or Full, this doesn't work (doesn't display anything).
So affected buildroots are with versions >=2020.11.2
You can check this with bootlin compilers with buildroot>=2021.11

The cause of this is:

1) from gcc 10, the following doesn't work:
gcc -Wl,--some-flag --help -v 2>&1 | grep ffunction-section

I created a bug report:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108328

2) toolchain-wrapper with BR2_RELRO_PARTIAL or BR2_RELRO_FULL adds -Wl,-z,relro linker flags which trigger this

now, BR2_RELRO_PARTIAL or BR2_RELRO_FULL are the default since 2021.05.

Moreover, this causes the python and python3 package to compile without the -fwrapv option, because python detects it using the: gcc --help -v 2>&1 | grep fwrapv

This is just one example that I stumbled upon, I think this can cause problems in general, and in other packages that do these kinds of checks.

I attached a quick fix patch (should I send it to the mailing list too?), but feel free to comment on the gcc bug report I created.