Building with "-flto=auto" causes apps to crash

[etam]

In openSUSE all packages have by default enabled LTO (but in cases like this it can be easily disabled). Fortunately this is caught by the tests, because helpers/helper_accept_no_peer_addr crashes and a test fails.

[aszlig]

This is probably because we're using a custom --version-script:

ip2unix/meson.build

Lines 85 to 92 in 1083369

	gen_ldscript = [python, script_gensyms, '--ldscript']
	ldscript = custom_target('ldscript', input: lib_sources, output: 'ldscript',
	command: gen_ldscript + gen_extra_args, capture: true)
	lib_ldflags += [
	'-Wl,--version-script,@0@'.format(sym_map.full_path()),
	ldscript.full_path()
	]

[aszlig]

Okay, just tested this and it's not because of the --version-script, investigating...

[aszlig]

Sooo, this essentially boils down to a nullptr dereference because the symbols actually resolve to null:

With LTO:

$ nm -D result/lib/libip2unix.so | grep socket
0000000000000000 A socket

Without LTO:

$ nm -D result/lib/libip2unix.so | grep socket
000000000000fed0 T socket

[aszlig]

Okay, backtracking on what I wrote earlier, it is the linker script indeed. I accidentally run a isolated test which ran into essentially a no-op without the linker script.