config: Add -z pack-relative-relocs to LDFLAGS

• config: Use one -Wl in LDFLAGS per logical flag
  This will separate logical flags with whitespace and make it easier to split the flags across multiple lines.

• config: Add -z pack-relative-relocs to LDFLAGS
  This moves relative relocations from the .rela.dyn section into a new .relr.dyn section with a significantly more compact encoding, supported since glibc 2.36, GNU Binutils 2.38 and LLVM 15.

  This can reduce the size of libraries a lot, e.g. the installed size of libphonenumber dropped from about 17 MB to 7 MB.

  For more info, see rfcs!23 (merged).

Interesting...looks promising! MaskRay also has a nice blog post

With my cautious hat on, other distros don't appear to have globally enabled this yet (most notably Fedora). Instincts tell me this could have some potential for breakage if enabled across the board. Some solid testing would be good e.g. rebuild a portion of the distro with this enabled, say [core] + GNOME + Plasma and see if anything breaks. But that's a lot of work and I'm not volunteering

Edit: MaskRay filed FS#72433 back in Oct '21.

Note that glibc has already enabled this for itself (readelf -d /usr/lib/libc.so.6 contains RELR tags).

This should be amended in the RFC for our buildflags.

https://gitlab.archlinux.org/archlinux/rfcs/-/blob/master/rfcs/0003-buildflags.rst?ref_type=heads

added 4 commits

• 69e0e919...54796168 - 2 commits from branch archlinux:master
• 99dc0997 - config: Use one -Wl in LDFLAGS per logical flag
• 56698ed0 - config: Add -z pack-relative-relocs to LDFLAGS

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added 3 commits

• a316b50f - 1 commit from branch archlinux:master
• e2542d9d - config: Use one -Wl in LDFLAGS per logical flag
• 6a064844 - config: Add -z pack-relative-relocs to LDFLAGS

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changed the description

changed milestone to %v1.1.0

added scopeenhancement label

assigned to @anthraxx

added 20 commits

• 6a064844...9a356eae - 18 commits from branch archlinux:master
• 1535a69a - chore(config): Use one -Wl in LDFLAGS per logical flag
• c356995d - feat(config): Add -z pack-relative-relocs to LDFLAGS

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approved this merge request

approved this merge request

merged

mentioned in merge request archlinux/packaging/packages/pacman!6 (merged)

mentioned in issue archlinux/packaging/packages/pacman#21