Stop marking reflection metadata sections as 'no_dead_strip' on Darwin #41224
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@swift-ci please test |
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Should be safe to do this now. Thanks Kuba! |
jckarter
approved these changes
Feb 7, 2022
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I'm trying to expand dead-strippability to reflection metadata, part of the solution is #40853, this is another part -- currently IRGen marks all reflection metadata sections as 'no_dead_strip' (with a Darwin linker specific attribute). This seems unnecessarily conservative, and there seems to be no good reason why we need these entire sections to opt out of dead-strippability: The globals should either be "alive" (referenced by other globals/code), or if there's situations where there's actually a un-referenced global that still needs to survive into final binaries, we should use llvm.used on that particular global. Furthermore, we already do not use the equivalent of a section-wide dead-strippability opt-out for non-Mach-O targets, and also I tried to dig up why 'no_dead_strip' was added in git history, but I couldn't find anything -- seems like this has always been that way, with no explanation why.