Since we're only running the ObjCContractPass via the one pass manager in codegen, there's actually no real need to add the --[no-]lto-legacy-pass-manager flags in this diff. But it probably doesn't hurt to leave it in, along with the test, just to make sure that any future migrations to the non-legacy PM don't break behavior

update

run pass right before codegen via a config hook

add passes at the end of the pipeline

use cast<>

Since we emit diagnostics for undefineds in Writer::scanRelocations()

rebase with stacked diff

rephrase

update bss.s test

minor update

Thanks! Will do that in the future.

fix test

update

nice work!

looks pretty good!

rebase

rebase

reorganize order files at bottom of test

lgtm

line wrapping

put back TODO

Should we have a test?

unbreak debug build

Nit: Commit title seems to indicate that we are adding support for paired relocs in this diff, but it seems like this diff is just paving the way for adding that support. Might be worth rephrasing... could also tag with [nfc] to make it explicit.

made quite a few changes, so please have another look :)

use enum for weakref state

make non-weakness take priority

Re bind opcodes: I found http://www.m4b.io/reverse/engineering/mach/binaries/2015/03/29/mach-binaries.html to be a good resource when I was starting out. Particularly the "Mach Import Bind FSA" section.

lgtm

Simple is good :)

lgtm

lgtm

verify that we only re-export top-level frameworks

And yup, the snapshot arguments look similar to our --reproduce

There's a comment in ld64 that says

@thakis I'm unable to properly test PR48511 as the CoreGraphics on my local system seems to have a slightly different set of symbols (despite it being version 10.15.7 too). However, the binary is now trying to import the symbol from CoreGraphics rather than ApplicationServices, so I think this diff is on the right track.