2021-09-25 09:39:30 +08:00
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==================
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LD64 vs LLD-MACHO
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==================
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This doc lists all significant deliberate differences in behavior between LD64 and LLD-MachO.
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2022-01-20 08:30:52 +08:00
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String literal deduplication
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****************************
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LD64 always deduplicates string literals. LLD only does it when the `--icf=` or
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the `--deduplicate-literals` flag is passed. Omitting deduplication by default
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ensures that our link is as fast as possible. However, it may also break some
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programs which have (incorrectly) relied on string deduplication always
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2022-01-20 15:59:12 +08:00
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occurring. In particular, programs which compare string literals via pointer
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2022-01-20 08:30:52 +08:00
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equality must be fixed to use value equality instead.
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2022-01-15 15:06:13 +08:00
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``-no_deduplicate`` Flag
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**********************
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- LD64:
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* This turns off ICF (deduplication pass) in the linker.
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- LLD
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* This turns off ICF and string merging in the linker.
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2021-09-25 09:39:30 +08:00
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ObjC symbols treatment
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**********************
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There are differences in how LLD and LD64 handle ObjC symbols loaded from archives.
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- LD64:
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2021-11-15 09:17:08 +08:00
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* Duplicate ObjC symbols from the same archives will not raise an error. LD64 will pick the first one.
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2021-09-25 09:39:30 +08:00
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* Duplicate ObjC symbols from different archives will raise a "duplicate symbol" error.
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- LLD:
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* Duplicate symbols, regardless of which archives they are from, will raise errors.
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