Include linker generated symbol in default defined set #9416
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daniel-grumberg
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rconnell9
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@swift-ci please test |
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| package init() { | ||
| self.defined = [] | ||
| self.defined = ["_GLOBAL_OFFSET_TABLE_"] |
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Can we leave a comment here why we include this?
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I have since found a bit more information about this. The PR has been updated to point to lld's source code (which provides a list of automatically defined symbols) as well as using the full list to avoid issues in the future hopefully.
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It seems like `_GLOBAL_OFFSET_TABLE_` is defined by the linker without being present in any object file on x86_64. There are a few other symbols that the linker automatically defines although we haven't run into issues with them. I am including the full list I gathered from lld's source code [1] by default. [1] https://github.com/llvm/llvm-project/blob/177e38286cd61a7b5a968636e1f147f128dd25a2/lld/ELF/Config.h#L632
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@swift-ci please test |
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Errors here seem unrelated... |
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What problem is this change solving? This list will also be different on different platforms, compilers, architectures, etc.; how are we accounting for that? |
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The problem that I ran into is that I build a static library in a
The GTO is not a problematic symbol here since it will get resolved at link time. |
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Generally there are few well defined symbols that are expected to be inserted in the final binary by the linker, like |
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@swift-ci please test |
It seems like
_GLOBAL_OFFSET_TABLE_is defined by the linker without being present in any object file on x86_64.