commit | 99e7350235055654aaa923701bf36adaf01739d0 | [log] [tgz] |
---|---|---|
author | Fangrui Song <i@maskray.me> | Wed Apr 24 00:02:21 2024 |
committer | GitHub <noreply@github.com> | Wed Apr 24 00:02:21 2024 |
tree | 3ca5bfe2b7d20cd4ee35df6fd9cc5244863d29db | |
parent | 9c4735e9b3be717eaf1ea524842b5968bf2c6513 [diff] |
IRSymTab: Record _GLOBAL_OFFSET_TABLE_ for ELF x86 In ELF, relocatable files generated for x86-32 and some code models of x86-64 (medium, large) may reference the special symbol `_GLOBAL_OFFSET_TABLE_` that is not used in the IR. In an LTO link, if there is no regular relocatable file referencing the special symbol, the linker may not define the symbol and lead to a spurious "undefined symbol" error. Fix #61101: record that `_GLOBAL_OFFSET_TABLE_` is used in the IR symbol table. Note: The `PreservedSymbols` mechanism (https://reviews.llvm.org/D112595) that just sets `FB_used` is not applicable. The `getRuntimeLibcallSymbols` for extracting lazy runtime library symbols is for symbols that are "always" potentially used, but linkers don't have the code model information to make a precise decision. Pull Request: https://github.com/llvm/llvm-project/pull/89463
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