[all-commits] [llvm/llvm-project] 143133: [LLD] [COFF] Don't preserve unnecessary __imp_ pre...

[Martin Storsjö via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 143133fe685bd0b8819a96bdc1af6a4ff2877b13
      https://github.com/llvm/llvm-project/commit/143133fe685bd0b8819a96bdc1af6a4ff2877b13
  Author: Martin Storsjö <martin at martin.st>
  Date:   2023-12-04 (Mon, 04 Dec 2023)

  Changed paths:
    M lld/COFF/InputFiles.cpp
    M lld/test/COFF/lto-imp-prefix.ll

  Log Message:
  -----------
  [LLD] [COFF] Don't preserve unnecessary __imp_ prefixed symbols (#72989)

This redoes the fix from 3ab6209a3f93bdbeec8e9b9fcc00a9a4980915ff
differently, without the unwanted effect of preserving unnecessary
`__imp_` prefixed symbols.

If the referencing object is a regular object, the `__imp_` symbol will
have `isUsedInRegularObj` set on it from that already. If the
referencing object is an LTO object, we set `isUsedInRegularObj` for any
symbol starting with `__imp_`.

If the object file defining the `__imp_` symbol is a regular object, the
`isUsedInRegularObj` flag has no effect. If it is an LTO object, it
causes the symbol to be preserved.