tree 583ad2543f8c584885955cbaba501e249b18da1d
parent 2b1cc10450eefaa3a7223c13b03f4eb04dab2088
author Fangrui Song <maskray@google.com> 1539211737 +0000
committer Fangrui Song <maskray@google.com> 1539211737 +0000

[ELF] Don't warn on undefined symbols if UnresolvedPolicy::Ignore is used

Summary:
Add a condition UnresolvedPolicy::Ignore to elf::warnUnorderedSymbol to suppress Sym->isUndefined() warnings from both

1) --symbol-ordering-file=
2) .llvm.call-graph-profile

If --unresolved-symbols=ignore-all is used,

  no "undefined symbol" error/warning is emitted. It makes sense to not warn unorderable symbols.

Otherwise,

  If an executable is linked, the default policy UnresolvedPolicy::ErrorOrWarn will issue a "undefined symbol" error. The unorderable symbol warning is redundant.

  If a shared object is linked, it is possible that only part of object files are used and some symbols are left undefined. The warning is not very necessary.
    In particular for .llvm.call-graph-profile, when linking a shared object, a call graph profile may contain undefined symbols. This case generated a warning before but it will be suppressed by this patch.

Reviewers: ruiu, davidxl, espindola

Reviewed By: ruiu

Subscribers: grimar, emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D53044

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@344195 91177308-0d34-0410-b5e6-96231b3b80d8