Commit Graph

2 Commits

Author SHA1 Message Date
Steven Wu 05a358cdcd [ThinLTO] Fix ThinLTOCodegenerator to export llvm.used symbols
Summary:
Reapply r357931 with fixes to ThinLTO testcases and llvm-lto tool.

ThinLTOCodeGenerator currently does not preserve llvm.used symbols and
it can internalize them. In order to pass the necessary information to the
legacy ThinLTOCodeGenerator, the input to the code generator is
rewritten to be based on lto::InputFile.

Now ThinLTO using the legacy LTO API will requires data layout in
Module.

"internalize" thinlto action in llvm-lto is updated to run both
"promote" and "internalize" with the same configuration as
ThinLTOCodeGenerator. The old "promote" + "internalize" option does not
produce the same output as ThinLTOCodeGenerator.

This fixes: PR41236
rdar://problem/49293439

Reviewers: tejohnson, pcc, kromanova, dexonsmith

Reviewed By: tejohnson

Subscribers: ormris, bd1976llvm, mehdi_amini, inglorion, eraman, hiraditya, jkorous, dexonsmith, arphaman, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60421

llvm-svn: 358601
2019-04-17 17:38:09 +00:00
Steven Wu 33ba93c2b5 [ThinLTO] Teach ThinLTO about auto hide symbols
Summary:
For symbols that has linkonce_odr linkage and unnamed_addr, it can be
auto hide by linker to avoid weak external symbols. Teach ThinLTO to
perform auto hide so it can safely promote linkonce_odr to weak symbols
without breaking this nice property.

Reviewers: tejohnson, mehdi_amini

Reviewed By: tejohnson

Subscribers: inglorion, eraman, rnk, pcc, llvm-commits

Differential Revision: https://reviews.llvm.org/D43130

llvm-svn: 324757
2018-02-09 18:34:08 +00:00