Commit Graph

2 Commits

Author SHA1 Message Date
Teresa Johnson 290a839891 [LTO] Record whether LTOUnit splitting is enabled in index
Summary:
Records in the module summary index whether the bitcode was compiled
with the option necessary to enable splitting the LTO unit
(e.g. -fsanitize=cfi, -fwhole-program-vtables, or -fsplit-lto-unit).

The information is passed down to the ModuleSummaryIndex builder via a
new module flag "EnableSplitLTOUnit", which is propagated onto a flag
on the summary index.

This is then used during the LTO link to check whether all linked
summaries were built with the same value of this flag. If not, an error
is issued when we detect a situation requiring whole program visibility
of the class hierarchy. This is the case when both of the following
conditions are met:
1) We are performing LowerTypeTests or Whole Program Devirtualization.
2) There are type tests or type checked loads in the code.

Note I have also changed the ThinLTOBitcodeWriter to also gate the
module splitting on the value of this flag.

Reviewers: pcc

Subscribers: ormris, mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, dang, llvm-commits

Differential Revision: https://reviews.llvm.org/D53890

llvm-svn: 350948
2019-01-11 18:31:57 +00:00
Teresa Johnson 28023dbed7 [ThinLTO] Enable ThinLTO WholeProgramDevirt and LowerTypeTests in new PM
Summary:
Enable these passes for CFI and WPD in ThinLTO and LTO with the new pass
manager. Add a couple of tests for both PMs based on the clang tests
tools/clang/test/CodeGen/thinlto-distributed-cfi*.ll, but just test
through llvm-lto2 and not with distributed ThinLTO.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49429

llvm-svn: 337461
2018-07-19 14:51:32 +00:00