[ThinLTO/WPD] Ensure devirtualized targets use promoted symbol when necessary

Summary:
This fixes a hole in the handling of devirtualized targets that were
local but need promoting due to devirtualization in another module. We
were not correctly referencing the promoted symbol in some cases. Make
sure the code that updates the name also looks at the ExportedGUIDs set
by utilizing a callback that checks all conditions (the callback
utilized by the internalization/promotion code).

Reviewers: pcc, davidxl, hiraditya

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68159

llvm-svn: 373485

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
index 4490a7ef62a..4055fe04999 100644
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -713,7 +713,7 @@ void runWholeProgramDevirtOnIndex(
 
 void updateIndexWPDForExports(
     ModuleSummaryIndex &Summary,
-    StringMap<FunctionImporter::ExportSetTy> &ExportLists,
+    function_ref<bool(StringRef, GlobalValue::GUID)> isExported,
     std::map<ValueInfo, std::vector<VTableSlotSummary>> &LocalWPDTargetsMap) {
   for (auto &T : LocalWPDTargetsMap) {
     auto &VI = T.first;
@@ -721,9 +721,7 @@ void updateIndexWPDForExports(
     assert(VI.getSummaryList().size() == 1 &&
            "Devirt of local target has more than one copy");
     auto &S = VI.getSummaryList()[0];
-    const auto &ExportList = ExportLists.find(S->modulePath());
-    if (ExportList == ExportLists.end() ||
-        !ExportList->second.count(VI.getGUID()))
+    if (!isExported(S->modulePath(), VI.getGUID()))
       continue;
 
     // It's been exported by a cross module import.