Import LLVM 8.0.0 release including clang, lld and lldb.

1 files changed, 60 insertions, 9 deletions

diff --git a/gnu/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp b/gnu/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
index 479816a339d..81d63ee8039 100644
--- a/gnu/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
+++ b/gnu/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
@@ -124,7 +124,6 @@ FunctionImportGlobalProcessing::getLinkage(const GlobalValue *SGV,
     return SGV->getLinkage();
 
   switch (SGV->getLinkage()) {
-  case GlobalValue::LinkOnceAnyLinkage:
   case GlobalValue::LinkOnceODRLinkage:
   case GlobalValue::ExternalLinkage:
     // External and linkonce definitions are converted to available_externally
@@ -144,11 +143,13 @@ FunctionImportGlobalProcessing::getLinkage(const GlobalValue *SGV,
     // An imported available_externally declaration stays that way.
     return SGV->getLinkage();
 
+  case GlobalValue::LinkOnceAnyLinkage:
   case GlobalValue::WeakAnyLinkage:
-    // Can't import weak_any definitions correctly, or we might change the
-    // program semantics, since the linker will pick the first weak_any
-    // definition and importing would change the order they are seen by the
-    // linker. The module linking caller needs to enforce this.
+    // Can't import linkonce_any/weak_any definitions correctly, or we might
+    // change the program semantics, since the linker will pick the first
+    // linkonce_any/weak_any definition and importing would change the order
+    // they are seen by the linker. The module linking caller needs to enforce
+    // this.
     assert(!doImportAsDefinition(SGV));
     // If imported as a declaration, it becomes external_weak.
     return SGV->getLinkage();
@@ -202,10 +203,26 @@ FunctionImportGlobalProcessing::getLinkage(const GlobalValue *SGV,
 
 void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) {
 
-  // Check the summaries to see if the symbol gets resolved to a known local
-  // definition.
+  ValueInfo VI;
   if (GV.hasName()) {
-    ValueInfo VI = ImportIndex.getValueInfo(GV.getGUID());
+    VI = ImportIndex.getValueInfo(GV.getGUID());
+    // Set synthetic function entry counts.
+    if (VI && ImportIndex.hasSyntheticEntryCounts()) {
+      if (Function *F = dyn_cast<Function>(&GV)) {
+        if (!F->isDeclaration()) {
+          for (auto &S : VI.getSummaryList()) {
+            FunctionSummary *FS = dyn_cast<FunctionSummary>(S->getBaseObject());
+            if (FS->modulePath() == M.getModuleIdentifier()) {
+              F->setEntryCount(Function::ProfileCount(FS->entryCount(),
+                                                      Function::PCT_Synthetic));
+              break;
+            }
+          }
+        }
+      }
+    }
+    // Check the summaries to see if the symbol gets resolved to a known local
+    // definition.
     if (VI && VI.isDSOLocal()) {
       GV.setDSOLocal(true);
       if (GV.hasDLLImportStorageClass())
@@ -213,9 +230,27 @@ void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) {
     }
   }
 
+  // Mark read-only variables which can be imported with specific attribute.
+  // We can't internalize them now because IRMover will fail to link variable
+  // definitions to their external declarations during ThinLTO import. We'll
+  // internalize read-only variables later, after import is finished.
+  // See internalizeImmutableGVs.
+  //
+  // If global value dead stripping is not enabled in summary then
+  // propagateConstants hasn't been run. We can't internalize GV
+  // in such case.
+  if (!GV.isDeclaration() && VI && ImportIndex.withGlobalValueDeadStripping()) {
+    const auto &SL = VI.getSummaryList();
+    auto *GVS = SL.empty() ? nullptr : dyn_cast<GlobalVarSummary>(SL[0].get());
+    if (GVS && GVS->isReadOnly())
+      cast<GlobalVariable>(&GV)->addAttribute("thinlto-internalize");
+  }
+
   bool DoPromote = false;
   if (GV.hasLocalLinkage() &&
       ((DoPromote = shouldPromoteLocalToGlobal(&GV)) || isPerformingImport())) {
+    // Save the original name string before we rename GV below.
+    auto Name = GV.getName().str();
     // Once we change the name or linkage it is difficult to determine
     // again whether we should promote since shouldPromoteLocalToGlobal needs
     // to locate the summary (based on GUID from name and linkage). Therefore,
@@ -224,13 +259,19 @@ void FunctionImportGlobalProcessing::processGlobalForThinLTO(GlobalValue &GV) {
     GV.setLinkage(getLinkage(&GV, DoPromote));
     if (!GV.hasLocalLinkage())
       GV.setVisibility(GlobalValue::HiddenVisibility);
+
+    // If we are renaming a COMDAT leader, ensure that we record the COMDAT
+    // for later renaming as well. This is required for COFF.
+    if (const auto *C = GV.getComdat())
+      if (C->getName() == Name)
+        RenamedComdats.try_emplace(C, M.getOrInsertComdat(GV.getName()));
   } else
     GV.setLinkage(getLinkage(&GV, /* DoPromote */ false));
 
   // Remove functions imported as available externally defs from comdats,
   // as this is a declaration for the linker, and will be dropped eventually.
   // It is illegal for comdats to contain declarations.
-  auto *GO = dyn_cast_or_null<GlobalObject>(&GV);
+  auto *GO = dyn_cast<GlobalObject>(&GV);
   if (GO && GO->isDeclarationForLinker() && GO->hasComdat()) {
     // The IRMover should not have placed any imported declarations in
     // a comdat, so the only declaration that should be in a comdat
@@ -248,6 +289,16 @@ void FunctionImportGlobalProcessing::processGlobalsForThinLTO() {
     processGlobalForThinLTO(SF);
   for (GlobalAlias &GA : M.aliases())
     processGlobalForThinLTO(GA);
+
+  // Replace any COMDATS that required renaming (because the COMDAT leader was
+  // promoted and renamed).
+  if (!RenamedComdats.empty())
+    for (auto &GO : M.global_objects())
+      if (auto *C = GO.getComdat()) {
+        auto Replacement = RenamedComdats.find(C);
+        if (Replacement != RenamedComdats.end())
+          GO.setComdat(Replacement->second);
+      }
 }
 
 bool FunctionImportGlobalProcessing::run() {