Linker: Copy over function metadata attachments

[oota-llvm.git] / lib / Linker / LinkModules.cpp

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 21edc504080aef82a46a392ffe827777aee19402..34a353a6c82f37cb4ca83c11e90f0c71a68d99f8 100644 (file)
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -424,12 +424,17 @@ class ModuleLinker {
 
   DiagnosticHandlerFunction DiagnosticHandler;
 
+  /// For symbol clashes, prefer those from Src.
+  bool OverrideFromSrc;
+
 public:
   ModuleLinker(Module *dstM, Linker::IdentifiedStructTypeSet &Set, Module *srcM,
-               DiagnosticHandlerFunction DiagnosticHandler)
+               DiagnosticHandlerFunction DiagnosticHandler,
+               bool OverrideFromSrc)
       : DstM(dstM), SrcM(srcM), TypeMap(Set),
         ValMaterializer(TypeMap, DstM, LazilyLinkGlobalValues),
-        DiagnosticHandler(DiagnosticHandler) {}
+        DiagnosticHandler(DiagnosticHandler), OverrideFromSrc(OverrideFromSrc) {
+  }
 
   bool run();
 
@@ -725,6 +730,12 @@ bool ModuleLinker::getComdatResult(const Comdat *SrcC,
 bool ModuleLinker::shouldLinkFromSource(bool &LinkFromSrc,
                                         const GlobalValue &Dest,
                                         const GlobalValue &Src) {
+  // Should we unconditionally use the Src?
+  if (OverrideFromSrc) {
+    LinkFromSrc = true;
+    return false;
+  }
+
   // We always have to add Src if it has appending linkage.
   if (Src.hasAppendingLinkage()) {
     LinkFromSrc = true;
@@ -1071,8 +1082,9 @@ bool ModuleLinker::linkGlobalValueProto(GlobalValue *SGV) {
   } else {
     // If the GV is to be lazily linked, don't create it just yet.
     // The ValueMaterializerTy will deal with creating it if it's used.
-    if (!DGV && (SGV->hasLocalLinkage() || SGV->hasLinkOnceLinkage() ||
-                 SGV->hasAvailableExternallyLinkage())) {
+    if (!DGV && !OverrideFromSrc &&
+        (SGV->hasLocalLinkage() || SGV->hasLinkOnceLinkage() ||
+         SGV->hasAvailableExternallyLinkage())) {
       DoNotLinkFromSource.insert(SGV);
       return false;
     }
@@ -1193,6 +1205,13 @@ bool ModuleLinker::linkFunctionBody(Function &Dst, Function &Src) {
     ++DI;
   }
 
+  // Copy over the metadata attachments.
+  SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
+  Src.getAllMetadata(MDs);
+  for (const auto &I : MDs)
+    Dst.setMetadata(I.first, MapMetadata(I.second, ValueMap, RF_None, &TypeMap,
+                                         &ValMaterializer));
+
   // Splice the body of the source function into the dest function.
   Dst.getBasicBlockList().splice(Dst.end(), Src.getBasicBlockList());
 
@@ -1269,15 +1288,11 @@ void ModuleLinker::stripReplacedSubprograms() {
   if (!CompileUnits)
     return;
   for (unsigned I = 0, E = CompileUnits->getNumOperands(); I != E; ++I) {
-    DICompileUnit CU(CompileUnits->getOperand(I));
+    auto *CU = cast<MDCompileUnit>(CompileUnits->getOperand(I));
     assert(CU && "Expected valid compile unit");
 
-    DITypedArray<DISubprogram> SPs(CU.getSubprograms());
-    assert(SPs && "Expected valid subprogram array");
-
-    for (unsigned S = 0, SE = SPs.getNumElements(); S != SE; ++S) {
-      DISubprogram SP = SPs.getElement(S);
-      if (!SP || !SP.getFunction() || !Functions.count(SP.getFunction()))
+    for (MDSubprogram *SP : CU->getSubprograms()) {
+      if (!SP || !SP->getFunction() || !Functions.count(SP->getFunction()))
         continue;
 
       // Prevent DebugInfoFinder from tagging this as the canonical subprogram,
@@ -1742,9 +1757,9 @@ void Linker::deleteModule() {
   Composite = nullptr;
 }
 
-bool Linker::linkInModule(Module *Src) {
+bool Linker::linkInModule(Module *Src, bool OverrideSymbols) {
   ModuleLinker TheLinker(Composite, IdentifiedStructTypes, Src,
-                         DiagnosticHandler);
+                         DiagnosticHandler, OverrideSymbols);
   bool RetCode = TheLinker.run();
   Composite->dropTriviallyDeadConstantArrays();
   return RetCode;