IR: Return unique_ptr from MDNode::getTemporary()

Change `MDTuple::getTemporary()` and `MDLocation::getTemporary()` to
return (effectively) `std::unique_ptr<T, MDNode::deleteTemporary>`, and
clean up call sites.  (For now, `DIBuilder` call sites just call
`release()` immediately.)

There's an accompanying change in each of clang and polly to use the new
API.

llvm-svn: 226504

7 files changed, 27 insertions, 38 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index ce195381cfb..421a2bcbaba 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -531,13 +531,13 @@ bool LLParser::ParseMDNodeID(MDNode *&Result) {
   }
 
   // Otherwise, create MDNode forward reference.
-  MDTuple *FwdNode = MDTuple::getTemporary(Context, None);
-  ForwardRefMDNodes[MID] = std::make_pair(FwdNode, Lex.getLoc());
+  auto &FwdRef = ForwardRefMDNodes[MID];
+  FwdRef = std::make_pair(MDTuple::getTemporary(Context, None), Lex.getLoc());
 
   if (NumberedMetadata.size() <= MID)
     NumberedMetadata.resize(MID+1);
-  NumberedMetadata[MID].reset(FwdNode);
-  Result = FwdNode;
+  Result = FwdRef.first.get();
+  NumberedMetadata[MID].reset(Result);
   return false;
 }
 
@@ -597,9 +597,7 @@ bool LLParser::ParseStandaloneMetadata() {
   // See if this was forward referenced, if so, handle it.
   auto FI = ForwardRefMDNodes.find(MetadataID);
   if (FI != ForwardRefMDNodes.end()) {
-    MDTuple *Temp = FI->second.first;
-    Temp->replaceAllUsesWith(Init);
-    MDNode::deleteTemporary(Temp);
+    FI->second.first->replaceAllUsesWith(Init);
     ForwardRefMDNodes.erase(FI);
 
     assert(NumberedMetadata[MetadataID] == Init && "Tracking VH didn't work");
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index 54e0d5bf020..b1f94c237a9 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -136,7 +136,7 @@ namespace llvm {
     std::vector<std::pair<Type*, LocTy> > NumberedTypes;
 
     std::vector<TrackingMDNodeRef> NumberedMetadata;
-    std::map<unsigned, std::pair<MDTuple *, LocTy>> ForwardRefMDNodes;
+    std::map<unsigned, std::pair<TempMDTuple, LocTy>> ForwardRefMDNodes;
 
     // Global Value reference information.
     std::map<std::string, std::pair<GlobalValue*, LocTy> > ForwardRefVals;
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index a9adaf4febe..c158d356a16 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -541,9 +541,8 @@ void BitcodeReaderMDValueList::AssignValue(Metadata *MD, unsigned Idx) {
   }
 
   // If there was a forward reference to this value, replace it.
-  MDTuple *PrevMD = cast<MDTuple>(OldMD.get());
+  TempMDTuple PrevMD(cast<MDTuple>(OldMD.get()));
   PrevMD->replaceAllUsesWith(MD);
-  MDNode::deleteTemporary(PrevMD);
   --NumFwdRefs;
 }
 
@@ -557,7 +556,7 @@ Metadata *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
   // Create and return a placeholder, which will later be RAUW'd.
   AnyFwdRefs = true;
   ++NumFwdRefs;
-  Metadata *MD = MDNode::getTemporary(Context, None);
+  Metadata *MD = MDNode::getTemporary(Context, None).release();
   MDValuePtrs[Idx].reset(MD);
   return MD;
 }
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 2de109b86cf..fdc0b1bb97b 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -142,15 +142,15 @@ DICompileUnit DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
   assert(!Filename.empty() &&
          "Unable to create compile unit without filename");
   Metadata *TElts[] = {HeaderBuilder::get(DW_TAG_base_type).get(VMContext)};
-  TempEnumTypes = MDNode::getTemporary(VMContext, TElts);
+  TempEnumTypes = MDNode::getTemporary(VMContext, TElts).release();
 
-  TempRetainTypes = MDNode::getTemporary(VMContext, TElts);
+  TempRetainTypes = MDNode::getTemporary(VMContext, TElts).release();
 
-  TempSubprograms = MDNode::getTemporary(VMContext, TElts);
+  TempSubprograms = MDNode::getTemporary(VMContext, TElts).release();
 
-  TempGVs = MDNode::getTemporary(VMContext, TElts);
+  TempGVs = MDNode::getTemporary(VMContext, TElts).release();
 
-  TempImportedModules = MDNode::getTemporary(VMContext, TElts);
+  TempImportedModules = MDNode::getTemporary(VMContext, TElts).release();
 
   Metadata *Elts[] = {HeaderBuilder::get(dwarf::DW_TAG_compile_unit)
                           .concat(Lang)
@@ -825,7 +825,7 @@ DICompositeType DIBuilder::createReplaceableForwardDecl(
       nullptr, // TemplateParams
       UniqueIdentifier.empty() ? nullptr
                                : MDString::get(VMContext, UniqueIdentifier)};
-  DICompositeType RetTy(MDNode::getTemporary(VMContext, Elts));
+  DICompositeType RetTy(MDNode::getTemporary(VMContext, Elts).release());
   assert(RetTy.isCompositeType() &&
          "createReplaceableForwardDecl result should be a DIType");
   if (!UniqueIdentifier.empty())
@@ -903,7 +903,7 @@ DIGlobalVariable DIBuilder::createTempGlobalVariableFwdDecl(
   return createGlobalVariableHelper(VMContext, Context, Name, LinkageName, F,
                                     LineNumber, Ty, isLocalToUnit, Val, Decl,
                                     false, [&](ArrayRef<Metadata *> Elts) {
-    return MDNode::getTemporary(VMContext, Elts);
+    return MDNode::getTemporary(VMContext, Elts).release();
   });
 }
 
@@ -1007,7 +1007,7 @@ DISubprogram DIBuilder::createFunction(DIDescriptor Context, StringRef Name,
   return createFunctionHelper(VMContext, Context, Name, LinkageName, File,
                               LineNo, Ty, isLocalToUnit, isDefinition,
                               ScopeLine, Flags, isOptimized, Fn, TParams, Decl,
-                              MDNode::getTemporary(VMContext, None),
+                              MDNode::getTemporary(VMContext, None).release(),
                               [&](ArrayRef<Metadata *> Elts) -> MDNode *{
     MDNode *Node = MDNode::get(VMContext, Elts);
     // Create a named metadata so that we
@@ -1030,7 +1030,7 @@ DIBuilder::createTempFunctionFwdDecl(DIDescriptor Context, StringRef Name,
                               LineNo, Ty, isLocalToUnit, isDefinition,
                               ScopeLine, Flags, isOptimized, Fn, TParams, Decl,
                               nullptr, [&](ArrayRef<Metadata *> Elts) {
-    return MDNode::getTemporary(VMContext, Elts);
+    return MDNode::getTemporary(VMContext, Elts).release();
   });
 }
 
diff --git a/llvm/lib/IR/MDBuilder.cpp b/llvm/lib/IR/MDBuilder.cpp
index c7fcf7a2c34..d6d03b48d0f 100644
--- a/llvm/lib/IR/MDBuilder.cpp
+++ b/llvm/lib/IR/MDBuilder.cpp
@@ -68,9 +68,9 @@ MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
 
 MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
   // To ensure uniqueness the root node is self-referential.
-  MDNode *Dummy = MDNode::getTemporary(Context, None);
+  auto Dummy = MDNode::getTemporary(Context, None);
 
-  SmallVector<Metadata *, 3> Args(1, Dummy);
+  SmallVector<Metadata *, 3> Args(1, Dummy.get());
   if (Extra)
     Args.push_back(Extra);
   if (!Name.empty())
@@ -82,7 +82,7 @@ MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
   //   !1 = metadata !{metadata !0} <- root
   // Replace the dummy operand with the root node itself and delete the dummy.
   Root->replaceOperandWith(0, Root);
-  MDNode::deleteTemporary(Dummy);
+
   // We now have
   //   !1 = metadata !{metadata !1} <- self-referential root
   return Root;
diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index 3cebd232984..f14afdb78cb 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -319,13 +319,12 @@ static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) {
 
   // Now we have a complete set of all metadata in the chains used to specify
   // the noalias scopes and the lists of those scopes.
-  SmallVector<MDTuple *, 16> DummyNodes;
+  SmallVector<TempMDTuple, 16> DummyNodes;
   DenseMap<const MDNode *, TrackingMDNodeRef> MDMap;
   for (SetVector<const MDNode *>::iterator I = MD.begin(), IE = MD.end();
        I != IE; ++I) {
-    MDTuple *Dummy = MDTuple::getTemporary(CalledFunc->getContext(), None);
-    DummyNodes.push_back(Dummy);
-    MDMap[*I].reset(Dummy);
+    DummyNodes.push_back(MDTuple::getTemporary(CalledFunc->getContext(), None));
+    MDMap[*I].reset(DummyNodes.back().get());
   }
 
   // Create new metadata nodes to replace the dummy nodes, replacing old
@@ -389,10 +388,6 @@ static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) {
         NI->setMetadata(LLVMContext::MD_noalias, M);
     }
   }
-
-  // Now that everything has been replaced, delete the dummy nodes.
-  for (unsigned i = 0, ie = DummyNodes.size(); i != ie; ++i)
-    MDNode::deleteTemporary(DummyNodes[i]);
 }
 
 /// AddAliasScopeMetadata - If the inlined function has noalias arguments, then
diff --git a/llvm/lib/Transforms/Utils/ValueMapper.cpp b/llvm/lib/Transforms/Utils/ValueMapper.cpp
index b195c6349b7..528bf373fff 100644
--- a/llvm/lib/Transforms/Utils/ValueMapper.cpp
+++ b/llvm/lib/Transforms/Utils/ValueMapper.cpp
@@ -249,12 +249,11 @@ static Metadata *mapDistinctNode(const UniquableMDNode *Node,
 
   // In general we need a dummy node, since whether the operands are null can
   // affect the size of the node.
-  MDTuple *Dummy = MDTuple::getTemporary(Node->getContext(), None);
-  mapToMetadata(VM, Node, Dummy);
+  auto Dummy = MDTuple::getTemporary(Node->getContext(), None);
+  mapToMetadata(VM, Node, Dummy.get());
   Metadata *NewMD = cloneMDNode(Node, VM, Flags, TypeMapper, Materializer,
                                 /* IsDistinct */ true);
   Dummy->replaceAllUsesWith(NewMD);
-  MDNode::deleteTemporary(Dummy);
   return mapToMetadata(VM, Node, NewMD);
 }
 
@@ -285,14 +284,13 @@ static Metadata *mapUniquedNode(const UniquableMDNode *Node,
   assert(Node->isUniqued() && "Expected uniqued node");
 
   // Create a dummy node in case we have a metadata cycle.
-  MDTuple *Dummy = MDTuple::getTemporary(Node->getContext(), None);
-  mapToMetadata(VM, Node, Dummy);
+  auto Dummy = MDTuple::getTemporary(Node->getContext(), None);
+  mapToMetadata(VM, Node, Dummy.get());
 
   // Check all operands to see if any need to be remapped.
   if (!shouldRemapUniquedNode(Node, VM, Flags, TypeMapper, Materializer)) {
     // Use an identity mapping.
     mapToSelf(VM, Node);
-    MDNode::deleteTemporary(Dummy);
     return const_cast<Metadata *>(static_cast<const Metadata *>(Node));
   }
 
@@ -300,7 +298,6 @@ static Metadata *mapUniquedNode(const UniquableMDNode *Node,
   Metadata *NewMD = cloneMDNode(Node, VM, Flags, TypeMapper, Materializer,
                                 /* IsDistinct */ false);
   Dummy->replaceAllUsesWith(NewMD);
-  MDNode::deleteTemporary(Dummy);
   return mapToMetadata(VM, Node, NewMD);
 }