Read and write NamedMDNode.

llvm-svn: 77517

llvm/include/llvm/Bitcode/LLVMBitCodes.h

@@ -108,8 +108,10 @@ namespace bitc {
   };
 
   enum MetadataCodes {
-    METADATA_STRING  = 1,  // MDString:      [values]
-    METADATA_NODE    = 2   // MDNODE:        [n x (type num, value num)]
+    METADATA_STRING        = 1,   // MDSTRING:      [values]
+    METADATA_NODE          = 2,   // MDNODE:        [n x (type num, value num)]
+    METADATA_NAME          = 3,   // STRING:        [values]
+    METADATA_NAMED_NODE    = 4    // NAMEDMDNODE:   [n x mdnodes]
   };
   // The constants block (CONSTANTS_BLOCK_ID) describes emission for each
   // constant and maintains an implicit current type value.

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -734,6 +734,33 @@ bool BitcodeReader::ParseMetadata() {
     switch (Stream.ReadRecord(Code, Record)) {
     default:  // Default behavior: ignore.
       break;
+    case bitc::METADATA_NAME: {
+      // Read named of the named metadata.
+      unsigned NameLength = Record.size();
+      SmallString<8> Name;
+      Name.resize(NameLength);
+      for (unsigned i = 0; i != NameLength; ++i)
+        Name[i] = Record[i];
+      Record.clear();
+      Code = Stream.ReadCode();
+
+      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
+      if (Stream.ReadRecord(Code, Record) != bitc::METADATA_NAMED_NODE)
+        assert ( 0 && "Inavlid Named Metadata record");
+
+      // Read named metadata elements.
+      unsigned Size = Record.size();
+      SmallVector<MetadataBase*, 8> Elts;
+      for (unsigned i = 0; i != Size; ++i) {
+        Value *MD = ValueList.getValueFwdRef(Record[i], Type::MetadataTy);
+        if (MetadataBase *B = dyn_cast<MetadataBase>(MD))
+        Elts.push_back(B);
+      }
+      Value *V = NamedMDNode::Create(Name.c_str(), Elts.data(), Elts.size(), 
+                                     TheModule);
+      ValueList.AssignValue(V, NextValueNo++);
+      break;
+    }
     case bitc::METADATA_NODE: {
       if (Record.empty() || Record.size() % 2 == 1)
         return Error("Invalid METADATA_NODE record");

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -495,6 +495,7 @@ static void WriteModuleMetadata(const ValueEnumerator &VE,
   const ValueEnumerator::ValueList &Vals = VE.getValues();
   bool StartedMetadataBlock = false;
   unsigned MDSAbbrev = 0;
+  unsigned String8Abbrev = 0;
   SmallVector<uint64_t, 64> Record;
   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
     
@@ -525,6 +526,33 @@ static void WriteModuleMetadata(const ValueEnumerator &VE,
       // Emit the finished record.
       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
       Record.clear();
+    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
+      if (!StartedMetadataBlock)  {
+        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+        StartedMetadataBlock = true;
+        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+        Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+        String8Abbrev = Stream.EmitAbbrev(Abbv);
+      }
+
+      // Write name.
+      const char *StrBegin = NMD->getName().data();
+      for (unsigned i = 0, e = NMD->getName().size(); i != e; ++i)
+        Record.push_back(StrBegin[i]);
+      Stream.EmitRecord(bitc::METADATA_NAME, Record, String8Abbrev);
+      Record.clear();
+
+      // Write named metadata elements.
+      for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i) {
+        if (NMD->getElement(i)) 
+          Record.push_back(VE.getValueID(NMD->getElement(i)));
+        else 
+          Record.push_back(0);
+      }
+      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
+      Record.clear();
     }
   }
   
@@ -578,7 +606,7 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
   const Type *LastTy = 0;
   for (unsigned i = FirstVal; i != LastVal; ++i) {
     const Value *V = Vals[i].first;
-    if (isa<MDString>(V) || isa<MDNode>(V))
+    if (isa<MetadataBase>(V))
       continue;
     // If we need to switch types, do so now.
     if (V->getType() != LastTy) {

llvm/lib/Bitcode/Writer/ValueEnumerator.cpp

@@ -221,6 +221,18 @@ void ValueEnumerator::EnumerateValue(const Value *V) {
     return;
   }
 
+  if (const NamedMDNode *N = dyn_cast<NamedMDNode>(V)) {
+    Values.push_back(std::make_pair(V, 1U));
+    ValueMap[V] = Values.size();
+    ValueID = Values.size();
+    for(NamedMDNode::const_elem_iterator I = N->elem_begin(),
+          E = N->elem_end(); I != E; ++I) {
+      MetadataBase *M = *I;
+      EnumerateValue(M);
+    }
+    return;
+  }
+
   // Add the value.
   Values.push_back(std::make_pair(V, 1U));
   ValueID = Values.size();

llvm/test/Feature/NamedMDNode.ll

@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s | llvm-dis | grep "llvm.stuff = "
+
+;; Simple NamedMDNode
+!0 = metadata !{i32 42}
+!1 = metadata !{metadata !"foo"}
+!llvm.stuff = !{!0, !1}