Change EmitRecordWithAbbrevImpl to take Optional record code. NFC.
[oota-llvm.git] / include / llvm / Bitcode / BitstreamWriter.h
index 1021fbd0dcdaf21f996c85a57197c10c8cad2d92..648a06e202e2e3ff44d70da19e908e8995fccd70 100644 (file)
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef BITSTREAM_WRITER_H
-#define BITSTREAM_WRITER_H
+#ifndef LLVM_BITCODE_BITSTREAMWRITER_H
+#define LLVM_BITCODE_BITSTREAMWRITER_H
 
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Bitcode/BitCodes.h"
+#include "llvm/Support/Endian.h"
 #include <vector>
 
 namespace llvm {
@@ -40,12 +42,12 @@ class BitstreamWriter {
   unsigned BlockInfoCurBID;
 
   /// CurAbbrevs - Abbrevs installed at in this block.
-  std::vector<BitCodeAbbrev*> CurAbbrevs;
+  std::vector<IntrusiveRefCntPtr<BitCodeAbbrev>> CurAbbrevs;
 
   struct Block {
     unsigned PrevCodeSize;
     unsigned StartSizeWord;
-    std::vector<BitCodeAbbrev*> PrevAbbrevs;
+    std::vector<IntrusiveRefCntPtr<BitCodeAbbrev>> PrevAbbrevs;
     Block(unsigned PCS, unsigned SSW) : PrevCodeSize(PCS), StartSizeWord(SSW) {}
   };
 
@@ -56,17 +58,14 @@ class BitstreamWriter {
   /// These describe abbreviations that all blocks of the specified ID inherit.
   struct BlockInfo {
     unsigned BlockID;
-    std::vector<BitCodeAbbrev*> Abbrevs;
+    std::vector<IntrusiveRefCntPtr<BitCodeAbbrev>> Abbrevs;
   };
   std::vector<BlockInfo> BlockInfoRecords;
 
   // BackpatchWord - Backpatch a 32-bit word in the output with the specified
   // value.
   void BackpatchWord(unsigned ByteNo, unsigned NewWord) {
-    Out[ByteNo++] = (unsigned char)(NewWord >>  0);
-    Out[ByteNo++] = (unsigned char)(NewWord >>  8);
-    Out[ByteNo++] = (unsigned char)(NewWord >> 16);
-    Out[ByteNo  ] = (unsigned char)(NewWord >> 24);
+    support::endian::write32le(&Out[ByteNo], NewWord);
   }
 
   void WriteByte(unsigned char Value) {
@@ -74,12 +73,9 @@ class BitstreamWriter {
   }
 
   void WriteWord(unsigned Value) {
-    unsigned char Bytes[4] = {
-      (unsigned char)(Value >>  0),
-      (unsigned char)(Value >>  8),
-      (unsigned char)(Value >> 16),
-      (unsigned char)(Value >> 24) };
-    Out.append(&Bytes[0], &Bytes[4]);
+    Value = support::endian::byte_swap<uint32_t, support::little>(Value);
+    Out.append(reinterpret_cast<const char *>(&Value),
+               reinterpret_cast<const char *>(&Value + 1));
   }
 
   unsigned GetBufferOffset() const {
@@ -97,18 +93,8 @@ public:
     : Out(O), CurBit(0), CurValue(0), CurCodeSize(2) {}
 
   ~BitstreamWriter() {
-    assert(CurBit == 0 && "Unflused data remaining");
+    assert(CurBit == 0 && "Unflushed data remaining");
     assert(BlockScope.empty() && CurAbbrevs.empty() && "Block imbalance");
-
-    // Free the BlockInfoRecords.
-    while (!BlockInfoRecords.empty()) {
-      BlockInfo &Info = BlockInfoRecords.back();
-      // Free blockinfo abbrev info.
-      for (unsigned i = 0, e = static_cast<unsigned>(Info.Abbrevs.size());
-           i != e; ++i)
-        Info.Abbrevs[i]->dropRef();
-      BlockInfoRecords.pop_back();
-    }
   }
 
   /// \brief Retrieve the current position in the stream, in bits.
@@ -204,7 +190,7 @@ public:
          i != e; ++i)
       if (BlockInfoRecords[i].BlockID == BlockID)
         return &BlockInfoRecords[i];
-    return 0;
+    return nullptr;
   }
 
   void EnterSubblock(unsigned BlockID, unsigned CodeLen) {
@@ -225,28 +211,19 @@ public:
 
     // Push the outer block's abbrev set onto the stack, start out with an
     // empty abbrev set.
-    BlockScope.push_back(Block(OldCodeSize, BlockSizeWordIndex));
+    BlockScope.emplace_back(OldCodeSize, BlockSizeWordIndex);
     BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
 
     // If there is a blockinfo for this BlockID, add all the predefined abbrevs
     // to the abbrev list.
     if (BlockInfo *Info = getBlockInfo(BlockID)) {
-      for (unsigned i = 0, e = static_cast<unsigned>(Info->Abbrevs.size());
-           i != e; ++i) {
-        CurAbbrevs.push_back(Info->Abbrevs[i]);
-        Info->Abbrevs[i]->addRef();
-      }
+      CurAbbrevs.insert(CurAbbrevs.end(), Info->Abbrevs.begin(),
+                        Info->Abbrevs.end());
     }
   }
 
   void ExitBlock() {
     assert(!BlockScope.empty() && "Block scope imbalance!");
-
-    // Delete all abbrevs.
-    for (unsigned i = 0, e = static_cast<unsigned>(CurAbbrevs.size());
-         i != e; ++i)
-      CurAbbrevs[i]->dropRef();
-
     const Block &B = BlockScope.back();
 
     // Block tail:
@@ -263,7 +240,7 @@ public:
 
     // Restore the inner block's code size and abbrev table.
     CurCodeSize = B.PrevCodeSize;
-    BlockScope.back().PrevAbbrevs.swap(CurAbbrevs);
+    CurAbbrevs = std::move(B.PrevAbbrevs);
     BlockScope.pop_back();
   }
 
@@ -309,21 +286,37 @@ private:
   /// EmitRecordWithAbbrevImpl - This is the core implementation of the record
   /// emission code.  If BlobData is non-null, then it specifies an array of
   /// data that should be emitted as part of the Blob or Array operand that is
-  /// known to exist at the end of the record.
+  /// known to exist at the end of the record. If Code is specified, then
+  /// it is the record code to emit before the Vals, which must not contain
+  /// the code.
   template<typename uintty>
   void EmitRecordWithAbbrevImpl(unsigned Abbrev, SmallVectorImpl<uintty> &Vals,
-                                StringRef Blob) {
+                                StringRef Blob, Optional<unsigned> Code) {
     const char *BlobData = Blob.data();
     unsigned BlobLen = (unsigned) Blob.size();
     unsigned AbbrevNo = Abbrev-bitc::FIRST_APPLICATION_ABBREV;
     assert(AbbrevNo < CurAbbrevs.size() && "Invalid abbrev #!");
-    BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo];
+    const BitCodeAbbrev *Abbv = CurAbbrevs[AbbrevNo].get();
 
     EmitCode(Abbrev);
 
+    unsigned i = 0, e = static_cast<unsigned>(Abbv->getNumOperandInfos());
+    if (Code) {
+      assert(e && "Expected non-empty abbreviation");
+      const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i++);
+
+      if (Op.isLiteral())
+        EmitAbbreviatedLiteral(Op, Code.getValue());
+      else {
+        assert(Op.getEncoding() != BitCodeAbbrevOp::Array &&
+               Op.getEncoding() != BitCodeAbbrevOp::Blob &&
+               "Expected literal or scalar");
+        EmitAbbreviatedField(Op, Code.getValue());
+      }
+    }
+
     unsigned RecordIdx = 0;
-    for (unsigned i = 0, e = static_cast<unsigned>(Abbv->getNumOperandInfos());
-         i != e; ++i) {
+    for (; i != e; ++i) {
       const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
       if (Op.isLiteral()) {
         assert(RecordIdx < Vals.size() && "Invalid abbrev/record");
@@ -331,7 +324,7 @@ private:
         ++RecordIdx;
       } else if (Op.getEncoding() == BitCodeAbbrevOp::Array) {
         // Array case.
-        assert(i+2 == e && "array op not second to last?");
+        assert(i + 2 == e && "array op not second to last?");
         const BitCodeAbbrevOp &EltEnc = Abbv->getOperandInfo(++i);
 
         // If this record has blob data, emit it, otherwise we must have record
@@ -347,7 +340,7 @@ private:
             EmitAbbreviatedField(EltEnc, (unsigned char)BlobData[i]);
 
           // Know that blob data is consumed for assertion below.
-          BlobData = 0;
+          BlobData = nullptr;
         } else {
           // Emit a vbr6 to indicate the number of elements present.
           EmitVBR(static_cast<uint32_t>(Vals.size()-RecordIdx), 6);
@@ -378,10 +371,11 @@ private:
             WriteByte((unsigned char)BlobData[i]);
 
           // Know that blob data is consumed for assertion below.
-          BlobData = 0;
+          BlobData = nullptr;
         } else {
           for (unsigned e = Vals.size(); RecordIdx != e; ++RecordIdx) {
-            assert(Vals[RecordIdx] < 256 && "Value too large to emit as blob");
+            assert(isUInt<8>(Vals[RecordIdx]) &&
+                   "Value too large to emit as blob");
             WriteByte((unsigned char)Vals[RecordIdx]);
           }
         }
@@ -396,7 +390,7 @@ private:
       }
     }
     assert(RecordIdx == Vals.size() && "Not all record operands emitted!");
-    assert(BlobData == 0 &&
+    assert(BlobData == nullptr &&
            "Blob data specified for record that doesn't use it!");
   }
 
@@ -418,10 +412,7 @@ public:
       return;
     }
 
-    // Insert the code into Vals to treat it uniformly.
-    Vals.insert(Vals.begin(), Code);
-
-    EmitRecordWithAbbrev(Abbrev, Vals);
+    EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef(), Code);
   }
 
   /// EmitRecordWithAbbrev - Emit a record with the specified abbreviation.
@@ -429,7 +420,7 @@ public:
   /// the first entry.
   template<typename uintty>
   void EmitRecordWithAbbrev(unsigned Abbrev, SmallVectorImpl<uintty> &Vals) {
-    EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef());
+    EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef(), None);
   }
 
   /// EmitRecordWithBlob - Emit the specified record to the stream, using an
@@ -440,12 +431,13 @@ public:
   template<typename uintty>
   void EmitRecordWithBlob(unsigned Abbrev, SmallVectorImpl<uintty> &Vals,
                           StringRef Blob) {
-    EmitRecordWithAbbrevImpl(Abbrev, Vals, Blob);
+    EmitRecordWithAbbrevImpl(Abbrev, Vals, Blob, None);
   }
   template<typename uintty>
   void EmitRecordWithBlob(unsigned Abbrev, SmallVectorImpl<uintty> &Vals,
                           const char *BlobData, unsigned BlobLen) {
-    return EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef(BlobData, BlobLen));
+    return EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef(BlobData, BlobLen),
+                                    None);
   }
 
   /// EmitRecordWithArray - Just like EmitRecordWithBlob, works with records
@@ -453,13 +445,13 @@ public:
   template<typename uintty>
   void EmitRecordWithArray(unsigned Abbrev, SmallVectorImpl<uintty> &Vals,
                           StringRef Array) {
-    EmitRecordWithAbbrevImpl(Abbrev, Vals, Array);
+    EmitRecordWithAbbrevImpl(Abbrev, Vals, Array, None);
   }
   template<typename uintty>
   void EmitRecordWithArray(unsigned Abbrev, SmallVectorImpl<uintty> &Vals,
                           const char *ArrayData, unsigned ArrayLen) {
-    return EmitRecordWithAbbrevImpl(Abbrev, Vals, StringRef(ArrayData, 
-                                                            ArrayLen));
+    return EmitRecordWithAbbrevImpl(Abbrev, Vals,
+                                    StringRef(ArrayData, ArrayLen), None);
   }
 
   //===--------------------------------------------------------------------===//
@@ -521,7 +513,7 @@ private:
       return *BI;
 
     // Otherwise, add a new record.
-    BlockInfoRecords.push_back(BlockInfo());
+    BlockInfoRecords.emplace_back();
     BlockInfoRecords.back().BlockID = BlockID;
     return BlockInfoRecords.back();
   }