Change BitstreamCursor::skipRecord to return the record code (NFC)

llvm-svn: 291026

2 files changed, 16 insertions, 6 deletions

diff --git a/llvm/include/llvm/Bitcode/BitstreamReader.h b/llvm/include/llvm/Bitcode/BitstreamReader.h
index 3118a2fd6d9..fc06eeefbf2 100644
--- a/llvm/include/llvm/Bitcode/BitstreamReader.h
+++ b/llvm/include/llvm/Bitcode/BitstreamReader.h
@@ -477,8 +477,8 @@ public:
     return CurAbbrevs[AbbrevNo].get();
   }
 
-  /// Read the current record and discard it.
-  void skipRecord(unsigned AbbrevID);
+  /// Read the current record and discard it, returning the code for the record.
+  unsigned skipRecord(unsigned AbbrevID);
 
   unsigned readRecord(unsigned AbbrevID, SmallVectorImpl<uint64_t> &Vals,
                       StringRef *Blob = nullptr);
diff --git a/llvm/lib/Bitcode/Reader/BitstreamReader.cpp b/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
index 0c45b4b4cde..771cf3d927b 100644
--- a/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
@@ -93,20 +93,29 @@ static void skipAbbreviatedField(BitstreamCursor &Cursor,
 }
 
 /// skipRecord - Read the current record and discard it.
-void BitstreamCursor::skipRecord(unsigned AbbrevID) {
+unsigned BitstreamCursor::skipRecord(unsigned AbbrevID) {
   // Skip unabbreviated records by reading past their entries.
   if (AbbrevID == bitc::UNABBREV_RECORD) {
     unsigned Code = ReadVBR(6);
-    (void)Code;
     unsigned NumElts = ReadVBR(6);
     for (unsigned i = 0; i != NumElts; ++i)
       (void)ReadVBR64(6);
-    return;
+    return Code;
   }
 
   const BitCodeAbbrev *Abbv = getAbbrev(AbbrevID);
+  const BitCodeAbbrevOp &CodeOp = Abbv->getOperandInfo(0);
+  unsigned Code;
+  if (CodeOp.isLiteral())
+    Code = CodeOp.getLiteralValue();
+  else {
+    if (CodeOp.getEncoding() == BitCodeAbbrevOp::Array ||
+        CodeOp.getEncoding() == BitCodeAbbrevOp::Blob)
+      report_fatal_error("Abbreviation starts with an Array or a Blob");
+    Code = readAbbreviatedField(*this, CodeOp);
+  }
 
-  for (unsigned i = 0, e = Abbv->getNumOperandInfos(); i != e; ++i) {
+  for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i < e; ++i) {
     const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
     if (Op.isLiteral())
       continue;
@@ -164,6 +173,7 @@ void BitstreamCursor::skipRecord(unsigned AbbrevID) {
     // Skip over the blob.
     JumpToBit(NewEnd);
   }
+  return Code;
 }
 
 unsigned BitstreamCursor::readRecord(unsigned AbbrevID,