Fix abbreviation handling in munged bitcode writer.

include/llvm/Bitcode/NaCl/NaClBitstreamWriter.h

 //===- NaClBitstreamWriter.h - NaCl bitstream writer ------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This header defines the BitstreamWriter class.  This class can be used to
@@ skipping 403 matching lines @@
         assert(RecordIdx < Vals.size() && "Invalid abbrev/record");
         EmitAbbreviatedField(Op, Vals[RecordIdx]);
         ++RecordIdx;
       }
     }
     assert(RecordIdx == Vals.size() && "Not all record operands emitted!");
   }
 
 public:
 
-  /// Returns true if the given abbreviation index corresponds to a user-defined
-  /// abbreviation.
-  bool isUserRecordAbbreviation(unsigned Abbrev) const {
-    return Abbrev >= naclbitc::FIRST_APPLICATION_ABBREV
-        && Abbrev < (CurAbbrevs.size() + naclbitc::FIRST_APPLICATION_ABBREV);
+  /// Returns a pointer to the abbreviation currently associated with
+  // the abbreviation index. Returns nullptr if no such abbreviation

[jvoung (off chromium), 2015/05/20 22:40:09]

slash consistency /// vs //

period

[Karl, 2015/05/21 18:22:07]

Done.

+  const NaClBitCodeAbbrev *getAbbreviation(unsigned Index) const {
+    if (Index < naclbitc::FIRST_APPLICATION_ABBREV)
+      return nullptr;
+    unsigned AbbrevNo = Index - naclbitc::FIRST_APPLICATION_ABBREV;
+    if (AbbrevNo >= CurAbbrevs.size())
+      return nullptr;
+    return CurAbbrevs[AbbrevNo];
+  }
+
+  size_t getCurNumAbbreviations() const {

[jvoung (off chromium), 2015/05/20 22:40:09]

unused method ?

[Karl, 2015/05/21 18:22:07]

Removed.

+    return CurAbbrevs.size();
   }
 
   /// EmitRecord - Emit the specified record to the stream, using an abbrev if
   /// we have one to compress the output.
   template<typename uintty>
   void EmitRecord(unsigned Code, const SmallVectorImpl<uintty> &Vals,
                   unsigned Abbrev = 0) {
     if (!Abbrev) {
       // If we don't have an abbrev to use, emit this in its fully unabbreviated
       // form.
@@ skipping 92 matching lines @@
     Info.Abbrevs.push_back(Abbv);
 
     return Info.Abbrevs.size()-1+naclbitc::FIRST_APPLICATION_ABBREV;
   }
 };
 
 
 } // End llvm namespace
 
 #endif