Make a major API change to BitstreamReader: split all the reading

state out of the BitstreamReader class into a BitstreamCursor class.
Doing this allows the client to have multiple cursors into the same
file, each with potentially different live block stacks and
abbreviation records.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70157 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -1346,7 +1346,8 @@ bool BitcodeReader::ParseBitcode() {
     if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
       return Error("Invalid bitcode wrapper header");
   
-  Stream.init(BufPtr, BufEnd);
+  StreamFile.init(BufPtr, BufEnd);
+  Stream.init(StreamFile);
   
   // Sniff for the signature.
   if (Stream.Read(8) != 'B' ||

lib/Bitcode/Reader/BitcodeReader.h

@@ -86,7 +86,8 @@ public:
 
 class BitcodeReader : public ModuleProvider {
   MemoryBuffer *Buffer;
-  BitstreamReader Stream;
+  BitstreamReader StreamFile;
+  BitstreamCursor Stream;
   
   const char *ErrorString;
   

lib/Bitcode/Reader/Deserialize.cpp

@@ -22,7 +22,7 @@ using namespace llvm;
 Deserializer::Deserializer(BitstreamReader& stream)
   : Stream(stream), RecIdx(0), FreeList(NULL), AbbrevNo(0), RecordCode(0) {
 
-    StreamStart = Stream.GetCurrentBitNo();
+  StreamStart = Stream.GetCurrentBitNo();
 }
 
 Deserializer::~Deserializer() {