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.

llvm-svn: 70157

3 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 8079acddb06..fe20f725878 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/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' ||
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.h b/llvm/lib/Bitcode/Reader/BitcodeReader.h
index 1fbf219fb8e..0dc470b24a2 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.h
+++ b/llvm/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;
   
diff --git a/llvm/lib/Bitcode/Reader/Deserialize.cpp b/llvm/lib/Bitcode/Reader/Deserialize.cpp
index 2014557a101..06da6ce7272 100644
--- a/llvm/lib/Bitcode/Reader/Deserialize.cpp
+++ b/llvm/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() {