commit 77c89b6958f51a0b26c4849d37a200c1bc0319df
author Peter Collingbourne <peter@pcc.me.uk> Tue Nov 08 04:17:11 2016 +0000
committer Peter Collingbourne <peter@pcc.me.uk> Tue Nov 08 04:17:11 2016 +0000
tree 7ac81d7f4f32b81635db74539ad07fdbd1a6c535
parent 939c7d916e1631cf2a005b4ba6c03726ecbe0f85

Bitcode: Decouple block info block state from reader.

As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106630.html

Move block info block state to a new class, BitstreamBlockInfo.
Clients may set the block info for a particular cursor with the
BitstreamCursor::setBlockInfo() method.

At this point BitstreamReader is not much more than a container for an
ArrayRef<uint8_t>, so remove it and replace all uses with direct uses
of memory buffers.

Differential Revision: https://reviews.llvm.org/D26259

llvm-svn: 286207

clang/lib/Serialization/ASTReader.cpp

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 650c46e..5c875ee 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -1711,7 +1711,7 @@
     BitstreamCursor &MacroCursor = I->MacroCursor;
 
     // If there was no preprocessor block, skip this file.
-    if (!MacroCursor.getBitStreamReader())
+    if (MacroCursor.getBitcodeBytes().empty())
       continue;
 
     BitstreamCursor Cursor = MacroCursor;
@@ -3798,7 +3798,7 @@
   return Success;
 }
 
-static ASTFileSignature readASTFileSignature(llvm::BitstreamReader &StreamFile);
+static ASTFileSignature readASTFileSignature(StringRef PCH);
 
 /// \brief Whether \p Stream starts with the AST/PCH file magic number 'CPCH'.
 static bool startsWithASTFileMagic(BitstreamCursor &Stream) {
@@ -3885,8 +3885,7 @@
 
   ModuleFile &F = *M;
   BitstreamCursor &Stream = F.Stream;
-  PCHContainerRdr.ExtractPCH(F.Buffer->getMemBufferRef(), F.StreamFile);
-  Stream.init(&F.StreamFile);
+  Stream = BitstreamCursor(PCHContainerRdr.ExtractPCH(*F.Buffer));
   F.SizeInBits = F.Buffer->getBufferSize() * 8;
   
   // Sniff for the signature.
@@ -4175,10 +4174,10 @@
   // Nothing to do for now.
 }
 
-/// \brief Reads and return the signature record from \p StreamFile's control
-/// block, or else returns 0.
-static ASTFileSignature readASTFileSignature(llvm::BitstreamReader &StreamFile){
-  BitstreamCursor Stream(StreamFile);
+/// \brief Reads and return the signature record from \p PCH's control block, or
+/// else returns 0.
+static ASTFileSignature readASTFileSignature(StringRef PCH) {
+  BitstreamCursor Stream(PCH);
   if (!startsWithASTFileMagic(Stream))
     return 0;
 
@@ -4216,9 +4215,7 @@
   }
 
   // Initialize the stream
-  llvm::BitstreamReader StreamFile;
-  PCHContainerRdr.ExtractPCH((*Buffer)->getMemBufferRef(), StreamFile);
-  BitstreamCursor Stream(StreamFile);
+  BitstreamCursor Stream(PCHContainerRdr.ExtractPCH(**Buffer));
 
   // Sniff for the signature.
   if (!startsWithASTFileMagic(Stream)) {
@@ -4318,9 +4315,7 @@
   }
 
   // Initialize the stream
-  llvm::BitstreamReader StreamFile;
-  PCHContainerRdr.ExtractPCH((*Buffer)->getMemBufferRef(), StreamFile);
-  BitstreamCursor Stream(StreamFile);
+  BitstreamCursor Stream(PCHContainerRdr.ExtractPCH(**Buffer));
 
   // Sniff for the signature.
   if (!startsWithASTFileMagic(Stream))

clang/lib/Serialization/GlobalModuleIndex.cpp

diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index e55ed40..9f986d5 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -245,11 +245,8 @@
     return std::make_pair(nullptr, EC_NotFound);
   std::unique_ptr<llvm::MemoryBuffer> Buffer = std::move(BufferOrErr.get());
 
-  /// \brief The bitstream reader from which we'll read the AST file.
-  llvm::BitstreamReader Reader(*Buffer);
-
   /// \brief The main bitstream cursor for the main block.
-  llvm::BitstreamCursor Cursor(Reader);
+  llvm::BitstreamCursor Cursor(*Buffer);
 
   // Sniff for the signature.
   if (Cursor.Read(8) != 'B' ||
@@ -503,9 +500,7 @@
   }
 
   // Initialize the input stream
-  llvm::BitstreamReader InStreamFile;
-  PCHContainerRdr.ExtractPCH((*Buffer)->getMemBufferRef(), InStreamFile);
-  llvm::BitstreamCursor InStream(InStreamFile);
+  llvm::BitstreamCursor InStream(PCHContainerRdr.ExtractPCH(**Buffer));
 
   // Sniff for the signature.
   if (InStream.Read(8) != 'C' ||

clang/lib/Serialization/ModuleManager.cpp

diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index 0a176f6..e50dcaa 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -135,15 +135,14 @@
     }
 
     // Initialize the stream.
-    PCHContainerRdr.ExtractPCH(ModuleEntry->Buffer->getMemBufferRef(),
-                               ModuleEntry->StreamFile);
+    ModuleEntry->Data = PCHContainerRdr.ExtractPCH(*ModuleEntry->Buffer);
   }
 
   if (ExpectedSignature) {
     // If we've not read the control block yet, read the signature eagerly now
     // so that we can check it.
     if (!ModuleEntry->Signature)
-      ModuleEntry->Signature = ReadSignature(ModuleEntry->StreamFile);
+      ModuleEntry->Signature = ReadSignature(ModuleEntry->Data);
 
     if (ModuleEntry->Signature != ExpectedSignature) {
       ErrorStr = ModuleEntry->Signature ? "signature mismatch"