Bitcode streaming

include/llvm/Support/IRReader.h

 //===---- llvm/Support/IRReader.h - Reader for LLVM IR files ----*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines functions for reading LLVM IR. They support both
 // Bitcode and Assembly, automatically detecting the input format.
 //
 // These functions must be defined in a header file in order to avoid
 // library dependencies, since they reference both Bitcode and Assembly
 // functions.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_SUPPORT_IRREADER_H
 #define LLVM_SUPPORT_IRREADER_H
 
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Assembly/Parser.h"
+#include "llvm/Bitcode/BitcodeStream.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/system_error.h"
 
 namespace llvm {
 
   /// If the given MemoryBuffer holds a bitcode image, return a Module for it
   /// which does lazy deserialization of function bodies.  Otherwise, attempt to
   /// parse it as LLVM Assembly and return a fully populated Module. This
@@ skipping 28 matching lines @@
     OwningPtr<MemoryBuffer> File;
     if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
       Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
                          "Could not open input file: " + ec.message());
       return 0;
     }
 
     return getLazyIRModule(File.take(), Err, Context);
   }
 
+  // like lazy file module but does not read the whole file at the start;

[jasonwkim, 2011/10/25 21:34:12]

Use /// for doxygen

[(google.com) Derek Schuff, 2011/10/25 22:23:22]

Done.

+  // instead executes a callback to get more bytes as needed by the parser.
+  // The stream must contain bitcode.
+  inline Module *getLazyIRStreamModule(const std::string &Filename,
+                                       SMDiagnostic &Err,
+                                       LLVMContext &Context,
+                                       StreamChunkCallback cb) {
+    std::string ErrMsg;
+    Module *M = getLazyBitcodeStreamModule(Filename, cb, Context, &ErrMsg);
+    if (M == 0) {
+      Err = SMDiagnostic(Filename, SourceMgr::DK_Error, ErrMsg);
+      return 0;
+    }
+    return M;
+  }
+
   /// If the given MemoryBuffer holds a bitcode image, return a Module
   /// for it.  Otherwise, attempt to parse it as LLVM Assembly and return
   /// a Module for it. This function *always* takes ownership of the given
   /// MemoryBuffer.
   inline Module *ParseIR(MemoryBuffer *Buffer,
                          SMDiagnostic &Err,
                          LLVMContext &Context) {
     if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
                   (const unsigned char *)Buffer->getBufferEnd())) {
       std::string ErrMsg;
@@ skipping 21 matching lines @@
                          "Could not open input file: " + ec.message());
       return 0;
     }
 
     return ParseIR(File.take(), Err, Context);
   }
 
 }
 
 #endif