Bitcode streaming

include/llvm/Bitcode/BitcodeStream.h

Index: include/llvm/Bitcode/BitcodeStream.h
diff --git a/include/llvm/Bitcode/BitcodeStream.h b/include/llvm/Bitcode/BitcodeStream.h
new file mode 100644
index 0000000000000000000000000000000000000000..44311a5d19836d0c3016c6edf0ec998fa523ff91
--- /dev/null
+++ b/include/llvm/Bitcode/BitcodeStream.h
@@ -0,0 +1,42 @@
+//===---- llvm/Bitcode/BitcodeStream.h -  ----*- C++ -*-===//

[nlewycky, 2011/11/05 00:45:06]

Missing explanation of the file, also make it exactly 80 columns.

[(google.com) Derek Schuff, 2011/11/07 17:32:09]

OK. I'm a little unclear on exactly what is supposed to go at the very top here,
vs down below? is this just an ultra-short summary and a more detailed comment
below?
On 2011/11/05 00:45:06, nlewycky wrote:

+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Support for streaming (lazy reading) of bitcode files on disk

[nlewycky, 2011/11/05 00:45:06]

End with "."

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

Done.

+//
+//===----------------------------------------------------------------------===//
+
+
+#ifndef BITCODESTREAM_H_

[nlewycky, 2011/11/05 00:45:06]

Please use LLVM_BITCODE_BITCODESTREAM_H for similarity with neighbouring files.

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

Done.

+#define BITCODESTREAM_H_
+
+#include <stddef.h>

[nlewycky, 2011/11/05 00:45:06]

What do you need this for?

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

Originally had it for size_t. no longer necessary now that I have <string>
On 2011/11/05 00:45:06, nlewycky wrote:

+#include <string>
+
+namespace llvm {
+class MemoryBuffer;
+
+class BitcodeStreamer {
+public:
+  /// Fetch bytes [start-end) from the bitcode stream, and write them to the
+  /// buffer pointed to by buf. Returns the number of bytes actually written.
+  // TODO(dschuff): what's the right way to get useful error info?
+  //  string pointer out-arg? additional function to be called on short read?
+  virtual size_t GetBytes(unsigned char* buf, size_t len) = 0;
+  /// Returns true if the streamer owns its backing store (e.g. MemoryBuffer)

[nlewycky, 2011/11/05 00:45:06]

Newline to separate from above decl

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

Done.

+  virtual ~BitcodeStreamer() {}

[nlewycky, 2011/11/05 00:45:06]

Declare the virtual destructor here, but please it in a .cpp file. The current
code causes bloat in every .o file that #includes this header, because there is
no key function to base the vtable emission on.

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

Done.

+};
+
+BitcodeStreamer* getBitcodeFileStreamer(const std::string &Filename,
+                                        std::string *Err);
+
+BitcodeStreamer* getBitcodeMemoryStreamer(const char* Start, size_t Len);
+BitcodeStreamer* getBitcodeMemoryBufferStreamer(MemoryBuffer *Buf);

[nlewycky, 2011/11/05 00:45:06]

"BitcodeStreamer* " vs. "MemoryBuffer *". Please be consistent with where you
put the space (before or after the '*' or '&'). Most llvm code puts the space on
the left (ala. "MemoryBuffer *").

[(google.com) Derek Schuff, 2011/11/07 17:59:35]

OK. hopefully I got them all in this pass.
On 2011/11/05 00:45:06, nlewycky wrote:

+}
+
+#endif  // BITCODESTREAM_H_