From: Dan Gohman <gohman@apple.com>
Date: Tue, 22 Jun 2010 13:57:08 +0000 (+0000)
Subject: Add a comment explaining a non-obvious API.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=30f30e43861512d78023c84952e5e524c0003ae9;p=oota-llvm.git

Add a comment explaining a non-obvious API.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106539 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Support/MemoryBuffer.h b/include/llvm/Support/MemoryBuffer.h
index 38f61935d97..0b6cd12f6f4 100644
--- a/include/llvm/Support/MemoryBuffer.h
+++ b/include/llvm/Support/MemoryBuffer.h
@@ -26,6 +26,11 @@ namespace llvm {
 /// into a memory buffer.  In addition to basic access to the characters in the
 /// file, this interface guarantees you can read one character past the end of
 /// the file, and that this character will read as '\0'.
+///
+/// The '\0' guarantee is needed to support an optimization -- it's intended to
+/// be more efficient for clients which are reading all the data to stop
+/// reading when they encounter a '\0' than to continually check the file
+/// position to see if it has reached the end of the file.
 class MemoryBuffer {
   const char *BufferStart; // Start of the buffer.
   const char *BufferEnd;   // End of the buffer.