Unbreak and add test case for r90276, a situation in which getBuffer is expected to fail.

Also, update SourceManager.h doxyments for getBuffer() to reflect reality.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90701 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 6 deletions

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index 3b170a6a74..b4cf959dc5 100644
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -70,8 +70,8 @@ namespace SrcMgr {
     unsigned NumLines;
 
     /// getBuffer - Returns the memory buffer for the associated content.  If
-    /// there is an error opening this buffer the first time, this returns null
-    /// and fills in the ErrorStr with a reason.
+    /// there is an error opening this buffer the first time, this manufactures
+    /// a temporary buffer and returns a non-empty error string.
     const llvm::MemoryBuffer *getBuffer(std::string *ErrorStr = 0) const;
 
     /// getSize - Returns the size of the content encapsulated by this
@@ -426,10 +426,9 @@ public:
   // FileID manipulation methods.
   //===--------------------------------------------------------------------===//
 
-  /// getBuffer - Return the buffer for the specified FileID.  If there is an
-  /// error opening this buffer the first time, this returns null and fills in
-  /// the ErrorStr with a reason.
-  ///
+  /// getBuffer - Return the buffer for the specified FileID. If there is an
+  /// error opening this buffer the first time, this manufactures a temporary
+  /// buffer and returns a non-empty error string.
   const llvm::MemoryBuffer *getBuffer(FileID FID, std::string *Error = 0) const{
     return getSLocEntry(FID).getFile().getContentCache()->getBuffer(Error);
   }