Introduce a new BufferResult class to act as the return type of

SourceManager's getBuffer() (and similar) operations. This abstract
can be used to force callers to cope with errors in getBuffer(), such
as missing files and changed files. Fix a bunch of callers to use the
new interface.

Add some very basic checks for file consistency (file size,
modification time) into ContentCache::getBuffer(), although these
checks don't help much until we've updated the main callers (e.g.,
SourceManager::getSpelling()).

llvm-svn: 98585

1 files changed, 3 insertions, 3 deletions

diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 0b26ccbecba..4fba7b7bee1 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -80,9 +80,9 @@ bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir,
   }
   
   // Get the MemoryBuffer for this FID, if it fails, we fail.
-  const llvm::MemoryBuffer *InputFile =
-    getSourceManager().getBuffer(FID, &ErrorStr);
-  if (!ErrorStr.empty())
+  const llvm::MemoryBuffer *InputFile
+    = getSourceManager().getBuffer(FID).getBuffer(getDiagnostics());
+  if (!InputFile)
     return true;
   
   EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);