Have SourceManager::getLocForEndOfFile() point at the "EOF" location of the FileID.

This fixes a crash due to SourceManager::getLocForEndOfFile() returning an off-by-one location
when the the FileID is for an empty file.

rdar://13803893

llvm-svn: 181285

clang/include/clang/Basic/SourceManager.h

@@ -1005,7 +1005,7 @@ public:
       return SourceLocation();
     
     unsigned FileOffset = Entry.getOffset();
-    return SourceLocation::getFileLoc(FileOffset + getFileIDSize(FID) - 1);
+    return SourceLocation::getFileLoc(FileOffset + getFileIDSize(FID));
   }
 
   /// \brief Returns the include location if \p FID is a \#include'd file

clang/lib/Rewrite/Frontend/InclusionRewriter.cpp

@@ -464,7 +464,7 @@ bool InclusionRewriter::Process(FileID FileId,
     RawLex.LexFromRawLexer(RawToken);
   }
   OutputContentUpTo(FromFile, NextToWrite,
-    SM.getFileOffset(SM.getLocForEndOfFile(FileId)) + 1, EOL, Line,
+    SM.getFileOffset(SM.getLocForEndOfFile(FileId)), EOL, Line,
     /*EnsureNewline*/true);
   return true;
 }

clang/test/Index/file-includes.c

@@ -22,3 +22,6 @@ int LocalVar;
 
 // TOP: inclusion directive=targeted-nested1.h ({{.*[/\\]}}test{{[/\\]}}Index{{[/\\]}}targeted-nested1.h) =[5:1 - 5:2]
 // TOP: inclusion directive=targeted-fields.h ({{.*[/\\]}}test{{[/\\]}}Index{{[/\\]}}targeted-fields.h) =[16:1 - 16:2]
+
+// rdar://13803893
+// RUN: c-index-test -file-includes-in=%S/Inputs/empty.h %S/Inputs/empty.h