[cfe-commits] r49535 - /cfe/trunk/lib/Lex/Lexer.cpp

[Neil Booth]

Chris Lattner wrote:-

> Author: lattner
> Date: Fri Apr 11 11:20:41 2008
> New Revision: 49535
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=49535&view=rev
> Log:
> don't read off the front of the buffer.  Thanks to Sam for pointing this out.
> 
> Modified:
>     cfe/trunk/lib/Lex/Lexer.cpp
> 
> Modified: cfe/trunk/lib/Lex/Lexer.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/Lexer.cpp?rev=49535&r1=49534&r2=49535&view=diff
> 
> ==============================================================================
> --- cfe/trunk/lib/Lex/Lexer.cpp (original)
> +++ cfe/trunk/lib/Lex/Lexer.cpp Fri Apr 11 11:20:41 2008
> @@ -1142,7 +1142,7 @@
>    }
>    
>    // If the file was empty or didn't end in a newline, issue a pedwarn.
> -  if (CurPtr[-1] != '\n' && CurPtr[-1] != '\r')
> +  if (CurPtr == BufferStart || (CurPtr[-1] != '\n' && CurPtr[-1] != '\r'))
>      Diag(BufferEnd, diag::ext_no_newline_eof);

I don't think this is right Chris.  This will warn about an empty
file; the standard explicitly gives empty files a free pass.  The
following text is the reason for the existence of this diagnostic
(5.1.1.2p2):

	A source file that is not empty shall end in a new-line character,
	which shall not be immediately preceded by a backslash character
	before any such splicing takes place.

Perhaps CurPtr != BufferStart && is what you want?

Neil.