[PATCH] PR14795 : -frewrite-includes sometimes results in incorrect line number

[Lubos Lunak]

On Thursday 25 of July 2013, Eli Friedman wrote:
> On Tue, Jul 23, 2013 at 12:15 AM, Lubos Lunak <l.lunak at suse.cz> wrote:
> > On Tuesday 16 of July 2013, Eli Friedman wrote:
> >> On Sun, Jul 14, 2013 at 2:16 PM, Lubos Lunak <l.lunak at suse.cz> wrote:
> >> > On Monday 01 of July 2013, Eli Friedman wrote:
> >> >> --- a/lib/Lex/Lexer.cpp
> >> >> +++ b/lib/Lex/Lexer.cpp
> >> >> @@ -2372,8 +2372,9 @@ bool Lexer::LexEndOfFile(Token &Result, const
> >> >> char *CurPtr) {
> >> >>      FormTokenWithChars(Result, CurPtr, tok::eod);
> >> >>
> >> >>      // Restore comment saving mode, in case it was disabled for
> >> >> directive. -    resetExtendedTokenMode();
> >> >> -    return true;  // Have a token.
> >> >> +    if (PP)
> >> >> +      resetExtendedTokenMode();
> >> >> +    return true; // Have a token.
> >> >>    }
> >> >>
> >> >>    // If we are in raw mode, return this event as an EOF token.  Let
> >> >> the caller
> >> >>
> >> >> How is this related?
> >> >
> >> >  I had a crash there without this when I wrote the patch. I don't
> >> > remember the circumstances though and the random testcase I tried
> >> > doesn't trigger it.
> >>
> >> Okay.
> >>
> >> Please commit without this change.
> >
> >  Actually, LibreOffice is always a good testcase, so I can reproduce the
> > crash after all:
...
> >  So I will include that change too, unless somebody sees a better way of
> > avoiding this.
>
> Can you reduce a testcase?

$ echo -ne '#if 0\n#endif' >a.cpp
$ clang++ -frewrite-includes -E a.cpp

(note the lack of the trailing \n)

-- 
 Lubos Lunak
 l.lunak at suse.cz