[Bug preprocessor/49973] Column numbers count special characters as multiple columns

["egallager at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49973

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |egallager at gcc dot gnu.org
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=69664

--- Comment #12 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Manuel López-Ibáñez from comment #11)
> This should be fixed in libcpp, probably in lex.c, but maybe other places
> also. A good testcase to start with would be:
> 
> /* ñ /* */
> /* a /* */
> 
> cc1 -Wcomment
> 
> prog.cc:1:7: warning: "/*" within comment [-Wcomment]
>  /* ñ /* */
>        ^
> prog.cc:2:6: warning: "/*" within comment [-Wcomment]
>  /* a /* */
>       ^
> 
> Both locations should point to column 6. Look for places where column info
> is converted to source_location (linemap_position_for_column or
> linemap_position_for_line_and_colum). Figure out where the column info got
> the wrong value. Use something like wcwidth() to measure the width of
> non-ASCII characters and get the right width of 'ñ'.
> 
> Unfortunately, GCC 6 seems to be broken for the above testcase
> (https://gcc.gnu.org/PR69664). Revision 229665 seems fine.

Bug 69664 is fixed now.