[Bug fortran/34203] Treat \ as normal character (at least on Windows); diagnose unrecognized escape characters

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

------- Comment #9 from kargl at gcc dot gnu dot org  2007-11-26 23:21 -------
(In reply to comment #8)
> I just committed Steve's patch. Now gfortran uses -fno-backslash by default.
> 
> Now we only need to improve the warning:
> 
> For C gcc warns for:
> 
>   char c[] = "\w";
> 
> a.c:3:14: warning: unknown escape sequence '\w'
> 

Tobias, 

I think that gfortran should not bother with a warning.
A better solution would be to simply list the escape 
sequences that -fbackslash trigger, and state the
all other combinations are not expanded.

I think gfortran definitely wants to avoid the pandora's box
of trigraph, octal, and hexidecimal escaped character sequences.

The following was tested with a "make pdf"

Index: invoke.texi
===================================================================
--- invoke.texi (revision 130454)
+++ invoke.texi (working copy)
@@ -239,6 +239,11 @@ Allow @samp{$} as a valid character in a
 @cindex escape characters
 Change the interpretation of backslashes in string literals
 from a single backslash character to ``C-style'' escape characters.
+The following combinations are expanded \a, \b, \f, \n, \r, \t,
+\v, \\, and \0 to the ASCII characters alert, backspace, form feed,
+newline, carriage return, horizontal tab, vertical tab, backslash,
+and NUL, respectively.  All other combinations of a character preceded
+by \ are unexpanded.

 @item -fmodule-private
 @opindex @code{fmodule-private}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34203