Re: [9.3 bug fix] ECPG does not escape backslashes

On 2013-07-04 08:50:34 -0400, Andrew Dunstan wrote:
>
> On 07/04/2013 08:31 AM, Michael Meskes wrote:
> >On Thu, Jul 04, 2013 at 07:58:39AM -0400, Andrew Dunstan wrote:
> >>>michael@feivel:~$ grep line test\\\\a/init.c |head -1
> >>>#line 1 "test\\a/init.pgc"
> >>...
> >>
> >>Really? I'd expect to see 4 backslashes in the #line directive, I think.
> >Eh, why? The four backslashes come are two that are escaped for shell usage.
> >The directory name is in my example was "test\\a". What did I miss?
> >
>
> Isn't the argument to #line a C string literal in which one would expect
> backslashes to be escaped? If not, how would it show a filename containing a
> '"' character?
>
>    [andrew@emma inst.92.5701]$ bin/ecpg x\\\"a/y.pgc
>    [andrew@emma inst.92.5701]$ grep line  x\\\"a/y.c
>    #line 1 "x\"a/y.pgc"
>
> This must surely be wrong.

I think it's correct. Quoting the gcc manual
(http://gcc.gnu.org/onlinedocs/gcc-4.8.1/cpp/Include-Syntax.html#Include-Syntax)
"However, if backslashes occur within file, they are considered ordinary
text characters, not escape characters. None of the character escape
sequences appropriate to string constants in C are processed. Thus,
#include "x\n\\y" specifies a filename containing three
backslashes. (Some systems interpret ‘\’ as a pathname separator. All of
these also interpret ‘/’ the same way. It is most portable to use only
‘/’.)"

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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