Re: [PATCH] preprocessor/58580 - preprocessor goes OOM with warning for zero literals

[Markus Trippelsdorf <markus at trippelsdorf dot de>]

On 2014.01.24 at 17:09 +0100, Dodji Seketeli wrote:
> Jakub Jelinek <jakub@redhat.com> writes:
> 
> > On Fri, Jan 24, 2014 at 04:40:52PM +0100, Dodji Seketeli wrote:
> >> > The patch causes http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59935 .
> >> > The follow-up patch (fp == NULL check) doesn't help.
> >> 
> >> I am looking into that, sorry for the inconvenience.
> >
> > I'd say we want something like following.  Note that while the c == NULL
> > bailout would be usually sufficient, if you'll do:
> > echo foobar > '<command-line>'
> > it would still crash.  Line 0 is used only for the special locations
> > (command line, built-in macros) and there is no file associated with it
> > anyway.
> >
> > --- gcc/input.c.jj	2014-01-24 16:32:34.000000000 +0100
> > +++ gcc/input.c	2014-01-24 16:41:42.012671452 +0100
> > @@ -698,7 +698,13 @@ location_get_source_line (expanded_locat
> >    static char *buffer;
> >    static ssize_t len;
> >  
> > -  fcache * c = lookup_or_add_file_to_cache_tab (xloc.file);
> > +  if (xloc.line == 0)
> > +    return NULL;
> > +
> > +  fcache *c = lookup_or_add_file_to_cache_tab (xloc.file);
> > +  if (c == NULL)
> > +    return NULL;
> > +
> >    bool read = read_line_num (c, xloc.line, &buffer, &len);
> >  
> >    if (read && line_len)
> 
> Indeed.
> 
> Though, I am testing the patch below that makes read_line_num gracefully
> handle empty caches or zero locations.  The rest of the code should just
> work with that as is.
> 
> 	* input.c (read_line_num): Gracefully handle non-file locations or
> 	empty caches.

Unfortunately this doesn't fix yet another issue:

markus@x4 /tmp % cat foo.c
#line 4636 "configure"
#include <xxxxxxxxxxxx.h>
int main() { return 0; }

markus@x4 /tmp % gcc foo.c
configure:4636:26: fatal error: xxxxxxxxxxxx.h: No such file or directory
gcc: internal compiler error: Segmentation fault (program cc1)
0x40cc8e execute
        ../../gcc/gcc/gcc.c:2841
0x40cf09 do_spec_1
        ../../gcc/gcc/gcc.c:4641
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
0x40d692 do_spec_1
        ../../gcc/gcc/gcc.c:5295
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
0x40d692 do_spec_1
        ../../gcc/gcc/gcc.c:5295
0x40d28e do_spec_1
        ../../gcc/gcc/gcc.c:5410
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
0x40d692 do_spec_1
        ../../gcc/gcc/gcc.c:5295
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
0x40d692 do_spec_1
        ../../gcc/gcc/gcc.c:5295
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
0x40d692 do_spec_1
        ../../gcc/gcc/gcc.c:5295
0x40fc91 process_brace_body
        ../../gcc/gcc/gcc.c:5924
0x40fc91 handle_braces
        ../../gcc/gcc/gcc.c:5838
Please submit a full bug report,
with preprocessed source if appropriate.

-- 
Markus