[Bug c/31804] New: gcc segfaults on very long pointer chains

[Bug c/31804] New: gcc segfaults on very long pointer chains

[rwxr-xr-x at gmx dot de]

$ perl -wle 'print "int", "*" x 999999, "p;"' >try.c && gcc try.c
gcc: Internal error: Segmentation fault (program cc1)
...

$ gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-4.1.1-r3/work/gcc-4.1.1/configure --prefix=/usr
--bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.1.1
--includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/info
--with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include/g++-v4
--host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --disable-altivec
--enable-nls --without-included-gettext --with-system-zlib --disable-checking
--disable-werror --enable-secureplt --disable-libunwind-exceptions
--disable-multilib --disable-libmudflap --disable-libssp --enable-java-awt=gtk
--enable-languages=c,c++,java,fortran --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu
Thread model: posix
gcc version 4.1.1 (Gentoo 4.1.1-r3)

gcc-4.3-20070427 seems to have the same problem.
3.4.6 works fine, but after increasing the number of *'s to 99999999 it says:
cc1: out of memory allocating 1677721600 bytes after a total of 845819904 bytes

So this problem seems to be new in gcc4.


-- 
           Summary: gcc segfaults on very long pointer chains
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rwxr-xr-x at gmx dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804

[Bug c/31804] gcc segfaults on very long pointer chains

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2007-05-03 22:02 -------
you must be kidding.


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rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |WONTFIX


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804

[Bug c/31804] gcc segfaults on very long pointer chains

[fang at csl dot cornell dot edu]

------- Comment #2 from fang at csl dot cornell dot edu  2007-05-04 03:40 -------
adding to personal favorite list :)


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fang at csl dot cornell dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fang at csl dot cornell dot
                   |                            |edu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804

[Bug c/31804] gcc segfaults on very long pointer chains

[bangerth at dealii dot org]

------- Comment #3 from bangerth at dealii dot org  2007-05-04 04:50 -------
(In reply to comment #0)
> $ perl -wle 'print "int", "*" x 999999, "p;"' >try.c && gcc try.c
> gcc: Internal error: Segmentation fault (program cc1)

Yo, dude, that would take a seriously long program to even initialize
that pointer :-)

But seriously, while I do think that we should strive to compile even
programs that are "weird" or "unusual" in their requirements on the 
compiler, I think that this one goes a little overboard. I would,
however, be interested to hear how many levels of pointers gcc
actually *can* compile. I would imagine it's at least a few
hundred, maybe thousand. Maybe you could try to figure out?

Best
  Wolfgang


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bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bangerth at dealii dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804

[Bug c/31804] gcc segfaults on very long pointer chains

[joseph at codesourcery dot com]

------- Comment #4 from joseph at codesourcery dot com  2007-05-04 12:00 -------
Subject: Re:  gcc segfaults on very long pointer chains

On Fri, 4 May 2007, bangerth at dealii dot org wrote:

> But seriously, while I do think that we should strive to compile even
> programs that are "weird" or "unusual" in their requirements on the 
> compiler, I think that this one goes a little overboard. I would,
> however, be interested to hear how many levels of pointers gcc
> actually *can* compile. I would imagine it's at least a few
> hundred, maybe thousand. Maybe you could try to figure out?

That would depend on your stack limit (so the question would really be, 
for each extra MB of stack limit how many more levels can it compile)?  
For such extreme programs I think it's reasonable to expect users to 
increase their stack limit when running the compiler.

Although in this case, it would be reasonably straightforward to make 
c_parser_declarator iterative (with an internal linked list on the parser 
obstack) rather than recursive - if that were actually of use in compiling 
real code with real stack limits.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804

[Bug c/31804] gcc segfaults on very long pointer chains

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2007-12-15 20:46 -------
*** Bug 34308 has been marked as a duplicate of this bug. ***


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dominique dot pelle at free
                   |                            |dot fr


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31804