nef.x segfaults on Cygwin

[jpflori]

On my Windows 7 x64 install of 5.6.rc0 I get segfaults in nef.x.

After rebuilding with CFLAGS="-g -O0" I get the following backtrace

Program received signal SIGSEGV, Segmentation fault.
__chkstk_ms () at ../../../src/libgcc/config/i386/cygwin.S:173
173     ../../../src/libgcc/config/i386/cygwin.S: No such file or directory.
(gdb) bt
#0  __chkstk_ms () at ../../../src/libgcc/config/i386/cygwin.S:173
#1  0x004320e5 in part_nef (_P=0x686a0008, _V=0x20064a38, _E=0x20064b40,
    _OUT_PTL=0x6b470008, _codim=0x280c0c, _F=0x22fb7c) at Nefpart.c:774
#2  0x0042e421 in Make_E_Poly (outFILE=0x61187720, _W=0x280de8,
    _CP=0x7c1e0008, _CV=0x2003a0d0, _CE=0x2003a1d8, _codim=0x280c0c,
    _F=0x28ab70, _D=0x280c10) at E_Poly.c:1327
#3  0x00402061 in main (narg=2, fn=0x28ac40) at nef.c:291

on the file

$ cat ../nef.bug
3 6
 1  0  0 -1  0  0
 0  1  0  0 -1  0
 0  0  1  0  0 -1

To fix this, we need to specify the stack size explicitly on Cygwin. This is done in the updated spkg.

install http://boxen.math.washington.edu/home/jpflori/palp-2.1.p1.spkg

CC: @kcrisman @vbraun

Component: packages: standard

Keywords: palp nef.x cygwin segfault

Author: Dmitrii Pasechnik

Reviewer: Jean-Pierre Flori

Merged: sage-5.8.beta0

Issue created by migration from https://trac.sagemath.org/ticket/13960

[jpflori]

comment:1

It seems the stack is too small.
Recompiling with CFLAGS including -Wl,--stack,10000000 (so 10MB) makes the crash disappear.
I guess the best solution would to malloc the problematic stuff on the heap.

[vbraun]

comment:2

Thats a known issue in PALP, everything is done with static sizes for maximal speed.

[jpflori]

comment:3

Ok so we'll use the --stack fix.
Any suggestion on a sensible size?

[vbraun]

comment:5

Why isn't the Cygwin stack 8MB by default, this seems to be a pretty popular value in the Linux world.

[jpflori]

comment:6

No idea, I'll use 8MB then.

[dimpase]

comment:7

I've made the spkg where I put this 8MB stack fix for Cygwin in, please test!

[dimpase]

Description changed:

--- 
+++ 
@@ -24,3 +24,7 @@
  0  1  0  0 -1  0
  0  0  1  0  0 -1
 ```
+
+To fix this, we need to specify the stack size explicitly on Cygwin. This is done in the updated spkg.
+
+**install** http://boxen.math.washington.edu/home/dima/packages/palp-2.1.p1.spkg

[jpflori]

comment:8

There is a typo in the hg commit message, and find funny the quoting you used in spkg-install when adding the necessary magic to CFLAGS.
Is that on purpose?

[dimpase]

comment:9

Replying to @jpflori:

There is a typo in the hg commit message, and find funny the quoting you used in spkg-install when adding the necessary magic to CFLAGS.
Is that on purpose?

none of it is intentional – but it works.