boehm_gc fails to build on Cygwin

[mhansen]

It fails with

  /bin/sh ./libtool --tag=CC --mode=link gcc -fexceptions -I libatomic_ops/src -g -O2   -o libcord.la -rpath /home/mhansen/sage-4.2/local/lib -version-info 1:3:0 -no-undefined cord/cordbscs.lo cord/cordprnt.lo cord/cordtest.lo cord/cordxtra.lo ./libgc.la 

  *** Warning: This system can not link to static lib archive ./libgc.la.
  *** I have the capability to make that library automatically link in when
  *** you link to this library.  But I can only do this if you have a
  *** shared version of the library, which you do not appear to have.
  rm -fr  .libs/libcord.dll.a
  gcc -shared  cord/.libs/cordbscs.o cord/.libs/cordprnt.o cord/.libs/cordtest.o cord/.libs/cordxtra.o   -o .libs/cygcord-1.dll -Wl,--enable-auto-image-base -Xlinker --out-implib -Xlinker .libs/libcord.dll.a
  Creating library file: .libs/libcord.dll.a
  cord/.libs/cordbscs.o: In function `CORD_from_fn':
  /home/mhansen/sage-4.2/spkg/build/boehm_gc-7.1.p2/src/cord/cordbscs.c:288: undefined reference to `_GC_malloc_atomic'
  /home/mhansen/sage-4.2/spkg/build/boehm_gc-7.1.p2/src/cord/cordbscs.c:298: undefined reference to `_GC_malloc'
  cord/.libs/cordbscs.o: In function `CORD_substr_closure':
  /home/mhansen/sage-4.2/spkg/build/boehm_gc-7.1.p2/src/cord/cordbscs.c:344: undefined reference to `_GC_malloc'

This can be fixed by setting THREADDLLIBS to be empty.

I'll post an updated spkg here shortly.

[mhansen]

The spkg with the above change (active only when $UNAME = "CYGWIN") can be found at  http://sage.math.washington.edu/home/mhansen/boehm_gc-7.1.p3.spkg .

[was]

Mike, I was trying to referee this, but the spkg is missing. Did you delete it? Can you repost it somewhere?

[mhansen]

It should be up now.

[mvngu]

An updated spkg is available at

 http://sage.math.washington.edu/home/mvngu/spkg/standard/boehm/boehm_gc-7.1.p4.spkg

This includes Mike's changes at  http://sage.math.washington.edu/home/mhansen/boehm_gc-7.1.p3.spkg, but based on the boehm_gc spkg in Sage 4.3.3.alpha0.

[mvngu]

I rebased Mike's spkg, reviewed it, built it on Cygwin (winxp1 on boxen.math). The build went fine.

[mvngu]

Merged in the standard spkg repository.