For MinGW hide exported struct variables behind pointers

MinGW apparently can't export/import struct variables from/to a DLL,
so wrap the ones needed by inline.h in exported/imported pointer
variables.

All of the following changes apply to a MinGW build only.

* libguile/gc-freelist.c (scm_i_master_freelist_ptr,
  scm_i_master_freelist2_ptr): New API variables.

* libguile/gc.h (scm_i_freelist_ptr, scm_i_freelist2_ptr,
  scm_i_master_freelist_ptr, scm_i_master_freelist2_ptr): New global
  variable declarations.

* libguile/inline.h (scm_cell): Use scm_i_freelist_ptr and
  scm_i_master_freelist_ptr instead of scm_i_freelist and
  scm_i_master_freelist.
  (scm_double_cell): Use scm_i_freelist2_ptr and
  scm_i_master_freelist2_ptr instead of scm_i_freelist2 and
  scm_i_master_freelist2.

* libguile/threads.c (scm_i_freelist_ptr, scm_i_freelist2_ptr): New
  global variables.

4 files changed, 30 insertions, 2 deletions

diff --git a/libguile/gc-freelist.c b/libguile/gc-freelist.c
index c8824dfb9..ca8a96251 100644
--- a/libguile/gc-freelist.c
+++ b/libguile/gc-freelist.c
@@ -29,7 +29,10 @@
 
 scm_t_cell_type_statistics scm_i_master_freelist;
 scm_t_cell_type_statistics scm_i_master_freelist2;
-
+#ifdef __MINGW32__
+scm_t_cell_type_statistics *scm_i_master_freelist_ptr = &scm_i_master_freelist;
+scm_t_cell_type_statistics *scm_i_master_freelist2_ptr = &scm_i_master_freelist2;
+#endif
 
 
 
diff --git a/libguile/gc.h b/libguile/gc.h
index 3cedeb4eb..72af104d3 100644
--- a/libguile/gc.h
+++ b/libguile/gc.h
@@ -276,7 +276,12 @@ SCM_API scm_i_pthread_key_t scm_i_freelist;
 SCM_API scm_i_pthread_key_t scm_i_freelist2;
 SCM_API struct scm_t_cell_type_statistics scm_i_master_freelist;
 SCM_API struct scm_t_cell_type_statistics scm_i_master_freelist2;
-
+#ifdef __MINGW32__
+SCM_API scm_i_pthread_key_t *scm_i_freelist_ptr;
+SCM_API scm_i_pthread_key_t *scm_i_freelist2_ptr;
+SCM_API struct scm_t_cell_type_statistics *scm_i_master_freelist_ptr;
+SCM_API struct scm_t_cell_type_statistics *scm_i_master_freelist2_ptr;
+#endif
 
 SCM_API unsigned long scm_gc_cells_swept;
 SCM_API unsigned long scm_gc_cells_collected;
diff --git a/libguile/inline.h b/libguile/inline.h
index eae1e22aa..2069c7e20 100644
--- a/libguile/inline.h
+++ b/libguile/inline.h
@@ -109,10 +109,18 @@ SCM
 scm_cell (scm_t_bits car, scm_t_bits cdr)
 {
   SCM z;
+#ifdef __MINGW32__
+  SCM *freelist = SCM_FREELIST_LOC (*scm_i_freelist_ptr);
+#else
   SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist);
+#endif
 
   if (scm_is_null (*freelist))
+#ifdef __MINGW32__
+    z = scm_gc_for_newcell (scm_i_master_freelist_ptr, freelist);
+#else
     z = scm_gc_for_newcell (&scm_i_master_freelist, freelist);
+#endif
   else
     {
       z = *freelist;
@@ -180,10 +188,18 @@ scm_double_cell (scm_t_bits car, scm_t_bits cbr,
 		 scm_t_bits ccr, scm_t_bits cdr)
 {
   SCM z;
+#ifdef __MINGW32__
+  SCM *freelist = SCM_FREELIST_LOC (*scm_i_freelist2_ptr);
+#else
   SCM *freelist = SCM_FREELIST_LOC (scm_i_freelist2);
+#endif
 
   if (scm_is_null (*freelist))
+#ifdef __MINGW32__
+    z = scm_gc_for_newcell (scm_i_master_freelist2_ptr, freelist);
+#else
     z = scm_gc_for_newcell (&scm_i_master_freelist2, freelist);
+#endif
   else
     {
       z = *freelist;
diff --git a/libguile/threads.c b/libguile/threads.c
index 3d6df11eb..95a905c17 100644
--- a/libguile/threads.c
+++ b/libguile/threads.c
@@ -1680,6 +1680,10 @@ scm_dynwind_critical_section (SCM mutex)
 /*** Initialization */
 
 scm_i_pthread_key_t scm_i_freelist, scm_i_freelist2;
+#ifdef __MINGW32__
+scm_i_pthread_key_t *scm_i_freelist_ptr = &scm_i_freelist;
+scm_i_pthread_key_t *scm_i_freelist2_ptr = &scm_i_freelist2;
+#endif
 scm_i_pthread_mutex_t scm_i_misc_mutex;
 
 #if SCM_USE_PTHREAD_THREADS