garbage: allow for building ecl without bdwgc and with nogc

In that case we use a dummy object nogc.o that contains stubs for GC-related
functions. It also defines a substitute module.

src/c/mem_nogc.d

@@ -0,0 +1,68 @@
+/* -*- Mode: C; c-basic-offset: 2; indent-tabs-mode: nil -*- */
+/* vim: set filetype=c tabstop=2 shiftwidth=2 expandtab: */
+
+/* mem_nogc.d - this is a reference of what GC should minimally implement */
+
+/* -- imports ---------------------------------------------------------------- */
+
+#include <ecl/ecl.h>
+#include <ecl/ecl-inl.h>
+#include <ecl/internal.h>
+#include <ecl/external.h>
+
+/* -- implementation --------------------------------------------------------- */
+
+void _ecl_set_max_heap_size(size_t new_size) {}
+void ecl_register_root(cl_object *p) {}
+void ecl_set_finalizer_unprotected(cl_object o, cl_object f) {}
+
+cl_object
+si_gc(cl_narg narg, ...)
+{
+  const cl_env_ptr the_env = ecl_process_env();
+  ecl_return0(the_env);
+}
+
+cl_object
+si_get_finalizer(cl_object o)
+{
+  const cl_env_ptr the_env = ecl_process_env();
+  ecl_return0(the_env);
+}
+
+cl_object
+si_set_finalizer(cl_object o, cl_object f)
+{
+  const cl_env_ptr the_env = ecl_process_env();
+  ecl_return0(the_env);
+}
+
+cl_object
+si_make_weak_pointer(cl_object o)
+{
+  const cl_env_ptr the_env = ecl_process_env();
+  ecl_return1(the_env, ECL_NIL);
+}
+
+cl_object
+si_weak_pointer_value(cl_object o)
+{
+  const cl_env_ptr the_env = ecl_process_env();
+  ecl_return2(the_env, ECL_NIL, ECL_NIL);
+}
+
+ecl_def_ct_base_string(str_gc, "NO-GC", 5, static, const);
+
+static struct ecl_module module_gc = {
+  .name = str_gc,
+  .create = ecl_module_no_op,
+  .enable = ecl_module_no_op,
+  .init_env = ecl_module_no_op_env,
+  .init_cpu = ecl_module_no_op_cpu,
+  .free_cpu = ecl_module_no_op_cpu,
+  .free_env = ecl_module_no_op_env,
+  .disable = ecl_module_no_op,
+  .destroy = ecl_module_no_op
+};
+
+cl_object ecl_module_gc = (cl_object)&module_gc;

src/c/unixint.d

@@ -610,8 +610,10 @@ asynchronous_signal_servicing_thread()
       interrupt_signal =
         ecl_option_values[ECL_OPT_THREAD_INTERRUPT_SIGNAL];
       sigdelset(&handled_set, interrupt_signal);
+#ifdef GBC_BOEHM
       sigdelset(&handled_set, GC_get_suspend_signal());
       sigdelset(&handled_set, GC_get_thr_restart_signal());
+#endif /* GBC_BOEHM */
       sigdelset(&handled_set, SIGSEGV);
       sigdelset(&handled_set, SIGBUS);
     }

src/configure

@@ -7214,7 +7214,7 @@ if test "${enable_threads}" = "yes" ; then
     as_fn_error $? "Threads aren't supported on this system." "$LINENO" 5
   else
     LIBS="${THREAD_LIBS} ${LIBS}"
-    CFLAGS="${CFLAGS} ${THREAD_CFLAGS} -DGC_NO_THREAD_REDIRECTS"
+    CFLAGS="${CFLAGS} ${THREAD_CFLAGS}"
 
 ac_fn_c_check_func "$LINENO" "pthread_rwlock_init" "ac_cv_func_pthread_rwlock_init"
 if test "x$ac_cv_func_pthread_rwlock_init" = xyes
@@ -7271,7 +7271,12 @@ else
 fi
 
 if test ${enable_boehm} = "no" ; then
-  as_fn_error $? "Boehm GC library is currently needed to build ECL" "$LINENO" 5;
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: WARNING: Building ECL without Boehm GC library" >&5
+printf "%s\n" "$as_me: WARNING: Building ECL without Boehm GC library" >&2;};
+
+LSP_FEATURES="${LSP_FEATURES} :dummy-gc"
+
+  EXTRA_OBJS="${EXTRA_OBJS} mem_nogc.${OBJEXT}"
 else
 
 

src/configure.ac

@@ -602,7 +602,9 @@ fi
 dnl ----------------------------------------------------------------------
 dnl		Boehm-Weiser garbage collector
 if test ${enable_boehm} = "no" ; then
-  AC_MSG_ERROR([Boehm GC library is currently needed to build ECL]);
+  AC_MSG_WARN([Building ECL without Boehm GC library]);
+  ECL_ADD_FEATURE(dummy-gc)
+  EXTRA_OBJS="${EXTRA_OBJS} mem_nogc.${OBJEXT}"
 else
   ECL_BOEHM_GC
   ECL_ADD_FEATURE(boehm-gc)

src/h/external.h

@@ -798,14 +798,12 @@ extern ECL_API cl_object cl_format _ECL_ARGS((cl_narg narg, cl_object stream, cl
 #define GC_enabled() !GC_is_disabled()
 #define GC_enable() GC_enable()
 #define GC_disable() GC_disable()
-extern ECL_API void ecl_register_root(cl_object *p);
-extern ECL_API cl_object si_gc(cl_narg narg, ...);
 extern ECL_API cl_object si_gc_dump(void);
 extern ECL_API cl_object si_gc_stats(cl_object enable);
-#else
-# error "IMPLEMENT ME!"
 #endif /* GBC_BOEHM */
 
+extern ECL_API void ecl_register_root(cl_object *p);
+extern ECL_API cl_object si_gc(cl_narg narg, ...);
 
 /* gfun.c */
 

src/h/internal.h

@@ -59,9 +59,7 @@ extern void _ecl_dealloc_env(cl_env_ptr);
 
 /* mem_bdwgc.d */
 
-#ifdef GBC_BOEHM
 #define ECL_COMPACT_OBJECT_EXTRA(x) ((void*)((x)->array.displaced))
-#endif
 extern void _ecl_set_max_heap_size(size_t new_size);
 extern cl_object ecl_alloc_bytecodes(cl_index data_size, cl_index code_size);
 extern cl_index ecl_object_byte_size(cl_type t);

src/lsp/config.lsp.in

@@ -109,14 +109,6 @@ Returns, as a string, the version of the software under which ECL runs."
               aux
               nil))))
 
-;;
-;; * Set up some room
-;;
-#-boehm-gc
-(progn
-  (sys::allocate 'CONS 200)
-  (sys::allocate 'BASE-STRING 40))
-
 ;;
 ;; * Set configuration pathnames. Notice the trailing slash!
 ;;   Otherwise it would not be a directory.