Merged Whippet into libguile/whippet

libguile/whippet/api/gc-ref.h

@@ -0,0 +1,50 @@
+#ifndef GC_REF_H
+#define GC_REF_H
+
+#include "gc-assert.h"
+#include "gc-config.h"
+
+#include <stdint.h>
+
+struct gc_ref {
+  uintptr_t value;
+};
+
+static inline struct gc_ref gc_ref(uintptr_t value) {
+  return (struct gc_ref){value};
+}
+static inline uintptr_t gc_ref_value(struct gc_ref ref) {
+  return ref.value;
+}
+
+static inline struct gc_ref gc_ref_null(void) {
+  return gc_ref(0);
+}
+static inline int gc_ref_is_null(struct gc_ref ref) {
+  return ref.value == 0;
+}
+static inline int gc_ref_is_immediate(struct gc_ref ref) {
+  GC_ASSERT(!gc_ref_is_null(ref));
+  return GC_HAS_IMMEDIATES && (ref.value & (sizeof(void*) - 1));
+}
+static inline struct gc_ref gc_ref_immediate(uintptr_t val) {
+  GC_ASSERT(val & (sizeof(void*) - 1));
+  GC_ASSERT(GC_HAS_IMMEDIATES);
+  return gc_ref(val);
+}
+static inline int gc_ref_is_heap_object(struct gc_ref ref) {
+  return !gc_ref_is_immediate(ref);
+}
+static inline struct gc_ref gc_ref_from_heap_object_or_null(void *obj) {
+  return gc_ref((uintptr_t) obj);
+}
+static inline struct gc_ref gc_ref_from_heap_object(void *obj) {
+  GC_ASSERT(obj);
+  return gc_ref_from_heap_object_or_null(obj);
+}
+static inline void* gc_ref_heap_object(struct gc_ref ref) {
+  GC_ASSERT(gc_ref_is_heap_object(ref));
+  return (void *) gc_ref_value(ref);
+}
+
+#endif // GC_REF_H