factor/vm/contexts.hpp

67 lines
1.5 KiB
C++

namespace factor
{
/* Assembly code makes assumptions about the layout of this struct:
- callstack_top field is 0
- callstack_bottom field is 1
- datastack field is 2
- retainstack field is 3 */
struct context {
/* C stack pointer on entry */
stack_frame *callstack_top;
stack_frame *callstack_bottom;
/* current datastack top pointer */
cell datastack;
/* current retain stack top pointer */
cell retainstack;
/* saved contents of ds register on entry to callback */
cell datastack_save;
/* saved contents of rs register on entry to callback */
cell retainstack_save;
/* memory region holding current datastack */
segment *datastack_region;
/* memory region holding current retain stack */
segment *retainstack_region;
/* saved userenv slots on entry to callback */
cell catchstack_save;
cell current_callback_save;
context *next;
};
extern cell ds_size, rs_size;
#define ds_bot (stack_chain->datastack_region->start)
#define ds_top (stack_chain->datastack_region->end)
#define rs_bot (stack_chain->retainstack_region->start)
#define rs_top (stack_chain->retainstack_region->end)
DEFPUSHPOP(d,ds)
DEFPUSHPOP(r,rs)
void reset_datastack();
void reset_retainstack();
void fix_stacks();
void init_stacks(cell ds_size, cell rs_size);
PRIMITIVE(datastack);
PRIMITIVE(retainstack);
PRIMITIVE(set_datastack);
PRIMITIVE(set_retainstack);
PRIMITIVE(check_datastack);
VM_C_API void save_stacks();
VM_C_API void nest_stacks();
VM_C_API void unnest_stacks();
}
VM_C_API factor::context *stack_chain;