/* classes: h_files */ #ifndef SCM_STRUCT_H #define SCM_STRUCT_H /* Copyright (C) 1995,1997,1999-2001, 2006-2013, 2015, * 2017 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA */ #include "libguile/__scm.h" #include "libguile/print.h" /* The relationship between a struct and its vtable is a bit complicated, because we want structs to be used as GOOPS' native representation -- which in turn means we need support for changing the "class" (vtable) of an "instance" (struct). This necessitates some indirection and trickery. To summarize, structs are laid out this way: .-------. | | .----------------+---v------------- - | vtable | data | slot0 | slot1 | `----------------+----------------- - | .-------. | | | .---v------------+---v------------- - | vtable | data | slot0 | slot1 | `----------------+----------------- - | v ... .-------. | | | .---v------------+---v------------- - .-| vtable | data | slot0 | slot1 | | `----------------+----------------- - | ^ `-----' The DATA indirection (which corresponds to `SCM_STRUCT_DATA ()') is necessary to implement class redefinition. For more details, see: http://wingolog.org/archives/2009/11/09/class-redefinition-in-guile */ /* All vtables have the following fields. */ #define SCM_VTABLE_BASE_LAYOUT \ "pr" /* layout */ \ "uh" /* flags */ \ "sr" /* self */ \ "uh" /* finalizer */ \ "pw" /* printer */ \ "ph" /* name (hidden from make-struct for back-compat reasons) */ \ "uh" /* size */ \ "uh" /* reserved */ #define scm_vtable_index_layout 0 /* A symbol describing the physical arrangement of this type. */ #define scm_vtable_index_flags 1 /* Class flags */ #define scm_vtable_index_self 2 /* A pointer to the vtable itself */ #define scm_vtable_index_instance_finalize 3 /* Finalizer for instances of this struct type. */ #define scm_vtable_index_instance_printer 4 /* A printer for this struct type. */ #define scm_vtable_index_name 5 /* Name of this vtable. */ #define scm_vtable_index_size 6 /* Number of fields, for simple structs. */ #define scm_vtable_index_reserved_7 7 #define scm_vtable_offset_user 8 /* Where do user fields start in the vtable? */ /* All applicable structs have the following fields. */ #define SCM_APPLICABLE_BASE_LAYOUT \ "pw" /* procedure */ #define SCM_APPLICABLE_WITH_SETTER_BASE_LAYOUT \ "pw" /* procedure */ \ "pw" /* setter */ #define scm_applicable_struct_index_procedure 0 /* The procedure of an applicable struct. Only valid if the struct's vtable has the applicable flag set. */ #define scm_applicable_struct_index_setter 1 /* The setter of an applicable struct. Only valid if the struct's vtable has the setter flag set. */ #define SCM_VTABLE_FLAG_VALIDATED (1L << 0) /* the layout of this vtable been validated? */ #define SCM_VTABLE_FLAG_VTABLE (1L << 1) /* instances of this vtable are themselves vtables? */ #define SCM_VTABLE_FLAG_APPLICABLE_VTABLE (1L << 2) /* instances of this vtable are applicable vtables? */ #define SCM_VTABLE_FLAG_APPLICABLE (1L << 3) /* instances of this vtable are applicable? */ #define SCM_VTABLE_FLAG_SETTER_VTABLE (1L << 4) /* instances of this vtable are applicable-with-setter vtables? */ #define SCM_VTABLE_FLAG_SETTER (1L << 5) /* instances of this vtable are applicable-with-setters? */ #define SCM_VTABLE_FLAG_SIMPLE (1L << 6) /* instances of this vtable have only "p" fields and no tail array*/ #define SCM_VTABLE_FLAG_SIMPLE_RW (1L << 7) /* instances of this vtable have only "pw" fields and no tail array */ #define SCM_VTABLE_FLAG_RESERVED_0 (1L << 8) #define SCM_VTABLE_FLAG_RESERVED_1 (1L << 9) #define SCM_VTABLE_FLAG_RESERVED_2 (1L << 10) #define SCM_VTABLE_FLAG_SMOB_0 (1L << 11) #define SCM_VTABLE_FLAG_GOOPS_0 (1L << 12) #define SCM_VTABLE_FLAG_GOOPS_1 (1L << 13) #define SCM_VTABLE_FLAG_GOOPS_2 (1L << 14) #define SCM_VTABLE_FLAG_GOOPS_3 (1L << 15) #define SCM_VTABLE_USER_FLAG_SHIFT 16 typedef void (*scm_t_struct_finalize) (SCM obj); #define SCM_STRUCTP(X) (!SCM_IMP(X) && (SCM_TYP3(X) == scm_tc3_struct)) #define SCM_STRUCT_SLOTS(X) ((SCM*)SCM_CELL_WORD_1 ((X))) #define SCM_STRUCT_SLOT_REF(X,I) (SCM_STRUCT_SLOTS (X)[(I)]) #define SCM_STRUCT_SLOT_SET(X,I,V) SCM_STRUCT_SLOTS (X)[(I)]=(V) #define SCM_STRUCT_DATA(X) ((scm_t_bits*)SCM_CELL_WORD_1 (X)) #define SCM_STRUCT_DATA_REF(X,I) (SCM_STRUCT_DATA (X)[(I)]) #define SCM_STRUCT_DATA_SET(X,I,V) SCM_STRUCT_DATA (X)[(I)]=(V) /* The SCM_VTABLE_* macros assume that you're passing them a struct which is a valid vtable. */ #define SCM_VTABLE_LAYOUT(X) (SCM_STRUCT_SLOT_REF ((X), scm_vtable_index_layout)) #define SCM_SET_VTABLE_LAYOUT(X,L) (SCM_STRUCT_SLOT_SET ((X), scm_vtable_index_layout, L)) #define SCM_VTABLE_FLAGS(X) (SCM_STRUCT_DATA_REF (X, scm_vtable_index_flags)) #define SCM_SET_VTABLE_FLAGS(X,F) (SCM_STRUCT_DATA_REF (X, scm_vtable_index_flags) |= (F)) #define SCM_CLEAR_VTABLE_FLAGS(X,F) (SCM_STRUCT_DATA_REF (X, scm_vtable_index_flags) &= (~(F))) #define SCM_VTABLE_FLAG_IS_SET(X,F) (SCM_STRUCT_DATA_REF (X, scm_vtable_index_flags) & (F)) #define SCM_VTABLE_INSTANCE_FINALIZER(X) ((scm_t_struct_finalize)SCM_STRUCT_DATA_REF (X, scm_vtable_index_instance_finalize)) #define SCM_SET_VTABLE_INSTANCE_FINALIZER(X,P) (SCM_STRUCT_DATA_SET (X, scm_vtable_index_instance_finalize, (scm_t_bits)(P))) #define SCM_VTABLE_INSTANCE_PRINTER(X) (SCM_STRUCT_SLOT_REF (X, scm_vtable_index_instance_printer)) #define SCM_SET_VTABLE_INSTANCE_PRINTER(X,P) (SCM_STRUCT_SLOT_SET (X, scm_vtable_index_instance_printer, (P))) #define SCM_VTABLE_NAME(X) (SCM_STRUCT_SLOT_REF (X, scm_vtable_index_name)) #define SCM_SET_VTABLE_NAME(X,V) (SCM_STRUCT_SLOT_SET (X, scm_vtable_index_name, V)) /* Structs hold a pointer to their vtable's data, not the vtable itself. To get the vtable we have to do an indirection through the self slot. */ #define SCM_STRUCT_VTABLE_DATA(X) ((scm_t_bits*)(SCM_CELL_WORD_0 (X) - scm_tc3_struct)) #define SCM_STRUCT_VTABLE_SLOTS(X) ((SCM*)(SCM_CELL_WORD_0 (X) - scm_tc3_struct)) #define SCM_STRUCT_VTABLE(X) (SCM_STRUCT_VTABLE_SLOTS(X)[scm_vtable_index_self]) /* But often we just need to access the vtable's data; we can do that without the data->self->data indirection. */ #define SCM_STRUCT_LAYOUT(X) (SCM_STRUCT_VTABLE_SLOTS (X)[scm_vtable_index_layout]) #define SCM_STRUCT_PRINTER(X) (SCM_STRUCT_VTABLE_SLOTS (X)[scm_vtable_index_instance_printer]) #define SCM_STRUCT_FINALIZER(X) ((scm_t_struct_finalize)SCM_STRUCT_VTABLE_DATA (X)[scm_vtable_index_instance_finalize]) #define SCM_STRUCT_VTABLE_FLAGS(X) (SCM_STRUCT_VTABLE_DATA (X)[scm_vtable_index_flags]) #define SCM_STRUCT_VTABLE_FLAG_IS_SET(X,F) (SCM_STRUCT_VTABLE_DATA (X)[scm_vtable_index_flags]&(F)) #define SCM_STRUCT_APPLICABLE_P(X) (SCM_STRUCT_VTABLE_FLAG_IS_SET ((X), SCM_VTABLE_FLAG_APPLICABLE)) #define SCM_STRUCT_SETTER_P(X) (SCM_STRUCT_VTABLE_FLAG_IS_SET ((X), SCM_VTABLE_FLAG_SETTER)) #define SCM_STRUCT_PROCEDURE(X) (SCM_STRUCT_SLOT_REF (X, scm_applicable_struct_index_procedure)) #define SCM_SET_STRUCT_PROCEDURE(X,P) (SCM_STRUCT_SLOT_SET (X, scm_applicable_struct_index_procedure, P)) #define SCM_STRUCT_SETTER(X) (SCM_STRUCT_SLOT_REF (X, scm_applicable_struct_index_setter)) #define SCM_SET_STRUCT_SETTER(X,P) (SCM_STRUCT_SLOT_SET (X, scm_applicable_struct_index_setter, P)) SCM_API SCM scm_standard_vtable_vtable; SCM_API SCM scm_applicable_struct_vtable_vtable; SCM_API SCM scm_applicable_struct_with_setter_vtable_vtable; SCM_API SCM scm_make_struct_layout (SCM fields); SCM_API SCM scm_struct_p (SCM x); SCM_API SCM scm_struct_vtable_p (SCM x); SCM_INTERNAL SCM scm_allocate_struct (SCM vtable, SCM n_words); SCM_API SCM scm_make_struct_no_tail (SCM vtable, SCM init); SCM_API SCM scm_c_make_struct (SCM vtable, size_t n_tail, size_t n_inits, scm_t_bits init, ...); SCM_API SCM scm_c_make_structv (SCM vtable, size_t n_tail, size_t n_inits, scm_t_bits init[]); SCM_API SCM scm_make_vtable (SCM fields, SCM printer); SCM_INTERNAL SCM scm_i_make_vtable_vtable (SCM fields); SCM_API SCM scm_struct_ref (SCM handle, SCM pos); SCM_API SCM scm_struct_set_x (SCM handle, SCM pos, SCM val); SCM_API SCM scm_struct_ref_unboxed (SCM handle, SCM pos); SCM_API SCM scm_struct_set_x_unboxed (SCM handle, SCM pos, SCM val); SCM_API SCM scm_struct_vtable (SCM handle); SCM_API SCM scm_struct_vtable_name (SCM vtable); SCM_API SCM scm_set_struct_vtable_name_x (SCM vtable, SCM name); SCM_API void scm_print_struct (SCM exp, SCM port, scm_print_state *); SCM_INTERNAL SCM scm_i_struct_equalp (SCM s1, SCM s2); SCM_INTERNAL unsigned long scm_struct_ihashq (SCM, unsigned long, void *); SCM_INTERNAL SCM scm_i_alloc_struct (scm_t_bits *vtable_data, int n_words); SCM_INTERNAL void scm_i_struct_inherit_vtable_magic (SCM vtable, SCM obj); SCM_INTERNAL void scm_init_struct (void); #endif /* SCM_STRUCT_H */ /* Local Variables: c-file-style: "gnu" End: */