/* object.h: The Scheme object representation, and a few other important * data types. * * $Id$ * * Copyright 1990, 1991, 1992, 1993, 1994, 1995, Oliver Laumann, Berlin * Copyright 2002, 2003 Sam Hocevar , Paris * * This software was derived from Elk 1.2, which was Copyright 1987, 1988, * 1989, Nixdorf Computer AG and TELES GmbH, Berlin (Elk 1.2 has been written * by Oliver Laumann for TELES Telematic Services, Berlin, in a joint project * between TELES and Nixdorf Microprocessor Engineering, Berlin). * * Oliver Laumann, TELES GmbH, Nixdorf Computer AG and Sam Hocevar, as co- * owners or individual owners of copyright in this software, grant to any * person or company a worldwide, royalty free, license to * * i) copy this software, * ii) prepare derivative works based on this software, * iii) distribute copies of this software or derivative works, * iv) perform this software, or * v) display this software, * * provided that this notice is not removed and that neither Oliver Laumann * nor Teles nor Nixdorf are deemed to have made any representations as to * the suitability of this software for any purpose nor are held responsible * for any defects of this software. * * THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. */ #include #include typedef struct { int64_t data; int tag; } Object; #define FIXBITS (8 * (int)sizeof(int)) #define SIGNBIT ((unsigned int)1 << (FIXBITS-1)) #define CONSTBIT 1 #define TYPEBITS (8 * (int)sizeof(int) - 1) #define MAX_TYPE ((1 << TYPEBITS) - 1) #define UFIXNUM_FITS(i) (((i) & SIGNBIT) == 0) #define FIXNUM_FITS(i) 1 #define TYPE(x) ((x).tag >> 1) #define FIXNUM(x) ((int)(x).data) #define CHAR(x) ((int)(x).data) #define POINTER(x) ((void *)(uintptr_t)(x).data) #define SETPOINTER(x,p) ((x).data = (uintptr_t)(void *)(p)) #define SET(x,t,p) ((x).tag = (int)t << 1, (x).data = (p)) #define ISCONST(x) ((x).tag & CONSTBIT) #define SETCONST(x) ((x).tag |= CONSTBIT) #define EQ(x,y) ((x).data == (y).data && (x).tag == (y).tag) /* GC related macros: */ #define WAS_FORWARDED(obj) (TYPE(*(Object *)POINTER(obj)) == T_Broken_Heart) #define UPDATE_OBJ(obj) SETPOINTER(obj, POINTER(*(Object *)POINTER(obj))) #ifdef GENERATIONAL_GC typedef int gcspace_t; /* type for space and type arrays */ typedef uintptr_t gcptr_t; /* type for pointers */ typedef uintptr_t pageno_t; /* type for page numbers */ typedef uintptr_t addrarith_t; /* type for address arithmetic */ extern gcspace_t *space; extern gcspace_t current_space; C_LINKAGE_BEGIN extern int Visit (Object*); /* required for REVIVE_OBJ below */ C_LINKAGE_END # ifdef ARRAY_BROKEN extern pageno_t pagebase; # else # define pagebase ((pageno_t)0) # endif # define PAGEBYTES 512 # define PAGE_TO_OBJ(p) ((Object *) (((p) + pagebase) * PAGEBYTES)) # define OBJ_TO_PAGE(p) ((((gcptr_t)POINTER(p)) / PAGEBYTES) - pagebase) # define STABLE(x) ((~space[(x)]) & 1) # define MAKEOBJ(o,t,p) (SET(o, t, p)) # define IS_ALIVE(obj) ((WAS_FORWARDED(obj)) || \ (STABLE(OBJ_TO_PAGE(obj))) || \ (space[OBJ_TO_PAGE(obj)] == current_space)) # define REVIVE_OBJ(obj) Visit (&obj); #else C_LINKAGE_BEGIN extern int Visit (Object*); /* required in heap.c */ C_LINKAGE_END # define IS_ALIVE(obj) WAS_FORWARDED(obj) # define REVIVE_OBJ(obj) #endif /* Fixed types. Cannot use enum, because the set of types is extensible: */ #define T_Fixnum 0 /* Must be 0 */ #define T_Bignum 1 #define T_Flonum 2 #define T_Null 3 /* empty list */ #define T_Boolean 4 /* #t (1) and #f (0) */ #define T_Unbound 5 /* only used internally */ #define T_Special 6 /* only used internally */ #define T_Character 7 #define T_Symbol 8 #define T_Pair 9 #define T_Environment 10 /* A pair */ #define T_String 11 #define T_Vector 12 #define T_Primitive 13 /* Primitive procedure */ #define T_Compound 14 /* Compound procedure */ #define T_Control_Point 15 #define T_Promise 16 /* Result of (delay expression) */ #define T_Port 17 #define T_End_Of_File 18 #define T_Unspecified 19 /* only used internally */ #define T_Autoload 20 #define T_Macro 21 #define T_Broken_Heart 22 /* only used internally */ #ifdef GENERATIONAL_GC # define T_Align_8Byte 23 /* only used internally */ # define T_Freespace 24 /* only used internally */ #endif #define BIGNUM(x) ((struct S_Bignum *)POINTER(x)) #define FLONUM(x) ((struct S_Flonum *)POINTER(x)) #define STRING(x) ((struct S_String *)POINTER(x)) #define VECTOR(x) ((struct S_Vector *)POINTER(x)) #define SYMBOL(x) ((struct S_Symbol *)POINTER(x)) #define PAIR(x) ((struct S_Pair *)POINTER(x)) #define PRIM(x) ((struct S_Primitive *)POINTER(x)) #define COMPOUND(x) ((struct S_Compound *)POINTER(x)) #define CONTROL(x) ((struct S_Control *)POINTER(x)) #define PROMISE(x) ((struct S_Promise *)POINTER(x)) #define PORT(x) ((struct S_Port *)POINTER(x)) #define AUTOLOAD(x) ((struct S_Autoload *)POINTER(x)) #define MACRO(x) ((struct S_Macro *)POINTER(x)) typedef uint16_t gran_t; /* Granularity of bignums */ struct S_Bignum { Object minusp; unsigned int size; /* Number of uint16_t allocated */ unsigned int usize; /* Number of uint16_t actually used */ gran_t data[1]; /* Data, lsw first */ }; struct S_Flonum { Object tag; /* Each S_Foo must start with an Object */ double val; }; struct S_Symbol { Object value; Object next; Object name; /* A string */ Object plist; }; struct S_Pair { Object car, cdr; }; struct S_String { Object tag; unsigned int size; char data[1]; }; struct S_Vector { Object tag; unsigned int size; Object data[1]; }; enum discipline { EVAL, NOEVAL, VARARGS }; struct S_Primitive { Object tag; Object (*fun) (); const char *name; int minargs; int maxargs; /* Or MANY */ enum discipline disc; }; #define MANY 100 struct S_Compound { Object closure; /* (lambda (args) form ...) */ Object env; /* Procedure's environment */ int min_args, max_args; int numforms; Object name; }; typedef struct wind { struct wind *next, *prev; Object inout; /* Pair of thunks */ } WIND; typedef struct funct { struct funct *next; char *name; void (*func) (void); } FUNCT; typedef struct gcnode { struct gcnode *next; int gclen; Object *gcobj; } GCNODE; typedef struct mem_node { struct mem_node *next; unsigned int len; unsigned long int refcnt; } MEM_NODE; #if defined(vax) || defined(__vax__) typedef int jmp_buf[17]; #else # include #endif struct S_Control { Object env; GCNODE *gclist; MEM_NODE *memlist; Object memsave; /* string */ Object gcsave; /* vector */ WIND *firstwind, *lastwind; int tailcall; intptr_t delta; #ifdef GENERATIONAL_GC int reloc; #endif jmp_buf j; unsigned int size; unsigned long int intrlevel; char stack[1]; /* must be word aligned */ }; struct S_Promise { Object env; Object thunk; int done; }; struct S_Port { Object name; /* string */ uint16_t flags; char unread; unsigned int ptr; FILE *file; unsigned int lno; int (*closefun) (FILE*); }; #define P_OPEN 1 /* flags */ #define P_INPUT 2 #define P_STRING 4 #define P_UNREAD 8 #define P_BIDIR 16 #define IS_INPUT(port) (PORT(port)->flags & (P_INPUT|P_BIDIR)) #define IS_OUTPUT(port) ((PORT(port)->flags & (P_INPUT|P_BIDIR)) != P_INPUT) struct S_Autoload { Object files; Object env; }; struct S_Macro { Object body; int min_args, max_args; Object name; }; /* "size" is called with one object and returns the size of the object. * If "size" is NOFUNC, then "const_size" is taken instead. * "eqv" and "equal" are called with two objects and return 0 or 1. * NOFUNC may be passed instead (then eqv and equal always return #f). * "print" is called with an object, a port, a flag indicating whether * the object is to be printed "raw" (a la display), the print-depth, * and the print-length. * "visit" is called with a pointer to an object and a function. * For each component of the object, the function must be called with * a pointer to the component. NOFUNC may be supplied. */ typedef struct { int haspointer; const char *name; int (*size) (Object); int const_size; int (*eqv) (Object, Object); int (*equal) (Object, Object); int (*print) (Object, Object, int, int, int); int (*visit) (Object*, int (*)(Object*)); } TYPEDESCR; #ifdef ELK_USE_PROTOTYPES # define NOFUNC 0 #else # define NOFUNC ((int (*)())0) #endif typedef struct sym { struct sym *next; char *name; unsigned long int value; } SYM; typedef struct { SYM *first; char *strings; } SYMTAB; typedef struct { char *name; int type; } SYMPREFIX; #define PR_EXTENSION 0 /* Elk extension initializers/finalizers */ #define PR_CONSTRUCTOR 1 /* C++ static constructors/destructors */ /* PFO, GENERIC, and MATCHFUN exist for backwards compatibility */ typedef Object (*PFO) (Object); typedef int (*MATCHFUN) (); #define GENERIC char* typedef struct weak_node { struct weak_node *next; Object obj; PFO term; GENERIC group; char flags; } WEAK_NODE; /* flags */ #define WK_LEADER 1 typedef struct { char *name; unsigned long int val; } SYMDESCR; /* Function that can be registered as a reader by Define_Reader(): */ typedef Object (*READFUN) (Object, int, int);