expr.h

Go to the documentation of this file.

/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
#pragma once
 
#ifdef __cplusplus
extern "C" {
#endif
 
/*
 * Glenn Fowler
 * AT&T Research
 *
 * expression library definitions
 */
 
#include <ast/ast.h>
#include <inttypes.h>
 
#include <expr/exparse.h>
 
#include <assert.h>
#include <cdt.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <util/agxbuf.h>
#include <util/arena.h>
 
#define EX_VERSION      20000101L
 
/*
 * flags
 */
 
#define EX_CHARSTRING   (1<<0)          /* '...' same as "..."          */
#define EX_UNDECLARED   (1<<9)          /* allow undeclared identifiers */
 
#define EX_ARRAY        (-3)            /* getval() array elt   */
#define EX_CALL         (-2)            /* getval() function call elt   */
#define EX_SCALAR       (-1)            /* getval() scalar elt          */
 
#define EX_NAMELEN      32              /* default Exid_t.name length   */
 
#define EX_ID(n, l, i, t) {{0}, (l), (i), (t), 0, 0, 0, n}
 
#define DELETE_T                MINTOKEN                /* exexpr() delete `type'       */
 
#define INTEGRAL(t)     ((t)>=INTEGER&&(t)<=CHARACTER)
#define BUILTIN(t)  ((t) > MINTOKEN)
 
/* function type mechanism
 * types are encoded in TBITS
 * Thus, maximum # of parameters, including return type,
 * is sizeof(Exid_t.type)/TBITS. Also see T in exgram.h
 */
 
/*
 * arg 0 is the return value type
 */
 
#define F               01              /* FLOATING                     */
#define I               02              /* INTEGER                      */
#define S               03              /* STRING                       */
 
#define TBITS           4
#define TMASK           ((1<<TBITS)-1)
#define A(n,t)          ((t)<<((n)*TBITS))      /* function arg n is type t     */
#define N(t)            ((t)>>=TBITS)   /* shift for next arg           */
 
typedef EX_STYPE Extype_t;
 
typedef union Exdata_u Exdata_t;
typedef struct Exdisc_s Exdisc_t;
typedef struct Exnode_s Exnode_t;
typedef struct Expr_s Expr_t;
typedef struct Exref_s Exref_t;
 
typedef void (*Exerror_f) (Expr_t *, Exdisc_t *, int, const char *, ...);
typedef void (*Exexit_f)(void *, int);
 
typedef struct Exid_s                   /* id symbol table info         */
{
        Dtlink_t        link;           /* symbol table link            */
        long            lex;            /* lex class                    */
        long            index;          /* user defined index           */
        long            type;           /* symbol and arg types         */
        long            index_type;     /* index type for arrays        */
        Exnode_t*       value;          /* value                        */
        void *local; 
        char            name[EX_NAMELEN];/* symbol name                 */
} Exid_t;
 
struct Exref_s                          /* . reference list             */
{
        Exref_t*        next;           /* next in list                 */
        Exid_t*         symbol;         /* reference id symbol          */
        Exnode_t*       index;          /* optional reference index     */
};
 
union Exdata_u
{
 
        struct
        {
        Extype_t        value;          /* constant value               */
        Exid_t*         reference;      /* conversion reference symbol  */
        }               constant;       /* variable reference           */
 
        struct
        {
        Exnode_t*       left;           /* left operand                 */
        Exnode_t*       right;          /* right operand                */
        }               operand;        /* operands                     */
 
        struct
        {
        Exnode_t*       statement;      /* case label statement(s)      */
        Exnode_t*       next;           /* next case item               */
        Extype_t**      constant;       /* case label constant array    */
        }               select;         /* case item                    */
 
        struct
        {
        Exid_t*         symbol;         /* id symbol table entry        */
        Exref_t*        reference;      /* . reference list             */
        Exnode_t*       index;          /* array index expression       */
        Exnode_t*       dyna;           /* dynamic expression           */
        }               variable;       /* variable reference           */
 
#ifdef _EX_DATA_PRIVATE_
        _EX_DATA_PRIVATE_
#endif
 
};
 
struct Exnode_s                         /* expression tree node         */
{
        long    type; 
        long op; 
        bool binary; 
        Exdata_t        data;           /* node data                    */
 
#ifdef _EX_NODE_PRIVATE_
        _EX_NODE_PRIVATE_
#endif
 
};
 
struct Exdisc_s                         /* discipline                   */
{
        uint64_t        version;        /* EX_VERSION                   */
        uint64_t        flags;          /* EX_* flags                   */
        Exid_t*         symbols;        /* static symbols               */
        char**          data;           /* compiled function arg data   */
        int             (*castf)(Expr_t*, Exnode_t*, const char*, int, Exid_t*, int, Exdisc_t*);
                                        /* unknown cast function        */
        int (*convertf)(Exnode_t *, long, int);
                                        /* type conversion function     */
        int             (*binaryf) (Exnode_t *, Exnode_t *, Exnode_t *, int);
                                        /* binary operator function     */
        char *(*typename)(long);
                                        /* application type names       */
        int             (*stringof) (Expr_t *, Exnode_t *, int);
                                        /* value to string conversion   */
        Extype_t (*keyf)(Extype_t, long);
                                        /* dictionary key for external type objects     */
        Exerror_f       errorf;         /* error function               */
        Extype_t        (*getf)(Expr_t*, Exnode_t*, Exid_t*, Exref_t*, void*, int, Exdisc_t*);
                                        /* get value function           */
        Extype_t        (*reff)(Expr_t*, Exnode_t*, Exid_t*, Exref_t*);
                                        /* reference value function     */
        int             (*setf)(Expr_t*, Exnode_t*, Exid_t*, Exref_t*, void*, Extype_t);
                                        /* set value function           */
        Extype_t        (*lengthf)(Exid_t *rhs, Exdisc_t *disc);
        int             (*inf)(Extype_t lhs, Exid_t *rhs, Exdisc_t *disc);
        /* exit function           */
        Exexit_f        exitf;
        int*            types;
        void*           user;
};
 
struct Expr_s                           /* ex program state             */
{
        const char*     id;             /* library id                   */
        Dt_t*           symbols;        /* symbol table                 */
        FILE*           file[10];       /* io streams                   */
        arena_t         vm;             /* program store                */
 
#ifdef _EX_PROG_PRIVATE_
        _EX_PROG_PRIVATE_
#endif
 
};
 
extern Exnode_t *excast(Expr_t *, Exnode_t *, long, Exnode_t *, int);
extern Exnode_t*        exnoncast(Exnode_t *);
extern void exclose(Expr_t *);
 
extern int excomp(Expr_t *p, const char *name, int line, FILE *fp,
                  char *prefix);
 
extern char*            excontext(Expr_t*, char*, int);
extern void exdump(Expr_t *, Exnode_t *, agxbuf *);
#ifdef __GNUC__
__attribute__((format(printf, 1, 2)))
#endif
extern void             exerror(const char*, ...);
#ifdef __GNUC__
__attribute__((format(printf, 1, 2)))
#endif
extern void             exwarn(const char *, ...);
extern Extype_t         exeval(Expr_t*, Exnode_t*, void*);
extern Exnode_t*        exexpr(Expr_t*, const char*, Exid_t*, int);
extern void             exfreenode(Expr_t*, Exnode_t*);
extern Exnode_t *exnewnode(Expr_t *, long, bool, long, Exnode_t *, Exnode_t *);
extern char*            exnospace(void);
extern Expr_t*          exopen(Exdisc_t*);
extern int              expop(Expr_t*);
extern int              expush(Expr_t*, const char*, int, FILE*);
extern int              extoken_fn(Expr_t*);
extern char*            exstring(Expr_t *, char *);
extern void*            exstralloc(Expr_t *, size_t);
extern char* extype(long int);
extern Extype_t exzero(long int);
extern char *exopname(long);
extern void             exinit(void);
extern char *extypename(Expr_t *p, long);
extern int              exisAssign(Exnode_t *);
 
#ifdef __GNUC__
__attribute__((format(printf, 2, 3)))
#endif
static inline char *exprintf(arena_t *vm, const char *fmt, ...) {
  va_list ap;
  va_start(ap, fmt);
 
  // how many bytes do we need for this string?
  va_list ap2;
  va_copy(ap2, ap);
  int len = vsnprintf(NULL, 0, fmt, ap2);
  assert(len >= 0 && "invalid vsnprintf call");
  ++len; // for NUL terminator
  va_end(ap2);
 
  // ask arena for enough space for this
  char *const s = gv_arena_alloc(vm, 1, (size_t)len);
 
  // construct the output string
  (void)vsnprintf(s, (size_t)len, fmt, ap);
  va_end(ap);
 
  return s;
}
 
#ifdef __cplusplus
}
#endif