jsparse.h

java script test programing source code

 *
 * So an XML tag with no {expr} and three attributes is a list with the form:
 *
 *    (tagname attrname1 attrvalue1 attrname2 attrvalue2 attrname2 attrvalue3)
 *
 * An XML tag with embedded expressions like so:
 *
 *    <name1{expr1} name2{expr2}name3={expr3}>
 *
 * would have the form:
 *
 *    ((name1 {expr1}) (name2 {expr2} name3) {expr3})
 *
 * where () bracket a list with elements separated by spaces, and {expr} is a
 * TOK_LC unary node with expr as its kid.
 *
 * Thus, the attribute name/value pairs occupy successive odd and even list
 * locations, where pn_head is the TOK_XMLNAME node at list location 0.  The
 * parser builds the same sort of structures for elements:
 *
 *    <a x={x}>Hi there!<b y={y}>How are you?</b><answer>{x + y}</answer></a>
 *
 * translates to:
 *
 *    ((a x {x}) 'Hi there!' ((b y {y}) 'How are you?') ((answer) {x + y}))
 *
 * <Non-E4X node descriptions, continued>
 *
 * Label              Variant   Members
 * -----              -------   -------
 * TOK_LEXICALSCOPE   name      pn_op: JSOP_LEAVEBLOCK or JSOP_LEAVEBLOCKEXPR
 *                              pn_atom: block object
 *                              pn_expr: block body
 * TOK_ARRAYCOMP      list      pn_head: list of pn_count (1 or 2) elements
 *                              if pn_count is 2, first element is #n=[...]
 *                                last element is block enclosing for loop(s)
 *                                and optionally if-guarded TOK_ARRAYPUSH
 *                              pn_extra: stack slot, used during code gen
 * TOK_ARRAYPUSH      unary     pn_op: JSOP_ARRAYCOMP
 *                              pn_kid: array comprehension expression
 */
typedef enum JSParseNodeArity {
    PN_FUNC     = -3,
    PN_LIST     = -2,
    PN_TERNARY  =  3,
    PN_BINARY   =  2,
    PN_UNARY    =  1,
    PN_NAME     = -1,
    PN_NULLARY  =  0
} JSParseNodeArity;

struct JSParseNode {
    uint16              pn_type;
    uint8               pn_op;
    int8                pn_arity;
    JSTokenPos          pn_pos;
    ptrdiff_t           pn_offset;      /* first generated bytecode offset */
    union {
        struct {                        /* TOK_FUNCTION node */
            JSAtom      *funAtom;       /* atomized function object */
            JSParseNode *body;          /* TOK_LC list of statements */
            uint32      flags;          /* accumulated tree context flags */
            uint32      tryCount;       /* count of try statements in body */
        } func;
        struct {                        /* list of next-linked nodes */
            JSParseNode *head;          /* first node in list */
            JSParseNode **tail;         /* ptr to ptr to last node in list */
            uint32      count;          /* number of nodes in list */
            uint32      extra;          /* extra flags, see below */
        } list;
        struct {                        /* ternary: if, for(;;), ?: */
            JSParseNode *kid1;          /* condition, discriminant, etc. */
            JSParseNode *kid2;          /* then-part, case list, etc. */
            JSParseNode *kid3;          /* else-part, default case, etc. */
        } ternary;
        struct {                        /* two kids if binary */
            JSParseNode *left;
            JSParseNode *right;
            jsval       val;            /* switch case value */
        } binary;
        struct {                        /* one kid if unary */
            JSParseNode *kid;
            jsint       num;            /* -1 or sharp variable number */
        } unary;
        struct {                        /* name, labeled statement, etc. */
            JSAtom      *atom;          /* name or label atom, null if slot */
            JSParseNode *expr;          /* object or initializer */
            jsint       slot;           /* -1 or arg or local var slot */
            uintN       attrs;          /* attributes if local var or const */
        } name;
        struct {
            JSAtom      *atom;          /* first atom in pair */
            JSAtom      *atom2;         /* second atom in pair or null */
        } apair;
        jsdouble        dval;           /* aligned numeric literal value */
    } pn_u;
    JSParseNode         *pn_next;       /* to align dval and pn_u on RISCs */
    JSTokenStream       *pn_ts;         /* token stream for error reports */
    JSAtom              *pn_source;     /* saved source for decompilation */
};

#define pn_funAtom      pn_u.func.funAtom
#define pn_body         pn_u.func.body
#define pn_flags        pn_u.func.flags
#define pn_tryCount     pn_u.func.tryCount
#define pn_head         pn_u.list.head
#define pn_tail         pn_u.list.tail
#define pn_count        pn_u.list.count
#define pn_extra        pn_u.list.extra
#define pn_kid1         pn_u.ternary.kid1
#define pn_kid2         pn_u.ternary.kid2
#define pn_kid3         pn_u.ternary.kid3
#define pn_left         pn_u.binary.left
#define pn_right        pn_u.binary.right
#define pn_val          pn_u.binary.val
#define pn_kid          pn_u.unary.kid
#define pn_num          pn_u.unary.num
#define pn_atom         pn_u.name.atom
#define pn_expr         pn_u.name.expr
#define pn_slot         pn_u.name.slot
#define pn_attrs        pn_u.name.attrs
#define pn_dval         pn_u.dval
#define pn_atom2        pn_u.apair.atom2

/* PN_LIST pn_extra flags. */
#define PNX_STRCAT      0x01            /* TOK_PLUS list has string term */
#define PNX_CANTFOLD    0x02            /* TOK_PLUS list has unfoldable term */
#define PNX_POPVAR      0x04            /* TOK_VAR last result needs popping */
#define PNX_FORINVAR    0x08            /* TOK_VAR is left kid of TOK_IN node,
                                           which is left kid of TOK_FOR */
#define PNX_ENDCOMMA    0x10            /* array literal has comma at end */
#define PNX_XMLROOT     0x20            /* top-most node in XML literal tree */
#define PNX_GROUPINIT   0x40            /* var [a, b] = [c, d]; unit list */
#define PNX_NEEDBRACES  0x80            /* braces necessary due to closure */

/*
 * Move pn2 into pn, preserving pn->pn_pos and pn->pn_offset and handing off
 * any kids in pn2->pn_u, by clearing pn2.
 */
#define PN_MOVE_NODE(pn, pn2)                                                 \
    JS_BEGIN_MACRO                                                            \
        (pn)->pn_type = (pn2)->pn_type;                                       \
        (pn)->pn_op = (pn2)->pn_op;                                           \
        (pn)->pn_arity = (pn2)->pn_arity;                                     \
        (pn)->pn_u = (pn2)->pn_u;                                             \
        PN_CLEAR_NODE(pn2);                                                   \
    JS_END_MACRO

#define PN_CLEAR_NODE(pn)                                                     \
    JS_BEGIN_MACRO                                                            \
        (pn)->pn_type = TOK_EOF;                                              \
        (pn)->pn_op = JSOP_NOP;                                               \
        (pn)->pn_arity = PN_NULLARY;                                          \
    JS_END_MACRO

/* True if pn is a parsenode representing a literal constant. */
#define PN_IS_CONSTANT(pn)                                                    \
    ((pn)->pn_type == TOK_NUMBER ||                                           \
     (pn)->pn_type == TOK_STRING ||                                           \
     ((pn)->pn_type == TOK_PRIMARY && (pn)->pn_op != JSOP_THIS))

/*
 * Compute a pointer to the last JSParseNode element in a singly-linked list.
 * NB: list must be non-empty for correct PN_LAST usage!
 */
#define PN_LAST(list) \
    ((JSParseNode *)((char *)(list)->pn_tail - offsetof(JSParseNode, pn_next)))

#define PN_INIT_LIST(list)                                                    \
    JS_BEGIN_MACRO                                                            \
        (list)->pn_head = NULL;                                               \
        (list)->pn_tail = &(list)->pn_head;                                   \
        (list)->pn_count = (list)->pn_extra = 0;                              \
    JS_END_MACRO

#define PN_INIT_LIST_1(list, pn)                                              \
    JS_BEGIN_MACRO                                                            \
        (list)->pn_head = (pn);                                               \
        (list)->pn_tail = &(pn)->pn_next;                                     \
        (list)->pn_count = 1;                                                 \
        (list)->pn_extra = 0;                                                 \
    JS_END_MACRO

#define PN_APPEND(list, pn)                                                   \
    JS_BEGIN_MACRO                                                            \
        *(list)->pn_tail = (pn);                                              \
        (list)->pn_tail = &(pn)->pn_next;                                     \
        (list)->pn_count++;                                                   \
    JS_END_MACRO

/*
 * Parse a top-level JS script.
 *
 * The caller must prevent the GC from running while this function is active,
 * because atoms and function newborns are not rooted yet.
 */
extern JS_FRIEND_API(JSParseNode *)
js_ParseTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts);

extern JS_FRIEND_API(JSBool)
js_CompileTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts,
                      JSCodeGenerator *cg);

extern JSBool
js_CompileFunctionBody(JSContext *cx, JSTokenStream *ts, JSFunction *fun);

extern JSBool
js_FoldConstants(JSContext *cx, JSParseNode *pn, JSTreeContext *tc);

#if JS_HAS_XML_SUPPORT
JS_FRIEND_API(JSParseNode *)
js_ParseXMLTokenStream(JSContext *cx, JSObject *chain, JSTokenStream *ts,
                       JSBool allowList);
#endif

JS_END_EXTERN_C

#endif /* jsparse_h___ */