jsemit.h

java script test programing source code

                                 JT_CLR_TAG((sd)->target))
#define SD_SET_BPDELTA(sd,bp)   ((sd)->target = BPDELTA_TO_JT(bp))
#define SD_GET_BPDELTA(sd)      (JS_ASSERT(!JT_HAS_TAG((sd)->target)),        \
                                 JT_TO_BPDELTA((sd)->target))

/* Avoid asserting twice by expanding SD_GET_TARGET in the "then" clause. */
#define SD_SPAN(sd,pivot)       (SD_GET_TARGET(sd)                            \
                                 ? JT_CLR_TAG((sd)->target)->offset - (pivot) \
                                 : 0)

struct JSCodeGenerator {
    JSTreeContext   treeContext;    /* base state: statement info stack, etc. */

    JSArenaPool     *codePool;      /* pointer to thread code arena pool */
    JSArenaPool     *notePool;      /* pointer to thread srcnote arena pool */
    void            *codeMark;      /* low watermark in cg->codePool */
    void            *noteMark;      /* low watermark in cg->notePool */
    void            *tempMark;      /* low watermark in cx->tempPool */

    struct {
        jsbytecode  *base;          /* base of JS bytecode vector */
        jsbytecode  *limit;         /* one byte beyond end of bytecode */
        jsbytecode  *next;          /* pointer to next free bytecode */
        jssrcnote   *notes;         /* source notes, see below */
        uintN       noteCount;      /* number of source notes so far */
        uintN       noteMask;       /* growth increment for notes */
        ptrdiff_t   lastNoteOffset; /* code offset for last source note */
        uintN       currentLine;    /* line number for tree-based srcnote gen */
    } prolog, main, *current;

    const char      *filename;      /* null or weak link to source filename */
    uintN           firstLine;      /* first line, for js_NewScriptFromCG */
    JSPrincipals    *principals;    /* principals for constant folding eval */
    JSAtomList      atomList;       /* literals indexed for mapping */

    intN            stackDepth;     /* current stack depth in script frame */
    uintN           maxStackDepth;  /* maximum stack depth so far */

    JSTryNote       *tryBase;       /* first exception handling note */
    JSTryNote       *tryNext;       /* next available note */
    size_t          tryNoteSpace;   /* # of bytes allocated at tryBase */

    JSSpanDep       *spanDeps;      /* span dependent instruction records */
    JSJumpTarget    *jumpTargets;   /* AVL tree of jump target offsets */
    JSJumpTarget    *jtFreeList;    /* JT_LEFT-linked list of free structs */
    uintN           numSpanDeps;    /* number of span dependencies */
    uintN           numJumpTargets; /* number of jump targets */
    ptrdiff_t       spanDepTodo;    /* offset from main.base of potentially
                                       unoptimized spandeps */

    uintN           arrayCompSlot;  /* stack slot of array in comprehension */

    uintN           emitLevel;      /* js_EmitTree recursion level */
    JSAtomList      constList;      /* compile time constants */
    JSCodeGenerator *parent;        /* Enclosing function or global context */
};

#define CG_BASE(cg)             ((cg)->current->base)
#define CG_LIMIT(cg)            ((cg)->current->limit)
#define CG_NEXT(cg)             ((cg)->current->next)
#define CG_CODE(cg,offset)      (CG_BASE(cg) + (offset))
#define CG_OFFSET(cg)           PTRDIFF(CG_NEXT(cg), CG_BASE(cg), jsbytecode)

#define CG_NOTES(cg)            ((cg)->current->notes)
#define CG_NOTE_COUNT(cg)       ((cg)->current->noteCount)
#define CG_NOTE_MASK(cg)        ((cg)->current->noteMask)
#define CG_LAST_NOTE_OFFSET(cg) ((cg)->current->lastNoteOffset)
#define CG_CURRENT_LINE(cg)     ((cg)->current->currentLine)

#define CG_PROLOG_BASE(cg)      ((cg)->prolog.base)
#define CG_PROLOG_LIMIT(cg)     ((cg)->prolog.limit)
#define CG_PROLOG_NEXT(cg)      ((cg)->prolog.next)
#define CG_PROLOG_CODE(cg,poff) (CG_PROLOG_BASE(cg) + (poff))
#define CG_PROLOG_OFFSET(cg)    PTRDIFF(CG_PROLOG_NEXT(cg), CG_PROLOG_BASE(cg),\
                                        jsbytecode)

#define CG_SWITCH_TO_MAIN(cg)   ((cg)->current = &(cg)->main)
#define CG_SWITCH_TO_PROLOG(cg) ((cg)->current = &(cg)->prolog)

/*
 * Initialize cg to allocate bytecode space from codePool, source note space
 * from notePool, and all other arena-allocated temporaries from cx->tempPool.
 * Return true on success.  Report an error and return false if the initial
 * code segment can't be allocated.
 */
extern JS_FRIEND_API(JSBool)
js_InitCodeGenerator(JSContext *cx, JSCodeGenerator *cg,
                     JSArenaPool *codePool, JSArenaPool *notePool,
                     const char *filename, uintN lineno,
                     JSPrincipals *principals);

/*
 * Release cg->codePool, cg->notePool, and cx->tempPool to marks set by
 * js_InitCodeGenerator.  Note that cgs are magic: they own the arena pool
 * "tops-of-stack" space above their codeMark, noteMark, and tempMark points.
 * This means you cannot alloc from tempPool and save the pointer beyond the
 * next JS_FinishCodeGenerator.
 */
extern JS_FRIEND_API(void)
js_FinishCodeGenerator(JSContext *cx, JSCodeGenerator *cg);

/*
 * Emit one bytecode.
 */
extern ptrdiff_t
js_Emit1(JSContext *cx, JSCodeGenerator *cg, JSOp op);

/*
 * Emit two bytecodes, an opcode (op) with a byte of immediate operand (op1).
 */
extern ptrdiff_t
js_Emit2(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1);

/*
 * Emit three bytecodes, an opcode with two bytes of immediate operands.
 */
extern ptrdiff_t
js_Emit3(JSContext *cx, JSCodeGenerator *cg, JSOp op, jsbytecode op1,
         jsbytecode op2);

/*
 * Emit (1 + extra) bytecodes, for N bytes of op and its immediate operand.
 */
extern ptrdiff_t
js_EmitN(JSContext *cx, JSCodeGenerator *cg, JSOp op, size_t extra);

/*
 * Unsafe macro to call js_SetJumpOffset and return false if it does.
 */
#define CHECK_AND_SET_JUMP_OFFSET(cx,cg,pc,off)                               \
    JS_BEGIN_MACRO                                                            \
        if (!js_SetJumpOffset(cx, cg, pc, off))                               \
            return JS_FALSE;                                                  \
    JS_END_MACRO

#define CHECK_AND_SET_JUMP_OFFSET_AT(cx,cg,off)                               \
    CHECK_AND_SET_JUMP_OFFSET(cx, cg, CG_CODE(cg,off), CG_OFFSET(cg) - (off))

extern JSBool
js_SetJumpOffset(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc,
                 ptrdiff_t off);

/* Test whether we're in a statement of given type. */
extern JSBool
js_InStatement(JSTreeContext *tc, JSStmtType type);

/* Test whether we're in a with statement. */
#define js_InWithStatement(tc)      js_InStatement(tc, STMT_WITH)

/*
 * Test whether atom refers to a global variable (or is a reference error).
 * Return true in *loopyp if any loops enclose the lexical reference, false
 * otherwise.
 */
extern JSBool
js_IsGlobalReference(JSTreeContext *tc, JSAtom *atom, JSBool *loopyp);

/*
 * Push the C-stack-allocated struct at stmt onto the stmtInfo stack.
 */
extern void
js_PushStatement(JSTreeContext *tc, JSStmtInfo *stmt, JSStmtType type,
                 ptrdiff_t top);

/*
 * Push a block scope statement and link blockAtom's object-valued key into
 * tc->blockChain.  To pop this statement info record, use js_PopStatement as
 * usual, or if appropriate (if generating code), js_PopStatementCG.
 */
extern void
js_PushBlockScope(JSTreeContext *tc, JSStmtInfo *stmt, JSAtom *blockAtom,
                  ptrdiff_t top);

/*
 * Pop tc->topStmt.  If the top JSStmtInfo struct is not stack-allocated, it
 * is up to the caller to free it.
 */
extern void
js_PopStatement(JSTreeContext *tc);

/*
 * Like js_PopStatement(&cg->treeContext), also patch breaks and continues
 * unless the top statement info record represents a try-catch-finally suite.
 * May fail if a jump offset overflows.
 */
extern JSBool
js_PopStatementCG(JSContext *cx, JSCodeGenerator *cg);

/*
 * Define and lookup a primitive jsval associated with the const named by atom.
 * js_DefineCompileTimeConstant analyzes the constant-folded initializer at pn
 * and saves the const's value in cg->constList, if it can be used at compile
 * time.  It returns true unless an error occurred.
 *
 * If the initializer's value could not be saved, js_LookupCompileTimeConstant
 * calls will return the undefined value.  js_LookupCompileTimeConstant tries
 * to find a const value memorized for atom, returning true with *vp set to a
 * value other than undefined if the constant was found, true with *vp set to
 * JSVAL_VOID if not found, and false on error.
 */
extern JSBool
js_DefineCompileTimeConstant(JSContext *cx, JSCodeGenerator *cg, JSAtom *atom,
                             JSParseNode *pn);

extern JSBool
js_LookupCompileTimeConstant(JSContext *cx, JSCodeGenerator *cg, JSAtom *atom,
                             jsval *vp);

/*
 * Find a lexically scoped variable (one declared by let, catch, or an array
 * comprehension) named by atom, looking in tc's compile-time scopes.
 *
 * If a WITH statement is reached along the scope stack, return its statement
 * info record, so callers can tell that atom is ambiguous.  If slotp is not
 * null, then if atom is found, set *slotp to its stack slot, otherwise to -1.
 * This means that if slotp is not null, all the block objects on the lexical
 * scope chain must have had their depth slots computed by the code generator,
 * so the caller must be under js_EmitTree.
 *
 * In any event, directly return the statement info record in which atom was
 * found.  Otherwise return null.
 */
extern JSStmtInfo *
js_LexicalLookup(JSTreeContext *tc, JSAtom *atom, jsint *slotp,
                 JSBool letdecl);

/*
 * Emit code into cg for the tree rooted at pn.
 */
extern JSBool
js_EmitTree(JSContext *cx, JSCodeGenerator *cg, JSParseNode *pn);

/*
 * Emit function code into cg for the tree rooted at body.
 */
extern JSBool
js_EmitFunctionBytecode(JSContext *cx, JSCodeGenerator *cg, JSParseNode *body);

/*
 * Emit code into cg for the tree rooted at body, then create a persistent
 * script for fun from cg.
 */
extern JSBool
js_EmitFunctionBody(JSContext *cx, JSCodeGenerator *cg, JSParseNode *body,
                    JSFunction *fun);

/*
 * Source notes generated along with bytecode for decompiling and debugging.