jsemit.c

java script test programing source code

}

typedef struct AddJumpTargetArgs {
    JSContext           *cx;
    JSCodeGenerator     *cg;
    ptrdiff_t           offset;
    JSJumpTarget        *node;
} AddJumpTargetArgs;

static int
AddJumpTarget(AddJumpTargetArgs *args, JSJumpTarget **jtp)
{
    JSJumpTarget *jt;
    int balanceDelta;

    jt = *jtp;
    if (!jt) {
        JSCodeGenerator *cg = args->cg;

        jt = cg->jtFreeList;
        if (jt) {
            cg->jtFreeList = jt->kids[JT_LEFT];
        } else {
            JS_ARENA_ALLOCATE_CAST(jt, JSJumpTarget *, &args->cx->tempPool,
                                   sizeof *jt);
            if (!jt) {
                JS_ReportOutOfMemory(args->cx);
                return 0;
            }
        }
        jt->offset = args->offset;
        jt->balance = 0;
        jt->kids[JT_LEFT] = jt->kids[JT_RIGHT] = NULL;
        cg->numJumpTargets++;
        args->node = jt;
        *jtp = jt;
        return 1;
    }

    if (jt->offset == args->offset) {
        args->node = jt;
        return 0;
    }

    if (args->offset < jt->offset)
        balanceDelta = -AddJumpTarget(args, &jt->kids[JT_LEFT]);
    else
        balanceDelta = AddJumpTarget(args, &jt->kids[JT_RIGHT]);
    if (!args->node)
        return 0;

    jt->balance += balanceDelta;
    return (balanceDelta && jt->balance)
           ? 1 - BalanceJumpTargets(jtp)
           : 0;
}

#ifdef DEBUG_brendan
static int AVLCheck(JSJumpTarget *jt)
{
    int lh, rh;

    if (!jt) return 0;
    JS_ASSERT(-1 <= jt->balance && jt->balance <= 1);
    lh = AVLCheck(jt->kids[JT_LEFT]);
    rh = AVLCheck(jt->kids[JT_RIGHT]);
    JS_ASSERT(jt->balance == rh - lh);
    return 1 + JS_MAX(lh, rh);
}
#endif

static JSBool
SetSpanDepTarget(JSContext *cx, JSCodeGenerator *cg, JSSpanDep *sd,
                 ptrdiff_t off)
{
    AddJumpTargetArgs args;

    if (off < JUMPX_OFFSET_MIN || JUMPX_OFFSET_MAX < off) {
        ReportStatementTooLarge(cx, cg);
        return JS_FALSE;
    }

    args.cx = cx;
    args.cg = cg;
    args.offset = sd->top + off;
    args.node = NULL;
    AddJumpTarget(&args, &cg->jumpTargets);
    if (!args.node)
        return JS_FALSE;

#ifdef DEBUG_brendan
    AVLCheck(cg->jumpTargets);
#endif

    SD_SET_TARGET(sd, args.node);
    return JS_TRUE;
}

#define SPANDEPS_MIN            256
#define SPANDEPS_SIZE(n)        ((n) * sizeof(JSSpanDep))
#define SPANDEPS_SIZE_MIN       SPANDEPS_SIZE(SPANDEPS_MIN)

static JSBool
AddSpanDep(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc, jsbytecode *pc2,
           ptrdiff_t off)
{
    uintN index;
    JSSpanDep *sdbase, *sd;
    size_t size;

    index = cg->numSpanDeps;
    if (index + 1 == 0) {
        ReportStatementTooLarge(cx, cg);
        return JS_FALSE;
    }

    if ((index & (index - 1)) == 0 &&
        (!(sdbase = cg->spanDeps) || index >= SPANDEPS_MIN)) {
        if (!sdbase) {
            size = SPANDEPS_SIZE_MIN;
            JS_ARENA_ALLOCATE_CAST(sdbase, JSSpanDep *, &cx->tempPool, size);
        } else {
            size = SPANDEPS_SIZE(index);
            JS_ARENA_GROW_CAST(sdbase, JSSpanDep *, &cx->tempPool, size, size);
        }
        if (!sdbase)
            return JS_FALSE;
        cg->spanDeps = sdbase;
    }

    cg->numSpanDeps = index + 1;
    sd = cg->spanDeps + index;
    sd->top = PTRDIFF(pc, CG_BASE(cg), jsbytecode);
    sd->offset = sd->before = PTRDIFF(pc2, CG_BASE(cg), jsbytecode);

    if (js_CodeSpec[*pc].format & JOF_BACKPATCH) {
        /* Jump offset will be backpatched if off is a non-zero "bpdelta". */
        if (off != 0) {
            JS_ASSERT(off >= 1 + JUMP_OFFSET_LEN);
            if (off > BPDELTA_MAX) {
                ReportStatementTooLarge(cx, cg);
                return JS_FALSE;
            }
        }
        SD_SET_BPDELTA(sd, off);
    } else if (off == 0) {
        /* Jump offset will be patched directly, without backpatch chaining. */
        SD_SET_TARGET(sd, NULL);
    } else {
        /* The jump offset in off is non-zero, therefore it's already known. */
        if (!SetSpanDepTarget(cx, cg, sd, off))
            return JS_FALSE;
    }

    if (index > SPANDEP_INDEX_MAX)
        index = SPANDEP_INDEX_HUGE;
    SET_SPANDEP_INDEX(pc2, index);
    return JS_TRUE;
}

static JSBool
BuildSpanDepTable(JSContext *cx, JSCodeGenerator *cg)
{
    jsbytecode *pc, *end;
    JSOp op;
    const JSCodeSpec *cs;
    ptrdiff_t len, off;

    pc = CG_BASE(cg) + cg->spanDepTodo;
    end = CG_NEXT(cg);
    while (pc < end) {
        op = (JSOp)*pc;
        cs = &js_CodeSpec[op];
        len = (ptrdiff_t)cs->length;

        switch (cs->format & JOF_TYPEMASK) {
          case JOF_JUMP:
            off = GET_JUMP_OFFSET(pc);
            if (!AddSpanDep(cx, cg, pc, pc, off))
                return JS_FALSE;
            break;

          case JOF_TABLESWITCH:
          {
            jsbytecode *pc2;
            jsint i, low, high;

            pc2 = pc;
            off = GET_JUMP_OFFSET(pc2);
            if (!AddSpanDep(cx, cg, pc, pc2, off))
                return JS_FALSE;
            pc2 += JUMP_OFFSET_LEN;
            low = GET_JUMP_OFFSET(pc2);
            pc2 += JUMP_OFFSET_LEN;
            high = GET_JUMP_OFFSET(pc2);
            pc2 += JUMP_OFFSET_LEN;
            for (i = low; i <= high; i++) {
                off = GET_JUMP_OFFSET(pc2);
                if (!AddSpanDep(cx, cg, pc, pc2, off))
                    return JS_FALSE;
                pc2 += JUMP_OFFSET_LEN;
            }
            len = 1 + pc2 - pc;
            break;
          }

          case JOF_LOOKUPSWITCH:
          {
            jsbytecode *pc2;
            jsint npairs;

            pc2 = pc;
            off = GET_JUMP_OFFSET(pc2);
            if (!AddSpanDep(cx, cg, pc, pc2, off))
                return JS_FALSE;
            pc2 += JUMP_OFFSET_LEN;
            npairs = (jsint) GET_ATOM_INDEX(pc2);
            pc2 += ATOM_INDEX_LEN;
            while (npairs) {
                pc2 += ATOM_INDEX_LEN;
                off = GET_JUMP_OFFSET(pc2);
                if (!AddSpanDep(cx, cg, pc, pc2, off))
                    return JS_FALSE;
                pc2 += JUMP_OFFSET_LEN;
                npairs--;
            }
            len = 1 + pc2 - pc;
            break;
          }
        }

        JS_ASSERT(len > 0);
        pc += len;
    }

    return JS_TRUE;
}

static JSSpanDep *
GetSpanDep(JSCodeGenerator *cg, jsbytecode *pc)
{
    uintN index;
    ptrdiff_t offset;
    int lo, hi, mid;
    JSSpanDep *sd;

    index = GET_SPANDEP_INDEX(pc);
    if (index != SPANDEP_INDEX_HUGE)
        return cg->spanDeps + index;

    offset = PTRDIFF(pc, CG_BASE(cg), jsbytecode);
    lo = 0;
    hi = cg->numSpanDeps - 1;
    while (lo <= hi) {
        mid = (lo + hi) / 2;
        sd = cg->spanDeps + mid;
        if (sd->before == offset)
            return sd;
        if (sd->before < offset)
            lo = mid + 1;
        else
            hi = mid - 1;
    }

    JS_ASSERT(0);
    return NULL;
}

static JSBool
SetBackPatchDelta(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc,
                  ptrdiff_t delta)
{
    JSSpanDep *sd;

    JS_ASSERT(delta >= 1 + JUMP_OFFSET_LEN);
    if (!cg->spanDeps && delta < JUMP_OFFSET_MAX) {
        SET_JUMP_OFFSET(pc, delta);
        return JS_TRUE;
    }

    if (delta > BPDELTA_MAX) {
        ReportStatementTooLarge(cx, cg);
        return JS_FALSE;
    }

    if (!cg->spanDeps && !BuildSpanDepTable(cx, cg))
        return JS_FALSE;

    sd = GetSpanDep(cg, pc);
    JS_ASSERT(SD_GET_BPDELTA(sd) == 0);
    SD_SET_BPDELTA(sd, delta);
    return JS_TRUE;
}

static void
UpdateJumpTargets(JSJumpTarget *jt, ptrdiff_t pivot, ptrdiff_t delta)
{
    if (jt->offset > pivot) {
        jt->offset += delta;
        if (jt->kids[JT_LEFT])
            UpdateJumpTargets(jt->kids[JT_LEFT], pivot, delta);
    }
    if (jt->kids[JT_RIGHT])
        UpdateJumpTargets(jt->kids[JT_RIGHT], pivot, delta);
}

static JSSpanDep *
FindNearestSpanDep(JSCodeGenerator *cg, ptrdiff_t offset, int lo,
                   JSSpanDep *guard)
{
    int num, hi, mid;
    JSSpanDep *sdbase, *sd;

    num = cg->numSpanDeps;
    JS_ASSERT(num > 0);
    hi = num - 1;
    sdbase = cg->spanDeps;
    while (lo <= hi) {
        mid = (lo + hi) / 2;
        sd = sdbase + mid;
        if (sd->before == offset)
            return sd;
        if (sd->before < offset)
            lo = mid + 1;
        else
            hi = mid - 1;
    }
    if (lo == num)
        return guard;
    sd = sdbase + lo;
    JS_ASSERT(sd->before >= offset && (lo == 0 || sd[-1].before < offset));
    return sd;
}

static void
FreeJumpTargets(JSCodeGenerator *cg, JSJumpTarget *jt)
{
    if (jt->kids[JT_LEFT])
        FreeJumpTargets(cg, jt->kids[JT_LEFT]);
    if (jt->kids[JT_RIGHT])
        FreeJumpTargets(cg, jt->kids[JT_RIGHT]);
    jt->kids[JT_LEFT] = cg->jtFreeList;
    cg->jtFreeList = jt;
}

static JSBool
OptimizeSpanDeps(JSContext *cx, JSCodeGenerator *cg)
{
    jsbytecode *pc, *oldpc, *base, *limit, *next;
    JSSpanDep *sd, *sd2, *sdbase, *sdlimit, *sdtop, guard;
    ptrdiff_t offset, growth, delta, top, pivot, span, length, target;
    JSBool done;
    JSOp op;
    uint32 type;
    size_t size, incr;
    jssrcnote *sn, *snlimit;
    JSSrcNoteSpec *spec;
    uintN i, n, noteIndex;
    JSTryNote *tn, *tnlimit;
#ifdef DEBUG_brendan
    int passes = 0;
#endif

    base = CG_BASE(cg);
    sdbase = cg->spanDeps;
    sdlimit = sdbase + cg->numSpanDeps;
    offset = CG_OFFSET(cg);
    growth = 0;

    do {
        done = JS_TRUE;
        delta = 0;
        top = pivot = -1;
        sdtop = NULL;
        pc = NULL;
        op = JSOP_NOP;
        type = 0;
#ifdef DEBUG_brendan
        passes++;
#endif