[PATCH v3 1/2] jscript: implement Enumerator()

Jacek Caban jacek at codeweavers.com
Thu May 9 08:27:55 CDT 2019


Hi Andreas,


It's mostly looking good, but some details still need a bit more work.


On 5/6/19 10:21 PM, Andreas Maier wrote:
> Signed-off-by: Andreas Maier <staubim at quantentunnel.de>
> ---
>   dlls/jscript/enumerator.c | 227 +++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 216 insertions(+), 11 deletions(-)
>
> diff --git a/dlls/jscript/enumerator.c b/dlls/jscript/enumerator.c
> index aa7737ac52..a7cad81c8a 100644
> --- a/dlls/jscript/enumerator.c
> +++ b/dlls/jscript/enumerator.c
> @@ -26,6 +26,11 @@ WINE_DEFAULT_DEBUG_CHANNEL(jscript);
>
>   typedef struct {
>       jsdisp_t dispex;
> +    BOOL atend;
> +    /* IEnumVARIANT returned by _NewEnum */
> +    IEnumVARIANT *enumvar;
> +    /* IEnumVARIANT current item */
> +    VARIANT* enumitm;


There is no need to allocate enumitm (BTW, maybe call it just 'item'?) 
separately. You could just store the structure inside 
EnumeratorInstance. I would also suggest storing it as jsval_t. If you 
just set it to jsval_undefined() when you're at the end, it could 
simplify things even more.


>   } EnumeratorInstance;
>
>   static const WCHAR atEndW[] = {'a','t','E','n','d',0};
> @@ -33,43 +38,156 @@ static const WCHAR itemW[] = {'i','t','e','m',0};
>   static const WCHAR moveFirstW[] = {'m','o','v','e','F','i','r','s','t',0};
>   static const WCHAR moveNextW[] = {'m','o','v','e','N','e','x','t',0};
>
> +static inline EnumeratorInstance *enumerator_from_jsdisp(jsdisp_t *jsdisp)
> +{
> +    return CONTAINING_RECORD(jsdisp, EnumeratorInstance, dispex);
> +}
> +
> +static inline EnumeratorInstance *enumerator_from_vdisp(vdisp_t *vdisp)
> +{
> +    return enumerator_from_jsdisp(vdisp->u.jsdisp);
> +}
> +
> +static inline HRESULT enumvar_get_next_item(
> +    IEnumVARIANT* enumvar, VARIANT* enumitm,
> +    BOOL* atend, jsval_t *r)


I expect that passing EnumeratorInstance pointer instead of its fields 
separately would make things easier.


> +{
> +    HRESULT hres;
> +
> +    /* not at end ... get next item */
> +    if (!(*atend))
> +    {
> +        /* Assume valid variant */
> +        VariantClear(enumitm);
> +        hres = IEnumVARIANT_Next(enumvar, 1, enumitm, NULL);
> +        if (hres != S_OK)
> +        {
> +            VariantClear(enumitm);
> +            *atend = TRUE;
> +        }
> +    }
> +
> +    if (*atend)
> +    {
> +        if (r)
> +            *r = jsval_undefined();
> +        return S_OK;
> +    }
> +
> +    if (r)
> +        return variant_to_jsval(enumitm, r);
> +
> +    return S_OK;
> +}
> +
>   static void Enumerator_destructor(jsdisp_t *dispex)
>   {
> +    EnumeratorInstance *This;
> +
>       TRACE("Enumerator_destructor\n");
>
> +    This = enumerator_from_jsdisp(dispex);
> +
> +    if (This->enumitm)
> +    {
> +        VariantClear(This->enumitm);
> +        heap_free(This->enumitm);
> +    }
> +
>       heap_free(dispex);
>   }
>
>   HRESULT Enumerator_atEnd(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv,
>           jsval_t *r)
>   {
> -    TRACE("Enumerator_atEnd\n");
> +    EnumeratorInstance *This;
> +
> +    This = enumerator_from_vdisp(jsthis);
>
> -    return E_NOTIMPL;
> +    if (r)
> +        *r = jsval_bool(This->atend);
> +
> +    TRACE("Enumerator_atEnd %d\n", This->atend);


I missed it in already committed patch, but please don't add function 
names to debug traces. Wine will add it for you.


> +
> +    return S_OK;
>   }
>
>   HRESULT Enumerator_item(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv,
>           jsval_t *r)
>   {
> +    EnumeratorInstance *This;
> +    HRESULT hres = E_FAIL;
> +
>       TRACE("Enumerator_item\n");
>
> -    return E_NOTIMPL;
> +    This = enumerator_from_vdisp(jsthis);


You need to make sure that This is actually an enumerator instance. 
JavaScript allows passing arbitrary values as this with something like 
Enumerator.prototype.item.call(new Object());


See how it's handled in bool.c for an example (and don't worry about 
exact error exceptions, FIXME(); return E_NOTIMPL; is fine for the first 
iteration). Same applies to other functions.


> +
> +    if (This->enumvar)
> +    {
> +        hres = variant_to_jsval(This->enumitm, r);
> +    }
> +    else
> +    {
> +        if (r)
> +            *r = jsval_undefined();
> +        hres = S_OK;
> +    }
> +
> +    return hres;


If you store the value as I suggested, it could be just:

return r ? jsval_copy(This->item, r) : S_OK;


>   }
>
>   HRESULT Enumerator_moveFirst(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv,
>           jsval_t *r)
>   {
> +    EnumeratorInstance *This;
> +    HRESULT hres = E_FAIL;
> +
>       TRACE("Enumerator_moveFirst\n");
>
> -    return E_NOTIMPL;
> +    This = enumerator_from_vdisp(jsthis);
> +    if (This->enumvar)
> +    {
> +        IEnumVARIANT_Reset(This->enumvar);


We should probably check for Reset() error.


> +        hres = enumvar_get_next_item(This->enumvar, This->enumitm, &This->atend, r);


Does it really return the item value here? It would need a test, but I'd 
expect it to return undefined value.


> +    }
> +    else
> +    {
> +        if (r)
> +            *r = jsval_undefined();
> +        hres = S_OK;
> +    }
> +
> +    return hres;
>   }
>
>   HRESULT Enumerator_moveNext(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv,
>           jsval_t *r)
>   {
> +    EnumeratorInstance *This;
> +    HRESULT hres = E_FAIL;
> +
>       TRACE("Enumerator_moveNext\n");
>
> -    return E_NOTIMPL;
> +    This = enumerator_from_vdisp(jsthis);
> +
> +    if (This->atend)
> +    {
> +        if (r)
> +            *r = jsval_undefined();
> +        return S_OK;
> +    }
> +    if (This->enumvar)
> +    {
> +        hres = enumvar_get_next_item(This->enumvar, This->enumitm, &This->atend, r);


Same here, should it return the value?


> @@ -180,11 +301,95 @@ HRESULT create_enumerator(script_ctx_t *ctx, jsval_t *argv, jsdisp_t **ret)
>   {
>       EnumeratorInstance *enumerator;
>       HRESULT hres;
> +    IDispatch *obj;
> +    DISPPARAMS dispparams = {NULL, NULL, 0, 0};
> +    VARIANT varresult;
> +
> +    BOOL atend = TRUE;
> +    IEnumVARIANT *enumvar = NULL;
> +    VARIANT *enumitm = NULL;
> +
> +    memset(&varresult, 0, sizeof(VARIANT));
> +    VariantInit(&varresult);
> +
> +    /* new Enumerator() */
> +    if (argv == NULL)
> +    {
> +        atend = TRUE;
> +    }
> +    else if(is_object_instance(*argv))
> +    {
> +        obj = get_object(*argv);
> +
> +        /* Try to get a IEnumVARIANT by _NewEnum */
> +        hres = IDispatch_Invoke(obj,
> +            DISPID_NEWENUM, &IID_NULL, LOCALE_NEUTRAL,
> +            DISPATCH_METHOD, &dispparams, &varresult,
> +            NULL, NULL);
> +        if (FAILED(hres))
> +        {
> +            ERR("Enumerator: no DISPID_NEWENUM.\n");
> +            hres = E_INVALIDARG;
> +            goto cleanuperr;
> +        }
> +
> +        if (V_VT(&varresult) == VT_DISPATCH)
> +        {
> +            hres = IUnknown_QueryInterface(V_DISPATCH(&varresult),
> +                &IID_IEnumVARIANT, (void**)&enumvar);
> +        }
> +        else if (V_VT(&varresult) == VT_UNKNOWN)
> +        {
> +            hres = IUnknown_QueryInterface(V_UNKNOWN(&varresult),
> +                &IID_IEnumVARIANT, (void**)&enumvar);
> +        }


Note that IDispatch inherits from IUnknown, so you could just handle 
them as a single case and use V_UNKNOWN.


Thanks,

Jacek




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