<AWT Dev> [9] Review request: new macro for conversion to jboolean

[Mike Duigou]

What if we just abandon adding an IS_TRUE / TO_JBOOLEAN macro for now.

I would like to address adding (jboolean) casts to jni.h which I suspect would help with the static analysis issues encountered.

For now just use the explicit ? JNI_TRUE : JNI_FALSE whenever a jboolean value is needed and we can refactor the naming of the macro, if any is required, later.

Mike

On Mar 21 2014, at 08:10 , roger riggs <roger.riggs at oracle.com> wrote:

> Hi Sergey,
> 
> I didn't see any examples of the use case in this thread.  The proposed name seems bulky and clumsy.
> 
> In the snippet provided, it did not seem necessary to force the cast to jboolean.
> Both JNI_TRUE and JNI_FALSE are untyped constants.
> 
> The macro would just as useful (if I understand the cases) without the cast.
> 
> How useful is a simple definition as:
> 
> #define IS_TRUE(obj) ((obj) ? JNI_TRUE : JNI_FALSE)
> 
> then it would look ok to see these in sources:
> 
>      return IS_TRUE(obj);
> 
>      if (IS_TRUE(obj)) {....}
> 
>      jboolean ret = IS_TRUE(obj);
> 
> The general purpose usage matches the general C conventions for
> true and false and match the JNI semantics.
> 
> Roger
> 
> 
> 
> On 3/19/2014 7:43 PM, Sergey Bylokhov wrote:
>> Thanks.
>> So if nobody objects, the final version will be:
>> 
>> #define IS_NULL(obj) ((obj) == NULL)
>> #define JNU_IsNull(env,obj) ((obj) == NULL)
>> +#define TO_JBOOLEAN(obj) (jboolean) ((obj) ? JNI_TRUE : JNI_FALSE)
>> 
>> 
>> On 3/20/14 12:07 AM, roger riggs wrote:
>>> Hi,
>>> 
>>> Well...  When JNU_RETURN was added, there was a long discussion about
>>> NOT using JNU unless the JNI environment was an argument to the macro.
>>> 
>>> So, the simple name is preferred.
>>> 
>>> Roger
>>> 
>>> On 3/19/2014 4:08 PM, Phil Race wrote:
>>>> PS .. so maybe whilst you are touching this file you could do
>>>> #define JNU_CHECK_NULL CHECK_NULL
>>>> #define JNU_CHECK_NULL_RETURN CHECK_NULL_RETURN
>>>> 
>>>> so we could migrate to these (clearer) ones
>>>> 
>>>> -phil.
>>>> 
>>>> On 3/19/2014 1:05 PM, Phil Race wrote:
>>>>> I think having it start with "JNU_" is a good suggestion.
>>>>> I've been wondering over the last week or so if it would not have been
>>>>> better to have CHECK_NULL called JNU_CHECK_NULL to reduce collision chances
>>>>> and to make it clearer where it comes from ..
>>>>> 
>>>>> -phil.
>>>>> 
>>>>> On 3/19/2014 12:49 PM, Mike Duigou wrote:
>>>>>> Definitely a useful macro.
>>>>>> 
>>>>>> I too would prefer a name like TO_JBOOLEAN since it reveals the result type. Also all uppercase to identify it as a macro. If we are paranoid and want to reduce the chance of a name collision then JNU_TO_JBOOLEAN perhaps.
>>>>>> 
>>>>>> I would also define the macro as:
>>>>>> 
>>>>>> #define JNU_TO_JBOOLEAN(obj) (jboolean) ((obj) ? JNI_TRUE : JNI_FALSE)
>>>>>> 
>>>>>> so that the type of the result is explicit. Unfortunately jni.h doesn't define JNI_TRUE or false with a cast to jboolean as they probably should.
>>>>>> 
>>>>>> Mike
>>>>>> 
>>>>>> On Mar 19 2014, at 11:36 , Sergey Bylokhov <sergey.bylokhov at oracle.com> wrote:
>>>>>> 
>>>>>>> Thanks Anthony!
>>>>>>> 
>>>>>>> Can somebody from the core-libs team take a look?
>>>>>>> 
>>>>>>> On 3/17/14 10:31 PM, Anthony Petrov wrote:
>>>>>>>> Personally, I'd call it to_jboolean(obj), but IS_TRUE(obj) sounds good to me too. Either way, I'm fine with the fix.
>>>>>>>> 
>>>>>>>> -- 
>>>>>>>> best regards,
>>>>>>>> Anthony
>>>>>>>> 
>>>>>>>> On 3/17/2014 7:01 PM, Sergey Bylokhov wrote:
>>>>>>>>> Hello.
>>>>>>>>> This review request is for the new macro, which simplify conversion to
>>>>>>>>> jboolean. It will be useful for fixing parfait warnings.
>>>>>>>>> 
>>>>>>>>> We have a lot of places, where we cast some type to jboolean:
>>>>>>>>> 
>>>>>>>>> BOOL = retVal;
>>>>>>>>> return (jboolean) retVal;
>>>>>>>>> 
>>>>>>>>> WARNING: Expecting value of JNI primitive type jboolean: mismatched
>>>>>>>>> value retVal with size 32 bits, retVal used for conversion to int8 in return
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> +++ b/src/share/native/common/jni_util.h    Mon Mar 17 18:28:48 2014 +0400
>>>>>>>>> @@ -277,6 +277,7 @@
>>>>>>>>> 
>>>>>>>>>  #define IS_NULL(obj) ((obj) == NULL)
>>>>>>>>>  #define JNU_IsNull(env,obj) ((obj) == NULL)
>>>>>>>>> +#define IS_TRUE(obj) ((obj) ? JNI_TRUE : JNI_FALSE)
>>>>>>>>> 
>>>>>>>>> I am not sure about the name, probably someone have a better suggestion?
>>>>>>>>> 
>>>>>>>>> The fix is for jdk9/dev.
>>>>>>>>> 
>>>>>>>>> -- 
>>>>>>>>> Best regards, Sergey.
>>>>>>>>> 
>>>>>>> 
>>>>>>> -- 
>>>>>>> Best regards, Sergey.
>>>>>>> 
>>>>> 
>>>> 
>>> 
>> 
>> 
>