RFR: (8030875) Macros for checking and returning on exceptions

[Martin Buchholz]

On Tue, Jan 14, 2014 at 7:54 AM, roger riggs <roger.riggs at oracle.com> wrote:

> Hi David,
>
> The CHECK_RETURN macros have existed in java.net for some time and
> I have not seen any empty statement warnings.
>
> The CHECK_EXCEPTION macros are new and does not have any uses yet.
> I don't plan to do any wholesale modification of current sources.
>
> The macros always produce a valid statement;  (though my c/c++ may be a
> bit rusty).
>
>
Macros should not generally be complete statements, including semicolons;
then the source code looks like this:

FOO()

which looks (including to emacs) like someone forgot the trailing semicolon.

Instead, these macros should be written using the "well-known" do ( ... )
while (0) idiom, e.g.

#define CHECK_NULL(x) do { if ((x) == NULL) return; } while (0)


> (Note that it has been requested to rename the macros to include a
> JNU_prefix
> to be consistent with other macros in jni_util.h. I will propose a
> separate set of changes for that).
>
> Roger
>
>
> On 1/13/2014 9:51 PM, David Holmes wrote:
>
>> Hi Roger,
>>
>>
>>  webrev:
>>> http://cr.openjdk.java.net/~rriggs/webrev-check-exception-8030875/
>>>
>>
>> Do these macro definitions not cause "empty statement" warnings from the
>> compiler? (Existing ones have the same problem I guess)
>>
>> Also I don't see any use of the CHECK_EXCEPTION macros? In fact the bulk
>> of changes here seem completely unrelated to the "exception" aspect of this
>> CR.
>>
>> Cheers,
>> David
>>
>>  [1] https://bugs.openjdk.java.net/browse/JDK-8030875
>>>
>>
>