[OpenJDK 2D-Dev] RFR: 8074843: Resolve disabled warnings for libmlib_image and libmlib_image_v

[Vadim Pakhnushev]

On 29.07.2016 16:28, Philip Race wrote:
>
>
> On 7/29/16, 3:23 AM, Vadim Pakhnushev wrote:
>> Phil,
>>
>> I guess you wanted to remove the lines in the Awt2dLibraries.gmk?
>
> Ah, yes. Not just disable them
>>
>> Do you think it's worth it to rewrite these assignments as separate 
>> assignment and a condition?
>> Especially long ones with a lot of parentheses?
>> Like this one, instead of
>> if ((j = ((mlib_s32) ((mlib_addr) psrc_row & 4) >> 2))) {
>>
>> j = (mlib_s32) ((mlib_addr) psrc_row & 4) >> 2;
>> if (j != 0) {
>
> I don't know. Where would I stop ?

Where it doesn't feel weird anymore?
For example, is this line correct?
       if (j = (((mlib_addr) pdst_row & 2) != 0)) {
It seems very weird for me that we assign a boolean value to the loop 
variable.
It looks like there's an error in parentheses and it should instead look 
like:
       if ((j = (((mlib_addr) pdst_row & 2) != 0) {
Yeah, in this particular case it doesn't even matter but still 
assignments in conditions can very easily lead to errors.

>
>>
>> Also seeing macro calls without a semicolon is weird.
>> I don't see any need in parentheses in the definition of 
>> FREE_AND_RETURN_STATUS so maybe it's possible to rewrite it without 
>> trailing semicolon?
>
> I anticipated the question and it is already addressed in my last
> paragraph right at the very bottom of the review request.

Oops, missed that.

> Basically that pattern has an "if (x==NULL) return". If you don't
> have that "if" then the compiler would have objected to that too !

I'm not sure I undestand this.

I mean why not rewrite the macro like this:
#define FREE_AND_RETURN_STATUS \
if (pbuff != buff) mlib_free(pbuff); \
if (k != akernel) mlib_free(k); \
return status
#endif /* FREE_AND_RETURN_STATUS */

Yes it's prone to errors like if (foo) FREE_AND_RETURN_STATUS; but all 
its usages are separate statements.

Vadim

>>
>> Thanks,
>> Vadim
>>
>> On 29.07.2016 2:31, Philip Race wrote:
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8074843
>>> Fix: http://cr.openjdk.java.net/~prr/8074843/
>>>
>>> Here's a sampling of the warnings that I think covers most, maybe 
>>> all, of the cases
>>> LINUX
>>> mlib_ImageAffine_NN_Bit.c:87:81: error: suggest parentheses around 
>>> '-' in operand of '&' [-Werror=parentheses]
>>>          res = (res & ~(1 << bit)) | (((srcPixelPtr[X >> (MLIB_SHIFT 
>>> + 3)] >> (7 - (X >> MLIB_SHIFT) & 7)) & 1) <<
>>> ^
>>> mlib_ImageAffine_NN_Bit.c:153:81: error: suggest parentheses around 
>>> '-' in operand of '&' [-Werror=parentheses]
>>>          res = (res & ~(1 << bit)) | (((srcPixelPtr[X >> (MLIB_SHIFT 
>>> + 3)] >> (7 - (X >> MLIB_SHIFT) & 7)) & 1) << bit);
>>>
>>> -----------------
>>> mlib_c_ImageCopy.c: In function 'mlib_c_ImageCopy_s16':
>>> mlib_c_ImageCopy.c:439:5: error: suggest parentheses around 
>>> assignment used as truth value [-Werror=parentheses]
>>>      STRIP(pdst, psrc, src_width, src_height, mlib_u16);
>>>      ^
>>> -
>>> MAC ...
>>>
>>> mlib_c_ImageCopy.c:331:5: error: using the result of an assignment 
>>> as a condition without parentheses [-Werror,-Wparentheses]
>>>     STRIP(pdst, psrc, src_width, src_height, mlib_u8);
>>>     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> mlib_c_ImageCopy.c:185:11: note: expanded from macro 'STRIP'
>>>     if (j = w & 1)                                              \
>>>         ~~^~~~~~~
>>> mlib_c_ImageCopy.c:331:5: note: place parentheses around the 
>>> assignment to silence this warning\
>>>
>>> ---
>>>
>>>
>>> ---
>>> SOLARIS
>>> mlib_ImageConv_16ext.c", line 532: statement not reached 
>>> (E_STATEMENT_NOT_REACHED)
>>>
>>> This last one was not nice just the ";" was considered a statement
>>> after the {XX; YY; return Z} macro expansion
>>> and turning into "do { {....} } while (0)" did not  help since
>>> then it said "loop terminator not reached - other cases we have
>>> like this have at least a condition in the macro.
>>>
>>> -phil.
>>

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