[PATCH] Add -Wabsolute-value

[Jeff Law]

On 9/4/18 3:08 AM, Martin Jambor wrote:
> Hi,
> 
> On Fri, Aug 31 2018, Joseph Myers wrote:
>> On Fri, 31 Aug 2018, Martin Jambor wrote:
>>
>>> diff --git a/gcc/common.opt b/gcc/common.opt
>>> index ebc3ef43ce2..2950760fb2a 100644
>>> --- a/gcc/common.opt
>>> +++ b/gcc/common.opt
>>> @@ -815,6 +815,10 @@ Wvector-operation-performance
>>>  Common Var(warn_vector_operation_performance) Warning
>>>  Warn when a vector operation is compiled outside the SIMD.
>>>  
>>> +Wabsolute-value
>>> +Common Var(warn_absolute_value) Warning EnabledBy(Wextra)
>>> +Warn on suspicious calls of standard functions computing absolute values.
>>
>> If it's C-specific I'd expect it to be in c.opt (in the appropriate 
>> alphabetical position) and have "C ObjC" instead of Common.
> 
> I see, fixed.
> 
>>
>>> +@item -Wabsolute-value
>>> +@opindex Wabsolute-value
>>> +@opindex Wno-absolute-value
>>> +Warn when a wrong absolute value function seems to be used or when it
>>> +does not have any effect because its argument is an unsigned type.
>>> +This warning is specific to C language and can be suppressed with an
>>> +explicit type cast.  This warning is also enabled by @option{-Wextra}.
>>
>> And then the @item would have @r{(C and Objective-C only)}, similar to 
>> other such options (rather than saying "specific to C language" in the 
>> text).
>>
> 
> Likewise.
> 
> I have bootstrapped and tested the updated (and re-based) patch on
> x86-64-linux.  OK for trunk now?
> 
> Thank you very much,
> 
> Martin
> 
> 
> 2018-09-03  Martin Jambor  <mjambor@suse.cz>
> 
> 	gcc/
> 	* doc/invoke.texi (Warning Options): Likewise.
> 
> 	gcc/c-family/
> 	* c.opt (Wabsolute-value): New.
> 
> 	gcc/c/
> 	* c-parser.c: (warn_for_abs): New function.
> 	(c_parser_postfix_expression_after_primary): Call it.
> 
> 	testsuite/
> 	* gcc.dg/warn-abs-1.c: New test.
> 	* gcc.dg/dfp/warn-abs-2.c: Likewise.
OK.
jeff