On Fri, Dec 27, 2013 at 10:54 PM, Trevor Saunders wrote:
> On Mon, Dec 23, 2013 at 09:26:41AM -0500, Prathamesh Kulkarni wrote:
>> IS_EXPR_CODE_CLASS() is called at 18 places within gcc subdirectory,
>> and except for expr_check(), tree_block(), tree_set_block() all the
>> other callers pass argument of type enum tree_code_class to
>> IS_EXPR_CODE_CLASS().
>>
>> These four callers (expr_check is overloaded) assign value of
>> TREE_CODE_CLASS() to variable of type char const, and then pass it as
>> argument to IS_EXPR_CODE_CLASS()
>
> that sounds like a bug, or at least a aimed and loaded foot gun
>
>> For example: tree_block():
>> tree
>> tree_block (tree t)
>> {
>> char const c = TREE_CODE_CLASS (TREE_CODE (t));
>>
>> if (IS_EXPR_CODE_CLASS (c))
>> return LOCATION_BLOCK (t->exp.locus);
>> gcc_unreachable ();
>> return NULL;
>> }
>>
>> Should type of "c" be changed to const enum tree_code_class instead
>> (similarly in other callers) ? Also, TREE_CODE_CLASS()'s value is of
>> type enum tree_code_class.
>
> Well, in that case using a local variable seems pretty useless, why not
> just get rid of it? However switching the type certainly seems
> reasonable.
In some callers (eg: iterative_hash_expr()), the local variable is
used multiple times.
Getting rid of it, when it's only used once is better.
>
> Trev
>
>>
>> This gave a compile-error: invalid conversion from ‘char’ to
>> ‘tree_code_class’
>> when i changed the macro IS_EXPR_CODE_CLASS() to the following function:
>>
>> static inline bool
>> IS_EXPR_CODE_CLASS(enum tree_code_class code_class)
>> {
>> return (code_class >= tcc_reference) && (code_class <= tcc_expression);
>> }
>>
>> Thanks and Regards,
>> Prathamesh
