On 09/21/16 21:03, Jason Merrill wrote:
> On Wed, Sep 21, 2016 at 11:43 AM, Bernd Edlinger
> <bernd.edlin...@hotmail.de> wrote:
>> On 09/21/16 17:00, Jason Merrill wrote:
>>> On 09/20/2016 02:40 PM, Bernd Edlinger wrote:
>>>> On 09/20/16 16:51, Jason Merrill wrote:
>>>>> On Tue, Sep 20, 2016 at 10:11 AM, Bernd Edlinger
>>>>> <bernd.edlin...@hotmail.de> wrote:
>>>>>> I think I will have to suppress the warning if the conditional is in
>>>>>> a macro somehow.
>>>>>
>>>>> from_macro_expansion_at will help with that.
>>>>>
>>>>> Though it seems to me that the issue here is more that (TARGET_FP16 ?
>>>>> 14 : 12) is not in a boolean context, it's in an integer context; only
>>>>> the outer ?: is in a boolean context.
>>>>>
>>>> + if (warn_int_in_bool_context
>>>> + && !from_macro_expansion_at (EXPR_LOCATION (expr)))
>>>>
>>>> But this seems to suppress all such warnings from an assert
>>>> macro too. Like for instance "assert(a?1:2)".
>>>>
>>>> Sure, we would not be interested in a ?: that is part of the assert
>>>> macro itself, but the expression that is evaluated by the macro should
>>>> be checked, but that is no longer done, because the macro parameter is
>>>> now also from the macro expansion. But it is initially from the
>>>> macro invocation point. Ideas?
>>>
>>> This should fix that, though I haven't run regression tests yet:
>>>
>>
>> Yes. I think that goes in the right direction,
>> but it does not work yet.
>>
>> #define XXX (a ? 2 : 3)
>>
>> if (XXX) // prints a warning, but it should not.
>
> Indeed, that was too simplistic. This patch adds a
> from_macro_definition_at test that ought to do what you want:
>
Yes, this works for me as well.
Here is an updated warning patch, using the new
from_macro_definition_at.
Bernd.
2016-09-21 Bernd Edlinger <bernd.edlin...@hotmail.de>
* c-common.c (c_common_truthvalue_conversion): Inhibit
Wint-in-bool-context warning with from_macro_definition_at.
Mention the expression will always evaluate to true.
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c (Revision 240313)
+++ gcc/c-family/c-common.c (Arbeitskopie)
@@ -4652,7 +4652,8 @@ c_common_truthvalue_conversion (location_t locatio
TREE_OPERAND (expr, 0));
case COND_EXPR:
- if (warn_int_in_bool_context)
+ if (warn_int_in_bool_context
+ && !from_macro_definition_at (EXPR_LOCATION (expr)))
{
tree val1 = fold_for_warn (TREE_OPERAND (expr, 1));
tree val2 = fold_for_warn (TREE_OPERAND (expr, 2));
@@ -4663,7 +4664,8 @@ c_common_truthvalue_conversion (location_t locatio
&& (!integer_onep (val1)
|| !integer_onep (val2)))
warning_at (EXPR_LOCATION (expr), OPT_Wint_in_bool_context,
- "?: using integer constants in boolean context");
+ "?: using integer constants in boolean context, "
+ "the expression will always evaluate to %<true%>");
}
/* Distribute the conversion into the arms of a COND_EXPR. */
if (c_dialect_cxx ())
