https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65620
Bug ID: 65620
Summary: Incorrect warning for !! with
-Wlogical-not-parentheses
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: andi-gcc at firstfloor dot org
Created attachment 35172
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35172&action=edit
test case
When building the linux 4.0-rc5 kernel with 5.0 there are several imho
bogus warnings like
warning: logical not is only applied to the left hand side of comparison
[-Wlogical-not-parentheses]
for constructs like this:
!!test_bit(...) != ...
The warning shouldn't warn for !! which is reasonably common. Looking at the
c/cp parsers there is already code to check for this, but it doesn't seem to
work here.
In the kernel case test_bit actually expands to a complex macro like
if (usage->type == 0x01 && !!(__builtin_constant_p((usage->code)) ?
constant_test_bit((usage->code), (input->key)) :
variable_test_bit((usage->key),
(input->key)))
I'm attaching an (already delta'ed but still quite big) test case
C++ likely has the same problem (but not tested)
