https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77539
Bug ID: 77539
Summary: gcc-5/6: comparison to nullptr failure in constexpr
(fixed by r235506 on trunk)
Product: gcc
Version: 6.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: trippels at gcc dot gnu.org
CC: nathan at gcc dot gnu.org
Target Milestone: ---
In
http://stackoverflow.com/questions/39405241/constexpr-comparision-to-nullptr-bug-or-feature/
a user posted the following testcase:
trippels@gcc2-power8 ~ % cat const2.ii
constexpr int foobar()
{
int array[100] = {};
int *ar = array;
if (ar == nullptr) // Error...
{
return 0;
}
return 1;
}
static_assert(foobar(),"");
trippels@gcc2-power8 ~ % ~/gcc_6/usr/local/bin/g++ -c const2.ii
const2.ii:12:1: error: non-constant condition for static assertion
static_assert(foobar(),"");
^~~~~~~~~~~~~
const2.ii:12:21: in constexpr expansion of ‘foobar()’
const2.ii:5:10: error: ‘(((int*)(& array)) == 0u)’ is not a constant expression
if (ar == nullptr) // Error...
~~~^~~~~~~~~~
This was fixed on trunk by r235506.
Nathan, would could you please backport your fix to gcc-6 branch?
