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?
Author: nathan Date: Wed Sep 14 14:29:01 2016 New Revision: 240136 URL: https://gcc.gnu.org/viewcvs?rev=240136&root=gcc&view=rev Log: cp/ PR c++/77539 * constexpr.c (get_fundef_copy): Use the original function for non-recursive evaluations. (save_fundef_copy): Always expect a slot to be available. testsuite/ PR c++/77539 * g++.dg/cpp0x/constexpr-recursion3.C: New. * g++.dg/ubsan/pr63956.C: Adjust error location. * g++.dg/cpp1y/pr77539.C: New. Added: branches/gcc-6-branch/gcc/testsuite/g++.dg/cpp0x/constexpr-recursion3.C branches/gcc-6-branch/gcc/testsuite/g++.dg/cpp1y/pr77539.C Modified: branches/gcc-6-branch/gcc/cp/ChangeLog branches/gcc-6-branch/gcc/cp/constexpr.c branches/gcc-6-branch/gcc/testsuite/ChangeLog branches/gcc-6-branch/gcc/testsuite/g++.dg/ubsan/pr63956.C
Author: nathan Date: Wed Sep 14 16:13:52 2016 New Revision: 240138 URL: https://gcc.gnu.org/viewcvs?rev=240138&root=gcc&view=rev Log: PR c++/77539 * g++.dg/cpp1y/pr77539.C: New. Added: trunk/gcc/testsuite/g++.dg/cpp1y/pr77539.C Modified: trunk/gcc/testsuite/ChangeLog
Patch backported, new testcase applied to trunk as well.