[Bug c++/70194] New: [6 regression] missing -Waddress on constexpr pointer

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70194

            Bug ID: 70194
           Summary: [6 regression] missing -Waddress on constexpr pointer
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msebor at gcc dot gnu.org
  Target Milestone: ---

GCC 5 and prior issue a -Waddress warning for each of the equality expressions
in the test case below.  The current top of GCC 6.0 trunk doesn't diagnose the
second equality expression where the address being compared is stored in a
constexpr pointer.  

$ (set -x; cat v.c && ~/bin/gcc-5.1.0/bin/g++ -S -Wall -Wextra -Wpedantic
-o/dev/null -std=c++14 -xc++ v.c && /home/msebor/build/gcc-trunk-git/gcc/xgcc
-B/home/msebor/build/gcc-trunk-git/gcc -S -Wall -Wextra -Wpedantic -o/dev/null
-xc++ v.c)
+ cat v.c
int i;

const bool b0 = &i == 0;

constexpr int *p = &i;
const bool b1 = p == 0;
+ /home/msebor/bin/gcc-5.1.0/bin/g++ -S -Wall -Wextra -Wpedantic -o/dev/null
-std=c++14 -xc++ v.c
v.c:3:23: warning: the address of ‘i’ will never be NULL [-Waddress]
 const bool b0 = &i == 0;
                       ^
v.c:6:22: warning: the address of ‘i’ will never be NULL [-Waddress]
 const bool b1 = p == 0;
                      ^
+ /home/msebor/build/gcc-trunk-git/gcc/xgcc
-B/home/msebor/build/gcc-trunk-git/gcc -S -Wall -Wextra -Wpedantic -o/dev/null
-xc++ v.c
v.c:3:23: warning: the address of ‘i’ will never be NULL [-Waddress]
 const bool b0 = &i == 0;
                       ^