[Bug c++/64547] New: A non-const constexpr function is rejected incorrectly

[Bug c++/64547] New: A non-const constexpr function is rejected incorrectly

[ville.voutilainen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64547

            Bug ID: 64547
           Summary: A non-const constexpr function is rejected incorrectly
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ville.voutilainen at gmail dot com
                CC: jason at redhat dot com

struct X 
{
    int x; 
    constexpr int get() const {return x;} 
    constexpr void set(int foo) {x = foo;}
}; 

constexpr int bar() 
{
    X x{42}; 
    x.set(666); 
    return x.get();
} 

int main() 
{
    constexpr int foo = bar();
}

Clang accepts the code, gcc rejects with 

constexpr-member.cpp: In function ‘int main()’:
constexpr-member.cpp:17:28:   in constexpr expansion of ‘bar()’
constexpr-member.cpp:11:10:   in constexpr expansion of ‘x.X::set(666)’
constexpr-member.cpp:17:29: error: constexpr call flows off the end of the
function
     constexpr int foo = bar();
>From gcc-bugs-return-472549-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Jan 09 05:37:37 2015
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From: "ville.voutilainen at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/62277] [C++11] constexpr member methods are treated as const, regardless of const modifier
Date: Fri, 09 Jan 2015 05:37:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idb277

Ville Voutilainen <ville.voutilainen at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ville.voutilainen at gmail dot com

--- Comment #2 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
For what it's worth, now that C++14 relaxed constexpr rules are implemented,
the test snippet compiles fine.

[Bug c++/64547] A non-const constexpr function is rejected incorrectly

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64547

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-01-09
                 CC|                            |jason at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org
     Ever confirmed|0                           |1

[Bug c++/64547] A non-const constexpr function is rejected incorrectly

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64547

--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Mon Jan 12 14:15:07 2015
New Revision: 219466

URL: https://gcc.gnu.org/viewcvs?rev=219466&root=gcc&view=rev
Log:
    PR c++/64547
    * constexpr.c (cxx_eval_call_expression): A call to a void
    function doesn't need to return a value.

Added:
    trunk/gcc/testsuite/g++.dg/cpp1y/constexpr-void2.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/constexpr.c

[Bug c++/64547] A non-const constexpr function is rejected incorrectly

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64547

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed.