[Bug c++/103347] New: Non-static data member initialization is erroneously allowed in C++03 mode

[Bug c++/103347] New: Non-static data member initialization is erroneously allowed in C++03 mode

[fchelnokov at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

            Bug ID: 103347
           Summary: Non-static data member initialization is erroneously
                    allowed in C++03 mode
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fchelnokov at gmail dot com
  Target Milestone: ---

This code is invalid in C++03 mode:
```
#include <cstddef>
struct test {
    void *x = NULL; //invalid in C++03 mode
};
int main() {}
```
It is rejected by Clang, not not by GCC. Demo:
https://gcc.godbolt.org/z/113EWvzzx

Related discussion: https://stackoverflow.com/q/49618716/7325599

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is macro tracking which is getting in the way of emitting the warning as
NULL is from a system header, there is a dup of this bug already.

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
That is GCC does warning about the following case:
struct test {
    int x = 0;
};
int main() {}

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 77513

*** This bug has been marked as a duplicate of bug 77513 ***

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> That is GCC does warning about the following case:
> struct test {
>     int x = 0;
> };
> int main() {}

And you get an error with -pedantic-errors

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually this is a dup of bug 57201.

*** This bug has been marked as a duplicate of bug 57201 ***

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Let's mark this as a dup of bug 77299.

*** This bug has been marked as a duplicate of bug 77299 ***

[Bug c++/103347] Non-static data member initialization is erroneously allowed in C++03 mode

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|DUPLICATE                   |---
             Status|RESOLVED                    |NEW
   Last reconfirmed|                            |2021-11-22
     Ever confirmed|0                           |1

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually let's reopen this one too.
It might be a different bug from PR 77299  ...

[Bug c++/103347] [9/10/11/12 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |9.5

[Bug c++/103347] [9/10/11/12 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dmalcolm at gcc dot gnu.org,
                   |                            |jakub at gcc dot gnu.org,
                   |                            |jason at gcc dot gnu.org,
                   |                            |mpolacek at gcc dot gnu.org

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Perhaps a faster way to fix this would be to try to warn on the = token rather
than on input_location which happens to be the location of NULL after
cp_parser_cache_defarg went through it.
For
struct test {
    int x = 1 + 2; //invalid in C++03 mode
};
we strangely warn with caret on the 2, for int x = (1 + 2); with caret on )
etc.
maybe_warn_cpp0x doesn't really take a location_t though, probably it should.
And grokdeclarator isn't called with the actual initializer (DEFERRED_PARSE)
from which we could dig up the location of the first token.

[Bug c++/103347] [9/10/11/12 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org

--- Comment #9 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #8)
> And grokdeclarator isn't called with the actual initializer (DEFERRED_PARSE)
> from which we could dig up the location of the first token.

True, though cp_parser_member_declaration has initializer_token_start which
carries the location of the '='.  I suppose we could add another location_t to
cp_declarator for init-declarators, and then just use it.

For which I have a patch:

$ ./cc1plus -quiet 103347.C -std=c++03 
103347.C:3:13: warning: non-static data member initializers only available with
‘-std=c++11’ or ‘-std=gnu++11’ [-Wc++11-extensions]
    3 |     void *x = NULL; //invalid in C++03 mode
      |             ^

[Bug c++/103347] [9/10/11/12 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:d71d019f63ed5d3fdb34579023bafa4dcf323f2c

commit r12-5488-gd71d019f63ed5d3fdb34579023bafa4dcf323f2c
Author: Marek Polacek <polacek@redhat.com>
Date:   Mon Nov 22 14:09:25 2021 -0500

    c++: Fix missing NSDMI diagnostic in C++98 [PR103347]

    Here the problem is that we aren't detecting a NSDMI in C++98:

    struct A {
      void *x = NULL;
    };

    because maybe_warn_cpp0x uses input_location and that happens to point
    to NULL which comes from a system header.  Jakub suggested changing the
    location to the '=', thereby avoiding the system header problem.  To
    that end, I've added a new location_t member into cp_declarator.  This
    member is used when this declarator is part of an init-declarator.  The
    rest of the changes is obvious.  I've also taken the liberty of adding
    loc_or_input_loc, since I want to avoid checking for UNKNOWN_LOCATION.

            PR c++/103347

    gcc/cp/ChangeLog:

            * cp-tree.h (struct cp_declarator): Add a location_t member.
            (maybe_warn_cpp0x): Add a location_t parameter with a default
argument.
            (loc_or_input_loc): New.
            * decl.c (grokdeclarator): Use loc_or_input_loc.  Pass init_loc
down
            to maybe_warn_cpp0x.
            * error.c (maybe_warn_cpp0x): Add a location_t parameter.  Use it.
            * parser.c (make_declarator): Initialize init_loc.
            (cp_parser_member_declaration): Set init_loc.
            (cp_parser_condition): Likewise.
            (cp_parser_init_declarator): Likewise.
            (cp_parser_parameter_declaration): Likewise.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/nsdmi-warn1.C: New test.
            * g++.dg/cpp0x/nsdmi-warn1.h: New file.

[Bug c++/103347] [9/10/11 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
            Summary|[9/10/11/12 Regression]     |[9/10/11 Regression]
                   |Non-static data member      |Non-static data member
                   |initialization is           |initialization is
                   |erroneously allowed in      |erroneously allowed in
                   |C++03 with assignment to    |C++03 with assignment to
                   |NULL                        |NULL

--- Comment #11 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed in GCC 12.

[Bug c++/103347] [9/10/11 Regression] Non-static data member initialization is erroneously allowed in C++03 with assignment to NULL

[ensadc at mailnesia dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103347

ensadc at mailnesia dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ensadc at mailnesia dot com

--- Comment #12 from ensadc at mailnesia dot com ---
*** Bug 66839 has been marked as a duplicate of this bug. ***