[Bug c++/57758] New: gcc accepts incorrect in-class brace initializers

[Bug c++/57758] New: gcc accepts incorrect in-class brace initializers

[lundberj at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57758

            Bug ID: 57758
           Summary: gcc accepts incorrect in-class brace initializers
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lundberj at gmail dot com

In summary, having a class member in-class copy-construct from itself (!)
compiles without warning when curly-brace syntax is used.

The result is that the class invariants are never established. The following
code is accepted: 

#include <iostream>
struct C{
   C()=delete;
   C(const C& other): x(other.x+1){}
   int x=10;
};
struct D{
   C c0{c0};  // << -- compiles without warning
 //C c1{c1};  // << -- correctly rejected
};
int main(){
   D d;
   std::cout << d.c0.x << std::endl; // prints 1
}

You already get the point. Similarly, these definitions of C also compiles, and
the printed value of x is 0 in both cases.

struct C{
   int x=10;  
   C(float,float){}
};
struct C{
   int x=10;  
};

Using the following definition I get an un-initialized reference: x == 1412476
:

struct C{
   C(const C& other): z(other.z),x(other.x){}
   int z=10;
   int & x{z};
};

This seems like something that would be good to detect.

Using class C{}; is correctly rejected (with 'too many initializers for ‘C’').
>From gcc-bugs-return-425438-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Sat Jun 29 19:32:47 2013
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From: "mikpe at it dot uu.se" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/57719] [4.8/4.9 Regression] wrong code at -O3 on x86_64-linux-gnu
Date: Sat, 29 Jun 2013 19:32:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idW719

--- Comment #4 from Mikael Pettersson <mikpe at it dot uu.se> ---
(In reply to Zhendong Su from comment #2)
> test #3: wrong code from gcc trunk (but not gcc 4.8) at -O3 in 32-bit mode
> only:

The wrong-code for test #3 started with r198121.

[Bug c++/57758] gcc accepts incorrect in-class brace initializers

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57758

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
                 CC|                            |paolo.carlini at oracle dot com

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Frankly, I doubt this issue adds new information beyond what we have got
already in Bugzilla, eg PR52167 & co.

[Bug c++/57758] gcc accepts incorrect in-class brace initializers

[lundberj at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57758

--- Comment #2 from Johan Lundberg <lundberj at gmail dot com> ---
Yes. I'm sorry, it's almost word-for-word identical to 48483.

[Bug c++/57758] gcc accepts incorrect in-class brace initializers

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57758

Paolo Carlini <paolo.carlini at oracle dot com> changed:

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

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Dup then.

*** This bug has been marked as a duplicate of bug 48483 ***