[Bug c++/100838] New: -fno-elide-constructors for C++14 missing required destructor call

[Bug c++/100838] New: -fno-elide-constructors for C++14 missing required destructor call

[kirshamir at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

            Bug ID: 100838
           Summary: -fno-elide-constructors for C++14 missing required
                    destructor call
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kirshamir at gmail dot com
  Target Milestone: ---

Code: https://godbolt.org/z/jKnKTds7s

#include <iostream>

class MyString {
public:
  MyString(const char* s = "") {
    std::cout << "ctor" << std::endl;
  }
  ~MyString() { 
    std::cout << "dtor" << std::endl;
  }
  MyString(const MyString& s) {
    std::cout << "copy ctor" << std::endl;
  }
  MyString& operator=(const MyString& s) {
    std::cout << "operator=" << std::endl;
    return *this;
  }
};

int main() {
  MyString s1 = "Hello";
  std::cout << __LINE__ << std::endl;
}

---------------
When compiled with:
-std=c++14 -fno-elide-constructors

Output:

ctor
copy ctor
22
dtor

Expected output:

ctor
copy ctor
dtor
22
dtor

[Bug c++/100838] -fno-elide-constructors for C++14 missing required destructor call

[kirshamir at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #1 from Amir Kirsh <kirshamir at gmail dot com> ---
This main:

int main() {
  MyString s1 = MyString{"Hello"}; // same also for rounded brackets 
  std::cout << __LINE__ << std::endl;
}

works as expected.

Output with C++14 and -fno-elide-constructors:

ctor
copy ctor
dtor
22
dtor

[Bug c++/100838] [11/12 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
            Summary|-fno-elide-constructors for |[11/12 Regression]
                   |C++14 missing required      |-fno-elide-constructors for
                   |destructor call             |C++14 missing required
                   |                            |destructor call since
                   |                            |r11-5872-g4eb28483004f8291
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-05-31
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-5872-g4eb28483004f8291.

[Bug c++/100838] [11/12 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

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

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

[Bug c++/100838] [11/12 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:63d182b29306e582bfb151cf762820211ea1cc7e

commit r12-1165-g63d182b29306e582bfb151cf762820211ea1cc7e
Author: Jason Merrill <jason@redhat.com>
Date:   Mon May 31 12:36:25 2021 -0400

    c++: missing dtor with -fno-elide-constructors [PR100838]

    tf_no_cleanup only applies to the outermost TARGET_EXPR, and we already
    clear it for nested calls in build_over_call, but in this case both
    constructor calls came from convert_like, so we need to clear it in the
    recursive call as well.  This revealed that we were adding an extra
    ck_rvalue in direct-initialization cases where it was wrong.

            PR c++/100838

    gcc/cp/ChangeLog:

            * call.c (convert_like_internal): Clear tf_no_cleanup when
            recursing.
            (build_user_type_conversion_1): Only add ck_rvalue if
            LOOKUP_ONLYCONVERTING.

    gcc/testsuite/ChangeLog:

            * g++.dg/init/no-elide2.C: New test.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11/12 Regression]          |[11 Regression]
                   |-fno-elide-constructors for |-fno-elide-constructors for
                   |C++14 missing required      |C++14 missing required
                   |destructor call since       |destructor call since
                   |r11-5872-g4eb28483004f8291  |r11-5872-g4eb28483004f8291

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 12 so far.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.2
           Priority|P3                          |P2
      Known to work|                            |12.0
      Known to fail|                            |11.1.0

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:5830fffacd05463c20b592bb6ed20e333d7d272b

commit r11-8715-g5830fffacd05463c20b592bb6ed20e333d7d272b
Author: Jason Merrill <jason@redhat.com>
Date:   Mon May 31 12:36:25 2021 -0400

    c++: missing dtor with -fno-elide-constructors [PR100838]

    tf_no_cleanup only applies to the outermost TARGET_EXPR, and we already
    clear it for nested calls in build_over_call, but in this case both
    constructor calls came from convert_like, so we need to clear it in the
    recursive call as well.  This revealed that we were adding an extra
    ck_rvalue in direct-initialization cases where it was wrong.

    For GCC 11, limit the changes to -fno-elide-constructors.

            PR c++/100838

    gcc/cp/ChangeLog:

            * call.c (convert_like_internal): Clear tf_no_cleanup when
            recursing.
            (build_user_type_conversion_1): Only add ck_rvalue if
            LOOKUP_ONLYCONVERTING.

    gcc/testsuite/ChangeLog:

            * g++.dg/init/no-elide2.C: New test.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

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

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

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 11.2/12.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:019d6d4149ee97d55ce9efe4e5e470d38130cdeb

commit r12-8149-g019d6d4149ee97d55ce9efe4e5e470d38130cdeb
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Apr 13 12:44:54 2022 -0400

    c++: add test [PR105265]

    This was fixed by r12-1165, but good to have a test that doesn't need
    -fno-elide-constructors.

            PR c++/105265
            PR c++/100838

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/initlist-new6.C: New test.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:728f97cf0431ff342beceea4f91afa1707133248

commit r11-9985-g728f97cf0431ff342beceea4f91afa1707133248
Author: Jason Merrill <jason@redhat.com>
Date:   Wed Apr 13 20:18:33 2022 -0400

    c++: temp cleanup in new [PR105265]

    The patch for PR100838 in GCC 11 was limited to -fno-elide-constructors for
    safety, but this testcase demonstrates that it's also needed without that
    flag.  So let's switch to the GCC 12 patch for PR100838.

            PR c++/105265
            PR c++/100838

    gcc/cp/ChangeLog:

            * call.c (build_user_type_conversion_1): Drop
            flag_elide_constructors check.
            (convert_like_internal): Likewise.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/initlist-new6.C: New test.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:67f742536cbb60d5f8b7bba2cac0a141191e29af

commit r10-10727-g67f742536cbb60d5f8b7bba2cac0a141191e29af
Author: Jason Merrill <jason@redhat.com>
Date:   Mon May 31 12:36:25 2021 -0400

    c++: missing dtor with -fno-elide-constructors [PR100838]

    tf_no_cleanup only applies to the outermost TARGET_EXPR, and we already
    clear it for nested calls in build_over_call, but in this case both
    constructor calls came from convert_like, so we need to clear it in the
    recursive call as well.  This revealed that we were adding an extra
    ck_rvalue in direct-initialization cases where it was wrong.

            PR c++/100838
            PR c++/105265

    gcc/cp/ChangeLog:

            * call.c (convert_like_internal): Clear tf_no_cleanup when
            recursing.
            (build_user_type_conversion_1): Only add ck_rvalue if
            LOOKUP_ONLYCONVERTING.

    gcc/testsuite/ChangeLog:

            * g++.dg/init/no-elide2.C: New test.
            * g++.dg/cpp0x/initlist-new6.C: New test.

[Bug c++/100838] [11 Regression] -fno-elide-constructors for C++14 missing required destructor call since r11-5872-g4eb28483004f8291

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100838

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:200d477d3cb1593dbaa7739c6270e0a7f6c564cf

commit r9-10178-g200d477d3cb1593dbaa7739c6270e0a7f6c564cf
Author: Jason Merrill <jason@redhat.com>
Date:   Mon May 31 12:36:25 2021 -0400

    c++: missing dtor with -fno-elide-constructors [PR100838]

    tf_no_cleanup only applies to the outermost TARGET_EXPR, and we already
    clear it for nested calls in build_over_call, but in this case both
    constructor calls came from convert_like, so we need to clear it in the
    recursive call as well.  This revealed that we were adding an extra
    ck_rvalue in direct-initialization cases where it was wrong.

            PR c++/100838
            PR c++/105265

    gcc/cp/ChangeLog:

            * call.c (convert_like_internal): Clear tf_no_cleanup when
            recursing.
            (build_user_type_conversion_1): Only add ck_rvalue if
            LOOKUP_ONLYCONVERTING.

    gcc/testsuite/ChangeLog:

            * g++.dg/init/no-elide2.C: New test.
            * g++.dg/cpp0x/initlist-new6.C: New test.