[Bug c++/108096] New: [13 regression] libreoffice build failure #2

[Bug c++/108096] New: [13 regression] libreoffice build failure #2

[manuel.lauss at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

            Bug ID: 108096
           Summary: [13 regression] libreoffice build failure #2
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: manuel.lauss at googlemail dot com
  Target Milestone: ---

Created attachment 54088
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54088&action=edit
comrpessed preprocessed source

This is a followup to PR108071.

With todays gcc-trunk (g:693638252aae9b36b5b928d7195df6d28bf409d7), libreoffice
build fails with another new error:

# g++ -c backupfilehelper.i
backupfilehelper.i: In instantiation of 'constexpr bool
std::__check_constructible() [with _ValueType = rtl::OUString; _Tp = const
char* const&]':
backupfilehelper.i:25254:119:   required from '_ForwardIterator
std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with
_InputIterator = const char* const*; _ForwardIterator = rtl::OUString*]'
backupfilehelper.i:25380:37:   required from '_ForwardIterator
std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator,
allocator<_Tp>&) [with _InputIterator = const char* const*; _ForwardIterator =
rtl::OUString*; _Tp = rtl::OUString]'
backupfilehelper.i:40712:33:   required from 'void std::vector<_Tp,
_Alloc>::_M_range_initialize(_ForwardIterator, _ForwardIterator,
std::forward_iterator_tag) [with _ForwardIterator = const char* const*; _Tp =
rtl::OUString; _Alloc = std::allocator<rtl::OUString>]'
backupfilehelper.i:40361:23:   required from 'std::vector<_Tp,
_Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&) [with
_InputIterator = const char* const*; <template-parameter-2-2> = void; _Tp =
rtl::OUString; _Alloc = std::allocator<rtl::OUString>; allocator_type =
std::allocator<rtl::OUString>]'
backupfilehelper.i:62388:9:   required from here
backupfilehelper.i:25201:56: error: static assertion failed: result type must
be constructible from input type
25201 |       static_assert(is_constructible<_ValueType, _Tp>::value,
      |                                                        ^~~~~
backupfilehelper.i:25201:56: note: 'std::integral_constant<bool, false>::value'
evaluates to false


The offending code is:

const std::vector< OUString >& f()
{
    static std::vector< OUString > aDirNames =
    {
            "config",
            "registry",
            "psprint",
            "store",
            "temp",
            "pack"
    };
    return aDirNames;
}


Find attached the compressed preprocessed source.

Thank you!
     Manuel

[Bug c++/108096] [13 regression] libreoffice build failure #2 since r13-4564

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2022-12-14
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |jason at gcc dot gnu.org,
                   |                            |redi at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
            Summary|[13 regression] libreoffice |[13 regression] libreoffice
                   |build failure #2            |build failure #2 since
                   |                            |r13-4564
           Priority|P3                          |P1
   Target Milestone|---                         |13.0

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This one started with r13-4564-gd081807d8d70e3e87eae41e1560e54d503f4d465

[Bug c++/108096] [13 regression] libreoffice build failure #2 since r13-4564

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Similar problem to PR 108071. The OUString type can only be constructed from
char(&)[N] and const char(&)[N], not from const char*. The original code
constructs initializer_list<OUString> and so each element is initialized
directly from an array. The new code decays the arrays to
initializer_list<const char*> and then fails to construct OUString objects from
const char* const values.

[Bug c++/108096] [13 regression] libreoffice build failure #2 since r13-4564

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced:

#include <initializer_list>

template<bool> struct enable_if { };
template<> struct enable_if<true> { using type = void; };

template<typename T> constexpr bool is_array_v = false;
template<typename T, std::size_t N> constexpr bool is_array_v<T[N]> = true;

struct OUString
{
  template<typename T, typename = typename enable_if<is_array_v<T>>::type>
  OUString(T&) { }
};

struct vector
{
  vector(std::initializer_list<OUString>) { }
  template<typename Iter>
  vector(Iter i, Iter j) { if (i != j) OUString(*i); }
};

vector v = { "" };

[Bug c++/108096] [13 regression] libreoffice build failure #2 since r13-4564

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

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

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

[Bug c++/108096] [13 regression] libreoffice build failure #2 since r13-4564

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108096

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

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

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed by r13-4712.