[Bug c++/101140] New: [modules] no matching function for call to ‘operator new(sizetype, void*)’

["ensadc at mailnesia dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101140

            Bug ID: 101140
           Summary: [modules] no matching function for call to ‘operator
                    new(sizetype, void*)’
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ensadc at mailnesia dot com
  Target Milestone: ---

$ cat new.hpp
extern "C++" {
void* operator new(__SIZE_TYPE__, void* p);
}

$ cat foo.cpp
module;
#include "new.hpp"
export module foo;

export template<class T>
T* construct_at(T* p) {
    return ::new((void*)p) T();
}

$ cat bar.cpp
export module bar;

import foo;

void f(int* p) {
    construct_at(p);
}

$ g++ -std=c++20 -fmodules-ts -c foo.cpp
$ g++ -std=c++20 -fmodules-ts -c bar.cpp
In module foo, imported at bar.cpp:3:
foo.cpp: In instantiation of ‘T* construct_at@foo(T*) [with T = int]’:
bar.cpp:6:17:   required from here
foo.cpp:7:12: error: no matching function for call to ‘operator new(sizetype,
void*)’
    7 |     return ::new((void*)p) T();
      |            ^~~~~~~~~~~~~~~~~~~
<built-in>: note: candidate: ‘void* operator new(long unsigned int)’
<built-in>: note:   candidate expects 1 argument, 2 provided
<built-in>: note: candidate: ‘void* operator new(long unsigned int,
std::align_val_t)’
<built-in>: note:   no known conversion for argument 2 from ‘void*’ to
‘std::align_val_t’
bar.cpp:1:8: warning: not writing module ‘bar’ due to errors
    1 | export module bar;
      |        ^~~~~~

====

The error disappears if "new.hpp" is included or imported in `bar.cpp`.

I originally encountered this problem when using `std::construct_at` (defined
in`<memory>`) in a module.