[Bug c++/98895] New: C++ module generates too many dead code

[Bug c++/98895] New: C++ module generates too many dead code

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98895

            Bug ID: 98895
           Summary: C++ module generates too many dead code
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: unlvsur at live dot com
  Target Milestone: ---

It is a general issue. Any module unit will generate a dead entry that is
completely unused.

If those issues cannot be solved, I am sorry, I would only say C++20 modules
failed completely.

I do not think it has anything to do with tree-optimizations. The compiler just
should NOT emit any code to the middle-end because of the module tbh. The
module should not affect how the assembly is generated.

[Bug c++/98895] C++ module generates too many dead code

[unlvsur at live dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98895

cqwrteur <unlvsur at live dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |All
               Host|                            |All

--- Comment #1 from cqwrteur <unlvsur at live dot com> ---
#include<stdio.h>
inline void test(char const* str) noexcept
{
    puts(str);
}

int main()
{
    test("Hello\n");
}

hello.cc
module;
#include<stdio.h>
export module hello;

export inline void test(char const* str) noexcept
{
    puts(str);
}


main.cc
import hello;

int main()
{
    test("Hello\n");
}


The 2nd generates a larger binary because it emits dead module entry.

Please remove all dead code thank you.

[Bug c++/98895] C++ module generates too many dead code

[pilarlatiesa at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98895

--- Comment #2 from Pilar Latiesa <pilarlatiesa at gmail dot com> ---
(In reply to cqwrteur from comment #0)

> If those issues cannot be solved, I am sorry, I would only say C++20 modules
> failed completely.

What do you expect from being so offensive? Is this comment necessary at all?
Do you realize that some people have devoted several years of work to have the
feature ready for us to use it for free?

[Bug c++/98895] C++ module generates too many dead code

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98895

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppalka at gcc dot gnu.org
         Resolution|---                         |FIXED
   Target Milestone|---                         |13.0
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
I suspect this is fixed on trunk by r13-1090-ge8609768fbbc1e