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From: "svnpenn at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/97574] New: Allow for nul output with Windows
Date: Sun, 25 Oct 2020 22:56:32 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97574

            Bug ID: 97574
           Summary: Allow for nul output with Windows
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: svnpenn at gmail dot com
  Target Milestone: ---

Allow for nul output with Windows

A project I am trying to compile has this command:

    cc -xc++ -o/dev/null -lc++ -shared

However I am using PowerShell, which has no notion of `/dev/null`:

    PS C:\> cc -xc++ -o/dev/null -lc++ -shared
    C:/msys2/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../
    x86_64-w64-mingw32/bin/ld.exe: cannot open output file /dev/null.exe: No
    such file or directory

I tried using `-o$null`, but it just creates a file `$null.exe`. I also tri=
ed
this:

    PS C:\> cc -xc++ -o $null -lc++ -shared
    cc.exe: fatal error: no input files

It appears the issue is specific to GCC. If I get Clang [1], the same comma=
nd
works with `nul` [2]:

    cc -xc++ -onul -lc++ -shared

but if I try the same thing with GCC, I get this:

    C:/msys2/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../
    x86_64-w64-mingw32/bin/ld.exe: nul.exe: final close failed: file trunca=
ted

Alternatively, if anyone knows a better way to check the availability of a
library, I would be interested in that.

[1] https://github.com/mstorsjo/llvm-mingw
[2] https://support.microsoft.com/help/110930=