[Bug c++/61412] Warnings incorrectly suppressed when compiling previously preprocessed file

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61412

Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |manu at gcc dot gnu.org

--- Comment #7 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> ---
(In reply to Matt Godbolt from comment #5)
> 
> That 250K+ file also exhibits the problem: that is, the warning is
> suppressed even within the main body of the file. I then whittled down the
> preprocessed file to just those two lines. In the original file the "# ..."
> line came from the middle of a macro expansion defined by a header included
> via an -isystem path. The filename in the "# " line refers to the C++ file
> though in both cases.

Sorry, this is a bit confusing.

The line in question comes before preprocessing from which file? Is this file
marked as a system-header? If yes, then why do you expect to get a warning
without -Wsystem-headers? If not, did you edit the processed file? Could we get
the processed file without editing (or at least without removing any
line-markers)?