On Monday, October 7th, 2024 at 4:41 PM, Marek Polacek <pola...@redhat.com>
wrote:
>
>
> On Sat, Jun 15, 2024 at 10:30:35PM -0700, Ken Matsui wrote:
>
> > This patch adds a warning switch for "#pragma once in main file". The
> > warning option name is Wpragma-once-outside-header, which is the same
> > as Clang provides.
>
>
> I think the patch is OK now, thanks. Other diagnostics inlude the '#'
> character but I know you just did what David suggested.
Thank you for your review! It might be better to keep consistency between
other compilers, but do we proceed with the current change?
Just to confirm, since you are a C front end reviewer, am I now ok to push this
patch?
>
> > PR preprocessor/89808
> >
> > gcc/c-family/ChangeLog:
> >
> > * c.opt (Wpragma_once_outside_header): Define new option.
> > * c.opt.urls: Regenerate.
> >
> > gcc/ChangeLog:
> >
> > * doc/invoke.texi (Warning Options): Document
> > -Wno-pragma-once-outside-header.
> >
> > libcpp/ChangeLog:
> >
> > * include/cpplib.h (cpp_warning_reason): Define
> > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER.
> > * directives.cc (do_pragma_once): Use
> > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/warn/Wno-pragma-once-outside-header.C: New test.
> > * g++.dg/warn/Wpragma-once-outside-header.C: New test.
> >
> > Signed-off-by: Ken Matsui kmat...@gcc.gnu.org
> > ---
> > gcc/c-family/c.opt | 4 ++++
> > gcc/c-family/c.opt.urls | 3 +++
> > gcc/doc/invoke.texi | 10 ++++++++--
> > .../g++.dg/warn/Wno-pragma-once-outside-header.C | 5 +++++
> > .../g++.dg/warn/Wpragma-once-outside-header.C | 6 ++++++
> > libcpp/directives.cc | 3 ++-
> > libcpp/include/cpplib.h | 3 ++-
> > 7 files changed, 30 insertions(+), 4 deletions(-)
> > create mode 100644
> > gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
> > create mode 100644 gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
> >
> > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> > index 403abc1f26e..3439f36fe45 100644
> > --- a/gcc/c-family/c.opt
> > +++ b/gcc/c-family/c.opt
> > @@ -1188,6 +1188,10 @@ Wpragmas
> > C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
> > Warn about misuses of pragmas.
> >
> > +Wpragma-once-outside-header
> > +C ObjC C++ ObjC++ Var(warn_pragma_once_outside_header)
> > CppReason(CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER) Init(1) Warning
> > +Warn about #pragma once outside of a header.
> > +
> > Wprio-ctor-dtor
> > C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
> > Warn if constructor or destructors with priorities from 0 to 100 are used.
> > diff --git a/gcc/c-family/c.opt.urls b/gcc/c-family/c.opt.urls
> > index dd455d7c0dc..778ca08be2e 100644
> > --- a/gcc/c-family/c.opt.urls
> > +++ b/gcc/c-family/c.opt.urls
> > @@ -672,6 +672,9 @@
> > UrlSuffix(gcc/Warning-Options.html#index-Wno-pointer-to-int-cast)
> > Wpragmas
> > UrlSuffix(gcc/Warning-Options.html#index-Wno-pragmas)
> >
> > +Wpragma-once-outside-header
> > +UrlSuffix(gcc/Warning-Options.html#index-Wno-pragma-once-outside-header)
> > +
> > Wprio-ctor-dtor
> > UrlSuffix(gcc/Warning-Options.html#index-Wno-prio-ctor-dtor)
> >
> > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> > index 9456ced468a..c7f17ca9eb7 100644
> > --- a/gcc/doc/invoke.texi
> > +++ b/gcc/doc/invoke.texi
> > @@ -391,8 +391,8 @@ Objective-C and Objective-C++ Dialects}.
> > -Wpacked -Wno-packed-bitfield-compat -Wpacked-not-aligned -Wpadded
> > -Wparentheses -Wno-pedantic-ms-format
> > -Wpointer-arith -Wno-pointer-compare -Wno-pointer-to-int-cast
> > --Wno-pragmas -Wno-prio-ctor-dtor -Wredundant-decls
> > --Wrestrict -Wno-return-local-addr -Wreturn-type
> > +-Wno-pragmas -Wno-pragma-once-outside-header -Wno-prio-ctor-dtor
> > +-Wredundant-decls -Wrestrict -Wno-return-local-addr -Wreturn-type
> > -Wno-scalar-storage-order -Wsequence-point
> > -Wshadow -Wshadow=global -Wshadow=local -Wshadow=compatible-local
> > -Wno-shadow-ivar
> > @@ -7983,6 +7983,12 @@ Do not warn about misuses of pragmas, such as
> > incorrect parameters,
> > invalid syntax, or conflicts between pragmas. See also
> > @option{-Wunknown-pragmas}.
> >
> > +@opindex Wno-pragma-once-outside-header
> > +@opindex Wpragma-once-outside-header
> > +@item -Wno-pragma-once-outside-header
> > +Do not warn when @code{#pragma once} is used in a file that is not a header
> > +file, such as a main file.
> > +
> > @opindex Wno-prio-ctor-dtor
> > @opindex Wprio-ctor-dtor
> > @item -Wno-prio-ctor-dtor
> > diff --git a/gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
> > b/gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
> > new file mode 100644
> > index 00000000000..b5be4d25a9d
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
> > @@ -0,0 +1,5 @@
> > +// { dg-do assemble }
> > +// { dg-options "-Wno-pragma-once-outside-header" }
> > +
> > +#pragma once
> > +int main() {}
> > diff --git a/gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
> > b/gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
> > new file mode 100644
> > index 00000000000..29f09b69f71
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
> > @@ -0,0 +1,6 @@
> > +// { dg-do assemble }
> > +// { dg-options "-Werror=pragma-once-outside-header" }
> > +// { dg-message "some warnings being treated as errors" "" {target "--*"}
> > 0 }
> > +
> > +#pragma once // { dg-error "'pragma once' in main file" }
> > +int main() {}
> > diff --git a/libcpp/directives.cc b/libcpp/directives.cc
> > index 479f8c716e8..467efdf637d 100644
> > --- a/libcpp/directives.cc
> > +++ b/libcpp/directives.cc
> > @@ -1589,7 +1589,8 @@ static void
> > do_pragma_once (cpp_reader *pfile)
> > {
> > if (_cpp_in_main_source_file (pfile))
> > - cpp_error (pfile, CPP_DL_WARNING, "#pragma once in main file");
> > + cpp_warning (pfile, CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER,
> > + "%<pragma once%> in main file");
> >
> > check_eol (pfile, false);
> > _cpp_mark_file_once_only (pfile, pfile->buffer->file);
> > diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
> > index c62374d3192..da915e2101e 100644
> > --- a/libcpp/include/cpplib.h
> > +++ b/libcpp/include/cpplib.h
> > @@ -701,7 +701,8 @@ enum cpp_warning_reason {
> > CPP_W_EXPANSION_TO_DEFINED,
> > CPP_W_BIDIRECTIONAL,
> > CPP_W_INVALID_UTF8,
> > - CPP_W_UNICODE
> > + CPP_W_UNICODE,
> > + CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER
> > };
> >
> > /* Callback for header lookup for HEADER, which is the name of a
> > --
> > 2.45.1
>
>
> Marek
