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.
> 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
