| Message ID | 20240613143140.660743-1-kmatsui@gcc.gnu.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] gcc, libcpp: Add warning switch for "#pragma once in main file" [PR89808] | expand |
On Thu, 2024-06-13 at 07:31 -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. > > PR preprocessor/89808 > > gcc/c-family/ChangeLog: > > * c.opt (Wpragma_once_outside_header): Define new option. > > gcc/ChangeLog: > > * doc/invoke.texi (Warning Options): Document > -Wno-pragma-once-outside-header. > > libcpp/ChangeLog: > > * include/cpplib.h (struct cpp_options): Define > cpp_warn_pragma_once_outside_header. > (cpp_warning_reason): Define > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > * directives.cc (do_pragma_once): Use > cpp_warn_pragma_once_outside_header and > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > * init.cc (cpp_create_reader): Handle > cpp_warn_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 <kmatsui@gcc.gnu.org> [...snip...] Thanks for the updated patch. > @@ -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 Please run "make html && make regenerate-opt-urls" so that the diagnostic gets a documentation URL. Sorry that you have to do this manually (it's to avoid complicating the build dependencies for someone just building gcc). [...snip...] > diff --git a/libcpp/directives.cc b/libcpp/directives.cc > index 479f8c716e8..68f47104dea 100644 > --- a/libcpp/directives.cc > +++ b/libcpp/directives.cc > @@ -1588,8 +1588,12 @@ do_pragma (cpp_reader *pfile) > 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"); > + const unsigned char warn_level = > + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header); > + > + if (warn_level && _cpp_in_main_source_file (pfile)) > + cpp_warning (pfile, CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER, > + "#pragma once in main file"); Please put the "#pragma once" in the message in quotes, such as via: cpp_warning (pfile, CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER, "%<pragma once%> in main file"); or via: cpp_warning (pfile, CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER, "%qs in main file", "pragma once"); Although it's a minor style nit, I'm working on patches to automatically add URLs to GCC's documentation for certain quoted strings on sufficiently capable terminals (I've done command-line options, I'm working on attributes, and I hope to eventually do pragmas). Dave
On 6/13/24 10:31, 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. > > PR preprocessor/89808 > > gcc/c-family/ChangeLog: > > * c.opt (Wpragma_once_outside_header): Define new option. > > gcc/ChangeLog: > > * doc/invoke.texi (Warning Options): Document > -Wno-pragma-once-outside-header. > > libcpp/ChangeLog: > > * include/cpplib.h (struct cpp_options): Define > cpp_warn_pragma_once_outside_header. This bit-field should be unneeded now, along with the uses of it. > (cpp_warning_reason): Define CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > * directives.cc (do_pragma_once): Use > cpp_warn_pragma_once_outside_header and > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > * init.cc (cpp_create_reader): Handle > cpp_warn_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 <kmatsui@gcc.gnu.org> > --- > gcc/c-family/c.opt | 4 ++++ > 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 | 9 ++++++--- > libcpp/include/cpplib.h | 7 ++++++- > libcpp/init.cc | 1 + > 7 files changed, 36 insertions(+), 6 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/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..324b0638c3f > --- /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..68f47104dea 100644 > --- a/libcpp/directives.cc > +++ b/libcpp/directives.cc > @@ -1588,8 +1588,12 @@ do_pragma (cpp_reader *pfile) > 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"); > + const unsigned char warn_level = > + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header); > + > + if (warn_level && _cpp_in_main_source_file (pfile)) > + 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); > @@ -2822,4 +2826,3 @@ _cpp_bracket_include(cpp_reader *pfile) > { > return glue_header_name (pfile); > } > - > diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h > index c62374d3192..21deaf72ec5 100644 > --- a/libcpp/include/cpplib.h > +++ b/libcpp/include/cpplib.h > @@ -583,6 +583,10 @@ struct cpp_options > 2 if it should be a pedwarn. */ > unsigned char cpp_warn_invalid_utf8; > > + /* True if libcpp should warn about #pragma once outside of a header. > + 2 if it should be an error, i.e., -Werror. */ > + unsigned char cpp_warn_pragma_once_outside_header; > + > /* True if libcpp should warn about invalid forms of delimited or named > escape sequences. */ > bool cpp_warn_unicode; > @@ -701,7 +705,8 @@ 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 > diff --git a/libcpp/init.cc b/libcpp/init.cc > index c457fa659e7..ba6e5f08446 100644 > --- a/libcpp/init.cc > +++ b/libcpp/init.cc > @@ -235,6 +235,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table, > CPP_OPTION (pfile, cpp_warn_bidirectional) = bidirectional_unpaired; > CPP_OPTION (pfile, cpp_warn_invalid_utf8) = 0; > CPP_OPTION (pfile, cpp_warn_unicode) = 1; > + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header) = 1; > CPP_OPTION (pfile, cpp_input_charset_explicit) = 0; > > /* Default CPP arithmetic to something sensible for the host for the
On Thu, Jun 13, 2024 at 7:44 AM Jason Merrill <jason@redhat.com> wrote: > > On 6/13/24 10:31, 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. > > > > PR preprocessor/89808 > > > > gcc/c-family/ChangeLog: > > > > * c.opt (Wpragma_once_outside_header): Define new option. > > > > gcc/ChangeLog: > > > > * doc/invoke.texi (Warning Options): Document > > -Wno-pragma-once-outside-header. > > > > libcpp/ChangeLog: > > > > * include/cpplib.h (struct cpp_options): Define > > cpp_warn_pragma_once_outside_header. > > This bit-field should be unneeded now, along with the uses of it. Thank you! I'll update the patch shortly. > > > (cpp_warning_reason): Define CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > > * directives.cc (do_pragma_once): Use > > cpp_warn_pragma_once_outside_header and > > CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. > > * init.cc (cpp_create_reader): Handle > > cpp_warn_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 <kmatsui@gcc.gnu.org> > > --- > > gcc/c-family/c.opt | 4 ++++ > > 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 | 9 ++++++--- > > libcpp/include/cpplib.h | 7 ++++++- > > libcpp/init.cc | 1 + > > 7 files changed, 36 insertions(+), 6 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/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..324b0638c3f > > --- /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..68f47104dea 100644 > > --- a/libcpp/directives.cc > > +++ b/libcpp/directives.cc > > @@ -1588,8 +1588,12 @@ do_pragma (cpp_reader *pfile) > > 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"); > > + const unsigned char warn_level = > > + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header); > > + > > + if (warn_level && _cpp_in_main_source_file (pfile)) > > + 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); > > @@ -2822,4 +2826,3 @@ _cpp_bracket_include(cpp_reader *pfile) > > { > > return glue_header_name (pfile); > > } > > - > > diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h > > index c62374d3192..21deaf72ec5 100644 > > --- a/libcpp/include/cpplib.h > > +++ b/libcpp/include/cpplib.h > > @@ -583,6 +583,10 @@ struct cpp_options > > 2 if it should be a pedwarn. */ > > unsigned char cpp_warn_invalid_utf8; > > > > + /* True if libcpp should warn about #pragma once outside of a header. > > + 2 if it should be an error, i.e., -Werror. */ > > + unsigned char cpp_warn_pragma_once_outside_header; > > + > > /* True if libcpp should warn about invalid forms of delimited or named > > escape sequences. */ > > bool cpp_warn_unicode; > > @@ -701,7 +705,8 @@ 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 > > diff --git a/libcpp/init.cc b/libcpp/init.cc > > index c457fa659e7..ba6e5f08446 100644 > > --- a/libcpp/init.cc > > +++ b/libcpp/init.cc > > @@ -235,6 +235,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table, > > CPP_OPTION (pfile, cpp_warn_bidirectional) = bidirectional_unpaired; > > CPP_OPTION (pfile, cpp_warn_invalid_utf8) = 0; > > CPP_OPTION (pfile, cpp_warn_unicode) = 1; > > + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header) = 1; > > CPP_OPTION (pfile, cpp_input_charset_explicit) = 0; > > > > /* Default CPP arithmetic to something sensible for the host for the >
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/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..324b0638c3f --- /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..68f47104dea 100644 --- a/libcpp/directives.cc +++ b/libcpp/directives.cc @@ -1588,8 +1588,12 @@ do_pragma (cpp_reader *pfile) 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"); + const unsigned char warn_level = + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header); + + if (warn_level && _cpp_in_main_source_file (pfile)) + 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); @@ -2822,4 +2826,3 @@ _cpp_bracket_include(cpp_reader *pfile) { return glue_header_name (pfile); } - diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h index c62374d3192..21deaf72ec5 100644 --- a/libcpp/include/cpplib.h +++ b/libcpp/include/cpplib.h @@ -583,6 +583,10 @@ struct cpp_options 2 if it should be a pedwarn. */ unsigned char cpp_warn_invalid_utf8; + /* True if libcpp should warn about #pragma once outside of a header. + 2 if it should be an error, i.e., -Werror. */ + unsigned char cpp_warn_pragma_once_outside_header; + /* True if libcpp should warn about invalid forms of delimited or named escape sequences. */ bool cpp_warn_unicode; @@ -701,7 +705,8 @@ 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 diff --git a/libcpp/init.cc b/libcpp/init.cc index c457fa659e7..ba6e5f08446 100644 --- a/libcpp/init.cc +++ b/libcpp/init.cc @@ -235,6 +235,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table, CPP_OPTION (pfile, cpp_warn_bidirectional) = bidirectional_unpaired; CPP_OPTION (pfile, cpp_warn_invalid_utf8) = 0; CPP_OPTION (pfile, cpp_warn_unicode) = 1; + CPP_OPTION (pfile, cpp_warn_pragma_once_outside_header) = 1; CPP_OPTION (pfile, cpp_input_charset_explicit) = 0; /* Default CPP arithmetic to something sensible for the host for the
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. PR preprocessor/89808 gcc/c-family/ChangeLog: * c.opt (Wpragma_once_outside_header): Define new option. gcc/ChangeLog: * doc/invoke.texi (Warning Options): Document -Wno-pragma-once-outside-header. libcpp/ChangeLog: * include/cpplib.h (struct cpp_options): Define cpp_warn_pragma_once_outside_header. (cpp_warning_reason): Define CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. * directives.cc (do_pragma_once): Use cpp_warn_pragma_once_outside_header and CPP_W_PRAGMA_ONCE_OUTSIDE_HEADER. * init.cc (cpp_create_reader): Handle cpp_warn_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 <kmatsui@gcc.gnu.org> --- gcc/c-family/c.opt | 4 ++++ 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 | 9 ++++++--- libcpp/include/cpplib.h | 7 ++++++- libcpp/init.cc | 1 + 7 files changed, 36 insertions(+), 6 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