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-opts.cc (c_common_handle_option): Handle OPT_Wpragma_once_outside_header. * 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. * directives.cc (do_pragma_once): Use cpp_warn_pragma_once_outside_header. * init.cc (cpp_create_reader): Handle cpp_warn_pragma_once_outside_header. gcc/testsuite/ChangeLog: * g++.dg/Wpragma-once-outside-header.C: New test. * 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-opts.cc | 9 +++++++++ gcc/c-family/c.opt | 4 ++++ gcc/doc/invoke.texi | 10 ++++++++-- gcc/testsuite/g++.dg/Wpragma-once-outside-header.C | 5 +++++ .../g++.dg/warn/Wno-pragma-once-outside-header.C | 5 +++++ .../g++.dg/warn/Wpragma-once-outside-header.C | 5 +++++ libcpp/directives.cc | 8 ++++++-- libcpp/include/cpplib.h | 4 ++++ libcpp/init.cc | 1 + 9 files changed, 47 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C 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-opts.cc b/gcc/c-family/c-opts.cc index be3058dca63..4edd8c6c515 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -430,6 +430,15 @@ c_common_handle_option (size_t scode, const char *arg, HOST_WIDE_INT value, cpp_opts->warn_num_sign_change = value; break; + case OPT_Wpragma_once_outside_header: + if (value == 0) + cpp_opts->cpp_warn_pragma_once_outside_header = 0; + else if (kind == DK_ERROR) + cpp_opts->cpp_warn_pragma_once_outside_header = 2; + else + cpp_opts->cpp_warn_pragma_once_outside_header = 1; + break; + case OPT_Wunknown_pragmas: /* Set to greater than 1, so that even unknown pragmas in system headers will be warned about. */ diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index b7a4a1a68e3..6841a5a5e81 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -1180,6 +1180,10 @@ 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) 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 bdf05be387d..eeb8954bcdf 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 @@ -7955,6 +7955,12 @@ 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/Wpragma-once-outside-header.C b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C new file mode 100644 index 00000000000..678bd4e7626 --- /dev/null +++ b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C @@ -0,0 +1,5 @@ +/* { dg-do assemble } */ +/* { dg-options "-Werror=pragma-once-outside-header" } */ + +#pragma once // { dg-error "#pragma once in main file" } +int main() {} 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..ae958d3beb8 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C @@ -0,0 +1,5 @@ +// { dg-do assemble } +// { dg-options "-Werror=pragma-once-outside-header" } + +#pragma once // { dg-error "#pragma once in main file" } +int main() {} diff --git a/libcpp/directives.cc b/libcpp/directives.cc index 479f8c716e8..b6121a459f8 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_error (pfile, (warn_level == 1 ? CPP_DL_WARNING : CPP_DL_ERROR), + "#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..d25b9606153 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; diff --git a/libcpp/init.cc b/libcpp/init.cc index 54fc9236d38..4be1afdb2c2 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 -- 2.44.0