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 <kmat...@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 adiff --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
