| Message ID | 20230512205332.1781029-1-jason@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] c-family: make -fno-permissive upgrade pedwarns | expand |
On Fri, May 12, 2023 at 10:54 PM Jason Merrill via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > In the context of the recent discussion, it occurred to me that this semantic > would be useful, but currently there is no easy way to access it. Bikeshedding > welcome; the use of this flag is a bit odd, but it has the advantage of being > accepted without error going back at least to 4.3. > > -- 8< -- > > Currently there is no flag to use to upgrade all currently-enabled pedwarns > from warning to error. -pedantic-errors also enables the -Wpedantic > pedwarns, while -Werror=pedantic uselessly makes only the -Wpedantic > pedwarns errors. > > I suggest that since -fpermissive lowers some diagnostics from error to > warning, -fno-permissive could do the reverse. Hmm, but that makes '-fno-permissive' different from '-fpermissive -fno-permissive'? What about '-fpermissive -fno-permissive -fno-permissive' then? So I think over-loading -fno-permissive with differen semantics from negating the option is bad. Richard. > > gcc/ChangeLog: > > * doc/invoke.texi: Document -fno-permissive. > > gcc/c-family/ChangeLog: > > * c.opt (fpermissive): Accept in C and ObjC as well. > * c-opts.cc (c_common_post_options): -fno-permissive sets > global_dc->pedantic_errors. > --- > gcc/doc/invoke.texi | 7 +++++++ > gcc/c-family/c.opt | 2 +- > gcc/c-family/c-opts.cc | 4 ++++ > 3 files changed, 12 insertions(+), 1 deletion(-) > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index b92b8576027..6198df14382 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -3438,11 +3438,18 @@ issue. Currently, the only such diagnostic issued by G++ is the one for > a name having multiple meanings within a class. > > @opindex fpermissive > +@opindex fno-permissive > @item -fpermissive > Downgrade some diagnostics about nonconformant code from errors to > warnings. Thus, using @option{-fpermissive} allows some > nonconforming code to compile. > > +Conversely, @option{-fno-permissive} can be used to upgrade some > +diagnostics about nonconformant code from warnings to errors. This > +differs from @option{-pedantic-errors} in that the latter also implies > +@option{-Wpedantic}; this option does not enable additional > +diagnostics, only upgrades the severity of those that are enabled. > + > @opindex fno-pretty-templates > @opindex fpretty-templates > @item -fno-pretty-templates > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > index 3333cddeece..07165d2bbe8 100644 > --- a/gcc/c-family/c.opt > +++ b/gcc/c-family/c.opt > @@ -2075,7 +2075,7 @@ C ObjC C++ ObjC++ > Look for and use PCH files even when preprocessing. > > fpermissive > -C++ ObjC++ Var(flag_permissive) > +C ObjC C++ ObjC++ Var(flag_permissive) > Downgrade conformance errors to warnings. > > fplan9-extensions > diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc > index c68a2a27469..1973c068d59 100644 > --- a/gcc/c-family/c-opts.cc > +++ b/gcc/c-family/c-opts.cc > @@ -1021,6 +1021,10 @@ c_common_post_options (const char **pfilename) > SET_OPTION_IF_UNSET (&global_options, &global_options_set, > flag_delete_dead_exceptions, true); > > + if (!global_options_set.x_flag_pedantic_errors > + && global_options_set.x_flag_permissive) > + global_dc->pedantic_errors = !flag_permissive; > + > if (cxx_dialect >= cxx11) > { > /* If we're allowing C++0x constructs, don't warn about C++98 > > base-commit: 62c4d34ec005e95f000ffabd34da440dc62ac346 > -- > 2.31.1 >
On 5/15/23 03:32, Richard Biener wrote: > On Fri, May 12, 2023 at 10:54 PM Jason Merrill via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: >> >> In the context of the recent discussion, it occurred to me that this semantic >> would be useful, but currently there is no easy way to access it. Bikeshedding >> welcome; the use of this flag is a bit odd, but it has the advantage of being >> accepted without error going back at least to 4.3. >> >> -- 8< -- >> >> Currently there is no flag to use to upgrade all currently-enabled pedwarns >> from warning to error. -pedantic-errors also enables the -Wpedantic >> pedwarns, while -Werror=pedantic uselessly makes only the -Wpedantic >> pedwarns errors. >> >> I suggest that since -fpermissive lowers some diagnostics from error to >> warning, -fno-permissive could do the reverse. > > Hmm, but that makes '-fno-permissive' different from '-fpermissive > -fno-permissive'? > What about '-fpermissive -fno-permissive -fno-permissive' then? > > So I think over-loading -fno-permissive with differen semantics from negating > the option is bad. Fair enough. Any other thoughts? It occurs to me now that it is already possible to specify this behavior with -pedantic-errors -Wno-pedantic, maybe that's sufficient if a bit cumbersome. >> gcc/ChangeLog: >> >> * doc/invoke.texi: Document -fno-permissive. >> >> gcc/c-family/ChangeLog: >> >> * c.opt (fpermissive): Accept in C and ObjC as well. >> * c-opts.cc (c_common_post_options): -fno-permissive sets >> global_dc->pedantic_errors. >> --- >> gcc/doc/invoke.texi | 7 +++++++ >> gcc/c-family/c.opt | 2 +- >> gcc/c-family/c-opts.cc | 4 ++++ >> 3 files changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi >> index b92b8576027..6198df14382 100644 >> --- a/gcc/doc/invoke.texi >> +++ b/gcc/doc/invoke.texi >> @@ -3438,11 +3438,18 @@ issue. Currently, the only such diagnostic issued by G++ is the one for >> a name having multiple meanings within a class. >> >> @opindex fpermissive >> +@opindex fno-permissive >> @item -fpermissive >> Downgrade some diagnostics about nonconformant code from errors to >> warnings. Thus, using @option{-fpermissive} allows some >> nonconforming code to compile. >> >> +Conversely, @option{-fno-permissive} can be used to upgrade some >> +diagnostics about nonconformant code from warnings to errors. This >> +differs from @option{-pedantic-errors} in that the latter also implies >> +@option{-Wpedantic}; this option does not enable additional >> +diagnostics, only upgrades the severity of those that are enabled. >> + >> @opindex fno-pretty-templates >> @opindex fpretty-templates >> @item -fno-pretty-templates >> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt >> index 3333cddeece..07165d2bbe8 100644 >> --- a/gcc/c-family/c.opt >> +++ b/gcc/c-family/c.opt >> @@ -2075,7 +2075,7 @@ C ObjC C++ ObjC++ >> Look for and use PCH files even when preprocessing. >> >> fpermissive >> -C++ ObjC++ Var(flag_permissive) >> +C ObjC C++ ObjC++ Var(flag_permissive) >> Downgrade conformance errors to warnings. >> >> fplan9-extensions >> diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc >> index c68a2a27469..1973c068d59 100644 >> --- a/gcc/c-family/c-opts.cc >> +++ b/gcc/c-family/c-opts.cc >> @@ -1021,6 +1021,10 @@ c_common_post_options (const char **pfilename) >> SET_OPTION_IF_UNSET (&global_options, &global_options_set, >> flag_delete_dead_exceptions, true); >> >> + if (!global_options_set.x_flag_pedantic_errors >> + && global_options_set.x_flag_permissive) >> + global_dc->pedantic_errors = !flag_permissive; >> + >> if (cxx_dialect >= cxx11) >> { >> /* If we're allowing C++0x constructs, don't warn about C++98 >> >> base-commit: 62c4d34ec005e95f000ffabd34da440dc62ac346 >> -- >> 2.31.1 >> >
On Mon, May 15, 2023 at 3:56 PM Jason Merrill <jason@redhat.com> wrote: > > On 5/15/23 03:32, Richard Biener wrote: > > On Fri, May 12, 2023 at 10:54 PM Jason Merrill via Gcc-patches > > <gcc-patches@gcc.gnu.org> wrote: > >> > >> In the context of the recent discussion, it occurred to me that this semantic > >> would be useful, but currently there is no easy way to access it. Bikeshedding > >> welcome; the use of this flag is a bit odd, but it has the advantage of being > >> accepted without error going back at least to 4.3. > >> > >> -- 8< -- > >> > >> Currently there is no flag to use to upgrade all currently-enabled pedwarns > >> from warning to error. -pedantic-errors also enables the -Wpedantic > >> pedwarns, while -Werror=pedantic uselessly makes only the -Wpedantic > >> pedwarns errors. > >> > >> I suggest that since -fpermissive lowers some diagnostics from error to > >> warning, -fno-permissive could do the reverse. > > > > Hmm, but that makes '-fno-permissive' different from '-fpermissive > > -fno-permissive'? > > What about '-fpermissive -fno-permissive -fno-permissive' then? > > > > So I think over-loading -fno-permissive with differen semantics from negating > > the option is bad. > > Fair enough. Any other thoughts? It occurs to me now that it is > already possible to specify this behavior with -pedantic-errors > -Wno-pedantic, maybe that's sufficient if a bit cumbersome. I guess so. Maybe the -fpermissive documentation could hint at that for this case? Richard. > >> gcc/ChangeLog: > >> > >> * doc/invoke.texi: Document -fno-permissive. > >> > >> gcc/c-family/ChangeLog: > >> > >> * c.opt (fpermissive): Accept in C and ObjC as well. > >> * c-opts.cc (c_common_post_options): -fno-permissive sets > >> global_dc->pedantic_errors. > >> --- > >> gcc/doc/invoke.texi | 7 +++++++ > >> gcc/c-family/c.opt | 2 +- > >> gcc/c-family/c-opts.cc | 4 ++++ > >> 3 files changed, 12 insertions(+), 1 deletion(-) > >> > >> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > >> index b92b8576027..6198df14382 100644 > >> --- a/gcc/doc/invoke.texi > >> +++ b/gcc/doc/invoke.texi > >> @@ -3438,11 +3438,18 @@ issue. Currently, the only such diagnostic issued by G++ is the one for > >> a name having multiple meanings within a class. > >> > >> @opindex fpermissive > >> +@opindex fno-permissive > >> @item -fpermissive > >> Downgrade some diagnostics about nonconformant code from errors to > >> warnings. Thus, using @option{-fpermissive} allows some > >> nonconforming code to compile. > >> > >> +Conversely, @option{-fno-permissive} can be used to upgrade some > >> +diagnostics about nonconformant code from warnings to errors. This > >> +differs from @option{-pedantic-errors} in that the latter also implies > >> +@option{-Wpedantic}; this option does not enable additional > >> +diagnostics, only upgrades the severity of those that are enabled. > >> + > >> @opindex fno-pretty-templates > >> @opindex fpretty-templates > >> @item -fno-pretty-templates > >> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > >> index 3333cddeece..07165d2bbe8 100644 > >> --- a/gcc/c-family/c.opt > >> +++ b/gcc/c-family/c.opt > >> @@ -2075,7 +2075,7 @@ C ObjC C++ ObjC++ > >> Look for and use PCH files even when preprocessing. > >> > >> fpermissive > >> -C++ ObjC++ Var(flag_permissive) > >> +C ObjC C++ ObjC++ Var(flag_permissive) > >> Downgrade conformance errors to warnings. > >> > >> fplan9-extensions > >> diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc > >> index c68a2a27469..1973c068d59 100644 > >> --- a/gcc/c-family/c-opts.cc > >> +++ b/gcc/c-family/c-opts.cc > >> @@ -1021,6 +1021,10 @@ c_common_post_options (const char **pfilename) > >> SET_OPTION_IF_UNSET (&global_options, &global_options_set, > >> flag_delete_dead_exceptions, true); > >> > >> + if (!global_options_set.x_flag_pedantic_errors > >> + && global_options_set.x_flag_permissive) > >> + global_dc->pedantic_errors = !flag_permissive; > >> + > >> if (cxx_dialect >= cxx11) > >> { > >> /* If we're allowing C++0x constructs, don't warn about C++98 > >> > >> base-commit: 62c4d34ec005e95f000ffabd34da440dc62ac346 > >> -- > >> 2.31.1 > >> > > >
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index b92b8576027..6198df14382 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -3438,11 +3438,18 @@ issue. Currently, the only such diagnostic issued by G++ is the one for a name having multiple meanings within a class. @opindex fpermissive +@opindex fno-permissive @item -fpermissive Downgrade some diagnostics about nonconformant code from errors to warnings. Thus, using @option{-fpermissive} allows some nonconforming code to compile. +Conversely, @option{-fno-permissive} can be used to upgrade some +diagnostics about nonconformant code from warnings to errors. This +differs from @option{-pedantic-errors} in that the latter also implies +@option{-Wpedantic}; this option does not enable additional +diagnostics, only upgrades the severity of those that are enabled. + @opindex fno-pretty-templates @opindex fpretty-templates @item -fno-pretty-templates diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 3333cddeece..07165d2bbe8 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -2075,7 +2075,7 @@ C ObjC C++ ObjC++ Look for and use PCH files even when preprocessing. fpermissive -C++ ObjC++ Var(flag_permissive) +C ObjC C++ ObjC++ Var(flag_permissive) Downgrade conformance errors to warnings. fplan9-extensions diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc index c68a2a27469..1973c068d59 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -1021,6 +1021,10 @@ c_common_post_options (const char **pfilename) SET_OPTION_IF_UNSET (&global_options, &global_options_set, flag_delete_dead_exceptions, true); + if (!global_options_set.x_flag_pedantic_errors + && global_options_set.x_flag_permissive) + global_dc->pedantic_errors = !flag_permissive; + if (cxx_dialect >= cxx11) { /* If we're allowing C++0x constructs, don't warn about C++98