Darn, not even sending it from my friend's mail account worked to combat
the patch formatting issues. Not only is the patch a complete wreck on the
mailing list archive, but my friend's mail account has now somehow merged
into mine on the list, resulting in a truly confusing author display name.
I really hope you've somehow gotten the patch intact on your end...
best regards,
Julian
On Fri, Jul 19, 2024 at 11:47 AM Tay Joseph <tanksherma...@gmail.com> wrote:
> Hi Jason,
>
>
>
> I’ve managed to address your review comments, and rewrite the patch to
> include both -Winvalid-noreturn and -Winvalid-noreturn= but have trouble
> figuring out how to format invoke.texi and where to add the documentation
> for the new warning options. I’ve also made this a Common option, since
> it’s come to my attention that the warning is not specific to c-family, but
> is also used by other languages too (See tree-cfg.cc). Here’s the current
> version of the patch, hope it’s good to go this time
>
>
>
> best regards,
>
> Julian
>
>
>
> From fe1b4d5747e05101410b6bb6db9430362e3977d9 Mon Sep 17 00:00:00 2001
>
> From: Julian Waters <tanksherma...@gmail.com>
>
> Date: Fri, 19 Jul 2024 11:22:38 +0800
>
> Subject: [PATCH] Introduce the -Winvalid-noreturn flag from clang with
> extra
>
> tuneability
>
>
>
> Currently, gcc warns about noreturn marked functions that return both
> explicitly and implicitly, with no way to turn this warning off. clang does
> have an option for these classes of warnings, -Winvalid-noreturn. However,
> we can do better. Instead of just having 1 option that switches the
> warnings for both on and off, we can define an extra layer of granularity,
> and have a separate options for implicit returns and explicit returns, as
> in -Winvalid-return=explicit and -Winvalid-noreturn=implicit, on top of the
> regular -Winvalid-noreturn. This patch adds both to gcc, for compatibility
> with clang.
>
>
>
> gcc/ChangeLog:
>
>
>
> * common.opt: Introduce -Winvalid-noreturn and -Winvalid-noreturn=
>
> * opts.cc (common_handle_option): Handle new option
>
> * flag-types.h: New flags for -Winvalid-noreturn=
>
> * tree-cfg.cc (pass_warn_function_return::execute): Use it
>
>
>
> gcc/c/ChangeLog:
>
>
>
> * c-typeck.cc (c_finish_return): Use it
>
> * gimple-parser.cc (c_finish_gimple_return): Use it
>
>
>
> gcc/config/mingw/ChangeLog:
>
>
>
> * mingw32.h (EXTRA_OS_CPP_BUILTINS): Fix semicolons
>
>
>
> gcc/cp/ChangeLog:
>
>
>
> * coroutines.cc (finish_co_return_stmt): Use it
>
> * typeck.cc (check_return_expr): Use it
>
>
>
> Signed-off-by: Julian Waters <tanksherma...@gmail.com>
>
> ---
>
> gcc/c/c-typeck.cc | 4 ++--
>
> gcc/c/gimple-parser.cc | 4 ++--
>
> gcc/common.opt | 13 +++++++++++++
>
> gcc/config/mingw/mingw32.h | 6 +++---
>
> gcc/cp/coroutines.cc | 4 ++--
>
> gcc/cp/typeck.cc | 4 ++--
>
> gcc/flag-types.h | 7 +++++++
>
> gcc/opts.cc | 19 +++++++++++++++++++
>
> gcc/tree-cfg.cc | 3 ++-
>
> 9 files changed, 52 insertions(+), 12 deletions(-)
>
>
>
> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
>
> index 7e0f01ed22b..0f8c8cfff2e 100644
>
> --- a/gcc/c/c-typeck.cc
>
> +++ b/gcc/c/c-typeck.cc
>
> @@ -11738,8 +11738,8 @@ c_finish_return (location_t loc, tree retval, tree
> origtype)
>
> in a function returning void. */
>
> location_t xloc = expansion_point_location_if_in_system_header (loc);
>
> - if (TREE_THIS_VOLATILE (current_function_decl))
>
> - warning_at (xloc, 0,
>
> + if (TREE_THIS_VOLATILE (current_function_decl) && flag_invalid_noreturn
> != invalid_noreturn_kind::EXPLICIT)
>
> + warning_at (xloc, OPT_Winvalid_noreturn,
>
> "function declared %<noreturn%> has a %<return%>
> statement");
>
> if (retval)
>
> diff --git a/gcc/c/gimple-parser.cc b/gcc/c/gimple-parser.cc
>
> index d156d83cd37..8a684fe334a 100644
>
> --- a/gcc/c/gimple-parser.cc
>
> +++ b/gcc/c/gimple-parser.cc
>
> @@ -2592,8 +2592,8 @@ c_finish_gimple_return (location_t loc, tree retval)
>
> in a function returning void. */
>
> location_t xloc = expansion_point_location_if_in_system_header (loc);
>
> - if (TREE_THIS_VOLATILE (current_function_decl))
>
> - warning_at (xloc, 0,
>
> + if (TREE_THIS_VOLATILE (current_function_decl) && flag_invalid_noreturn
> != invalid_noreturn_kind::EXPLICIT)
>
> + warning_at (xloc, OPT_Winvalid_noreturn,
>
> "function declared %<noreturn%> has a %<return%>
> statement");
>
> if (! retval)
>
> diff --git a/gcc/common.opt b/gcc/common.opt
>
> index ea39f87ae71..d44ff0231c3 100644
>
> --- a/gcc/common.opt
>
> +++ b/gcc/common.opt
>
> @@ -94,6 +94,11 @@ void *flag_instrument_functions_exclude_files
>
> Variable
>
> void *flag_ignored_attributes
>
> +; The noreturn kind to ignore when warning for noreturn code that
>
> +; does return.
>
> +Variable
>
> +invalid_noreturn_kind flag_invalid_noreturn = invalid_noreturn_kind::NONE
>
> +
>
> ; Generic structs (e.g. templates not explicitly specialized)
>
> ; may not have a compilation unit associated with them, and so
>
> ; may need to be treated differently from ordinary structs.
>
> @@ -667,6 +672,14 @@ Winvalid-memory-model
>
> Common Var(warn_invalid_memory_model) Init(1) Warning
>
> Warn when an atomic memory model parameter is known to be outside the
> valid range.
>
> +Winvalid-noreturn
>
> +Common Warning
>
> +Warn when code marked noreturn returns implicitly and/or explicitly.
>
> +
>
> +Winvalid-noreturn=
>
> +Common Joined Warning
>
> +Warn when code marked noreturn returns in the manner specified.
>
> +
>
> Wlarger-than-
>
> Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
>
> diff --git a/gcc/config/mingw/mingw32.h b/gcc/config/mingw/mingw32.h
>
> index 0dfe8e995b6..48eadfa2c2c 100644
>
> --- a/gcc/config/mingw/mingw32.h
>
> +++ b/gcc/config/mingw/mingw32.h
>
> @@ -35,9 +35,9 @@ along with GCC; see the file COPYING3. If not see
>
> | MASK_MS_BITFIELD_LAYOUT)
>
> #ifdef TARGET_USING_MCFGTHREAD
>
> -#define DEFINE_THREAD_MODEL builtin_define ("__USING_MCFGTHREAD__");
>
> +#define DEFINE_THREAD_MODEL builtin_define ("__USING_MCFGTHREAD__")
>
> #elif defined(TARGET_USE_PTHREAD_BY_DEFAULT)
>
> -#define DEFINE_THREAD_MODEL builtin_define ("__USING_POSIXTHREAD__");
>
> +#define DEFINE_THREAD_MODEL builtin_define ("__USING_POSIXTHREAD__")
>
> #else
>
> #define DEFINE_THREAD_MODEL
>
> #endif
>
> @@ -60,7 +60,7 @@ along with GCC; see the file COPYING3. If not see
>
> builtin_define_std
> ("WIN64"); \
>
> builtin_define ("_WIN64");
> \
>
>
> }
> \
>
> - DEFINE_THREAD_MODEL \
>
> +
> DEFINE_THREAD_MODEL; \
>
>
> }
> \
>
> while (0)
>
> diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
>
> index f350fc33e9b..f49ff82b1ee 100644
>
> --- a/gcc/cp/coroutines.cc
>
> +++ b/gcc/cp/coroutines.cc
>
> @@ -1374,8 +1374,8 @@ finish_co_return_stmt (location_t kw, tree expr)
>
> }
>
> /* Makes no sense for a co-routine really. */
>
> - if (TREE_THIS_VOLATILE (current_function_decl))
>
> - warning_at (kw, 0,
>
> + if (TREE_THIS_VOLATILE (current_function_decl) && flag_invalid_noreturn
> != invalid_noreturn_kind::EXPLICIT)
>
> + warning_at (kw, OPT_Winvalid_noreturn,
>
> "function declared %<noreturn%> has a"
>
> " %<co_return%> statement");
>
> diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
>
> index 8df8b871676..260a9f99b08 100644
>
> --- a/gcc/cp/typeck.cc
>
> +++ b/gcc/cp/typeck.cc
>
> @@ -11080,8 +11080,8 @@ check_return_expr (tree retval, bool *no_warning,
> bool *dangling)
>
> /* A `volatile' function is one that isn't supposed to return, ever.
>
> (This is a G++ extension, used to get better code for functions
>
> that call the `volatile' function.) */
>
> - if (TREE_THIS_VOLATILE (current_function_decl))
>
> - warning (0, "function declared %<noreturn%> has a %<return%>
> statement");
>
> + if (TREE_THIS_VOLATILE (current_function_decl) && flag_invalid_noreturn
> != invalid_noreturn_kind::EXPLICIT)
>
> + warning (OPT_Winvalid_noreturn, "function declared %<noreturn%> has a
> %<return%> statement");
>
> /* Check for various simple errors. */
>
> if (DECL_DESTRUCTOR_P (current_function_decl))
>
> diff --git a/gcc/flag-types.h b/gcc/flag-types.h
>
> index 1e497f0bb91..591acd2a7d2 100644
>
> --- a/gcc/flag-types.h
>
> +++ b/gcc/flag-types.h
>
> @@ -375,6 +375,13 @@ enum incremental_link {
>
> INCREMENTAL_LINK_LTO
>
> };
>
> +/* Kind of noreturn to ignore when reporting invalid noreturns */
>
> +enum class invalid_noreturn_kind {
>
> + NONE,
>
> + IMPLICIT,
>
> + EXPLICIT
>
> +};
>
> +
>
> /* Different trace modes. */
>
> enum sanitize_coverage_code {
>
> /* Trace PC. */
>
> diff --git a/gcc/opts.cc b/gcc/opts.cc
>
> index be90a632338..19d31c262d7 100644
>
> --- a/gcc/opts.cc
>
> +++ b/gcc/opts.cc
>
> @@ -2860,6 +2860,25 @@ common_handle_option (struct gcc_options *opts,
>
> dc->m_fatal_errors = value;
>
> break;
>
> + case OPT_Winvalid_noreturn_:
>
> + if (lang_mask == CL_DRIVER)
>
> + break;
>
> +
>
> + if (value)
>
> + warning (0, "%<-Winvalid-noreturn=%> is enabled by default,
> ignoring");
>
> + else if (strcmp (arg, "explicit"))
>
> + {
>
> + opts->x_flag_invalid_noreturn =
> invalid_noreturn_kind::EXPLICIT;
>
> + }
>
> + else if (strcmp (arg, "implicit"))
>
> + {
>
> + opts->x_flag_invalid_noreturn =
> invalid_noreturn_kind::IMPLICIT;
>
> + }
>
> + else
>
> + error_at (loc, "Unknown option for %<-Winvalid-noreturn=%>");
>
> +
>
> + break;
>
> +
>
> case OPT_Wstack_usage_:
>
> opts->x_flag_stack_usage_info = value != -1;
>
> break;
>
> diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
>
> index e6fd1294b95..f28dabc2bbf 100644
>
> --- a/gcc/tree-cfg.cc
>
> +++ b/gcc/tree-cfg.cc
>
> @@ -9820,7 +9820,8 @@ pass_warn_function_return::execute (function *fun)
>
> }
>
> if (location == UNKNOWN_LOCATION)
>
> location = cfun->function_end_locus;
>
> - warning_at (location, 0, "%<noreturn%> function does return");
>
> + if (flag_invalid_noreturn != invalid_noreturn_kind::IMPLICIT)
>
> + warning_at (location, 0, "%<noreturn%> function does return");
>
> }
>
> /* If we see "return;" in some basic block, then we do reach the end
>
> --
>
> 2.45.1
>
>
>
>
>
> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows
>
>
>
> *From: *Jason Merrill <ja...@redhat.com>
> *Sent: *Thursday, 18 July 2024 3:27 am
> *To: *Julian Waters <tanksherma...@gmail.com>; gcc-patches@gcc.gnu.org
> *Subject: *Re: [PATCH] c-family: Introduce the -Winvalid-noreturn flag
> from clang with extra tuneability
>
>
>
> On 7/9/24 6:46 AM, Julian Waters wrote:
>
> > Hi Jason,
>
> >
>
> > Sorry for the long period of radio silence, but I'm finally done with
>
> > all my university coursework. The main issue I see here is how to
>
> > process the Winvalid-noreturn= entry. Can I define it in c.opt and
>
> > then process it in c_common_handle_option and then store whether the
>
> > -W or -Wno form was used in a bool somewhere? If I can do that
>
> > somehow, and then access the bool at the callsites where it is
>
> > required, I can figure out the rest on my own
>
>
>
> You should be able to handle setting the variable entirely in c.opt,
>
> following the pattern of -fstrong-eval-order. The variable is defined
>
> by the Var(...) notation in c.opt, and the opts code handles setting it.
>
>
>
> > On Tue, Jun 11, 2024 at 10:26 AM Jason Merrill <ja...@redhat.com> wrote:
>
> >>
>
> >> On 6/10/24 03:13, Julian Waters wrote:
>
> >>> Hi Jason,
>
> >>>
>
> >>> Thanks for the reply. I'm a little bit overwhelmed with university at
>
> >>> the moment, would it be ok if I delay implementing this a little bit?
>
> >>
>
> >> Sure, we're still early in GCC 15 development, no time pressure.
>
> >>
>
> >>> On Tue, Jun 4, 2024 at 1:04 AM Jason Merrill <ja...@redhat.com> wrote:
>
> >>>>
>
> >>>> On 6/1/24 11:31, Julian Waters wrote:
>
> >>>>> Hi Jason,
>
> >>>>>
>
> >>>>> Thanks for the reply! I'll address your comments soon. I have a
>
> >>>>> question, if there is an option defined in c.opt as an Enum, like
>
> >>>>> fstrong-eval-order, and the -no variant of the option is passed,
> would
>
> >>>>> the Var somehow reflect the negated option? Eg
>
> >>>>>
>
> >>>>> Winvalid-noreturn=
>
> >>>>> C ObjC C++ ObjC++ Var(warn_invalid_noreturn) Joined
>
> >>>>> Enum(invalid_noreturn) Warning
>
> >>>>>
>
> >>>>> Enum
>
> >>>>> Name(invalid_noreturn) Type(int)
>
> >>>>>
>
> >>>>> EnumValue
>
> >>>>> Enum(invalid_noreturn) String(explicit) Value(0)
>
> >>>>
>
> >>>> -fstrong-eval-order has
>
> >>>>
>
> >>>> fstrong-eval-order
>
> >>>> C++ ObjC++ Common Alias(fstrong-eval-order=, all, none)
>
> >>>>
>
> >>>> to represent that plain -fstrong-eval-order is equivalent to
>
> >>>> -fstrong-eval-order=all, and -fno-strong-eval-order is equivalent to
> =none.
>
> >>>>
>
> >>>>> Would warn_invalid_noreturn then != 0 if
>
> >>>>> -Wno-invalid-noreturn=explicit is passed? Or is there a way to make a
>
> >>>>> warning call depend on 2 different OPT_ entries?
>
> >>>>
>
> >>>> Typically = options will specify RejectNegative so the driver will
>
> >>>> reject e.g. -Wno-invalid-noreturn=explicit.
>
> >>>>
>
> >>>> Jason
>
> >>>>
>
> >>>>> best regards,
>
> >>>>> Julian
>
> >>>>>
>
> >>>>> On Sat, Jun 1, 2024 at 4:57 AM Jason Merrill <ja...@redhat.com>
> wrote:
>
> >>>>>>
>
> >>>>>> On 5/29/24 09:58, Julian Waters wrote:
>
> >>>>>>> Currently, gcc warns about noreturn marked functions that return
> both explicitly and implicitly, with no way to turn this warning off. clang
> does have an option for these classes of warnings, -Winvalid-noreturn.
> However, we can do better. Instead of just having 1 option that switches
> the warnings for both on and off, we can define an extra layer of
> granularity, and have a separate options for implicit returns and explicit
> returns, as in -Winvalid-return=explicit and -Winvalid-noreturn=implicit.
> This patch adds both to gcc, for compatibility with clang.
>
> >>>>>>
>
> >>>>>> Thanks!
>
> >>>>>>
>
> >>>>>>> Do note that I am relatively new to gcc's codebase, and as such
> couldn't figure out how to cleanly define a general -Winvalid-noreturn
> warning that switch both on and off, for better compatibility with clang.
> If someone should point out how to do so, I'll happily rewrite my patch.
>
> >>>>>>
>
> >>>>>> See -fstrong-eval-order for an example of an option that can be used
>
> >>>>>> with or without =arg.
>
> >>>>>>
>
> >>>>>>> I also do not have write access to gcc, and will need help pushing
> this patch once the green light is given
>
> >>>>>>
>
> >>>>>> Good to know, I can take care of that.
>
> >>>>>>
>
> >>>>>>> best regards,
>
> >>>>>>> Julian
>
> >>>>>>>
>
> >>>>>>> gcc/c-family/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * c.opt: Introduce -Winvalid-noreturn=explicit and
> -Winvalid-noreturn=implicit
>
> >>>>>>>
>
> >>>>>>> gcc/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * tree-cfg.cc (pass_warn_function_return::execute): Use it
>
> >>>>>>>
>
> >>>>>>> gcc/c/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * c-typeck.cc (c_finish_return): Use it
>
> >>>>>>> * gimple-parser.cc (c_finish_gimple_return): Use it
>
> >>>>>>>
>
> >>>>>>> gcc/config/mingw/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * mingw32.h (EXTRA_OS_CPP_BUILTINS): Fix semicolons
>
> >>>>>>>
>
> >>>>>>> gcc/cp/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * coroutines.cc (finish_co_return_stmt): Use it
>
> >>>>>>> * typeck.cc (check_return_expr): Use it
>
> >>>>>>>
>
> >>>>>>> gcc/doc/ChangeLog:
>
> >>>>>>>
>
> >>>>>>> * invoke.texi: Document new options
>
> >>>>>>>
>
> >>>>>>> From 4daf884f8bbc1e318ba93121a6fdf4139da80b64 Mon Sep 17
> 00:00:00 2001
>
> >>>>>>> From: TheShermanTanker <tanksherma...@gmail.com>
>
> >>>>>>> Date: Wed, 29 May 2024 21:32:08 +0800
>
> >>>>>>> Subject: [PATCH] Introduce the -Winvalid-noreturn flag from clang
> with extra
>
> >>>>>>> tuneability
>
> >>>>>>
>
> >>>>>> The rationale and ChangeLog entries should be part of the commit
> message
>
> >>>>>> (and so the git format-patch output).
>
> >>>>>>
>
> >>>>>>>
>
> >>>>>>> Signed-off-by: TheShermanTanker <tanksherma...@gmail.com>
>
> >>>>>>
>
> >>>>>> A DCO sign-off can't use a pseudonym, sorry; please either sign off
>
> >>>>>> using your real name or file a copyright assignment for the
> pseudonym
>
> >>>>>> with the FSF.
>
> >>>>>>
>
> >>>>>> See https://gcc.gnu.org/contribute.html#legal for more detail.
>
> >>>>>>
>
> >>>>>>> ---
>
> >>>>>>> gcc/c-family/c.opt | 8 ++++++++
>
> >>>>>>> gcc/c/c-typeck.cc | 2 +-
>
> >>>>>>> gcc/c/gimple-parser.cc | 2 +-
>
> >>>>>>> gcc/config/mingw/mingw32.h | 6 +++---
>
> >>>>>>> gcc/cp/coroutines.cc | 2 +-
>
> >>>>>>> gcc/cp/typeck.cc | 2 +-
>
> >>>>>>> gcc/doc/invoke.texi | 13 +++++++++++++
>
> >>>>>>> gcc/tree-cfg.cc | 2 +-
>
> >>>>>>> 8 files changed, 29 insertions(+), 8 deletions(-)
>
> >>>>>>>
>
> >>>>>>> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
>
> >>>>>>> index fb34c3b7031..32a2859fdcc 100644
>
> >>>>>>> --- a/gcc/c-family/c.opt
>
> >>>>>>> +++ b/gcc/c-family/c.opt
>
> >>>>>>> @@ -886,6 +886,14 @@ Winvalid-constexpr
>
> >>>>>>> C++ ObjC++ Var(warn_invalid_constexpr) Init(-1) Warning
>
> >>>>>>> Warn when a function never produces a constant expression.
>
> >>>>>>>
>
> >>>>>>> +Winvalid-noreturn=explicit
>
> >>>>>>> +C ObjC C++ ObjC++ Warning
>
> >>>>>>> +Warn when a function marked noreturn returns explicitly.
>
> >>>>>>> +
>
> >>>>>>> +Winvalid-noreturn=implicit
>
> >>>>>>> +C ObjC C++ ObjC++ Warning
>
> >>>>>>> +Warn when a function marked noreturn returns implicitly.
>
> >>>>>>> +
>
> >>>>>>> Winvalid-offsetof
>
> >>>>>>> C++ ObjC++ Var(warn_invalid_offsetof) Init(1) Warning
>
> >>>>>>> Warn about invalid uses of the \"offsetof\" macro.
>
> >>>>>>> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
>
> >>>>>>> index ad4c7add562..1941fbc44cb 100644
>
> >>>>>>> --- a/gcc/c/c-typeck.cc
>
> >>>>>>> +++ b/gcc/c/c-typeck.cc
>
> >>>>>>> @@ -11468,7 +11468,7 @@ c_finish_return (location_t loc, tree
> retval, tree origtype)
>
> >>>>>>> location_t xloc =
> expansion_point_location_if_in_system_header (loc);
>
> >>>>>>>
>
> >>>>>>> if (TREE_THIS_VOLATILE (current_function_decl))
>
> >>>>>>> - warning_at (xloc, 0,
>
> >>>>>>> + warning_at (xloc, OPT_Winvalid_noreturn_explicit,
>
> >>>>>>> "function declared %<noreturn%> has a %<return%>
> statement");
>
> >>>>>>>
>
> >>>>>>> if (retval)
>
> >>>>>>> diff --git a/gcc/c/gimple-parser.cc b/gcc/c/gimple-parser.cc
>
> >>>>>>> index d156d83cd37..1acaf75f844 100644
>
> >>>>>>> --- a/gcc/c/gimple-parser.cc
>
> >>>>>>> +++ b/gcc/c/gimple-parser.cc
>
> >>>>>>> @@ -2593,7 +2593,7 @@ c_finish_gimple_return (location_t loc, tree
> retval)
>
> >>>>>>> location_t xloc =
> expansion_point_location_if_in_system_header (loc);
>
> >>>>>>>
>
> >>>>>>> if (TREE_THIS_VOLATILE (current_function_decl))
>
> >>>>>>> - warning_at (xloc, 0,
>
> >>>>>>> + warning_at (xloc, OPT_Winvalid_noreturn_explicit,
>
> >>>>>>> "function declared %<noreturn%> has a %<return%>
> statement");
>
> >>>>>>>
>
> >>>>>>> if (! retval)
>
> >>>>>>> diff --git a/gcc/config/mingw/mingw32.h
> b/gcc/config/mingw/mingw32.h
>
> >>>>>>> index fa6e307476c..a69926133b1 100644
>
> >>>>>>> --- a/gcc/config/mingw/mingw32.h
>
> >>>>>>> +++ b/gcc/config/mingw/mingw32.h
>
> >>>>>>> @@ -35,9 +35,9 @@ along with GCC; see the file COPYING3. If not
> see
>
> >>>>>>> | MASK_MS_BITFIELD_LAYOUT)
>
> >>>>>>>
>
> >>>>>>> #ifdef TARGET_USING_MCFGTHREAD
>
> >>>>>>> -#define DEFINE_THREAD_MODEL builtin_define
> ("__USING_MCFGTHREAD__");
>
> >>>>>>> +#define DEFINE_THREAD_MODEL builtin_define
> ("__USING_MCFGTHREAD__")
>
> >>>>>>> #elif defined(TARGET_USE_PTHREAD_BY_DEFAULT)
>
> >>>>>>> -#define DEFINE_THREAD_MODEL builtin_define
> ("__USING_POSIXTHREAD__");
>
> >>>>>>> +#define DEFINE_THREAD_MODEL builtin_define
> ("__USING_POSIXTHREAD__")
>
> >>>>>>> #else
>
> >>>>>>> #define DEFINE_THREAD_MODEL
>
> >>>>>>> #endif
>
> >>>>>>> @@ -60,7 +60,7 @@ along with GCC; see the file COPYING3. If not
> see
>
> >>>>>>> builtin_define_std ("WIN64"); \
>
> >>>>>>> builtin_define ("_WIN64"); \
>
> >>>>>>> } \
>
> >>>>>>> - DEFINE_THREAD_MODEL \
>
> >>>>>>> + DEFINE_THREAD_MODEL; \
>
> >>>>>>>
> } \
>
> >>>>>>> while (0)
>
> >>>>>>>
>
> >>>>>>> diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
>
> >>>>>>> index 97bc211ff67..53e56bd4959 100644
>
> >>>>>>> --- a/gcc/cp/coroutines.cc
>
> >>>>>>> +++ b/gcc/cp/coroutines.cc
>
> >>>>>>> @@ -1375,7 +1375,7 @@ finish_co_return_stmt (location_t kw, tree
> expr)
>
> >>>>>>>
>
> >>>>>>> /* Makes no sense for a co-routine really. */
>
> >>>>>>> if (TREE_THIS_VOLATILE (current_function_decl))
>
> >>>>>>> - warning_at (kw, 0,
>
> >>>>>>> + warning_at (kw, OPT_Winvalid_noreturn_explicit,
>
> >>>>>>> "function declared %<noreturn%> has a"
>
> >>>>>>> " %<co_return%> statement");
>
> >>>>>>>
>
> >>>>>>> diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
>
> >>>>>>> index 1b7a31d32f3..74cc59bfb87 100644
>
> >>>>>>> --- a/gcc/cp/typeck.cc
>
> >>>>>>> +++ b/gcc/cp/typeck.cc
>
> >>>>>>> @@ -11062,7 +11062,7 @@ check_return_expr (tree retval, bool
> *no_warning, bool *dangling)
>
> >>>>>>> (This is a G++ extension, used to get better code for
> functions
>
> >>>>>>> that call the `volatile' function.) */
>
> >>>>>>> if (TREE_THIS_VOLATILE (current_function_decl))
>
> >>>>>>> - warning (0, "function declared %<noreturn%> has a %<return%>
> statement");
>
> >>>>>>> + warning (OPT_Winvalid_noreturn_explicit, "function declared
> %<noreturn%> has a %<return%> statement");
>
> >>>>>>>
>
> >>>>>>> /* Check for various simple errors. */
>
> >>>>>>> if (DECL_DESTRUCTOR_P (current_function_decl))
>
> >>>>>>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
>
> >>>>>>> index 2cba380718b..27d880fd4f0 100644
>
> >>>>>>> --- a/gcc/doc/invoke.texi
>
> >>>>>>> +++ b/gcc/doc/invoke.texi
>
> >>>>>>> @@ -376,6 +376,7 @@ Objective-C and Objective-C++ Dialects}.
>
> >>>>>>> -Winfinite-recursion
>
> >>>>>>> -Winit-self -Winline -Wno-int-conversion
> -Wint-in-bool-context
>
> >>>>>>> -Wno-int-to-pointer-cast -Wno-invalid-memory-model
>
> >>>>>>> +-Winvalid-noreturn=explicit -Winvalid-noreturn=implicit
>
> >>>>>>> -Winvalid-pch -Winvalid-utf8 -Wno-unicode
> -Wjump-misses-init
>
> >>>>>>> -Wlarger-than=@var{byte-size} -Wlogical-not-parentheses
> -Wlogical-op
>
> >>>>>>> -Wlong-long -Wno-lto-type-mismatch -Wmain
> -Wmaybe-uninitialized
>
> >>>>>>> @@ -10482,6 +10483,18 @@ an error. @option{Wint-to-pointer-cast}
> is enabled by default.
>
> >>>>>>> Suppress warnings from casts from a pointer to an integer
> type of a
>
> >>>>>>> different size.
>
> >>>>>>>
>
> >>>>>>> +@opindex Winvalid-noreturn=explicit
>
> >>>>>>> +@opindex Wno-invalid-noreturn=explicit
>
> >>>>>>> +@item -Winvalid-noreturn=explicit
>
> >>>>>>> +Warn if a function marked noreturn returns explicitly, that is, it
>
> >>>>>>> +contains a return statement.
>
> >>>>>>> +
>
> >>>>>>> +@opindex Winvalid-noreturn=implicit
>
> >>>>>>> +@opindex Wno-invalid-noreturn=implicit
>
> >>>>>>> +@item -Winvalid-noreturn=implicit
>
> >>>>>>> +Warn if a function marked noreturn returns implicitly, that is, it
>
> >>>>>>> +has a path in its control flow that can reach the end of its body.
>
> >>>>>>> +
>
> >>>>>>> @opindex Winvalid-pch
>
> >>>>>>> @opindex Wno-invalid-pch
>
> >>>>>>> @item -Winvalid-pch
>
> >>>>>>> diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
>
> >>>>>>> index 7fb7b92966b..cfe91038dd1 100644
>
> >>>>>>> --- a/gcc/tree-cfg.cc
>
> >>>>>>> +++ b/gcc/tree-cfg.cc
>
> >>>>>>> @@ -9817,7 +9817,7 @@ pass_warn_function_return::execute (function
> *fun)
>
> >>>>>>> }
>
> >>>>>>> if (location == UNKNOWN_LOCATION)
>
> >>>>>>> location = cfun->function_end_locus;
>
> >>>>>>> - warning_at (location, 0, "%<noreturn%> function does
> return");
>
> >>>>>>> + warning_at (location, OPT_Winvalid_noreturn_implicit,
> "%<noreturn%> function does return");
>
> >>>>>>> }
>
> >>>>>>>
>
> >>>>>>> /* If we see "return;" in some basic block, then we do
> reach the end
>
> >>>>>>
>
> >>>>>
>
> >>>>
>
> >>>
>
> >>
>
> >
>
>
>
>
>
