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From: Tom de Vries <tdevries@suse.de>
To: Tsukasa OI <research_trasio@irq.a4lg.com>,
	Andrew Burgess <aburgess@redhat.com>,
	Mike Frysinger <vapier@gentoo.org>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH v3 4/5] sim: Check known getopt definition existence
Date: Wed, 12 Oct 2022 18:28:36 +0200	[thread overview]
Message-ID: <7b235ccb-ab2e-cba0-3015-2eae5fe6a8a4@suse.de> (raw)
In-Reply-To: <a57b2a3460064a9adc95914ba21214c8dbfc2bbf.1665038297.git.research_trasio@irq.a4lg.com>

On 10/6/22 08:43, Tsukasa OI via Gdb-patches wrote:
> Clang generates a warning if there is a function declaration/definition
> with zero arguments.  Such declarations/definitions without a prototype (an
> argument list) are deprecated forms of indefinite arguments
> ("-Wdeprecated-non-prototype").  On the default configuration, it causes a
> build failure (unless "--disable-werror" is specified).
> 
> include/getopt.h defines some getopt function definitions but one of them
> has a form "extern int getopt ();".  If this form is selected in
> include/getopt.h, Clang generates a warning and the build fails by default.
> 
> In really old environments, this getopt definition with no arguments is
> necessary (because the definition may change between environments).
> However, this definition is now a cause of problems on modern environments.
> 
> A good news is, this definition is not always selected (e.g. if used by
> binutils/*.c).  This is because configuration scripts of binutils, gas,
> gprof and ld tries to find known definition of getopt function is used and
> defines HAVE_DECL_GETOPT macro.  If this macro is defined when getopt.h is
> included, a good form of getopt is used and Clang won't generate warnings.
> 
> This commit adds a modified portion of ld/configure.ac to find the known
> getopt definition.  If we could find one (and we *will* in most modern
> environments), we don't need to rely on the deprecated definition.

I'm guessing this cause the build breakage on buildbot gdb-centos-x86_64 .

https://builder.sourceware.org/buildbot/#/builders/71/builds/1392

Thanks,
- Tom


> ---
>   sim/config.h.in  |  3 +++
>   sim/configure    | 32 ++++++++++++++++++++++++++++++++
>   sim/configure.ac | 10 ++++++++++
>   3 files changed, 45 insertions(+)
> 
> diff --git a/sim/config.h.in b/sim/config.h.in
> index 84c363c0aec..9a94b289e46 100644
> --- a/sim/config.h.in
> +++ b/sim/config.h.in
> @@ -41,6 +41,9 @@
>   /* Define to 1 if you have the `chmod' function. */
>   #undef HAVE_CHMOD
>   
> +/* Is the prototype for getopt in <unistd.h> in the expected format? */
> +#undef HAVE_DECL_GETOPT
> +
>   /* Define to 1 if you have the declaration of `tzname', and to 0 if you don't.
>      */
>   #undef HAVE_DECL_TZNAME
> diff --git a/sim/configure b/sim/configure
> index 75d1935df38..dac7f085be1 100755
> --- a/sim/configure
> +++ b/sim/configure
> @@ -16428,6 +16428,38 @@ $as_echo "${WARN_CFLAGS} ${WERROR_CFLAGS}" >&6; }
>   fi
>   
>   
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for a known getopt prototype in unistd.h" >&5
> +$as_echo_n "checking for a known getopt prototype in unistd.h... " >&6; }
> +if ${sim_cv_decl_getopt_unistd_h+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h.  */
> +#include <unistd.h>
> +int
> +main ()
> +{
> +extern int getopt (int, char *const*, const char *);
> +  ;
> +  return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> +  sim_cv_decl_getopt_unistd_h=yes
> +else
> +  sim_cv_decl_getopt_unistd_h=no
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +fi
> +
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $sim_cv_decl_getopt_unistd_h" >&5
> +$as_echo "$sim_cv_decl_getopt_unistd_h" >&6; }
> +if test $sim_cv_decl_getopt_unistd_h = yes; then
> +
> +$as_echo "#define HAVE_DECL_GETOPT 1" >>confdefs.h
> +
> +fi
> +
>   
>   
>   
> diff --git a/sim/configure.ac b/sim/configure.ac
> index 66a1020efe0..be0cfdbea32 100644
> --- a/sim/configure.ac
> +++ b/sim/configure.ac
> @@ -177,6 +177,16 @@ SIM_AC_OPTION_STDIO
>   SIM_AC_OPTION_TRACE
>   SIM_AC_OPTION_WARNINGS
>   
> +AC_MSG_CHECKING(for a known getopt prototype in unistd.h)
> +AC_CACHE_VAL(sim_cv_decl_getopt_unistd_h,
> +[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <unistd.h>], [extern int getopt (int, char *const*, const char *);])],
> +sim_cv_decl_getopt_unistd_h=yes, sim_cv_decl_getopt_unistd_h=no)])
> +AC_MSG_RESULT($sim_cv_decl_getopt_unistd_h)
> +if test $sim_cv_decl_getopt_unistd_h = yes; then
> +  AC_DEFINE([HAVE_DECL_GETOPT], 1,
> +	    [Is the prototype for getopt in <unistd.h> in the expected format?])
> +fi
> +
>   dnl These are unfortunate.  They are conditionally called by other sim macros
>   dnl but always used by common/Make-common.in.  So we have to subst here even
>   dnl when the rest of the code is in the respective macros.  Once we merge the

  reply	other threads:[~2022-10-12 16:28 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-13 12:57 [PATCH 0/4] sim/common: Suppress warnings if built with Clang Tsukasa OI
2022-09-13 12:57 ` [PATCH 1/4] sim: Add ATTRIBUTE_PRINTF Tsukasa OI
2022-09-13 12:57 ` [PATCH 2/4] sim: Remove self-assignments Tsukasa OI
2022-09-13 12:57 ` [PATCH 3/4] sim: Make WITH_{TRACE,PROFILE}-based macros bool Tsukasa OI
2022-10-05 11:38   ` Andrew Burgess
2022-10-06  5:33     ` Tsukasa OI
2022-09-13 12:57 ` [PATCH 4/4] sim: Suppress non-literal printf warning Tsukasa OI
2022-10-05 11:45   ` Andrew Burgess
2022-10-06  5:39     ` Tsukasa OI
2022-10-23 12:22       ` Mike Frysinger
2022-10-24 10:50         ` Tsukasa OI
2022-09-25  8:42 ` [PATCH v2 0/5] sim: Suppress warnings if built with Clang Tsukasa OI
2022-09-25  8:42   ` [PATCH v2 1/5] sim: Remove self-assignments Tsukasa OI
2022-09-25  8:42   ` [PATCH v2 2/5] sim: Make WITH_{TRACE,PROFILE}-based macros bool Tsukasa OI
2022-09-25  8:42   ` [PATCH v2 3/5] sim: Suppress non-literal printf warning Tsukasa OI
2022-09-25  8:42   ` [PATCH v2 4/5] sim: Check known getopt definition existence Tsukasa OI
2022-09-25  8:42   ` [PATCH v2 5/5] sim: Initialize pbb_br_* by default Tsukasa OI
2022-10-06  6:43   ` [PATCH v3 0/5] sim: Suppress warnings if built with Clang Tsukasa OI
2022-10-06  6:43     ` [PATCH v3 1/5] sim: Remove self-assignments Tsukasa OI
2022-10-11 14:21       ` Andrew Burgess
2022-10-11 14:29         ` Tsukasa OI
2022-10-06  6:43     ` [PATCH v3 2/5] sim: Make WITH_{TRACE,PROFILE}-based macros bool Tsukasa OI
2022-10-06  6:43     ` [PATCH v3 3/5] sim: Suppress non-literal printf warning Tsukasa OI
2022-10-11 14:22       ` Andrew Burgess
2022-10-06  6:43     ` [PATCH v3 4/5] sim: Check known getopt definition existence Tsukasa OI
2022-10-12 16:28       ` Tom de Vries [this message]
2022-10-12 17:03         ` Tsukasa OI
2022-10-12 17:08           ` Tom de Vries
2022-10-12 17:20             ` Tom de Vries
2022-10-13  9:50         ` Tsukasa OI
2022-10-23 12:16       ` Mike Frysinger
2022-10-27  2:02         ` Tsukasa OI
2023-01-03  3:12           ` Mike Frysinger
2023-01-03  8:47             ` Tsukasa OI
2022-10-06  6:43     ` [PATCH v3 5/5] sim: Initialize pbb_br_* by default Tsukasa OI
2022-10-11 14:20     ` [PATCH v3 0/5] sim: Suppress warnings if built with Clang Andrew Burgess
2022-10-11 16:40     ` Tom de Vries
2022-10-11 18:02       ` Tsukasa OI

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