Re: Turn on compiler warnings by default for AC_PROG_CC, AC_PROG_CXX & AC_PROG_FC
Dale Visser <[email protected]>
| Newsgroups | gmane.comp.sysutils.autoconf.patches |
|---|---|
| Message-ID | <CALr3GuZZRW+1oY_pat4UbRfzume6My1ECzyrwLsrHX_FaOB4AQ@mail.gmail.com> |
My apologies. I just realized that I submitted a commit-by-commit patch,
when I just wanted to share the overall diff. Please use the following as
the basis for discussion:
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index a2368e7..87c70fb 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7160,7 +7160,7 @@ makes this invalid. That is why Autoconf stopped
issuing
@end table
@anchor{AC_PROG_CC}
-@defmac AC_PROG_CC (@ovar{compiler-search-list})
+@defmac AC_PROG_CC (@ovar{compiler-search-list}, @dots{})
@acindex{PROG_CC}
@evindex CC
@evindex CFLAGS
@@ -7213,6 +7213,15 @@ other compilers. If your package does not like this
default, then it is
acceptable to insert the line @samp{: $@{CFLAGS=""@}} after @code{AC_INIT}
and before @code{AC_PROG_CC} to select an empty default instead.
+Scan for common flags that enable compiler warnings. If found, append them
+to @code{CFLAGS}. To modify this behaviour, for example, to restore the old
+no-warning-flag behaviour, add parameters which will get shifted by 1,
+and passed on to @code{AC_FLAGS_WARN_ALL}.
+
+@example
+AC_PROG_CC([], [], [], [echo No warning flags please.])
+@end example
+
Many Autoconf macros use a compiler, and thus call
@samp{AC_REQUIRE([AC_PROG_CC])} to ensure that the compiler has been
determined before the body of the outermost @code{AC_DEFUN} macro.
@@ -7537,7 +7546,7 @@ compiler fix the header files automatically when
installed.
@subsection C++ Compiler Characteristics
-@defmac AC_PROG_CXX (@ovar{compiler-search-list})
+@defmac AC_PROG_CXX (@ovar{compiler-search-list}, @dots{})
@acindex{PROG_CXX}
@evindex CXX
@evindex CXXFLAGS
@@ -7599,6 +7608,16 @@ systems where G++ does not accept @option{-g}), or
@option{-g} for other
compilers. If your package does not like this default, then it is
acceptable to insert the line @samp{: $@{CXXFLAGS=""@}} after
@code{AC_INIT}
and before @code{AC_PROG_CXX} to select an empty default instead.
+
+Scan for common flags that enable compiler warnings. If found, append them
+to @code{CXXFLAGS}. To modify this behaviour, for example, to restore the
old
+no-warning-flag behaviour, add parameters which will get shifted by 1,
+and passed on to @code{AC_FLAGS_WARN_ALL}.
+
+@example
+AC_PROG_CXX([], [], [], [echo No warning flags please.])
+@end example
+
@end defmac
@defmac AC_PROG_CXXCPP
@@ -7825,7 +7844,7 @@ The result of the GNU test is cached in the
@code{ac_cv_prog_f77_g} variable.
@end defmac
-@defmac AC_PROG_FC (@ovar{compiler-search-list}, @ovar{dialect})
+@defmac AC_PROG_FC (@ovar{compiler-search-list}, @ovar{dialect}, @dots{})
@acindex{PROG_FC}
@evindex FC
@evindex FCFLAGS
@@ -7863,6 +7882,17 @@ set @code{FCFLAGS} to @option{-g} for all other
Fortran compilers.
The result of the GNU test is cached in the @code{ac_cv_fc_compiler_gnu}
variable, acceptance of @option{-g} in the @code{ac_cv_prog_fc_g}
variable.
+
+Scan for common flags that enable compiler warnings. If found, append them
+to @code{FCFLAGS}. To modify this behaviour, for example, to restore the
old
+no-warning-flag behaviour, add parameters which will get shifted by 2,
+and passed on to @code{AC_FLAGS_WARN_ALL}.
+
+@example
+AC_PROG_FC([], [], [], [], [echo No warning flags please.])
+@end example
+
+
@end defmac
@defmac AC_PROG_F77_C_O
@@ -23427,6 +23457,71 @@ The current language does not change.
@code{AC_LANG_PUSH} is preferred
(@pxref{AC_LANG_PUSH}).
@end defmac
+@anchor{AC_CFLAGS_WARN_ALL}
+@defmac AC_CFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
@var{add-value-if-not-found}, @var{action-if-found},
@var{action-if-not-found})
+@acindex{CFLAGS_WARN_ALL}
+Try to find a C compiler option that enables most reasonable warnings. See
+@pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters. The
most
+typical usage is shown below.
+
+@example
+AC_CFLAGS_WARN_ALL
+@end example
+@end defmac
+
+@anchor{AC_CXXFLAGS_WARN_ALL}
+@defmac AC_CXXFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
@var{add-value-if-not-found}, @var{action-if-found},
@var{action-if-not-found})
+@acindex{CXXFLAGS_WARN_ALL}
+Try to find a C++ compiler option that enables most reasonable warnings.
See
+@pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters. The
most
+typical usage is shown below.
+
+@example
+AC_CXXFLAGS_WARN_ALL
+@end example
+@end defmac
+
+@anchor{AC_FCFLAGS_WARN_ALL}
+@defmac AC_FCFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
@var{add-value-if-not-found}, @var{action-if-found},
@var{action-if-not-found})
+@acindex{FCFLAGS_WARN_ALL}
+Try to find a Fortran compiler option that enables most reasonable
warnings.
+See @pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters.
The most
+typical usage is shown below.
+
+@example
+AC_FCFLAGS_WARN_ALL
+@end example
+@end defmac
+
+@anchor{AC_FLAGS_WARN_ALL}
+@defmac AC_FLAGS_WARN_ALL(@var{shell-variable-to-add-to},
@var{add-value-if-not-found}, @var{action-if-found},
@var{action-if-not-found})
+@acindex{FLAGS_WARN_ALL}
+Try to find a compiler option that enables most reasonable warnings.
+
+Usually not used directly. Instead, use @pxref{AC_CFLAGS_WARN_ALL},
+@pxref{AC_CXXFLAGS_WARN_ALL}, or @pxref{AC_FCFLAGS_WARN_ALL}, all of which
perform
+a requisite @pxref{AC_LANG_PUSH}, and then invoke this macro without
altering any
+positional parameters they were provided.
+
+The first positional parameter defines the shell variable to use, and
+if not provided, depends on @pxref{AC_LANG_PUSH} having been invoked
properly.
+If appropriate warning flag values can be automatically determined for the
+compiler, then the third positional parameter (if present) defines an
+alternate action to take instead of appending to the shell variable. If no
+appropriate warning flag values could be determined, then the second
+positional parameter (if present) defines alternate flags to append to the
+shell variable, unless the fourth positional parameter is present, in which
+case it defines an alternate action to take instead of appending to the
shell
+variable.
+@end defmac
+
+@defmac AC_APPEND_FLAG(@var{add-value})
+@acindex{APPEND_FLAG}
+Used internally by @pxref{AC_FLAGS_WARN_ALL}. Behavior is to append the
given to
+the shell variable determined or provided in the call to
+@pxref{AC_FLAGS_WARN_ALL}, but only if it is not already present there.
+@end defmac
+
@defmac AC_LINK_FILES (@var{source}@dots{}, @var{dest}@dots{})
@acindex{LINK_FILES}
This is an obsolete version of @code{AC_CONFIG_LINKS}
diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index 25780f9..c018c92 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -424,11 +424,17 @@ AU_DEFUN([ac_cv_prog_gcc],
[ac_cv_c_compiler_gnu])
-# AC_PROG_CC([COMPILER ...])
+# AC_PROG_CC([COMPILER ...], ...)
# --------------------------
# COMPILER ... is a space separated list of C compilers to search for.
# This just gives the user an opportunity to specify an alternative
# search list for the C compiler.
+# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
+# are no extra parameters, then compiler warnings will be turned on. An
+# example of how to avoid this is invoking
+# AC_PROG_CC([COMPILER ...], [], [], [echo No extra warnings please.])
+# Where the final parameter is providing an alternate action to enabling
+# warning flags.
AN_MAKEVAR([CC], [AC_PROG_CC])
AN_PROGRAM([cc], [AC_PROG_CC])
AN_PROGRAM([gcc], [AC_PROG_CC])
@@ -491,6 +497,7 @@ _AC_PROG_CC_C11([ac_prog_cc_stdc=c11
[ac_prog_cc_stdc=no
ac_cv_prog_cc_stdc=no])])])
dnl
+AC_FLAGS_WARN_ALL(m4_shift($@))
AC_LANG_POP(C)dnl
])# AC_PROG_CC
@@ -674,7 +681,7 @@ AU_DEFUN([ac_cv_prog_gxx],
[ac_cv_cxx_compiler_gnu])
-# AC_PROG_CXX([LIST-OF-COMPILERS])
+# AC_PROG_CXX([LIST-OF-COMPILERS], ...)
# --------------------------------
# LIST-OF-COMPILERS is a space separated list of C++ compilers to search
# for (if not specified, a default list is used). This just gives the
@@ -686,6 +693,12 @@ AU_DEFUN([ac_cv_prog_gxx],
# RCC Rational C++
# xlC_r AIX C Set++ (with support for reentrant code)
# xlC AIX C Set++
+# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
+# are no extra parameters, then compiler warnings will be turned on. An
+# example of how to avoid this is invoking
+# AC_PROG_CXX([LIST-OF-COMPILERS], [], [], [echo No extra warnings
please.])
+# Where the final parameter is providing an alternate action to enabling
+# warning flags.
AN_MAKEVAR([CXX], [AC_PROG_CXX])
AN_PROGRAM([CC], [AC_PROG_CXX])
AN_PROGRAM([c++], [AC_PROG_CXX])
@@ -732,6 +745,7 @@ _AC_PROG_CXX_CXX11([ac_prog_cxx_stdcxx=cxx11
ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98],
[ac_prog_cxx_stdcxx=no
ac_cv_prog_cxx_stdcxx=no])])
+AC_FLAGS_WARN_ALL(m4_shift($@))
AC_LANG_POP(C++)dnl
])# AC_PROG_CXX
diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
index f20b029..8280e48 100644
--- a/lib/autoconf/fortran.m4
+++ b/lib/autoconf/fortran.m4
@@ -371,10 +371,16 @@ AC_LANG_POP(Fortran 77)dnl
])# AC_PROG_F77
-# AC_PROG_FC([COMPILERS...], [DIALECT])
+# AC_PROG_FC([COMPILERS...], [DIALECT], ...)
# -------------------------------------
# COMPILERS is a space separated list of Fortran 77 compilers to search
# for, and [DIALECT] is an optional dialect. See also _AC_PROG_FC.
+# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
+# are no extra parameters, then compiler warnings will be turned on. An
+# example of how to avoid this is invoking
+# AC_PROG_FC([COMPILERS...], [DIALECT], [], [], [echo No extra warnings
please.])
+# Where the final parameter is providing an alternate action to enabling
+# warning flags.
AC_DEFUN([AC_PROG_FC],
[AC_LANG_PUSH(Fortran)dnl
AC_ARG_VAR([FC], [Fortran compiler command])dnl
@@ -387,6 +393,7 @@ if test $ac_compiler_gnu = yes; then
else
GFC=
fi
+AC_FLAGS_WARN_ALL(m4_shift2($@))
AC_LANG_POP(Fortran)dnl
])# AC_PROG_FC
diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
index c99f152..0c86b63 100644
--- a/lib/autoconf/lang.m4
+++ b/lib/autoconf/lang.m4
@@ -719,3 +719,139 @@ ac_objext=$OBJEXT
AC_DEFUN([AC_LANG_WERROR],
[m4_divert_text([DEFAULTS], [ac_[]_AC_LANG_ABBREV[]_werror_flag=])
ac_[]_AC_LANG_ABBREV[]_werror_flag=yes])# AC_LANG_WERROR
+
+#
+# SYNOPSIS
+#
+# AC_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
+#
+# DESCRIPTION
+#
+# FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
+# added in between.
+#
+# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+# CFLAGS) is used. FLAGS-VARIABLE is not changed if it already contains
+# FLAG. If FLAGS-VARIABLE is unset in the shell, it is set to exactly
+# FLAG.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
+# NOTE: Copied from AX_APPEND_FLAG in autoconf-archive, which had
copyright
+# assigned as follows:
+#
+# Copyright (c) 2008 Guido U. Draheim <[email protected]>
+# Copyright (c) 2011 Maarten Bosmans <[email protected]>
+#
+
+#serial 2
+
+AC_DEFUN([AC_APPEND_FLAG],
+[AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])dnl
+AS_VAR_SET_IF(FLAGS,
+ [case " AS_VAR_GET(FLAGS) " in
+ *" $1 "*)
+ AC_RUN_LOG([: FLAGS already contains $1])
+ ;;
+ *)
+ AC_RUN_LOG([: FLAGS="$FLAGS $1"])
+ AS_VAR_SET(FLAGS, ["AS_VAR_GET(FLAGS) $1"])
+ ;;
+ esac],
+ [AS_VAR_SET(FLAGS,["$1"])])
+AS_VAR_POPDEF([FLAGS])dnl
+])dnl AC_APPEND_FLAG
+
+#
+# SYNOPSIS
+#
+# AC_CFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
+# AC_CXXFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
+# AC_FCFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
+#
+# DESCRIPTION
+#
+# Try to find a compiler option that enables most reasonable warnings.
+#
+# For the GNU compiler it will be -Wall (and -ansi -pedantic) The result
+# is added to the shellvar being CFLAGS, CXXFLAGS, or FCFLAGS by default.
+#
+# Currently this macro knows about the GCC, Solaris, Digital Unix, AIX,
+# HP-UX, IRIX, NEC SX-5 (Super-UX 10), Cray J90 (Unicos 10.0.0.8), and
+# Intel compilers. For a given compiler, the Fortran flags are much more
+# experimental than their C equivalents.
+#
+# - $1 shell-variable-to-add-to : CFLAGS, CXXFLAGS, or FCFLAGS
+# - $2 add-value-if-not-found : nothing
+# - $3 action-if-found : add value to shellvariable
+# - $4 action-if-not-found : nothing
+#
+# NOTE: These macros depend on AX_APPEND_FLAG.
+# NOTE: Based upon AX_*FLAGS_WARN_ALL from autoconf-archive, which had
+# copyright assigned as follows:
+#
+# Copyright (c) 2008 Guido U. Draheim <[email protected]>
+# Copyright (c) 2010 Rhys Ulerich <[email protected]>
+#
+
+#serial 14
+
+AC_DEFUN([AC_FLAGS_WARN_ALL],[dnl
+AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
+AS_VAR_PUSHDEF([VAR],[ac_cv_[]_AC_LANG_ABBREV[]flags_warn_all])dnl
+AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for maximum warnings],
+VAR,[VAR="no, unknown"
+ac_save_[]FLAGS="$[]FLAGS"
+for ac_arg dnl
+in "-warn all % -warn all" dnl Intel
+ "-pedantic % -Wall" dnl GCC
+ "-xstrconst % -v" dnl Solaris C
+ "-std1 % -verbose -w0 -warnprotos" dnl Digital Unix
+ "-qlanglvl=ansi % -qsrcmsg -qinfo=all:noppt:noppc:noobs:nocnd" dnl AIX
+ "-ansi -ansiE % -fullwarn" dnl IRIX
+ "+ESlit % +w1" dnl HP-UX C
+ "-Xc % -pvctl[,]fullmsg" dnl NEC SX-5 (Super-UX 10)
+ "-h conform % -h msglevel 2" dnl Cray C (Unicos)
+ #
+do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
+ _AC_COMPILE_IFELSE([AC_LANG_PROGRAM],
+ [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
+done
+FLAGS="$ac_save_[]FLAGS"
+])
+AS_VAR_POPDEF([FLAGS])dnl
+AC_REQUIRE([AC_APPEND_FLAG])
+case ".$VAR" in
+ .ok|.ok,*) m4_ifvaln($3,$3) ;;
+ .|.no|.no,*) m4_default($4,[m4_ifval($2,[AC_APPEND_FLAG([$2], [$1])])])
;;
+ *) m4_default($3,[AC_APPEND_FLAG([$VAR], [$1])]) ;;
+esac
+AS_VAR_POPDEF([VAR])dnl
+])dnl AC_FLAGS_WARN_ALL
+dnl implementation tactics:
+dnl the for-argument contains a list of options. The first part of
+dnl these does only exist to detect the compiler - usually it is
+dnl a global option to enable -ansi or -extrawarnings. All other
+dnl compilers will fail about it. That was needed since a lot of
+dnl compilers will give false positives for some option-syntax
+dnl like -Woption or -Xoption as they think of it is a pass-through
+dnl to later compile stages or something. The "%" is used as a
+dnl delimiter. A non-option comment can be given after "%%" marks
+dnl which will be shown but not added to the respective C/CXXFLAGS.
+
+AC_DEFUN([AC_CFLAGS_WARN_ALL],[dnl
+AC_LANG_PUSH([C])
+AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
+AC_LANG_POP([C])
+])
+
+AC_DEFUN([AC_CXXFLAGS_WARN_ALL],[dnl
+AC_LANG_PUSH([C++])
+AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
+AC_LANG_POP([C++])
+])
+
+AC_DEFUN([AC_FCFLAGS_WARN_ALL],[dnl
+AC_LANG_PUSH([Fortran])
+AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
+AC_LANG_POP([Fortran])
+])
On Fri, Jan 10, 2014 at 10:30 AM, Dale Visser <[email protected]> wrote:
> The inspiration for this comes from an earlier discussion on the
> 'autoconf' list:
> http://lists.gnu.org/archive/html/autoconf/2013-10/msg00025.html
>
> The basic idea is to overall enhance the security of code built using
> autoconf, by turning on compiler warnings that the developers wouldn't
> otherwise think to.
>
> The patch ports over AX_FLAGS_WARN_ALL from the autoconf archive, and
> invokes it by default within AC_PROG_CC, AC_PROG_CXX and AC_PROG_FC. Of
> course, a mechanism is provided for turning off the new behavior, i.e.,
> restoring the classic "no extra warnings" mode.
>
> ---
> lib/autoconf/lang.m4 | 136
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 136 insertions(+)
>
> diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
> index c99f152..8d2ba73 100644
> --- a/lib/autoconf/lang.m4
> +++ b/lib/autoconf/lang.m4
> @@ -719,3 +719,139 @@ ac_objext=$OBJEXT
> AC_DEFUN([AC_LANG_WERROR],
> [m4_divert_text([DEFAULTS], [ac_[]_AC_LANG_ABBREV[]_werror_flag=])
> ac_[]_AC_LANG_ABBREV[]_werror_flag=yes])# AC_LANG_WERROR
> +
> +#
> +# SYNOPSIS
> +#
> +# AC_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
> +#
> +# DESCRIPTION
> +#
> +# FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
> +# added in between.
> +#
> +# If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
> +# CFLAGS) is used. FLAGS-VARIABLE is not changed if it already contains
> +# FLAG. If FLAGS-VARIABLE is unset in the shell, it is set to exactly
> +# FLAG.
> +#
> +# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
> +# NOTE: Copied from AX_APPEND_FLAG in autoconf-archive, which had
> copyright
> +# assigned as follows:
> +#
> +# Copyright (c) 2008 Guido U. Draheim <[email protected]>
> +# Copyright (c) 2011 Maarten Bosmans <[email protected]>
> +#
> +
> +#serial 2
> +
> +AC_DEFUN([AC_APPEND_FLAG],
> +[AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])dnl
> +AS_VAR_SET_IF(FLAGS,
> + [case " AS_VAR_GET(FLAGS) " in
> + *" $1 "*)
> + AC_RUN_LOG([: FLAGS already contains $1])
> + ;;
> + *)
> + AC_RUN_LOG([: FLAGS="$FLAGS $1"])
> + AS_VAR_SET(FLAGS, ["AS_VAR_GET(FLAGS) $1"])
> + ;;
> + esac],
> + [AS_VAR_SET(FLAGS,["$1"])])
> +AS_VAR_POPDEF([FLAGS])dnl
> +])dnl AC_APPEND_FLAG
> +
> +#
> +# SYNOPSIS
> +#
> +# AC_CFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
> +# AC_CXXFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
> +# AC_FCFLAGS_WARN_ALL [(shellvar [,default, [A/NA]])]
> +#
> +# DESCRIPTION
> +#
> +# Try to find a compiler option that enables most reasonable warnings.
> +#
> +# For the GNU compiler it will be -Wall (and -ansi -pedantic) The result
> +# is added to the shellvar being CFLAGS, CXXFLAGS, or FCFLAGS by
> default.
> +#
> +# Currently this macro knows about the GCC, Solaris, Digital Unix, AIX,
> +# HP-UX, IRIX, NEC SX-5 (Super-UX 10), Cray J90 (Unicos 10.0.0.8), and
> +# Intel compilers. For a given compiler, the Fortran flags are much
> more
> +# experimental than their C equivalents.
> +#
> +# - $1 shell-variable-to-add-to : CFLAGS, CXXFLAGS, or FCFLAGS
> +# - $2 add-value-if-not-found : nothing
> +# - $3 action-if-found : add value to shellvariable
> +# - $4 action-if-not-found : nothing
> +#
> +# NOTE: These macros depend on AX_APPEND_FLAG.
> +# NOTE: Based upon AX_*FLAGS_WARN_ALL from autoconf-archive, which had
> +# copyright assigned as follows:
> +#
> +# Copyright (c) 2008 Guido U. Draheim <[email protected]>
> +# Copyright (c) 2010 Rhys Ulerich <[email protected]>
> +#
> +
> +#serial 14
> +
> +AC_DEFUN([AC_FLAGS_WARN_ALL],[dnl
> +AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl
> +AS_VAR_PUSHDEF([VAR],[ac_cv_[]_AC_LANG_ABBREV[]flags_warn_all])dnl
> +AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for maximum warnings],
> +VAR,[VAR="no, unknown"
> +ac_save_[]FLAGS="$[]FLAGS"
> +for ac_arg dnl
> +in "-warn all % -warn all" dnl Intel
> + "-pedantic % -Wall" dnl GCC
> + "-xstrconst % -v" dnl Solaris C
> + "-std1 % -verbose -w0 -warnprotos" dnl Digital Unix
> + "-qlanglvl=ansi % -qsrcmsg -qinfo=all:noppt:noppc:noobs:nocnd" dnl AIX
> + "-ansi -ansiE % -fullwarn" dnl IRIX
> + "+ESlit % +w1" dnl HP-UX C
> + "-Xc % -pvctl[,]fullmsg" dnl NEC SX-5 (Super-UX 10)
> + "-h conform % -h msglevel 2" dnl Cray C (Unicos)
> + #
> +do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
> + AC_COMPILE_IFELSE([AC_LANG_PROGRAM],
> + [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
> +done
> +FLAGS="$ac_save_[]FLAGS"
> +])
> +AS_VAR_POPDEF([FLAGS])dnl
> +AC_REQUIRE([AC_APPEND_FLAG])
> +case ".$VAR" in
> + .ok|.ok,*) m4_ifvaln($3,$3) ;;
> + .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2],
> [$1])])]) ;;
> + *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
> +esac
> +AS_VAR_POPDEF([VAR])dnl
> +])dnl AC_FLAGS_WARN_ALL
> +dnl implementation tactics:
> +dnl the for-argument contains a list of options. The first part of
> +dnl these does only exist to detect the compiler - usually it is
> +dnl a global option to enable -ansi or -extrawarnings. All other
> +dnl compilers will fail about it. That was needed since a lot of
> +dnl compilers will give false positives for some option-syntax
> +dnl like -Woption or -Xoption as they think of it is a pass-through
> +dnl to later compile stages or something. The "%" is used as a
> +dnl delimiter. A non-option comment can be given after "%%" marks
> +dnl which will be shown but not added to the respective C/CXXFLAGS.
> +
> +AC_DEFUN([AC_CFLAGS_WARN_ALL],[dnl
> +AC_LANG_PUSH([C])
> +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
> +AC_LANG_POP([C])
> +])
> +
> +AC_DEFUN([AC_CXXFLAGS_WARN_ALL],[dnl
> +AC_LANG_PUSH([C++])
> +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
> +AC_LANG_POP([C++])
> +])
> +
> +AC_DEFUN([AC_FCFLAGS_WARN_ALL],[dnl
> +AC_LANG_PUSH([Fortran])
> +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4])
> +AC_LANG_POP([Fortran])
> +])
> --
> 1.8.3.2
>
>
> From d03cbf1f4260494590c0c597d76339bfa1ab462d Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Fri, 20 Dec 2013 13:10:33 -0500
> Subject: [PATCH 02/10] Missed renaming AX_APPEND_FLAG in two locations.
>
> ---
> lib/autoconf/lang.m4 | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
> index 8d2ba73..e17d70f 100644
> --- a/lib/autoconf/lang.m4
> +++ b/lib/autoconf/lang.m4
> @@ -822,8 +822,8 @@ AS_VAR_POPDEF([FLAGS])dnl
> AC_REQUIRE([AC_APPEND_FLAG])
> case ".$VAR" in
> .ok|.ok,*) m4_ifvaln($3,$3) ;;
> - .|.no|.no,*) m4_default($4,[m4_ifval($2,[AX_APPEND_FLAG([$2],
> [$1])])]) ;;
> - *) m4_default($3,[AX_APPEND_FLAG([$VAR], [$1])]) ;;
> + .|.no|.no,*) m4_default($4,[m4_ifval($2,[AC_APPEND_FLAG([$2],
> [$1])])]) ;;
> + *) m4_default($3,[AC_APPEND_FLAG([$VAR], [$1])]) ;;
> esac
> AS_VAR_POPDEF([VAR])dnl
> ])dnl AC_FLAGS_WARN_ALL
> --
> 1.8.3.2
>
>
> From 9a1432215b7ae18b8913e000c77fd5d4618c6b8e Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Fri, 20 Dec 2013 16:29:59 -0500
> Subject: [PATCH 03/10] Added first attempt at useful documentation for
> FLAGS_WARN_ALL.
>
> ---
> doc/autoconf.texi | 65
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 65 insertions(+)
>
> diff --git a/doc/autoconf.texi b/doc/autoconf.texi
> index a2368e7..b68d19d 100644
> --- a/doc/autoconf.texi
> +++ b/doc/autoconf.texi
> @@ -23427,6 +23427,71 @@ The current language does not change.
> @code{AC_LANG_PUSH} is preferred
> (@pxref{AC_LANG_PUSH}).
> @end defmac
>
> +@anchor{AC_CFLAGS_WARN_ALL}
> +@defmac AC_CFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
> @var{add-value-if-not-found}, @var{action-if-found},
> @var{action-if-not-found})
> +@acindex{CFLAGS_WARN_ALL}
> +Try to find a C compiler option that enables most reasonable warnings. See
> +@pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters. The
> most
> +typical usage is shown below.
> +
> +@example
> +AC_CFLAGS_WARN_ALL
> +@end example
> +@end defmac
> +
> +@anchor{AC_CXXFLAGS_WARN_ALL}
> +@defmac AC_CXXFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
> @var{add-value-if-not-found}, @var{action-if-found},
> @var{action-if-not-found})
> +@acindex{CXXFLAGS_WARN_ALL}
> +Try to find a C++ compiler option that enables most reasonable warnings.
> See
> +@pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters. The
> most
> +typical usage is shown below.
> +
> +@example
> +AC_CXXFLAGS_WARN_ALL
> +@end example
> +@end defmac
> +
> +@anchor{AC_FCFLAGS_WARN_ALL}
> +@defmac AC_FCFLAGS_WARN_ALL(@var{shell-variable-to-add-to},
> @var{add-value-if-not-found}, @var{action-if-found},
> @var{action-if-not-found})
> +@acindex{FCFLAGS_WARN_ALL}
> +Try to find a Fortran compiler option that enables most reasonable
> warnings.
> +See @pxref{AC_FLAGS_WARN_ALL} for how to use the (optional) parameters.
> The most
> +typical usage is shown below.
> +
> +@example
> +AC_FCFLAGS_WARN_ALL
> +@end example
> +@end defmac
> +
> +@anchor{AC_FLAGS_WARN_ALL}
> +@defmac AC_FLAGS_WARN_ALL(@var{shell-variable-to-add-to},
> @var{add-value-if-not-found}, @var{action-if-found},
> @var{action-if-not-found})
> +@acindex{FLAGS_WARN_ALL}
> +Try to find a compiler option that enables most reasonable warnings.
> +
> +Usually not used directly. Instead, use @pxref{AC_CFLAGS_WARN_ALL},
> +@pxref{AC_CXXFLAGS_WARN_ALL}, or @pxref{AC_FCFLAGS_WARN_ALL}, all of
> which perform
> +a requisite @pxref{AC_LANG_PUSH}, and then invoke this macro without
> altering any
> +positional parameters they were provided.
> +
> +The first positional parameter defines the shell variable to use, and
> +if not provided, depends on @pxref{AC_LANG_PUSH} having been invoked
> properly.
> +If appropriate warning flag values can be automatically determined for the
> +compiler, then the third positional parameter (if present) defines an
> +alternate action to take instead of appending to the shell variable. If no
> +appropriate warning flag values could be determined, then the second
> +positional parameter (if present) defines alternate flags to append to the
> +shell variable, unless the fourth positional parameter is present, in
> which
> +case it defines an alternate action to take instead of appending to the
> shell
> +variable.
> +@end defmac
> +
> +@defmac AC_APPEND_FLAG(@var{add-value})
> +@acindex{APPEND_FLAG}
> +Used internally by @pxref{AC_FLAGS_WARN_ALL}. Behavior is to append the
> given to
> +the shell variable determined or provided in the call to
> +@pxref{AC_FLAGS_WARN_ALL}, but only if it is not already present there.
> +@end defmac
> +
> @defmac AC_LINK_FILES (@var{source}@dots{}, @var{dest}@dots{})
> @acindex{LINK_FILES}
> This is an obsolete version of @code{AC_CONFIG_LINKS}
> --
> 1.8.3.2
>
>
> From 403e3d73c47231304124fc3bdaa619ed2f745695 Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Wed, 8 Jan 2014 11:07:31 -0500
> Subject: [PATCH 04/10] Figured out how to include AC_FLAGS_WARN_ALL in
> AC_PROG_CC w/o recursive expansion drama.
>
> ---
> lib/autoconf/c.m4 | 1 +
> lib/autoconf/lang.m4 | 2 +-
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
> index 25780f9..b01c1f1 100644
> --- a/lib/autoconf/c.m4
> +++ b/lib/autoconf/c.m4
> @@ -491,6 +491,7 @@ _AC_PROG_CC_C11([ac_prog_cc_stdc=c11
> [ac_prog_cc_stdc=no
> ac_cv_prog_cc_stdc=no])])])
> dnl
> +AC_FLAGS_WARN_ALL
> AC_LANG_POP(C)dnl
> ])# AC_PROG_CC
>
> diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
> index e17d70f..0c86b63 100644
> --- a/lib/autoconf/lang.m4
> +++ b/lib/autoconf/lang.m4
> @@ -813,7 +813,7 @@ in "-warn all % -warn all" dnl Intel
> "-h conform % -h msglevel 2" dnl Cray C (Unicos)
> #
> do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'`
> - AC_COMPILE_IFELSE([AC_LANG_PROGRAM],
> + _AC_COMPILE_IFELSE([AC_LANG_PROGRAM],
> [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break])
> done
> FLAGS="$ac_save_[]FLAGS"
> --
> 1.8.3.2
>
>
> From f02f187b1b118854ed0d66e5d421cb9287e5b391 Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Wed, 8 Jan 2014 14:58:50 -0500
> Subject: [PATCH 05/10] Pass any extra arguments to AC_FLAGS_WARN_ALL, e.g.,
> useful for turning off the warning flags.
>
> ---
> lib/autoconf/c.m4 | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
> index b01c1f1..bb2e414 100644
> --- a/lib/autoconf/c.m4
> +++ b/lib/autoconf/c.m4
> @@ -491,7 +491,7 @@ _AC_PROG_CC_C11([ac_prog_cc_stdc=c11
> [ac_prog_cc_stdc=no
> ac_cv_prog_cc_stdc=no])])])
> dnl
> -AC_FLAGS_WARN_ALL
> +AC_FLAGS_WARN_ALL(m4_shift($@))
> AC_LANG_POP(C)dnl
> ])# AC_PROG_CC
>
> --
> 1.8.3.2
>
>
> From 705ca5d539f1bbbfad7d681c972d6b059da84c23 Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Wed, 8 Jan 2014 15:52:40 -0500
> Subject: [PATCH 06/10] Enabled warnings by default in AC_PROG_CXX.
>
> ---
> lib/autoconf/c.m4 | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
> index bb2e414..2c18463 100644
> --- a/lib/autoconf/c.m4
> +++ b/lib/autoconf/c.m4
> @@ -733,6 +733,7 @@ _AC_PROG_CXX_CXX11([ac_prog_cxx_stdcxx=cxx11
> ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98],
> [ac_prog_cxx_stdcxx=no
> ac_cv_prog_cxx_stdcxx=no])])
> +AC_FLAGS_WARN_ALL(m4_shift($@))
> AC_LANG_POP(C++)dnl
> ])# AC_PROG_CXX
>
> --
> 1.8.3.2
>
>
> From 4c9afb42c78fc149a1af498b71d3842f20df65c3 Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Wed, 8 Jan 2014 16:14:54 -0500
> Subject: [PATCH 07/10] Added warnings by default to AC_PROG_FC. Still need
> to
> test with warning-generating code, but so far verified warnings flag is
> actually added.
>
> ---
> lib/autoconf/fortran.m4 | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
> index f20b029..0dac562 100644
> --- a/lib/autoconf/fortran.m4
> +++ b/lib/autoconf/fortran.m4
> @@ -387,6 +387,7 @@ if test $ac_compiler_gnu = yes; then
> else
> GFC=
> fi
> +AC_FLAGS_WARN_ALL(m4_shift($@))
> AC_LANG_POP(Fortran)dnl
> ])# AC_PROG_FC
>
> --
> 1.8.3.2
>
>
> From 4f338859104cc5faa8755b448ecb629d9c0bae90 Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Thu, 9 Jan 2014 09:33:23 -0500
> Subject: [PATCH 08/10] Needed to do m4_shift2 for AC_PROG_FC case.
>
> ---
> lib/autoconf/fortran.m4 | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
> index 0dac562..94ec01f 100644
> --- a/lib/autoconf/fortran.m4
> +++ b/lib/autoconf/fortran.m4
> @@ -387,7 +387,7 @@ if test $ac_compiler_gnu = yes; then
> else
> GFC=
> fi
> -AC_FLAGS_WARN_ALL(m4_shift($@))
> +AC_FLAGS_WARN_ALL(m4_shift2($@))
> AC_LANG_POP(Fortran)dnl
> ])# AC_PROG_FC
>
> --
> 1.8.3.2
>
>
> From 0588622ada92c5b776829a507386d7355241361f Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Thu, 9 Jan 2014 09:48:41 -0500
> Subject: [PATCH 09/10] Documented parameter changes in AC_PROG_CC,
> AC_PROG_CXX
> and AC_PROG_FC.
>
> ---
> lib/autoconf/c.m4 | 16 ++++++++++++++--
> lib/autoconf/fortran.m4 | 8 +++++++-
> 2 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
> index 2c18463..c018c92 100644
> --- a/lib/autoconf/c.m4
> +++ b/lib/autoconf/c.m4
> @@ -424,11 +424,17 @@ AU_DEFUN([ac_cv_prog_gcc],
> [ac_cv_c_compiler_gnu])
>
>
> -# AC_PROG_CC([COMPILER ...])
> +# AC_PROG_CC([COMPILER ...], ...)
> # --------------------------
> # COMPILER ... is a space separated list of C compilers to search for.
> # This just gives the user an opportunity to specify an alternative
> # search list for the C compiler.
> +# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
> +# are no extra parameters, then compiler warnings will be turned on. An
> +# example of how to avoid this is invoking
> +# AC_PROG_CC([COMPILER ...], [], [], [echo No extra warnings please.])
> +# Where the final parameter is providing an alternate action to enabling
> +# warning flags.
> AN_MAKEVAR([CC], [AC_PROG_CC])
> AN_PROGRAM([cc], [AC_PROG_CC])
> AN_PROGRAM([gcc], [AC_PROG_CC])
> @@ -675,7 +681,7 @@ AU_DEFUN([ac_cv_prog_gxx],
> [ac_cv_cxx_compiler_gnu])
>
>
> -# AC_PROG_CXX([LIST-OF-COMPILERS])
> +# AC_PROG_CXX([LIST-OF-COMPILERS], ...)
> # --------------------------------
> # LIST-OF-COMPILERS is a space separated list of C++ compilers to search
> # for (if not specified, a default list is used). This just gives the
> @@ -687,6 +693,12 @@ AU_DEFUN([ac_cv_prog_gxx],
> # RCC Rational C++
> # xlC_r AIX C Set++ (with support for reentrant code)
> # xlC AIX C Set++
> +# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
> +# are no extra parameters, then compiler warnings will be turned on. An
> +# example of how to avoid this is invoking
> +# AC_PROG_CXX([LIST-OF-COMPILERS], [], [], [echo No extra warnings
> please.])
> +# Where the final parameter is providing an alternate action to enabling
> +# warning flags.
> AN_MAKEVAR([CXX], [AC_PROG_CXX])
> AN_PROGRAM([CC], [AC_PROG_CXX])
> AN_PROGRAM([c++], [AC_PROG_CXX])
> diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4
> index 94ec01f..8280e48 100644
> --- a/lib/autoconf/fortran.m4
> +++ b/lib/autoconf/fortran.m4
> @@ -371,10 +371,16 @@ AC_LANG_POP(Fortran 77)dnl
> ])# AC_PROG_F77
>
>
> -# AC_PROG_FC([COMPILERS...], [DIALECT])
> +# AC_PROG_FC([COMPILERS...], [DIALECT], ...)
> # -------------------------------------
> # COMPILERS is a space separated list of Fortran 77 compilers to search
> # for, and [DIALECT] is an optional dialect. See also _AC_PROG_FC.
> +# Any extra parameters will be passed on to AC_FLAGS_WARN_ALL. If there
> +# are no extra parameters, then compiler warnings will be turned on. An
> +# example of how to avoid this is invoking
> +# AC_PROG_FC([COMPILERS...], [DIALECT], [], [], [echo No extra warnings
> please.])
> +# Where the final parameter is providing an alternate action to enabling
> +# warning flags.
> AC_DEFUN([AC_PROG_FC],
> [AC_LANG_PUSH(Fortran)dnl
> AC_ARG_VAR([FC], [Fortran compiler command])dnl
> --
> 1.8.3.2
>
>
> From 7dc715abed03c77d59a28cd1ddaaa377356080fb Mon Sep 17 00:00:00 2001
> From: Dale Visser <[email protected]>
> Date: Thu, 9 Jan 2014 10:17:12 -0500
> Subject: [PATCH 10/10] Added to documentation about new default behaviour,
> and
> how one restores the old behaviour.
>
> ---
> doc/autoconf.texi | 36 +++++++++++++++++++++++++++++++++---
> 1 file changed, 33 insertions(+), 3 deletions(-)
>
> diff --git a/doc/autoconf.texi b/doc/autoconf.texi
> index b68d19d..87c70fb 100644
> --- a/doc/autoconf.texi
> +++ b/doc/autoconf.texi
> @@ -7160,7 +7160,7 @@ makes this invalid. That is why Autoconf stopped
> issuing
> @end table
>
> @anchor{AC_PROG_CC}
> -@defmac AC_PROG_CC (@ovar{compiler-search-list})
> +@defmac AC_PROG_CC (@ovar{compiler-search-list}, @dots{})
> @acindex{PROG_CC}
> @evindex CC
> @evindex CFLAGS
> @@ -7213,6 +7213,15 @@ other compilers. If your package does not like
> this default, then it is
> acceptable to insert the line @samp{: $@{CFLAGS=""@}} after @code{AC_INIT}
> and before @code{AC_PROG_CC} to select an empty default instead.
>
> +Scan for common flags that enable compiler warnings. If found, append them
> +to @code{CFLAGS}. To modify this behaviour, for example, to restore the
> old
> +no-warning-flag behaviour, add parameters which will get shifted by 1,
> +and passed on to @code{AC_FLAGS_WARN_ALL}.
> +
> +@example
> +AC_PROG_CC([], [], [], [echo No warning flags please.])
> +@end example
> +
> Many Autoconf macros use a compiler, and thus call
> @samp{AC_REQUIRE([AC_PROG_CC])} to ensure that the compiler has been
> determined before the body of the outermost @code{AC_DEFUN} macro.
> @@ -7537,7 +7546,7 @@ compiler fix the header files automatically when
> installed.
> @subsection C++ Compiler Characteristics
>
>
> -@defmac AC_PROG_CXX (@ovar{compiler-search-list})
> +@defmac AC_PROG_CXX (@ovar{compiler-search-list}, @dots{})
> @acindex{PROG_CXX}
> @evindex CXX
> @evindex CXXFLAGS
> @@ -7599,6 +7608,16 @@ systems where G++ does not accept @option{-g}), or
> @option{-g} for other
> compilers. If your package does not like this default, then it is
> acceptable to insert the line @samp{: $@{CXXFLAGS=""@}} after
> @code{AC_INIT}
> and before @code{AC_PROG_CXX} to select an empty default instead.
> +
> +Scan for common flags that enable compiler warnings. If found, append them
> +to @code{CXXFLAGS}. To modify this behaviour, for example, to restore the
> old
> +no-warning-flag behaviour, add parameters which will get shifted by 1,
> +and passed on to @code{AC_FLAGS_WARN_ALL}.
> +
> +@example
> +AC_PROG_CXX([], [], [], [echo No warning flags please.])
> +@end example
> +
> @end defmac
>
> @defmac AC_PROG_CXXCPP
> @@ -7825,7 +7844,7 @@ The result of the GNU test is cached in the
> @code{ac_cv_prog_f77_g} variable.
> @end defmac
>
> -@defmac AC_PROG_FC (@ovar{compiler-search-list}, @ovar{dialect})
> +@defmac AC_PROG_FC (@ovar{compiler-search-list}, @ovar{dialect}, @dots{})
> @acindex{PROG_FC}
> @evindex FC
> @evindex FCFLAGS
> @@ -7863,6 +7882,17 @@ set @code{FCFLAGS} to @option{-g} for all other
> Fortran compilers.
> The result of the GNU test is cached in the @code{ac_cv_fc_compiler_gnu}
> variable, acceptance of @option{-g} in the @code{ac_cv_prog_fc_g}
> variable.
> +
> +Scan for common flags that enable compiler warnings. If found, append them
> +to @code{FCFLAGS}. To modify this behaviour, for example, to restore the
> old
> +no-warning-flag behaviour, add parameters which will get shifted by 2,
> +and passed on to @code{AC_FLAGS_WARN_ALL}.
> +
> +@example
> +AC_PROG_FC([], [], [], [], [echo No warning flags please.])
> +@end example
> +
> +
> @end defmac
>
> @defmac AC_PROG_F77_C_O
> --
> 1.8.3.2
>
>
>
>
--
The plural of 'anecdote' is not 'data'.