I have an updated patch (see below) inspired by "goto fail", in particular, a recent essay by David Wheeler (see http://www.dwheeler.com/essays/apple-goto-fail.html). The clang compiler would have caught the "goto fail" issue if it had been used to analyze the code with the -Wunreachable-code option enabled. This patch is only slightly modified from my previous version in that it will add -Wunreachable-code in addition to -Wall for both clang and gcc.
Unfortunately, on gcc, this is now a no-op. But even those who build with gcc may use clang for analysis. At some future point, gcc may stop silently ignoring -Wunreachable-code (see https://gcc.gnu.org/ml/gcc-help/2011-05/msg00360.html), and I have covered for that, too. When and if that happens, only -Wall will be used for gcc. Best regards, Dale diff --git a/doc/autoconf.texi b/doc/autoconf.texi index ace1675..68db110 100644 --- a/doc/autoconf.texi +++ b/doc/autoconf.texi @@ -7214,6 +7214,15 @@ other compilers. If your package does not like this default, then it is acceptable to insert the line @samp{: $@{CFLAGS=""@}} after @code{AC_INIT} and before @code{AC_PROG_CC} to select an empty default instead. +Scan for common flags that enable compiler warnings. If found, append them +to @code{CFLAGS}. To modify this behaviour, for example, to restore the old +no-warning-flag behaviour, add the following line before you invoke +@code{AC_PROG_CC}: + +@example +enable_default_warning_flags=$@{enable_default_warning_flags:-no@} +@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. @@ -7604,6 +7613,16 @@ 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{: $@{CXXFLAGS=""@}} after @code{AC_INIT} and before @code{AC_PROG_CXX} to select an empty default instead. + +Scan for common flags that enable compiler warnings. If found, append them +to @code{CXXFLAGS}. To modify this behaviour, for example, to restore the old +no-warning-flag behaviour, add the following line before you invoke +@code{AC_PROG_CXX}: + +@example +enable_default_warning_flags=$@{enable_default_warning_flags:-no@} +@end example + @end defmac @defmac AC_PROG_CXXCPP @@ -7868,6 +7887,17 @@ environment, then set it to @option{-g -02} for a GNU Fortran compiler (or 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 the following line before you invoke +@code{AC_PROG_FC}: + +@example +enable_default_warning_flags=$@{enable_default_warning_flags:-no@} +@end example + + @end defmac @defmac AC_PROG_F77_C_O @@ -23472,6 +23502,158 @@ 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. To use with another +language, such as Objective C, it is necessary to first push the language +first. + +@example +AC_LANG_PUSH([Objective C]) +AC_FLAGS_WARN_ALL +AC_LANG_POP +@end example + +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. + +@code{AC_FLAGS_WARN_ALL} is invoked by @code{AC_PROG_CC}, @code{AC_PROG_CXX}, +and @code{AC_PROG_FC} by default. The addition of the detected default +warning flags is controlled by the "default_warning_flags" feature, which is +enabled by default. It may be disabled with an option passed to the generated +configure script. To suppress the actual addition of any default warning +flags in the configure.ac file, i.e., to restore the behavior from previous +versions of autoconf, add the following line before you invoke +@code{AC_FLAGS_WARN_ALL}, whether explicitly or implicitly: + +@example +enable_default_warning_flags=@{enable_default_warning_flags:-no@} +@end example +@end defmac + +@anchor{AC_APPEND_FLAG} +@defmac AC_APPEND_FLAG (@var{add-value}) +@acindex{APPEND_FLAG} +Append the given flag to the FLAGS variable previously determined, but only if +the given flag is not already present. Used internally by +@pxref{AC_FLAGS_WARN_ALL}. Typically, it is desirable to use +@pxref{AC_APPEND_FLAG_IFVALID} instead, since that performs additional a check +on the given flag. +@end defmac + +@anchor{AC_APPEND_CFLAG_IFVALID} +@defmac AC_APPEND_CFLAG_IFVALID (@var{add-value}) +@acindex{APPEND_CFLAG_IFVALID} +Sets the current language to C, then invokes @pxref{AC_APPEND_FLAG_IFVALID}. +The following example shows a typical usage, adding @option{-Wfancy-warnings} +on top of whatever warning flags are already added for the current C +compiler, but only if @option{-Wfancy-warnings} is a valid flag. + +@example +AC_PROG_CC +AC_APPEND_CFLAG_IFVALID([-Wfancy-warnings]) +@end example + +@end defmac + +@anchor{AC_APPEND_CXXFLAG_IFVALID} +@defmac AC_APPEND_CXXFLAG_IFVALID (@var{add-value}) +@acindex{APPEND_CXXFLAG_IFVALID} +Sets the current language to C++, then invokes @pxref{AC_APPEND_FLAG_IFVALID}. +The following example shows a typical usage, adding @option{-Wfancy-warnings} +on top of whatever warning flags are already added for the current C++ +compiler, but only if @option{-Wfancy-warnings} is a valid flag. + +@example +AC_PROG_CXX +AC_APPEND_CXXFLAG_IFVALID([-Wfancy-warnings]) +@end example + +@end defmac + +@anchor{AC_APPEND_FCFLAG_IFVALID} +@defmac AC_APPEND_FCFLAG_IFVALID (@var{add-value}) +@acindex{APPEND_FCFLAG_IFVALID} +Sets the current language to Fortran, then invokes +@pxref{AC_APPEND_FLAG_IFVALID}. +The following example shows a typical usage, adding @option{-Wfancy-warnings} +on top of whatever warning flags are already added for the current Fortran +compiler, but only if @option{-Wfancy-warnings} is a valid flag. + +@example +AC_PROG_FC +AC_APPEND_FCFLAG_IFVALID([-Wfancy-warnings]) +@end example +@end defmac + +@anchor{AC_APPEND_FLAG_IFVALID} +@defmac AC_APPEND_FLAG_IFVALID (@var{add-value}) +@acindex{APPEND_FLAG_IFVALID} +Determine the appropriate compiler flags variable for the current language, +compile a test program using the given flag(s), and if the compile process +exits normally, append it to the flags variable using @pxref{AC_APPEND_FLAG}. +Used internally by @pxref{AC_APPEND_CFLAG_IFVALID}, +@pxref{AC_APPEND_CXXFLAG_IFVALID}, and @pxref{AC_APPEND_FCFLAG_IFVALID}. To +use with another language, such as Objective C, it is necessary to first push +the language first. + +@example +AC_LANG_PUSH([Objective C]) +AC_APPEND_FLAG_IFVALID([-Wno-comment]) +AC_LANG_POP +@end example +@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 9b7aa6b..2537ed9 100644 --- a/lib/autoconf/c.m4 +++ b/lib/autoconf/c.m4 @@ -429,6 +429,9 @@ AU_DEFUN([ac_cv_prog_gcc], # 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. +# To avoid the automatic addition of some default compiler warning flags, +# add the following line before you invoke AC_PROG_CC: +# enable_default_warning_flags=${enable_default_warning_flags:-no} AN_MAKEVAR([CC], [AC_PROG_CC]) AN_PROGRAM([cc], [AC_PROG_CC]) AN_PROGRAM([gcc], [AC_PROG_CC]) @@ -491,6 +494,7 @@ _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 @@ -686,6 +690,9 @@ AU_DEFUN([ac_cv_prog_gxx], # RCC Rational C++ # xlC_r AIX C Set++ (with support for reentrant code) # xlC AIX C Set++ +# To avoid the automatic addition of some default compiler warning flags, +# add the following line before you invoke AC_PROG_CXX: +# enable_default_warning_flags=${enable_default_warning_flags:-no} AN_MAKEVAR([CXX], [AC_PROG_CXX]) AN_PROGRAM([CC], [AC_PROG_CXX]) AN_PROGRAM([c++], [AC_PROG_CXX]) @@ -732,6 +739,7 @@ _AC_PROG_CXX_CXX11([ac_prog_cxx_stdcxx=cxx11 ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98], [ac_prog_cxx_stdcxx=no ac_cv_prog_cxx_stdcxx=no])]) +AC_FLAGS_WARN_ALL AC_LANG_POP(C++)dnl ])# AC_PROG_CXX diff --git a/lib/autoconf/fortran.m4 b/lib/autoconf/fortran.m4 index e0f66f1..ffe7aba 100644 --- a/lib/autoconf/fortran.m4 +++ b/lib/autoconf/fortran.m4 @@ -375,6 +375,9 @@ AC_LANG_POP(Fortran 77)dnl # ------------------------------------- # COMPILERS is a space separated list of Fortran 77 compilers to search # for, and [DIALECT] is an optional dialect. See also _AC_PROG_FC. +# To avoid the automatic addition of some default compiler warning flags, +# add the following line before you invoke AC_PROG_FC: +# enable_default_warning_flags=${enable_default_warning_flags:-no} AC_DEFUN([AC_PROG_FC], [AC_LANG_PUSH(Fortran)dnl AC_ARG_VAR([FC], [Fortran compiler command])dnl @@ -387,6 +390,7 @@ if test $ac_compiler_gnu = yes; then else GFC= fi +AC_FLAGS_WARN_ALL AC_LANG_POP(Fortran)dnl ])# AC_PROG_FC diff --git a/lib/autoconf/general.m4 b/lib/autoconf/general.m4 index 59d204f..aff8540 100644 --- a/lib/autoconf/general.m4 +++ b/lib/autoconf/general.m4 @@ -433,6 +433,7 @@ m4_wrap_lifo([m4_divert_text([DEFAULTS], ac_subst_files='m4_ifdef([_AC_SUBST_FILES], [m4_defn([_AC_SUBST_FILES])])' ac_user_opts=' enable_option_checking +enable_default_warning_flags m4_ifdef([_AC_USER_OPTS], [m4_defn([_AC_USER_OPTS]) ])' m4_ifdef([_AC_PRECIOUS_VARS], @@ -1447,6 +1448,9 @@ AC_DEFUN([AC_PRESERVE_HELP_ORDER], [m4_divert_once([HELP_ENABLE], [[ Optional Features and Packages: --disable-option-checking ignore unrecognized --enable/--with options + --disable-default-warning-flags + suppresses the addition of automatically determined + default compiler warning flags --disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no) --enable-FEATURE[=ARG] include FEATURE [ARG=yes] --with-PACKAGE[=ARG] use PACKAGE [ARG=yes] @@ -1478,6 +1482,9 @@ AC_DEFUN([AC_ARG_ENABLE], [m4_divert_once([HELP_ENABLE], [[ Optional Features: --disable-option-checking ignore unrecognized --enable/--with options + --disable-default-warning-flags + suppresses the addition of automatically determined + default compiler warning flags --disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no) --enable-FEATURE[=ARG] include FEATURE [ARG=yes]]])])dnl m4_divert_once([HELP_ENABLE], [$2])dnl @@ -2633,9 +2640,11 @@ m4_define([_AC_COMPILE_IFELSE_BODY], ])# _AC_COMPILE_IFELSE_BODY -# _AC_COMPILE_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE]) +# _AC_COMPILE_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE], [ERRFILE]) # ---------------------------------------------------------------- # Try to compile PROGRAM. +# If ERRFILE is provided, any contents of the stderr will be placed +# in ERRFILE, which should be deleted by the caller. # This macro can be used during the selection of a compiler. AC_DEFUN([_AC_COMPILE_IFELSE], [AC_REQUIRE_SHELL_FN([ac_fn_]_AC_LANG_ABBREV[_try_compile], @@ -2644,10 +2653,10 @@ AC_DEFUN([_AC_COMPILE_IFELSE], [$0_BODY])]dnl [m4_ifvaln([$1], [AC_LANG_CONFTEST([$1])])]dnl [AS_IF([ac_fn_[]_AC_LANG_ABBREV[]_try_compile "$LINENO"], [$2], [$3]) +m4_ifvaln([$4], [cp conftest.err "$4"]) rm -f core conftest.err conftest.$ac_objext[]m4_ifval([$1], [ conftest.$ac_ext])[]dnl ])# _AC_COMPILE_IFELSE - # AC_COMPILE_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE]) # --------------------------------------------------------------- # Try to compile PROGRAM. Requires that the compiler for the current @@ -2697,11 +2706,14 @@ m4_define([_AC_LINK_IFELSE_BODY], ])# _AC_LINK_IFELSE_BODY -# _AC_LINK_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE]) +# _AC_LINK_IFELSE(PROGRAM, [ACTION-IF-TRUE], [ACTION-IF-FALSE], [ERRFILE]) # ------------------------------------------------------------- # Try to link PROGRAM. # This macro can be used during the selection of a compiler. # +# If ERRFILE is provided, any contents of the stderr will be placed +# in ERRFILE, which should be deleted by the caller. +# # Test that resulting file is executable; see the problem reported by mwoehlke # in <http://lists.gnu.org/archive/html/bug-coreutils/2006-10/msg00048.html>. # But skip the test when cross-compiling, to prevent problems like the one @@ -2715,6 +2727,7 @@ AC_DEFUN([_AC_LINK_IFELSE], [$0_BODY])]dnl [m4_ifvaln([$1], [AC_LANG_CONFTEST([$1])])]dnl [AS_IF([ac_fn_[]_AC_LANG_ABBREV[]_try_link "$LINENO"], [$2], [$3]) +m4_ifvaln([$4], [cp conftest.err "$4"]) rm -f core conftest.err conftest.$ac_objext \ conftest$ac_exeext[]m4_ifval([$1], [ conftest.$ac_ext])[]dnl ])# _AC_LINK_IFELSE diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4 index 318f621..b14c4d3 100644 --- a/lib/autoconf/lang.m4 +++ b/lib/autoconf/lang.m4 @@ -729,3 +729,272 @@ 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 <gui...@gmx.de> +# Copyright (c) 2011 Maarten Bosmans <mkbosm...@gmail.com> +# + +#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 +])# 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. 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 <gui...@gmx.de> +# Copyright (c) 2010 Rhys Ulerich <rhys.uler...@gmail.com> +# +# NOTE (Implementation Tactics) +# +# The for-argument contains a list of options. The first part of +# these does only exist to detect the compiler - usually it is +# a global option to enable -ansi or -extrawarnings. All other +# compilers will fail about it. That was needed since a lot of +# compilers will give false positives for some option-syntax +# like -Woption or -Xoption as they think of it is a pass-through +# to later compile stages or something. The "%" is used as a +# delimiter. A non-option comment can be given after "%%" marks +# which will be shown but not added to the respective C/CXXFLAGS. + +#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,$1,FLAGS) for _AC_LANG compiler default warnings], +VAR,[VAR="no, unknown" +ac_save_[]FLAGS="$[]FLAGS" +for ac_arg dnl +in "-xHost % -Wall -w3" dnl Intel + "-pedantic -Wunreachable-code % -Wall -Wunreachable-code" dnl gcc/clang + "-pedantic % -Wall" dnl gcc when it no longer silently ignores -Wunreachable-code + "-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_IF([enable_default_warning_flags], + [no], + [VAR="no, disabled per request"], + [VAR=m4_ifvaln($3,["no, disabled per request"],[$VAR])] + ) +]) +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 +])# AC_FLAGS_WARN_ALL + + +# SYNOPSIS +# +# _AC_COMPILER_OPTION_IFELSE(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED]) +# +# DESCRIPTION +# +# Check if the compiler supports OPTION when compiling and linking. +# Executes IF-SUPPORTED if supported, and executes IF-NOT-SUPPORTED if a +# non-zero exit status or option-specific stderr output occurs. +# +# NOTE +# +# Copied and modified from gnulib warnings.m4 module, which was authored by +# Simon Josefsson +AC_DEFUN([_AC_COMPILER_OPTION_IFELSE], +[AS_VAR_PUSHDEF([ac_Warn], [ac_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl +AS_VAR_PUSHDEF([ac_Flags], [_AC_LANG_PREFIX[][FLAGS]])dnl +AS_LITERAL_IF([$1], + [m4_pushdef([ac_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))], + [ac_Positive="$1" +case $ac_Positive in + -Wno-*) ac_Positive=-W`expr "X$ac_Positive" : 'X-Wno-\(.*\)'` ;; +esac +m4_pushdef([ac_Positive], [$ac_Positive])])dnl +AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([ac_Warn]), [ + ac_save_compiler_FLAGS="$ac_Flags" + AS_VAR_APPEND(m4_defn([ac_Flags]), + [" $ac_unknown_warnings_are_errors ]m4_defn([ac_Positive])["]) + _AC_LINK_IFELSE([AC_LANG_PROGRAM], + [AS_VAR_SET([ac_Warn], [yes])], + [AS_VAR_SET([ac_Warn], [no])], + [conftest.err1]) + ac_Flags="$ac_save_compiler_FLAGS" + AS_VAR_IF([ac_Warn], [yes], [ + # This stderr output check is due to compilers like Intel icc/icpc that + # will only issue warnings to stderr for unknown flags, never exiting with + # non-zero status. + AS_VAR_PUSHDEF([ac_linecount1], [ac_cv_linecount1_[]_AC_LANG_ABBREV[]_$1])dnl + ac_linecount1=`sed -n '$=' conftest.err1` + _AC_LINK_IFELSE([AC_LANG_PROGRAM], [], [], [conftest.err2]) + AS_VAR_PUSHDEF([ac_linecount2], [ac_cv_linecount2_[]_AC_LANG_ABBREV[]_$1])dnl + ac_linecount2=`sed -n '$=' conftest.err2` + AS_IF([test "$ac_linecount1" != "$ac_linecount2"], + [AS_VAR_PUSHDEF([ac_Pattern], [ac_cv_pattern_$1])dnl + ac_Pattern=`printf "%s " "$1" | sed ['s/[, ].*//']` + AS_IF([diff conftest.err1 conftest.err2 | grep -- "$ac_Pattern" >/dev/null 2>&1], + [AS_VAR_SET([ac_Warn], [no]) + AS_VAR_POPDEF([ac_Pattern]) + ]) + ]) + AS_VAR_POPDEF([ac_linecount2]) + AS_VAR_POPDEF([ac_linecount1]) + ]) +]) +AS_VAR_IF([ac_Warn], [yes], [$2], [$3]) +rm -f conftest.err1 conftest.err2 +m4_popdef([ac_Positive])dnl +AS_VAR_POPDEF([ac_Flags])dnl +AS_VAR_POPDEF([ac_Warn])dnl +])# _AC_COMPILER_OPTION_IFELSE + +# DESCRIPTION +# +# Forces LLVM compiler to complain about unknown flags. +# Required by _AC_APPEND_FLAG_IFVALID. +# +# NOTE +# +# Copied and modified from gnulib warnings.m4 module, which was authored by +# Simon Josefsson +AC_DEFUN([_AC_UNKNOWN_WARNINGS_ARE_ERRORS], +[# Clang doesn't complain about unknown warning options unless one also + # specifies -Wunknown-warning-option -Werror. Detect this. + _AC_COMPILER_OPTION_IFELSE([-Werror -Wunknown-warning-option], + [ac_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'], + [ac_unknown_warnings_are_errors=]) + ])# _AC_UNKNOWN_WARNINGS_ARE_ERRORS + +# SYNOPSIS +# +# AC_APPEND_CFLAG_IFVALID(OPTION) +# AC_APPEND_CXXFLAG_IFVALID(OPTION) +# AC_APPEND_FCFLAG_IFVALID(OPTION) +# +# DESCRIPTION +# +# Adds OPTION parameter to FLAGS if the compiler supports it when +# compiling PROGRAM. For example, AC_APPENDFLAG_IFVALID([-Wparentheses]). +# +# NOTE +# +# Copied and modified from gnulib warnings.m4 module, which was authored by +# Simon Josefsson +AC_DEFUN([AC_APPEND_FLAG_IFVALID],[dnl +AS_VAR_PUSHDEF([FLAGS],[_AC_LANG_PREFIX[]FLAGS])dnl +AC_REQUIRE([_AC_UNKNOWN_WARNINGS_ARE_ERRORS]) +_AC_COMPILER_OPTION_IFELSE([$1], + [AC_APPEND_FLAG([$1])], + []) +AS_VAR_POPDEF([FLAGS])dnl +])# AC_APPEND_FLAG_IFVALID + +AC_DEFUN([AC_APPEND_CFLAG_IFVALID],[dnl +AC_LANG_PUSH([C]) +AC_APPEND_FLAG_IFVALID([$1]) +AC_LANG_POP([C]) +])# AC_APPEND_CFLAG_IFVALID + +AC_DEFUN([AC_APPEND_CXXFLAG_IFVALID],[dnl +AC_LANG_PUSH([C++]) +AC_APPEND_FLAG_IFVALID([$1]) +AC_LANG_POP([C++]) +])# AC_APPEND_CXXFLAG_IFVALID + +AC_DEFUN([AC_APPEND_FCFLAG_IFVALID],[dnl +AC_LANG_PUSH([Fortran]) +AC_APPEND_FLAG_IFVALID([$1]) +AC_LANG_POP([Fortran]) +])# AC_APPEND_FCFLAG_IFVALID + +AC_DEFUN([AC_CFLAGS_WARN_ALL],[dnl +AC_LANG_PUSH([C]) +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4]) +AC_LANG_POP([C]) +])# AC_CFLAGS_WARN_ALL + +AC_DEFUN([AC_CXXFLAGS_WARN_ALL],[dnl +AC_LANG_PUSH([C++]) +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4]) +AC_LANG_POP([C++]) +])# AC_CXXFLAGS_WARN_ALL + +AC_DEFUN([AC_FCFLAGS_WARN_ALL],[dnl +AC_LANG_PUSH([Fortran]) +AC_FLAGS_WARN_ALL([$1], [$2], [$3], [$4]) +AC_LANG_POP([Fortran]) +])# AC_FCFLAGS_WARN_ALL