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AX_CFLAGS_GCC_OPTION ([shellvar], optionflag [,A/NA])
1.4 (2003/10/28) 0.5.55 : untested, experimental
Guido Draheim <guidod@gmx.de>
AX_CFLAGS_GCC_OPTION(-fvomit-frame) would show a message as like "checking CFLAGS for gcc -fvomit-frame ... yes" and adds the optionflag to CFLAGS if it is understood. You can override the shellvar-default of CFLAGS of course. The order of arguments stems from the explicit macros like AX_CFLAGS_WARN_ALL.
The cousin AX_CXXFLAGS_GCC_OPTION would check for an option to add to CXXFLAGS - and it uses the autoconf setup for C++ instead of C (since it is possible to use different compilers for C and C++).
The macro is a lot simpler than any special AX_CFLAGS_* macro (or ac_cxx_rtti.m4 macro) but allows to check for arbitrary options. However, if you use this macro in a few places, it would be great if you would make up a new function-macro and submit it to the ac-archive.
- $1 shell-variable-to-add-to : CFLAGS
- $2 option-to-check-for : required ("-option" as non-value)
- $3 action-if-found : add value to shellvariable
- $4 action-if-not-found : nothing
AC_DEFUN([AX_CFLAGS_GCC_OPTION], [dnl AS_VAR_PUSHDEF([FLAGS],[CFLAGS])dnl AS_VAR_PUSHDEF([VAR],[ac_cv_cflags_gcc_option_$2])dnl AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for gcc m4_ifval($2,$2,-option)], VAR,[VAR="no, unknown" AC_LANG_SAVE AC_LANG_C ac_save_[]FLAGS="$[]FLAGS" for ac_arg dnl in "-pedantic % m4_ifval($2,$2,-option)" dnl GCC # do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'` AC_TRY_COMPILE([],[return 0;], [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break]) done FLAGS="$ac_save_[]FLAGS" AC_LANG_RESTORE ]) case ".$VAR" in .ok|.ok,*) m4_ifvaln($3,$3) ;; .|.no|.no,*) m4_ifvaln($4,$4) ;; *) m4_ifvaln($3,$3,[ if echo " $[]m4_ifval($1,$1,FLAGS) " | grep " $VAR " 2>&1 >/dev/null then AC_RUN_LOG([: m4_ifval($1,$1,FLAGS) does contain $VAR]) else AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"]) m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR" fi ]) ;; esac AS_VAR_POPDEF([VAR])dnl AS_VAR_POPDEF([FLAGS])dnl ]) dnl the only difference - the LANG selection... and the default FLAGS AC_DEFUN([AX_CXXFLAGS_GCC_OPTION], [dnl AS_VAR_PUSHDEF([FLAGS],[CXXFLAGS])dnl AS_VAR_PUSHDEF([VAR],[ac_cv_cxxflags_gcc_option_$2])dnl AC_CACHE_CHECK([m4_ifval($1,$1,FLAGS) for gcc m4_ifval($2,$2,-option)], VAR,[VAR="no, unknown" AC_LANG_SAVE AC_LANG_CXX ac_save_[]FLAGS="$[]FLAGS" for ac_arg dnl in "-pedantic % m4_ifval($2,$2,-option)" dnl GCC # do FLAGS="$ac_save_[]FLAGS "`echo $ac_arg | sed -e 's,%%.*,,' -e 's,%,,'` AC_TRY_COMPILE([],[return 0;], [VAR=`echo $ac_arg | sed -e 's,.*% *,,'` ; break]) done FLAGS="$ac_save_[]FLAGS" AC_LANG_RESTORE ]) case ".$VAR" in .ok|.ok,*) m4_ifvaln($3,$3) ;; .|.no|.no,*) m4_ifvaln($4,$4) ;; *) m4_ifvaln($3,$3,[ if echo " $[]m4_ifval($1,$1,FLAGS) " | grep " $VAR " 2>&1 >/dev/null then AC_RUN_LOG([: m4_ifval($1,$1,FLAGS) does contain $VAR]) else AC_RUN_LOG([: m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR"]) m4_ifval($1,$1,FLAGS)="$m4_ifval($1,$1,FLAGS) $VAR" fi ]) ;; esac AS_VAR_POPDEF([VAR])dnl AS_VAR_POPDEF([FLAGS])dnl ])