Since checking all those warning flags takes an amount of time I find irritating, here is an attempt at caching the results of checking compiler warning flag support
A couple of aspects which need definitely need review or testing: * I've tried to get things right when not the first flag in the list of alternates is supported, but this really needs testing with a compiler other than gcc * The cache variable naming policy is a bit opaque me, so the names used may need corecting * I've tried to be careful, but who knows what portability sins I have committed :-) This change reduces the time to run the ./configure script produced from a configure.ac containing just AC_INIT([test], 1.0) XORG_COMPILER_FLAGS XORG_CWARNFLAGS XORG_STRICT_OPTION AC_OUTPUT() from ~60s to ~20s on my cygwin machine, and from ~15s to ~9s on a linux VM running on the same hardware Signed-off-by: Jon TURNEY <[email protected]> --- xorg-macros.m4.in | 36 +++++++++++++++++++++++------------- 1 files changed, 23 insertions(+), 13 deletions(-) diff --git a/xorg-macros.m4.in b/xorg-macros.m4.in index 8197eb6..e6582cb 100644 --- a/xorg-macros.m4.in +++ b/xorg-macros.m4.in @@ -1450,6 +1450,7 @@ AC_CHECK_DECL([__SUNPRO_C], [SUNCC="yes"], [SUNCC="no"]) # AC_DEFUN([XORG_TESTSET_CFLAG], [ AC_REQUIRE([AC_PROG_CC_C99]) +AC_REQUIRE([AC_PROG_SED]) m4_if([$#], 0, [m4_fatal([XORG_TESTSET_CFLAG was given with an unsupported number of arguments])]) m4_if([$#], 1, [m4_fatal([XORG_TESTSET_CFLAG was given with an unsupported number of arguments])]) @@ -1457,11 +1458,12 @@ xorg_testset_save_CFLAGS="$CFLAGS" if test "x$xorg_testset_unknown_warning_option" = "x" ; then CFLAGS="$CFLAGS -Werror=unknown-warning-option" - AC_MSG_CHECKING([if $CC supports -Werror=unknown-warning-option]) - AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], - [xorg_testset_unknown_warning_option=yes], - [xorg_testset_unknown_warning_option=no]) - AC_MSG_RESULT([$xorg_testset_unknown_warning_option]) + AC_CACHE_CHECK([if $CC supports -Werror=unknown-warning-option], + xorg_cv_cc_flag_unknown_warning_option, + AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], + [xorg_cv_cc_flag_unknown_warning_option=yes], + [xorg_cv_cc_flag_unknown_warning_option=no])) + xorg_testset_unknown_warning_option=$xorg_cv_cc_flag_unknown_warning_option CFLAGS="$xorg_testset_save_CFLAGS" fi @@ -1470,11 +1472,12 @@ if test "x$xorg_testset_unused_command_line_argument" = "x" ; then CFLAGS="$CFLAGS -Werror=unknown-warning-option" fi CFLAGS="$CFLAGS -Werror=unused-command-line-argument" - AC_MSG_CHECKING([if $CC supports -Werror=unused-command-line-argument]) - AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], - [xorg_testset_unused_command_line_argument=yes], - [xorg_testset_unused_command_line_argument=no]) - AC_MSG_RESULT([$xorg_testset_unused_command_line_argument]) + AC_CACHE_CHECK([if $CC supports -Werror=unused-command-line-argument], + xorg_cv_cc_flag_unused_command_line_argument, + AC_COMPILE_IFELSE([AC_LANG_SOURCE([int i;])], + [xorg_cv_cc_flag_unused_command_line_argument=yes], + [xorg_cv_cc_flag_unused_command_line_argument=no])) + xorg_testset_unused_command_line_argument=$xorg_cv_cc_flag_unused_command_line_argument CFLAGS="$xorg_testset_save_CFLAGS" fi @@ -1491,12 +1494,19 @@ m4_foreach([flag], m4_cdr($@), [ CFLAGS="$CFLAGS ]flag[" +dnl Some hackery here since AC_CACHE_VAL can't handle a non-literal varname and +dnl flag may contains spaces as it may contain multiple flags, but a cacheid can't AC_MSG_CHECKING([if $CC supports ]flag[]) - AC_LINK_IFELSE([AC_LANG_PROGRAM([int i;])], - [supported=yes], [supported=no]) - AC_MSG_RESULT([$supported]) + cacheid=`AS_ECHO_N([xorg_cv_cc_flag_]flag[]) | $SED 's/ /_/'` + AC_CACHE_VAL(AS_TR_SH($cacheid), + [AC_LINK_IFELSE([AC_LANG_PROGRAM([int i;])], + [eval AS_TR_SH($cacheid)=yes], + [eval AS_TR_SH($cacheid)=no])]) + CFLAGS="$xorg_testset_save_CFLAGS" + eval supported=$AS_TR_SH($cacheid) + AC_MSG_RESULT([$supported]) if test "$supported" = "yes" ; then $1="$$1 ]flag[" found="yes" -- 1.7.5.1 _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
