[PATCH macros] Cache the results of checking compiler flag support in XORG_TESTSET_CFLAG
Jon TURNEY
jon.turney at dronecode.org.uk
Mon Jan 2 11:42:10 PST 2012
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
v2: AS_TR_SH transforms characters which are invalid in shell variable names, so we don't
have to use sed to transform spaces ourself
Signed-off-by: Jon TURNEY <jon.turney at dronecode.org.uk>
---
xorg-macros.m4.in | 34 +++++++++++++++++++++-------------
1 files changed, 21 insertions(+), 13 deletions(-)
diff --git a/xorg-macros.m4.in b/xorg-macros.m4.in
index 8197eb6..9e6acf5 100644
--- a/xorg-macros.m4.in
+++ b/xorg-macros.m4.in
@@ -1457,11 +1457,12 @@ 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="$xorg_testset_save_CFLAGS"
fi
@@ -1470,11 +1471,12 @@ if test "x$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="$xorg_testset_save_CFLAGS"
fi
@@ -1491,12 +1493,18 @@ m4_foreach([flag], m4_cdr($@), [
CFLAGS="$CFLAGS ]flag["
+dnl Some hackery here since AC_CACHE_VAL can't handle a non-literal varname
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[])`
+ 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
--------------060401010104080103060509--
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