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authormrs <mrs@138bc75d-0d04-0410-961f-82ee72b054a4>2005-04-07 23:26:05 +0000
committermrs <mrs@138bc75d-0d04-0410-961f-82ee72b054a4>2005-04-07 23:26:05 +0000
commit8979cff9ea16e8f8503c48827449df3f6dae84e1 (patch)
treed60ea2b5d164788d7a5e57b8836d29692a036859 /libtool.m4
parent058aec75949d13d3ba3fcc8041475f0de626aec1 (diff)
downloadgcc-8979cff9ea16e8f8503c48827449df3f6dae84e1.tar.gz
* libtool.m4: Update AC_LIBTOOL_SYS_MAX_CMD_LEN bits from upstream.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@97808 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libtool.m4')
-rw-r--r--libtool.m481
1 files changed, 81 insertions, 0 deletions
diff --git a/libtool.m4 b/libtool.m4
index 60121579faf..3e170d19cdb 100644
--- a/libtool.m4
+++ b/libtool.m4
@@ -103,6 +103,8 @@ AC_REQUIRE([AC_OBJEXT])dnl
AC_REQUIRE([AC_EXEEXT])dnl
dnl
+AC_LIBTOOL_SYS_MAX_CMD_LEN
+
# Only perform the check for file, if the check method requires it
case $deplibs_check_method in
file_magic*)
@@ -279,6 +281,85 @@ ifdef([AC_PROVIDE_AC_LIBTOOL_WIN32_DLL],
esac
])
+
+# AC_LIBTOOL_SYS_MAX_CMD_LEN
+# --------------------------
+AC_DEFUN([AC_LIBTOOL_SYS_MAX_CMD_LEN],
+[# find the maximum length of command line arguments
+AC_MSG_CHECKING([the maximum length of command line arguments])
+AC_CACHE_VAL([lt_cv_sys_max_cmd_len], [dnl
+ i=0
+ teststring="ABCD"
+
+ case $build_os in
+ msdosdjgpp*)
+ # On DJGPP, this test can blow up pretty badly due to problems in libc
+ # (any single argument exceeding 2000 bytes causes a buffer overrun
+ # during glob expansion). Even if it were fixed, the result of this
+ # check would be larger than it should be.
+ lt_cv_sys_max_cmd_len=12288; # 12K is about right
+ ;;
+
+ cygwin* | mingw*)
+ # On Win9x/ME, this test blows up -- it succeeds, but takes
+ # about 5 minutes as the teststring grows exponentially.
+ # Worse, since 9x/ME are not pre-emptively multitasking,
+ # you end up with a "frozen" computer, even though with patience
+ # the test eventually succeeds (with a max line length of 256k).
+ # Instead, let's just punt: use the minimum linelength reported by
+ # all of the supported platforms: 8192 (on NT/2K/XP).
+ lt_cv_sys_max_cmd_len=8192;
+ ;;
+
+ amigaos*)
+ # On AmigaOS with pdksh, this test takes hours, literally.
+ # So we just punt and use a minimum line length of 8192.
+ lt_cv_sys_max_cmd_len=8192;
+ ;;
+
+ netbsd* | freebsd* | openbsd* | darwin* | dragonfly*)
+ # This has been around since 386BSD, at least. Likely further.
+ if test -x /sbin/sysctl; then
+ lt_cv_sys_max_cmd_len=`/sbin/sysctl -n kern.argmax`
+ elif test -x /usr/sbin/sysctl; then
+ lt_cv_sys_max_cmd_len=`/usr/sbin/sysctl -n kern.argmax`
+ else
+ lt_cv_sys_max_cmd_len=65536 # usable default for *BSD
+ fi
+ # And add a safety zone
+ lt_cv_sys_max_cmd_len=`expr $lt_cv_sys_max_cmd_len \/ 4`
+ lt_cv_sys_max_cmd_len=`expr $lt_cv_sys_max_cmd_len \* 3`
+ ;;
+ *)
+ # If test is not a shell built-in, we'll probably end up computing a
+ # maximum length that is only half of the actual maximum length, but
+ # we can't tell.
+ SHELL=${SHELL-${CONFIG_SHELL-/bin/sh}}
+ while (test "X"`$SHELL [$]0 --fallback-echo "X$teststring" 2>/dev/null` \
+ = "XX$teststring") >/dev/null 2>&1 &&
+ new_result=`expr "X$teststring" : ".*" 2>&1` &&
+ lt_cv_sys_max_cmd_len=$new_result &&
+ test $i != 17 # 1/2 MB should be enough
+ do
+ i=`expr $i + 1`
+ teststring=$teststring$teststring
+ done
+ teststring=
+ # Add a significant safety factor because C++ compilers can tack on massive
+ # amounts of additional arguments before passing them to the linker.
+ # It appears as though 1/2 is a usable value.
+ lt_cv_sys_max_cmd_len=`expr $lt_cv_sys_max_cmd_len \/ 2`
+ ;;
+ esac
+])
+if test -n $lt_cv_sys_max_cmd_len ; then
+ AC_MSG_RESULT($lt_cv_sys_max_cmd_len)
+else
+ AC_MSG_RESULT(none)
+fi
+])# AC_LIBTOOL_SYS_MAX_CMD_LEN
+
+
# AC_LIBTOOL_DLOPEN - enable checks for dlopen support
AC_DEFUN([AC_LIBTOOL_DLOPEN], [AC_BEFORE([$0],[AC_LIBTOOL_SETUP])])