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authorReid Spencer <rspencer@reidspencer.com>2004-12-27 06:14:48 +0000
committerReid Spencer <rspencer@reidspencer.com>2004-12-27 06:14:48 +0000
commit5d01fa5bbe82504e2977d9152c619303e65c839c (patch)
tree9b52a2188b85349cc96bb9712c2c85a787a67a4e /autoconf/m4/need_dev_zero_for_mmap.m4
parent3ed2f2f27a6f303a0da7c52db54134876624bc24 (diff)
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For PR351:
Provide a check to determine if /dev/zero is needed for AllocateRWX function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19147 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'autoconf/m4/need_dev_zero_for_mmap.m4')
-rw-r--r--autoconf/m4/need_dev_zero_for_mmap.m417
1 files changed, 17 insertions, 0 deletions
diff --git a/autoconf/m4/need_dev_zero_for_mmap.m4 b/autoconf/m4/need_dev_zero_for_mmap.m4
new file mode 100644
index 0000000000..352c5186db
--- /dev/null
+++ b/autoconf/m4/need_dev_zero_for_mmap.m4
@@ -0,0 +1,17 @@
+#
+# When allocating RWX memory, check whether we need to use /dev/zero
+# as the file descriptor or not.
+#
+AC_DEFUN([AC_NEED_DEV_ZERO_FOR_MMAP],
+[AC_CACHE_CHECK([if /dev/zero is needed for mmap],
+ac_cv_need_dev_zero_for_mmap,
+[if test "$llvm_cv_os_type" == "Interix" ; then
+ ac_cv_need_dev_zero_for_mmap=yes
+ else
+ ac_cv_need_dev_zero_for_mmap=no
+ fi
+])
+if test "$ac_cv_need_dev_zero_for_mmap" = yes; then
+ AC_DEFINE([NEED_DEV_ZERO_FOR_MMAP],[1],
+ [Define if /dev/zero should be used when mapping RWX memory, or undefine if its not necessary])
+fi])