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1 # mmap-anon.m4 serial 8 | 1 # mmap-anon.m4 serial 10 |
2 dnl Copyright (C) 2005, 2007, 2009-2011 Free Software Foundation, Inc. | 2 dnl Copyright (C) 2005, 2007, 2009-2012 Free Software Foundation, Inc. |
3 dnl This file is free software; the Free Software Foundation | 3 dnl This file is free software; the Free Software Foundation |
4 dnl gives unlimited permission to copy and/or distribute it, | 4 dnl gives unlimited permission to copy and/or distribute it, |
5 dnl with or without modifications, as long as this notice is preserved. | 5 dnl with or without modifications, as long as this notice is preserved. |
6 | 6 |
7 # Detect how mmap can be used to create anonymous (not file-backed) memory | 7 # Detect how mmap can be used to create anonymous (not file-backed) memory |
8 # mappings. | 8 # mappings. |
9 # - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS | 9 # - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS |
10 # and MAP_ANON exist and have the same value. | 10 # and MAP_ANON exist and have the same value. |
11 # - On HP-UX, only MAP_ANONYMOUS exists. | 11 # - On HP-UX, only MAP_ANONYMOUS exists. |
12 # - On MacOS X, FreeBSD, NetBSD, OpenBSD, only MAP_ANON exists. | 12 # - On Mac OS X, FreeBSD, NetBSD, OpenBSD, only MAP_ANON exists. |
13 # - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be | 13 # - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be |
14 # used. | 14 # used. |
15 | 15 |
16 AC_DEFUN([gl_FUNC_MMAP_ANON], | 16 AC_DEFUN([gl_FUNC_MMAP_ANON], |
17 [ | 17 [ |
18 dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57. | |
19 AC_REQUIRE([AC_PROG_CPP]) | |
20 AC_REQUIRE([AC_PROG_EGREP]) | |
21 | |
22 dnl Persuade glibc <sys/mman.h> to define MAP_ANONYMOUS. | 18 dnl Persuade glibc <sys/mman.h> to define MAP_ANONYMOUS. |
23 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) | 19 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) |
24 | 20 |
25 # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it | 21 # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it |
26 # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is | 22 # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is |
27 # irrelevant for anonymous mappings. | 23 # irrelevant for anonymous mappings. |
28 AC_CHECK_FUNC([mmap], [gl_have_mmap=yes], [gl_have_mmap=no]) | 24 AC_CHECK_FUNC([mmap], [gl_have_mmap=yes], [gl_have_mmap=no]) |
29 | 25 |
30 # Try to allow MAP_ANONYMOUS. | 26 # Try to allow MAP_ANONYMOUS. |
31 gl_have_mmap_anonymous=no | 27 gl_have_mmap_anonymous=no |
32 if test $gl_have_mmap = yes; then | 28 if test $gl_have_mmap = yes; then |
33 AC_MSG_CHECKING([for MAP_ANONYMOUS]) | 29 AC_MSG_CHECKING([for MAP_ANONYMOUS]) |
34 AC_EGREP_CPP([I cant identify this map.], [ | 30 AC_EGREP_CPP([I cannot identify this map], [ |
35 #include <sys/mman.h> | 31 #include <sys/mman.h> |
36 #ifdef MAP_ANONYMOUS | 32 #ifdef MAP_ANONYMOUS |
37 I cant identify this map. | 33 I cannot identify this map |
38 #endif | 34 #endif |
39 ], | 35 ], |
40 [gl_have_mmap_anonymous=yes]) | 36 [gl_have_mmap_anonymous=yes]) |
41 if test $gl_have_mmap_anonymous != yes; then | 37 if test $gl_have_mmap_anonymous != yes; then |
42 AC_EGREP_CPP([I cant identify this map.], [ | 38 AC_EGREP_CPP([I cannot identify this map], [ |
43 #include <sys/mman.h> | 39 #include <sys/mman.h> |
44 #ifdef MAP_ANON | 40 #ifdef MAP_ANON |
45 I cant identify this map. | 41 I cannot identify this map |
46 #endif | 42 #endif |
47 ], | 43 ], |
48 [AC_DEFINE([MAP_ANONYMOUS], [MAP_ANON], | 44 [AC_DEFINE([MAP_ANONYMOUS], [MAP_ANON], |
49 [Define to a substitute value for mmap()'s MAP_ANONYMOUS flag.]) | 45 [Define to a substitute value for mmap()'s MAP_ANONYMOUS flag.]) |
50 gl_have_mmap_anonymous=yes]) | 46 gl_have_mmap_anonymous=yes]) |
51 fi | 47 fi |
52 AC_MSG_RESULT([$gl_have_mmap_anonymous]) | 48 AC_MSG_RESULT([$gl_have_mmap_anonymous]) |
53 if test $gl_have_mmap_anonymous = yes; then | 49 if test $gl_have_mmap_anonymous = yes; then |
54 AC_DEFINE([HAVE_MAP_ANONYMOUS], [1], | 50 AC_DEFINE([HAVE_MAP_ANONYMOUS], [1], |
55 [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available after including | 51 [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available after including |
56 config.h and <sys/mman.h>.]) | 52 config.h and <sys/mman.h>.]) |
57 fi | 53 fi |
58 fi | 54 fi |
59 ]) | 55 ]) |
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