projects / deliverable / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| 40a73391 | 1 | # mmap-anon.m4 serial 10 |
| c0c3707f | 2 | dnl Copyright (C) 2005, 2007, 2009-2019 Free Software Foundation, Inc. |
| f434ba03 PA |
3 | dnl This file is free software; the Free Software Foundation |
| 4 | dnl gives unlimited permission to copy and/or distribute it, | |
| 5 | dnl with or without modifications, as long as this notice is preserved. | |
| 6 | ||
| 7 | # Detect how mmap can be used to create anonymous (not file-backed) memory | |
| 8 | # mappings. | |
| 9 | # - On Linux, AIX, OSF/1, Solaris, Cygwin, Interix, Haiku, both MAP_ANONYMOUS | |
| 10 | # and MAP_ANON exist and have the same value. | |
| 11 | # - On HP-UX, only MAP_ANONYMOUS exists. | |
| 40a73391 | 12 | # - On Mac OS X, FreeBSD, NetBSD, OpenBSD, only MAP_ANON exists. |
| f434ba03 PA |
13 | # - On IRIX, neither exists, and a file descriptor opened to /dev/zero must be |
| 14 | # used. | |
| 15 | ||
| 16 | AC_DEFUN([gl_FUNC_MMAP_ANON], | |
| 17 | [ | |
| f434ba03 PA |
18 | dnl Persuade glibc <sys/mman.h> to define MAP_ANONYMOUS. |
| 19 | AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) | |
| 20 | ||
| 21 | # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it | |
| 22 | # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is | |
| 23 | # irrelevant for anonymous mappings. | |
| 24 | AC_CHECK_FUNC([mmap], [gl_have_mmap=yes], [gl_have_mmap=no]) | |
| 25 | ||
| 26 | # Try to allow MAP_ANONYMOUS. | |
| 27 | gl_have_mmap_anonymous=no | |
| 28 | if test $gl_have_mmap = yes; then | |
| 29 | AC_MSG_CHECKING([for MAP_ANONYMOUS]) | |
| 40a73391 | 30 | AC_EGREP_CPP([I cannot identify this map], [ |
| f434ba03 PA |
31 | #include <sys/mman.h> |
| 32 | #ifdef MAP_ANONYMOUS | |
| 40a73391 | 33 | I cannot identify this map |
| f434ba03 PA |
34 | #endif |
| 35 | ], | |
| 36 | [gl_have_mmap_anonymous=yes]) | |
| 37 | if test $gl_have_mmap_anonymous != yes; then | |
| 40a73391 | 38 | AC_EGREP_CPP([I cannot identify this map], [ |
| f434ba03 PA |
39 | #include <sys/mman.h> |
| 40 | #ifdef MAP_ANON | |
| 40a73391 | 41 | I cannot identify this map |
| f434ba03 PA |
42 | #endif |
| 43 | ], | |
| 44 | [AC_DEFINE([MAP_ANONYMOUS], [MAP_ANON], | |
| 45 | [Define to a substitute value for mmap()'s MAP_ANONYMOUS flag.]) | |
| 46 | gl_have_mmap_anonymous=yes]) | |
| 47 | fi | |
| 48 | AC_MSG_RESULT([$gl_have_mmap_anonymous]) | |
| 49 | if test $gl_have_mmap_anonymous = yes; then | |
| 50 | AC_DEFINE([HAVE_MAP_ANONYMOUS], [1], | |
| 51 | [Define to 1 if mmap()'s MAP_ANONYMOUS flag is available after including | |
| 52 | config.h and <sys/mman.h>.]) | |
| 53 | fi | |
| 54 | fi | |
| 55 | ]) |