[patch] weaken the MMAP check

[patch] weaken the MMAP check

[Andreas Tobler]

Hello,

this patch weakens the MMAP check. We only need MMAP with mmap chosen 
address ranges, no FIXED one. On HP-UX PA MAP_FIXED does not work.
To run gcj_dbtool we fail here on HP-UX PA with an mmap not implemented 
exception. This patch makes it work.

Ok for trunk ?

Andreas

2006-04-17  Andreas Tobler  <a.tobler@schweiz.ch>

	* configure.ac: Weaken the check for MMAP.
	* configure: Rebuilt.


Index: configure.ac
===================================================================
--- configure.ac        (revision 113010)
+++ configure.ac        (working copy)
@@ -1346,8 +1346,32 @@
            [AC_MSG_RESULT(no)])])])

  AC_FUNC_ALLOCA
-AC_FUNC_MMAP

+dnl Check for mmap()
+# AC_FUNC_MMAP goes to far and checks for mmap fixed, we do only need mmap
+# at a mmap selected address. See
+# gnu/java/nio/channels/natFileChannelPosix.cc
+
+AC_MSG_CHECKING([for mmap])
+AC_CACHE_VAL(ac_cv_func_mmap_ok,
+    [AC_TRY_LINK(
+    changequote(<<, >>)dnl
+    <<
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+    >>,
+    changequote([, ])dnl
+    [mmap((void *)0, 0, PROT_READ, 0, 0, 0);],
+    ac_cv_func_mmap_ok=yes,
+    ac_cv_func_mmap_ok=no)] )
+AC_MSG_RESULT($ac_cv_func_mmap_ok)
+if test $ac_cv_func_mmap_ok = yes
+then
+  AC_DEFINE(HAVE_MMAP, 1, [ Define to 1 if you have a working `mmap' 
system call w/o fixed address ability.])
+fi
+
  AC_CHECK_PROGS(PERL, perl, false)

  SYSDEP_SOURCES=

Re: [patch] weaken the MMAP check

[Tom Tromey]

>>>>> "Andreas" == Andreas Tobler <toa@pop.agri.ch> writes:

Andreas> this patch weakens the MMAP check. We only need MMAP with mmap chosen
Andreas> address ranges, no FIXED one. On HP-UX PA MAP_FIXED does not work.
Andreas> To run gcj_dbtool we fail here on HP-UX PA with an mmap not
Andreas> implemented exception. This patch makes it work.

Andreas> Ok for trunk ?

Ok, thanks.

Tom

Re: [patch] weaken the MMAP check

[Andreas Tobler]

Tom Tromey wrote:
>>>>>> "Andreas" == Andreas Tobler <toa@pop.agri.ch> writes:
> 
> Andreas> this patch weakens the MMAP check. We only need MMAP with mmap chosen
> Andreas> address ranges, no FIXED one. On HP-UX PA MAP_FIXED does not work.
> Andreas> To run gcj_dbtool we fail here on HP-UX PA with an mmap not
> Andreas> implemented exception. This patch makes it work.
> 
> Andreas> Ok for trunk ?
> 
> Ok, thanks.

Thank you Tom.

I'll check in after an additional build & test since I discovered that I 
have to run autoheader too and that it removes the HAVE_GETPAGESIZE from 
include/config.h.in (seems to come from AC_FUNC_MMAP).

Andreas


2006-04-22  Andreas Tobler  <a.tobler@schweiz.ch>

	* configure.ac: Weaken the check for MMAP.
	* configure: Rebuilt.
	* include/config.h.in: Likewise.

Re: [patch] weaken the MMAP check

[Tom Tromey]

>>>>> "Andreas" == Andreas Tobler <toa@pop.agri.ch> writes:

Andreas> I'll check in after an additional build & test since I discovered that
Andreas> I have to run autoheader too and that it removes the HAVE_GETPAGESIZE
Andreas> from include/config.h.in (seems to come from AC_FUNC_MMAP).

In this case you have to add another check for getpagesize.
The symbol HAVE_GETPAGESIZE is actually used in a couple of places.

Tom

Re: [patch] weaken the MMAP check

[Andreas Tobler]

Hi Tom,

Tom Tromey wrote:
>>>>>> "Andreas" == Andreas Tobler <toa@pop.agri.ch> writes:
> 
> Andreas> I'll check in after an additional build & test since I discovered that
> Andreas> I have to run autoheader too and that it removes the HAVE_GETPAGESIZE
> Andreas> from include/config.h.in (seems to come from AC_FUNC_MMAP).
> 
> In this case you have to add another check for getpagesize.
> The symbol HAVE_GETPAGESIZE is actually used in a couple of places.

Well, in the libgcj core directory I can't find any instance of 
HAVE_GETPAGESIZE.
In the classpath sub directory, yes. But there we check again for 
getpagesize and mmap, but with a different method. (AC_CHECK_FUNCS)

Andreas

Re: [patch] weaken the MMAP check

[Tom Tromey]

>>>>> "Andreas" == Andreas Tobler <toa@pop.agri.ch> writes:

Andreas> Well, in the libgcj core directory I can't find any instance of
Andreas> HAVE_GETPAGESIZE.

Oh, oops -- I misread the grep output the first time.
Things are fine as they are.

Tom