common/autoconf/boot-jdk.m4 - platform/libcore - Git at Google

 #
 # Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License version 2 only, as
 # published by the Free Software Foundation.  Oracle designates this
 # particular file as subject to the "Classpath" exception as provided
 # by Oracle in the LICENSE file that accompanied this code.
 #
 # This code is distributed in the hope that it will be useful, but WITHOUT
 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 # version 2 for more details (a copy is included in the LICENSE file that
 # accompanied this code).
 #
 # You should have received a copy of the GNU General Public License version
 # 2 along with this work; if not, write to the Free Software Foundation,
 # Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 # Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 # or visit www.oracle.com if you need additional information or have any
 # questions.
 #

 # Execute the check given as argument, and verify the result
 # If the Boot JDK was previously found, do nothing
 # $1 A command line (typically autoconf macro) to execute
 AC_DEFUN([BOOTJDK_DO_CHECK],
 [
   if test "x$BOOT_JDK_FOUND" = xno; then
     # Now execute the test
     $1

     # If previous step claimed to have found a JDK, check it to see if it seems to be valid.
     if test "x$BOOT_JDK_FOUND" = xmaybe; then
       # Do we have a bin/java?
       if test ! -x "$BOOT_JDK/bin/java"; then
         AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain bin/java; ignoring])
         BOOT_JDK_FOUND=no
       else
         # Do we have a bin/javac?
         if test ! -x "$BOOT_JDK/bin/javac"; then
           AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain bin/javac; ignoring])
           AC_MSG_NOTICE([(This might be an JRE instead of an JDK)])
           BOOT_JDK_FOUND=no
         else
           # Do we have an rt.jar? (On MacOSX it is called classes.jar)
           if test ! -f "$BOOT_JDK/jre/lib/rt.jar" && test ! -f "$BOOT_JDK/../Classes/classes.jar"; then
             AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain an rt.jar; ignoring])
             BOOT_JDK_FOUND=no
           else
             # Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
             BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 | head -n 1`

             # Extra M4 quote needed to protect [] in grep expression.
             [FOUND_VERSION_78=`echo $BOOT_JDK_VERSION | grep  '\"1\.[78]\.'`]
             if test "x$FOUND_VERSION_78" = x; then
               AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK is incorrect JDK version ($BOOT_JDK_VERSION); ignoring])
               AC_MSG_NOTICE([(Your Boot JDK must be version 7 or 8)])
               BOOT_JDK_FOUND=no
             else
               # We're done! :-)
               BOOT_JDK_FOUND=yes
               BASIC_FIXUP_PATH(BOOT_JDK)
               AC_MSG_CHECKING([for Boot JDK])
               AC_MSG_RESULT([$BOOT_JDK])
               AC_MSG_CHECKING([Boot JDK version])
               BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 | $TR '\n\r' '  '`
               AC_MSG_RESULT([$BOOT_JDK_VERSION])
             fi # end check jdk version
           fi # end check rt.jar
         fi # end check javac
       fi # end check java
     fi # end check boot jdk found
   fi
 ])

 # Test: Is bootjdk explicitely set by command line arguments?
 AC_DEFUN([BOOTJDK_CHECK_ARGUMENTS],
 [
 if test "x$with_boot_jdk" != x; then
     BOOT_JDK=$with_boot_jdk
     BOOT_JDK_FOUND=maybe
     AC_MSG_NOTICE([Found potential Boot JDK using configure arguments])
 fi
 ])

 # Test: Is bootjdk available from builddeps?
 AC_DEFUN([BOOTJDK_CHECK_BUILDDEPS],
 [
     BDEPS_CHECK_MODULE(BOOT_JDK, bootjdk, xxx, [BOOT_JDK_FOUND=maybe], [BOOT_JDK_FOUND=no])
 ])

 # Test: Is $JAVA_HOME set?
 AC_DEFUN([BOOTJDK_CHECK_JAVA_HOME],
 [
     if test "x$JAVA_HOME" != x; then
         JAVA_HOME_PROCESSED="$JAVA_HOME"
         BASIC_FIXUP_PATH(JAVA_HOME_PROCESSED)
         if test ! -d "$JAVA_HOME_PROCESSED"; then
             AC_MSG_NOTICE([Your JAVA_HOME points to a non-existing directory!])
         else
           # Aha, the user has set a JAVA_HOME
           # let us use that as the Boot JDK.
           BOOT_JDK="$JAVA_HOME_PROCESSED"
           BOOT_JDK_FOUND=maybe
           AC_MSG_NOTICE([Found potential Boot JDK using JAVA_HOME])
         fi
     fi
 ])

 # Test: Is there a java or javac in the PATH, which is a symlink to the JDK?
 AC_DEFUN([BOOTJDK_CHECK_JAVA_IN_PATH_IS_SYMLINK],
 [
     AC_PATH_PROG(JAVAC_CHECK, javac)
     AC_PATH_PROG(JAVA_CHECK, java)
     BINARY="$JAVAC_CHECK"
     if test "x$JAVAC_CHECK" = x; then
         BINARY="$JAVA_CHECK"
     fi
     if test "x$BINARY" != x; then
         # So there is a java(c) binary, it might be part of a JDK.
         # Lets find the JDK/JRE directory by following symbolic links.
         # Linux/GNU systems often have links from /usr/bin/java to
         # /etc/alternatives/java to the real JDK binary.
         BASIC_REMOVE_SYMBOLIC_LINKS(BINARY)
         BOOT_JDK=`dirname "$BINARY"`
         BOOT_JDK=`cd "$BOOT_JDK/.."; pwd`
         if test -x "$BOOT_JDK/bin/javac" && test -x "$BOOT_JDK/bin/java"; then
             # Looks like we found ourselves an JDK
             BOOT_JDK_FOUND=maybe
             AC_MSG_NOTICE([Found potential Boot JDK using java(c) in PATH])
         fi
     fi
 ])

 # Test: Is there a /usr/libexec/java_home? (Typically on MacOSX)
 AC_DEFUN([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME],
 [
     if test -x /usr/libexec/java_home; then
         BOOT_JDK=`/usr/libexec/java_home`
         BOOT_JDK_FOUND=maybe
         AC_MSG_NOTICE([Found potential Boot JDK using /usr/libexec/java_home])
     fi
 ])

 # Look for a jdk in the given path. If there are multiple, try to select the newest.
 # If found, set BOOT_JDK and BOOT_JDK_FOUND.
 # $1 = Path to directory containing jdk installations.
 # $2 = String to append to the found JDK directory to get the proper JDK home
 AC_DEFUN([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY],
 [
   BOOT_JDK_PREFIX="$1"
   BOOT_JDK_SUFFIX="$2"
   ALL_JDKS_FOUND=`$LS "$BOOT_JDK_PREFIX" 2> /dev/null | $SORT -r`
   if test "x$ALL_JDKS_FOUND" != x; then
     for JDK_TO_TRY in $ALL_JDKS_FOUND ; do
       BOOTJDK_DO_CHECK([
         BOOT_JDK="${BOOT_JDK_PREFIX}/${JDK_TO_TRY}${BOOT_JDK_SUFFIX}"
         if test -d "$BOOT_JDK"; then
           BOOT_JDK_FOUND=maybe
           AC_MSG_NOTICE([Found potential Boot JDK using well-known locations (in $BOOT_JDK_PREFIX/$JDK_TO_TRY)])
         fi
       ])
     done
   fi
 ])

 # Call BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY, but use the given
 # environmental variable as base for where to look.
 # $1 Name of an environmal variable, assumed to point to the Program Files directory.
 AC_DEFUN([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY],
 [
   if test "x[$]$1" != x; then
     VIRTUAL_DIR="[$]$1/Java"
     BASIC_WINDOWS_REWRITE_AS_UNIX_PATH(VIRTUAL_DIR)
     BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY($VIRTUAL_DIR)
   fi
 ])

 # Test: Is there a JDK installed in default, well-known locations?
 AC_DEFUN([BOOTJDK_CHECK_WELL_KNOWN_LOCATIONS],
 [
   if test "x$OPENJDK_TARGET_OS" = xwindows; then
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([ProgramW6432])])
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([PROGRAMW6432])])
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([PROGRAMFILES])])
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([ProgramFiles])])
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/cygdrive/c/Program Files/Java])])
   elif test "x$OPENJDK_TARGET_OS" = xmacosx; then
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/Library/Java/JavaVirtualMachines],[/Contents/Home])])
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/System/Library/Java/JavaVirtualMachines],[/Contents/Home])])
   elif test "x$OPENJDK_TARGET_OS" = xlinux; then
     BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/usr/lib/jvm])])
   fi
 ])

 # Check that a command-line tool in the Boot JDK is correct
 # $1 = name of variable to assign
 # $2 = name of binary
 AC_DEFUN([BOOTJDK_CHECK_TOOL_IN_BOOTJDK],
 [
   AC_MSG_CHECKING([for $2 in Boot JDK])
   $1=$BOOT_JDK/bin/$2
   if test ! -x [$]$1; then
       AC_MSG_RESULT(not found)
       AC_MSG_NOTICE([Your Boot JDK seems broken. This might be fixed by explicitely setting --with-boot-jdk])
       AC_MSG_ERROR([Could not find $2 in the Boot JDK])
   fi
   AC_MSG_RESULT(ok)
 ])

 ###############################################################################
 #
 # We need a Boot JDK to bootstrap the build.
 #

 AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK],
 [
 BOOT_JDK_FOUND=no
 AC_ARG_WITH(boot-jdk, [AS_HELP_STRING([--with-boot-jdk],
     [path to Boot JDK (used to bootstrap build) @<:@probed@:>@])])

 # We look for the Boot JDK through various means, going from more certain to
 # more of a guess-work. After each test, BOOT_JDK_FOUND is set to "yes" if
 # we detected something (if so, the path to the jdk is in BOOT_JDK). But we
 # must check if this is indeed valid; otherwise we'll continue looking.

 # Test: Is bootjdk explicitely set by command line arguments?
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_ARGUMENTS])
 if test "x$with_boot_jdk" != x && test "x$BOOT_JDK_FOUND" = xno; then
   # Having specified an argument which is incorrect will produce an instant failure;
   # we should not go on looking
   AC_MSG_ERROR([The path given by --with-boot-jdk does not contain a valid Boot JDK])
 fi

 # Test: Is bootjdk available from builddeps?
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_BUILDDEPS])

 # Test: Is $JAVA_HOME set?
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_HOME])

 # Test: Is there a /usr/libexec/java_home? (Typically on MacOSX)
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME])

 # Test: Is there a java or javac in the PATH, which is a symlink to the JDK?
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_IN_PATH_IS_SYMLINK])

 # Test: Is there a JDK installed in default, well-known locations?
 BOOTJDK_DO_CHECK([BOOTJDK_CHECK_WELL_KNOWN_LOCATIONS])

 # If we haven't found anything yet, we've truly lost. Give up.
 if test "x$BOOT_JDK_FOUND" = xno; then
   HELP_MSG_MISSING_DEPENDENCY([openjdk])
   AC_MSG_NOTICE([Could not find a valid Boot JDK. $HELP_MSG])
   AC_MSG_NOTICE([This might be fixed by explicitely setting --with-boot-jdk])
   AC_MSG_ERROR([Cannot continue])
 fi

 # Setup proper paths for what we found
 BOOT_RTJAR="$BOOT_JDK/jre/lib/rt.jar"
 if test ! -f "$BOOT_RTJAR"; then
     # On MacOSX it is called classes.jar
     BOOT_RTJAR="$BOOT_JDK/../Classes/classes.jar"
     if test -f "$BOOT_RTJAR"; then
       # Remove the ..
       BOOT_RTJAR="`cd ${BOOT_RTJAR%/*} && pwd`/${BOOT_RTJAR##*/}"
     fi
 fi
 BOOT_TOOLSJAR="$BOOT_JDK/lib/tools.jar"
 BOOT_JDK="$BOOT_JDK"
 AC_SUBST(BOOT_RTJAR)
 AC_SUBST(BOOT_TOOLSJAR)
 AC_SUBST(BOOT_JDK)

 # Setup tools from the Boot JDK.
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVA,java)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAC,javac)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAH,javah)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAP,javap)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAR,jar)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(RMIC,rmic)
 BOOTJDK_CHECK_TOOL_IN_BOOTJDK(NATIVE2ASCII,native2ascii)

 # Finally, set some other options...

 # When compiling code to be executed by the Boot JDK, force jdk7 compatibility.
 BOOT_JDK_SOURCETARGET="-source 7 -target 7"
 AC_SUBST(BOOT_JDK_SOURCETARGET)
 AC_SUBST(JAVAC_FLAGS)
 ])

 AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK_ARGUMENTS],
 [
 ##############################################################################
 #
 # Specify options for anything that is run with the Boot JDK.
 #
 AC_ARG_WITH(boot-jdk-jvmargs, [AS_HELP_STRING([--with-boot-jdk-jvmargs],
 	[specify JVM arguments to be passed to all invocations of the Boot JDK, overriding the default values,
      e.g --with-boot-jdk-jvmargs="-Xmx8G -enableassertions"])])

 if test "x$with_boot_jdk_jvmargs" = x; then
     # Not all JVM:s accept the same arguments on the command line.
     # OpenJDK specific increase in thread stack for JDK build,
     # well more specifically, when running javac.
     if test "x$BUILD_NUM_BITS" = x32; then
        STACK_SIZE=768
     else
        # Running Javac on a JVM on a 64-bit machine, the stack takes more space
        # since 64-bit pointers are pushed on the stach. Apparently, we need
        # to increase the stack space when javacing the JDK....
        STACK_SIZE=1536
     fi

     # Minimum amount of heap memory.
     ADD_JVM_ARG_IF_OK([-Xms64M],boot_jdk_jvmargs,[$JAVA])
     if test "x$OPENJDK_TARGET_OS" = "xmacosx"; then
         # Why does macosx need more heap? Its the huge JDK batch.
         ADD_JVM_ARG_IF_OK([-Xmx1600M],boot_jdk_jvmargs,[$JAVA])
     else
         ADD_JVM_ARG_IF_OK([-Xmx1100M],boot_jdk_jvmargs,[$JAVA])
     fi
     # When is adding -client something that speeds up the JVM?
     # ADD_JVM_ARG_IF_OK([-client],boot_jdk_jvmargs,[$JAVA])
     ADD_JVM_ARG_IF_OK([-XX:PermSize=32m],boot_jdk_jvmargs,[$JAVA])
     ADD_JVM_ARG_IF_OK([-XX:MaxPermSize=160m],boot_jdk_jvmargs,[$JAVA])
     ADD_JVM_ARG_IF_OK([-XX:ThreadStackSize=$STACK_SIZE],boot_jdk_jvmargs,[$JAVA])
     # Disable special log output when a debug build is used as Boot JDK...
     ADD_JVM_ARG_IF_OK([-XX:-PrintVMOptions -XX:-UnlockDiagnosticVMOptions -XX:-LogVMOutput],boot_jdk_jvmargs,[$JAVA])
 fi

 AC_SUBST(BOOT_JDK_JVMARGS, $boot_jdk_jvmargs)
 ])
	#
	# Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
	# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	#
	# This code is free software; you can redistribute it and/or modify it
	# under the terms of the GNU General Public License version 2 only, as
	# published by the Free Software Foundation. Oracle designates this
	# particular file as subject to the "Classpath" exception as provided
	# by Oracle in the LICENSE file that accompanied this code.
	#
	# This code is distributed in the hope that it will be useful, but WITHOUT
	# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	# version 2 for more details (a copy is included in the LICENSE file that
	# accompanied this code).
	#
	# You should have received a copy of the GNU General Public License version
	# 2 along with this work; if not, write to the Free Software Foundation,
	# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	#
	# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	# or visit www.oracle.com if you need additional information or have any
	# questions.
	#

	# Execute the check given as argument, and verify the result
	# If the Boot JDK was previously found, do nothing
	# $1 A command line (typically autoconf macro) to execute
	AC_DEFUN([BOOTJDK_DO_CHECK],
	[
	if test "x$BOOT_JDK_FOUND" = xno; then
	# Now execute the test
	$1

	# If previous step claimed to have found a JDK, check it to see if it seems to be valid.
	if test "x$BOOT_JDK_FOUND" = xmaybe; then
	# Do we have a bin/java?
	if test ! -x "$BOOT_JDK/bin/java"; then
	AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain bin/java; ignoring])
	BOOT_JDK_FOUND=no
	else
	# Do we have a bin/javac?
	if test ! -x "$BOOT_JDK/bin/javac"; then
	AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain bin/javac; ignoring])
	AC_MSG_NOTICE([(This might be an JRE instead of an JDK)])
	BOOT_JDK_FOUND=no
	else
	# Do we have an rt.jar? (On MacOSX it is called classes.jar)
	if test ! -f "$BOOT_JDK/jre/lib/rt.jar" && test ! -f "$BOOT_JDK/../Classes/classes.jar"; then
	AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK did not contain an rt.jar; ignoring])
	BOOT_JDK_FOUND=no
	else
	# Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
	BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 \| head -n 1`

	# Extra M4 quote needed to protect [] in grep expression.
	[FOUND_VERSION_78=`echo $BOOT_JDK_VERSION \| grep '\"1\.[78]\.'`]
	if test "x$FOUND_VERSION_78" = x; then
	AC_MSG_NOTICE([Potential Boot JDK found at $BOOT_JDK is incorrect JDK version ($BOOT_JDK_VERSION); ignoring])
	AC_MSG_NOTICE([(Your Boot JDK must be version 7 or 8)])
	BOOT_JDK_FOUND=no
	else
	# We're done! :-)
	BOOT_JDK_FOUND=yes
	BASIC_FIXUP_PATH(BOOT_JDK)
	AC_MSG_CHECKING([for Boot JDK])
	AC_MSG_RESULT([$BOOT_JDK])
	AC_MSG_CHECKING([Boot JDK version])
	BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 \| $TR '\n\r' ' '`
	AC_MSG_RESULT([$BOOT_JDK_VERSION])
	fi # end check jdk version
	fi # end check rt.jar
	fi # end check javac
	fi # end check java
	fi # end check boot jdk found
	fi
	])

	# Test: Is bootjdk explicitely set by command line arguments?
	AC_DEFUN([BOOTJDK_CHECK_ARGUMENTS],
	[
	if test "x$with_boot_jdk" != x; then
	BOOT_JDK=$with_boot_jdk
	BOOT_JDK_FOUND=maybe
	AC_MSG_NOTICE([Found potential Boot JDK using configure arguments])
	fi
	])

	# Test: Is bootjdk available from builddeps?
	AC_DEFUN([BOOTJDK_CHECK_BUILDDEPS],
	[
	BDEPS_CHECK_MODULE(BOOT_JDK, bootjdk, xxx, [BOOT_JDK_FOUND=maybe], [BOOT_JDK_FOUND=no])
	])

	# Test: Is $JAVA_HOME set?
	AC_DEFUN([BOOTJDK_CHECK_JAVA_HOME],
	[
	if test "x$JAVA_HOME" != x; then
	JAVA_HOME_PROCESSED="$JAVA_HOME"
	BASIC_FIXUP_PATH(JAVA_HOME_PROCESSED)
	if test ! -d "$JAVA_HOME_PROCESSED"; then
	AC_MSG_NOTICE([Your JAVA_HOME points to a non-existing directory!])
	else
	# Aha, the user has set a JAVA_HOME
	# let us use that as the Boot JDK.
	BOOT_JDK="$JAVA_HOME_PROCESSED"
	BOOT_JDK_FOUND=maybe
	AC_MSG_NOTICE([Found potential Boot JDK using JAVA_HOME])
	fi
	fi
	])

	# Test: Is there a java or javac in the PATH, which is a symlink to the JDK?
	AC_DEFUN([BOOTJDK_CHECK_JAVA_IN_PATH_IS_SYMLINK],
	[
	AC_PATH_PROG(JAVAC_CHECK, javac)
	AC_PATH_PROG(JAVA_CHECK, java)
	BINARY="$JAVAC_CHECK"
	if test "x$JAVAC_CHECK" = x; then
	BINARY="$JAVA_CHECK"
	fi
	if test "x$BINARY" != x; then
	# So there is a java(c) binary, it might be part of a JDK.
	# Lets find the JDK/JRE directory by following symbolic links.
	# Linux/GNU systems often have links from /usr/bin/java to
	# /etc/alternatives/java to the real JDK binary.
	BASIC_REMOVE_SYMBOLIC_LINKS(BINARY)
	BOOT_JDK=`dirname "$BINARY"`
	BOOT_JDK=`cd "$BOOT_JDK/.."; pwd`
	if test -x "$BOOT_JDK/bin/javac" && test -x "$BOOT_JDK/bin/java"; then
	# Looks like we found ourselves an JDK
	BOOT_JDK_FOUND=maybe
	AC_MSG_NOTICE([Found potential Boot JDK using java(c) in PATH])
	fi
	fi
	])

	# Test: Is there a /usr/libexec/java_home? (Typically on MacOSX)
	AC_DEFUN([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME],
	[
	if test -x /usr/libexec/java_home; then
	BOOT_JDK=`/usr/libexec/java_home`
	BOOT_JDK_FOUND=maybe
	AC_MSG_NOTICE([Found potential Boot JDK using /usr/libexec/java_home])
	fi
	])

	# Look for a jdk in the given path. If there are multiple, try to select the newest.
	# If found, set BOOT_JDK and BOOT_JDK_FOUND.
	# $1 = Path to directory containing jdk installations.
	# $2 = String to append to the found JDK directory to get the proper JDK home
	AC_DEFUN([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY],
	[
	BOOT_JDK_PREFIX="$1"
	BOOT_JDK_SUFFIX="$2"
	ALL_JDKS_FOUND=`$LS "$BOOT_JDK_PREFIX" 2> /dev/null \| $SORT -r`
	if test "x$ALL_JDKS_FOUND" != x; then
	for JDK_TO_TRY in $ALL_JDKS_FOUND ; do
	BOOTJDK_DO_CHECK([
	BOOT_JDK="${BOOT_JDK_PREFIX}/${JDK_TO_TRY}${BOOT_JDK_SUFFIX}"
	if test -d "$BOOT_JDK"; then
	BOOT_JDK_FOUND=maybe
	AC_MSG_NOTICE([Found potential Boot JDK using well-known locations (in $BOOT_JDK_PREFIX/$JDK_TO_TRY)])
	fi
	])
	done
	fi
	])

	# Call BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY, but use the given
	# environmental variable as base for where to look.
	# $1 Name of an environmal variable, assumed to point to the Program Files directory.
	AC_DEFUN([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY],
	[
	if test "x[$]$1" != x; then
	VIRTUAL_DIR="[$]$1/Java"
	BASIC_WINDOWS_REWRITE_AS_UNIX_PATH(VIRTUAL_DIR)
	BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY($VIRTUAL_DIR)
	fi
	])

	# Test: Is there a JDK installed in default, well-known locations?
	AC_DEFUN([BOOTJDK_CHECK_WELL_KNOWN_LOCATIONS],
	[
	if test "x$OPENJDK_TARGET_OS" = xwindows; then
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([ProgramW6432])])
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([PROGRAMW6432])])
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([PROGRAMFILES])])
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_WINDOWS_VIRTUAL_DIRECTORY([ProgramFiles])])
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/cygdrive/c/Program Files/Java])])
	elif test "x$OPENJDK_TARGET_OS" = xmacosx; then
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/Library/Java/JavaVirtualMachines],[/Contents/Home])])
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/System/Library/Java/JavaVirtualMachines],[/Contents/Home])])
	elif test "x$OPENJDK_TARGET_OS" = xlinux; then
	BOOTJDK_DO_CHECK([BOOTJDK_FIND_BEST_JDK_IN_DIRECTORY([/usr/lib/jvm])])
	fi
	])

	# Check that a command-line tool in the Boot JDK is correct
	# $1 = name of variable to assign
	# $2 = name of binary
	AC_DEFUN([BOOTJDK_CHECK_TOOL_IN_BOOTJDK],
	[
	AC_MSG_CHECKING([for $2 in Boot JDK])
	$1=$BOOT_JDK/bin/$2
	if test ! -x [$]$1; then
	AC_MSG_RESULT(not found)
	AC_MSG_NOTICE([Your Boot JDK seems broken. This might be fixed by explicitely setting --with-boot-jdk])
	AC_MSG_ERROR([Could not find $2 in the Boot JDK])
	fi
	AC_MSG_RESULT(ok)
	])

	###############################################################################
	#
	# We need a Boot JDK to bootstrap the build.
	#

	AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK],
	[
	BOOT_JDK_FOUND=no
	AC_ARG_WITH(boot-jdk, [AS_HELP_STRING([--with-boot-jdk],
	[path to Boot JDK (used to bootstrap build) @<:@probed@:>@])])

	# We look for the Boot JDK through various means, going from more certain to
	# more of a guess-work. After each test, BOOT_JDK_FOUND is set to "yes" if
	# we detected something (if so, the path to the jdk is in BOOT_JDK). But we
	# must check if this is indeed valid; otherwise we'll continue looking.

	# Test: Is bootjdk explicitely set by command line arguments?
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_ARGUMENTS])
	if test "x$with_boot_jdk" != x && test "x$BOOT_JDK_FOUND" = xno; then
	# Having specified an argument which is incorrect will produce an instant failure;
	# we should not go on looking
	AC_MSG_ERROR([The path given by --with-boot-jdk does not contain a valid Boot JDK])
	fi

	# Test: Is bootjdk available from builddeps?
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_BUILDDEPS])

	# Test: Is $JAVA_HOME set?
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_HOME])

	# Test: Is there a /usr/libexec/java_home? (Typically on MacOSX)
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME])

	# Test: Is there a java or javac in the PATH, which is a symlink to the JDK?
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_IN_PATH_IS_SYMLINK])

	# Test: Is there a JDK installed in default, well-known locations?
	BOOTJDK_DO_CHECK([BOOTJDK_CHECK_WELL_KNOWN_LOCATIONS])

	# If we haven't found anything yet, we've truly lost. Give up.
	if test "x$BOOT_JDK_FOUND" = xno; then
	HELP_MSG_MISSING_DEPENDENCY([openjdk])
	AC_MSG_NOTICE([Could not find a valid Boot JDK. $HELP_MSG])
	AC_MSG_NOTICE([This might be fixed by explicitely setting --with-boot-jdk])
	AC_MSG_ERROR([Cannot continue])
	fi

	# Setup proper paths for what we found
	BOOT_RTJAR="$BOOT_JDK/jre/lib/rt.jar"
	if test ! -f "$BOOT_RTJAR"; then
	# On MacOSX it is called classes.jar
	BOOT_RTJAR="$BOOT_JDK/../Classes/classes.jar"
	if test -f "$BOOT_RTJAR"; then
	# Remove the ..
	BOOT_RTJAR="`cd ${BOOT_RTJAR%/} && pwd`/${BOOT_RTJAR##/}"
	fi
	fi
	BOOT_TOOLSJAR="$BOOT_JDK/lib/tools.jar"
	BOOT_JDK="$BOOT_JDK"
	AC_SUBST(BOOT_RTJAR)
	AC_SUBST(BOOT_TOOLSJAR)
	AC_SUBST(BOOT_JDK)

	# Setup tools from the Boot JDK.
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVA,java)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAC,javac)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAH,javah)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAP,javap)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAR,jar)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(RMIC,rmic)
	BOOTJDK_CHECK_TOOL_IN_BOOTJDK(NATIVE2ASCII,native2ascii)

	# Finally, set some other options...

	# When compiling code to be executed by the Boot JDK, force jdk7 compatibility.
	BOOT_JDK_SOURCETARGET="-source 7 -target 7"
	AC_SUBST(BOOT_JDK_SOURCETARGET)
	AC_SUBST(JAVAC_FLAGS)
	])

	AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK_ARGUMENTS],
	[
	##############################################################################
	#
	# Specify options for anything that is run with the Boot JDK.
	#
	AC_ARG_WITH(boot-jdk-jvmargs, [AS_HELP_STRING([--with-boot-jdk-jvmargs],
	[specify JVM arguments to be passed to all invocations of the Boot JDK, overriding the default values,
	e.g --with-boot-jdk-jvmargs="-Xmx8G -enableassertions"])])

	if test "x$with_boot_jdk_jvmargs" = x; then
	# Not all JVM:s accept the same arguments on the command line.
	# OpenJDK specific increase in thread stack for JDK build,
	# well more specifically, when running javac.
	if test "x$BUILD_NUM_BITS" = x32; then
	STACK_SIZE=768
	else
	# Running Javac on a JVM on a 64-bit machine, the stack takes more space
	# since 64-bit pointers are pushed on the stach. Apparently, we need
	# to increase the stack space when javacing the JDK....
	STACK_SIZE=1536
	fi

	# Minimum amount of heap memory.
	ADD_JVM_ARG_IF_OK([-Xms64M],boot_jdk_jvmargs,[$JAVA])
	if test "x$OPENJDK_TARGET_OS" = "xmacosx"; then
	# Why does macosx need more heap? Its the huge JDK batch.
	ADD_JVM_ARG_IF_OK([-Xmx1600M],boot_jdk_jvmargs,[$JAVA])
	else
	ADD_JVM_ARG_IF_OK([-Xmx1100M],boot_jdk_jvmargs,[$JAVA])
	fi
	# When is adding -client something that speeds up the JVM?
	# ADD_JVM_ARG_IF_OK([-client],boot_jdk_jvmargs,[$JAVA])
	ADD_JVM_ARG_IF_OK([-XX:PermSize=32m],boot_jdk_jvmargs,[$JAVA])
	ADD_JVM_ARG_IF_OK([-XX:MaxPermSize=160m],boot_jdk_jvmargs,[$JAVA])
	ADD_JVM_ARG_IF_OK([-XX:ThreadStackSize=$STACK_SIZE],boot_jdk_jvmargs,[$JAVA])
	# Disable special log output when a debug build is used as Boot JDK...
	ADD_JVM_ARG_IF_OK([-XX:-PrintVMOptions -XX:-UnlockDiagnosticVMOptions -XX:-LogVMOutput],boot_jdk_jvmargs,[$JAVA])
	fi

	AC_SUBST(BOOT_JDK_JVMARGS, $boot_jdk_jvmargs)
	])