make/autoconf/boot-jdk.m4
changeset 47216 71c04702a3d5
parent 45051 676afd13dea5
child 47254 ff97a658de30
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/autoconf/boot-jdk.m4	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,541 @@
+#
+# Copyright (c) 2011, 2017, 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.
+#
+
+########################################################################
+# This file handles detection of the Boot JDK. The Boot JDK detection
+# process has been developed as a response to solve a complex real-world
+# problem. Initially, it was simple, but it has grown as platform after
+# platform, idiosyncracy after idiosyncracy has been supported.
+#
+# The basic idea is this:
+# 1) You need an acceptable *) JDK to use as a Boot JDK
+# 2) There are several ways to locate a JDK, that are mostly platform
+#    dependent **)
+# 3) You can have multiple JDKs installed
+# 4) If possible, configure should try to dig out an acceptable JDK
+#    automatically, without having to resort to command-line options
+#
+# *)  acceptable means e.g. JDK7 for building JDK8, a complete JDK (with
+#     javac) and not a JRE, etc.
+#
+# **) On Windows we typically use a well-known path.
+#     On MacOSX we typically use the tool java_home.
+#     On Linux we typically find javac in the $PATH, and then follow a
+#     chain of symlinks that often ends up in a real JDK.
+#
+# This leads to the code where we check in different ways to locate a
+# JDK, and if one is found, check if it is acceptable. If not, we print
+# our reasons for rejecting it (useful when debugging non-working
+# configure situations) and continue checking the next one.
+########################################################################
+
+# 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 $BOOT_JDK did not contain bin/javac; ignoring])
+          AC_MSG_NOTICE([(This might be an JRE instead of an JDK)])
+          BOOT_JDK_FOUND=no
+        else
+          # Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
+          BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 | $HEAD -n 1`
+
+          # Extra M4 quote needed to protect [] in grep expression.
+          [FOUND_CORRECT_VERSION=`$ECHO $BOOT_JDK_VERSION | $EGREP '\"9([\.+-].*)?\"|(1\.[89]\.)'`]
+          if test "x$FOUND_CORRECT_VERSION" = 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 8 or 9)])
+            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 javac
+      fi # end check java
+    fi # end check boot jdk found
+  fi
+])
+
+# Test: Is bootjdk explicitly 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 $JAVA_HOME set?
+AC_DEFUN([BOOTJDK_CHECK_JAVA_HOME],
+[
+  if test "x$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)
+# $1: Argument to the java_home binary (optional)
+AC_DEFUN([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME],
+[
+  if test -x /usr/libexec/java_home; then
+    BOOT_JDK=`/usr/libexec/java_home $1`
+    BOOT_JDK_FOUND=maybe
+    AC_MSG_NOTICE([Found potential Boot JDK using /usr/libexec/java_home $1])
+  fi
+])
+
+# Test: On MacOS X, can we find a boot jdk using /usr/libexec/java_home?
+AC_DEFUN([BOOTJDK_CHECK_MACOSX_JAVA_LOCATOR],
+[
+  if test "x$OPENJDK_TARGET_OS" = xmacosx; then
+    # First check at user selected default
+    BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME()])
+    # If that did not work out (e.g. too old), try explicit versions instead
+    BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME([-v 1.9])])
+    BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME([-v 1.8])])
+    BOOTJDK_DO_CHECK([BOOTJDK_CHECK_LIBEXEC_JAVA_HOME([-v 1.7])])
+  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],
+[
+  # Use user overridden value if available, otherwise locate tool in the Boot JDK.
+  BASIC_SETUP_TOOL($1,
+    [
+      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 explicitly setting --with-boot-jdk])
+        AC_MSG_ERROR([Could not find $2 in the Boot JDK])
+      fi
+      AC_MSG_RESULT(ok)
+      AC_SUBST($1)
+    ])
+])
+
+###############################################################################
+#
+# We need a Boot JDK to bootstrap the build.
+#
+
+AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK],
+[
+  BOOT_JDK_FOUND=no
+  AC_ARG_WITH(boot-jdk, [AS_HELP_STRING([--with-boot-jdk],
+      [path to Boot JDK (used to bootstrap build) @<:@probed@:>@])])
+
+  # We look for the Boot JDK through various means, going from more certain to
+  # more of a guess-work. After each test, BOOT_JDK_FOUND is set to "yes" if
+  # we detected something (if so, the path to the jdk is in BOOT_JDK). But we
+  # must check if this is indeed valid; otherwise we'll continue looking.
+
+  # Test: Is bootjdk explicitly set by command line arguments?
+  BOOTJDK_DO_CHECK([BOOTJDK_CHECK_ARGUMENTS])
+  if test "x$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: On MacOS X, can we find a boot jdk using /usr/libexec/java_home?
+  BOOTJDK_DO_CHECK([BOOTJDK_CHECK_MACOSX_JAVA_LOCATOR])
+
+  # Test: Is $JAVA_HOME set?
+  BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_HOME])
+
+  # Test: Is there a java or javac in the PATH, which is a symlink to the JDK?
+  BOOTJDK_DO_CHECK([BOOTJDK_CHECK_JAVA_IN_PATH_IS_SYMLINK])
+
+  # Test: Is there a JDK installed in default, well-known locations?
+  BOOTJDK_DO_CHECK([BOOTJDK_CHECK_WELL_KNOWN_LOCATIONS])
+
+  # If we haven't found anything yet, we've truly lost. Give up.
+  if test "x$BOOT_JDK_FOUND" = xno; then
+    HELP_MSG_MISSING_DEPENDENCY([openjdk])
+    AC_MSG_NOTICE([Could not find a valid Boot JDK. $HELP_MSG])
+    AC_MSG_NOTICE([This might be fixed by explicitly setting --with-boot-jdk])
+    AC_MSG_ERROR([Cannot continue])
+  fi
+
+  AC_SUBST(BOOT_JDK)
+
+  # Setup tools from the Boot JDK.
+  BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVA, java)
+  BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAC, javac)
+  BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAVAH, javah)
+  BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JAR, jar)
+  BOOTJDK_CHECK_TOOL_IN_BOOTJDK(JARSIGNER, jarsigner)
+
+  # Finally, set some other options...
+
+  # When compiling code to be executed by the Boot JDK, force jdk8 compatibility.
+  BOOT_JDK_SOURCETARGET="-source 8 -target 8"
+  AC_SUBST(BOOT_JDK_SOURCETARGET)
+
+  AC_MSG_CHECKING([if Boot JDK supports modules])
+  if "$JAVA" --list-modules > /dev/null 2>&1; then
+    AC_MSG_RESULT([yes])
+    BOOT_JDK_MODULAR="true"
+  else
+    AC_MSG_RESULT([no])
+    BOOT_JDK_MODULAR="false"
+  fi
+  AC_SUBST(BOOT_JDK_MODULAR)
+
+  AC_SUBST(JAVAC_FLAGS)
+
+  # Check if the boot jdk is 32 or 64 bit
+  if "$JAVA" -version 2>&1 | $GREP -q "64-Bit"; then
+    BOOT_JDK_BITS="64"
+  else
+    BOOT_JDK_BITS="32"
+  fi
+  AC_MSG_CHECKING([if Boot JDK is 32 or 64 bits])
+  AC_MSG_RESULT([$BOOT_JDK_BITS])
+])
+
+AC_DEFUN_ONCE([BOOTJDK_SETUP_BOOT_JDK_ARGUMENTS],
+[
+  ##############################################################################
+  #
+  # Specify jvm options for anything that is run with the Boot JDK.
+  # Not all JVM:s accept the same arguments on the command line.
+  #
+  AC_ARG_WITH(boot-jdk-jvmargs, [AS_HELP_STRING([--with-boot-jdk-jvmargs],
+  [specify JVM arguments to be passed to all java invocations of boot JDK, overriding the default values,
+  e.g --with-boot-jdk-jvmargs="-Xmx8G -enableassertions"])])
+
+  AC_MSG_CHECKING([flags for boot jdk java command] )
+
+  # 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,[$JAVA])
+
+  # Force en-US environment
+  ADD_JVM_ARG_IF_OK([-Duser.language=en -Duser.country=US],boot_jdk_jvmargs,[$JAVA])
+
+  # Apply user provided options.
+  ADD_JVM_ARG_IF_OK([$with_boot_jdk_jvmargs],boot_jdk_jvmargs,[$JAVA])
+
+  AC_MSG_RESULT([$boot_jdk_jvmargs])
+
+  # For now, general JAVA_FLAGS are the same as the boot jdk jvmargs
+  JAVA_FLAGS=$boot_jdk_jvmargs
+  AC_SUBST(JAVA_FLAGS)
+
+
+  AC_MSG_CHECKING([flags for boot jdk java command for big workloads])
+
+  # Starting amount of heap memory.
+  ADD_JVM_ARG_IF_OK([-Xms64M],boot_jdk_jvmargs_big,[$JAVA])
+  BOOTCYCLE_JVM_ARGS_BIG=-Xms64M
+
+  # Maximum amount of heap memory and stack size.
+  JVM_HEAP_LIMIT_32="1024"
+  # Running a 64 bit JVM allows for and requires a bigger heap
+  JVM_HEAP_LIMIT_64="1600"
+  STACK_SIZE_32=768
+  STACK_SIZE_64=1536
+  JVM_HEAP_LIMIT_GLOBAL=`expr $MEMORY_SIZE / 2`
+  if test "$JVM_HEAP_LIMIT_GLOBAL" -lt "$JVM_HEAP_LIMIT_32"; then
+    JVM_HEAP_LIMIT_32=$JVM_HEAP_LIMIT_GLOBAL
+  fi
+  if test "$JVM_HEAP_LIMIT_GLOBAL" -lt "$JVM_HEAP_LIMIT_64"; then
+    JVM_HEAP_LIMIT_64=$JVM_HEAP_LIMIT_GLOBAL
+  fi
+  if test "$JVM_HEAP_LIMIT_GLOBAL" -lt "512"; then
+    JVM_HEAP_LIMIT_32=512
+    JVM_HEAP_LIMIT_64=512
+  fi
+
+  if test "x$BOOT_JDK_BITS" = "x32"; then
+    STACK_SIZE=$STACK_SIZE_32
+    JVM_MAX_HEAP=$JVM_HEAP_LIMIT_32
+  else
+    STACK_SIZE=$STACK_SIZE_64
+    JVM_MAX_HEAP=$JVM_HEAP_LIMIT_64
+  fi
+  ADD_JVM_ARG_IF_OK([-Xmx${JVM_MAX_HEAP}M],boot_jdk_jvmargs_big,[$JAVA])
+  ADD_JVM_ARG_IF_OK([-XX:ThreadStackSize=$STACK_SIZE],boot_jdk_jvmargs_big,[$JAVA])
+
+  AC_MSG_RESULT([$boot_jdk_jvmargs_big])
+
+  JAVA_FLAGS_BIG=$boot_jdk_jvmargs_big
+  AC_SUBST(JAVA_FLAGS_BIG)
+
+  if test "x$OPENJDK_TARGET_CPU_BITS" = "x32"; then
+    BOOTCYCLE_MAX_HEAP=$JVM_HEAP_LIMIT_32
+    BOOTCYCLE_STACK_SIZE=$STACK_SIZE_32
+  else
+    BOOTCYCLE_MAX_HEAP=$JVM_HEAP_LIMIT_64
+    BOOTCYCLE_STACK_SIZE=$STACK_SIZE_64
+  fi
+  BOOTCYCLE_JVM_ARGS_BIG="$BOOTCYCLE_JVM_ARGS_BIG -Xmx${BOOTCYCLE_MAX_HEAP}M"
+  BOOTCYCLE_JVM_ARGS_BIG="$BOOTCYCLE_JVM_ARGS_BIG -XX:ThreadStackSize=$BOOTCYCLE_STACK_SIZE"
+  AC_MSG_CHECKING([flags for bootcycle boot jdk java command for big workloads])
+  AC_MSG_RESULT([$BOOTCYCLE_JVM_ARGS_BIG])
+  AC_SUBST(BOOTCYCLE_JVM_ARGS_BIG)
+
+  # By default, the main javac compilations use big
+  JAVA_FLAGS_JAVAC="$JAVA_FLAGS_BIG"
+  AC_SUBST(JAVA_FLAGS_JAVAC)
+
+  AC_MSG_CHECKING([flags for boot jdk java command for small workloads])
+
+  # Use serial gc for small short lived tools if possible
+  ADD_JVM_ARG_IF_OK([-XX:+UseSerialGC],boot_jdk_jvmargs_small,[$JAVA])
+  ADD_JVM_ARG_IF_OK([-Xms32M],boot_jdk_jvmargs_small,[$JAVA])
+  ADD_JVM_ARG_IF_OK([-Xmx512M],boot_jdk_jvmargs_small,[$JAVA])
+  ADD_JVM_ARG_IF_OK([-XX:TieredStopAtLevel=1],boot_jdk_jvmargs_small,[$JAVA])
+
+  AC_MSG_RESULT([$boot_jdk_jvmargs_small])
+
+  JAVA_FLAGS_SMALL=$boot_jdk_jvmargs_small
+  AC_SUBST(JAVA_FLAGS_SMALL)
+
+  JAVA_TOOL_FLAGS_SMALL=""
+  for f in $JAVA_FLAGS_SMALL; do
+    JAVA_TOOL_FLAGS_SMALL="$JAVA_TOOL_FLAGS_SMALL -J$f"
+  done
+  AC_SUBST(JAVA_TOOL_FLAGS_SMALL)
+])
+
+# BUILD_JDK: the location of the latest JDK that can run
+#   on the host system and supports the target class file version
+#   generated in this JDK build.  This variable should only be
+#   used after the launchers are built.
+#
+
+# Execute the check given as argument, and verify the result.
+# If the JDK was previously found, do nothing.
+# $1 A command line (typically autoconf macro) to execute
+AC_DEFUN([BOOTJDK_CHECK_BUILD_JDK],
+[
+  if test "x$BUILD_JDK_FOUND" = xno; then
+    # Execute the test
+    $1
+
+    # If previous step claimed to have found a JDK, check it to see if it seems to be valid.
+    if test "x$BUILD_JDK_FOUND" = xmaybe; then
+      # Do we have a bin/java?
+      if test ! -x "$BUILD_JDK/bin/java"; then
+        AC_MSG_NOTICE([Potential Build JDK found at $BUILD_JDK did not contain bin/java; ignoring])
+        BUILD_JDK_FOUND=no
+      elif test ! -x "$BUILD_JDK/bin/jlink"; then
+        AC_MSG_NOTICE([Potential Build JDK found at $BUILD_JDK did not contain bin/jlink; ignoring])
+        BUILD_JDK_FOUND=no
+      elif test ! -x "$BUILD_JDK/bin/jmod"; then
+        AC_MSG_NOTICE([Potential Build JDK found at $BUILD_JDK did not contain bin/jmod; ignoring])
+        BUILD_JDK_FOUND=no
+      elif test ! -x "$BUILD_JDK/bin/javac"; then
+        # Do we have a bin/javac?
+        AC_MSG_NOTICE([Potential Build JDK found at $BUILD_JDK did not contain bin/javac; ignoring])
+        AC_MSG_NOTICE([(This might be a JRE instead of an JDK)])
+        BUILD_JDK_FOUND=no
+      else
+        # Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
+        BUILD_JDK_VERSION=`"$BUILD_JDK/bin/java" -version 2>&1 | $HEAD -n 1`
+
+        # Extra M4 quote needed to protect [] in grep expression.
+        [FOUND_CORRECT_VERSION=`echo $BUILD_JDK_VERSION | $EGREP '\"9([\.+-].*)?\"'`]
+        if test "x$FOUND_CORRECT_VERSION" = x; then
+          AC_MSG_NOTICE([Potential Build JDK found at $BUILD_JDK is incorrect JDK version ($BUILD_JDK_VERSION); ignoring])
+          AC_MSG_NOTICE([(Your Build JDK must be version 9)])
+          BUILD_JDK_FOUND=no
+        else
+          # We're done!
+          BUILD_JDK_FOUND=yes
+          BASIC_FIXUP_PATH(BUILD_JDK)
+          AC_MSG_CHECKING([for Build JDK])
+          AC_MSG_RESULT([$BUILD_JDK])
+          AC_MSG_CHECKING([Build JDK version])
+          BUILD_JDK_VERSION=`"$BUILD_JDK/bin/java" -version 2>&1 | $TR '\n\r' '  '`
+          AC_MSG_RESULT([$BUILD_JDK_VERSION])
+        fi # end check jdk version
+      fi # end check java
+    fi # end check build jdk found
+  fi
+])
+
+# By default the BUILD_JDK is the JDK_OUTPUTDIR.  If the target architecture
+# is different than the host system doing the build (e.g. cross-compilation),
+# a special BUILD_JDK is built as part of the build process.  An external
+# prebuilt BUILD_JDK can also be supplied.
+AC_DEFUN([BOOTJDK_SETUP_BUILD_JDK],
+[
+  AC_ARG_WITH(build-jdk, [AS_HELP_STRING([--with-build-jdk],
+      [path to JDK of same version as is being built@<:@the newly built JDK@:>@])])
+
+  CREATE_BUILDJDK=false
+  EXTERNAL_BUILDJDK=false
+  BUILD_JDK_FOUND="no"
+  if test "x$with_build_jdk" != "x"; then
+    BOOTJDK_CHECK_BUILD_JDK([
+       if test "x$with_build_jdk" != x; then
+         BUILD_JDK=$with_build_jdk
+         BUILD_JDK_FOUND=maybe
+         AC_MSG_NOTICE([Found potential Build JDK using configure arguments])
+       fi])
+    EXTERNAL_BUILDJDK=true
+  else
+    if test "x$COMPILE_TYPE" = "xcross"; then
+      BUILD_JDK="\$(BUILDJDK_OUTPUTDIR)/jdk"
+      BUILD_JDK_FOUND=yes
+      CREATE_BUILDJDK=true
+      AC_MSG_CHECKING([for Build JDK])
+      AC_MSG_RESULT([yes, will build it for the host platform])
+    else
+      BUILD_JDK="\$(JDK_OUTPUTDIR)"
+      BUILD_JDK_FOUND=yes
+      AC_MSG_CHECKING([for Build JDK])
+      AC_MSG_RESULT([yes, will use output dir])
+    fi
+  fi
+
+  JMOD="$BUILD_JDK/bin/jmod"
+  JLINK="$BUILD_JDK/bin/jlink"
+  AC_SUBST(JMOD)
+  AC_SUBST(JLINK)
+
+  if test "x$BUILD_JDK_FOUND" != "xyes"; then
+    AC_MSG_CHECKING([for Build JDK])
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([Could not find a suitable Build JDK])
+  fi
+
+  AC_SUBST(CREATE_BUILDJDK)
+  AC_SUBST(BUILD_JDK)
+  AC_SUBST(EXTERNAL_BUILDJDK)
+])