Update Java support for more versions

* on Windows, detect more possible JDK locations.
* On all platforms, more Java versions (up to 17.0 now).
* Add some docu on version selection and on JavaH tool in light of javah
  command dropped since 10.0.
* Try to be better about preserving user's passed-in JAVA* consvars.

Signed-off-by: Mats Wichmann <mats@linux.com>

1 files changed, 113 insertions, 45 deletions

diff --git a/SCons/Tool/JavaCommon.py b/SCons/Tool/JavaCommon.py
index d869b38..dac7d50 100644
--- a/SCons/Tool/JavaCommon.py
+++ b/SCons/Tool/JavaCommon.py
@@ -1,11 +1,6 @@
-"""SCons.Tool.JavaCommon
-
-Stuff for processing Java.
-
-"""
-
+# MIT License
 #
-# __COPYRIGHT__
+# Copyright The SCons Foundation
 #
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
@@ -25,16 +20,16 @@ Stuff for processing Java.
 # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-#
 
-__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+"""Common routines for processing Java. """
 
 import os
-import os.path
 import re
 import glob
+from pathlib import Path
+from typing import List
 
-java_parsing = 1
+java_parsing = True
 
 default_java_version = '1.4'
 
@@ -43,13 +38,18 @@ default_java_version = '1.4'
 scopeStateVersions = ('1.8',)
 
 # Glob patterns for use in finding where the JDK is.
-# These are pairs, *dir_glob used in the general case,
-# *version_dir_glob if matching only a specific version.
-# For now only used for Windows.
-java_win32_dir_glob = 'C:/Program Files*/Java/jdk*/bin'
+#
+# These are pairs, (*dir_glob, *version_dir_glob) depending on whether
+# a JDK version was requested or not.
+# For now only used for Windows, which doesn't install JDK in a
+# path that would be in env['ENV']['PATH'].  The specific tool will
+# add the discovered path to this.  Since Oracle changed the rules,
+# there are many possible vendors, we can't guess them all, but take a shot.
+java_win32_dir_glob = 'C:/Program Files*/*/*jdk*/bin'
+
 # On windows, since Java 9, there is a dash between 'jdk' and the version
 # string that wasn't there before. this glob should catch either way.
-java_win32_version_dir_glob = 'C:/Program Files*/Java/jdk*%s*/bin'
+java_win32_version_dir_glob = 'C:/Program Files*/*/*jdk*%s*/bin'
 
 # Glob patterns for use in finding where the JDK headers are.
 # These are pairs, *dir_glob used in the general case,
@@ -98,9 +98,27 @@ if java_parsing:
         interfaces, and anonymous inner classes."""
 
         def __init__(self, version=default_java_version):
-
-            if version not in ('1.1', '1.2', '1.3', '1.4', '1.5', '1.6', '1.7',
-                               '1.8', '5', '6', '9.0', '10.0', '11.0', '12.0'):
+            if version not in (
+                '1.1',
+                '1.2',
+                '1.3',
+                '1.4',
+                '1.5',
+                '1.6',
+                '1.7',
+                '1.8',
+                '5',
+                '6',
+                '9.0',
+                '10.0',
+                '11.0',
+                '12.0',
+                '13.0',
+                '14.0',
+                '15.0',
+                '16.0',
+                '17.0',
+            ):
                 msg = "Java version %s not supported" % version
                 raise NotImplementedError(msg)
 
@@ -207,7 +225,24 @@ if java_parsing:
             if self.version in ('1.1', '1.2', '1.3', '1.4'):
                 clazz = self.listClasses[0]
                 self.listOutputs.append('%s$%d' % (clazz, self.nextAnon))
-            elif self.version in ('1.5', '1.6', '1.7', '1.8', '5', '6', '9.0', '10.0', '11.0', '12.0'):
+            # TODO: shouldn't need to repeat versions here and in OuterState
+            elif self.version in (
+                '1.5',
+                '1.6',
+                '1.7',
+                '1.8',
+                '5',
+                '6',
+                '9.0',
+                '10.0',
+                '11.0',
+                '12.0',
+                '13.0',
+                '14.0',
+                '15.0',
+                '16.0',
+                '17.0',
+            ):
                 self.stackAnonClassBrackets.append(self.brackets)
                 className = []
                 className.extend(self.listClasses)
@@ -443,49 +478,82 @@ else:
         return os.path.split(fn)
 
 
-def get_java_install_dirs(platform, version=None):
-    """
-    Find the java jdk installation directories.
+def get_java_install_dirs(platform, version=None) -> List[str]:
+    """ Find possible java jdk installation directories.
+
+    Returns a list for use as `default_paths` when looking up actual
+    java binaries with :meth:`SCons.Tool.find_program_path`.
+    The paths are sorted by version, latest first.
 
-    This list is intended to supply as "default paths" for use when looking
-    up actual java binaries.
+    Args:
+        platform: selector for search algorithm.
+        version: if not None, restrict the search to this version.
 
-    :param platform: selector for search algorithm.
-    :param version: If specified, only look for java sdk's of this version
-    :return: list of default paths for java.
+    Returns:
+        list of default paths for jdk.
     """
 
-    paths = []
     if platform == 'win32':
+        paths = []
         if version:
             paths = glob.glob(java_win32_version_dir_glob % version)
         else:
             paths = glob.glob(java_win32_dir_glob)
-    else:
-        # other platforms, do nothing for now
-        pass
 
-    return sorted(paths)
+        def win32getvnum(java):
+            """ Generates a sort key for win32 jdk versions.
 
+            We'll have gotten a path like ...something/*jdk*/bin because
+            that is the pattern we glob for. To generate the sort key,
+            extracts the next-to-last component, then trims it further if
+            it had a complex name, like 'java-1.8.0-openjdk-1.8.0.312-1',
+            to try and put it on a common footing with the more common style,
+            which looks like 'jdk-11.0.2'. 
+
+            This is certainly fragile, and if someone has a 9.0 it won't
+            sort right since this will still be alphabetic, BUT 9.0 was
+            not an LTS release and is 30 mos out of support as this note
+            is written so just assume it will be okay.
+            """
+            d = Path(java).parts[-2]
+            if not d.startswith('jdk'):
+                d = 'jdk' + d.rsplit('jdk', 1)[-1]
+            return d
+
+        return sorted(paths, key=win32getvnum, reverse=True)
+
+    # other platforms, do nothing for now: we expect the standard
+    # paths to be enough to find a jdk (e.g. use alternatives system)
+    return []
 
-def get_java_include_paths(env, javac, version):
-    """
-    Find java include paths for JNI building.
 
-    :param env: construction environment, used to extract platform.
-    :param javac: path to detected javac.
-    :return: list of paths.
+def get_java_include_paths(env, javac, version) -> List[str]:
+    """Find java include paths for JNI building.
+
+    Cannot be called in isolation - `javac` refers to an already detected
+    compiler. Normally would would call :func:`get_java_install_dirs` first
+    and then do lookups on the paths it returns before calling us.
+
+    Args:
+        env: construction environment, used to extract platform.
+        javac: path to detected javac.
+        version: if not None, restrict the search to this version.
+
+    Returns:
+        list of include directory paths.
     """
 
-    paths = []
     if not javac:
-        # there are no paths if we've not detected javac.
-        pass
-    elif env['PLATFORM'] == 'win32':
-        # on Windows, we have the right path to javac, so look locally
+        return []
+
+    # on Windows, we have a path to the actual javac, so look locally
+    if env['PLATFORM'] == 'win32':
         javac_bin_dir = os.path.dirname(javac)
         java_inc_dir = os.path.normpath(os.path.join(javac_bin_dir, '..', 'include'))
         paths = [java_inc_dir, os.path.join(java_inc_dir, 'win32')]
+
+    # for the others, we probably found something which isn't in the JDK dir,
+    # so use the predefined patterns to glob for an include directory.
     elif env['PLATFORM'] == 'darwin':
         if not version:
             paths = [java_macos_include_dir_glob]
@@ -500,10 +568,10 @@ def get_java_include_paths(env, javac, version):
             for p in java_linux_version_include_dirs_glob:
                 base_paths.extend(glob.glob(p % version))
 
+        paths = []
         for p in base_paths:
             paths.extend([p, os.path.join(p, 'linux')])
 
-    # print("PATHS:%s"%paths)
     return paths
 
 # Local Variables: