[GR-17359] Implement loading java packages without java.

PullRequest: graalpython/603

Author: timfel

CHANGELOG.md

@@ -3,6 +3,19 @@
 This changelog summarizes major changes between GraalVM versions of the Python
 language runtime. The main focus is on user-observable behavior of the engine.
 
+## Version 19.3.0
+
+* Implement `charmap_build` function
+* Implement `hexversion` in sys module
+* Implement `_lzma` module
+* Fix printing of Pandas data frames
+* Fix a bug in `bytes.startswith` for tuple arguments
+* Fix destructuring assignments of arbitrary iterators
+* Fix `dict.__contains__` for dictionaries with only `str` keys for subclasses of `str`
+* Support NumPy 1.16.4 and Pandas 0.25.0
+* Support importing Java classes using normal Python import syntax when the package is known
+* Improve performance across many Python benchmarks
+
 ## Version 19.2.0
 
 * Implement PyStructSequence_* C API functions

graalpython/com.oracle.graal.python.test/src/tests/test_interop.py

@@ -340,6 +340,13 @@ def test_java_imports():
 
             assert java.util.ArrayList == ArrayList
 
+            import sun
+            assert type(sun.misc) is type(java)
+
+            import sun.misc.Signal
+            assert sun.misc.Signal is not None
+
+
     def test_foreign_object_does_not_leak_Javas_toString():
         try:
             from java.util import ArrayList

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java

@@ -176,6 +176,7 @@ public void postInitialize(PythonCore core) {
         }
 
         sys.setAttribute("executable", PythonOptions.getOption(context, PythonOptions.Executable));
+        sys.setAttribute("graal_python_host_import_enabled", context.getEnv().isHostLookupAllowed());
         sys.setAttribute("graal_python_home", context.getLanguage().getHome());
         sys.setAttribute("graal_python_core_home", context.getCoreHome());
         sys.setAttribute("graal_python_stdlib_home", context.getStdlibHome());

graalpython/lib-graalpython/java.py

@@ -41,30 +41,41 @@
 
 
 class JavaPackageLoader:
+    @staticmethod
+    def is_java_package(name):
+        try:
+            package = type("java.lang.Package")
+            return any(p.getName().startswith(name) for p in package.getPackages())
+        except KeyError:
+            if sys.flags.verbose:
+                from _warnings import _warn
+                _warn("Host lookup allowed, but java.lang.Package not available. Importing from Java cannot work.")
+            return False
+
     @staticmethod
     def _make_getattr(modname):
-        if modname.startswith("java."):
-            modname_wo = modname[len("java."):] + "."
-        else:
-            modname_wo = None
         modname = modname + "."
         def __getattr__(key, default=None):
-            try:
-                return type(modname + key)
-            except KeyError:
-                pass
-            if modname_wo:
-                try:
-                    return type(modname_wo + key)
-                except KeyError:
-                    pass
+            if sys.graal_python_host_import_enabled:
+                loadname = modname + key
+                if JavaPackageLoader.is_java_package(loadname):
+                    return JavaPackageLoader._create_module(loadname)
+                else:
+                    try:
+                        return type(modname + key)
+                    except KeyError:
+                        pass
             raise AttributeError(key)
         return __getattr__
 
     @staticmethod
     def create_module(spec):
-        newmod = _frozen_importlib._new_module(spec.name)
-        newmod.__getattr__ = JavaPackageLoader._make_getattr(spec.name)
+        return JavaPackageLoader._create_module(spec.name)
+
+    @staticmethod
+    def _create_module(name):
+        newmod = _frozen_importlib._new_module(name)
+        newmod.__getattr__ = JavaPackageLoader._make_getattr(name)
         newmod.__path__ = __path__
         return newmod
 
@@ -80,23 +91,22 @@ def create_module(spec):
 
     @staticmethod
     def exec_module(module):
-        try:
-            sys.modules[module.__name__] = type(module.__name__)
-        except KeyError:
-            if module.__name__.startswith("java."):
-                sys.modules[module.__name__] = type(module.__name__[len("java."):])
-            else:
-                raise
+        sys.modules[module.__name__] = type(module.__name__)
 
 
 class JavaImportFinder:
     @staticmethod
     def find_spec(fullname, path, target=None):
-        if path and path == __path__:
-            if fullname.rpartition('.')[2].islower():
+        if sys.graal_python_host_import_enabled:
+            if JavaPackageLoader.is_java_package(fullname):
                 return _frozen_importlib.ModuleSpec(fullname, JavaPackageLoader, is_package=True)
             else:
-                return _frozen_importlib.ModuleSpec(fullname, JavaTypeLoader, is_package=False)
+                try:
+                    type(fullname)
+                    return _frozen_importlib.ModuleSpec(fullname, JavaTypeLoader, is_package=False)
+                except KeyError:
+                    pass
 
 
 sys.meta_path.append(JavaImportFinder)
+__getattr__ = JavaPackageLoader._make_getattr("java")

mx.graalpython/mx_graalpython.py

@@ -270,7 +270,7 @@ def python_gvm(args=None):
 
 def python_svm(args=None):
     "Build and run the native graalpython image"
-    with set_env(FORCE_BASH_LAUNCHERS="lli,native-image", DISABLE_LIBPOLYGLOT="true", DISABLE_POLYGLOT="true"):
+    with set_env(FORCE_BASH_LAUNCHERS="lli,native-image,gu,graalvm-native-clang,graalvm-native-clang++", DISABLE_LIBPOLYGLOT="true", DISABLE_POLYGLOT="true"):
         return _python_graalvm_launcher(args or [])