Implement javax.tools.ToolProvider using ecj. Cleanup and make more use of Classpath logging mechanism.

Signed-off-by: Andrew John Hughes <gnu_andrew@member.fsf.org>

1 files changed, 191 insertions, 0 deletions

diff --git a/javax/tools/ToolProvider.java b/javax/tools/ToolProvider.java
new file mode 100644
index 000000000..3d16238b6
--- /dev/null
+++ b/javax/tools/ToolProvider.java
@@ -0,0 +1,191 @@
+/* ToolProvider.java -- Provides methods for obtaining tool implementations.
+   Copyright (C) 2013  Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package javax.tools;
+
+import gnu.classpath.Configuration;
+
+import static gnu.classpath.debug.Component.SERVICE_LOADING_VERBOSE;
+import static gnu.classpath.debug.Component.SERVICE_LOADING_WARNING;
+import static gnu.classpath.debug.SystemLogger.SYSTEM;
+
+import gnu.classpath.debug.Component;
+
+import java.io.File;
+
+import java.lang.reflect.InvocationTargetException;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+
+/**
+ * Provides methods for obtaining tool implementations.
+ * This complements the functionality provided by
+ * {@link ServiceLoader}.
+ *
+ * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
+ * @since 1.6
+ */
+public class ToolProvider
+{
+
+  /** The system compiler if available. */
+  private static JavaCompiler compiler;
+
+  /** The class that implements the system compiler. */
+  private static final String COMPILER_CLASS =
+    "org.eclipse.jdt.internal.compiler.tool.EclipseCompiler";
+
+  /**
+   * Returns the system Java compiler.  This does not take
+   * account of compilers provided through the service
+   * loader functionality.
+   *
+   * @return the system compiler or {@code null} if one is not
+   *         provided.
+   */
+  public static synchronized JavaCompiler getSystemJavaCompiler()
+  {
+    if (compiler == null)
+    {
+      Class<?> compilerClass = getCompilerClass();
+      if (compilerClass != null)
+	try
+	{
+	  compiler = (JavaCompiler)
+	    compilerClass.getConstructor().newInstance();
+	}
+	catch (NoSuchMethodException e)
+	{
+	  log(SERVICE_LOADING_WARNING, e,
+	      "Couldn't find compiler constructor");
+	}
+	catch (InstantiationException e)
+	{
+	  log(SERVICE_LOADING_WARNING, e,
+	      "Couldn't run compiler constructor");
+	}
+	catch (IllegalAccessException e)
+	{
+	  log(SERVICE_LOADING_WARNING, e,
+	      "Couldn't access compiler constructor");
+	}
+	catch (InvocationTargetException e)
+	{
+	  log(SERVICE_LOADING_WARNING, e,
+	      "Exception running compiler constructor");
+	}
+    }
+    return compiler;
+  }
+
+  /**
+   * Returns the class loader used to load system tools.
+   *
+   * @return the tool class loader or {@code null} if no
+   *         tools are provided.
+   */
+  public static synchronized ClassLoader getSystemToolClassLoader()
+  {
+    if (compiler != null)
+      return compiler.getClass().getClassLoader();
+    return null;
+  }
+
+  private static Class<?> getCompilerClass()
+  {
+    Class<?> compilerClass = null;
+    try
+    {
+      compilerClass = Class.forName(COMPILER_CLASS);
+    }
+    catch (ClassNotFoundException ex)
+    {
+      log(SERVICE_LOADING_VERBOSE, ex,
+	  "Couldn''t find {0} on classpath",
+	  COMPILER_CLASS);
+
+      File jar = new File(Configuration.ECJ_JAR);
+      if (jar.exists() && jar.canRead())
+	{
+	  try
+	    {
+	      ClassLoader loader =
+		new URLClassLoader(new URL[] { jar.toURL() });
+	      compilerClass = loader.loadClass(COMPILER_CLASS);
+	    }
+	  catch (MalformedURLException e)
+	  {
+	    log(SERVICE_LOADING_WARNING, e,
+		"Bad ecj JAR URL: {0}", jar);
+	  }
+	  catch (ClassNotFoundException e) 
+	  {
+	    log(SERVICE_LOADING_VERBOSE, e,
+		"Couldn''t find {0} in ecj jar", COMPILER_CLASS);
+	  }
+	}
+    }
+    return compilerClass;
+  }
+  
+  /**
+   * Passes a log message to the <code>java.util.logging</code>
+   * framework. This call returns very quickly if no log message will
+   * be produced, so there is not much overhead in the standard case.
+   *
+   * @param level the severity of the message, for instance {@link
+   * Component#SERVICE_LOGGING_WARNING}.
+   * @param t a Throwable that is associated with the log record, or
+   * <code>null</code> if the log message is not associated with a
+   * Throwable.
+   * @param msg the log message, for instance <code>&#x201c;Could not
+   * load {0}.&#x201d;</code> 
+   * @param params the parameter(s) for the log message, or
+   * <code>null</code> if <code>msg</code> does not specify any
+   * parameters. If <code>param</code> is not an array, an array with
+   * <code>param</code> as its single element gets passed to the
+   * logging framework.
+   */
+  private static void log(Component level, Throwable t, String msg, Object... params)
+  {
+    SYSTEM.logp(level, ToolProvider.class.getName(), "getSystemJavaCompiler",
+		t, msg, params);
+  }
+
+}