8162712: StandardJavaFileManager.getModuleLocation() can't find a module

Reviewed-by: jlahoda

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/Locations.java

@@ -890,6 +890,8 @@ public class Locations {
      * like UPGRADE_MODULE_PATH and MODULE_PATH.
      */
     private class ModulePathLocationHandler extends SimpleLocationHandler {
+        private Map<String, ModuleLocationHandler> pathModules;
+
         ModulePathLocationHandler(Location location, Option... options) {
             super(location, options);
         }
@@ -903,6 +905,12 @@ public class Locations {
             return true;
         }
 
+        @Override
+        public Location getLocationForModule(String moduleName) {
+            initPathModules();
+            return pathModules.get(moduleName);
+        }
+
         @Override
         Iterable<Set<Location>> listLocationsForModules() {
             if (searchPath == null)
@@ -921,6 +929,23 @@ public class Locations {
             super.setPaths(paths);
         }
 
+        private void initPathModules() {
+            if (pathModules != null) {
+                return;
+            }
+
+            pathModules = new LinkedHashMap<>();
+
+            for (Set<Location> set : listLocationsForModules()) {
+                for (Location locn : set) {
+                    if (locn instanceof ModuleLocationHandler) {
+                        ModuleLocationHandler h = (ModuleLocationHandler) locn;
+                        pathModules.put(h.moduleName, h);
+                    }
+                }
+            }
+        }
+
         private void checkValidModulePathEntry(Path p) {
             if (Files.isDirectory(p)) {
                 // either an exploded module or a directory of modules
@@ -1158,7 +1183,6 @@ public class Locations {
         private Map<String, Location> moduleLocations;
         private Map<Path, Location> pathLocations;
 
-
         ModuleSourcePathLocationHandler() {
             super(StandardLocation.MODULE_SOURCE_PATH,
                     Option.MODULE_SOURCE_PATH);

langtools/test/tools/javac/modules/GetLocationForModuleTest.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8162712
+ * @summary StandardJavaFileManager.getModuleLocation() can't find a module
+ * @library /tools/lib
+ * @modules
+ *      jdk.compiler/com.sun.tools.javac.api
+ *      jdk.compiler/com.sun.tools.javac.main
+ * @build toolbox.JavacTask toolbox.ToolBox
+ * @run main GetLocationForModuleTest
+ */
+
+import java.io.IOException;
+import java.nio.file.*;
+import java.util.*;
+import javax.tools.*;
+import toolbox.JavacTask;
+import toolbox.ToolBox;
+
+public class GetLocationForModuleTest extends ModuleTestBase {
+    public static void main(String... args) throws Exception {
+        new GetLocationForModuleTest().run(Paths.get("."));
+    }
+
+    public void run(Path base) throws Exception {
+        // Set up some trivial modules
+        Path moduleSrc = base.resolve("module-src");
+        Path m1 = moduleSrc.resolve("m1");
+        tb.writeJavaFiles(m1, "module m1 { }");
+        Path m2 = moduleSrc.resolve("m2");
+        tb.writeJavaFiles(m2, "module m2 { }");
+
+        Path modulePath = base.resolve("module-path");
+        Files.createDirectories(modulePath);
+        new JavacTask(tb)
+                .options("--module-source-path", moduleSrc.toString())
+                .outdir(modulePath)
+                .files(findJavaFiles(moduleSrc))
+                .run()
+                .writeAll();
+
+        // Init file manager
+        StandardJavaFileManager fm =
+                ToolProvider.getSystemJavaCompiler().getStandardFileManager(null, null, null);
+        fm.setLocationFromPaths(StandardLocation.MODULE_PATH, Arrays.asList(modulePath));
+
+        // Test
+        test(fm, StandardLocation.SYSTEM_MODULES, "java.base", "java.compiler");
+        test(fm, StandardLocation.MODULE_PATH, "m1", "m2");
+    }
+
+    void test(JavaFileManager fm, JavaFileManager.Location locn, String... mods) throws IOException {
+        for (String mod : mods) {
+            JavaFileManager.Location modLocn = fm.getLocationForModule(locn, mod);
+            if (modLocn == null) {
+                error(locn.getName() + ": can't find " + mod);
+            } else {
+                System.err.println(locn.getName() + ": found " + mod + ": " + modLocn.getName());
+            }
+        }
+    }
+}
+