--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/main/Main.java	Wed May 25 11:33:56 2016 -0400
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/main/Main.java	Thu May 26 10:45:13 2016 -0700
@@ -174,6 +174,17 @@
             return Result.CMDERR;
         }
 
+        // prefix argv with contents of _JAVAC_OPTIONS if set
+        String envOpt = System.getenv("_JAVAC_OPTIONS");
+        if (envOpt != null && !envOpt.trim().isEmpty()) {
+            String[] envv = envOpt.split("\\s+");
+            String[] result = new String[envv.length + argv.length];
+            System.arraycopy(envv, 0, result, 0, envv.length);
+            System.arraycopy(argv, 0, result, envv.length, argv.length);
+            argv = result;
+        }
+
+        // expand @-files
         try {
             argv = CommandLine.parse(argv);
         } catch (FileNotFoundException | NoSuchFileException e) {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/modules/EnvVarTest.java	Thu May 26 10:45:13 2016 -0700
@@ -0,0 +1,94 @@
+/*
+ * 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 8156962
+ * @summary Tests use of _JAVAC_OPTIONS env variable
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.main
+ * @build toolbox.ToolBox toolbox.JavacTask ModuleTestBase
+ * @run main EnvVarTest
+ */
+
+import java.nio.file.Path;
+
+import toolbox.JavacTask;
+import toolbox.Task.Expect;
+import toolbox.Task.Mode;
+
+public class EnvVarTest extends ModuleTestBase {
+
+    public static void main(String... args) throws Exception {
+        new EnvVarTest().runTests();
+    }
+
+    @Test
+    public void testAddExports(Path base) throws Exception {
+        Path src = base.resolve("src");
+        // the package in the following call should be one that is not
+        // available by default, including via @modules
+        tb.writeJavaFiles(src,
+            "package p; public class C { com.sun.tools.javac.jvm.Target t; }");
+        Path classes = base.resolve("classes");
+        tb.createDirectories(classes);
+
+        tb.out.println("test that compilation fails if addExports is not provided");
+        new JavacTask(tb)
+                .outdir(classes)
+                .files(findJavaFiles(src))
+                .run(Expect.FAIL)
+                .writeAll();
+
+        tb.out.println("test that addExports can be given to javac");
+        new JavacTask(tb)
+                .options("-XaddExports:jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED")
+                .outdir(classes)
+                .files(findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll();
+
+        tb.out.println("test that addExports can be provided with env variable");
+        new JavacTask(tb, Mode.EXEC)
+                .envVar("_JAVAC_OPTIONS", "-XaddExports:jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED")
+                .outdir(classes)
+                .files(findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll();
+
+        tb.out.println("test that addExports can be provided with env variable using @file");
+        Path atFile = src.resolve("at-file.txt");
+        tb.writeFile(atFile,
+                "-XaddExports:jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED");
+
+        new JavacTask(tb, Mode.EXEC)
+                .envVar("_JAVAC_OPTIONS", "@" + atFile)
+                .outdir(classes)
+                .files(findJavaFiles(src))
+                .run(Expect.SUCCESS)
+                .writeAll();
+    }
+
+}
+