Making compiler exit codes type safe. Fixes the problem with wrong command-line argument usage being missed by the IDE

compiler/cli/src/org/jetbrains/jet/cli/KotlinCompiler.java

@@ -23,6 +23,8 @@ import org.jetbrains.jet.compiler.MessageRenderer;
 
 import java.io.PrintStream;
 
+import static org.jetbrains.jet.cli.KotlinCompiler.ExitCode.*;
+
 /**
  * @author yole
  * @author alex.tkachman
@@ -30,6 +32,22 @@ import java.io.PrintStream;
 @SuppressWarnings("UseOfSystemOutOrSystemErr")
 public class KotlinCompiler {
 
+    public enum ExitCode {
+        OK(0),
+        COMPILATION_ERROR(1),
+        INTERNAL_ERROR(2);
+
+        private final int code;
+
+        private ExitCode(int code) {
+            this.code = code;
+        }
+
+        public int getCode() {
+            return code;
+        }
+    }
+
     public static void main(String... args) {
         doMain(new KotlinCompiler(), args);
     }
@@ -39,25 +57,25 @@ public class KotlinCompiler {
      */
     public static void doMain(KotlinCompiler compiler, String[] args) {
         try {
-            int rc = compiler.exec(args);
-            if (rc != 0) {
+            ExitCode rc = compiler.exec(args);
+            if (rc != OK) {
                 System.err.println("exec() finished with " + rc + " return code");
-                System.exit(rc);
+                System.exit(rc.getCode());
             }
         } catch (CompileEnvironmentException e) {
             System.err.println(e.getMessage());
-            System.exit(1);
+            System.exit(INTERNAL_ERROR.getCode());
         }
     }
 
-    public int exec(String... args) {
+    public ExitCode exec(String... args) {
         return exec(System.out, args);
     }
 
-    public int exec(PrintStream errStream, String... args) {
+    public ExitCode exec(PrintStream errStream, String... args) {
         CompilerArguments arguments = createArguments();
         if (!parseArguments(errStream, arguments, args)) {
-            return 1;
+            return INTERNAL_ERROR;
         }
         return exec(errStream, arguments);
     }
@@ -65,10 +83,10 @@ public class KotlinCompiler {
     /**
      * Executes the compiler on the parsed arguments
      */
-    public int exec(PrintStream errStream, CompilerArguments arguments) {
+    public ExitCode exec(PrintStream errStream, CompilerArguments arguments) {
         if (arguments.help) {
             usage(errStream);
-            return 0;
+            return OK;
         }
         System.setProperty("java.awt.headless", "true");
 
@@ -84,11 +102,11 @@ public class KotlinCompiler {
             else {
                 noErrors = environment.compileBunchOfSources(arguments.src, arguments.jar, arguments.outputDir, arguments.includeRuntime);
             }
-            return noErrors ? 0 : 1;
+            return noErrors ? OK : COMPILATION_ERROR;
         }
         catch (Throwable t) {
             errStream.println(messageRenderer.renderException(t));
-            return 1;
+            return INTERNAL_ERROR;
         }
         finally {
             environment.dispose();
@@ -104,7 +122,7 @@ public class KotlinCompiler {
             return true;
         }
         catch (IllegalArgumentException e) {
-            usage(System.err);
+            usage(errStream);
         }
         catch (Throwable t) {
             // Always use tags

compiler/tests/org/jetbrains/jet/compiler/CompileEnvironmentTest.java

@@ -55,10 +55,10 @@ public class CompileEnvironmentTest extends TestCase {
         try {
             File stdlib = ForTestCompileStdlib.stdlibJarForTests();
             File resultJar = new File(tempDir, "result.jar");
-            int rv = new KotlinCompiler().exec("-module", JetParsingTest.getTestDataDir() + "/compiler/smoke/Smoke.kts",
-                                "-jar", resultJar.getAbsolutePath(),
-                                "-stdlib", stdlib.getAbsolutePath());
-            Assert.assertEquals("compilation completed with non-zero code", 0, rv);
+            KotlinCompiler.ExitCode rv = new KotlinCompiler().exec("-module", JetParsingTest.getTestDataDir() + "/compiler/smoke/Smoke.kts",
+                                                                   "-jar", resultJar.getAbsolutePath(),
+                                                                   "-stdlib", stdlib.getAbsolutePath());
+            Assert.assertEquals("compilation completed with non-zero code", KotlinCompiler.ExitCode.OK, rv);
             FileInputStream fileInputStream = new FileInputStream(resultJar);
             try {
                 JarInputStream is = new JarInputStream(fileInputStream);

idea/src/org/jetbrains/jet/plugin/compiler/JetCompiler.java

@@ -274,8 +274,10 @@ public class JetCompiler implements TranslatingCompiler {
             context.addMessage(INFORMATION, "Invoking in-process compiler " + compilerClassName + " with arguments " + Arrays.asList(arguments), "", -1, -1);
             
             Object rc = exec.invoke(kompiler.newInstance(), out, arguments);
-            if (rc instanceof Integer) {
-                return ((Integer) rc).intValue();
+            // exec() returns a KotlinCompiler.ExitCode object, that class is not accessible here,
+            // so we take it's contents through reflection
+            if ("org.jetbrains.jet.cli.KotlinCompiler.ExitCode".equals(rc.getClass().getCanonicalName())) {
+                return (Integer) rc.getClass().getMethod("getCode").invoke(rc);
             }
             else {
                 throw new IllegalStateException("Unexpected return: " + rc);

idea/tests/org/jetbrains/jet/plugin/libraries/LibrariesTest.java

@@ -150,8 +150,8 @@ public class LibrariesTest extends PlatformTestCase {
     protected void setUp() throws Exception {
         super.setUp();
         String libraryDir = FileUtil.getTempDirectory();
-        int compilerExec = new KotlinCompiler().exec("-src", TEST_DATA_PATH + "/library", "-output", libraryDir);
-        assertEquals(0, compilerExec);
+        KotlinCompiler.ExitCode compilerExec = new KotlinCompiler().exec("-src", TEST_DATA_PATH + "/library", "-output", libraryDir);
+        assertEquals(KotlinCompiler.ExitCode.OK, compilerExec);
         myLibraryDir = LocalFileSystem.getInstance().findFileByPath(libraryDir);
         assertNotNull(myLibraryDir);
 
@@ -168,4 +168,4 @@ public class LibrariesTest extends PlatformTestCase {
             }
         });
     }
-}
+}