diff --git a/ChangeLog b/ChangeLog
index b47aec2..da220ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,30 @@
+Wed May 13 01:22:12 2009  Minero Aoki  <aamine@loveruby.net>
+
+	* net/loveruby/cflat/utils/CommandUtils.java: accept a list of
+	  string instead of CommandArg.
+
+	* net/loveruby/cflat/sysdep/Linker.java: ditto.
+
+	* net/loveruby/cflat/sysdep/LinkerOptions.java: ditto.
+
+	* net/loveruby/cflat/sysdep/GNULinker.java: ditto.
+
+	* net/loveruby/cflat/sysdep/AssemblerOptions.java: ditto.
+
+	* net/loveruby/cflat/sysdep/GNUAssembler.java: ditto.
+
+	* net/loveruby/cflat/utils/CommandArgStr.java ->
+	  compiler/LdOption.java
+
+	* net/loveruby/cflat/utils/CommandArg.java -> compiler/LdArg.java
+
+	* net/loveruby/cflat/compiler/SourceFile.java: CommandArg ->
+	  LdArg.
+
+	* net/loveruby/cflat/compiler/Compiler.java: ditto.
+
+	* net/loveruby/cflat/compiler/Options.java: ditto.
+
 Mon May 11 03:17:32 2009  Minero Aoki  <aamine@loveruby.net>
 
 	* net/loveruby/cflat/compiler/Compiler.java: objectify assembler.
diff --git a/net/loveruby/cflat/compiler/Compiler.java b/net/loveruby/cflat/compiler/Compiler.java
index b8ea8bf..f1140c3 100644
--- a/net/loveruby/cflat/compiler/Compiler.java
+++ b/net/loveruby/cflat/compiler/Compiler.java
@@ -197,13 +197,13 @@ public class Compiler {
     }
 
     private void generateExecutable(Options opts) throws IPCException {
-        opts.linker(errorHandler)
-            .generateExecutable(opts.exeFileName(), opts.ldOptions());
+        opts.linker(errorHandler).generateExecutable(
+                opts.exeFileName(), opts.ldArgs(), opts.ldOptions());
     }
 
     private void generateSharedLibrary(Options opts) throws IPCException {
-        opts.linker(errorHandler)
-            .generateSharedLibrary(opts.soFileName(), opts.ldOptions());
+        opts.linker(errorHandler).generateSharedLibrary(
+                opts.soFileName(), opts.ldArgs(), opts.ldOptions());
     }
 
     private void writeFile(String path, String str)
diff --git a/net/loveruby/cflat/compiler/LdArg.java b/net/loveruby/cflat/compiler/LdArg.java
new file mode 100644
index 0000000..2c519d1
--- /dev/null
+++ b/net/loveruby/cflat/compiler/LdArg.java
@@ -0,0 +1,6 @@
+package net.loveruby.cflat.compiler;
+
+interface LdArg {
+    String toString();
+    boolean isSourceFile();
+}
diff --git a/net/loveruby/cflat/utils/CommandArgStr.java b/net/loveruby/cflat/compiler/LdOption.java
similarity index 59%
rename from net/loveruby/cflat/utils/CommandArgStr.java
rename to net/loveruby/cflat/compiler/LdOption.java
index 75a86dd..2b3f069 100644
--- a/net/loveruby/cflat/utils/CommandArgStr.java
+++ b/net/loveruby/cflat/compiler/LdOption.java
@@ -1,9 +1,9 @@
-package net.loveruby.cflat.utils;
+package net.loveruby.cflat.compiler;
 
-public class CommandArgStr implements CommandArg {
+class LdOption implements LdArg {
     private String arg;
 
-    public CommandArgStr(String arg) {
+    LdOption(String arg) {
         this.arg = arg;
     }
 
diff --git a/net/loveruby/cflat/compiler/Options.java b/net/loveruby/cflat/compiler/Options.java
index d015d2e..0dac6eb 100644
--- a/net/loveruby/cflat/compiler/Options.java
+++ b/net/loveruby/cflat/compiler/Options.java
@@ -3,15 +3,16 @@ import net.loveruby.cflat.parser.LibraryLoader;
 import net.loveruby.cflat.type.TypeTable;
 import net.loveruby.cflat.asm.*;
 import net.loveruby.cflat.sysdep.*;
-import net.loveruby.cflat.sysdep.X86Linux;
-import net.loveruby.cflat.utils.CommandArg;
 import net.loveruby.cflat.utils.ErrorHandler;
 import net.loveruby.cflat.exception.*;
-import java.util.*;
-import java.io.*;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.io.PrintStream;
 
 class Options {
-    CompilerMode mode;
+    CompilerMode mode = CompilerMode.Link;
     LibraryLoader loader = new LibraryLoader();
     Platform platform = new X86Linux();
     String outputFileName;
@@ -20,6 +21,8 @@ class Options {
     CodeGeneratorOptions genOptions = new CodeGeneratorOptions();
     AssemblerOptions asOptions = new AssemblerOptions();
     LinkerOptions ldOptions = new LinkerOptions();
+    List<LdArg> ldArgs;
+    List<SourceFile> sourceFiles;
 
     CompilerMode mode() {
         return mode;
@@ -45,29 +48,20 @@ class Options {
         return getOutputFileName(".so");
     }
 
+    static private final String DEFAULT_OUTPUT_FILE_NAME = "a.out";
+
     private String getOutputFileName(String newExt) {
         if (outputFileName != null) {
             return outputFileName;
         }
-        List<SourceFile> srcs = sourceFiles();
-        if (srcs.size() == 1) {
-            return srcs.get(0).linkedFileName(this, newExt);
+        if (sourceFiles.size() == 1) {
+            return sourceFiles.get(0).linkedFileName(this, newExt);
         }
         else {
-            return "a.out";
+            return DEFAULT_OUTPUT_FILE_NAME;
         }
     }
 
-    private List<SourceFile> sourceFiles() {
-        List<SourceFile> result = new ArrayList<SourceFile>();
-        for (CommandArg arg : ldOptions.args()) {
-            if (arg.isSourceFile()) {
-                result.add((SourceFile)arg);
-            }
-        }
-        return result;
-    }
-
     String outputFileName() {
         return this.outputFileName;
     }
@@ -108,13 +102,21 @@ class Options {
         return ldOptions;
     }
 
+    List<String> ldArgs() {
+        List<String> result = new ArrayList<String>();
+        for (LdArg arg : ldArgs) {
+            result.add(arg.toString());
+        }
+        return result;
+    }
+
     boolean isGeneratingSharedLibrary() {
         return ldOptions.generatingSharedLibrary;
     }
 
-    /** Returns List<SourceFile>. */
     List<SourceFile> parse(List<String> argsList) {
-        List<SourceFile> srcs = new ArrayList<SourceFile>();
+        sourceFiles = new ArrayList<SourceFile>();
+        ldArgs = new ArrayList<LdArg>();
         ListIterator<String> args = argsList.listIterator();
         while (args.hasNext()) {
             String arg = args.next();
@@ -166,7 +168,7 @@ class Options {
                     asOptions.addArg(nextArg(arg, args));
                 }
                 else if (arg.equals("-static")) {
-                    ldOptions.addArg(arg);
+                    addLdArg(arg);
                 }
                 else if (arg.equals("-shared")) {
                     ldOptions.generatingSharedLibrary = true;
@@ -175,18 +177,18 @@ class Options {
                     ldOptions.generatingPIE = true;
                 }
                 else if (arg.equals("--readonly-plt")) {
-                    ldOptions.addArg("-z");
-                    ldOptions.addArg("combreloc");
-                    ldOptions.addArg("-z");
-                    ldOptions.addArg("now");
-                    ldOptions.addArg("-z");
-                    ldOptions.addArg("relro");
+                    addLdArg("-z");
+                    addLdArg("combreloc");
+                    addLdArg("-z");
+                    addLdArg("now");
+                    addLdArg("-z");
+                    addLdArg("relro");
                 }
                 else if (arg.startsWith("-L")) {
-                    ldOptions.addArg("-L" + getOptArg(arg, args));
+                    addLdArg("-L" + getOptArg(arg, args));
                 }
                 else if (arg.startsWith("-l")) {
-                    ldOptions.addArg("-l" + getOptArg(arg, args));
+                    addLdArg("-l" + getOptArg(arg, args));
                 }
                 else if (arg.equals("-nostartfiles")) {
                     ldOptions.noStartFiles = true;
@@ -200,11 +202,11 @@ class Options {
                 }
                 else if (arg.startsWith("-Wl,")) {
                     for (String opt : parseCommaSeparatedOptions(arg)) {
-                        ldOptions.addArg(opt);
+                        addLdArg(opt);
                     }
                 }
                 else if (arg.equals("-Xlinker")) {
-                    ldOptions.addArg(nextArg(arg, args));
+                    addLdArg(nextArg(arg, args));
                 }
                 else if (arg.equals("-v")) {
                     verbose = true;
@@ -225,33 +227,42 @@ class Options {
                 }
             }
             else {
-                // source file
-                addSourceFile(srcs, arg);
+                ldArgs.add(new SourceFile(arg));
             }
         }
         // args has more arguments when "--" is appeared.
         while (args.hasNext()) {
-            addSourceFile(srcs, args.next());
+            ldArgs.add(new SourceFile(args.next()));
         }
-        if (srcs.isEmpty()) parseError("no input file");
-        if (mode == null) {
-            mode = CompilerMode.Link;
+
+        sourceFiles = selectSourceFiles(ldArgs);
+        if (sourceFiles.isEmpty()) {
+            parseError("no input file");
         }
-        if (! isLinkRequired() && outputFileName != null && srcs.size() > 1) {
-            parseError("-o option requires only 1 input not on linking");
+        if (outputFileName != null
+                && sourceFiles.size() > 1
+                && ! isLinkRequired()) {
+            parseError("-o option requires only 1 input (except linking)");
         }
-        return srcs;
+        return sourceFiles;
     }
 
     private void parseError(String msg) {
         throw new OptionParseError(msg);
     }
 
-    private void addSourceFile(List<SourceFile> srcs, String sourceName) {
-        SourceFile src = new SourceFile(sourceName);
-        srcs.add(src);
-        // Original argument order does matter when linking.
-        ldOptions.addArg(src);
+    private void addLdArg(String arg) {
+        ldArgs.add(new LdOption(arg));
+    }
+
+    private List<SourceFile> selectSourceFiles(List<LdArg> args) {
+        List<SourceFile> result = new ArrayList<SourceFile>();
+        for (LdArg arg : args) {
+            if (arg.isSourceFile()) {
+                result.add((SourceFile)arg);
+            }
+        }
+        return result;
     }
 
     private String getOptArg(String opt, ListIterator<String> args) {
diff --git a/net/loveruby/cflat/compiler/SourceFile.java b/net/loveruby/cflat/compiler/SourceFile.java
index 1e58f62..0c4d33d 100644
--- a/net/loveruby/cflat/compiler/SourceFile.java
+++ b/net/loveruby/cflat/compiler/SourceFile.java
@@ -1,66 +1,72 @@
 package net.loveruby.cflat.compiler;
-import net.loveruby.cflat.utils.CommandArg;
 import java.io.File;
 
-// package private
-class SourceFile implements CommandArg {
+class SourceFile implements LdArg {
     private String originalName;
     private String currentName;
 
-    public SourceFile(String name) {
+    SourceFile(String name) {
         this.originalName = name;
         this.currentName = name;
     }
 
-    public String name() {
+    public boolean isSourceFile() {
+        return true;
+    }
+
+    public String toString() {
+        return currentName;
+    }
+
+    String name() {
         return originalName();
     }
 
-    public String originalName() {
+    String originalName() {
         return this.originalName;
     }
 
-    public String currentName() {
+    String currentName() {
         return this.currentName;
     }
 
-    public void setCurrentName(String name) {
+    void setCurrentName(String name) {
         this.currentName = name;
     }
 
-    public boolean isCflatSource() {
+    boolean isCflatSource() {
         return extName(currentName).equals(".cb");
     }
 
-    public boolean isAssemblySource() {
+    boolean isAssemblySource() {
         return extName(currentName).equals(".s");
     }
 
-    public boolean isObjectFile() {
+    boolean isObjectFile() {
         return extName(currentName).equals(".o");
     }
 
-    public boolean isSharedLibrary() {
+    boolean isSharedLibrary() {
         return extName(currentName).equals(".so");
     }
 
-    public boolean isStaticLibrary() {
+    boolean isStaticLibrary() {
         return extName(currentName).equals(".a");
     }
 
-    public boolean isExecutable() {
+    boolean isExecutable() {
         return extName(currentName).equals("");
     }
 
-    public String asmFileName(Options opts) {
+    String asmFileName(Options opts) {
         return or(opts.outputFileNameFor(CompilerMode.Compile), replaceExt(".s"));
     }
 
-    public String objFileName(Options opts) {
+    String objFileName(Options opts) {
         return or(opts.outputFileNameFor(CompilerMode.Assemble), replaceExt(".o"));
     }
 
-    public String linkedFileName(Options opts, String newExt) {
+    String linkedFileName(Options opts, String newExt) {
         return or(opts.outputFileName, replaceExt(newExt));
     }
 
@@ -90,12 +96,4 @@ class SourceFile implements CommandArg {
         if (idx < 0) return "";
         return path.substring(idx);
     }
-
-    public boolean isSourceFile() {
-        return true;
-    }
-
-    public String toString() {
-        return currentName;
-    }
 }
diff --git a/net/loveruby/cflat/sysdep/AssemblerOptions.java b/net/loveruby/cflat/sysdep/AssemblerOptions.java
index c700c2f..79efbc0 100644
--- a/net/loveruby/cflat/sysdep/AssemblerOptions.java
+++ b/net/loveruby/cflat/sysdep/AssemblerOptions.java
@@ -1,18 +1,12 @@
 package net.loveruby.cflat.sysdep;
-import net.loveruby.cflat.utils.CommandArg;
-import net.loveruby.cflat.utils.CommandArgStr;
 import java.util.List;
 import java.util.ArrayList;
 
 public class AssemblerOptions {
     public boolean verbose = false;
-    List<CommandArg> args = new ArrayList<CommandArg>();
+    List<String> args = new ArrayList<String>();
 
     public void addArg(String a) {
-        args.add(new CommandArgStr(a));
-    }
-
-    public void addArg(CommandArg a) {
         args.add(a);
     }
 }
diff --git a/net/loveruby/cflat/sysdep/GNUAssembler.java b/net/loveruby/cflat/sysdep/GNUAssembler.java
index 1b33684..633bc8b 100644
--- a/net/loveruby/cflat/sysdep/GNUAssembler.java
+++ b/net/loveruby/cflat/sysdep/GNUAssembler.java
@@ -1,7 +1,5 @@
 package net.loveruby.cflat.sysdep;
 import net.loveruby.cflat.utils.CommandUtils;
-import net.loveruby.cflat.utils.CommandArg;
-import net.loveruby.cflat.utils.CommandArgStr;
 import net.loveruby.cflat.utils.ErrorHandler;
 import net.loveruby.cflat.exception.IPCException;
 import java.util.List;
@@ -16,16 +14,12 @@ class GNUAssembler implements Assembler {
 
     public void assemble(String srcPath, String destPath,
                             AssemblerOptions opts) throws IPCException {
-        List<CommandArg> cmd = new ArrayList<CommandArg>();
-        cmd.add(arg("as"));
+        List<String> cmd = new ArrayList<String>();
+        cmd.add("as");
         cmd.addAll(opts.args);
-        cmd.add(arg("-o"));
-        cmd.add(arg(destPath));
-        cmd.add(arg(srcPath));
+        cmd.add("-o");
+        cmd.add(destPath);
+        cmd.add(srcPath);
         CommandUtils.invoke(cmd, errorHandler, opts.verbose);
     }
-
-    private CommandArg arg(String a) {
-        return new CommandArgStr(a);
-    }
 }
diff --git a/net/loveruby/cflat/sysdep/GNULinker.java b/net/loveruby/cflat/sysdep/GNULinker.java
index 14f2c91..fffc6b9 100644
--- a/net/loveruby/cflat/sysdep/GNULinker.java
+++ b/net/loveruby/cflat/sysdep/GNULinker.java
@@ -1,7 +1,5 @@
 package net.loveruby.cflat.sysdep;
 import net.loveruby.cflat.utils.CommandUtils;
-import net.loveruby.cflat.utils.CommandArg;
-import net.loveruby.cflat.utils.CommandArgStr;
 import net.loveruby.cflat.utils.ErrorHandler;
 import net.loveruby.cflat.exception.IPCException;
 import java.util.List;
@@ -20,56 +18,52 @@ class GNULinker implements Linker {
         this.errorHandler = errorHandler;
     }
 
-    public void generateExecutable(
-            String destPath, LinkerOptions opts) throws IPCException {
-        List<CommandArg> cmd = new ArrayList<CommandArg>();
-        cmd.add(arg("ld"));
-        cmd.add(arg("-dynamic-linker"));
-        cmd.add(arg(DYNAMIC_LINKER));
+    public void generateExecutable(String destPath,
+            List<String> args, LinkerOptions opts) throws IPCException {
+        List<String> cmd = new ArrayList<String>();
+        cmd.add("ld");
+        cmd.add("-dynamic-linker");
+        cmd.add(DYNAMIC_LINKER);
         if (opts.generatingPIE) {
-            cmd.add(arg("-pie"));
+            cmd.add("-pie");
         }
         if (! opts.noStartFiles) {
-            cmd.add(arg(opts.generatingPIE
+            cmd.add(opts.generatingPIE
                         ? C_RUNTIME_START_PIE
-                        : C_RUNTIME_START));
-            cmd.add(arg(C_RUNTIME_INIT));
+                        : C_RUNTIME_START);
+            cmd.add(C_RUNTIME_INIT);
         }
-        cmd.addAll(opts.args);
+        cmd.addAll(args);
         if (! opts.noDefaultLibs) {
-            cmd.add(arg("-lc"));
-            cmd.add(arg("-lcbc"));
+            cmd.add("-lc");
+            cmd.add("-lcbc");
         }
         if (! opts.noStartFiles) {
-            cmd.add(arg(C_RUNTIME_FINI));
+            cmd.add(C_RUNTIME_FINI);
         }
-        cmd.add(arg("-o"));
-        cmd.add(arg(destPath));
+        cmd.add("-o");
+        cmd.add(destPath);
         CommandUtils.invoke(cmd, errorHandler, opts.verbose);
     }
 
-    public void generateSharedLibrary(
-            String destPath, LinkerOptions opts) throws IPCException {
-        List<CommandArg> cmd = new ArrayList<CommandArg>();
-        cmd.add(arg("ld"));
-        cmd.add(arg("-shared"));
+    public void generateSharedLibrary(String destPath,
+            List<String> args, LinkerOptions opts) throws IPCException {
+        List<String> cmd = new ArrayList<String>();
+        cmd.add("ld");
+        cmd.add("-shared");
         if (! opts.noStartFiles) {
-            cmd.add(arg(C_RUNTIME_INIT));
+            cmd.add(C_RUNTIME_INIT);
         }
-        cmd.addAll(opts.args);
+        cmd.addAll(args);
         if (! opts.noDefaultLibs) {
-            cmd.add(arg("-lc"));
-            cmd.add(arg("-lcbc"));
+            cmd.add("-lc");
+            cmd.add("-lcbc");
         }
         if (! opts.noStartFiles) {
-            cmd.add(arg(C_RUNTIME_FINI));
+            cmd.add(C_RUNTIME_FINI);
         }
-        cmd.add(arg("-o"));
-        cmd.add(arg(destPath));
+        cmd.add("-o");
+        cmd.add(destPath);
         CommandUtils.invoke(cmd, errorHandler, opts.verbose);
     }
-
-    private CommandArg arg(String a) {
-        return new CommandArgStr(a);
-    }
 }
diff --git a/net/loveruby/cflat/sysdep/Linker.java b/net/loveruby/cflat/sysdep/Linker.java
index f0fbf8f..77d97c7 100644
--- a/net/loveruby/cflat/sysdep/Linker.java
+++ b/net/loveruby/cflat/sysdep/Linker.java
@@ -1,7 +1,10 @@
 package net.loveruby.cflat.sysdep;
 import net.loveruby.cflat.exception.IPCException;
+import java.util.List;
 
 public interface Linker {
-    void generateExecutable(String destPath, LinkerOptions opts) throws IPCException;
-    void generateSharedLibrary(String destPath, LinkerOptions opts) throws IPCException;
+    void generateExecutable(String destPath,
+            List<String> args, LinkerOptions opts) throws IPCException;
+    void generateSharedLibrary(String destPath,
+            List<String> args, LinkerOptions opts) throws IPCException;
 }
diff --git a/net/loveruby/cflat/sysdep/LinkerOptions.java b/net/loveruby/cflat/sysdep/LinkerOptions.java
index a498012..aa8f767 100644
--- a/net/loveruby/cflat/sysdep/LinkerOptions.java
+++ b/net/loveruby/cflat/sysdep/LinkerOptions.java
@@ -1,8 +1,4 @@
 package net.loveruby.cflat.sysdep;
-import net.loveruby.cflat.utils.CommandArg;
-import net.loveruby.cflat.utils.CommandArgStr;
-import java.util.List;
-import java.util.ArrayList;
 
 public class LinkerOptions {
     public boolean generatingSharedLibrary = false;
@@ -10,17 +6,4 @@ public class LinkerOptions {
     public boolean noStartFiles = false;
     public boolean noDefaultLibs = false;
     public boolean verbose = false;
-    List<CommandArg> args = new ArrayList<CommandArg>();
-
-    public void addArg(String a) {
-        args.add(new CommandArgStr(a));
-    }
-
-    public void addArg(CommandArg a) {
-        args.add(a);
-    }
-
-    public List<CommandArg> args() {
-        return this.args;
-    }
 }
diff --git a/net/loveruby/cflat/utils/CommandArg.java b/net/loveruby/cflat/utils/CommandArg.java
deleted file mode 100644
index f8526d1..0000000
--- a/net/loveruby/cflat/utils/CommandArg.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package net.loveruby.cflat.utils;
-
-public interface CommandArg {
-    public String toString();
-    public boolean isSourceFile();
-}
diff --git a/net/loveruby/cflat/utils/CommandUtils.java b/net/loveruby/cflat/utils/CommandUtils.java
index b7c55b8..e6b389e 100644
--- a/net/loveruby/cflat/utils/CommandUtils.java
+++ b/net/loveruby/cflat/utils/CommandUtils.java
@@ -5,13 +5,13 @@ import java.util.ArrayList;
 import java.io.*;
 
 abstract public class CommandUtils {
-    static public void invoke(List<CommandArg> cmdArgs,
+    static public void invoke(List<String> cmdArgs,
             ErrorHandler errorHandler, boolean debug) throws IPCException {
         if (debug) {
             dumpCommand(cmdArgs);
         }
         try {
-            String[] cmd = getStrings(cmdArgs);
+            String[] cmd = cmdArgs.toArray(new String[] {});
             Process proc = Runtime.getRuntime().exec(cmd);
             proc.waitFor();
             passThrough(proc.getInputStream());
@@ -32,20 +32,11 @@ abstract public class CommandUtils {
         }
     }
 
-    static private String[] getStrings(List<CommandArg> list) {
-        String[] result = new String[list.size()];
-        int idx = 0;
-        for (CommandArg arg : list) {
-            result[idx++] = arg.toString();
-        }
-        return result;
-    }
-
-    static private void dumpCommand(List<CommandArg> args) {
+    static private void dumpCommand(List<String> args) {
         String sep = "";
-        for (CommandArg arg : args) {
+        for (String arg : args) {
             System.out.print(sep); sep = " ";
-            System.out.print(arg.toString());
+            System.out.print(arg);
         }
         System.out.println("");
     }