[PLX-314] When forking javac, receive "The input line is too long" error from Windows

Author: carlos

plexus-compilers/plexus-compiler-javac/src/main/java/org/codehaus/plexus/compiler/javac/JavacCompiler.java

@@ -49,11 +49,13 @@
 import org.codehaus.plexus.util.StringUtils;
 import org.codehaus.plexus.util.cli.CommandLineException;
 import org.codehaus.plexus.util.cli.CommandLineUtils;
+import org.codehaus.plexus.util.cli.Commandline;
 
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.io.FileWriter;
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.lang.reflect.InvocationTargetException;
@@ -312,7 +314,15 @@ List compileOutOfProcess( File workingDirectory, String executable, String[] arg
 
         cli.setExecutable( executable );
 
-        cli.addArguments( args );
+        try
+        {
+            File argumentsFile = createFileWithArguments( args );
+            cli.addArguments( new String[] { "@" + argumentsFile.getCanonicalPath().replace( File.separatorChar, '/' ) } );
+        }
+        catch ( IOException e )
+        {
+            throw new CompilerException( "Error creating file with javac arguments", e );
+        }
 
         CommandLineUtils.StringStreamConsumer out = new CommandLineUtils.StringStreamConsumer();
 
@@ -589,4 +599,44 @@ public static CompilerError parseModernError( String error )
             return new CompilerError( "could not parse error message: " + error, isError );
         }
     }
+
+    /**
+     * put args into a temp file to be referenced using the @ option in javac command line
+     * @param args
+     * @return the temporary file wth the arguments
+     * @throws IOException
+     */
+    private File createFileWithArguments( String[] args )
+        throws IOException
+    {
+        PrintWriter writer = null;
+        try
+        {
+            File tempFile = File.createTempFile( JavacCompiler.class.getName(), "arguments" );
+            tempFile.deleteOnExit();
+
+            writer = new PrintWriter( new FileWriter( tempFile ) );
+
+            for ( int i = 0; i < args.length; i++ )
+            {
+                String argValue = args[i].replace( File.separatorChar, '/' );
+
+                writer.write( "\"" + argValue + "\"" );
+
+                writer.write( EOL );
+            }
+
+            writer.flush();
+
+            return tempFile;
+
+        }
+        finally
+        {
+            if ( writer != null )
+            {
+                writer.close();
+            }
+        }
+    }
 }

plexus-compilers/plexus-compiler-javac/src/test/java/org/codehaus/plexus/compiler/javac/JavacCompilerTest.java

@@ -24,22 +24,21 @@
  * SOFTWARE.
  */
 
-import org.codehaus.plexus.compiler.AbstractCompilerTest;
-import org.codehaus.plexus.compiler.CompilerConfiguration;
-import org.apache.maven.artifact.repository.layout.ArtifactRepositoryLayout;
-import org.apache.maven.artifact.repository.DefaultArtifactRepository;
-import org.apache.maven.artifact.repository.ArtifactRepository;
-import org.apache.maven.artifact.Artifact;
-import org.apache.maven.settings.io.xpp3.SettingsXpp3Reader;
-import org.apache.maven.settings.Settings;
-import org.apache.maven.model.Repository;
-
 import java.io.File;
 import java.io.FileReader;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 
+import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.repository.ArtifactRepository;
+import org.apache.maven.artifact.repository.DefaultArtifactRepository;
+import org.apache.maven.artifact.repository.layout.ArtifactRepositoryLayout;
+import org.apache.maven.settings.Settings;
+import org.apache.maven.settings.io.xpp3.SettingsXpp3Reader;
+import org.codehaus.plexus.compiler.AbstractCompilerTest;
+import org.codehaus.plexus.compiler.CompilerConfiguration;
+
 /**
  * @author <a href="mailto:jason@plexus.org">Jason van Zyl</a>
  * @version $Id$
@@ -163,6 +162,39 @@ public void testBuildCompilerArgsUnspecifiedVersion()
         internalTest( compilerConfiguration, expectedArguments );
     }
 
+    public void testCommandLineTooLongWhenForking()
+        throws Exception
+    {
+        List expectedArguments = new ArrayList();
+
+        CompilerConfiguration compilerConfiguration = new CompilerConfiguration();
+
+        populateArguments( compilerConfiguration, expectedArguments, false, false );
+
+        compilerConfiguration.setFork( true );
+
+        internalTest( compilerConfiguration, expectedArguments );
+
+        JavacCompiler compiler = (JavacCompiler) lookup( org.codehaus.plexus.compiler.Compiler.ROLE, getRoleHint() );
+
+        File destDir = new File( "target/test-classes-cmd" );
+        destDir.mkdirs();
+
+        /* fill the cmd line arguments, 300 is enough to make it break */
+        String[] args = new String[400];
+        args[0] = "-d";
+        args[1] = destDir.getAbsolutePath();
+        for ( int i = 2; i < args.length; i++ )
+        {
+            args[i] = "org/codehaus/foo/Person.java";
+        }
+
+        List messages = compiler.compileOutOfProcess( new File( getBasedir() + "/src/test-input/src/main" ), "javac",
+                                                      args );
+
+        assertEquals( "There were errors launching the external compiler: " + messages, 0, messages.size() );
+    }
+
     private void populateArguments( CompilerConfiguration compilerConfiguration, List expectedArguments,
                                     boolean suppressSourceVersion, boolean suppressEncoding )
     {