next step for source map #6

src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java

@@ -34,6 +34,7 @@ import de.inetsoftware.jwebassembly.module.FunctionName;
 import de.inetsoftware.jwebassembly.module.ModuleWriter;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
 import de.inetsoftware.jwebassembly.module.WasmTarget;
+import de.inetsoftware.jwebassembly.sourcemap.SourceMapWriter;
 import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ArrayOperator;
 import de.inetsoftware.jwebassembly.wasm.NamedStorageType;
@@ -82,6 +83,8 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
 
     private int                         exceptionSignatureIndex       = -1;
 
+    private String                      javaSourceFile;
+
     /**
      * Create new instance.
      * 
@@ -202,12 +205,16 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
         if( size == 0 ) {
             return;
         }
+        SourceMapWriter sourceMap = new SourceMapWriter();
         WasmOutputStream stream = new WasmOutputStream();
         stream.writeVaruint32( size );
         for( Function func : functions.values() ) {
             func.functionsStream.writeTo( stream );
         }
         wasm.writeSection( SectionType.Code, stream );
+        if( createSourceMap ) {
+            sourceMap.generate( target.getSourceMapOutput() );
+        }
     }
 
     /**
@@ -358,9 +365,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
     @Override
     protected void writeMethodStart( FunctionName name, String sourceFile ) throws IOException {
         function = getFunction( name );
-        if( createSourceMap ) {
+        this.javaSourceFile = sourceFile;
-            function.sourceFile = sourceFile;
-        }
         functionType = new FunctionTypeEntry();
         codeStream.reset();
         locals.clear();
@@ -409,7 +414,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
     @Override
     protected void markCodePosition( int javaCodePosition ) {
         if( createSourceMap ) {
-            function.markCodePosition( codeStream.size(), javaCodePosition );
+            function.markCodePosition( codeStream.size(), javaCodePosition, javaSourceFile );
         }
     }
 

src/de/inetsoftware/jwebassembly/binary/Function.java

@@ -16,8 +16,11 @@
 package de.inetsoftware.jwebassembly.binary;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 
+import de.inetsoftware.jwebassembly.sourcemap.SourceMapping;
+
 /**
  * An entry in the function section of the WebAssembly.
  * 
@@ -25,15 +28,15 @@ import java.util.List;
  */
 class Function extends SectionEntry {
 
-    int id;
+    int                      id;
 
-    int typeId;
+    int                      typeId;
 
-    List<String> paramNames;
+    List<String>             paramNames;
 
-    WasmOutputStream functionsStream;
+    WasmOutputStream         functionsStream;
 
-    String sourceFile;
+    ArrayList<SourceMapping> sourceMappings;
 
     /**
      * {@inheritDoc}
@@ -48,12 +51,15 @@ class Function extends SectionEntry {
      * 
      * @param streamPosition
      *            the position in the function stream
-     * @param javaCodePosition
+     * @param javaSourceLine
      *            the position in the Java Source file
+     * @param sourceFileName
+     *            the name of the Java source file
      */
-    void markCodePosition( int streamPosition, int javaCodePosition ) {
+    void markCodePosition( int streamPosition, int javaSourceLine, String sourceFileName ) {
-        if( sourceFile != null ) {
+        if( sourceMappings == null ) {
-        // TODO Auto-generated method stub
+            sourceMappings = new ArrayList<>();
         }
+        sourceMappings.add( new SourceMapping( streamPosition, javaSourceLine, sourceFileName ) );
     }
 }

src/de/inetsoftware/jwebassembly/module/WasmTarget.java

@@ -21,6 +21,9 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 
 import javax.annotation.Nonnull;
 
@@ -33,6 +36,8 @@ public class WasmTarget implements Closeable {
 
     private OutputStream output;
 
+    private Writer       sourceMap;
+
     /**
      * Create a target with a file.
      * 
@@ -68,6 +73,21 @@ public class WasmTarget implements Closeable {
         return output;
     }
 
+    /**
+     * Get the source map OutputStream
+     * 
+     * @return the stream
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    @Nonnull
+    public Writer getSourceMapOutput() throws IOException {
+        if( sourceMap == null && file != null ) {
+            sourceMap = new OutputStreamWriter( new BufferedOutputStream( new FileOutputStream( file + ".map" ) ), StandardCharsets.UTF_8 );
+        }
+        return sourceMap;
+    }
+
     /**
      * Close all streams
      * 
@@ -76,6 +96,11 @@ public class WasmTarget implements Closeable {
      */
     @Override
     public void close() throws IOException {
-        output.close();
+        if( output != null ) {
+            output.close();
+        }
+        if( sourceMap != null ) {
+            sourceMap.close();
+        }
     }
 }

src/de/inetsoftware/jwebassembly/sourcemap/Base64VLQ.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2019 Volker Berlin (i-net software)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package de.inetsoftware.jwebassembly.sourcemap;
+
+import java.io.IOException;
+
+/**
+ * Encode an integer value as Base64VLQ
+ */
+class Base64VLQ {
+    private static final int    VLQ_BASE_SHIFT       = 5;
+
+    private static final int    VLQ_BASE             = 1 << VLQ_BASE_SHIFT;
+
+    private static final int    VLQ_BASE_MASK        = VLQ_BASE - 1;
+
+    private static final int    VLQ_CONTINUATION_BIT = VLQ_BASE;
+
+    private static final String BASE64_MAP           = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+    /**
+     * no instance
+     */
+    private Base64VLQ() {
+        // nothing
+    }
+
+    /**
+     * Move the signet bit from the first position (two-complement value) to the last bit position.
+     * 
+     * examples: 1 -> 2; -1 -> 3; 2 -> 4; -2 -> 5
+     * 
+     * @param value
+     *            two-complement value
+     * @return converted value
+     */
+    private static int toVLQSigned( int value ) {
+        return (value < 0) ? (((-value) << 1) + 1) : ((value << 1) + 0);
+    }
+
+    /**
+     * Writes a VLQ encoded value to the provide target.
+     * 
+     * @param out
+     *            the target
+     * @param value
+     *            the value
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    static void appendBase64VLQ( Appendable out, int value ) throws IOException {
+        value = toVLQSigned( value );
+        do {
+            int digit = value & VLQ_BASE_MASK;
+            value >>>= VLQ_BASE_SHIFT;
+            if( value > 0 ) {
+                digit |= VLQ_CONTINUATION_BIT;
+            }
+            out.append( BASE64_MAP.charAt( digit ) );
+        } while( value > 0 );
+    }
+}

src/de/inetsoftware/jwebassembly/sourcemap/SourceMapWriter.java

@@ -0,0 +1,240 @@
+/*
+ * Copyright 2019 Volker Berlin (i-net software)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package de.inetsoftware.jwebassembly.sourcemap;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map.Entry;
+
+/**
+ * Generates Source Map version 3.
+ *
+ * https://sourcemaps.info/spec.html
+ */
+public class SourceMapWriter {
+
+    private List<SourceMapping>                  mappings        = new ArrayList<>();
+
+    private LinkedHashMap<String, Integer> sourceFileNames = new LinkedHashMap<String, Integer>();
+
+    private int                            nextSourceFileNameIndex;
+
+    /**
+     * Adds a mapping for the given node. Mappings must be added in order.
+     * 
+     * @param mapping
+     *            the mapping
+     */
+    public void addMapping( SourceMapping mapping ) {
+        if( !sourceFileNames.containsKey( mapping.getSourceFileName() ) ) {
+            sourceFileNames.put( mapping.getSourceFileName(), nextSourceFileNameIndex );
+            nextSourceFileNameIndex++;
+        }
+
+        mappings.add( mapping );
+    }
+
+    /**
+     * https://sourcemaps.info/spec.html
+     * 
+     * @param out
+     *            the target
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    public void generate( Appendable out ) throws IOException {
+        out.append( "{\n" );
+        appendJsonField( out, "version", "3" );
+
+        // the source file names
+        out.append( ",\n" );
+        appendJsonField( out, "sources", "[" );
+        appendSourceFileNames( out );
+        out.append( "]" );
+
+        // WebAssembly does not have symbol names
+        out.append( ",\n" );
+        appendJsonField( out, "names", "[]" );
+
+        // generate the mappings
+        out.append( ",\n" );
+        appendJsonField( out, "mappings", "" );
+        (new Generator( out )).appendLineMappings();
+        out.append( "\n}" );
+    }
+
+    /**
+     * Write source file names.
+     * 
+     * @param out
+     *            the target
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    private void appendSourceFileNames( Appendable out ) throws IOException {
+        boolean isFirst = true;
+        for( Entry<String, Integer> entry : sourceFileNames.entrySet() ) {
+            String key = entry.getKey();
+            if( isFirst ) {
+                isFirst = false;
+            } else {
+                out.append( ',' );
+            }
+            appendQuoteString( out, key );
+        }
+    }
+
+    /**
+     * Write the field name to JSON source map.
+     * 
+     * @param out
+     *            the target
+     * @param name
+     *            the field name
+     * @param value
+     *            optional value
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    private static void appendJsonField( Appendable out, String name, CharSequence value ) throws IOException {
+        out.append( '\"' );
+        out.append( name );
+        out.append( "\":" );
+        out.append( value );
+    }
+
+    /**
+     * Write a quoted string to the JSON.
+     * 
+     * @param out
+     *            the target
+     * @param str
+     *            the unquoted string
+     * @throws IOException
+     *             if any I/O error occur
+     */
+    private static void appendQuoteString( Appendable out, String str ) throws IOException {
+        out.append( '"' );
+        for( int i = 0; i < str.length(); i++ ) {
+            char ch = str.charAt( i );
+            switch( ch ) {
+                case '\\':
+                case '\"':
+                    out.append( '\\' );
+                    break;
+                default:
+                    if( ch <= 0x1f ) {
+                        out.append( "\\u" );
+                        out.append( Character.forDigit( (ch >> 12) & 0xF, 16 ) );
+                        out.append( Character.forDigit( (ch >> 8) & 0xF, 16 ) );
+                        out.append( Character.forDigit( (ch >> 4) & 0xF, 16 ) );
+                        out.append( Character.forDigit( ch & 0xF, 16 ) );
+                        continue;
+                    }
+            }
+            out.append( ch );
+        }
+        out.append( '\"' );
+    }
+
+    /**
+     * The generator of the source map
+     */
+    private class Generator {
+
+        private final Appendable out;
+
+        private int              previousLine = -1;
+
+        private int              previousColumn;
+
+        private int              previousSourceFileNameId;
+
+        private int              previousSourceLine;
+
+        private int              previousSourceColumn;
+
+        /**
+         * Create an instance.
+         * 
+         * @param out
+         *            the target for the source map
+         */
+        Generator( Appendable out ) {
+            this.out = out;
+        }
+
+        /**
+         * Append the mappings to the source map.
+         * 
+         * @throws IOException
+         *             if any I/O error occur
+         */
+        void appendLineMappings() throws IOException {
+            out.append( '\"' );
+            for( SourceMapping mapping : mappings ) {
+                int generatedLine = 1; // ever 1 for WebAssembly
+                int generatedColumn = mapping.getGeneratedColumn();
+
+                if( generatedLine > 0 && previousLine != generatedLine ) {
+                    int start = previousLine == -1 ? 0 : previousLine;
+                    for( int i = start; i < generatedLine; i++ ) {
+                        out.append( ';' );
+                    }
+                }
+
+                if( previousLine != generatedLine ) {
+                    previousColumn = 0;
+                } else {
+                    out.append( ',' );
+                }
+
+                writeEntry( mapping );
+                previousLine = generatedLine;
+                previousColumn = generatedColumn;
+            }
+            out.append( ";\"" );
+        }
+
+        /**
+         * Write a single single mapping to the source map.
+         * 
+         * @param mapping
+         *            the mapping
+         * @throws IOException
+         *             if any I/O error occur
+         */
+        void writeEntry( SourceMapping mapping ) throws IOException {
+            int column = mapping.getGeneratedColumn();
+            Base64VLQ.appendBase64VLQ( out, column - previousColumn );
+            previousColumn = column;
+
+            int sourceId = sourceFileNames.get( mapping.getSourceFileName() );
+            Base64VLQ.appendBase64VLQ( out, sourceId - previousSourceFileNameId );
+            previousSourceFileNameId = sourceId;
+
+            int srcline = mapping.getSourceLine();
+            int srcColumn = 0; // ever 0 for Java byte code because the line table does not support columns
+            Base64VLQ.appendBase64VLQ( out, srcline - previousSourceLine );
+            previousSourceLine = srcline;
+
+            Base64VLQ.appendBase64VLQ( out, srcColumn - previousSourceColumn );
+            previousSourceColumn = srcColumn;
+        }
+    }
+}

src/de/inetsoftware/jwebassembly/sourcemap/SourceMapping.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2019 Volker Berlin (i-net software)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package de.inetsoftware.jwebassembly.sourcemap;
+
+/**
+ * Mapping for Source Map.
+ */
+public class SourceMapping {
+    private final int    generatedColumn;
+
+    private final int    sourceLine;
+
+    private final String sourceFileName;
+
+    /**
+     * Create a mapping between a Java code line and a WebAssembly code position
+     * 
+     * @param generatedColumn
+     *            position in WebAssembly
+     * @param sourceLine
+     *            Java source line
+     * @param sourceFileName
+     *            Java source file
+     */
+    public SourceMapping( int generatedColumn, int sourceLine, String sourceFileName ) {
+        this.generatedColumn = generatedColumn;
+        this.sourceLine = sourceLine;
+        this.sourceFileName = sourceFileName;
+    }
+
+    /**
+     * The generated column. This is equals to the binary offset in the *.wasm file
+     * 
+     * @return binary offset
+     */
+    int getGeneratedColumn() {
+        return generatedColumn;
+    }
+
+    /**
+     * The source line
+     * 
+     * @return the line number
+     */
+    int getSourceLine() {
+        return sourceLine;
+    }
+
+    /**
+     * Source file name
+     * 
+     * @return the name
+     */
+    String getSourceFileName() {
+        return sourceFileName;
+    }
+}

test/de/inetsoftware/jwebassembly/sourcemap/SourceMapWriterTest.java

@@ -0,0 +1,30 @@
+package de.inetsoftware.jwebassembly.sourcemap;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+public class SourceMapWriterTest {
+
+    @Test
+    public void simple() throws IOException {
+        SourceMapWriter map = new SourceMapWriter();
+
+        map.addMapping( new SourceMapping( 0, 0, "Test1.java" ) );
+        map.addMapping( new SourceMapping( 5, 1, "Test1.java" ) );
+        map.addMapping( new SourceMapping( 0, 4, "Test2.java" ) );
+        map.addMapping( new SourceMapping( 5, 9, "Test2.java" ) );
+
+        StringBuilder generate = new StringBuilder();
+        map.generate( generate );
+        String expected = "{\n" + 
+                        "\"version\":3,\n" + 
+                        "\"sources\":[\"Test1.java\",\"Test2.java\"],\n" + 
+                        "\"names\":[],\n" + 
+                        "\"mappings\":\";AAAA,KACA,LCGA,KAKA;\"\n" + 
+                        "}";
+        assertEquals( expected, generate.toString() );
+    }
+}