next step for source map #6

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

@@ -34,6 +34,7 @@
 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 @@ private void writeCodeSection() throws IOException {
         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 @@ protected void writeExport( FunctionName name, String exportName ) throws IOExce
     @Override
     protected void writeMethodStart( FunctionName name, String sourceFile ) throws IOException {
         function = getFunction( name );
-        if( createSourceMap ) {
-            function.sourceFile = sourceFile;
-        }
+        this.javaSourceFile = sourceFile;
         functionType = new FunctionTypeEntry();
         codeStream.reset();
         locals.clear();
@@ -409,7 +414,7 @@ protected void writeMethodParamFinish() throws IOException {
     @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

@@ -16,24 +16,27 @@
 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.
  * 
  * @author Volker Berlin
  */
 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 @@ void writeSectionEntry( WasmOutputStream stream ) throws IOException {
      * 
      * @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 ) {
-        if( sourceFile != null ) {
-        // TODO Auto-generated method stub
+    void markCodePosition( int streamPosition, int javaSourceLine, String sourceFileName ) {
+        if( sourceMappings == null ) {
+            sourceMappings = new ArrayList<>();
         }
+        sourceMappings.add( new SourceMapping( streamPosition, javaSourceLine, sourceFileName ) );
     }
 }

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

@@ -21,6 +21,9 @@
 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 OutputStream getWasmOutput() throws IOException {
         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 OutputStream getWasmOutput() throws IOException {
      */
     @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 );
+    }
+}