pass the method with signature to the VariableManager as fallback

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

@@ -25,6 +25,7 @@ import de.inetsoftware.classparser.CodeInputStream;
 import de.inetsoftware.classparser.ConstantClass;
 import de.inetsoftware.classparser.ConstantPool;
 import de.inetsoftware.classparser.ConstantRef;
+import de.inetsoftware.classparser.MethodInfo;
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ArrayOperator;
@@ -49,18 +50,19 @@ class JavaMethodWasmCodeBuilder extends WasmCodeBuilder {
      * 
      * @param code
      *            the Java method code
-     * @param hasReturn
+     * @param method
-     *            true, if the method has a return value; false, if it is void
+     *            the method with signature as fallback for a missing variable table
      * @throws WasmException
      *             if some Java code can't converted
      */
-    void buildCode( @Nonnull Code code, boolean hasReturn ) {
+    void buildCode( @Nonnull Code code, MethodInfo method ) {
         CodeInputStream byteCode = null;
         try {
-            reset( code.getLocalVariableTable() );
+            reset( code.getLocalVariableTable(), method );
             branchManager.reset( code );
 
             byteCode = code.getByteCode();
+            boolean hasReturn = !method.getType().endsWith( ")V" );
             writeCode( byteCode, code.getConstantPool(), hasReturn );
             calculateVariables();
         } catch( Exception ioex ) {

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

@@ -19,7 +19,6 @@ package de.inetsoftware.jwebassembly.module;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 
@@ -27,6 +26,7 @@ import javax.annotation.Nullable;
 
 import de.inetsoftware.classparser.LocalVariable;
 import de.inetsoftware.classparser.LocalVariableTable;
+import de.inetsoftware.classparser.MethodInfo;
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
@@ -78,8 +78,10 @@ class LocaleVariableManager {
      * 
      * @param variableTable
      *            variable table of the Java method.
+     * @param method
+     *            the method with signature as fallback for a missing variable table
      */
-    void reset( LocalVariableTable variableTable ) {
+    void reset( LocalVariableTable variableTable, MethodInfo method ) {
         size = 0;
 
         if( variableTable == null ) {
@@ -150,8 +152,24 @@ class LocaleVariableManager {
             var.name = findUniqueVarName( var.name );
         }
 
-        // add all missing slots that we can add self temporary variables
         int maxLocals = variableTable.getMaxLocals();
+
+        // add missing slots from signature
+        if( maxLocals > 0 && vars.length == 0 && method != null ) {
+            ValueTypeParser parser = new ValueTypeParser( method.getType(), types );
+            if( !method.isStatic() ) {
+                resetAddVar( ValueType.anyref );
+            }
+            while( size < maxLocals ) {
+                AnyType type = parser.next();
+                if( type == null ) {
+                    break;
+                }
+                resetAddVar( type );
+            }
+        }
+
+        // add all missing slots that we can add self temporary variables
         NEXT: for( int i = 0; i < maxLocals; i++ ) {
             for( int j = 0; j < size; j++ ) {
                 Variable var = variables[j];
@@ -159,16 +177,26 @@ class LocaleVariableManager {
                     continue NEXT;
                 }
             }
+            resetAddVar( null );
+        }
+    }
+
+    /**
+     * Add a variable in the reset with range.
+     * 
+     * @param type
+     *            the type of the variable
+     */
+    private void resetAddVar( AnyType type ) {
         ensureCapacity( size + 1 );
         Variable var = variables[size];
-            var.valueType = null;
+        var.valueType = type;
         var.name = null;
-            var.idx = i;
+        var.idx = size;
         var.startPos = 0;
         var.endPos = Integer.MAX_VALUE;
         size++;
     }
-    }
 
     /**
      * Find a unique variable name.

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

@@ -436,10 +436,10 @@ public class ModuleGenerator {
                 if( signature == null ) {
                     signature = method.getType();
                 }
-                watParser.parse( watCode, code == null ? -1 : code.getFirstLineNr() );
+                watParser.parse( watCode, method, code == null ? -1 : code.getFirstLineNr() );
                 return watParser;
             } else if( code != null ) { // abstract methods and interface methods does not have code
-                javaCodeBuilder.buildCode( code, !method.getType().endsWith( ")V" ) );
+                javaCodeBuilder.buildCode( code, method );
                 return javaCodeBuilder;
             } else {
                 throw new WasmException( "Abstract or native method can not be used: " + new FunctionName( method ).signatureName, -1 );

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

@@ -147,10 +147,12 @@ public abstract class WasmCodeBuilder {
      * 
      * @param variableTable
      *            variable table of the Java method.
+     * @param method
+     *            the method with signature as fallback for a missing variable table
      */
-    protected void reset( LocalVariableTable variableTable ) {
+    protected void reset( LocalVariableTable variableTable, MethodInfo method ) {
         instructions.clear();
-        localVariables.reset( variableTable );
+        localVariables.reset( variableTable, method );
     }
 
     /**

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

@@ -56,7 +56,7 @@ class WatCodeSyntheticFunctionName extends SyntheticFunctionName {
      */
     @Override
     protected WasmCodeBuilder getCodeBuilder( WatParser watParser ) {
-        watParser.parse( code, -1 );
+        watParser.parse( code, null, -1 );
         return watParser;
     }
 }

src/de/inetsoftware/jwebassembly/watparser/WatParser.java

@@ -23,6 +23,7 @@ import javax.annotation.Nonnegative;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import de.inetsoftware.classparser.MethodInfo;
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.module.ValueTypeConvertion;
 import de.inetsoftware.jwebassembly.module.WasmCodeBuilder;
@@ -44,10 +45,12 @@ public class WatParser extends WasmCodeBuilder {
      *            the text format content of a function
      * @param lineNumber
      *            the line number for an error message
+     * @param method
+     *            the method with signature as fallback for a missing variable table
      */
-    public void parse( String wat, int lineNumber ) {
+    public void parse( String wat, MethodInfo method, int lineNumber ) {
         try {
-            reset( null );
+            reset( null, method );
 
             List<String> tokens = splitTokens( wat );
             for( int i = 0; i < tokens.size(); i++ ) {

test/de/inetsoftware/jwebassembly/module/WatParserTest.java

@@ -41,7 +41,7 @@ public class WatParserTest {
         WatParser parser = new WatParser();
         WasmCodeBuilder codeBuilder = parser;
         codeBuilder.init( null, null, options );
-        parser.parse( wat, 100 );
+        parser.parse( wat, null, 100 );
         StringBuilder builder = new StringBuilder();
         ModuleWriter writer = new TextModuleWriter( new WasmTarget( builder ), options );
         writer.writeMethodStart( new FunctionName( "A.a()V" ), null );