improve exception message

src/de/inetsoftware/jwebassembly/WasmException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Volker Berlin (i-net software)
+ * Copyright 2017 - 2018 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.
@@ -27,6 +27,8 @@ public class WasmException extends RuntimeException {
 
     private String sourceFile;
 
+    private String className;
+
     /**
      * Create a new instance.
      * 
@@ -34,10 +36,12 @@ public class WasmException extends RuntimeException {
      *            the error message
      * @param sourceFile
      *            the sourceFile of the Java code
+     * @param className
+     *            the class name of the Java code
      * @param lineNumber
      *            the line number in Java Code
      */
-    public WasmException( String message, String sourceFile, int lineNumber ) {
+    public WasmException( String message, String sourceFile, String className, int lineNumber ) {
         super( message );
         this.sourceFile = sourceFile;
         this.lineNumber = lineNumber;
@@ -60,16 +64,21 @@ public class WasmException extends RuntimeException {
      * @param cause
      *            the wrapped cause
      * @param sourceFile
-     *            the sourceFile of the Java code
+     *            the source file of the Java code
+     * @param className
+     *            the class name of the Java code
      * @param lineNumber
      *            the line number in Java Code
      * @return a new instance
      */
-    public static WasmException create( Throwable cause, String sourceFile, int lineNumber ) {
+    public static WasmException create( Throwable cause, String sourceFile, String className, int lineNumber ) {
         WasmException wasmEx = create( cause );
         if( wasmEx.sourceFile == null ) {
             wasmEx.sourceFile = sourceFile;
         }
+        if( wasmEx.className == null ) {
+            wasmEx.className = className;
+        }
         if( wasmEx.lineNumber < 0 ) {
             wasmEx.lineNumber = lineNumber;
         }
@@ -103,13 +112,19 @@ public class WasmException extends RuntimeException {
      * {@inheritDoc}
      */
     @Override
-    public String toString() {
+    public String getMessage() {
-        String str = super.toString();
+        String str = super.getMessage();
-        if( sourceFile != null || lineNumber > 0 ) {
+        if( sourceFile != null || className != null || lineNumber >= 0 ) {
-            str += " at " + (sourceFile != null ? sourceFile : "line");
+            str += "\n\tat ";
+            if( className != null ) {
+                str += className.replace( '/', '.' ).replace( '$', '.' );
+            }
+            str += "(";
+            str += (sourceFile != null ? sourceFile : "line");
             if( lineNumber > 0 ) {
                 str += ":" + lineNumber;
             }
+            str += ")";
         }
         return str;
     }

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

@@ -693,7 +693,7 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
             if( entry != null ) {
                 id = entry.id;
             } else {
-                throw new WasmException( "Call to unknown function: " + name, null, -1 );
+                throw new WasmException( "Call to unknown function: " + name, null, null, -1 );
             }
         }
         codeStream.writeOpCode( CALL );

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

@@ -142,7 +142,7 @@ class BranchManger {
                         loop.endPosition = parsedBlock.startPosition + 3;
                         break;
                     default:
-                        throw new WasmException( "Unimplemented loop code operation: " + parsedBlock.op, null, parsedBlock.lineNumber );
+                        throw new WasmException( "Unimplemented loop code operation: " + parsedBlock.op, null, null, parsedBlock.lineNumber );
                 }
             } else {
                 switch ( parsedBlock.op ) {
@@ -225,7 +225,7 @@ class BranchManger {
                     calculateLoop( parent, parsedBlock, parsedOperations );
                     break;
                 default:
-                    throw new WasmException( "Unimplemented block code operation: " + parsedBlock.op, null, parsedBlock.lineNumber );
+                    throw new WasmException( "Unimplemented block code operation: " + parsedBlock.op, null, null, parsedBlock.lineNumber );
             }
         }
     }
@@ -538,7 +538,7 @@ class BranchManger {
                 deep++;
             }
         }
-        throw new WasmException( "GOTO code without target loop/block", null, gotoBlock.lineNumber );
+        throw new WasmException( "GOTO code without target loop/block", null, null, gotoBlock.lineNumber );
 
     }
 
@@ -658,7 +658,7 @@ class BranchManger {
                     newOp = NumericOperator.lt;
                     break;
                 default:
-                    throw new WasmException( "Not a compare operation: " + instr.numOp, null, lineNumber );
+                    throw new WasmException( "Not a compare operation: " + instr.numOp, null, null, lineNumber );
             }
             instr.numOp = newOp;
         }

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

@@ -78,7 +78,7 @@ class LocaleVariableManager {
         LocaleVariable var = variables[slot];
         if( var.valueType != null && var.valueType != valueType ) {
             throw new WasmException( "Redefine local variable type from " + var.valueType + " to "
-                            + valueType, null, -1 );
+                            + valueType, null, null, -1 );
         }
         var.valueType = valueType;
     }

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

@@ -48,6 +48,8 @@ public class ModuleGenerator {
 
     private String                      sourceFile;
 
+    private String                      className;
+
     private final List<WasmInstruction> instructions   = new ArrayList<>();
 
     private BranchManger                branchManager  = new BranchManger( instructions );
@@ -96,11 +98,10 @@ public class ModuleGenerator {
 
     private void iterateMethods( ClassFile classFile, Consumer<MethodInfo> handler ) throws WasmException {
         sourceFile = null; // clear previous value for the case an IO exception occur
+        className = null;
         try {
             sourceFile = classFile.getSourceFile();
-            if( sourceFile == null ) {
+            className = classFile.getThisClass().getName();
-                sourceFile = classFile.getThisClass().getName();
-            }
             MethodInfo[] methods = classFile.getMethods();
             for( MethodInfo method : methods ) {
                 Code code = method.getCode();
@@ -111,7 +112,7 @@ public class ModuleGenerator {
                 handler.accept( method );
             }
         } catch( IOException ioex ) {
-            throw WasmException.create( ioex, sourceFile, -1 );
+            throw WasmException.create( ioex, sourceFile, className, -1 );
         }
     }
 
@@ -136,7 +137,7 @@ public class ModuleGenerator {
                 writer.prepareFunction( name );
             }
         } catch( Exception ioex ) {
-            throw WasmException.create( ioex, sourceFile, -1 );
+            throw WasmException.create( ioex, sourceFile, className, -1 );
         }
     }
 
@@ -172,7 +173,7 @@ public class ModuleGenerator {
             }
         } catch( Exception ioex ) {
             int lineNumber = byteCode == null ? -1 : byteCode.getLineNumber();
-            throw WasmException.create( ioex, sourceFile, lineNumber );
+            throw WasmException.create( ioex, sourceFile, className, lineNumber );
         }
     }
 
@@ -411,7 +412,7 @@ public class ModuleGenerator {
                     case 94: // dup2_x2
                     case 95: // swap
                         // can be do with functions with more as one return value in future WASM standard
-                        throw new WasmException( "Stack duplicate is not supported in current WASM. try to save immediate values in a local variable: " + op, sourceFile, byteCode.getLineNumber() );
+                        throw new WasmException( "Stack duplicate is not supported in current WASM. try to save immediate values in a local variable: " + op, sourceFile, className, byteCode.getLineNumber() );
                     case 96: // iadd
                         instr = new WasmNumericInstruction( NumericOperator.add, ValueType.i32, codePos);
                         break;
@@ -469,7 +470,7 @@ public class ModuleGenerator {
                     case 114: // frem
                     case 115: // drem
                         //TODO can be implemented with a helper function like: (a - (long)(a / b) * (double)b) 
-                        throw new WasmException( "Modulo/Remainder for floating numbers is not supported in WASM. Use int or long data types." + op, sourceFile, byteCode.getLineNumber() );
+                        throw new WasmException( "Modulo/Remainder for floating numbers is not supported in WASM. Use int or long data types." + op, sourceFile, className, byteCode.getLineNumber() );
                     case 116: // ineg
                         instructions.add( new WasmConstInstruction( -1, ValueType.i32, codePos ) );
                         instr = new WasmNumericInstruction( NumericOperator.mul, ValueType.i32, codePos );
@@ -698,7 +699,7 @@ public class ModuleGenerator {
                     //TODO case 200: // goto_w
                     //TODO case 201: // jsr_w
                     default:
-                        throw new WasmException( "Unimplemented Java byte code operation: " + op, sourceFile, byteCode.getLineNumber() );
+                        throw new WasmException( "Unimplemented Java byte code operation: " + op, sourceFile, className, byteCode.getLineNumber() );
                 }
                 if( instr != null ) {
                     instructions.add( instr );
@@ -715,7 +716,7 @@ public class ModuleGenerator {
         } catch( WasmException ex ) {
             throw ex;
         } catch( Exception ex ) {
-            throw WasmException.create( ex, sourceFile, byteCode.getLineNumber() );
+            throw WasmException.create( ex, sourceFile, className, byteCode.getLineNumber() );
         }
     }
 
@@ -819,7 +820,7 @@ public class ModuleGenerator {
                 return instr.getCodePosition();
             }
         }
-        throw new WasmException( "Switch start position not found", sourceFile, -1 ); // should never occur
+        throw new WasmException( "Switch start position not found", sourceFile, className, -1 ); // should never occur
     }
 
     /**
@@ -939,7 +940,7 @@ public class ModuleGenerator {
                 numOp = NumericOperator.le;
                 break;
             default:
-                throw new WasmException( "Unexpected compare sub operation: " + nextOp, null, -1 );
+                throw new WasmException( "Unexpected compare sub operation: " + nextOp, sourceFile, className, -1 );
         }
         int offset = byteCode.readShort();
         WasmNumericInstruction compare = new WasmNumericInstruction( numOp, valueType, codePos );

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

@@ -87,7 +87,7 @@ public enum ValueType {
             default:
                 javaType = javaSignature.substring( idx, idx + 1 );
         }
-        throw new WasmException( "Not supported Java data type in method signature: " + javaType, null, -1 );
+        throw new WasmException( "Not supported Java data type in method signature: " + javaType, null, null, -1 );
     }
 
 }

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

@@ -81,7 +81,7 @@ class WasmConstInstruction extends WasmInstruction {
         } else if( clazz == Double.class ) {
             return ValueType.f64;
         } else {
-            throw new WasmException( "Not supported constant type: " + clazz, null, -1 );
+            throw new WasmException( "Not supported constant type: " + clazz, null, null, -1 );
         }
 
     }