decompiler: track lines in anonymous classes as well

10 years ago · 46c36636bc
parent 7bb0f5ba7e
commit 46c36636bc
29 changed files with 287 additions and 196 deletions
--- a/src/org/jetbrains/java/decompiler/main/ClassWriter.java
+++ b/src/org/jetbrains/java/decompiler/main/ClassWriter.java
@ -814,7 +814,7 @@ public class ClassWriter {
          try {
            tracer.incrementCurrentSourceLine(buffer.count(lineSeparator, start_index_method));

-            String code = root.toJava(indent + 1, tracer);
+            TextBuffer code = root.toJava(indent + 1, tracer);

            hideMethod = (clinit || dinit || hideConstructor(wrapper, init, throwsExceptions, paramCount)) && code.length() == 0;

--- a/src/org/jetbrains/java/decompiler/main/TextBuffer.java
+++ b/src/org/jetbrains/java/decompiler/main/TextBuffer.java
@ -17,10 +17,7 @@ package org.jetbrains.java.decompiler.main;

 import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;

-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;

 /**
 * Allows to connect text with resulting lines
@ -32,7 +29,6 @@ public class TextBuffer {
  private final String myIndent = (String)DecompilerContext.getProperty(IFernflowerPreferences.INDENT_STRING);
  private final StringBuilder myStringBuilder;
  private Map<Integer, Integer> myLineToOffsetMapping = null;
-  private boolean myTrackLines = true;

  public TextBuffer() {
    myStringBuilder = new StringBuilder();
@ -42,12 +38,12 @@ public class TextBuffer {
    myStringBuilder = new StringBuilder(size);
  }

-  public void setTrackLines(boolean trackLines) {
-    myTrackLines = false;
+  public TextBuffer(String text) {
+    myStringBuilder = new StringBuilder(text);
  }

  public void setCurrentLine(int line) {
-    if (myTrackLines && line >= 0) {
+    if (line >= 0) {
      checkMapCreated();
      myLineToOffsetMapping.put(line, myStringBuilder.length()+1);
    }
@ -75,6 +71,26 @@ public class TextBuffer {
    return this;
  }

+  public TextBuffer prepend(String s) {
+    insert(0, s);
+    return this;
+  }
+
+  public TextBuffer enclose(String left, String right) {
+    prepend(left);
+    append(right);
+    return this;
+  }
+
+  public boolean containsOnlyWhitespaces() {
+    for (int i = 0; i < myStringBuilder.length(); i++) {
+      if (myStringBuilder.charAt(i) != ' ') {
+        return false;
+      }
+    }
+    return true;
+  }
+
  @Override
  public String toString() {
    String original = myStringBuilder.toString();
@ -117,9 +133,10 @@ public class TextBuffer {

  private void appendLines(StringBuilder res, String[] srcLines, int from, int to, int requiredLineNumber) {
    if (to - from > requiredLineNumber) {
+      List<String> strings = compactLines(Arrays.asList(srcLines).subList(from, to) ,requiredLineNumber);
      int separatorsRequired = requiredLineNumber - 1;
-      for (int i = from; i < to; i++) {
-        res.append(srcLines[i]);
+      for (String s : strings) {
+        res.append(s);
        if (separatorsRequired-- > 0) {
          res.append(myLineSeparator);
        }
@ -144,8 +161,23 @@ public class TextBuffer {
    return myStringBuilder.substring(start);
  }

+  public TextBuffer setStart(int position) {
+    myStringBuilder.delete(0, position);
+    shiftMapping(0, -position);
+    return this;
+  }
+
  public void setLength(int position) {
    myStringBuilder.setLength(position);
+    if (myLineToOffsetMapping != null) {
+      HashMap<Integer, Integer> newMap = new HashMap<Integer, Integer>();
+      for (Map.Entry<Integer, Integer> entry : myLineToOffsetMapping.entrySet()) {
+        if (entry.getValue() <= position) {
+          newMap.put(entry.getKey(), entry.getValue());
+        }
+      }
+      myLineToOffsetMapping = newMap;
+    }
  }

  public TextBuffer append(TextBuffer buffer) {
@ -161,11 +193,17 @@ public class TextBuffer {

  private void shiftMapping(int startOffset, int shiftOffset) {
    if (myLineToOffsetMapping != null) {
+      HashMap<Integer, Integer> newMap = new HashMap<Integer, Integer>();
      for (Map.Entry<Integer, Integer> entry : myLineToOffsetMapping.entrySet()) {
-        if (entry.getValue() >= startOffset) {
-          myLineToOffsetMapping.put(entry.getKey(), entry.getValue() + shiftOffset);
+        int newValue = entry.getValue();
+        if (newValue >= startOffset) {
+          newValue += shiftOffset;
+        }
+        if (newValue >= 0) {
+          newMap.put(entry.getKey(), newValue);
        }
      }
+      myLineToOffsetMapping = newMap;
    }
  }

@ -189,4 +227,34 @@ public class TextBuffer {
    }
    return count;
  }
+
+  private static List<String> compactLines(List<String> srcLines, int requiredLineNumber) {
+    if (srcLines.size() < 2 || srcLines.size() <= requiredLineNumber) {
+      return srcLines;
+    }
+    List<String> res = new LinkedList<String>(srcLines);
+    // first join lines with a single { or }
+    for (int i = res.size()-1; i > 0 ; i--) {
+      String s = res.get(i);
+      if (s.trim().equals("{") || s.trim().equals("}")) {
+        res.set(i-1, res.get(i-1).concat(s));
+        res.remove(i);
+      }
+      if (res.size() <= requiredLineNumber) {
+        return res;
+      }
+    }
+    // now join empty lines
+    for (int i = res.size()-1; i > 0 ; i--) {
+      String s = res.get(i);
+      if (s.trim().isEmpty()) {
+        res.set(i-1, res.get(i-1).concat(s));
+        res.remove(i);
+      }
+      if (res.size() <= requiredLineNumber) {
+        return res;
+      }
+    }
+    return res;
+  }
 }
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/ExprProcessor.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/ExprProcessor.java
@ -756,8 +756,8 @@ public class ExprProcessor implements CodeConstants {
               .isClassdef()));
  }

-  public static String jmpWrapper(Statement stat, int indent, boolean semicolon, BytecodeMappingTracer tracer) {
-    StringBuilder buf = new StringBuilder(stat.toJava(indent, tracer));
+  public static TextBuffer jmpWrapper(Statement stat, int indent, boolean semicolon, BytecodeMappingTracer tracer) {
+    TextBuffer buf = stat.toJava(indent, tracer);

    String new_line_separator = DecompilerContext.getNewLineSeparator();

@ -776,7 +776,7 @@ public class ExprProcessor implements CodeConstants {
        }

        if (edge.labeled) {
-          buf.append(" label").append(edge.closure.id);
+          buf.append(" label").append(edge.closure.id.toString());
        }
        buf.append(";").append(new_line_separator);
        tracer.incrementCurrentSourceLine();
@ -788,7 +788,7 @@ public class ExprProcessor implements CodeConstants {
      tracer.incrementCurrentSourceLine();
    }

-    return buf.toString();
+    return buf;
  }

  public static String buildJavaClassName(String name) {
@ -805,18 +805,18 @@ public class ExprProcessor implements CodeConstants {
    return res;
  }

-  public static String listToJava(List<Exprent> lst, int indent, BytecodeMappingTracer tracer) {
+  public static TextBuffer listToJava(List<Exprent> lst, int indent, BytecodeMappingTracer tracer) {
    if (lst == null || lst.isEmpty()) {
-      return "";
+      return new TextBuffer();
    }

    String indstr = InterpreterUtil.getIndentString(indent);
    String new_line_separator = DecompilerContext.getNewLineSeparator();

-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    for (Exprent expr : lst) {
-      String content = expr.toJava(indent, tracer);
+      TextBuffer content = expr.toJava(indent, tracer);
      if (content.length() > 0) {
        if (expr.type != Exprent.EXPRENT_VAR || !((VarExprent)expr).isClassdef()) {
          buf.append(indstr);
@ -833,7 +833,7 @@ public class ExprProcessor implements CodeConstants {
      }
    }

-    return buf.toString();
+    return buf;
  }

  public static ConstExprent getDefaultArrayValue(VarType arrtype) {
@ -873,7 +873,7 @@ public class ExprProcessor implements CodeConstants {
    boolean ret = false;
    VarType rightType = exprent.getExprType();

-    String res = exprent.toJava(indent, tracer);
+    TextBuffer res = exprent.toJava(indent, tracer);

    boolean cast =
      !leftType.isSuperset(rightType) && (rightType.equals(VarType.VARTYPE_OBJECT) || leftType.type != CodeConstants.TYPE_OBJECT);
@ -889,10 +889,10 @@ public class ExprProcessor implements CodeConstants {

    if (cast) {
      if (exprent.getPrecedence() >= FunctionExprent.getPrecedence(FunctionExprent.FUNCTION_CAST)) {
-        res = "(" + res + ")";
+        res.enclose("(", ")");
      }

-      res = "(" + getCastTypeName(leftType) + ")" + res;
+      res.prepend("(" + getCastTypeName(leftType) + ")");
      ret = true;
    }

--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
@ -47,11 +48,11 @@ public class AnnotationExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

    String new_line_separator = DecompilerContext.getNewLineSeparator();

-    StringBuilder buffer = new StringBuilder();
+    TextBuffer buffer = new TextBuffer();
    String indstr = InterpreterUtil.getIndentString(indent);

    buffer.append(indstr);
@ -82,7 +83,7 @@ public class AnnotationExprent extends Exprent {
      buffer.append(")");
    }

-    return buffer.toString();
+    return buffer;
  }

  public int getAnnotationType() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ArrayExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ArrayExprent.java
@ -15,6 +15,7 @@
 */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
@ -81,11 +82,11 @@ public class ArrayExprent extends Exprent {


  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
-    String res = array.toJava(indent, tracer);
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
+    TextBuffer res = array.toJava(indent, tracer);

    if (array.getPrecedence() > getPrecedence()) { // array precedence equals 0
-      res = "(" + res + ")";
+      res.enclose("(", ")");
    }

    VarType arrtype = array.getExprType();
@ -93,12 +94,12 @@ public class ArrayExprent extends Exprent {
      VarType objarr = VarType.VARTYPE_OBJECT.copy();
      objarr.arraydim = 1; // type family does not change

-      res = "((" + ExprProcessor.getCastTypeName(objarr) + ")" + res + ")";
+      res.enclose("((" + ExprProcessor.getCastTypeName(objarr) + ")", ")");
    }

    tracer.addMapping(bytecode);

-    return res + "[" + index.toJava(indent, tracer) + "]";
+    return res.append("[").append(index.toJava(indent, tracer)).append("]");
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java
@ -17,6 +17,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import java.util.List;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;

 public class AssertExprent extends Exprent {
@ -32,9 +33,9 @@ public class AssertExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

-    StringBuilder buffer = new StringBuilder();
+    TextBuffer buffer = new TextBuffer();

    buffer.append("assert ");

@ -52,6 +53,6 @@ public class AssertExprent extends Exprent {
      buffer.append(parameters.get(1).toJava(indent, tracer));
    }

-    return buffer.toString();
+    return buffer;
  }
 }
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssignmentExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssignmentExprent.java
@ -17,6 +17,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
@ -105,7 +106,7 @@ public class AssignmentExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    VarType leftType = left.getExprType();
    VarType rightType = right.getExprType();

@ -127,10 +128,10 @@ public class AssignmentExprent extends Exprent {
    }

    if (hiddenField) {
-      return "";
+      return new TextBuffer();
    }

-    StringBuilder buffer = new StringBuilder();
+    TextBuffer buffer = new TextBuffer();

    if (fieldInClassInit) {
      buffer.append(((FieldExprent)left).getName());
@ -139,23 +140,23 @@ public class AssignmentExprent extends Exprent {
      buffer.append(left.toJava(indent, tracer));
    }

-    String res = right.toJava(indent, tracer);
+    TextBuffer res = right.toJava(indent, tracer);

    if (condtype == CONDITION_NONE &&
        !leftType.isSuperset(rightType) &&
        (rightType.equals(VarType.VARTYPE_OBJECT) || leftType.type != CodeConstants.TYPE_OBJECT)) {
      if (right.getPrecedence() >= FunctionExprent.getPrecedence(FunctionExprent.FUNCTION_CAST)) {
-        res = "(" + res + ")";
+        res.enclose("(", ")");
      }

-      res = "(" + ExprProcessor.getCastTypeName(leftType) + ")" + res;
+      res.prepend("(" + ExprProcessor.getCastTypeName(leftType) + ")");
    }

    buffer.append(condtype == CONDITION_NONE ? " = " : funceq[condtype]).append(res);

    tracer.addMapping(bytecode);

-    return buffer.toString();
+    return buffer;
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ConstExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ConstExprent.java
@ -17,6 +17,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
@ -108,19 +109,19 @@ public class ConstExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    boolean literal = DecompilerContext.getOption(IFernflowerPreferences.LITERALS_AS_IS);
    boolean ascii = DecompilerContext.getOption(IFernflowerPreferences.ASCII_STRING_CHARACTERS);

    tracer.addMapping(bytecode);

    if (consttype.type != CodeConstants.TYPE_NULL && value == null) {
-      return ExprProcessor.getCastTypeName(consttype);
+      return new TextBuffer(ExprProcessor.getCastTypeName(consttype));
    }
    else {
      switch (consttype.type) {
        case CodeConstants.TYPE_BOOLEAN:
-          return Boolean.toString(((Integer)value).intValue() != 0);
+          return new TextBuffer(Boolean.toString(((Integer)value).intValue() != 0));
        case CodeConstants.TYPE_CHAR:
          Integer val = (Integer)value;
          String ret = escapes.get(val);
@ -133,7 +134,7 @@ public class ConstExprent extends Exprent {
              ret = InterpreterUtil.charToUnicodeLiteral(c);
            }
          }
-          return "\'" + ret + "\'";
+          return new TextBuffer(ret).enclose("\'", "\'");
        case CodeConstants.TYPE_BYTE:
        case CodeConstants.TYPE_BYTECHAR:
        case CodeConstants.TYPE_SHORT:
@ -143,7 +144,7 @@ public class ConstExprent extends Exprent {

          String intfield;
          if (literal) {
-            return value.toString();
+            return new TextBuffer(value.toString());
          }
          else if (ival == Integer.MAX_VALUE) {
            intfield = "MAX_VALUE";
@ -152,7 +153,7 @@ public class ConstExprent extends Exprent {
            intfield = "MIN_VALUE";
          }
          else {
-            return value.toString();
+            return new TextBuffer(value.toString());
          }
          return new FieldExprent(intfield, "java/lang/Integer", true, null, FieldDescriptor.INTEGER_DESCRIPTOR).toJava(0, tracer);
        case CodeConstants.TYPE_LONG:
@ -160,7 +161,7 @@ public class ConstExprent extends Exprent {

          String longfield;
          if (literal) {
-            return value.toString() + "L";
+            return new TextBuffer(value.toString()).append("L");
          }
          else if (lval == Long.MAX_VALUE) {
            longfield = "MAX_VALUE";
@ -169,7 +170,7 @@ public class ConstExprent extends Exprent {
            longfield = "MIN_VALUE";
          }
          else {
-            return value.toString() + "L";
+            return new TextBuffer(value.toString()).append("L");
          }
          return new FieldExprent(longfield, "java/lang/Long", true, null, FieldDescriptor.LONG_DESCRIPTOR).toJava(0, tracer);
        case CodeConstants.TYPE_DOUBLE:
@ -178,16 +179,16 @@ public class ConstExprent extends Exprent {
          String doublefield;
          if (literal) {
            if (Double.isNaN(dval)) {
-              return "0.0D / 0.0";
+              return new TextBuffer("0.0D / 0.0");
            }
            else if (dval == Double.POSITIVE_INFINITY) {
-              return "1.0D / 0.0";
+              return new TextBuffer("1.0D / 0.0");
            }
            else if (dval == Double.NEGATIVE_INFINITY) {
-              return "-1.0D / 0.0";
+              return new TextBuffer("-1.0D / 0.0");
            }
            else {
-              return value.toString() + "D";
+              return new TextBuffer(value.toString()).append("D");
            }
          }
          else if (Double.isNaN(dval)) {
@ -206,7 +207,7 @@ public class ConstExprent extends Exprent {
            doublefield = "MIN_VALUE";
          }
          else {
-            return value.toString() + "D";
+            return new TextBuffer(value.toString()).append("D");
          }
          return new FieldExprent(doublefield, "java/lang/Double", true, null, FieldDescriptor.DOUBLE_DESCRIPTOR).toJava(0, tracer);
        case CodeConstants.TYPE_FLOAT:
@ -215,16 +216,16 @@ public class ConstExprent extends Exprent {
          String floatfield;
          if (literal) {
            if (Double.isNaN(fval)) {
-              return "0.0F / 0.0";
+              return new TextBuffer("0.0F / 0.0");
            }
            else if (fval == Double.POSITIVE_INFINITY) {
-              return "1.0F / 0.0";
+              return new TextBuffer("1.0F / 0.0");
            }
            else if (fval == Double.NEGATIVE_INFINITY) {
-              return "-1.0F / 0.0";
+              return new TextBuffer("-1.0F / 0.0");
            }
            else {
-              return value.toString() + "F";
+              return new TextBuffer(value.toString()).append("F");
            }
          }
          else if (Float.isNaN(fval)) {
@ -243,14 +244,14 @@ public class ConstExprent extends Exprent {
            floatfield = "MIN_VALUE";
          }
          else {
-            return value.toString() + "F";
+            return new TextBuffer(value.toString()).append("F");
          }
          return new FieldExprent(floatfield, "java/lang/Float", true, null, FieldDescriptor.FLOAT_DESCRIPTOR).toJava(0, tracer);
        case CodeConstants.TYPE_NULL:
-          return "null";
+          return new TextBuffer("null");
        case CodeConstants.TYPE_OBJECT:
          if (consttype.equals(VarType.VARTYPE_STRING)) {
-            return "\"" + convertStringToJava(value.toString(), ascii) + "\"";
+            return new TextBuffer(convertStringToJava(value.toString(), ascii)).enclose("\"", "\"");
          }
          else if (consttype.equals(VarType.VARTYPE_CLASS)) {
            String strval = value.toString();
@ -263,7 +264,7 @@ public class ConstExprent extends Exprent {
              classtype = new VarType(strval, true);
            }

-            return ExprProcessor.getCastTypeName(classtype) + ".class";
+            return new TextBuffer(ExprProcessor.getCastTypeName(classtype)).append(".class");
          }
      }
    }
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ExitExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/ExitExprent.java
@ -77,7 +77,7 @@ public class ExitExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

    tracer.addMapping(bytecode);

@ -89,7 +89,7 @@ public class ExitExprent extends Exprent {
        ExprProcessor.getCastedExprent(value, rettype, buffer, indent, false, tracer);
      }

-      return "return" + buffer.toString();
+      return buffer.prepend("return");
    }
    else {

@ -119,12 +119,12 @@ public class ExitExprent extends Exprent {
            TextBuffer buffer = new TextBuffer();
            ExprProcessor.getCastedExprent(value, exctype, buffer, indent, false, tracer);

-            return "throw " + buffer.toString();
+            return buffer.prepend("throw ");
          }
        }
      }

-      return "throw " + value.toJava(indent, tracer);
+      return value.toJava(indent, tracer).prepend("throw ");
    }
  }

--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/Exprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/Exprent.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
@ -128,7 +129,7 @@ public class Exprent {
    throw new RuntimeException("not implemented");
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    throw new RuntimeException("not implemented");
  }

--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/FieldExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/FieldExprent.java
@ -96,8 +96,8 @@ public class FieldExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
-    StringBuilder buf = new StringBuilder();
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
+    TextBuffer buf = new TextBuffer();


    if (isStatic) {
@ -162,7 +162,7 @@ public class FieldExprent extends Exprent {

    tracer.addMapping(bytecode);

-    return buf.toString();
+    return buf;
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/FunctionExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/FunctionExprent.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

 import org.jetbrains.java.decompiler.code.CodeConstants;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
@ -448,87 +449,87 @@ public class FunctionExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

    tracer.addMapping(bytecode);

    if (functype <= FUNCTION_USHR) {
-      return wrapOperandString(lstOperands.get(0), false, indent, tracer) + operators[functype] +
-             wrapOperandString(lstOperands.get(1), true, indent, tracer);
+      return wrapOperandString(lstOperands.get(0), false, indent, tracer)
+        .append(operators[functype])
+        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
    }

    if (functype >= FUNCTION_EQ) {
-      return wrapOperandString(lstOperands.get(0), false, indent, tracer) + operators[functype - FUNCTION_EQ + 11] +
-             wrapOperandString(lstOperands.get(1), true, indent, tracer);
+      return wrapOperandString(lstOperands.get(0), false, indent, tracer)
+        .append(operators[functype - FUNCTION_EQ + 11])
+        .append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
    }

    switch (functype) {
      case FUNCTION_BITNOT:
-        return "~" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("~");
      case FUNCTION_BOOLNOT:
-        return "!" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("!");
      case FUNCTION_NEG:
-        return "-" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("-");
      case FUNCTION_CAST:
-        return "(" + lstOperands.get(1).toJava(indent, tracer) + ")" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return lstOperands.get(1).toJava(indent, tracer).enclose("(", ")").append(wrapOperandString(lstOperands.get(0), true, indent, tracer));
      case FUNCTION_ARRAYLENGTH:
        Exprent arr = lstOperands.get(0);

-        String res = wrapOperandString(arr, false, indent, tracer);
+        TextBuffer res = wrapOperandString(arr, false, indent, tracer);
        if (arr.getExprType().arraydim == 0) {
          VarType objarr = VarType.VARTYPE_OBJECT.copy();
          objarr.arraydim = 1; // type family does not change

-          res = "((" + ExprProcessor.getCastTypeName(objarr) + ")" + res + ")";
+          res.enclose("((" + ExprProcessor.getCastTypeName(objarr) + ")", ")");
        }
-        return res + ".length";
+        return res.append(".length");
      case FUNCTION_IIF:
-        return wrapOperandString(lstOperands.get(0), true, indent, tracer) + "?" + wrapOperandString(lstOperands.get(1), true, indent, tracer) + ":" +
-               wrapOperandString(lstOperands.get(2), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer)
+          .append("?")
+          .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+          .append(":")
+          .append(wrapOperandString(lstOperands.get(2), true, indent, tracer));
      case FUNCTION_IPP:
-        return wrapOperandString(lstOperands.get(0), true, indent, tracer) + "++";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("++");
      case FUNCTION_PPI:
-        return "++" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("++");
      case FUNCTION_IMM:
-        return wrapOperandString(lstOperands.get(0), true, indent, tracer) + "--";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).append("--");
      case FUNCTION_MMI:
-        return "--" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("--");
      case FUNCTION_INSTANCEOF:
-        return wrapOperandString(lstOperands.get(0), true, indent, tracer) + " instanceof " + wrapOperandString(lstOperands.get(1), true, indent, tracer);
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).append(" instanceof ").append(wrapOperandString(lstOperands.get(1), true, indent, tracer));
      case FUNCTION_LCMP: // shouldn't appear in the final code
-        return "__lcmp__(" +
-               wrapOperandString(lstOperands.get(0), true, indent, tracer) +
-               "," +
-               wrapOperandString(lstOperands.get(1), true, indent, tracer) +
-               ")";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__lcmp__(")
+                 .append(",")
+                 .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+                 .append(")");
      case FUNCTION_FCMPL: // shouldn't appear in the final code
-        return "__fcmpl__(" +
-               wrapOperandString(lstOperands.get(0), true, indent, tracer) +
-               "," +
-               wrapOperandString(lstOperands.get(1), true, indent, tracer) +
-               ")";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpl__(")
+                 .append(",")
+                 .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+                 .append(")");
      case FUNCTION_FCMPG: // shouldn't appear in the final code
-        return "__fcmpg__(" +
-               wrapOperandString(lstOperands.get(0), true, indent, tracer) +
-               "," +
-               wrapOperandString(lstOperands.get(1), true, indent, tracer) +
-               ")";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__fcmpg__(")
+                 .append(",")
+                 .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+                 .append(")");
      case FUNCTION_DCMPL: // shouldn't appear in the final code
-        return "__dcmpl__(" +
-               wrapOperandString(lstOperands.get(0), true, indent, tracer) +
-               "," +
-               wrapOperandString(lstOperands.get(1), true, indent, tracer) +
-               ")";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpl__(")
+                 .append(",")
+                 .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+                 .append(")");
      case FUNCTION_DCMPG: // shouldn't appear in the final code
-        return "__dcmpg__(" +
-               wrapOperandString(lstOperands.get(0), true, indent, tracer) +
-               "," +
-               wrapOperandString(lstOperands.get(1), true, indent, tracer) +
-               ")";
+        return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("__dcmpg__(")
+                 .append(",")
+                 .append(wrapOperandString(lstOperands.get(1), true, indent, tracer))
+                 .append(")");
    }

    if (functype <= FUNCTION_I2S) {
-      return "(" + ExprProcessor.getTypeName(types[functype - FUNCTION_I2L]) + ")" + wrapOperandString(lstOperands.get(0), true, indent, tracer);
+      return wrapOperandString(lstOperands.get(0), true, indent, tracer).prepend("(" + ExprProcessor.getTypeName(types[functype - FUNCTION_I2L]) + ")");
    }

    //		return "<unknown function>";
@ -547,7 +548,7 @@ public class FunctionExprent extends Exprent {
    return types[functype - FUNCTION_I2L];
  }

-  private String wrapOperandString(Exprent expr, boolean eq, int indent, BytecodeMappingTracer tracer) {
+  private TextBuffer wrapOperandString(Exprent expr, boolean eq, int indent, BytecodeMappingTracer tracer) {

    int myprec = getPrecedence();
    int exprprec = expr.getPrecedence();
@ -563,10 +564,10 @@ public class FunctionExprent extends Exprent {
      }
    }

-    String res = expr.toJava(indent, tracer);
+    TextBuffer res = expr.toJava(indent, tracer);

    if (parentheses) {
-      res = "(" + res + ")";
+      res.enclose("(", ")");
    }

    return res;
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/IfExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/IfExprent.java
@ -15,6 +15,7 @@
 */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
@ -113,9 +114,9 @@ public class IfExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    tracer.addMapping(bytecode);
-    return "if(" + condition.toJava(indent, tracer) + ")";
+    return condition.toJava(indent, tracer).enclose("if(", ")");
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java
@ -189,8 +189,8 @@ public class InvocationExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
-    StringBuilder buf = new StringBuilder("");
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
+    TextBuffer buf = new TextBuffer();

    String super_qualifier = null;
    boolean isInstanceThis = false;
@ -276,7 +276,7 @@ public class InvocationExprent extends Exprent {
          buf.append("super");
        }
        else {
-          String res = instance.toJava(indent, tracer);
+          TextBuffer res = instance.toJava(indent, tracer);

          VarType rightType = instance.getExprType();
          VarType leftType = new VarType(CodeConstants.TYPE_OBJECT, 0, classname);
@ -285,7 +285,7 @@ public class InvocationExprent extends Exprent {
            buf.append("((").append(ExprProcessor.getCastTypeName(leftType)).append(")");

            if (instance.getPrecedence() >= FunctionExprent.getPrecedence(FunctionExprent.FUNCTION_CAST)) {
-              res = "(" + res + ")";
+              res.enclose("(", ")");
            }
            buf.append(res).append(")");
          }
@ -302,7 +302,7 @@ public class InvocationExprent extends Exprent {
    switch (functype) {
      case TYP_GENERAL:
        if (VarExprent.VAR_NAMELESS_ENCLOSURE.equals(buf.toString())) {
-          buf = new StringBuilder("");
+          buf = new TextBuffer();
        }

        if (buf.length() > 0) {
@ -370,7 +370,7 @@ public class InvocationExprent extends Exprent {
    }
    buf.append(")");

-    return buf.toString();
+    return buf;
  }

  private Set<Integer> getAmbiguousParameters() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/MonitorExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/MonitorExprent.java
@ -15,6 +15,7 @@
 */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;

@ -51,15 +52,15 @@ public class MonitorExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

    tracer.addMapping(bytecode);

    if (montype == MONITOR_ENTER) {
-      return "synchronized(" + value.toJava(indent, tracer) + ")";
+      return value.toJava(indent, tracer).enclose("synchronized(", ")");
    }
    else {
-      return "";
+      return new TextBuffer();
    }
  }

--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/NewExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/NewExprent.java
@ -172,7 +172,7 @@ public class NewExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    TextBuffer buf = new TextBuffer();

    if (anonymous) {
@ -247,10 +247,10 @@ public class NewExprent extends Exprent {
            typename = typename.substring(typename.lastIndexOf('.') + 1);
          }
        }
-        buf.insert(0, "new " + typename);
+        buf.prepend("new " + typename);

        if (enclosing != null) {
-          buf.insert(0, enclosing + ".");
+          buf.prepend(enclosing + ".");
        }
      }

@ -268,10 +268,7 @@ public class NewExprent extends Exprent {
        new ClassWriter().classLambdaToJava(child, buf, methodObject, indent);
      }
      else {
-        // do not track lines in sub classes for now
-        buf.setTrackLines(false);
        new ClassWriter().classToJava(child, buf, indent);
-        buf.setTrackLines(true);
      }
    }
    else if (directArrayInit) {
@ -349,10 +346,10 @@ public class NewExprent extends Exprent {
              typename = typename.substring(typename.lastIndexOf('.') + 1);
            }
          }
-          buf.insert(0, "new " + typename);
+          buf.prepend("new " + typename);

          if (enclosing != null) {
-            buf.insert(0, enclosing + ".");
+            buf.prepend(enclosing + ".");
          }
        }
      }
@ -361,7 +358,11 @@ public class NewExprent extends Exprent {

        if (lstArrayElements.isEmpty()) {
          for (int i = 0; i < newtype.arraydim; i++) {
-            buf.append("[").append(i < lstDims.size() ? lstDims.get(i).toJava(indent, tracer) : "").append("]");
+            buf.append("[");
+            if (i < lstDims.size()) {
+              buf.append(lstDims.get(i).toJava(indent, tracer));
+            }
+            buf.append("]");
          }
        }
        else {
@ -386,7 +387,7 @@ public class NewExprent extends Exprent {
        }
      }
    }
-    return buf.toString();
+    return buf;
  }

  private static String getQualifiedNewInstance(String classname, List<Exprent> lstParams, int indent, BytecodeMappingTracer tracer) {
@ -414,7 +415,7 @@ public class NewExprent extends Exprent {
        }

        if (isQualifiedNew) {
-          return enclosing.toJava(indent, tracer);
+          return enclosing.toJava(indent, tracer).toString();
        }
      }
    }
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/SwitchExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/SwitchExprent.java
@ -15,6 +15,7 @@
 */
 package org.jetbrains.java.decompiler.modules.decompiler.exps;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
@ -83,9 +84,9 @@ public class SwitchExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    tracer.addMapping(bytecode);
-    return "switch(" + value.toJava(indent, tracer) + ")";
+    return value.toJava(indent, tracer).enclose("switch(", ")");
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/VarExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/VarExprent.java
@ -83,7 +83,7 @@ public class VarExprent extends Exprent {
  }

  @Override
-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    TextBuffer buffer = new TextBuffer();

    tracer.addMapping(bytecode);
@ -107,7 +107,7 @@ public class VarExprent extends Exprent {
      buffer.append(name == null ? ("var" + index + (version == 0 ? "" : "_" + version)) : name);
    }

-    return buffer.toString();
+    return buffer;
  }

  public boolean equals(Object o) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/BasicBlockStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/BasicBlockStatement.java
@ -20,6 +20,7 @@ import org.jetbrains.java.decompiler.code.Instruction;
 import org.jetbrains.java.decompiler.code.SimpleInstructionSequence;
 import org.jetbrains.java.decompiler.code.cfg.BasicBlock;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
@ -66,9 +67,8 @@ public class BasicBlockStatement extends Statement {
  // public methods
  // *****************************************************************************

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
-    return ExprProcessor.listToJava(varDefinitions, indent, tracer) +
-           ExprProcessor.listToJava(exprents, indent, tracer);
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
+    return ExprProcessor.listToJava(varDefinitions, indent, tracer).append(ExprProcessor.listToJava(exprents, indent, tracer));
  }

  public Statement getSimpleCopy() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/CatchAllStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/CatchAllStatement.java
@ -17,6 +17,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.DecHelper;
@ -111,28 +112,27 @@ public class CatchAllStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);
    String indstr1 = null;

    String new_line_separator = DecompilerContext.getNewLineSeparator();

-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    buf.append(ExprProcessor.listToJava(varDefinitions, indent, tracer));

    boolean labeled = isLabeled();
    if (labeled) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

    List<StatEdge> lstSuccs = first.getSuccessorEdges(STATEDGE_DIRECT_ALL);
    if (first.type == TYPE_TRYCATCH && first.varDefinitions.isEmpty() && isFinally &&
        !labeled && !first.isLabeled() && (lstSuccs.isEmpty() || !lstSuccs.get(0).explicit)) {
-      String content = ExprProcessor.jmpWrapper(first, indent, true, tracer);
-      content = content.substring(0, content.length() - new_line_separator.length());
-
+      TextBuffer content = ExprProcessor.jmpWrapper(first, indent, true, tracer);
+      content.setStart(content.length() - new_line_separator.length());
      buf.append(content);
    }
    else {
@ -162,7 +162,7 @@ public class CatchAllStatement extends Statement {
    buf.append(indstr).append("}").append(new_line_separator);
    tracer.incrementCurrentSourceLine();

-    return buf.toString();
+    return buf;
  }

  public void replaceStatement(Statement oldstat, Statement newstat) {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/CatchStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/CatchStatement.java
@ -17,6 +17,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.DecHelper;
@ -150,16 +151,16 @@ public class CatchStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);
-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    String new_line_separator = DecompilerContext.getNewLineSeparator();

    buf.append(ExprProcessor.listToJava(varDefinitions, indent, tracer));

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -191,7 +192,7 @@ public class CatchStatement extends Statement {
    buf.append(new_line_separator);

    tracer.incrementCurrentSourceLine();
-    return buf.toString();
+    return buf;
  }

  public Statement getSimpleCopy() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/DoStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/DoStatement.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.StatEdge;
@ -92,16 +93,16 @@ public class DoStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);
-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    String new_line_separator = DecompilerContext.getNewLineSeparator();

    buf.append(ExprProcessor.listToJava(varDefinitions, indent, tracer));

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -128,7 +129,11 @@ public class DoStatement extends Statement {
        tracer.incrementCurrentSourceLine();
        break;
      case LOOP_FOR:
-        buf.append(indstr).append("for(").append(initExprent.get(0) == null ? "" : initExprent.get(0).toJava(indent, tracer)).append("; ")
+        buf.append(indstr).append("for(");
+        if (initExprent.get(0) != null) {
+          buf.append(initExprent.get(0).toJava(indent, tracer));
+        }
+        buf.append("; ")
          .append(conditionExprent.get(0).toJava(indent, tracer)).append("; ").append(incExprent.get(0).toJava(indent, tracer)).append(") {")
          .append(new_line_separator);
        tracer.incrementCurrentSourceLine();
@ -137,7 +142,7 @@ public class DoStatement extends Statement {
        tracer.incrementCurrentSourceLine();
    }

-    return buf.toString();
+    return buf;
  }

  public List<Object> getSequentialObjects() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;

@ -54,14 +55,14 @@ public class GeneralStatement extends Statement {
  // public methods
  // *****************************************************************************

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);
-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    String new_line_separator = DecompilerContext.getNewLineSeparator();

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
    }

    buf.append(indstr).append("abstract statement {").append(new_line_separator);
@ -70,6 +71,6 @@ public class GeneralStatement extends Statement {
    }
    buf.append(indstr).append("}");

-    return buf.toString();
+    return buf;
  }
 }
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/IfStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/IfStatement.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.DecHelper;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
@ -200,9 +201,9 @@ public class IfStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);
-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    String new_line_separator = DecompilerContext.getNewLineSeparator();

@ -210,7 +211,7 @@ public class IfStatement extends Statement {
    buf.append(first.toJava(indent, tracer));

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -231,7 +232,7 @@ public class IfStatement extends Statement {
        }

        if (ifedge.labeled) {
-          buf.append(" label").append(ifedge.closure.id);
+          buf.append(" label").append(ifedge.closure.id.toString());
        }
      }
      buf.append(";").append(new_line_separator);
@ -249,8 +250,8 @@ public class IfStatement extends Statement {
          !elsestat.isLabeled() &&
          (elsestat.getSuccessorEdges(STATEDGE_DIRECT_ALL).isEmpty()
           || !elsestat.getSuccessorEdges(STATEDGE_DIRECT_ALL).get(0).explicit)) { // else if
-        String content = ExprProcessor.jmpWrapper(elsestat, indent, false, tracer);
-        content = content.substring(indstr.length());
+        TextBuffer content = ExprProcessor.jmpWrapper(elsestat, indent, false, tracer);
+        content.setStart(indstr.length());

        buf.append(indstr).append("} else ");
        buf.append(content);
@ -259,7 +260,7 @@ public class IfStatement extends Statement {
      }
      else {
        BytecodeMappingTracer else_tracer = new BytecodeMappingTracer(tracer.getCurrentSourceLine());
-        String content = ExprProcessor.jmpWrapper(elsestat, indent + 1, false, else_tracer);
+        TextBuffer content = ExprProcessor.jmpWrapper(elsestat, indent + 1, false, else_tracer);

        if (content.length() > 0) {
          buf.append(indstr).append("} else {").append(new_line_separator);
@ -278,7 +279,7 @@ public class IfStatement extends Statement {
      tracer.incrementCurrentSourceLine();
    }

-    return buf.toString();
+    return buf;
  }

  public void initExprents() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/RootStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/RootStatement.java
@ -15,6 +15,7 @@
 */
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;

@ -34,9 +35,8 @@ public class RootStatement extends Statement {
    first.setParent(this);
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
-    return ExprProcessor.listToJava(varDefinitions, indent, tracer) +
-           first.toJava(indent, tracer);
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
+    return ExprProcessor.listToJava(varDefinitions, indent, tracer).append(first.toJava(indent, tracer));
  }

  public Statement getDummyExit() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.DecHelper;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
@ -99,9 +100,9 @@ public class SequenceStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();

    String indstr = null;
    boolean islabeled = isLabeled();
@ -113,7 +114,7 @@ public class SequenceStatement extends Statement {
    if (islabeled) {
      indstr = InterpreterUtil.getIndentString(indent);
      indent++;
-      buf.append(indstr).append("label").append(this.id).append(": {").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(": {").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -128,10 +129,10 @@ public class SequenceStatement extends Statement {
        tracer.incrementCurrentSourceLine();
      }

-      String str = ExprProcessor.jmpWrapper(st, indent, false, tracer);
+      TextBuffer str = ExprProcessor.jmpWrapper(st, indent, false, tracer);
      buf.append(str);

-      notempty = (str.trim().length() > 0);
+      notempty = !str.containsOnlyWhitespaces();
    }

    if (islabeled) {
@ -139,7 +140,7 @@ public class SequenceStatement extends Statement {
      tracer.incrementCurrentSourceLine();
    }

-    return buf.toString();
+    return buf;
  }

  public Statement getSimpleCopy() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/Statement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/Statement.java
@ -18,6 +18,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.stats;
 import org.jetbrains.java.decompiler.code.CodeConstants;
 import org.jetbrains.java.decompiler.code.InstructionSequence;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.StatEdge;
@ -489,11 +490,11 @@ public class Statement {
  }

  // to be overwritten
-  public String toJava() {
+  public TextBuffer toJava() {
    return toJava(0, new BytecodeMappingTracer());
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    throw new RuntimeException("not implemented");
  }

--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SwitchStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SwitchStatement.java
@ -18,6 +18,7 @@ package org.jetbrains.java.decompiler.modules.decompiler.stats;
 import org.jetbrains.java.decompiler.code.SwitchInstruction;
 import org.jetbrains.java.decompiler.code.cfg.BasicBlock;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.main.collectors.CounterContainer;
 import org.jetbrains.java.decompiler.modules.decompiler.DecHelper;
@ -107,18 +108,18 @@ public class SwitchStatement extends Statement {
    return null;
  }

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {

    String indstr = InterpreterUtil.getIndentString(indent);

    String new_line_separator = DecompilerContext.getNewLineSeparator();

-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();
    buf.append(ExprProcessor.listToJava(varDefinitions, indent, tracer));
    buf.append(first.toJava(indent, tracer));

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -153,7 +154,7 @@ public class SwitchStatement extends Statement {
    buf.append(indstr).append("}").append(new_line_separator);
    tracer.incrementCurrentSourceLine();

-    return buf.toString();
+    return buf;
  }

  public void initExprents() {
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SynchronizedStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SynchronizedStatement.java
@ -16,6 +16,7 @@
 package org.jetbrains.java.decompiler.modules.decompiler.stats;

 import org.jetbrains.java.decompiler.main.DecompilerContext;
+import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.SequenceHelper;
@ -69,17 +70,17 @@ public class SynchronizedStatement extends Statement {
  // public methods
  // *****************************************************************************

-  public String toJava(int indent, BytecodeMappingTracer tracer) {
+  public TextBuffer toJava(int indent, BytecodeMappingTracer tracer) {
    String indstr = InterpreterUtil.getIndentString(indent);

    String new_line_separator = DecompilerContext.getNewLineSeparator();

-    StringBuilder buf = new StringBuilder();
+    TextBuffer buf = new TextBuffer();
    buf.append(ExprProcessor.listToJava(varDefinitions, indent, tracer));
    buf.append(first.toJava(indent, tracer));

    if (isLabeled()) {
-      buf.append(indstr).append("label").append(this.id).append(":").append(new_line_separator);
+      buf.append(indstr).append("label").append(this.id.toString()).append(":").append(new_line_separator);
      tracer.incrementCurrentSourceLine();
    }

@ -92,7 +93,7 @@ public class SynchronizedStatement extends Statement {
    buf.append(indstr).append("}").append(new_line_separator);
    tracer.incrementCurrentSourceLine();

-    return buf.toString();
+    return buf;
  }

  public void initExprents() {