decompiler: build original lines mapping

src/org/jetbrains/java/decompiler/main/ClassWriter.java

@@ -577,10 +577,9 @@ public class ClassWriter {
       boolean isDeprecated = mt.getAttributes().containsKey("Deprecated");
       boolean clinit = false, init = false, dinit = false;
 
-      StructLineNumberTableAttribute lineNumberTable = null;
-      if (DecompilerContext.getOption(IFernflowerPreferences.USE_DEBUG_LINE_NUMBERS)) {
-        lineNumberTable = (StructLineNumberTableAttribute)mt.getAttributes().getWithKey(StructGeneralAttribute.ATTRIBUTE_LINE_NUMBER_TABLE);
-      }
+      StructLineNumberTableAttribute lineNumberTable =
+        (StructLineNumberTableAttribute)mt.getAttributes().getWithKey(StructGeneralAttribute.ATTRIBUTE_LINE_NUMBER_TABLE);
+      tracer.setLineNumberTable(lineNumberTable);
 
       MethodDescriptor md = MethodDescriptor.parseDescriptor(mt.getDescriptor());
 
@@ -797,7 +796,7 @@ public class ClassWriter {
         }
 
         // We do not have line information for method start, lets have it here for now
-        if (lineNumberTable != null) {
+        if (lineNumberTable != null && DecompilerContext.getOption(IFernflowerPreferences.USE_DEBUG_LINE_NUMBERS)) {
           buffer.setCurrentLine(lineNumberTable.getFirstLine() - 1);
         }
         buffer.append('{').appendLineSeparator();
@@ -813,7 +812,7 @@ public class ClassWriter {
 
             hideMethod = (clinit || dinit || hideConstructor(wrapper, init, throwsExceptions, paramCount)) && code.length() == 0;
 
-            if (!hideMethod && lineNumberTable != null) {
+            if (!hideMethod && lineNumberTable != null && DecompilerContext.getOption(IFernflowerPreferences.USE_DEBUG_LINE_NUMBERS)) {
               mapLines(code, lineNumberTable, tracer, startLine);
             }
 

src/org/jetbrains/java/decompiler/main/TextBuffer.java

@@ -63,6 +63,11 @@ public class TextBuffer {
     return this;
   }
 
+  public TextBuffer append(int i) {
+    myStringBuilder.append(i);
+    return this;
+  }
+
   public TextBuffer appendLineSeparator() {
     myStringBuilder.append(myLineSeparator);
     return this;

src/org/jetbrains/java/decompiler/main/collectors/BytecodeMappingTracer.java

@@ -1,6 +1,10 @@
 package org.jetbrains.java.decompiler.main.collectors;
 
+import org.jetbrains.java.decompiler.struct.attr.StructLineNumberTableAttribute;
+
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
@@ -8,6 +12,8 @@ public class BytecodeMappingTracer {
 
   private int current_sourceline;
 
+  private StructLineNumberTableAttribute myLineNumberTable = null;
+
   // bytecode offset, source line
   private HashMap<Integer, Integer> mapping = new HashMap<Integer, Integer>();
 
@@ -67,4 +73,30 @@ public class BytecodeMappingTracer {
     this.current_sourceline = current_sourceline;
   }
 
+  public void setLineNumberTable(StructLineNumberTableAttribute lineNumberTable) {
+    myLineNumberTable = lineNumberTable;
+  }
+
+  public Map<Integer, Integer> getOriginalLinesMapping() {
+    if (myLineNumberTable == null) {
+      return Collections.emptyMap();
+    }
+    HashMap<Integer, Integer> res = new HashMap<Integer, Integer>();
+    int[] data = myLineNumberTable.getRawData();
+    for (int i = 0; i < data.length; i+=2) {
+      int originalOffset = data[i];
+      int originalLine = data[i+1];
+      Integer newLine = mapping.get(originalOffset);
+      if (newLine != null) {
+        res.put(originalLine, newLine);
+      }
+    }
+    for (Entry<Integer, Integer> entry : mapping.entrySet()) {
+      int originalLine = myLineNumberTable.findLineNumber(entry.getKey());
+      if (originalLine > -1) {
+        res.put(originalLine, entry.getValue());
+      }
+    }
+    return res;
+  }
 }

src/org/jetbrains/java/decompiler/main/collectors/BytecodeSourceMapper.java

@@ -10,6 +10,8 @@ public class BytecodeSourceMapper {
 
   private int offset_total;
 
+  private final HashMap<Integer, Integer> myOriginalLinesMapping = new HashMap<Integer, Integer>();
+
   // class, method, bytecode offset, source line
   private final HashMap<String, HashMap<String, HashMap<Integer, Integer>>> mapping = new LinkedHashMap<String, HashMap<String, HashMap<Integer, Integer>>>(); // need to preserve order
 
@@ -35,6 +37,7 @@ public class BytecodeSourceMapper {
     for(Entry<Integer, Integer> entry : tracer.getMapping().entrySet()) {
       addMapping(classname, methodname, entry.getKey(), entry.getValue());
     }
+    myOriginalLinesMapping.putAll(tracer.getOriginalLinesMapping());
   }
 
   public void dumpMapping(TextBuffer buffer, boolean offsetsToHex) {
@@ -69,6 +72,13 @@ public class BytecodeSourceMapper {
       }
       buffer.append("}").appendLineSeparator();
     }
+
+    // lines mapping
+    buffer.append("Lines mapping:").appendLineSeparator();
+    int[] mapping = getOriginalLinesMapping();
+    for (int i = 0; i < mapping.length; i+=2) {
+      buffer.append(mapping[i]).append(" <-> ").append(mapping[i+1]).appendLineSeparator();
+    }
   }
 
   public int getTotalOffset() {
@@ -83,5 +93,17 @@ public class BytecodeSourceMapper {
     this.offset_total += offset_total;
   }
 
-
+  /**
+   * original to our line mapping
+   */
+  public int[] getOriginalLinesMapping() {
+    int[] res = new int[myOriginalLinesMapping.size()*2];
+    int i = 0;
+    for (Entry<Integer, Integer> entry : myOriginalLinesMapping.entrySet()) {
+      res[i] = entry.getKey();
+      res[i+1] = entry.getValue() + offset_total + 1; // make it 1 based
+      i+=2;
+    }
+    return res;
+  }
 }

src/org/jetbrains/java/decompiler/struct/attr/StructLineNumberTableAttribute.java

@@ -63,4 +63,8 @@ public class StructLineNumberTableAttribute extends StructGeneralAttribute {
     }
     return -1;
   }
+
+  public int[] getRawData() {
+    return myLineInfo;
+  }
 }

testData/results/TestClassSimpleBytecodeMapping.dec

@@ -55,3 +55,13 @@ class pkg/TestClassSimpleBytecodeMapping{
       1      20
    }
 }
+Lines mapping:
+17 <-> 8
+21 <-> 11
+22 <-> 12
+23 <-> 13
+25 <-> 15
+26 <-> 16
+12 <-> 5
+14 <-> 6
+31 <-> 21