diff --git a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index bfb9a80b673..3520c0a4b0f 100644
--- a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -63,6 +63,8 @@ public class ExpressionCodegen extends JetVisitor {
     private final Stack<Label> myBreakTargets = new Stack<Label>();
     private final Stack<StackValue> myStack = new Stack<StackValue>();
 
+    private int myLastLineNumber = -1;
+
     private static final String[] PRIMITIVE_TYPE_INFO_FIELDS = {
             null,
             "BOOL_TYPE_INFO",
@@ -116,7 +118,7 @@ public class ExpressionCodegen extends JetVisitor {
     }
 
     private void gen(JetElement expr) {
-        if (expr == null) throw new CompilationException();
+        markLineNumber(expr);
         expr.accept(this);
     }
 
@@ -582,7 +584,6 @@ public class ExpressionCodegen extends JetVisitor {
 
         for (int i = 0, statementsSize = statements.size(); i < statementsSize; i++) {
             JetElement statement = statements.get(i);
-            markLineNumber(statement);
             if (i == statements.size() - 1) {
                 gen(statement);
             }
@@ -609,10 +610,15 @@ public class ExpressionCodegen extends JetVisitor {
     private void markLineNumber(JetElement statement) {
         final Document document = statement.getContainingFile().getViewProvider().getDocument();
         if (document != null) {
-            int lineNumber = document.getLineNumber(statement.getTextRange().getStartOffset());
+            int lineNumber = document.getLineNumber(statement.getTextRange().getStartOffset());  // 0-based
+            if (lineNumber == myLastLineNumber) {
+                return;
+            }
+            myLastLineNumber = lineNumber;
+
             Label label = new Label();
             v.visitLabel(label);
-            v.visitLineNumber(lineNumber, label);
+            v.visitLineNumber(lineNumber+1, label);  // 1-based
         }
     }
 
diff --git a/idea/src/org/jetbrains/jet/plugin/debugger/JetPositionManager.java b/idea/src/org/jetbrains/jet/plugin/debugger/JetPositionManager.java
index 3057038b8f6..2c8d5ac5277 100644
--- a/idea/src/org/jetbrains/jet/plugin/debugger/JetPositionManager.java
+++ b/idea/src/org/jetbrains/jet/plugin/debugger/JetPositionManager.java
@@ -5,8 +5,11 @@ import com.intellij.debugger.PositionManager;
 import com.intellij.debugger.SourcePosition;
 import com.intellij.debugger.engine.DebugProcess;
 import com.intellij.debugger.requests.ClassPrepareRequestor;
+import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.PsiFile;
+import com.intellij.psi.search.FilenameIndex;
+import com.intellij.psi.search.ProjectScope;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.sun.jdi.AbsentInformationException;
 import com.sun.jdi.Location;
@@ -37,11 +40,41 @@ public class JetPositionManager implements PositionManager {
     @Override
     @Nullable
     public SourcePosition getSourcePosition(@Nullable Location location) throws NoDataException {
+        if (location == null) {
+            throw new NoDataException();
+        }
         PsiFile psiFile = getPsiFileByLocation(location);
+
+        int lineNumber;
+        try {
+            lineNumber = location.lineNumber() - 1;
+        } catch (InternalError e) {
+            lineNumber = -1;
+        }
+
+        if (lineNumber >= 0) {
+            return SourcePosition.createFromLine(psiFile, lineNumber);
+        }
+
         throw new NoDataException();
     }
 
-    private PsiFile getPsiFileByLocation(Location location) {
+    private PsiFile getPsiFileByLocation(Location location) throws NoDataException {
+        try {
+            final String sourceName = location.sourceName();
+            final Project project = myDebugProcess.getProject();
+            final PsiFile[] files = FilenameIndex.getFilesByName(project, sourceName, ProjectScope.getAllScope(project));
+            if (files.length == 1 && files[0] instanceof JetFile) {
+                return files[0];
+            }
+
+        } catch (AbsentInformationException e) {
+            throw new NoDataException();
+        }
+
+
+        /* TODO
+
         final ReferenceType referenceType = location.declaringType();
         if (referenceType == null) {
             return null;
@@ -49,6 +82,8 @@ public class JetPositionManager implements PositionManager {
 
         // TODO
         return null;
+        */
+        throw new NoDataException();
     }
 
     @NotNull