Introduces another approach for setting temporary breakpoints at

methods' start lines when stepping in, due to bug in google chrome:
http://code.google.com/p/chromium/issues/detail?id=407105

teavm-core/src/main/java/org/teavm/common/RecordArray.java

@@ -27,21 +27,26 @@ public class RecordArray {
     private int[] data;
     private int[] substart;
     private int[] subdata;
+    private int size;
 
-    RecordArray(int recordSize, int arraysPerRecord, int[] data, int[] substart, int[] subdata) {
+    RecordArray(int recordSize, int arraysPerRecord, int size, int[] data, int[] substart, int[] subdata) {
         this.recordSize = recordSize;
         this.arraysPerRecord = arraysPerRecord;
+        this.size = size;
         this.data = data;
         this.substart = substart;
         this.subdata = subdata;
     }
 
     public Record get(int index) {
+        if (index < 0 || index >= size) {
+            throw new IndexOutOfBoundsException("Index " + index + " is outside of [0; " + size + ")");
+        }
         return new Record(index * recordSize, index * arraysPerRecord);
     }
 
     public int size() {
-        return data.length / recordSize;
+        return size;
     }
 
     public int getRecordSize() {

teavm-core/src/main/java/org/teavm/common/RecordArrayBuilder.java

@@ -22,6 +22,7 @@ package org.teavm.common;
 public class RecordArrayBuilder {
     private int recordSize;
     private int arraysPerRecord;
+    private int size;
     private IntegerArray data = new IntegerArray(1);
     private IntegerArray substart = new IntegerArray(1);
     private IntegerArray subdata = new IntegerArray(1);
@@ -33,6 +34,9 @@ public class RecordArrayBuilder {
     }
 
     public Record get(int index) {
+        if (index < 0 || index >= size) {
+            throw new IndexOutOfBoundsException("Index " + index + " is outside of [0; " + size + ")");
+        }
         return new Record(index * recordSize, index * arraysPerRecord);
     }
 
@@ -45,11 +49,12 @@ public class RecordArrayBuilder {
         for (int i = 0; i < arraysPerRecord; ++i) {
             substart.add(-1);
         }
+        ++size;
         return new Record(offset, arrayOffset);
     }
 
     public int size() {
-        return data.size() / recordSize;
+        return size;
     }
 
     public int getRecordSize() {
@@ -71,7 +76,7 @@ public class RecordArrayBuilder {
             }
             builtSubstart[i + 1] = builtSubdata.size();
         }
-        return new RecordArray(recordSize, arraysPerRecord, data.getAll(), builtSubstart, builtSubdata.getAll());
+        return new RecordArray(recordSize, arraysPerRecord, size, data.getAll(), builtSubstart, builtSubdata.getAll());
     }
 
     public class Record {

teavm-core/src/main/java/org/teavm/debugging/DebugInformation.java

@@ -18,6 +18,8 @@ package org.teavm.debugging;
 import java.io.*;
 import java.util.*;
 import org.teavm.common.IntegerArray;
+import org.teavm.common.RecordArray;
+import org.teavm.common.RecordArrayBuilder;
 import org.teavm.model.MethodDescriptor;
 import org.teavm.model.MethodReference;
 
@@ -45,6 +47,7 @@ public class DebugInformation {
     Mapping lineMapping;
     Mapping callSiteMapping;
     MultiMapping[] variableMappings;
+    RecordArray[] lineCallSites;
     CFG[] controlFlowGraphs;
     List<ClassMetadata> classesMetadata;
     MethodEntrances methodEntrances;
@@ -258,6 +261,24 @@ public class DebugInformation {
         }
     }
 
+    public MethodReference[] getCallSites(SourceLocation location) {
+        Integer fileIndex = fileNameMap.get(location.getFileName());
+        if (fileIndex == null) {
+            return new MethodReference[0];
+        }
+        RecordArray mapping = lineCallSites[fileIndex];
+        if (location.getLine() >= mapping.size()) {
+            return new MethodReference[0];
+        }
+        int[] callSiteIds = mapping.get(location.getLine()).getArray(0);
+        MethodReference[] methods = new MethodReference[callSiteIds.length];
+        for (int i = 0; i < callSiteIds.length; ++i) {
+            int exactMethodId = callSiteMapping.values[callSiteIds[i]];
+            methods[i] = getExactMethod(exactMethodId);
+        }
+        return methods;
+    }
+
     private <T> T componentByKey(Mapping mapping, T[] values, GeneratedLocation location) {
         int keyIndex = indexByKey(mapping, location);
         int valueIndex = keyIndex >= 0 ? mapping.values[keyIndex] : -1;
@@ -283,6 +304,11 @@ public class DebugInformation {
         return index >= 0 ? index : -index - 2;
     }
 
+    private int valueByKey(Mapping mapping, GeneratedLocation location) {
+        int index = indexByKey(mapping, location);
+        return index >= 0 ? mapping.values[index] : -1;
+    }
+
     private int indexByKey(MultiMapping mapping, GeneratedLocation location) {
         int index = Collections.binarySearch(mapping.keyList(), location);
         return index >= 0 ? index : -index - 2;
@@ -307,6 +333,7 @@ public class DebugInformation {
         rebuildFileDescriptions();
         rebuildEntrances();
         rebuildMethodTree();
+        rebuildLineCallSites();
     }
 
     void rebuildMaps() {
@@ -439,6 +466,32 @@ public class DebugInformation {
         return exactMethodMap.get(entry);
     }
 
+    private void rebuildLineCallSites() {
+        lineCallSites = new RecordArray[fileNames.length];
+        RecordArrayBuilder[] builders = new RecordArrayBuilder[fileNames.length];
+        for (int i = 0; i < lineCallSites.length; ++i) {
+            builders[i] = new RecordArrayBuilder(0, 1);
+        }
+        for (int i = 0; i < callSiteMapping.lines.length; ++i) {
+            GeneratedLocation loc = callSiteMapping.key(i);
+            int methodId = callSiteMapping.values[i];
+            if (methodId >= 0) {
+                int line = valueByKey(lineMapping, loc);
+                int fileId = valueByKey(fileMapping, loc);
+                if (fileId >= 0 && line >= 0) {
+                    RecordArrayBuilder builder = builders[fileId];
+                    while (builder.size() <= line) {
+                        builder.add();
+                    }
+                    builder.get(line).getArray(0).add(i);
+                }
+            }
+        }
+        for (int i = 0; i < lineCallSites.length; ++i) {
+            lineCallSites[i] = builders[i].build();
+        }
+    }
+
     class MethodEntrancesBuilder {
         int[] start;
         IntegerArray data;

teavm-core/src/main/java/org/teavm/debugging/Debugger.java

@@ -98,18 +98,18 @@ public class Debugger {
         for (CallFrame frame : callStack) {
             boolean exits;
             String script = frame.originalLocation.getScript();
-            GeneratedLocation genLoc = new GeneratedLocation(frame.originalLocation.getLine(),
-                    frame.originalLocation.getColumn());
             DebugInformation debugInfo = debugInformationMap.get(script);
-            if (frame.getLocation() != null && debugInfo != null) {
-                exits = false;
-                MethodReference callMethod = debugInfo.getCallSite(genLoc);
+            if (frame.getLocation() != null && frame.getLocation().getFileName() != null &&
+                    frame.getLocation().getLine() >= 0 && debugInfo != null) {
+                MethodReference[] callMethods = debugInfo.getCallSites(frame.getLocation());
                 exits = addFollowing(debugInfo, frame.getLocation(), script, new HashSet<SourceLocation>(),
                         successors);
-                if (enterMethod && callMethod != null) {
-                    for (MethodReference potentialMethod : debugInfo.getOverridingMethods(callMethod)) {
-                        for (GeneratedLocation loc : debugInfo.getMethodEntrances(potentialMethod)) {
-                            successors.add(new JavaScriptLocation(script, loc.getLine(), loc.getColumn()));
+                if (enterMethod) {
+                    for (MethodReference callMethod : callMethods) {
+                        for (MethodReference potentialMethod : debugInfo.getOverridingMethods(callMethod)) {
+                            for (GeneratedLocation loc : debugInfo.getMethodEntrances(potentialMethod)) {
+                                successors.add(new JavaScriptLocation(script, loc.getLine(), loc.getColumn()));
+                            }
                         }
                     }
                 }