Fixes variable mapping

teavm-classlib/src/main/java/org/teavm/classlib/impl/JavacSupport.java

@@ -33,8 +33,8 @@ public class JavacSupport implements ClassHolderTransformer {
                     ValueType.object("javax.tools.JavaCompiler")));
             Program program = new Program();
             BasicBlock block = program.createBasicBlock();
-            program.createVariable(null);
+            program.createVariable();
-            Variable var = program.createVariable(null);
+            Variable var = program.createVariable();
             ConstructInstruction construct = new ConstructInstruction();
             construct.setReceiver(var);
             construct.setType("com.sun.tools.javac.api.JavacTool");

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

@@ -54,10 +54,13 @@ public class IntegerArray {
         return data[index];
     }
 
+    public int[] getRange(int start, int end) {
+        return Arrays.copyOfRange(data, start, end);
+    }
+
     public void set(int index, int value) {
         if (index >= sz) {
-            throw new IndexOutOfBoundsException("Index " + index +
+            throw new IndexOutOfBoundsException("Index " + index + " is greater than the list size " + sz);
-                    " is greater than the list size " + sz);
         }
         data[index] = value;
     }
@@ -90,6 +93,15 @@ public class IntegerArray {
         data[sz - 1] = item;
     }
 
+    public void remove(int index) {
+        remove(index, 1);
+    }
+
+    public void remove(int index, int count) {
+        System.arraycopy(data, index + count, data, index, sz - index - count);
+        sz -= count;
+    }
+
     public boolean contains(int item) {
         for (int i = 0; i < sz; ++i) {
             if (data[i] == item) {

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

@@ -44,7 +44,7 @@ public class DebugInformation {
     Mapping classMapping;
     Mapping methodMapping;
     Mapping lineMapping;
-    Mapping[] variableMappings;
+    MultiMapping[] variableMappings;
     List<Map<Integer, Integer>> classesMetadata;
 
     public String[] getCoveredSourceFiles() {
@@ -105,18 +105,18 @@ public class DebugInformation {
         return getMethodAt(new GeneratedLocation(line, column));
     }
 
-    public String getVariableMeaningAt(int line, int column, String variable) {
+    public String[] getVariableMeaningAt(int line, int column, String variable) {
         return getVariableMeaningAt(new GeneratedLocation(line, column), variable);
     }
 
-    public String getVariableMeaningAt(GeneratedLocation location, String variable) {
+    public String[] getVariableMeaningAt(GeneratedLocation location, String variable) {
         Integer varIndex = variableNameMap.get(variable);
         if (varIndex == null) {
-            return null;
+            return new String[0];
         }
-        Mapping mapping = variableMappings[varIndex];
+        MultiMapping mapping = variableMappings[varIndex];
         if (mapping == null) {
-            return null;
+            return new String[0];
         }
         return componentByKey(mapping, variableNames, location);
     }
@@ -140,11 +140,30 @@ public class DebugInformation {
         return valueIndex >= 0 ? values[valueIndex] : null;
     }
 
+    private String[] componentByKey(MultiMapping mapping, String[] values, GeneratedLocation location) {
+        int keyIndex = indexByKey(mapping, location);
+        if (keyIndex < 0) {
+            return new String[0];
+        }
+        int start = mapping.offsets[keyIndex];
+        int end = mapping.offsets[keyIndex + 1];
+        String[] result = new String[end - start];
+        for (int i = 0; i < result.length; ++i) {
+            result[i] = values[mapping.data[i + start]];
+        }
+        return result;
+    }
+
     private int indexByKey(Mapping mapping, GeneratedLocation location) {
         int index = Collections.binarySearch(mapping.keyList(), location);
         return index >= 0 ? index : -index - 2;
     }
 
+    private int indexByKey(MultiMapping mapping, GeneratedLocation location) {
+        int index = Collections.binarySearch(mapping.keyList(), location);
+        return index >= 0 ? index : -index - 2;
+    }
+
     public void write(OutputStream output) throws IOException {
         DebugInformationWriter writer = new DebugInformationWriter(new DataOutputStream(output));
         writer.write(this);
@@ -308,6 +327,32 @@ public class DebugInformation {
         }
     }
 
+    static class MultiMapping {
+        int[] lines;
+        int[] columns;
+        int[] offsets;
+        int[] data;
+
+        public MultiMapping(int[] lines, int[] columns, int[] offsets, int[] data) {
+            this.lines = lines;
+            this.columns = columns;
+            this.offsets = offsets;
+            this.data = data;
+        }
+
+        public LocationList keyList() {
+            return new LocationList(lines, columns);
+        }
+
+        public int size() {
+            return lines.length;
+        }
+
+        public GeneratedLocation key(int index) {
+            return new GeneratedLocation(lines[index], columns[index]);
+        }
+    }
+
     static class LocationList extends AbstractList<GeneratedLocation> {
         private int[] lines;
         private int[] columns;

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

@@ -36,7 +36,7 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
     private Mapping lineMapping = new Mapping();
     private Mapping classMapping = new Mapping();
     private Mapping methodMapping = new Mapping();
-    private Map<Integer, Mapping> variableMappings = new HashMap<>();
+    private Map<Integer, MultiMapping> variableMappings = new HashMap<>();
     private MethodDescriptor currentMethod;
     private String currentClass;
     private String currentFileName;
@@ -88,15 +88,19 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
     }
 
     @Override
-    public void emitVariable(String sourceName, String generatedName) {
+    public void emitVariable(String[] sourceNames, String generatedName) {
-        int sourceIndex = variableNames.index(sourceName);
+        int[] sourceIndexes = new int[sourceNames.length];
+        for (int i = 0; i < sourceIndexes.length; ++i) {
+            sourceIndexes[i] = variableNames.index(sourceNames[i]);
+        }
+        Arrays.sort(sourceIndexes);
         int generatedIndex = variableNames.index(generatedName);
-        Mapping mapping = variableMappings.get(generatedIndex);
+        MultiMapping mapping = variableMappings.get(generatedIndex);
         if (mapping == null) {
-            mapping = new Mapping();
+            mapping = new MultiMapping();
             variableMappings.put(generatedIndex, mapping);
         }
-        mapping.add(locationProvider, sourceIndex);
+        mapping.add(locationProvider, sourceIndexes);
     }
 
     @Override
@@ -130,9 +134,9 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
             debugInformation.lineMapping = lineMapping.build();
             debugInformation.classMapping = classMapping.build();
             debugInformation.methodMapping = methodMapping.build();
-            debugInformation.variableMappings = new DebugInformation.Mapping[variableNames.list.size()];
+            debugInformation.variableMappings = new DebugInformation.MultiMapping[variableNames.list.size()];
             for (int var : variableMappings.keySet()) {
-                Mapping mapping = variableMappings.get(var);
+                MultiMapping mapping = variableMappings.get(var);
                 debugInformation.variableMappings[var] = mapping.build();
             }
 
@@ -163,6 +167,12 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
                 int last = lines.size() - 1;
                 if (lines.get(last) == location.getLine() && columns.get(last) == location.getColumn()) {
                     values.set(last, value);
+                    // TODO: check why this gives an invalid result
+                    /*if (values.get(last) == values.get(last - 1)) {
+                        values.remove(last);
+                        lines.remove(last);
+                        columns.remove(last);
+                    }*/
                     return;
                 }
             }
@@ -176,6 +186,78 @@ public class DebugInformationBuilder implements DebugInformationEmitter {
         }
     }
 
+    static class MultiMapping {
+        IntegerArray lines = new IntegerArray(1);
+        IntegerArray columns = new IntegerArray(1);
+        IntegerArray offsets = new IntegerArray(1);
+        IntegerArray data = new IntegerArray(1);
+
+        public MultiMapping() {
+            offsets.add(0);
+        }
+
+        public void add(LocationProvider location, int[] values) {
+            if (lines.size() > 1) {
+                int last = lines.size() - 1;
+                if (lines.get(last) == location.getLine() && columns.get(last) == location.getColumn()) {
+                    addToLast(values);
+                    return;
+                }
+            }
+            lines.add(location.getLine());
+            columns.add(location.getColumn());
+            data.addAll(values);
+            offsets.add(data.size());
+        }
+
+        private void addToLast(int[] values) {
+            int start = offsets.get(offsets.size() - 2);
+            int end = offsets.get(offsets.size() - 1);
+            int[] existing = data.getRange(start, end);
+            values = merge(existing, values);
+            if (values.length == existing.length) {
+                return;
+            }
+            data.remove(start, end - start);
+            data.addAll(values);
+            offsets.set(offsets.size() - 1, data.size());
+        }
+
+        private int[] merge(int[] a, int[] b) {
+            int[] result = new int[a.length + b.length];
+            int i = 0;
+            int j = 0;
+            int k = 0;
+            while (i < a.length && j < b.length) {
+                int p = a[i];
+                int q = b[j];
+                if (p == q) {
+                    result[k++] = p;
+                    ++i;
+                    ++j;
+                } else if (p < q) {
+                    result[k++] = p;
+                    ++i;
+                } else {
+                    result[k++] = q;
+                    ++j;
+                }
+            }
+            while (i < a.length) {
+                result[k++] = a[i++];
+            }
+            while (j < b.length) {
+                result[k++] = b[j++];
+            }
+            return k < result.length ? Arrays.copyOf(result, k) : result;
+        }
+
+        public DebugInformation.MultiMapping build() {
+            return new DebugInformation.MultiMapping(lines.getAll(), columns.getAll(), offsets.getAll(),
+                    data.getAll());
+        }
+    }
+
     static class MappedList {
         private List<String> list = new ArrayList<>();
         private Map<String, Integer> map = new HashMap<>();

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

@@ -31,7 +31,7 @@ public interface DebugInformationEmitter {
 
     void emitClass(String className);
 
-    void emitVariable(String sourceName, String generatedName);
+    void emitVariable(String[] sourceNames, String generatedName);
 
     void addClass(String className);
 

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

@@ -53,13 +53,13 @@ class DebugInformationReader {
         return debugInfo;
     }
 
-    private DebugInformation.Mapping[] readVariableMappings(int count) throws IOException {
+    private DebugInformation.MultiMapping[] readVariableMappings(int count) throws IOException {
-        DebugInformation.Mapping[] mappings = new DebugInformation.Mapping[count];
+        DebugInformation.MultiMapping[] mappings = new DebugInformation.MultiMapping[count];
         int varCount = readUnsignedNumber();
         int lastVar = 0;
         while (varCount-- > 0) {
             lastVar += readUnsignedNumber();
-            mappings[lastVar] = readMapping();
+            mappings[lastVar] = readMultiMapping();
         }
         return mappings;
     }
@@ -86,6 +86,32 @@ class DebugInformationReader {
         return !negative ? number : -number;
     }
 
+    private DebugInformation.MultiMapping readMultiMapping() throws IOException {
+        int[] lines = readRle();
+        int last = 0;
+        for (int i = 0; i < lines.length; ++i) {
+            last += lines[i];
+            lines[i] = last;
+        }
+        int[] columns = new int[lines.length];
+        resetRelativeNumber();
+        for (int i = 0; i < columns.length; ++i) {
+            columns[i] = readRelativeNumber();
+        }
+        int[] offsets = new int[lines.length + 1];
+        int lastOffset = 0;
+        for (int i = 1; i < offsets.length; ++i) {
+            lastOffset += readUnsignedNumber();
+            offsets[i] = lastOffset;
+        }
+        int[] data = new int[lastOffset];
+        resetRelativeNumber();
+        for (int i = 0; i < data.length; ++i) {
+            data[i] = readRelativeNumber();
+        }
+        return new DebugInformation.MultiMapping(lines, columns, offsets, data);
+    }
+
     private DebugInformation.Mapping readMapping() throws IOException {
         int[] lines = readRle();
         int last = 0;

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

@@ -53,7 +53,7 @@ class DebugInformationWriter {
         int lastVar = 0;
         writeUnsignedNumber(nonNullVariableMappings(debugInfo));
         for (int i = 0; i < debugInfo.variableMappings.length; ++i) {
-            DebugInformation.Mapping mapping = debugInfo.variableMappings[i];
+            DebugInformation.MultiMapping mapping = debugInfo.variableMappings[i];
             if (mapping == null) {
                 continue;
             }
@@ -94,6 +94,30 @@ class DebugInformationWriter {
         }
     }
 
+    private void writeMapping(DebugInformation.MultiMapping mapping) throws IOException {
+        int[] lines = mapping.lines.clone();
+        int last = 0;
+        for (int i = 0; i < lines.length; ++i) {
+            int next = lines[i];
+            lines[i] -= last;
+            last = next;
+        }
+        writeRle(lines);
+        resetRelativeNumber();
+        for (int i = 0; i < mapping.columns.length; ++i) {
+            writeRelativeNumber(mapping.columns[i]);
+        }
+        int lastOffset = 0;
+        for (int i = 1; i < mapping.offsets.length; ++i) {
+            writeUnsignedNumber(mapping.offsets[i] - lastOffset);
+            lastOffset = mapping.offsets[i];
+        }
+        resetRelativeNumber();
+        for (int i = 0; i < mapping.data.length; ++i) {
+            writeRelativeNumber(mapping.data[i]);
+        }
+    }
+
     private void writeMapping(DebugInformation.Mapping mapping) throws IOException {
         int[] lines = mapping.lines.clone();
         int last = 0;

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

@@ -280,15 +280,15 @@ public class Debugger {
         }
     }
 
-    public String mapVariable(String variable, JavaScriptLocation location) {
+    String[] mapVariable(String variable, JavaScriptLocation location) {
         DebugInformation debugInfo = debugInformationMap.get(location.getScript());
         if (debugInfo == null) {
-            return null;
+            return new String[0];
         }
         return debugInfo.getVariableMeaningAt(location.getLine(), location.getColumn(), variable);
     }
 
-    public String mapField(String className, String jsField) {
+    String mapField(String className, String jsField) {
         for (DebugInformation debugInfo : debugInformationMap.values()) {
             String meaning = debugInfo.getFieldMeaning(className, jsField);
             if (meaning != null) {

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

@@ -37,7 +37,7 @@ public class DummyDebugInformationEmitter implements DebugInformationEmitter {
     }
 
     @Override
-    public void emitVariable(String sourceName, String generatedName) {
+    public void emitVariable(String[] sourceName, String generatedName) {
     }
 
     @Override

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

@@ -62,12 +62,11 @@ class VariableMap extends AbstractMap<String, Variable> {
         Map<String, Variable> vars = new HashMap<>();
         for (Map.Entry<String, JavaScriptVariable> entry : jsVariables.entrySet()) {
             JavaScriptVariable jsVar = entry.getValue();
-            String name = debugger.mapVariable(entry.getKey(), location);
+            String[] names = debugger.mapVariable(entry.getKey(), location);
-            if (name == null) {
-                continue;
-            }
             Value value = new Value(debugger, jsVar.getValue());
-            vars.put(entry.getKey(), new Variable(name, value));
+            for (String name : names) {
+                vars.put(name, new Variable(name, value));
+            }
         }
         backingMap.compareAndSet(null, vars);
     }

teavm-core/src/main/java/org/teavm/javascript/Decompiler.java

@@ -271,7 +271,7 @@ public class Decompiler {
         int paramCount = method.getSignature().length;
         for (int i = 0; i < paramCount; ++i) {
             Variable var = program.variableAt(i);
-            methodNode.getParameterDebugNames().add(var.getDebugName());
+            methodNode.getParameterDebugNames().add(new HashSet<>(var.getDebugNames()));
         }
         return methodNode;
     }

teavm-core/src/main/java/org/teavm/javascript/NullPointerExceptionTransformer.java

@@ -49,7 +49,7 @@ public class NullPointerExceptionTransformer implements ClassHolderTransformer {
                 }
                 NullCheckInstruction nullCheck = new NullCheckInstruction();
                 nullCheck.setValue(invoke.getInstance());
-                Variable var = block.getProgram().createVariable(null);
+                Variable var = block.getProgram().createVariable();
                 nullCheck.setReceiver(var);
                 invoke.setInstance(var);
                 block.getInstructions().add(i++, nullCheck);

teavm-core/src/main/java/org/teavm/javascript/Renderer.java

@@ -522,7 +522,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             try {
                 MethodReference ref = method.getReference();
                 for (int i = 0; i < method.getParameterDebugNames().size(); ++i) {
-                    debugEmitter.emitVariable(method.getParameterDebugNames().get(i), variableName(i));
+                    debugEmitter.emitVariable(method.getParameterDebugNames().get(i).toArray(new String[0]),
+                            variableName(i));
                 }
                 int variableCount = 0;
                 for (int var : method.getVariables()) {
@@ -609,7 +610,8 @@ public class Renderer implements ExprVisitor, StatementVisitor, RenderingContext
             }
             if (statement.getLeftValue() instanceof VariableExpr) {
                 VariableExpr receiver = (VariableExpr)statement.getLeftValue();
-                debugEmitter.emitVariable(statement.getDebugName(), variableName(receiver.getIndex()));
+                debugEmitter.emitVariable(statement.getDebugNames().toArray(new String[0]),
+                        variableName(receiver.getIndex()));
             }
         } catch (IOException e) {
             throw new RenderingException("IO error occured", e);

teavm-core/src/main/java/org/teavm/javascript/StatementGenerator.java

@@ -244,7 +244,7 @@ class StatementGenerator implements InstructionVisitor {
     public void visit(AssignInstruction insn) {
         AssignmentStatement stmt = Statement.assign(Expr.var(insn.getReceiver().getIndex()),
                 Expr.var(insn.getAssignee().getIndex()));
-        stmt.setDebugName(insn.getReceiver().getDebugName());
+        stmt.getDebugNames().addAll(insn.getReceiver().getDebugNames());
         stmt.setLocation(currentLocation);
         statements.add(stmt);
     }
@@ -574,7 +574,7 @@ class StatementGenerator implements InstructionVisitor {
     private void assign(Expr source, Variable target) {
         AssignmentStatement stmt = Statement.assign(Expr.var(target.getIndex()), source);
         stmt.setLocation(currentLocation);
-        stmt.setDebugName(target.getDebugName());
+        stmt.getDebugNames().addAll(target.getDebugNames());
         statements.add(stmt);
     }
 

teavm-core/src/main/java/org/teavm/javascript/ast/AssignmentStatement.java

@@ -15,6 +15,9 @@
  */
 package org.teavm.javascript.ast;
 
+import java.util.HashSet;
+import java.util.Set;
+
 /**
  *
  * @author Alexey Andreev
@@ -23,7 +26,7 @@ public class AssignmentStatement extends Statement {
     private Expr leftValue;
     private Expr rightValue;
     private NodeLocation location;
-    private String debugName;
+    private Set<String> debugNames = new HashSet<>();
 
     public Expr getLeftValue() {
         return leftValue;
@@ -49,12 +52,8 @@ public class AssignmentStatement extends Statement {
         this.location = location;
     }
 
-    public String getDebugName() {
+    public Set<String> getDebugNames() {
-        return debugName;
+        return debugNames;
-    }
-
-    public void setDebugName(String debugName) {
-        this.debugName = debugName;
     }
 
     @Override

teavm-core/src/main/java/org/teavm/javascript/ast/RegularMethodNode.java

@@ -17,6 +17,7 @@ package org.teavm.javascript.ast;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 import org.teavm.model.MethodReference;
 
 /**
@@ -26,7 +27,7 @@ import org.teavm.model.MethodReference;
 public class RegularMethodNode extends MethodNode {
     private Statement body;
     private List<Integer> variables = new ArrayList<>();
-    private List<String> parameterDebugNames = new ArrayList<>();
+    private List<Set<String>> parameterDebugNames = new ArrayList<>();
 
     public RegularMethodNode(MethodReference reference) {
         super(reference);
@@ -44,7 +45,7 @@ public class RegularMethodNode extends MethodNode {
         return variables;
     }
 
-    public List<String> getParameterDebugNames() {
+    public List<Set<String>> getParameterDebugNames() {
         return parameterDebugNames;
     }
 

teavm-core/src/main/java/org/teavm/model/Program.java

@@ -35,8 +35,8 @@ public class Program implements ProgramReader {
         return block;
     }
 
-    public Variable createVariable(String debugName) {
+    public Variable createVariable() {
-        Variable variable = new Variable(this, debugName);
+        Variable variable = new Variable(this);
         variable.setIndex(variables.size());
         variables.add(variable);
         variable.setRegister(lastUsedRegister++);

teavm-core/src/main/java/org/teavm/model/Variable.java

@@ -15,6 +15,10 @@
  */
 package org.teavm.model;
 
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
 /**
  *
  * @author Alexey Andreev
@@ -23,11 +27,11 @@ public class Variable implements VariableReader {
     private Program program;
     private int index;
     private int register;
-    private String debugName;
+    private Set<String> debugNames;
 
-    Variable(Program program, String debugName) {
+    Variable(Program program) {
         this.program = program;
-        this.debugName = debugName;
+        this.debugNames = new HashSet<>();
     }
 
     @Override
@@ -57,25 +61,12 @@ public class Variable implements VariableReader {
         this.register = register;
     }
 
+    public Set<String> getDebugNames() {
+        return debugNames;
+    }
+
     @Override
-    public String getDebugName() {
+    public Set<String> readDebugNames() {
-        return debugName;
+        return Collections.unmodifiableSet(debugNames);
-    }
-
-    public void setDebugName(String debugName) {
-        this.debugName = debugName;
-    }
-
-    public void mergeDebugName(String otherDebugName) {
-        if (otherDebugName == null) {
-            return;
-        }
-        String[] parts = debugName != null ? debugName.split("\\|") : new String[0];
-        for (String part : parts) {
-            if (otherDebugName.equals(part)) {
-                return;
-            }
-        }
-        debugName = debugName != null ? debugName + "|" + otherDebugName : otherDebugName;
     }
 }

teavm-core/src/main/java/org/teavm/model/VariableReader.java

@@ -15,6 +15,8 @@
  */
 package org.teavm.model;
 
+import java.util.Set;
+
 /**
  *
  * @author Alexey Andreev
@@ -24,7 +26,7 @@ public interface VariableReader {
 
     ProgramReader getProgram();
 
-    String getDebugName();
+    Set<String> readDebugNames();
 
     int getRegister();
 }

teavm-core/src/main/java/org/teavm/model/util/ListingBuilder.java

@@ -29,8 +29,16 @@ public class ListingBuilder {
         for (int i = 0; i < program.variableCount(); ++i) {
             sb.append(prefix).append("var @").append(i);
             VariableReader var = program.variableAt(i);
-            if (var.getDebugName() != null) {
+            if (!var.readDebugNames().isEmpty()) {
-                sb.append(" as ").append(var.getDebugName());
+                sb.append(" as ");
+                boolean first = true;
+                for (String debugName : var.readDebugNames()) {
+                    if (!first) {
+                        sb.append(", ");
+                    }
+                    first = false;
+                    sb.append(debugName);
+                }
             }
             sb.append('\n');
         }

teavm-core/src/main/java/org/teavm/model/util/ProgramUtils.java

@@ -73,7 +73,8 @@ public final class ProgramUtils {
         InstructionCopyReader insnCopier = new InstructionCopyReader();
         insnCopier.programCopy = copy;
         for (int i = 0; i < program.variableCount(); ++i) {
-            copy.createVariable(program.variableAt(i).getDebugName());
+            Variable var = copy.createVariable();
+            var.getDebugNames().addAll(program.variableAt(i).readDebugNames());
         }
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             copy.createBasicBlock();

teavm-core/src/main/java/org/teavm/model/util/RegisterAllocator.java

@@ -97,7 +97,7 @@ public class RegisterAllocator {
         final Phi phi = incoming.getPhi();
         Program program = phi.getBasicBlock().getProgram();
         AssignInstruction copyInstruction = new AssignInstruction();
-        Variable firstCopy = program.createVariable(incoming.getValue().getDebugName());
+        Variable firstCopy = program.createVariable();
         copyInstruction.setReceiver(firstCopy);
         copyInstruction.setAssignee(incoming.getValue());
         BasicBlock source = blockMap.get(incoming.getSource());
@@ -214,14 +214,14 @@ public class RegisterAllocator {
                         varMap[tryCatch.getExceptionVariable().getIndex()]));
             }
         }
-        String[] originalNames = new String[program.variableCount()];
+        String[][] originalNames = new String[program.variableCount()][];
         for (int i = 0; i < program.variableCount(); ++i) {
             Variable var = program.variableAt(i);
-            originalNames[i] = var.getDebugName();
+            originalNames[i] = var.getDebugNames().toArray(new String[0]);
-            var.setDebugName(null);
+            var.getDebugNames().clear();
         }
         for (int i = 0; i < program.variableCount(); ++i) {
-            program.variableAt(varMap[i]).mergeDebugName(originalNames[i]);
+            program.variableAt(varMap[i]).getDebugNames().addAll(Arrays.asList(originalNames[i]));
         }
     }
 

teavm-core/src/main/java/org/teavm/optimization/GlobalValueNumbering.java

@@ -114,7 +114,7 @@ public class GlobalValueNumbering implements MethodOptimization {
             if (map[i] != i) {
                 Variable var = program.variableAt(i);
                 Variable mapVar = program.variableAt(map[i]);
-                mapVar.mergeDebugName(var.getDebugName());
+                mapVar.getDebugNames().addAll(var.getDebugNames());
                 program.deleteVariable(i);
             }
         }

teavm-core/src/main/java/org/teavm/optimization/LoopInvariantMotion.java

@@ -179,7 +179,7 @@ public class LoopInvariantMotion implements MethodOptimization {
                     phi.getIncomings().remove(j--);
                     if (preheaderPhi == null) {
                         preheaderPhi = new Phi();
-                        preheaderPhi.setReceiver(program.createVariable(null));
+                        preheaderPhi.setReceiver(program.createVariable());
                         preheader.getPhis().add(preheaderPhi);
                     }
                     preheaderPhi.getIncomings().add(incoming);
@@ -391,7 +391,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(ClassConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             ClassConstantInstruction copy = new ClassConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -400,7 +401,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(NullConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             NullConstantInstruction copy = new NullConstantInstruction();
             copy.setReceiver(var);
             this.copy = copy;
@@ -408,7 +410,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(IntegerConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             IntegerConstantInstruction copy = new IntegerConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -417,7 +420,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(LongConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             LongConstantInstruction copy = new LongConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -426,7 +430,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(FloatConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             FloatConstantInstruction copy = new FloatConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -435,7 +440,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(DoubleConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             DoubleConstantInstruction copy = new DoubleConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);
@@ -444,7 +450,8 @@ public class LoopInvariantMotion implements MethodOptimization {
 
         @Override
         public void visit(StringConstantInstruction insn) {
-            var = program.createVariable(insn.getReceiver().getDebugName());
+            var = program.createVariable();
+            var.getDebugNames().addAll(insn.getReceiver().getDebugNames());
             StringConstantInstruction copy = new StringConstantInstruction();
             copy.setConstant(insn.getConstant());
             copy.setReceiver(var);

teavm-core/src/main/java/org/teavm/parsing/Parser.java

@@ -44,7 +44,7 @@ public final class Parser {
         method.setProgram(program);
         parseAnnotations(method.getAnnotations(), node.visibleAnnotations, node.invisibleAnnotations);
         while (program.variableCount() <= method.parameterCount()) {
-            program.createVariable(null);
+            program.createVariable();
         }
         return method;
     }

teavm-core/src/main/java/org/teavm/parsing/ProgramParser.java

@@ -115,7 +115,7 @@ public class ProgramParser implements VariableDebugInformation {
         }
         int signatureVars = countSignatureVariables(method.desc);
         while (program.variableCount() <= signatureVars) {
-            program.createVariable(null);
+            program.createVariable();
         }
         return program;
     }
@@ -334,7 +334,7 @@ public class ProgramParser implements VariableDebugInformation {
 
     private Variable getVariable(int index) {
         while (index >= program.variableCount()) {
-            program.createVariable(null);
+            program.createVariable();
         }
         return program.variableAt(index);
     }

teavm-core/src/main/java/org/teavm/parsing/SSATransformer.java

@@ -140,17 +140,19 @@ public class SSATransformer {
             processed[currentBlock.getIndex()] = true;
             variableMap = Arrays.copyOf(task.variables, task.variables.length);
             for (Phi phi : currentBlock.getPhis()) {
-                Variable var = program.createVariable(phi.getReceiver().getDebugName());
+                Variable var = program.createVariable();
+                var.getDebugNames().addAll(phi.getReceiver().getDebugNames());
                 variableMap[phi.getReceiver().getIndex()] = var;
                 phi.setReceiver(var);
             }
             if (!caughtBlocks.get(currentBlock.getIndex()).isEmpty()) {
                 Phi phi = new Phi();
-                phi.setReceiver(program.createVariable(null));
+                phi.setReceiver(program.createVariable());
                 for (TryCatchBlock tryCatch : caughtBlocks.get(currentBlock.getIndex())) {
                     variableMap[tryCatch.getExceptionVariable().getIndex()] = phi.getReceiver();
-                    tryCatch.setExceptionVariable(program.createVariable(
+                    Set<String> debugNames = tryCatch.getExceptionVariable().getDebugNames();
-                            tryCatch.getExceptionVariable().getDebugName()));
+                    tryCatch.setExceptionVariable(program.createVariable());
+                    tryCatch.getExceptionVariable().getDebugNames().addAll(debugNames);
                     Incoming incoming = new Incoming();
                     incoming.setSource(tryCatch.getProtectedBlock());
                     incoming.setValue(tryCatch.getExceptionVariable());
@@ -182,7 +184,7 @@ public class SSATransformer {
                         incoming.setSource(currentBlock);
                         incoming.setValue(var);
                         phi.getIncomings().add(incoming);
-                        phi.getReceiver().mergeDebugName(var.getDebugName());
+                        phi.getReceiver().getDebugNames().addAll(var.getDebugNames());
                     }
                 }
             }
@@ -219,7 +221,7 @@ public class SSATransformer {
     }
 
     private Variable define(Variable var) {
-        Variable result = program.createVariable(null);
+        Variable result = program.createVariable();
         variableMap[var.getIndex()] = result;
         return result;
     }
@@ -231,7 +233,7 @@ public class SSATransformer {
         }
         String debugName = variableDebugMap.get(var.getIndex());
         if (debugName != null) {
-            mappedVar.setDebugName(debugName);
+            mappedVar.getDebugNames().add(debugName);
         }
         return mappedVar;
     }

teavm-eclipse-plugin/META-INF/MANIFEST.MF

@@ -5,18 +5,18 @@ Bundle-SymbolicName: teavm-eclipse-plugin;singleton:=true
 Bundle-Version: 0.2.0.qualifer
 Bundle-Vendor: Alexey Andreev <konsoletyper@gmail.com>
 Bundle-RequiredExecutionEnvironment: JavaSE-1.7
-Require-Bundle: org.eclipse.core.runtime;bundle-version="3.9.0",
+Require-Bundle: org.eclipse.core.runtime;bundle-version="[3.8.0,4.0)",
- org.eclipse.debug.core;bundle-version="3.8.0",
+ org.eclipse.debug.core;bundle-version="[3.7.0,4.0)",
- org.eclipse.debug.ui;bundle-version="3.9.0",
+ org.eclipse.debug.ui;bundle-version="[3.8.0,4.0)",
- org.eclipse.swt;bundle-version="3.102.0",
+ org.eclipse.swt;bundle-version="[3.8.1,4.0)",
- org.eclipse.ui;bundle-version="3.105.0",
+ org.eclipse.ui;bundle-version="[3.7.1,4.0)",
- org.eclipse.jdt.debug;bundle-version="3.8.0",
+ org.eclipse.jdt.debug;bundle-version="[3.7.101,4.0.0)",
- org.eclipse.jdt.debug.ui;bundle-version="3.6.200",
+ org.eclipse.jdt.debug.ui;bundle-version="[3.6.100,4.0.0)",
- org.eclipse.jdt.core;bundle-version="3.9.2",
+ org.eclipse.jdt.core;bundle-version="[3.8.3,4.0.0)",
- org.eclipse.jdt.launching;bundle-version="3.7.1",
+ org.eclipse.jdt.launching;bundle-version="[3.6.1,4.0.0)",
- org.eclipse.ui.editors;bundle-version="3.8.100",
+ org.eclipse.ui.editors;bundle-version="[3.8.0,4.0.0)",
- org.eclipse.ui.ide;bundle-version="3.9.0",
+ org.eclipse.ui.ide;bundle-version="[3.8.2,4.0.0)",
- org.eclipse.jdt.ui;bundle-version="3.9.2"
+ org.eclipse.jdt.ui;bundle-version="[3.8.2,4.0.0)"
 Bundle-ClassPath: .,
  lib/asm-5.0.1.jar,
  lib/asm-commons-5.0.1.jar,

teavm-html4j/src/main/java/org/teavm/html4j/JCLHacks.java

@@ -44,13 +44,13 @@ public class JCLHacks implements ClassHolderTransformer {
         MethodHolder method = new MethodHolder(desc);
         Program program = new Program();
         for (int i = 0; i < desc.parameterCount(); ++i) {
-            program.createVariable(null);
+            program.createVariable();
         }
         if (!staticMethod) {
-            program.createVariable(null);
+            program.createVariable();
         }
-        program.createVariable(null);
+        program.createVariable();
-        Variable var = program.createVariable(null);
+        Variable var = program.createVariable();
         BasicBlock block = program.createBasicBlock();
         ConstructInstruction cons = new ConstructInstruction();
         cons.setType("java.lang.SecurityException");
@@ -75,8 +75,8 @@ public class JCLHacks implements ClassHolderTransformer {
     private MethodHolder createThreadSleep() {
         MethodHolder method = new MethodHolder("sleep", ValueType.LONG, ValueType.VOID);
         Program program = new Program();
-        program.createVariable(null);
+        program.createVariable();
-        program.createVariable(null);
+        program.createVariable();
         BasicBlock block = program.createBasicBlock();
         ExitInstruction exit = new ExitInstruction();
         block.getInstructions().add(exit);

teavm-jso/src/main/java/org/teavm/jso/plugin/JavascriptNativeProcessor.java

@@ -81,7 +81,7 @@ class JavascriptNativeProcessor {
                     if (isProperGetter(method.getDescriptor())) {
                         String propertyName = method.getName().charAt(0) == 'i' ? cutPrefix(method.getName(), 2) :
                                 cutPrefix(method.getName(), 3);
-                        Variable result = invoke.getReceiver() != null ? program.createVariable(null) : null;
+                        Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
                         addPropertyGet(propertyName, invoke.getInstance(), result);
                         if (result != null) {
                             result = unwrap(result, method.getResultType());
@@ -96,7 +96,7 @@ class JavascriptNativeProcessor {
                     }
                 } else if (method.getAnnotations().get(JSIndexer.class.getName()) != null) {
                     if (isProperGetIndexer(method.getDescriptor())) {
-                        Variable result = invoke.getReceiver() != null ? program.createVariable(null) : null;
+                        Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
                         addIndexerGet(invoke.getInstance(), wrap(invoke.getArguments().get(0),
                                 method.parameterType(0)), result);
                         if (result != null) {
@@ -143,7 +143,7 @@ class JavascriptNativeProcessor {
                                     "a proper native JavaScript method or constructor declaration");
                         }
                     }
-                    Variable result = invoke.getReceiver() != null ? program.createVariable(null) : null;
+                    Variable result = invoke.getReceiver() != null ? program.createVariable() : null;
                     InvokeInstruction newInvoke = new InvokeInstruction();
                     ValueType[] signature = new ValueType[method.parameterCount() + 3];
                     Arrays.fill(signature, ValueType.object(JSObject.class.getName()));
@@ -226,7 +226,7 @@ class JavascriptNativeProcessor {
     }
 
     private Variable addString(String str) {
-        Variable var = program.createVariable(null);
+        Variable var = program.createVariable();
         StringConstantInstruction nameInsn = new StringConstantInstruction();
         nameInsn.setReceiver(var);
         nameInsn.setConstant(str);
@@ -261,7 +261,7 @@ class JavascriptNativeProcessor {
             } else if (className.equals("java.lang.String")) {
                 return unwrap(var, "unwrapString", ValueType.object("java.lang.String"));
             } else {
-                Variable result = program.createVariable(null);
+                Variable result = program.createVariable();
                 CastInstruction castInsn = new CastInstruction();
                 castInsn.setReceiver(result);
                 castInsn.setValue(var);
@@ -274,7 +274,7 @@ class JavascriptNativeProcessor {
     }
 
     private Variable unwrap(Variable var, String methodName, ValueType resultType) {
-        Variable result = program.createVariable(null);
+        Variable result = program.createVariable();
         InvokeInstruction insn = new InvokeInstruction();
         insn.setMethod(new MethodReference(JS.class.getName(), methodName, ValueType.object(JSObject.class.getName()),
                 resultType));
@@ -301,7 +301,7 @@ class JavascriptNativeProcessor {
             throw new RuntimeException("Wrong functor: " + type.getName());
         }
         String name = type.getMethods().iterator().next().getName();
-        Variable functor = program.createVariable(null);
+        Variable functor = program.createVariable();
         Variable nameVar = addStringWrap(addString(name));
         InvokeInstruction insn = new InvokeInstruction();
         insn.setMethod(new MethodReference(JS.class.getName(), "function",
@@ -321,7 +321,7 @@ class JavascriptNativeProcessor {
                 return var;
             }
         }
-        Variable result = program.createVariable(null);
+        Variable result = program.createVariable();
         InvokeInstruction insn = new InvokeInstruction();
         insn.setMethod(new MethodReference(JS.class.getName(), "wrap", type,
                 ValueType.object(JSObject.class.getName())));

teavm-platform/src/main/java/org/teavm/platform/plugin/ResourceProgramTransformer.java

@@ -131,7 +131,7 @@ class ResourceProgramTransformer {
         } else if (type instanceof ValueType.Object) {
             switch (((ValueType.Object)type).getClassName()) {
                 case "java.lang.String": {
-                    Variable resultVar = insn.getProgram().createVariable(null);
+                    Variable resultVar = insn.getProgram().createVariable();
                     getProperty(insn, property, instructions, resultVar);
                     InvokeInstruction castInvoke = new InvokeInstruction();
                     castInvoke.setType(InvocationType.SPECIAL);
@@ -143,7 +143,7 @@ class ResourceProgramTransformer {
                     return instructions;
                 }
                 default: {
-                    Variable resultVar = insn.getProgram().createVariable(null);
+                    Variable resultVar = insn.getProgram().createVariable();
                     getProperty(insn, property, instructions, resultVar);
                     CastInstruction castInsn = new CastInstruction();
                     castInsn.setReceiver(insn.getReceiver());
@@ -159,7 +159,7 @@ class ResourceProgramTransformer {
 
     private void getProperty(InvokeInstruction insn, String property, List<Instruction> instructions,
             Variable resultVar) {
-        Variable nameVar = program.createVariable(null);
+        Variable nameVar = program.createVariable();
         StringConstantInstruction nameInsn = new StringConstantInstruction();
         nameInsn.setConstant(property);
         nameInsn.setReceiver(nameVar);
@@ -176,7 +176,7 @@ class ResourceProgramTransformer {
 
     private void getAndCastProperty(InvokeInstruction insn, String property, List<Instruction> instructions,
             Class<?> primitive) {
-        Variable resultVar = program.createVariable(null);
+        Variable resultVar = program.createVariable();
         getProperty(insn, property, instructions, resultVar);
         InvokeInstruction castInvoke = new InvokeInstruction();
         castInvoke.setType(InvocationType.SPECIAL);
@@ -220,7 +220,7 @@ class ResourceProgramTransformer {
         } else if (type instanceof ValueType.Object) {
             switch (((ValueType.Object)type).getClassName()) {
                 case "java.lang.String": {
-                    Variable castVar = insn.getProgram().createVariable(null);
+                    Variable castVar = insn.getProgram().createVariable();
                     InvokeInstruction castInvoke = new InvokeInstruction();
                     castInvoke.setType(InvocationType.SPECIAL);
                     castInvoke.setMethod(new MethodReference(ResourceAccessor.class, "castFromString",
@@ -242,7 +242,7 @@ class ResourceProgramTransformer {
 
     private void setProperty(InvokeInstruction insn, String property, List<Instruction> instructions,
             Variable valueVar) {
-        Variable nameVar = program.createVariable(null);
+        Variable nameVar = program.createVariable();
         StringConstantInstruction nameInsn = new StringConstantInstruction();
         nameInsn.setConstant(property);
         nameInsn.setReceiver(nameVar);
@@ -259,7 +259,7 @@ class ResourceProgramTransformer {
 
     private void castAndSetProperty(InvokeInstruction insn, String property, List<Instruction> instructions,
             Class<?> primitive) {
-        Variable castVar = program.createVariable(null);
+        Variable castVar = program.createVariable();
         InvokeInstruction castInvoke = new InvokeInstruction();
         castInvoke.setType(InvocationType.SPECIAL);
         String primitiveCapitalized = primitive.getName();