Trying to preserve variable names after GVN

core/src/main/java/org/teavm/backend/wasm/render/WasmCRenderer.java

@@ -140,13 +140,13 @@ public class WasmCRenderer {
         line(functionDeclaration(function) + " {");
         indent();
 
+        WasmCRenderingVisitor visitor = new WasmCRenderingVisitor(function.getResult(), function.getModule());
         List<WasmLocal> variables = function.getLocalVariables().subList(function.getParameters().size(),
                 function.getLocalVariables().size());
         for (WasmLocal variable : variables) {
-            line(WasmCRenderingVisitor.mapType(variable.getType()) + " var_" + variable.getIndex() + ";");
+            line(WasmCRenderingVisitor.mapType(variable.getType()) + " " + visitor.getVariableName(variable) + ";");
         }
 
-        WasmCRenderingVisitor visitor = new WasmCRenderingVisitor(function.getResult(), function.getModule());
         List<WasmExpression> body = function.getBody();
         List<CLine> lines = new ArrayList<>();
         if (!body.isEmpty()) {

core/src/main/java/org/teavm/model/ClassHolderSource.java

@@ -42,6 +42,6 @@ public interface ClassHolderSource extends ClassReaderSource {
     }
 
     default Stream<MethodHolder> mutableOverridenMethods(MethodReference method) {
-        return overridenMethods(method).map(m -> (MethodHolder) m);
+        return overriddenMethods(method).map(m -> (MethodHolder) m);
     }
 }

core/src/main/java/org/teavm/model/ClassReaderSource.java

@@ -24,10 +24,6 @@ import java.util.Set;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
-/**
- *
- * @author Alexey Andreev
- */
 public interface ClassReaderSource {
     ClassReader get(String name);
 
@@ -104,7 +100,7 @@ public interface ClassReaderSource {
                 .findFirst().orElse(null);
     }
 
-    default Stream<MethodReader> overridenMethods(MethodReference method) {
+    default Stream<MethodReader> overriddenMethods(MethodReference method) {
         return getAncestorClasses(method.getClassName())
                 .map(cls -> cls.getMethod(method.getDescriptor()))
                 .filter(candidate -> candidate != null);

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

@@ -150,12 +150,20 @@ public class GlobalValueNumbering implements MethodOptimization {
             }
         }
 
+        String[] debugNames = new String[program.variableCount()];
+        for (int i = 0; i < program.variableCount(); ++i) {
+            debugNames[i] = program.variableAt(i).getDebugName();
+            program.variableAt(i).setDebugName(null);
+        }
         for (int i = 0; i < map.length; ++i) {
             if (map[i] != i) {
-                Variable var = program.variableAt(i);
                 Variable mapVar = program.variableAt(map[i]);
-                mapVar.setDebugName(var.getDebugName());
+                if (debugNames[i] != null && mapVar.getDebugName() == null) {
+                    mapVar.setDebugName(debugNames[i]);
+                }
                 program.deleteVariable(i);
+            } else {
+                program.variableAt(i).setDebugName(debugNames[i]);
             }
         }
 
@@ -165,7 +173,7 @@ public class GlobalValueNumbering implements MethodOptimization {
     }
 
     private void bind(int var, String value) {
-        String name = program.variableAt(var).getDebugName();
+        String name = program.variableAt(map[var]).getDebugName();
         if (name == null) {
             name = "";
         }

core/src/main/java/org/teavm/model/util/PhiUpdater.java

@@ -28,6 +28,7 @@ import java.util.stream.Collectors;
 import org.teavm.common.DominatorTree;
 import org.teavm.common.Graph;
 import org.teavm.common.GraphUtils;
+import org.teavm.common.IntegerArray;
 import org.teavm.model.BasicBlock;
 import org.teavm.model.Incoming;
 import org.teavm.model.Instruction;
@@ -88,6 +89,11 @@ public class PhiUpdater {
     private List<List<List<TryCatchJoint>>> synthesizedJoints = new ArrayList<>();
     private Variable[] originalExceptionVariables;
     private boolean[] usedDefinitions;
+    private IntegerArray variableToSourceMap = new IntegerArray(10);
+
+    public int getSourceVariable(int var) {
+        return variableToSourceMap.get(var);
+    }
 
     public void updatePhis(Program program, Variable[] arguments) {
         if (program.basicBlockCount() == 0) {
@@ -103,6 +109,9 @@ public class PhiUpdater {
             variableMap[i] = arguments[i];
             usedDefinitions[i] = true;
         }
+        for (int i = 0; i < program.variableCount(); ++i) {
+            variableToSourceMap.add(-1);
+        }
         phiMap = new Phi[program.basicBlockCount()][];
         phiIndexMap = new int[program.basicBlockCount()][];
         jointMap.clear();
@@ -201,7 +210,7 @@ public class PhiUpdater {
             for (Phi phi : synthesizedPhis.get(index)) {
                 Variable var = program.createVariable();
                 var.setDebugName(phi.getReceiver().getDebugName());
-                variableMap[phi.getReceiver().getIndex()] = var;
+                mapVariable(phi.getReceiver().getIndex(), var);
                 phi.setReceiver(var);
             }
             for (Phi phi : currentBlock.getPhis()) {
@@ -334,7 +343,7 @@ public class PhiUpdater {
         Variable original = var;
         var = introduce(var);
         propagateToTryCatch(original, var, old);
-        variableMap[original.getIndex()] = var;
+        mapVariable(original.getIndex(), var);
         return var;
     }
 
@@ -368,6 +377,14 @@ public class PhiUpdater {
         }
     }
 
+    private void mapVariable(int index, Variable var) {
+        variableMap[index] = var;
+        while (variableToSourceMap.size() <= var.getIndex()) {
+            variableToSourceMap.add(-1);
+        }
+        variableToSourceMap.set(var.getIndex(), index);
+    }
+
     private Variable introduce(Variable var) {
         if (!usedDefinitions[var.getIndex()]) {
             usedDefinitions[var.getIndex()] = true;

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

@@ -86,6 +86,8 @@ public class Parser {
         applyDebugNames(program, phiUpdater, programParser, argumentMapping);
 
         parseAnnotations(method.getAnnotations(), node.visibleAnnotations, node.invisibleAnnotations);
+        applyDebugNames(program, phiUpdater, programParser,
+                applySignature(program, method.getDescriptor().getParameterTypes()));
         while (program.variableCount() <= method.parameterCount()) {
             program.createVariable();
         }
@@ -100,7 +102,7 @@ public class Parser {
         return method;
     }
 
-    private void applyDebugNames(Program program, PhiUpdater phiUpdater, ProgramParser parser,
+    private static void applyDebugNames(Program program, PhiUpdater phiUpdater, ProgramParser parser,
             Variable[] argumentMapping) {
         if (program.basicBlockCount() == 0) {
             return;
@@ -130,14 +132,14 @@ public class Parser {
                 for (Map.Entry<Integer, String> debugName : debugNames.entrySet()) {
                     int receiver = varMap.getOrDefault(debugName.getKey(), -1);
                     if (receiver >= 0) {
-                        program.variableAt(receiver).getDebugNames().add(debugName.getValue());
+                        program.variableAt(receiver).setDebugName(debugName.getValue());
                     }
                 }
             }
         }
     }
 
-    private IntIntMap[] getBlockEntryVariableMappings(Program program, PhiUpdater phiUpdater,
+    private static IntIntMap[] getBlockEntryVariableMappings(Program program, PhiUpdater phiUpdater,
             Variable[] argumentMapping) {
         class Step {
             int node;
@@ -171,36 +173,29 @@ public class Parser {
             IntIntMap varMap = new IntIntOpenHashMap(step.varMap);
             BasicBlock block = program.basicBlockAt(node);
 
-            /*
-            for (TryCatchJoint joint : block.getTryCatchJoints()) {
-                int receiver = joint.getReceiver().getIndex();
-                int sourceVar = phiUpdater.getSourceVariable(receiver);
-                if (sourceVar >= 0) {
-                    varMap.put(sourceVar, receiver);
-                }
-            }
             for (Phi phi : block.getPhis()) {
                 int receiver = phi.getReceiver().getIndex();
+                /*
                 int sourceVar = phiUpdater.getSourceVariable(receiver);
                 if (sourceVar >= 0) {
                     varMap.put(sourceVar, receiver);
                 }
+                */
             }
-            */
 
             result[node] = new IntIntOpenHashMap(varMap);
 
-            /*
             for (Instruction insn : block.getInstructions()) {
                 insn.acceptVisitor(defExtractor);
                 for (Variable definedVar : defExtractor.getDefinedVariables()) {
+                    /*
                     int sourceVar = phiUpdater.getSourceVariable(definedVar.getIndex());
                     if (sourceVar >= 0) {
                         varMap.put(sourceVar, definedVar.getIndex());
                     }
+                    */
                 }
             }
-            */
 
             for (int successor : dom.outgoingEdges(node)) {
                 stack[top++] = new Step(successor, new IntIntOpenHashMap(varMap));