wasm gc: trying to fix issues with array covariance

core/src/main/java/org/teavm/ast/Expr.java

@@ -22,9 +22,18 @@ import org.teavm.model.*;
 
 public abstract class Expr implements Cloneable {
     private TextLocation location;
+    private int variableIndex = -1;
 
     public abstract void acceptVisitor(ExprVisitor visitor);
 
+    public int getVariableIndex() {
+        return variableIndex;
+    }
+
+    public void setVariableIndex(int variableIndex) {
+        this.variableIndex = variableIndex;
+    }
+
     @Override
     public Expr clone() {
         return clone(new HashMap<>());
@@ -41,6 +50,7 @@ public abstract class Expr implements Cloneable {
     public static Expr var(int index) {
         VariableExpr expr = new VariableExpr();
         expr.setIndex(index);
+        expr.setVariableIndex(index);
         return expr;
     }
 

core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java

@@ -211,6 +211,7 @@ class StatementGenerator implements InstructionVisitor {
     public void visit(CastInstruction insn) {
         CastExpr expr = new CastExpr();
         expr.setLocation(insn.getLocation());
+        expr.setVariableIndex(insn.getReceiver().getIndex());
         expr.setValue(Expr.var(insn.getValue().getIndex()));
         expr.setTarget(insn.getTargetType());
         assign(expr, insn.getReceiver());
@@ -219,6 +220,8 @@ class StatementGenerator implements InstructionVisitor {
     @Override
     public void visit(CastNumberInstruction insn) {
         PrimitiveCastExpr expr = new PrimitiveCastExpr();
+        expr.setLocation(insn.getLocation());
+        expr.setVariableIndex(insn.getReceiver().getIndex());
         expr.setSource(mapOperandType(insn.getSourceType()));
         expr.setTarget(mapOperandType(insn.getTargetType()));
         expr.setValue(Expr.var(insn.getValue().getIndex()));
@@ -495,6 +498,7 @@ class StatementGenerator implements InstructionVisitor {
         }
         AssignmentStatement stmt;
         if (insn.getReceiver() != null) {
+            invocationExpr.setVariableIndex(insn.getReceiver().getIndex());
             stmt = Statement.assign(Expr.var(insn.getReceiver().getIndex()), invocationExpr);
         } else {
             stmt = Statement.assign(null, invocationExpr);
@@ -518,6 +522,8 @@ class StatementGenerator implements InstructionVisitor {
 
     private void assign(Expr source, Variable target) {
         AssignmentStatement stmt = Statement.assign(Expr.var(target.getIndex()), source);
+        source.setLocation(currentLocation);
+        source.setVariableIndex(target.getIndex());
         stmt.setLocation(currentLocation);
         statements.add(stmt);
     }
@@ -647,7 +653,6 @@ class StatementGenerator implements InstructionVisitor {
         if (insn.getArray() != null) {
             expr.setArray(Expr.var(insn.getArray().getIndex()));
         }
-        expr.setLocation(insn.getLocation());
         assign(expr, insn.getReceiver());
     }
 }

core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java

@@ -190,6 +190,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
                         Expr result = BinaryExpr.binary(expr.getOperation(), comparison.getType(),
                                 comparison.getFirstOperand(), comparison.getSecondOperand());
                         result.setLocation(comparison.getLocation());
+                        result.setVariableIndex(comparison.getVariableIndex());
                         if (invert) {
                             result = ExprOptimizer.invert(result);
                         }
@@ -294,6 +295,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
                 ConstantExpr constantExpr = new ConstantExpr();
                 constantExpr.setValue(constants[index]);
                 constantExpr.setLocation(expr.getLocation());
+                constantExpr.setVariableIndex(expr.getVariableIndex());
                 resultExpr = constantExpr;
                 return;
             }
@@ -483,6 +485,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
         args = Arrays.copyOfRange(args, 1, args.length);
         InvocationExpr constructrExpr = Expr.constructObject(expr.getMethod(), args);
         constructrExpr.setLocation(expr.getLocation());
+        constructrExpr.setVariableIndex(constructed.getVariableIndex());
         assignment.setRightValue(constructrExpr);
         readFrequencies[var.getIndex()]--;
         return true;
@@ -823,6 +826,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
     private void applyArrayOptimization(ArrayOptimization optimization) {
         AssignmentStatement assign = (AssignmentStatement) resultSequence.get(optimization.index);
         ArrayFromDataExpr arrayFromData = new ArrayFromDataExpr();
+        arrayFromData.setVariableIndex(optimization.array.getVariableIndex());
         arrayFromData.setLocation(optimization.array.getLocation());
         arrayFromData.setType(optimization.array.getType());
         arrayFromData.getData().addAll(optimization.elements);
@@ -1096,6 +1100,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
             AssignmentStatement assignment = new AssignmentStatement();
             assignment.setLocation(conditionalExpr.getLocation());
             VariableExpr lhs = new VariableExpr();
+            lhs.setVariableIndex(firstLhs.getIndex());
             lhs.setIndex(firstLhs.getIndex());
             assignment.setLeftValue(lhs);
             assignment.setRightValue(conditionalExpr);
@@ -1166,6 +1171,7 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
                         if (statement.getCondition() != null) {
                             Expr newCondition = Expr.binary(BinaryOperation.AND, null, statement.getCondition(),
                                     ExprOptimizer.invert(cond.getCondition()));
+                            newCondition.setVariableIndex(statement.getCondition().getVariableIndex());
                             newCondition.setLocation(statement.getCondition().getLocation());
                             statement.setCondition(newCondition);
                         } else {

core/src/main/java/org/teavm/backend/wasm/generate/gc/classes/WasmGCClassGenerator.java

@@ -470,7 +470,7 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
         if (type instanceof ValueType.Object) {
             fillClassFields(fields, ((ValueType.Object) type).getClassName());
         } else if (type instanceof ValueType.Array) {
-            fillArrayField(classInfo, ((ValueType.Array) type).getItemType());
+            fillArrayFields(classInfo, ((ValueType.Array) type).getItemType());
         }
     }
 
@@ -516,8 +516,37 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
         }
     }
 
-    private void fillArrayField(WasmGCClassInfo classInfo, ValueType elementType) {
+    private void fillArrayFields(WasmGCClassInfo classInfo, ValueType elementType) {
-        var wasmArray = new WasmArray(null, () -> typeMapper.mapStorageType(elementType));
+        WasmStorageType wasmElementType;
+        if (elementType instanceof ValueType.Primitive) {
+            switch (((ValueType.Primitive) elementType).getKind()) {
+                case BOOLEAN:
+                case BYTE:
+                    wasmElementType = WasmStorageType.INT8;
+                    break;
+                case SHORT:
+                case CHARACTER:
+                    wasmElementType = WasmStorageType.INT16;
+                    break;
+                case INTEGER:
+                    wasmElementType = WasmType.INT32.asStorage();
+                    break;
+                case LONG:
+                    wasmElementType = WasmType.INT64.asStorage();
+                    break;
+                case FLOAT:
+                    wasmElementType = WasmType.FLOAT32.asStorage();
+                    break;
+                case DOUBLE:
+                    wasmElementType = WasmType.FLOAT64.asStorage();
+                    break;
+                default:
+                    throw new IllegalArgumentException();
+            }
+        } else {
+            wasmElementType = WasmType.Reference.STRUCT.asStorage();
+        }
+        var wasmArray = new WasmArray(null, wasmElementType);
         module.types.add(wasmArray);
         classInfo.structure.getFields().add(wasmArray.getReference().asStorage());
         classInfo.array = wasmArray;

core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCGenerationVisitor.java

@@ -23,6 +23,7 @@ import org.teavm.ast.InvocationExpr;
 import org.teavm.ast.QualificationExpr;
 import org.teavm.ast.SubscriptExpr;
 import org.teavm.ast.UnwrapArrayExpr;
+import org.teavm.backend.wasm.gc.PreciseTypeInference;
 import org.teavm.backend.wasm.generate.common.methods.BaseWasmGenerationVisitor;
 import org.teavm.backend.wasm.generate.gc.classes.WasmGCClassInfoProvider;
 import org.teavm.backend.wasm.model.WasmArray;
@@ -63,12 +64,14 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
     private WasmGCGenerationContext context;
     private WasmGCGenerationUtil generationUtil;
     private WasmType expectedType;
+    private PreciseTypeInference types;
 
     public WasmGCGenerationVisitor(WasmGCGenerationContext context, MethodReference currentMethod,
-            WasmFunction function, int firstVariable, boolean async) {
+            WasmFunction function, int firstVariable, boolean async, PreciseTypeInference types) {
         super(context, currentMethod, function, firstVariable, async);
         this.context = context;
         generationUtil = new WasmGCGenerationUtil(context.classInfoProvider(), tempVars);
+        this.types = types;
     }
 
     @Override
@@ -384,6 +387,12 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
         }
         arrayGet.setLocation(expr.getLocation());
         result = arrayGet;
+        if (expr.getType() == ArrayType.OBJECT && expr.getVariableIndex() >= 0) {
+            var targetType = types.typeOf(expr.getVariableIndex());
+            if (targetType != null) {
+                result = new WasmCast(result, (WasmType.Reference) mapType(targetType.valueType));
+            }
+        }
     }
 
     @Override

core/src/main/java/org/teavm/backend/wasm/generate/gc/methods/WasmGCMethodGenerator.java

@@ -250,7 +250,7 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
 
         addInitializerErase(method, function);
         var visitor = new WasmGCGenerationVisitor(getGenerationContext(), method.getReference(),
-                function, firstVar, false);
+                function, firstVar, false, typeInference);
         visitor.generate(ast.getBody(), function.getBody());
     }
 

core/src/main/java/org/teavm/backend/wasm/model/WasmStorageType.java

@@ -16,8 +16,8 @@
 package org.teavm.backend.wasm.model;
 
 public abstract class WasmStorageType {
-    private static final Packed INT16 = new Packed(WasmPackedType.INT16);
+    public static final Packed INT16 = new Packed(WasmPackedType.INT16);
-    private static final Packed INT8 = new Packed(WasmPackedType.INT8);
+    public static final Packed INT8 = new Packed(WasmPackedType.INT8);
 
     private WasmStorageType() {
     }

core/src/main/java/org/teavm/model/analysis/BaseTypeInference.java

@@ -238,12 +238,15 @@ public abstract class BaseTypeInference<T> {
         }
     }
 
-    @SuppressWarnings("unchecked")
     public T typeOf(Variable variable) {
-        ensure();
+        return typeOf(variable.getIndex());
-        return (T) types[variable.getIndex()];
     }
 
+    @SuppressWarnings("unchecked")
+    public T typeOf(int index) {
+        ensure();
+        return (T) types[index];
+    }
 
     protected abstract T mapType(ValueType type);