wasm gc: fix issues in generation of types, globals and some expressions

core/src/main/java/org/teavm/backend/wasm/generate/WasmGenerationVisitor.java

@@ -300,6 +300,11 @@ public class WasmGenerationVisitor extends BaseWasmGenerationVisitor {
         return new WasmInt32Constant(classGenerator.getClassPointer(type));
     }
 
+    @Override
+    protected WasmExpression nullLiteral() {
+        return new WasmInt32Constant(0);
+    }
+
     @Override
     public void visit(SubscriptExpr expr) {
         WasmExpression ptr = getArrayElementPointer(expr);

core/src/main/java/org/teavm/backend/wasm/generate/common/methods/BaseWasmGenerationVisitor.java

@@ -553,7 +553,7 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
     @Override
     public void visit(ConstantExpr expr) {
         if (expr.getValue() == null) {
-            result = new WasmInt32Constant(0);
+            result = nullLiteral();
         } else if (expr.getValue() instanceof Integer) {
             result = new WasmInt32Constant((Integer) expr.getValue());
         } else if (expr.getValue() instanceof Long) {
@@ -569,8 +569,11 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
         } else {
             throw new IllegalArgumentException("Constant unsupported: " + expr.getValue());
         }
+        result.setLocation(expr.getLocation());
     }
 
+    protected abstract WasmExpression nullLiteral();
+
     protected abstract WasmExpression stringLiteral(String s);
 
     protected abstract WasmExpression classLiteral(ValueType type);

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

@@ -335,8 +335,8 @@ public class WasmGCClassGenerator implements WasmGCClassInfoProvider, WasmGCInit
         var virtualTable = virtualTables.lookup(className);
         var structure = new WasmStructure(names.forClassClass(className));
         module.types.add(structure);
-        addVirtualTableFields(structure, virtualTable);
         fillClassFields(structure.getFields(), "java.lang.Class");
+        addVirtualTableFields(structure, virtualTable);
         return structure;
     }
 

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

@@ -17,6 +17,7 @@ package org.teavm.backend.wasm.generate.gc.methods;
 
 import java.util.List;
 import org.teavm.ast.ArrayType;
+import org.teavm.ast.BinaryExpr;
 import org.teavm.ast.Expr;
 import org.teavm.ast.InvocationExpr;
 import org.teavm.ast.QualificationExpr;
@@ -40,7 +41,11 @@ import org.teavm.backend.wasm.model.expression.WasmCast;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmGetLocal;
+import org.teavm.backend.wasm.model.expression.WasmIntType;
+import org.teavm.backend.wasm.model.expression.WasmIntUnary;
+import org.teavm.backend.wasm.model.expression.WasmIntUnaryOperation;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
+import org.teavm.backend.wasm.model.expression.WasmReferencesEqual;
 import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStructGet;
@@ -167,11 +172,45 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
         return new WasmGetGlobal(classConstant.getPointer());
     }
 
+    @Override
+    protected WasmExpression nullLiteral() {
+        return new WasmNullConstant(WasmType.Reference.STRUCT);
+    }
+
     @Override
     protected CallSiteIdentifier generateCallSiteId(TextLocation location) {
         return new SimpleCallSite();
     }
 
+    @Override
+    public void visit(BinaryExpr expr) {
+        if (expr.getType() == null) {
+            switch (expr.getOperation()) {
+                case EQUALS: {
+                    accept(expr.getFirstOperand());
+                    var first = result;
+                    accept(expr.getSecondOperand());
+                    var second = result;
+                    result = new WasmReferencesEqual(first, second);
+                    result.setLocation(expr.getLocation());
+                    return;
+                }
+                case NOT_EQUALS:
+                    accept(expr.getFirstOperand());
+                    var first = result;
+                    accept(expr.getSecondOperand());
+                    var second = result;
+                    result = new WasmReferencesEqual(first, second);
+                    result = new WasmIntUnary(WasmIntType.INT32, WasmIntUnaryOperation.EQZ, result);
+                    result.setLocation(expr.getLocation());
+                    return;
+                default:
+                    break;
+            }
+        }
+        super.visit(expr);
+    }
+
     @Override
     protected WasmExpression generateVirtualCall(WasmLocal instance, MethodReference method,
             List<WasmExpression> arguments) {

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

@@ -20,6 +20,7 @@ import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import org.teavm.common.Graph;
 import org.teavm.common.GraphUtils;
 
 public class WasmModule {
@@ -93,32 +94,70 @@ public class WasmModule {
     }
 
     public void prepareForRendering() {
-        prepareRecursiveTypes();
+        prepareTypes();
     }
 
-    private void prepareRecursiveTypes() {
+    private void prepareTypes() {
         var typeGraph = WasmTypeGraphBuilder.buildTypeGraph(types, types.size());
-        var newList = new ArrayList<WasmCompositeType>();
+        var sccs = GraphUtils.findStronglyConnectedComponents(typeGraph);
-        var typesInScc = new boolean[types.size()];
+        var sccStartNode = new int[types.size()];
-        for (var scc : GraphUtils.findStronglyConnectedComponents(typeGraph)) {
+        for (var i = 0; i < sccStartNode.length; ++i) {
+            sccStartNode[i] = i;
+        }
+        var sccsByIndex = new int[types.size()][];
+        for (var scc : sccs) {
+            sccsByIndex[scc[0]] = scc;
             var firstType = types.get(scc[0]);
             firstType.recursiveTypeCount = scc.length;
             for (var i = 0; i < scc.length; i++) {
                 var index = scc[i];
                 var type = types.get(index);
-                newList.add(type);
                 type.indexInRecursiveType = i;
-                typesInScc[index] = true;
+                sccStartNode[scc[i]] = sccStartNode[scc[0]];
             }
         }
-        for (var type : types) {
+
-            if (!typesInScc[type.index]) {
+        var sorting = new TypeSorting();
-                newList.add(type);
+        sorting.original = types;
-            }
+        sorting.graph = typeGraph;
+        sorting.visited = new boolean[types.size()];
+        sorting.sccMap = sccStartNode;
+        sorting.sccsByIndex = sccsByIndex;
+        for (var i = 0; i < types.size(); ++i) {
+            sorting.visit(i);
         }
+
         types.clear();
-        for (var type : newList) {
+        for (var type : sorting.sorted) {
             types.add(type);
         }
     }
+
+    private static class TypeSorting {
+        WasmCollection<WasmCompositeType> original;
+        Graph graph;
+        boolean[] visited;
+        int[] sccMap;
+        int[][] sccsByIndex;
+        List<WasmCompositeType> sorted = new ArrayList<>();
+
+        void visit(int typeIndex) {
+            typeIndex = sccMap[typeIndex];
+            if (visited[typeIndex]) {
+                return;
+            }
+            visited[typeIndex] = true;
+            for (var outgoing : graph.outgoingEdges(typeIndex)) {
+                visit(outgoing);
+            }
+            var scc = sccsByIndex[typeIndex];
+            if (scc == null) {
+                sorted.add(original.get(typeIndex));
+            } else {
+                for (var index : scc) {
+                    sorted.add(original.get(index));
+                }
+            }
+        }
+    }
 }

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

@@ -72,7 +72,7 @@ public abstract class WasmType {
         }
     }
 
-    public static final class SpecialReference extends WasmType {
+    public static final class SpecialReference extends Reference {
         public final SpecialReferenceKind kind;
 
         private SpecialReference(SpecialReferenceKind kind) {

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

@@ -38,6 +38,7 @@ public class WasmBinaryRenderer {
     private static final int SECTION_FUNCTION = 3;
     private static final int SECTION_TABLE = 4;
     private static final int SECTION_MEMORY = 5;
+    private static final int SECTION_GLOBAL = 6;
     private static final int SECTION_EXPORT = 7;
     private static final int SECTION_START = 8;
     private static final int SECTION_ELEMENT = 9;
@@ -88,6 +89,7 @@ public class WasmBinaryRenderer {
         renderTable(module);
         renderMemory(module);
         renderTags(module);
+        renderGlobals(module);
         renderExport(module);
         renderStart(module);
         renderElement(module);
@@ -205,6 +207,24 @@ public class WasmBinaryRenderer {
         writeSection(SECTION_MEMORY, "memory", section.getData());
     }
 
+    private void renderGlobals(WasmModule module) {
+        if (module.globals.isEmpty()) {
+            return;
+        }
+
+        var section = new WasmBinaryWriter();
+        var visitor = new WasmBinaryRenderingVisitor(section, module, null, null, 0);
+        section.writeLEB(module.globals.size());
+        for (var global : module.globals) {
+            section.writeType(global.getType(), module);
+            section.writeByte(1); // mutable
+            global.getInitialValue().acceptVisitor(visitor);
+            section.writeByte(0x0b);
+        }
+
+        writeSection(SECTION_GLOBAL, "global", section.getData());
+    }
+
     private void renderExport(WasmModule module) {
 
         // https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md#export-section

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

@@ -253,7 +253,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
     public void visit(WasmNullConstant expression) {
         pushLocation(expression);
         writer.writeByte(0xD0);
-        writeBlockType(expression.getType());
+        writer.writeHeapType(expression.getType(), module);
         popLocation();
     }
 
@@ -1146,7 +1146,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
     public void visit(WasmFunctionReference expression) {
         pushLocation(expression);
         writer.writeByte(0xd2);
-        writer.writeInt32(module.functions.indexOf(expression.getFunction()));
+        writer.writeLEB(module.functions.indexOf(expression.getFunction()));
         popLocation();
     }
 

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

@@ -41,7 +41,27 @@ public class WasmBinaryWriter {
         if (type instanceof WasmType.Number) {
             writeType(((WasmType.Number) type).number);
         } else if (type instanceof WasmType.SpecialReference) {
-            switch (((WasmType.SpecialReference) type).kind) {
+            writeSpecialHeapType(((WasmType.SpecialReference) type).kind);
+        } else if (type instanceof WasmType.CompositeReference) {
+            writeByte(0x63);
+            var composite = ((WasmType.CompositeReference) type).composite;
+            var index = module.types.indexOf(composite);
+            writeSignedLEB(index);
+        }
+    }
+
+    public void writeHeapType(WasmType.Reference type, WasmModule module) {
+        if (type instanceof WasmType.CompositeReference) {
+            var composite = ((WasmType.CompositeReference) type).composite;
+            var index = module.types.indexOf(composite);
+            writeSignedLEB(index);
+        } else {
+            writeSpecialHeapType(((WasmType.SpecialReference) type).kind);
+        }
+    }
+
+    private void writeSpecialHeapType(WasmType.SpecialReferenceKind type) {
+        switch (type) {
             case ANY:
                 writeByte(0x6e);
                 break;
@@ -58,14 +78,6 @@ public class WasmBinaryWriter {
                 writeByte(0x6a);
                 break;
         }
-        } else if (type instanceof WasmType.CompositeReference) {
-            writeByte(0x63);
-            var composite = ((WasmType.CompositeReference) type).composite;
-            var index = isRecursiveMember
-                    ? composite.getIndexInRecursiveType()
-                    : module.types.indexOf(composite);
-            writeSignedLEB(index);
-        }
     }
 
     public void writeType(WasmNumType type) {

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

@@ -75,7 +75,7 @@ public class WasmCompositeTypeBinaryRenderer implements WasmCompositeTypeVisitor
                     break;
             }
         } else {
-            section.writeType(storageType.asUnpackedType(), module);
+            section.writeType(storageType.asUnpackedType(), module, true);
         }
     }
 }