wasm: implement global variables

They aren't used by current Wasm BE yet, but will be used by future Wasm GC BE

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

@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.model;
+
+import java.util.Objects;
+import org.teavm.backend.wasm.model.expression.WasmExpression;
+
+public class WasmGlobal extends WasmEntity {
+    private String name;
+    private WasmType type;
+    private WasmExpression initialValue;
+
+    public WasmGlobal(String name, WasmType type, WasmExpression initialValue) {
+        this.name = name;
+        this.type = Objects.requireNonNull(type);
+        this.initialValue = Objects.requireNonNull(initialValue);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public WasmType getType() {
+        return type;
+    }
+
+    public void setType(WasmType type) {
+        this.type = Objects.requireNonNull(type);
+    }
+
+    public WasmExpression getInitialValue() {
+        return initialValue;
+    }
+
+    public void setInitialValue(WasmExpression initialValue) {
+        this.initialValue = Objects.requireNonNull(initialValue);
+    }
+}

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

@@ -31,6 +31,7 @@ public class WasmModule {
     private Map<String, WasmCustomSection> readonlyCustomSections = Collections.unmodifiableMap(customSections);
 
     public final WasmCollection<WasmFunction> functions = new WasmCollection<>();
+    public final WasmCollection<WasmGlobal> globals = new WasmCollection<>();
     public final WasmCollection<WasmCompositeType> types = new WasmCollection<>();
     public final WasmCollection<WasmTag> tags = new WasmCollection<>();
 

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmDefaultExpressionVisitor.java

@@ -94,6 +94,15 @@ public class WasmDefaultExpressionVisitor implements WasmExpressionVisitor {
         expression.getValue().acceptVisitor(this);
     }
 
+    @Override
+    public void visit(WasmGetGlobal expression) {
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        expression.getValue().acceptVisitor(this);
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         expression.getFirst().acceptVisitor(this);

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmExpressionVisitor.java

@@ -44,6 +44,10 @@ public interface WasmExpressionVisitor {
 
     void visit(WasmSetLocal expression);
 
+    void visit(WasmGetGlobal expression);
+
+    void visit(WasmSetGlobal expression);
+
     void visit(WasmIntBinary expression);
 
     void visit(WasmFloatBinary expression);

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmGetGlobal.java

@@ -0,0 +1,40 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.model.expression;
+
+import java.util.Objects;
+import org.teavm.backend.wasm.model.WasmGlobal;
+
+public class WasmGetGlobal extends WasmExpression {
+    private WasmGlobal global;
+
+    public WasmGetGlobal(WasmGlobal global) {
+        this.global = Objects.requireNonNull(global);
+    }
+
+    public WasmGlobal getGlobal() {
+        return global;
+    }
+
+    public void setGlobal(WasmGlobal global) {
+        this.global = Objects.requireNonNull(global);
+    }
+
+    @Override
+    public void acceptVisitor(WasmExpressionVisitor visitor) {
+        visitor.visit(this);
+    }
+}

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmReplacingExpressionVisitor.java

@@ -118,6 +118,15 @@ public class WasmReplacingExpressionVisitor implements WasmExpressionVisitor {
         expression.getValue().acceptVisitor(this);
     }
 
+    @Override
+    public void visit(WasmGetGlobal expression) {
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        expression.getValue().acceptVisitor(this);
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         expression.getFirst().acceptVisitor(this);

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmSetGlobal.java

@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2024 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.wasm.model.expression;
+
+import java.util.Objects;
+import org.teavm.backend.wasm.model.WasmGlobal;
+
+public class WasmSetGlobal extends WasmExpression {
+    private WasmGlobal global;
+    private WasmExpression value;
+
+    public WasmSetGlobal(WasmGlobal global, WasmExpression value) {
+        this.global = Objects.requireNonNull(global);
+        this.value = Objects.requireNonNull(value);
+    }
+
+    public WasmGlobal getGlobal() {
+        return global;
+    }
+
+    public void setGlobal(WasmGlobal global) {
+        this.global = Objects.requireNonNull(global);
+    }
+
+    public WasmExpression getValue() {
+        return value;
+    }
+
+    public void setValue(WasmExpression value) {
+        this.value = Objects.requireNonNull(value);
+    }
+
+    @Override
+    public void acceptVisitor(WasmExpressionVisitor visitor) {
+        visitor.visit(this);
+    }
+}

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

@@ -45,6 +45,7 @@ import org.teavm.backend.wasm.model.expression.WasmFloat32Constant;
 import org.teavm.backend.wasm.model.expression.WasmFloat64Constant;
 import org.teavm.backend.wasm.model.expression.WasmFloatBinary;
 import org.teavm.backend.wasm.model.expression.WasmFloatUnary;
+import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmGetLocal;
 import org.teavm.backend.wasm.model.expression.WasmIndirectCall;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
@@ -59,6 +60,7 @@ import org.teavm.backend.wasm.model.expression.WasmMemoryGrow;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
 import org.teavm.backend.wasm.model.expression.WasmReferencesEqual;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
+import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat32;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat64;
@@ -269,6 +271,23 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         popLocation();
     }
 
+    @Override
+    public void visit(WasmGetGlobal expression) {
+        pushLocation(expression);
+        writer.writeByte(0x23);
+        writer.writeLEB(module.globals.indexOf(expression.getGlobal()));
+        popLocation();
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        pushLocation(expression);
+        expression.getValue().acceptVisitor(this);
+        writer.writeByte(0x24);
+        writer.writeLEB(module.globals.indexOf(expression.getGlobal()));
+        popLocation();
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         pushLocation(expression);

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

@@ -22,6 +22,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.teavm.backend.wasm.model.WasmGlobal;
 import org.teavm.backend.wasm.model.WasmLocal;
 import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.backend.wasm.model.WasmNumType;
@@ -47,6 +48,7 @@ import org.teavm.backend.wasm.model.expression.WasmFloat64Constant;
 import org.teavm.backend.wasm.model.expression.WasmFloatBinary;
 import org.teavm.backend.wasm.model.expression.WasmFloatType;
 import org.teavm.backend.wasm.model.expression.WasmFloatUnary;
+import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmGetLocal;
 import org.teavm.backend.wasm.model.expression.WasmIndirectCall;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
@@ -62,6 +64,7 @@ import org.teavm.backend.wasm.model.expression.WasmMemoryGrow;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
 import org.teavm.backend.wasm.model.expression.WasmReferencesEqual;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
+import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat32;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat64;
@@ -366,6 +369,24 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         value = result;
     }
 
+    @Override
+    public void visit(WasmGetGlobal expression) {
+        value = new CExpression(getVariableName(expression.getGlobal()));
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        CExpression result = new CExpression();
+        requiredType = expression.getGlobal().getType();
+        expression.getValue().acceptVisitor(this);
+        result.getLines().addAll(value.getLines());
+
+        result.addLine(getVariableName(expression.getGlobal()) + " = " + value.getText() + ";",
+                expression.getLocation());
+
+        value = result;
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         WasmType type = requiredType;
@@ -1277,4 +1298,8 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         }
         return result;
     }
+
+    String getVariableName(WasmGlobal global) {
+        return "wasm_global_" + module.globals.indexOf(global);
+    }
 }

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

@@ -18,6 +18,7 @@ package org.teavm.backend.wasm.render;
 import java.util.HashMap;
 import java.util.Map;
 import org.teavm.backend.wasm.model.WasmCompositeType;
+import org.teavm.backend.wasm.model.WasmGlobal;
 import org.teavm.backend.wasm.model.WasmLocal;
 import org.teavm.backend.wasm.model.WasmModule;
 import org.teavm.backend.wasm.model.WasmNumType;
@@ -46,6 +47,7 @@ import org.teavm.backend.wasm.model.expression.WasmFloatBinaryOperation;
 import org.teavm.backend.wasm.model.expression.WasmFloatType;
 import org.teavm.backend.wasm.model.expression.WasmFloatUnary;
 import org.teavm.backend.wasm.model.expression.WasmFloatUnaryOperation;
+import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmGetLocal;
 import org.teavm.backend.wasm.model.expression.WasmIndirectCall;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
@@ -63,6 +65,7 @@ import org.teavm.backend.wasm.model.expression.WasmMemoryGrow;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
 import org.teavm.backend.wasm.model.expression.WasmReferencesEqual;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
+import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat32;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat64;
@@ -290,18 +293,32 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
 
     @Override
     public void visit(WasmGetLocal expression) {
-        open().append("get_local " + asString(expression.getLocal())).close();
+        open().append("local.get " + asString(expression.getLocal())).close();
     }
 
     @Override
     public void visit(WasmSetLocal expression) {
-        open().append("set_local " + asString(expression.getLocal())).line(expression.getValue()).close();
+        open().append("local.set " + asString(expression.getLocal())).line(expression.getValue()).close();
+    }
+
+    @Override
+    public void visit(WasmGetGlobal expression) {
+        open().append("global.get " + asString(expression.getGlobal())).close();
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        open().append("global.set " + asString(expression.getGlobal())).line(expression.getValue()).close();
     }
 
     private String asString(WasmLocal local) {
         return String.valueOf(local.getIndex());
     }
 
+    private String asString(WasmGlobal global) {
+        return global.getName() != null ? "$" + global.getName() : String.valueOf(module.globals.indexOf(global));
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         open().append(type(expression.getType()) + "." + operation(expression.getOperation()));

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

@@ -36,6 +36,7 @@ import org.teavm.backend.wasm.model.expression.WasmFloat64Constant;
 import org.teavm.backend.wasm.model.expression.WasmFloatBinary;
 import org.teavm.backend.wasm.model.expression.WasmFloatType;
 import org.teavm.backend.wasm.model.expression.WasmFloatUnary;
+import org.teavm.backend.wasm.model.expression.WasmGetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmGetLocal;
 import org.teavm.backend.wasm.model.expression.WasmIndirectCall;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
@@ -51,6 +52,7 @@ import org.teavm.backend.wasm.model.expression.WasmMemoryGrow;
 import org.teavm.backend.wasm.model.expression.WasmNullConstant;
 import org.teavm.backend.wasm.model.expression.WasmReferencesEqual;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
+import org.teavm.backend.wasm.model.expression.WasmSetGlobal;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat32;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat64;
@@ -136,6 +138,16 @@ public class WasmTypeInference implements WasmExpressionVisitor {
         result = null;
     }
 
+    @Override
+    public void visit(WasmGetGlobal expression) {
+        result = expression.getGlobal().getType();
+    }
+
+    @Override
+    public void visit(WasmSetGlobal expression) {
+        result = null;
+    }
+
     @Override
     public void visit(WasmIntBinary expression) {
         result = map(expression.getType());