wasm gc: fix bugs related to casts and implement runtime method for converting date to string

classlib/src/main/java/org/teavm/classlib/java/util/TDate.java

@@ -373,7 +373,7 @@ public class TDate implements TComparable<TDate> {
     public String toString() {
         if (PlatformDetector.isC()) {
             return toStringC(value);
-        } else if (PlatformDetector.isWebAssembly()) {
+        } else if (PlatformDetector.isWebAssembly() || PlatformDetector.isWebAssemblyGC()) {
             return toStringWebAssembly(value);
         } else {
             return JSDate.create(value).stringValue();

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

@@ -170,6 +170,16 @@ public class WasmGenerationVisitor extends BaseWasmGenerationVisitor {
         return value;
     }
 
+    @Override
+    protected WasmType mapCastSourceType(WasmType type) {
+        return type;
+    }
+
+    @Override
+    protected boolean validateCastTypes(WasmType sourceType, WasmType targetType, TextLocation location) {
+        return true;
+    }
+
     @Override
     protected WasmExpression peekException() {
         return new WasmCall(context.functions().forStaticMethod(PEEK_EXCEPTION_METHOD));

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

@@ -1184,19 +1184,25 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
 
     @Override
     public void visit(CastExpr expr) {
-        if (expr.isWeak()) {
+        var wasmTargetType = (WasmType.CompositeReference) mapType(expr.getTarget());
-            acceptWithType(expr.getValue(), expr.getTarget());
-            result = generateCast(result, mapType(expr.getTarget()));
-            return;
-        }
-        var block = new WasmBlock(false);
-        var wasmTargetType = mapType(expr.getTarget());
-        block.setType(wasmTargetType);
-        block.setLocation(expr.getLocation());
-
         acceptWithType(expr.getValue(), expr.getTarget());
+        if (!expr.isWeak()) {
             result.acceptVisitor(typeInference);
             var wasmSourceType = typeInference.getResult();
+            if (wasmSourceType == null) {
+                return;
+            }
+
+            wasmSourceType = mapCastSourceType(wasmSourceType);
+
+            if (!validateCastTypes(wasmSourceType, wasmTargetType, expr.getLocation())) {
+                return;
+            }
+
+            var block = new WasmBlock(false);
+            block.setType(wasmSourceType);
+            block.setLocation(expr.getLocation());
+            acceptWithType(expr.getValue(), expr.getTarget());
             var valueToCast = exprCache.create(result, wasmSourceType, expr.getLocation(), block.getBody());
 
             var nullCheck = new WasmBranch(genIsNull(valueToCast.expr()), block);
@@ -1206,7 +1212,7 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
             var supertypeCall = generateInstanceOf(valueToCast.expr(), expr.getTarget());
 
             var breakIfPassed = new WasmBranch(supertypeCall, block);
-        breakIfPassed.setResult(generateCast(valueToCast.expr(), wasmTargetType));
+            breakIfPassed.setResult(valueToCast.expr());
             block.getBody().add(new WasmDrop(breakIfPassed));
 
             var callSiteId = generateCallSiteId(expr.getLocation());
@@ -1217,6 +1223,13 @@ public abstract class BaseWasmGenerationVisitor implements StatementVisitor, Exp
             valueToCast.release();
             result = block;
         }
+        result = generateCast(result, wasmTargetType);
+        result.setLocation(expr.getLocation());
+    }
+
+    protected abstract WasmType mapCastSourceType(WasmType type);
+
+    protected abstract boolean validateCastTypes(WasmType sourceType, WasmType targetType, TextLocation location);
 
     protected abstract WasmExpression generateCast(WasmExpression value, WasmType targetType);
 

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

@@ -222,7 +222,7 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
         }
         return new WasmNullConstant(type instanceof WasmType.Reference
                 ? (WasmType.Reference) type
-                : WasmType.Reference.STRUCT);
+                : context.classInfoProvider().getClassInfo("java.lang.Object").getType());
     }
 
     @Override
@@ -362,6 +362,39 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
         return new WasmCast(value, (WasmType.Reference) targetType);
     }
 
+    @Override
+    protected WasmType mapCastSourceType(WasmType type) {
+        if (!(type instanceof WasmType.CompositeReference)) {
+            return type;
+        }
+        var refType = (WasmType.CompositeReference) type;
+        return refType.isNullable() ? refType : refType.composite.getReference();
+    }
+
+    @Override
+    protected boolean validateCastTypes(WasmType sourceType, WasmType targetType, TextLocation location) {
+        if (!(sourceType instanceof WasmType.CompositeReference)
+                || !(targetType instanceof WasmType.CompositeReference)) {
+            return false;
+        }
+        var sourceRefType = (WasmType.CompositeReference) sourceType;
+        var targetRefType = (WasmType.CompositeReference) targetType;
+        if (sourceRefType.composite instanceof WasmStructure
+                && targetRefType.composite instanceof WasmStructure) {
+            var sourceStruct = (WasmStructure) sourceRefType.composite;
+            var targetStruct = (WasmStructure) targetRefType.composite;
+            if (targetStruct.isSupertypeOf(sourceStruct)) {
+                return false;
+            }
+            if (!sourceStruct.isSupertypeOf(targetStruct)) {
+                result = new WasmUnreachable();
+                result.setLocation(location);
+                return false;
+            }
+        }
+        return true;
+    }
+
     @Override
     protected boolean needsClassInitializer(String className) {
         return context.classInfoProvider().getClassInfo(className).getInitializerPointer() != null;
@@ -516,6 +549,11 @@ public class WasmGCGenerationVisitor extends BaseWasmGenerationVisitor {
 
             target.acceptVisitor(typeInference);
             var type = (WasmType.CompositeReference) typeInference.getResult();
+            if (type == null) {
+                result = new WasmUnreachable();
+                result.setLocation(expr.getLocation());
+                return;
+            }
             var struct = (WasmStructure) type.composite;
             var fieldIndex = context.classInfoProvider().getFieldIndex(expr.getField());
             if (fieldIndex >= 0) {

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

@@ -15,6 +15,8 @@
  */
 package org.teavm.backend.wasm.generate.gc.methods;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -209,7 +211,11 @@ public class WasmGCMethodGenerator implements BaseWasmFunctionRepository {
                 generateNativeMethodBody(method, function);
             }
         } catch (RuntimeException e) {
-            throw new RuntimeException("Failed generating method body: " + method.getReference(), e);
+            var buffer = new StringWriter();
+            var printWriter = new PrintWriter(buffer);
+            e.printStackTrace(printWriter);
+            diagnostics.error(new CallLocation(method.getReference()),
+                    "Failed generating method body due to internal exception: " + buffer.toString());
         }
     }
 

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

@@ -67,7 +67,7 @@ public abstract class WasmType {
 
         private final boolean nullable;
 
-        public Reference(boolean nullable) {
+        Reference(boolean nullable) {
             this.nullable = nullable;
         }
 

core/src/main/resources/org/teavm/backend/wasm/wasm-gc-runtime.js

@@ -19,6 +19,7 @@ TeaVM.wasm = function() {
     function defaults(imports) {
         let stderr = "";
         let stdout = "";
+        let exports;
         imports.teavm = {
             putcharStderr(c) {
                 if (c === 10) {
@@ -38,6 +39,9 @@ TeaVM.wasm = function() {
             },
             currentTimeMillis() {
                 return new Date().getTime();
+            },
+            dateToString(timestamp, controller) {
+                return stringToJava(new Date(timestamp).toString());
             }
         };
         imports.teavmMath = Math;
@@ -62,21 +66,25 @@ TeaVM.wasm = function() {
         }));
     }
 
+    function stringToJava(str) {
+        let sb = exports.createStringBuilder();
+        for (let i = 0; i < str.length; ++i) {
+            exports.appendChar(sb, str.charCodeAt(i));
+        }
+        return exports.buildString(sb);
+    }
+
     function createMain(instance) {
         return args => {
             if (typeof args === "undefined") {
                 args = [];
             }
             return new Promise((resolve, reject) => {
-                let exports = instance.exports;
+                exports = instance.exports;
                 let javaArgs = exports.createStringArray(args.length);
                 for (let i = 0; i < args.length; ++i) {
                     let arg = args[i];
-                    let javaArg = exports.createStringBuilder();
+                    exports.setToStringArray(javaArgs, i, stringToJava(args[i]));
-                    for (let j = 0; j < arg.length; ++j) {
-                        exports.appendChar(javaArg, arg.charCodeAt(j));
-                    }
-                    exports.setToStringArray(javaArgs, i, exports.buildString(javaArg));
                 }
                 try {
                     exports.main(javaArgs);

tests/src/test/java/org/teavm/classlib/java/time/TestClockTick.java

@@ -154,6 +154,7 @@ public class TestClockTick extends AbstractTest {
     }
 
     //-----------------------------------------------------------------------
+    @SkipPlatform(TestPlatform.WEBASSEMBLY_GC)
     public void test_tickSeconds_ZoneId() throws Exception {
         Clock test = Clock.tickSeconds(PARIS);
         assertEquals(test.getZone(), PARIS);